Аннотация

1.

Zhigzhitzhapova, S.V. Chemical composition of volatile organic compounds of Artemisia vulgaris L. (Asteraceae) from the Qinghai-Tibet Plateau / S.V. Zhigzhitzhapova, L.D. Radnaeva, Q.B. Gao et al. // Industrial Crops and Products. – 2016. – Vol. 83. – P. 462-469. https://doi.org/10.1016/j.indcrop.2015.12.083 (IF JСR=5,645 (3,181); Q1). https://www.webofscience.com/wos/woscc/full-record/WOS:000370894000059

Plants growing in different climate retain the general direction of the biosynthesis of the volatile organic compound (VOC). The aim of this study was to investigate the VOC composition in Artemisia vulgaris L. growing on the Qinghai–Tibet Plateau. The VOCs were isolated by hydrodistillation or by headspace extraction, and their composition was analyzed by gas chromatography–mass spectrometry (GC–MS). There were 96 VOCs identified in the samples, accounting for 91–97% of the total. Monoterpenes (80.33%) were the main components of VOCs released by headspace extraction. The major components of essential oil obtained by hydrodistillation were monoterpenes (44.49%) and sesquiterpenes (29.98%). The monoterpenes 1,8-cineole, camphor, and α- and β- thujones were the main VOCs detected after both hydrodistillation and headspace extraction. Sesquiterpenes (cis-davanone, germacrene D) also accounted for a significant proportion of compounds in the essential oil. A principal component analysis (PCA) based on the types of components of essential oils of A. vulgaris collected from different countries showed that the moisture conditions at the collection site was the main factor explaining variations in VOC composition, and were located between “European” and “Siberian” chemotype, which indicated that the essential oil profile does not fully reflect zonal climatic features.

2.

Stelmakh S.A., Ukshe A.E., Mognonov D.M., Novikova K.S., Grigor'eva M.N., Kayumov R.R., Bal'zhinov S.A., Dobrovolsky Y.A. Proton conductivity of new type medium-temperature proton exchange membranes // Ionics. – 2016. – Vol.22 (№10). – pp.1873–1880. Doi: 10.1007/s11581-016-1722-1 (IF JCR=1.754; Q2)

https://link.springer.com/content/pdf/10.1007/s11581-016-1722-1.pdf

This work reports on the analysis of physicochemical properties including proton conductivity of a new class of composite proton exchange membranes based on N-phenyl-substituted polyhexamethylene guanidine (PHMG) and poly-m-phenylene isophthalamide (phenylone) doped with phosphoric acid (PHMGP-PA) at different temperatures and environmental humidity. The presence of a strong ionic bond between protonated PHMGP and phosphoric acid anions allowed one to expect that the composite material is capable to retain phosphoric acid even in conditions of high humidity and temperature.

3.

Reshak, A. H. Electronic structure of monoclinic - Exploration of the Electronic Structure of Monoclinic α-Eu2(MoO4)3: DFT-Based Study and X-ray Photoelectron Spectroscopy / A.H. Reshak, Z.A. Alahmed, J. Bila, V.V. Atuchin, B.G. Bazarov, O.D. Chimitova, M.S. Molokeev, I.P. Prosvirin, A.P. Yelisseyev // J. Phys. Chem. C. – 2016, V. 120, № 19. – Р. 10559−10568. DOI: 10.1021/acs.jpcc.6b01489 (IF JCR 4.536 (2016); Q1).

https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b01489

The powder α-Eu₂(MoO₄)₃ sample was prepared by the solid-state reaction method. The phase purity of the final powder product was verified by X-ray diffraction analysis. The constituent element core levels and valence band are measured by X-ray photoelectron spectroscopy as a function of Ar⁺ ion (2.5 keV, 7–8 μA/cm²) bombardment time. The formation of Mo⁵⁺ and Mo⁴⁺ states at high bombardment times was detected. The Eu–O and Mo–O bonding was considered in comparison with other Eu³⁺- and Mo⁶⁺-containing oxides using binding energy difference parameters. The transparency range obtained for the pure α-Eu₂(MoO₄)₃ tablet is λ = 0.41–0.97 μm, as estimated at the transmission level of 5%. The short-wavelength cut edge in α-Eu₂(MoO₄)₃ is governed by the direct allowed optical transitions within the band gap of E_g = 3.74 eV (300 K). The band structure of α-Eu₂(MoO₄)₃ was calculated by ab initio methods and strongly different results were obtained for the spin up/down configurations. The Eu-4f states are located around 2.2 eV and −4.0 eV for spin up (↑) and the structures situated at around 6.5 and 5.5 eV for spin down (↓) configuration. The calculated spin magnetic moments are in excellent relation to the Slater-Pauling rule and within the Eu sphere the magnetic moment of 4f electrons is ∼5.99 μB.

4.

Kotova, I.Yu. New series of triple molybdates AgA3R(MoO4)5 (A = Mg, R = Cr, Fe; A = Mn, R = Al, Cr, Fe, Sc, In) with framework structures and mobile silver ion sublattices / I.Yu. Kotova, S.F. Solodovnikov, Z.A. Solodovnikova, D.A. Belov, S.Yu. Stefanovich, A.A. Savina, E.G. Khaikina // J. Solid State Chem. – 2016. – V. 238. – P. 121–128. http://dx.doi.org/10.1016/j.jssc.2016.03.003 (IF JCR 2.299; Q2).

https://www.sciencedirect.com/science/article/pii/S0022459616300780?via%3Dihub

Triple molybdates AgA₃R(MoO₄)₅ (A=Mg, R=Cr, Fe; A=Mn, R=Al, Cr, Fe, Sc, In) of the NaMg₃In(MoO₄)₅ type were synthesized and single crystals of AgMg3R(MoO₄)₅ (R=Cr, Fe) were grown. In their structures, the MoO4 tetrahedra, pairs and trimers of edge-shared (Mg, R)O₆ octahedra are connected by common vertices to form a 3D framework. Large framework cavities involve Ag+ cations disordered on three nearby positions with CN=3+1 or 4+1. Alternating (Mg, R)O₆ octahedra and MoO4 tetrahedra in the framework form quadrangular windows penetrable for Ag+ at elevated temperatures. Above 653–673 K, the newly obtained molybdates demonstrate abrupt reduction of the activation energy to 0.4–0.6 eV. At 773 K, AgMg3Al(MoO4)5 shows electric conductivity 2.5·10−2 S/cm and Ea=0.39 eV compatible with characteristics of the best ionic conductors of the NASICON type.

5.

Zolotova, E.S. Phase relations in the Na2MoO4–Cs2MoO4 and Na2MoO4–Cs2MoO4–ZnMoO4 systems, crystal structures of Cs3Na(MoO4)2 and Cs3NaZn2(MoO4)4 / E.S. Zolotova, V.N. Yudin, S.F. Solodovnikov, E.G. Khaikina, O.M. Basovich, I.V. Korolkov, I.Yu. Filatova // J. Solid State Chem. – 2016. – V. 233. – P. 23–29. https://doi.org/10.1016/j.jssc.2015.10.008 (IF JCR- 2.299; Q2).

https://www.sciencedirect.com/science/article/pii/S0022459615301973?via%3Dihub

The phase diagram of the Na2MoO4-Cs2MoO4 system was reinvestigated and a new intermediate compound, Cs3Na(MoO4)(2), melting incongruently at 510 degrees C was found. Its crystal structure (a=6.3461(2), c=8.2209(3) angstrom, sp. gr. P (3) over bar m1, Z=1, R=0.0131) belongs to the glaserite type. Taking into account these data, the subsolidus phase relations of the system Na2MoO4-Cs2MoO4-ZnMoO4 was studied at 420 degrees C. The filling vacancies in the tetrahedral Zn position of the Cs6Zn5(MoO4)(8) structure (sp. gr. 1 (4) over bar 3d, Z=2) following the scheme Zn2+ +square -> 2Na(+) was established to result in the continuous solid solution Cs6Zn5-x square Na-1-x(2x)(MoO4)(8) (0 <= x <= 1). With increasing the x value, the cubic lattice parameter of the solid solution increases linearly while its melting point decreases that testifies to destabilization of the Cs6Zn5(MoO4)(8) structure by a progressive Na+ insertion. In the structure of Cs3NaZn2(MoO4)(4) (a=12.3134(1) angstrom, R=0.0121), Mo04 and (Zn2/3Na1/3)O-4 tetrahedra share corners to form an open 3D framework. The cesium ions are disordered around the centers of the cuboctahedral cavities of the framework to form "clusters" of the central Cs(1) and four disordered Cs(2) positions.

6.

Tsyrenova, G.D. New ferroelastic K2Sr(MoO4)2: Synthesis, phase transitions, crystal and domain structures, ionic conductivity / G.D. Tsyrenova, E.T. Pavlova, S.F. Solodovnikov, N.N. Popova, T.Yu. Kardash, S.Yu. Stefanovich, I.А. Gudkova, Z.A. Solodovnikova, B.I. Lazoryak // // J. Solid State Chem. – 2016. – V. 237. – P. 64–71. https://doi.org/10.1016/j.jssc.2016.01.011 (IF JCR- 2.299; Q2).

https://www.sciencedirect.com/science/article/pii/S0022459616300123?via%3Dihub

K2Sr(MoO4)(2) crystals were synthesized and their properties examined. The distortive polymorphic transformations at 421 K (alpha (LT) -> beta(MT)) and 744 K (beta(MT)->gamma (HT)) of K2Sr(MoO4)(2) were studied. It has been shown that the transitions go in sequence from the high-temperature palmierite K2Pb(SO4)(2)-type gamma-phase (R (3) over barm) to an intermediate beta-phase with a probable incommensurate structure and then to a low-temperature alpha-phase. Domain structures peculiarities in ferroelastic alpha-K2Sr(MoO4)(2) have been investigated. The electrical conductivity of K2Sr(MoO4)(2) rises tenfold in the vicinity of the phase transition at 744 K that may be associated with a change conductivity path from quasi-one-dimensional to two-dimensional. The crystal structure of the alpha-phase (sp. gr. C2/c, a=14.318(3) angstrom, b=5.9337(12) angstrom, c=10.422(2) angstrom, beta=105.83(3)degrees, Z=4, R=0.0219) is similar to that of alpha-Pb-3(PO4)(2). Sr atoms are mainly located at site with the coordination number CN=8 (a tetragonal antiprism with bond lengths of 2.578(2)-2.789(2) angstrom) and K atoms are located at site with CN=9+1.

7.

Stelmakh S.A., Ukshe A.E., Mognonov D.M., Novikova K.S., Grigor'eva M.N., Kayumov R.R., Bal'zhinov S.A., Dobrovolsky Y.A. Proton conductivity of new type medium-temperature proton exchange membranes. Ionics V22, №10, 1873–1880 – 2016. Doi: 10.1007/s11581-016-1722-1 (IF=1.754, Q2) https://link.springer.com/content/pdf/10.1007/s11581-016-1722-1.pdf

Among polymer fuel cells (FC), there is a class of devices where phosphoric acid is used as electrolyte. The retention of acid in a polymer matrix is provided by binding a part of its molecules with basic groups of the polymer. Operating temperature for such medium-temperature FC can attain 150 °C due to high thermal stability and relatively high proton conductivity at low humidity [1]. Increased operating temperature of such FC provides many advantages as compared with low-temperature FC with solid polymer membranes, among which increased tolerance of catalytic materials to CO poisoning is one of the most important parameters. Moreover, high temperature facilitates the organization of water management in the fuel cell: the water does not condense in the liquid phase, and there is no danger of flooding of electrode pores during operation. Thus, CO-enriched hydrogen produced by the reforming of natural gas, other hydrocarbon feedstocks, and alcohols can be used for their work [2, 3].

Nowadays, the most developed polymer electrolyte membranes for medium temperature FC are based on various condensation polymers, composite materials, polymers with nitrogen-containing heterocycles, and complexes of polymers with acids [4]. For medium- and high-temperature FC, the most studied proton conductive membranes are those based on polybenzimidazole (PBI) and its derivatives doped by phosphoric acid [5, 6]. Such membranes show high thermal stability and proton conductivity in the absence of water. However, the major drawback of these materials is associated with acid leaching [7]. Condensation of water vapor formed by the FC operation, for example, by stopping and cooling the battery, leads to phosphoric acid leaching from the electrolyte and its degradation, and penetration of acid on the structural elements leads to corrosion of the latter [8–10]. Thus, the search for new polymer materials that can safely hold the acid anion is one of the important tasks of developing medium-temperature FC.

This work reports on the analysis of physicochemical properties including proton conductivity of a new class of composite proton exchange membranes based on N-phenyl-substituted polyhexamethylene guanidine (PHMG) and poly-m-phenylene isophthalamide (phenylone) doped with phosphoric acid (PHMGP-PA) at different temperatures and environmental humidity. The presence of a strong ionic bond between protonated PHMGP and phosphoric acid anions allowed one to expect that the composite material is capable to retain phosphoric acid even in conditions of high humidity and temperature.

2017

11.

Radnaeva, L. D. Fatty acid composition in the white muscle of Cottoidei fishes of Lake Baikal reflects their habitat depth/ L. D. Radnaeva, D. V. Popov, O. Grahl-Nielsen, I. V. Khanaev, S. V. Bazarsadueva, R. Käkelä. // Environmental Biology of Fishes. – 2017. – V. 100, Issue 12. – P. 1623-1641. https://doi.org/10.1007/s10641-017-0670-6 (IF JСR=1,844 (1,514); Q1). https://www.webofscience.com/wos/woscc/full-record/WOS:000417067100010

Lake Baikal is a unique freshwater environment with maximum depths over 1600 m. The high water pressure at the lakebed strengthens the solidifying effect of low water temperature on animal tissue lipids, and thus the effective temperatures in the depths of the lake equal subzero temperatures in shallow waters. Cottoidei species has colonized the different water layers of the lake, and developed different ecology and physiology reflected in their tissue biochemistry. We studied by gas chromatography the composition of fatty acids (FAs), largely responsible for tissue lipid physical properties, in the white muscle tissue of 13 species of the Cottoidei fish; five benthic abyssal, six benthic eurybathic and two benthopelagic species. The FA profiles reflected habitat depth. The muscles of the deepest living species contained little polyunsaturated FAs (PUFAs) and were instead rich in monounsaturated FAs (MUFAs), which may be due to occasional weak food web links to the PUFA-rich primary producers of the photic water layer, high MUFA supply from their benthic diet, and conversion of saturated FAs (SFAs) to MUFAs in the tissues of the fish. Despite the MUFA percentage among the abyssal species reached even 50% (by weight) of total FAs, the PUFA percentage still remained above 20% in every species. The muscle MUFA/SFA ratio correlated negatively with the PUFA content of the fish muscle, suggesting viscosity control integrating the fluidity contributions from the dietary PUFAs and potentially endogenous MUFAs.

12.

New solid electrolyte Na9Al(MoO4)6: Structure and Na+ ion conductivity / A.A. Savina, V.A. Morozov, A.L. Buzlukov, I.Yu. Arapova, S.Yu. Stefanovich, Y.V. Baklanova, T.A. Denisova, N.I. Medvedeva, M. Bardet, J. Hadermann, B.I. Lazoryak, E.G. Khaikina // Chem. Mater. – 2017. – Vol. 29. – P. 8901–8913. https://doi.org/10.1021/acs.chemmater.7b03989 (IF JCR - 9.466; Q1)

https://pubs.acs.org/doi/pdf/10.1021/acs.chemmater.7b03989

Solid electrolytes are important materials with a wide range of technological applications. This work reports the crystal structure and electrical properties of a new solid electrolyte Na9Al(MoO4)6. The monoclinic

Na9Al(MoO4)6 consists of isolated polyhedral [Al(MoO4)6]9− clusters composed of a central AlO6 octahedron sharing vertices with six MoO4 tetrahedra to form a three-dimensional framework. The AlO6 octahedron also

shares edges with one Na1O6 octahedron and two Na2O6 octahedra. Na3−Na5 atoms are located in the framework cavities. The structure is related to that of sodium ion conductor II-Na3Fe2(AsO4)3. High-temperature conductivity

measurements revealed that the conductivity (σ) of Na9Al(MoO4)6 at 803 K equals 1.63 × 10−2 S cm−1. The temperature behavior of the 23Na and 27Al nuclear magnetic resonance spectra and the spin-lattice relaxation rates of the 23Na nuclei indicate the presence of fast Na+ ion diffusion in the studied compound. At T<490 K, diffusion occurs by means of Na+ ion jumps exclusively through the sublattice of Na3−Na5 positions, whereas Na1 and Na2 become involved in the diffusion processes (through chemical exchange with the Na3−Na5 sublattice) only at higher temperatures.

13.

Luminescence properties upgrading via the structure and cation changing in AgxEu(2–x)/3WO4 and AgxGd(2–x)/3–0.3Eu0.3WO4 / V.A. Morozov, D. Batuk, M. Batuk, O.M. Basovich, E.G. Khaikina, D.V. Deyneko, B.I. Lazoryak, I.I. Leonidov, A.M. Abakumov, J. Hadermann // Chem. Mater. – 2017. – Vol. 29. – P. 8811–8823. https://doi.org/10.1021/acs.chemmater.7b03155 (IF - 9.466; Q1).

https://pubs.acs.org/doi/pdf/10.1021/acs.chemmater.7b03155

The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+ 0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal

structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,

0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2(x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations.

14.

Cs3LiZn2(WO4)4 and Rb3Li2Ga(MoO4)4: different filled derivatives of the cation-deficient Cs6Zn5(MoO4)8 structure / S.F. Solodovnikov, Z.A. Solodovnikova, E.S. Zolotova, Yu.M. Kadyrova, A.A. Savina, S.Yu. Stefanovich, E.G. Khaikina // Acta Crystallogr. – 2017. – Vol. C73. – C. 73. – P. 946–952. https://doi.org/10.1107/S205322961701378X (IF JCR - 4.099; Q1).

https://onlinelibrary.wiley.com/iucr/doi/10.1107/S205322961701378X

Two new compounds, namely cubic tricaesium lithium dizinc tetrakis(tetraoxotungstate), Cs₃LiZn₂(WO₄)₄, and tetragonal trirubidium dilithium gallium tetrakis(tetraoxomolybdate), Rb₃Li₂Ga(MoO₄)₄, belong to the structural family of Cs₆Zn₅(MoO₄)₈ (space group I3d, Z = 4), with a partially incomplete (Zn_5/6□_1/6) position. In Cs₃LiZn₂(WO₄)₄, this position is fully statistically occupied by (Zn_2/3Li_1/3), and in Rb₃Li₂Ga(MoO₄)₄, the 2Li + Ga atoms are completely ordered in two distinct sites of the space group I2d (Z = 4). In the same way, the crystallographically equivalent A⁺ cations (A = Cs, Rb) in Cs₆Zn₅(MoO₄)₈, Cs₃LiZn₂(WO₄)₄ and isostructural A₃LiZn₂(MoO₄)₄ and Cs₃LiCo₂(MoO₄)₄ are divided into two sites in Rb₃Li₂Ga(MoO₄)₄, as in other isostructural A₃Li₂R(MoO₄)₄ compounds (AR = TlAl, RbAl, CsAl, CsGa, CsFe). In the title structures, the WO₄ and (Zn,Li)O₄ or LiO₄, GaO₄ and MoO₄ tetrahedra share corners to form open three-dimensional frameworks with the caesium or rubidium ions occupying cuboctahedral cavities. The tetrahedral frameworks are related to that of mayenite 12CaO·7Al₂O₃ and isotypic compounds. Comparison of isostructural Cs₃MZn₂(MoO₄)₄ (M = Li, Na, Ag) and Cs₆Zn₅(MoO₄)₈ shows a decrease of the cubic lattice parameter and an increase in thermal stability with the filling of the vacancies by Li⁺ in the Zn position of the Cs₆Zn₅(MoO₄)₈ structure, while filling of the cation vacancies by larger Na⁺ or Ag⁺ ions plays a destabilizing role. The series A₃Li₂R(MoO₄)₄ shows second harmonic generation effects compatible with that of β′-Gd₂(MoO₄)₃ and may be considered as nonlinear optical materials with a modest nonlinearity.

15.

Synthesis, crystal structures and properties of the new compounds K7–xAg1+x(XO4)4 (X = Mo, W) / T.S. Spiridonova, S.F. Solodovnikov, A.A. Savina, Z.A. Solodovnikova, S.Yu. Stefanovich, B.I. Lazoryak, I.V. Korolkov, E.G. Khaikina // Acta Crysallogr. – 2017.– Vol. C73. – Р. 1071–1077. https://doi.org/10.1107/S2053229617015674 (IF JCR - 4.099; Q1).

https://onlinelibrary.wiley.com/iucr/doi/10.1107/S2053229617015674

Two new isostructural compounds, namely heptapotassium silver tetrakis (tetraoxomolybdate), K_7–xAg_1+x(MoO₄)₄ (0 ≤ x ≤ 0.4), and heptapotassium silver tetrakis(tetraoxotungstate), K_7–xAg_1+x(WO₄)₄(0 ≤ x ≤ 0.4), have been synthesized and found to crystallize in the polar space group P6₃mc (Z = 2) with the unit-cell dimensions a = 12.4188 (2) and c = 7.4338 (2) Å for K_6.68Ag_1.32(MoO₄)₄ (single-crystal data), and a = 12.4912 (5) and c = 7.4526 (3) Å for K₇Ag(WO₄)₄ (Rietveld analysis data). Both structures represent a new structure type, with characteristic [K1(XO₄)₆] `pinwheels' of K1O₆ octahedra and six XO₄ tetrahedra (X = Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are linked to each other through Ag1O₄ tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (Ag1O₄–X1O₄–empty octahedron–Ag1O₄). Ag1 is located almost at the centre of the largest face of its coordination tetrahedron and seems to have some mobility. The new structure type is related to the Ba₆Nd₂Al₄O₁₅ and CaBaSiO₄ types, and to other structures of the α-K₂SO₄–glaserite family. The differential scanning calorimetry (DSC) and second harmonic generation (SHG) results show that both compounds undergo first-order phase transformations to high-temperature centrosymmetric phases.

16.

A new double molybdate of erbium and zirconium, its crystalline structure and properties / B.G. Bazarov, J.G. Bazarova, Yu.L. Tushinova, L.A. Solovyov, S.G. Dorzhieva, E. Surenjav, J. Temuujin // Journal of Alloys and Compounds. – 2017. – Vol. 701. – P. 750 – 753. https://doi.org/10.1016/j.jallcom.2017.01.173 (IF - 3.133; Q1).

https://www.sciencedirect.com/science/article/pii/S0925838817301962?via%3Dihub

A new double molybdate of erbium and zirconium, Er₂Zr(MoO₄)₅ was synthesized by a simple solid-state reaction. The crystal structure was determined using powder X-ray diffraction data, the Rietveld method and the derivative difference minimization method (DDM). The new phase crystallizes in the orthorhombic space groupCmc2₁. Thedielectric properties and thermal expansion between 298 and 1073 K were investigated. The synthesized compound showed an electrical conductivity of about 10⁻² S cm⁻¹ at high temperature.

17.

Exploration of structural, thermal, vibrational and spectroscopic properties of new noncentrosymmetric double borate Rb3NdB6O12 / V.V. Atuchin, A.K. Subanakov, A.S. Aleksandrovsky, B.G. Bazarov, J.G. Bazarova, S.G. Dorzhieva, T.A. Gavrilova, A.S. Krylov, M.S. Molokeev, A.S. Oreshonkov, A.M. Pugachev, Yu.L. Tushinova, A.P. Yelisseyev // Advanced Powder Technology. – 2017. – V. 28, №5. – C. 1309–1315. https://doi.org/10.1016/j.apt.2017.02.019 (IF JCR - 2.659; Q1).

https://www.sciencedirect.com/science/article/pii/S0921883117300973?via%3Dihub

New noncentrosymmetric rare earth borate Rb₃NdB₆O₁₂ is found in the ternary system Rb₂O–Nd₂O₃–B₂O₃. The Rb₃NdB₆O₁₂ powder was fabricated by solid state synthesis at 1050 K for 72 h and the crystal structure was obtained by the Rietveld method. Rb₃NdB₆O₁₂ crystallized in space group R32 with unit cell parameters a = 13.5236(4), c = 31.162(1) Å, Z = 3. From DSC measurements, the reversible phase transition (I type) in Rb₃NdB₆O₁₂ is observed at 852–936 K. The 200 μm thick tablet is transparent over the spectral range of 0.3–6.5 μm and the band gap is found as E_g ∼ 6.29 eV. Nonlinear optical response of Rb₃NdB₆O₁₂ tested via SHG is estimated to be higher than that of K₃YB₆O₁₂. Blue shift of Nd luminescent lines is found in comparison with other borates. The vibrational parameters of Rb₃NdB₆O₁₂ are evaluated by experimental methods.

18.

Nonstoichiometry in the Systems Na2MoO4–MMoO4 (M = Co, Cd), Crystal Structures of Na3.36Co1.32(MoO4)3, Na3.13Mn1.43(MoO4)3 and Na3.72Cd1.14(MoO4)3, Crystal Chemistry, Compositions and Ionic Conductivity of Alluaudite-type Double Molybdates and Tungstates / S.F. Solodovnikov, Z.A. Solodovnikova, E.S. Zolotova, V.N. Yudin, O.A. Gulyaeva, Yu.L. Tushinova // Solid State Chem. – 2017. – Vol. 253. – P. 121–128. https://doi.org/10.1016/j.jssc.2017.05.031 (IF - 2.299; Q2).

https://www.sciencedirect.com/science/article/pii/S0022459617301998?via%3Dihub#f0015

As results of a powder XRD study of sintered samples of the systems Na₂MoO₄–MMoO₄ (M = Co, Cd) quenched in air from 873 K, the literature data on the phase formation andhomogeneity ranges of nonstoichiometric double molybdatesin these systems were corrected. The compounds aremonoclinic alluaudite-type Na_4-2xCo_1+x(MoO₄)₃ (0.05 ≤ x ≤ 0.30) and Na_4-2xCd_1+x(MoO₄)₃ (0.10 ≤ x ≤ 0.40), orthorhombic lyonsite-type Na_2-2yCo_2+y(MoO₄)₃ (0.05 ≤ y ≤ 0.25), andtriclinic Na_2-2zCo_2+z(MoO₄)₃ (0.10 ≤ z ≤ 0.40) of the Na₂Mg₅(MoO₄)₆ type. The temperature of the orthorhombic-to-triclinic phase transition was found to be 943 ± 10 K. Crystal structures of the alluaudite-type double molybdates (space group C2/c, Z = 4) with cobalt, manganese, and cadmium were determined. According to the atomic positionoccupations, the compositions for the crystals were found as Na_3.36Co_1.32(MoO₄)₃ (a = 12.6381(3), b = 13.4888(4), c = 7.1244(2) Å, β = 112.127(1)°_, R = 0.0207), Na_3.13Mn_1.43(MoO₄)₃(a = 12.7387(3), b = 13.6716(4), c = 7.1904(2) Å, β = 112.404(1)°,R = 0.0166), and Na_3.72Cd_1.14(MoO₄)₃ (a = 12.804(3), b = 13.913(3), c = 7.326(2) Å, β = 112.63(1)°_, R = 0.0158). The crystal chemistry and compositions of the alluaudite-type molybdates and tungstates were considered and mainly one-dimensional character of the sodium-ion transport was shown for them. The measured values of the ionic conductivity of sintered samples of Na_3.6M_1.2(MoO₄)₃ (M = Mg, Ni, Zn, Cd) and Na_3.6Mg_1.2(WO₄)₃ exceeds 10⁻³ S cm⁻¹ at 673 K.

19.

Savina A.A., Solodovnikov S.F., Belov D.A., Solodovnikova Z.A., Stefanovich S.Yu., Lazoryak B.I., Khaikina E.G. New alluaudite-related triple molybdates Na25Cs8R5(MoO4)24 (R = Sc, In): synthesis, crystal structures and properties // New J. Chem. 2017. Vol. 41. P. 5450–5457. DOI: 10.1039/c7nj00202e (IF JCR - 3.269; Q1)

.

https://pubs.rsc.org/en/content/articlepdf/2017/nj/c7nj00202e

New triple molybdates Na25Cs8R5(MoO4)(24) (R = Sc, In) were prepared as powders and ceramics by solid state reactions, and their single crystals were also obtained from melts by spontaneous crystallization. The structures were determined by single crystal XRD analysis. The electrical conductivity of ceramics was measured by impedance spectroscopy. The crystal structures were determined in monoclinic sp. gr. P2(1)/c, a = 14.0069(3) angstrom, b = 12.6498(3) angstrom, c = 28.6491(6) angstrom, beta = 90.007(1)degrees (Sc) and a = 14.0062(2) angstrom, b = 12.6032(2) angstrom, c = 28.7138(4) angstrom, b = 90.001(1)degrees (In). Together with triclinic Na25Cs8Fe5(MoO4)(24), the titled compounds form a distinctive family of pseudo-orthorhombic alluaudite-related structures with the parent sp. gr. Pbca. Its structural features are alluaudite-like polyhedral layers composed of pairs of edge-shared (R, Na)O-6 and NaO6 octahedra connected by bridging MoO4 tetrahedra. The layers are joined together by means of interlayer MoO4 tetrahedra, thus forming open 3D frameworks with cavities filled with Cs+ and Na+ ions. The manner of stacking layers is somewhat different from the alluaudite type. The compounds undergo phase transitions at 668 (Sc) and 725 (In) K accompanied by an abrupt increase of electrical conductivity presumably Na+-ionic in nature. Above these transitions, the conductivity is as high as 10(-3) S cm(-1), which makes Na25Cs8R5(MoO4)(24) (R = Sc, In) promising solid state electrolytes.

20.

Kholkhoev B.Ch., Baljinov S.A., Makotchenko V.G., Fedorov V.E., Farion I.A., Kozlova M.N., Timashev P.S., Burdukovskii V.F. Convenient approach to making nanocomposites based on a chitosan–poly(vinyl pyrrolidone) polymer matrix and a graphene nanofiller // J. Appl. Pol. Sci. – 2017. – V. 134. – № 27. – P. 45038. DOI 10.1002/app.45038 (IF - 3.125. Q2).

https://onlinelibrary.wiley.com/doi/10.1002/app.45038

Conducting, mechanically durable, elastic nanocomposite films were prepared with chitosan (CS) as the polymer matrix, graphene obtained from highly exfoliated graphite as the nanofiller, and poly(vinyl pyrrolidone) (PVP) as the stabilizer of the graphene sheets. The maximum graphene content in the composites without a loss of uniformity and other useful properties increased up to 4.0 wt %. The resulting composites were characterized by scanning electron microscopy, Raman spectroscopy, X-ray diffraction analysis, mechanical testing, and electrical conductivity testing to determine the effects of the addition of graphene on the morphology and mechanical and electrical properties of the CS–PVP–graphene nanocomposite films. In this study, we took an approach to making nanocomposites from the perspectives of green chemistry, environmental protection, regenerative medicine, and low cost.

21.

Oxidation of atrazine in aqueous media by solar- enhanced Fenton-like process involving persulfate and ferrous ion /M. Khandarkhaeva, A. Batoeva, D. Aseev, M. Sizykh, O. Tsydenova // Ecotoxicology and Environmental Safety.–2017.–Vol.137, №3.–P.35-41. https://doi.org/10.1016/j.ecoenv.2016.11.013 (IF JCR - 3.743, Q1)

https://www.sciencedirect.com/science/article/pii/S0147651316304663?via%3Dihub

The oxidation of s-triazines (using atrazine (ATZ) as a model compound) by a solar-enhanced Fenton-like process involving persulfate and ferrous ion was studied. A flow-through tubular photoreactor was employed for the experiments. The solar-enhanced oxidative system involving ferrous ion and persulfate (Solar/S₂O₈²⁻/Fe²⁺) showed the highest ATZ degradation efficiency when compared with other treatments (unactivated S₂O₈²⁻, Solar - sunlight only, S₂O₈²⁻/Fe²⁺, Solar/S₂O₈²⁻). Complete degradation of ATZ and 20% reduction in total organic carbon (TOC) content were observed after 30 min of the treatment. The in situ generated ^•ОН and SO₄^–• radicals were shown to be involved in ATZ oxidation using the radical scavengers methanol and tert-butyl alcohol. Furthermore, iron compounds were shown to act not only as catalysts but also as photo-sensitizers, as the introduction of ferrous ion into the reaction mixture led to an increased absorbance of the solution and expansion of the absorption spectrum into the longer wavelength spectral region.

22.

Khankhasaeva S., Dashinamzhilova E., Dambueva D. Oxidative degradation of sulfanilamide catalyzed by Fe/Cu/Al-pillared clays // Applied Clay Science. –2017. –Vol.146. –P.92-99. https://doi.org/10.1016/j.clay.2017.05.018.

(IF JCR - 3.065, Q1)

https://www.sciencedirect.com/science/article/pii/S0169131717302144.

An oxidative degradation of an antibiotic sulfanilamide with hydrogen peroxide was carried out in the presence of Fe/Cu/Al-pillared clays as heterogeneous Fenton type catalysts. Fe/Cu/Al-pillared clays were synthesized by intercalation of layered aluminosilicate containing 95 wt% montmorillonite with mixed polymeric Fe,Cu,Al-polyoxocations (Al/(Fe + Cu) = 10/1, OH/(Fe + Cu + Al) = 2.0 mol/mol). The materials were characterized by chemical analysis, low-temperature nitrogen adsorption and XRD. Fe/Cu/Al-pillared clays were active catalysts for sulfanilamide oxidation with hydrogen peroxide in aqueous solutions: in the presence of these materials oxidation rate increased significantly and conversion of sulfanilamide reached 99–100%. The effect of experimental factors such as H2O2/sulfanilamide molar ratio, the catalyst content, the reaction temperature and the pH on the conversion of sulfanilamide were studied. The optimal conditions for the catalytic oxidation of sulfanilamide in the presence of Fe/Cu/Al-pillared clay that permit achieving a high conversion of sulfanilamide and catalyst stability were determined. The Fe/Cu/Al-pillared clay could be used in four consecutive cycles without regeneration and loss of activity. The main intermediate products of sulfanilamide oxidative degradation were sulfanilic acid, benzenesulfonic acid, p-benzoquinone and aliphatic carboxylic acids. The results of the study proved that Fe/Cu/Al-pillared clays were effective catalysts for oxidative degradation of sulfanilamide in aqueous solutions.

23.

Chalov, S., Thorslund, J., Kasimov, N. et al. The Selenga River delta: a geochemical barrier protecting Lake Baikal waters // Regional Environmental Change 17, 2039–2053 (2017). https://doi.org/10.1007/s10113-016-0996-1 (IF JCR - 3,678, Q2)

https://link.springer.com/article/10.1007%2Fs10113-016-0996-1

The protection of Lake Baikal and the planning of water management measures in the Selenga River Basin require a comprehensive understanding of the current state and functioning of the delta’s ecosystem and hydrogeochemical processes. This is particularly relevant in light of recent and expected future changes involving both the hydrology and water quality in the Lake Baikal basin causing spatiotemporal changes in water flow, morphology, and transport of sediments and metals in the Selenga River delta and thus impacting on delta barrier functions. The central part of the delta had been characterized by sediment storage, especially along the main channels, causing a continuous lift of the delta surface by about 0.75 cm/year−1. Theses morphological changes have a significant impact on hydrological conditions, with historical shifts in the bulk discharge from the left to the right parts of the delta which is distinguished by a relatively high density of wetlands. Regions with a high density of wetlands and small channels, in contrast to main channel regions, show a consistent pattern of considerable contaminant filtering and removal (between 77 and 99 % for key metals), during both high-flow and low-flow conditions. The removal is associated with a significant concentration increase (2–3 times) of these substances in the bottom sediment. In consequence, geomorphological processes, which govern the partitioning of flow between different channel systems, may therefore directly govern the barrier function of the delta.

24.

2018

25.

Tykheev, Z.A. Constituents of Essential Oil and Lipid Fraction from the Aerial Part of Bupleurum scorzonerifoliumWilld. (Apiaceae) from Different Habitats / Z. A. Tykheev, S. V. Zhigzhitzhapova, F. Zhang, V. V. Taraskin, O. A. Anenkhonov, L. D. Radnaeva, S. Chen. // Molecules.– 2018. – Issue 23, No. 6, 1496. https://doi.org/10.3390/molecules23061496. (IF JCR – 4,411; Q2).

https://doi.org/10.3390/molecules23061496

The essential oils and lipid fraction extracted from the aerial parts of Bupleurum scorzonerifolium were determined by a GC-MS method. In total, up to 67 components were identified. cis-β-Ocimene, trans-β-ocimene, limonene, α-pinene, α-copaene, β-elemene, and caryophyllene oxide were recognized as consistent components of the essential oil extracted from the aerial parts of B. scorzonerifolium, regardless of the habitat. The content of these components varied from traces to a significant amount. The volume of the lipid fraction varied from 2.73 to 9.38%. In total, 23 components were identified, including 20 fatty acids, two sterols, and one ketone. The major fatty acid components identified were 16:0, 18:2n9, and 18:1n9. The total content of these fatty acids reached up to 76.19%. The lipid fraction of the aerial parts of B. scorzonerifolium predominantly contained MUFA and PUFA, which confirmed the pharmacological value of the species. The main factors affecting the composition of essential oils and lipid fractions of B. scorzonerifolium are environmental ones that determine the moisture supply to the plants in semiarid and arid areas.

26.

Incommensurately modulated structures and luminescence properties of the AgxSm(2−x)/3WO4 (x = 0.286, 0.2) scheelites as thermographic phosphors / V. Morozov, D. Deyneko, O. Basovich, E.G. Khaikina, D. Spassky, A. Morozov, V. Chernyshev, A. Abakumov and J. Hadermann // Chemistry of Materials. – 2018. – Vol. 30. – P. 4788−4798. https://doi.org/10.1021/acs.chemmater.8b02029 (IF JCR - 9.890; Q1).

https://pubs.acs.org/doi/full/10.1021/acs.chemmater.8b02029

Ag⁺ for Sm³⁺ substitution in the scheelite-type Ag_xSm_{(2–x)/3□(1–2x)/3}WO₄ tungstates has been investigated for its influence on the cation-vacancy ordering and luminescence properties. A solid state method was used to synthesize the x = 0.286 and x = 0.2 compounds, which exhibited (3 + 1)D incommensurately modulated structures in the transmission electron microscopy study. Their structures were refined using high resolution synchrotron powder X-ray diffraction data. Under near-ultraviolet light, both compounds show the characteristic emission lines for ⁴G_5/2 → ⁶H_J (J= 5/2, 7/2, 9/2, and 11/2) transitions of the Sm³⁺ ions in the range 550–720 nm, with the J = 9/2 transition at the ∼648 nm region being dominant for all photoluminescence spectra. The intensities of the ⁴G_5/2 → ⁶H_9/2 and ⁴G_5/2 → ⁶H_7/2 bands have different temperature dependencies. The emission intensity ratios (R) for these bands vary reproducibly with temperature, allowing the use of these materials as thermographic phosphors.

27.

New triple molybdate Rb2AgIn(MoO4)3: synthesis, framework crystal structure and ion transport behavior / T.S. Spiridonova, S.F. Solodovnikov, A.A. Savina, Yu.M. Kadyrova, Z.A. Solodovnikova, V.N. Yudin, S.Yu. Stefanovich, E.G. Khaikina //Acta Crysallogr. С. –2018. – Vol. 74. – N 12. – P. 1603–1609. https://doi.org/10.1107/S2053229618014717 (IF JCR - 8.678, Q1).

http://scripts.iucr.org/cgi-bin/paper?S2053229618014717

A new triple molybdate, Rb₂Ag_1+3xIn_1–x(MoO₄)₃ (0 ≤ x ≤ 0.02), was found in the course of a study of the system Rb₂MoO₄–Ag₂MoO₄–In₂(MoO₄)₃ and was synthesized as both powders and single crystals by solid-state reactions and spontaneous crystallization from melts. The structure of Rb₂Ag_1+3xIn_1–x(MoO₄)₃ (x ≈ 0.004) is of a new type crystallizing in the centrosymmetric space group Rc [a = 10.3982 (9), c = 38.858 (4) Å, Z = 12 and R = 0.0225] and contains (In,Ag)O₆ octahedra and distorted Ag1O₆ trigonal prisms linked by common faces to form [Ag(In,Ag)O₉] dimers connected to each other via MoO₄ tetrahedra into an open three-dimensional (3D) framework. Between two adjacent [Ag(In,Ag)O₉] dimers along the c axis, an extra Ag2O₆ trigonal prism with about 1% occupancy was found. The Ag1O₆ and Ag2O₆ prisms are located at levels of z ≈ 1/12, 1/4, 5/12, 7/12, 3/4 and 11/12, and can facilitate two-dimensional ionic conductivity. The 12-coordinate Rb atoms are in the framework cavities. The structure of Rb₂AgIn(MoO₄)₃is a member of the series of rhombohedral 3D framework molybdate structure types with a ≈ 9–10 Å and long c axes, which contain rods of face-shared filled and empty coordination polyhedra around threefold axes. Electrical conductivity of ceramics is measured by impedance spectroscopy. Rb₂AgIn(MoO₄)₃ undergoes a `blurred' first-order phase transition at 535 K with increasing electrical conductivity up to 1.1 × 10⁻² S cm⁻¹ at 720 K. Thus, the compound may be of interest for developing new materials with high ionic conductivity at elevated temperatures.

28.

Thermodynamic properties, Mössbauer study, and first-principles calculations of TlFe(MoO₄)₂ / A.V. Sobolev, E.S. Kozlyakova, I.S. Glazkova, V.A. Morozov, E.A. Ovchenkov, O.S. Volkova, A.N. Vasiliev, N.S. Ovanesyan, Y.M. Kadyrova, E.G. Khaikina, K. Molla, B. Rahaman, T. Saha-Dasgupta, S. Kamusella, H.-H. Klauss, I.A. Presniakov // Journal of Physical Chemistry. C. – 2018. – Vol. 122. – P. 19746−19755. DOI: 10.1021/acs.jpcc.8b05122 (IF JCR - 4.484, Q1).

https://pubs.acs.org/doi/10.1021/acs.jpcc.8b05122

We report the results of magnetization and specific heat measurements, a⁵⁷Fe Mössbauer study of hyperfine interactions and density functional theory calculations in TlFe(MoO₄)₂ demonstrating two magnetic phase transitions at T_N2 = 5.7 K and T_N1 = 6.2 K. In the asymptotical critical region T_N2 ≤ T ≤ T_N1, the temperature dependence of the average hyperfine magnetic field ⟨B_hf(T)⟩ at the ⁵⁷Fe nuclei is well-described by the power law ⟨B_hf(T)⟩ ∝ t^β with the static critical exponent β ≈ 0.37 inherent for a three-dimensional magnet. In this range, the Mössbauer spectra are described in terms of collinear spin-density-wave with the inclusion of high-order harmonics. The spectra of the low-temperature phase, below T_N2, are well-fitted by a single six-line Zeeman pattern reflecting the equivalence of magnetic sites occupied by Fe³⁺ ions in an antiferromagnetic structure. The first-principles calculations allowed estimation of the strength of main exchange interactions.

29.

Structural and spectroscopic properties of new noncentrosymmetric self-activated borate Rb₃EuB₆O₁₂ with B₅O₁₀ units / V.V. Atuchin, A.K. Subanakov, A.S. Aleksandrovsky, B.G. Bazarov, J.G. Bazarova, T.A. Gavrilova, A.S. Krylov, M.S. Molokeev, A.S. Oreshonkov, S.Yu. Stefanovich // Materials and Design. – 2018. – Vol. 140. – P. 488–494. https://doi.org/10.1016/j.matdes.2017.12.004 (IF JCR - 4.525, Q1).

https://www.sciencedirect.com/science/article/pii/S0264127517311097?via%3Dihub

New noncentrosymmetric double borate Rb₃EuB₆O₁₂ was designed and synthesized by the solid state reaction method, and its crystallographic parameters were obtained by Rietveld analysis. This borate crystallizes in the trigonal space groupR32 with cell parameters a = 13.4604(2) Å, c = 30.7981(5) Å,Z = 15. Its structure features a three-dimensional framework composed of the [B₅O₁₀]^{5 −} groups that are bridged by Eu-O polyhedra. The existence of B₅O₁₀ group in the structure was confirmed by vibrational spectroscopy. Rb₃EuB₆O₁₂ melts incongruently at 1101 K. The second harmonic generation effect of Rb₃EuB₆O₁₂ is 16 times higher than that of the α-quartz standard. In the luminescence spectrum, the domination of a single prominent narrow line from the hypersensitive ⁵D₀ - ⁷F₂ manifold of Eu^{3 +} ions is observed, while the ⁵D₀ - ⁷F₁ manifold and ultranarrow ⁵D₀ - ⁷F₀ line are of comparable peak intensity. These features are explained by a specific local symmetry of the Eu³⁺ ion within the crystal structure of Rb₃EuB₆O₁₂.

30.

Synthesis of new triple molybdates K₅RZr(MoO₄)₆ (R = Al, Cr, Fe, In, Sc) in the K₂MoO₄– R₂(MoO₄)₃–Zr(MoO₄)₂ systems, their structure and electrical properties / J.G. Bazarova, A.V. Logvinova, B.G. Bazarov, Yu.L. Tushinova, S.G. Dorzhieva, J. Temuujin // Journal of Alloys and Compounds. – 2018. – Vol. 741. – P. 834–839. https://doi.org/10.1016/j.jallcom.2018.01.208 (IF JCR - 3.779, Q1).

https://www.sciencedirect.com/science/article/pii/S0925838818302093?via%3Dihub

Phase relations in the K₂MoO₄–R₂(MoO₄)₃–Zr(MoO₄)₂ (R = Al, Cr, Fe, In, Sc) systems were studied by the method of intersecting cuts. The formation of new molybdates with compositions of K₅RZr(MoO₄)₆ (R = Al, Cr, Fe, In, Sc) were revealed. Synthesized molybdates crystallized in the hexagonal system, space group P6₃, Z = 2. Their thermal characteristics were determined. The electrical properties of K₅RZr(MoO₄)₆(R = Fe, In) were investigated using impedance spectroscopy(25–10⁶ Hz) in the temperature range 298–973 K. It was found that the dielectric parameters were temperature dependent and exhibited anomalies at high temperature (700–900 K) due to the phase transition. The electrical resistivity was reduced by 6 orders of magnitude from 10⁸ to 10² Om·cm.

31.

Optical spectroscopy of molybdates with composition Ln₂Zr₃(MoO₄)₉ (Ln: Eu, Tb) / D. Sofich, Yu.L. Tushinova, R. Shendrik, B.G. Bazarov, S.G. Dorzhieva, O.D. Chimitova, J.G. Bazarova // Optical Materials. – 2018. – Vol. 81. – P. 71–77. https://doi.org/10.1016/j.optmat.2018.05.028

(IF JCR - 2.320, Q2).

https://www.sciencedirect.com/science/article/pii/S0925346718302994?via%3Dihub

This study examined the luminescent properties of systems of double molybdates doped with Eu and Tb — this includes emission, excitation and absorption spectra. The compounds exhibited bright luminescence in the visible region due to the [Xe]4fⁿ → [Xe]4fⁿ transitions of rare-earth ions. The luminescence is excited both in the [Xe]4fⁿ → [Xe]4fⁿ bands of the rare-earth ions and in the wide band in the ultraviolet region related to the transitions within the Mo-O complex. Because of the energy transfer, the luminescence of Tb³⁺ and Eu³⁺ in doubly doped molybdates has had common excitation energies.

32.

Dudova D.S., Bardakova K.N., Kholkhoev B.Ch., Ochirov B.D., Gorenskaia E.N., Farion I.A., Burdukovskii V.F., Timashev P.S., Minaev N.V., Kupriyanova O.S. UV-laser formation of 3D structures based on thermally stable heterochain polymers // J. Appl. Pol. Sci. – 2018. – V. 135. – № 27. – P. 46463. DOI: 10.1002/app.46463 (IF JCR - 3.125, Q2).

https://onlinelibrary.wiley.com/doi/10.1002/app.46463

A new approach to making a photopolymeric composition was first elaborated in this work based on the use of poly-N,N′-(m-phenylene)isophtalamide as the heterochain polymer matrix together with 4,4′-diphenyl oxide diacrylamide as the crosslinking agent. Reproducible three-dimensional (3D) objects have been formed using a laser stereolithograph completed with a laser with wavelength of 405 nm. According to the thermogravimetric analysis, the thermal stability of the formed objects could be changed through a control from 260 to 405 °C. Moreover, it was proven that the tensile strength of samples of the crosslinked films reached 90.1 ± 3.2 MPa at the elongation at break of 12.4 ± 2.3%, depending on the forming parameters of such samples.

33.

Farion I.A., Burdukovskii V.F., Kholkhoev B.Ch., Timashev P.S., Chailakhyan R.K. Functionalization of chitosan with carboxylic acids and derivatives of them: Synthesis issues and prospects of practical use: A review // Express Polymer Letters. – 2018. – V. 12. – № 12. – P. 1081-1105. Doi: 10.3144/expresspolymlett.2018.95 (IF JCR - 4.161, Q1).

http://www.expresspolymlett.com/issue.php?y=2018&n=12

The review is devoted to the current state of the investigation works concerning chitosan functionalization with carboxylic acids and derivatives of them, including oxidized carbon nanoparticles such as graphene oxide, oxidized nano diamonds and oxidized carbon nanotubes. The examples of a use of chitosan derivatives in the pharmacology, the regenerative medicine, and other areas are given.

34.

Matafonova, G. Recent advances in application of UV light-emitting diodes for degrading organic pollutants in water through advanced oxidation processes: A review / G. Matafonova, V. Batoev // Water Research. – 2018. – Vol.132.– P.177-189. https://doi.org/10.1016/j.watres.2017.12.079 (IF JCR - 7.051, Q1)

https://www.sciencedirect.com/science/article/pii/S0043135417310941?via%3Dihub

Over the last decade, ultraviolet light-emitting diodes (UV LEDs) have attracted considerable attention as alternative mercury-free UV sources for water treatment purposes. This review is a comprehensive analysis of data reported in recent years (mostly, post 2014) on the application of UV LED-induced advanced oxidation processes (AOPs) to degrade organic pollutants, primarily dyes, phenols, pharmaceuticals, insecticides, estrogens and cyanotoxins, in aqueous media. Heterogeneous TiO₂-based photocatalysis in lab grade water using UVA LEDs is the most frequently applied method for treating organic contaminants. The effects of controlled periodic illumination, different TiO₂-based nanostructures and reactor types on degradation kinetics and mineralization are discussed. UVB and UVC LEDs have been used for photo-Fenton, photo-Fenton-like and UV/H₂O₂ treatment of pollutants, primarily, in model aqueous solutions. Notably, UV LED-activated persulfate/peroxymonosulfate processes were capable of providing degradation in DOC-containing waters. Wall-plug efficiency, energy-efficiency of UV LEDs and the energy requirements in terms of Electrical Energy per Order (E_EO) are discussed and compared. Despite the overall high degradation efficiency of the UV LED-based AOPs, practical implementation is still limited and at lab scale. More research on real water matrices at more environmentally relevant concentrations, as well as an estimation of energy requirements providing fluence-based kinetic data are required.

35.

36.

2019

37.

Mechanism of sodium-ion diffusion in alluaudite-type Na₅Sc(MoO₄)₄ from NMR experiment and ab initio calculations / N.I. Medvedeva, A.L. Buzlukov, A.V. Skachkov, A.A. Savina,
V.A. Morozov, Ya.V. Baklanova, I.E. Animitsa, E.G. Khaikina, T.A. Denisova, S.F. Solodovnikov // Journal of Physical Chemistry. C. – 2019. – V. 123. – P. 4729−4738.
DOI: 10.1021/acs.jpcc.8b11654 (IF JCR - 4.309, Q1).

https://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.8b11654

The crystal structure, electronic properties, and sodium diffusion mechanism in Na₅Sc(MoO₄)₄ were investigated using the powder X-ray diffraction, nuclear magnetic resonance, and electrical conductivity measurements, as well as ab initio calculations. Na₅Sc(MoO₄)₄ belongs to the family of alluaudite-type oxides Na_xM_y(AO₄)₃ (M = In, Sc, Mg, Cd, Zn, Mn, Fe, Co, and Ni; A = Mo, W, P, As, and S), which are now considered as promising materials for sodium-ion batteries. Our results demonstrate a considerable difference in the mechanism of Na⁺ ion transport in Na₅Sc(MoO₄)₄ and in previously studied alluaudite oxides, where one-dimensional sodium diffusion was suggested to occur through channels along the c-axis. The Na⁺ motion in Na₅Sc(MoO₄)₄ is found to be rather two-dimensionally occurring along the bc-plane. We believe that filling of the M-sublattice plays a key role in the mechanism of Na⁺ ion diffusion in alluaudite compounds. In particular, in Na₅Sc(MoO₄)₄ characterized by a low Sc-occupancy of the M-sublattice, the sodium ions located far from scandium are the first to be activated with increasing temperature and the activation energy for their jumps, E_a ≤ 0.3 eV, has one of the lowest values among Na-conductive materials.

38.

Exploration of structural, vibrational and spectroscopic properties of self-activated orthorhombic double molybdate RbEu(MoO₄)₂ / V.V. Atuchin, A.S. Aleksandrovsky, B.G. Bazarov, J.G. Bazarova, O.D. Chimitova, Yu.G. Denisenko, T.A. Gavrilova, A.S. Krylov, E.A. Maximovskiy, M.S. Molokeev, A.S. Oreshonkov, A.M. Pugachev, N.V. Surovtsev // Journal of Alloys and Compounds. – 2019. – Vol. 785. – Р. 692–697. https://doi.org/10.1016/j.jallcom.2019.01.013 (IF JCR - 4.175, Q1).

https://www.sciencedirect.com/science/article/pii/S0925838819300131?via%3Dihub

RbEu(MoO₄)₂ is synthesized by the two-step solid state reaction method. The crystal structure of RbEu(MoO₄)₂ is defined by Rietveld analysis in space group Pbcn with cell parameters a = 5.13502(5), b = 18.8581(2) and c = 8.12849(7) Å, V = 787.13(1) ų, Z = 4 (R_B = 0.86%). This molybdate possesses its phase transition at 817 K and melts at 1250 K. The Raman spectra were measured with the excitation at λ = 1064 and 514.5 nm. The photoluminescence spectrum is evaluated under the excitation at 514.5 nm. The absolute domination of hypersensitive ⁵D₀→⁷F₂ transition is observed. The ultranarrow ⁵D₀→⁷F₀ transition in RbEu(MoO₄)₂ is positioned at 580.2 nm being 0.2 nm blue shifted, with respect to that in Eu₂(MoO₄)₃

39.

The crustacean processing industry produces large quantities of waste by-products (up to 70%). Such wastes could be used as raw materials for producing chitosan, a polysaccharide with a unique set of biochemical properties. However, the preparation methods and the long-term stability of chitosan-based products limit their application in biomedicine. In this study, different scale structures, such as aggregates, photo-crosslinked films, and 3D scaffolds based on mechanochemically-modified chitosan derivatives, were successfully formed. Dynamic light scattering revealed that aggregation of chitosan derivatives becomes more pronounced with an increase in the number of hydrophobic substituents. Although the results of the mechanical testing revealed that the plasticity of photo-crosslinked films was 5–8% higher than that for the initial chitosan films, their tensile strength remained unchanged. Different types of polymer scaffolds, such as flexible and porous ones, were developed by laser stereolithography. In vivo studies of the formed structures showed no dystrophic and necrobiotic changes, which proves their biocompatibility. Moreover, the wavelet analysis was used to show that the areas of chitosan film degradation were periodic. Comparing the results of the wavelet analysis and X-ray diffraction data, we have concluded that degradation occurs within less ordered amorphous regions in the polymer bulk.

40.

Shpichka A., Butnaru D, Bezrukov E.A., Sukhanov R.B., Atala A., Burdukovskii V.F., Timashev P.S. Skin tissue regeneration for burn injury // Stem cell research & therapy. – 2019. – V. 10. – № 94. DOI: 10.1186/s13287-019-1203-3. (IF JCR - 4.659, Q1).

https://stemcellres.biomedcentral.com/track/pdf/10.1186/s13287-019-1203-3

The skin is the largest organ of the body, which meets the environment most directly. Thus, the skin is vulnerable to various damages, particularly burn injury. Skin wound healing is a serious interaction between cell types, cytokines, mediators, the neurovascular system, and matrix remodeling. Tissue regeneration technology remarkably enhances skin repair via re-epidermalization, epidermal-stromal cell interactions, angiogenesis, and inhabitation of hypertrophic scars and keloids. The success rates of skin healing for burn injuries have significantly increased with the use of various skin substitutes. In this review, we discuss skin replacement with cells, growth factors, scaffolds, or cell-seeded scaffolds for skin tissue reconstruction and also compare the high efficacy and cost-effectiveness of each therapy. We describe the essentials, achievements, and challenges of cell-based therapy in reducing scar formation and improving burn injury treatment.

41.

Khandarkhaeva M., Batoeva A., Sizykh M., Aseev D., Garkusheva N. Photo-Fenton-like degradation of bisphenol A by persulfate and solar irradiation // Journal of Environmental Management.–2019.–Vol.249.–109348. https://doi.org/10.1016/j.jenvman.2019.109348 (IF JCR - 4.005, Q1)

https://www.sciencedirect.com/science/article/pii/S0301479719310576?via%3Dihub

This work evaluates the feasibility of a solar-enhanced Fenton-like process using S₂O₈²⁻ (PS) and Fe²⁺ for the elimination of BPA, a model endocrine-disruption compound. This comparative study of BPA removal showed that among the approaches employed, the effectiveness of BPA degradation (10 mg/L) decreased in the order: Solar/PS/Fe²⁺> Solar/PS > PS/Fe²⁺> Solar/Fe²⁺> Solar. The complete degradation of BPA was achieved by Solar/PS/Fe²⁺ treatment at a [PS]:[BPA] ratio of 20 in less than t_30W 5 in deionised water. The high efficiency of the Solar/PS/Fe²⁺ process revealed a synergistic effect (ϕ = 2.38) between the applied activation agents on the formation of reactive oxygen species (ROS) and subsequent decomposition of BPA. The treatment was accompanied by total organic carbon (TOC) removal (44%) in 45 min. Sequential generation of reactive oxygen species has made Solar/PS/Fe²⁺ a kinetically effective process for removing BPA without accumulation of toxic intermediates. The reaction rate followed pseudo-first-order kinetics that increased with increasing PS and Fe²⁺ concentrations. Experimental evidence suggests that exposure to solar irradiation maintains suitable quantities of free Fe²⁺ in the reaction mixture, even at low catalyst concentrations (the molar ratio of [PS]:[Fe²⁺] varied from 1:0.01 to 1:0.08). The effects of HCO₃⁻, SO₄²⁻, and Cl⁻ were also examined. As expected, HCO₃⁻ and SO₄²⁻ inhibited BPA oxidation. The effect of Cl⁻ on the oxidation efficiency of BPA in Fenton-like systems depends not only on actual Cl⁻ concentrations but it is also highly influenced by molar ratios of Cl⁻ to oxidant and catalyst. Inhibition, which was caused by Cl⁻ in the mM range can be overcome by prolonging the reaction time or increasing the initial Fe²⁺concentration.

Finally, the efficiency of Solar/PS/Fe²⁺ process was examined in diluted natural surface water and wastewater effluent. On eliminating the buffering action of HCO₃⁻/CO₃²⁻ ions by lowering the pH value to 4.5, complete BPA degradation was achieved in all real water matrices.

42.

Popova, S. Simultaneous atrazine degradation and E. coli inactivation by UV/S₂O₈^2-/Fe²⁺ process under KrCl excilamp (222 nm) irradiation / S. Popova, G. Matafonova, V. Batoev // Ecotoxicology and Environmental Safety. – 2019. – Vol.169. – P. 169-177. DOI: 10.1016/j.ecoenv.2018.11.014 (IF JCR - 3.974, Q1)

https://www.sciencedirect.com/science/article/pii/S0147651318311503?via%3Dihub

This study is the first to reveal that the iron-catalyzed photo-activation of persulfate (UV/PS/Fe²⁺system) under mercury-free KrCl excilamp irradiation (222 nm) is capable of simultaneous degradation of an organic pollutant and inactivation of a microorganism in aqueous media using the herbicide atrazine (ATZ) and E. coli as model contaminants, respectively. Deionized water, natural water and wastewater effluents, contaminated with 4 mg/L ATZ and/or 10⁵ CFU/mL E. coli, were sequentially treated by direct UV, UV/PS and UV/PS/Fe²⁺ processes. Lowering the pH to 3.5 accelerated both the degradation and inactivation during the UV/PS/Fe²⁺ treatment of natural water. Comparison of the apparent UV dose-based pseudo first-order rate constants showed the negative effect of E. coli on ATZ degradation by decreasing rates in all of the examined water matrices. This can be due to the competitive effect between ATZ and bacterial cells for reactive oxygen species (ROS). By contrast, E. coli in the presence of ATZ was inactivated faster in natural water and wastewater (but not in deionized water), as compared to the case without ATZ. A scheme of possible synergistic inactivation under ROS exposure in water, containing ATZ, natural organic matter and chloride ions as primary constituents, was proposed. Radical scavenging experiments showed a major contribution of SO₄•^- to ATZ degradation by UV/PS/Fe²⁺ treatment of deionized water and natural water. The UV doses, required for 90% removal of ATZ from natural water and wastewater, achieve 160 mJ/cm² (pH 5.5) and concurrently provide 99.99% E. coli inactivation. These results make the UV/PS/Fe²⁺ system with narrow band UV light sources promising for simultaneous water treatment and disinfection.

43.

Matafonova G., Batoev V. Review on low- and high-frequency sonolytic, sonophotolytic and sonophotochemical processes for inactivating pathogenic microorganisms in aqueous media// Water Research. – 2019. – Vol.166. – 115085. https://doi.org/10.1016/j.watres.2019.115085 (IF JCR - 7.051, Q1)

https://www.sciencedirect.com/science/article/pii/S0043135419308590?via%3Dihub

Ultraviolet and ultrasound-based advanced oxidation processes (AOPs) are gaining considerable research attention for water treatment and disinfection. Compared to low-frequency ultrasound (LFUS, <100 kHz), high-frequency ultrasound (HFUS, >100 kHz and MHz range) for water disinfection remains much less investigated. The present review aims at surveying and discussing literature data on microbial inactivation in non-food aqueous media using HFUS alone and with AOPs. More specifically, the review covers sonophotolytic (US/UV) processes under sequential and simultaneous modes as well as sonophotochemical processes, where both low and high frequencies were applied. Addressing a state-of-the-art biomedical research, we have attempted to provide more insight into mechanical and sonochemical mechanisms of inactivation under ultrasonic exposure. Sonoporation, intracellular generation of reactive oxygen species (ROS), energy stimulation of aquaporins to deliver ROS, and injection of extracellular ROS into sonoporated cells have all been identified as primary ways of inactivation. Application of ultrasound in the 0.2-2 MHz range and mercury-free light sources to support the Minamata Convention on Mercury is an ongoing challenge for effective elimination of microbial pathogens from water and wastewater through sonophotolytic and sonophotochemical AOPs.

44.

Namsrai, O., Ochir, A., Baast, O., van Genderen, J.L., Muhar, A., Erdeni, S., Wang, J., Davaasuren, D., & Chonokhuu, S. (2019). Evaluating the management effectiveness of protected areas in Mongolia using the management effectiveness tracking tool. Environmental management, 63(2), 249-259. DOI:10.1007/s00267-018-1124-4. (IF JCR - 2.376, Q2)

https://link.springer.com/article/10.1007%2Fs00267-018-1124-4

The importance of management increases in the context of numerous and intensive inner and outer pressures on Protected Areas (PAs). The need to assess the management effectiveness (ME) in protected areas is increasing around the world. The ME assessment helps to improve the management of PAs and to develop a rational, long-term action plan. This study was conducted using the World Wildlife Fund for nature (WWF) Management Effectiveness Tracking Tools methodology (METT) to evaluate the ME of six PAs in central and eastern regions of Mongolia. The main purpose of this study was to assess ME and identify common threats of PAs across different natural zones and administrative areas in Mongolia. The results of this evaluation indicate that, the main threats faced by PAs in Mongolia are: (i) degradation of ecosystems, (ii) environmental pollution, and (iii) habitat fragmentation, resulting from over-exploitation and inappropriate use of natural resources. All six PAs examined have clear management goals and management decision-making systems however, their ME scores differ significantly. This research suggests that the administrative features of the individual PA influence management effectiveness and problems in the efficient implementation of management still need to be resolved.

2020

45.

Zhigzhitzhapova, S.V. Composition and antioxidant activity of the essential oil of Artemisia annua L /S.V. Zhigzhitzhapova, E.P. Dylenova, S.M. Gulyaev, T.E. Randalova, V.V. Taraskin, Z.A. Tykheev, L. D. Radnaeva // Natural Product Research. – 2020. – Vol. 34, Issue 18. – P. 2668-2671. https://doi.org/10.1080/14786419.2018.1548461 (JCR – 2,861 (1.928); Q2). https://www.tandfonline.com/doi/full/10.1080/14786419.2018.1548461

Artemisia annua L. is an annual Eurasian desert-steppe plant. The composition of essential oils found in Artemisia annua from Russian (Buryatian) flora was analyzed in this work using gas chromatography mass-spectrometry method. Artemisia ketone, β-selinene, caryophyllene, caryophyllene oxide, germacrene D were the main components of the analyzed essential oils. The comparison of own and literature data showed that the essential oils of A. annua conditionally could be divided into “Asian” and “European” groups. Our samples, referring to “Asian” profile, exhibited higher antiradical activity in comparison with data from previously published studies.

46.

Radnaeva, L.D. First data on lipids and microorganisms of deepwater endemic sponge Baikalospongia intermedia and sediments from hydrothermal discharge area of the Frolikha Bay (North Baikal, Siberia)/ L.D. Radnaeva, S.V. Bazarsadueva, V.V. Taraskin, A.K. Tulokhonov // Journal of Great Lakes Research. – 2020. – Vol. 46, issue 1. – P. 67-74 https://doi.org/10.1016/j.jglr.2019.09.021. (JCR – 2,48 (1,933); Q2). https://www.sciencedirect.com/science/article/abs/pii/S0380133019301832?via%3Dihub

In this report, we study lipid components (fatty acids with various degrees of unsaturation, aldehydes and sterols) of deep-water sponges Baikalospongia intermedia and sediments sampled using deep-water manned submersibles “Mir” at a hydrothermal vent of Frolikha Bay at depths of 400–450 m. It was found that unsaturated fatty acids predominate in the FA-composition of the sponges: very long chain demospongic acid 26:3, as well as monounsaturated 24:1 and isomers of acids 16:1 and 18:1. Among the saturated fatty acids in addition to the stearic 18:0, palmitic 16:0 and heptadecanoic 17:0 acids, significant amounts of acids of microbial origin (iso-palmitic i16:0, isostearic i18:0, oxy-stearic 10 h18) were detected. Using the method of mass spectrometry of microbial markers, we conclude, that the main microbial components of sponges B. intermedia and sediments from Frolikha Bay are methanotrophic microorganisms.

47.

Tykheev, Zh. A. Do Compositions of Lipid Fraction Correspond to Species Differentiation in Bupleurum L. (Apiaceae)? / Zh. A. Tykheev, O. A. Anenkhonov, S. V. Zhigzhitzhapova,V. V. Taraskin, L. D. Radnaeva, F. Zhang // Plants. – 2020. – Vol. 9(11), No.1407. https://doi.org/10.3390/plants9111407. (JCR – 3,935 (2.762), Q1). https://www.mdpi.com/2223-7747/9/11/1407

Bupleurum L. has been widely used in various medical systems as an agent with a wide range of activities. The qualitative composition and content of lipid fraction components of the aerial parts of B. longifolium and B. chinense were elucidated in this work. The available data on the fatty acids (FAs) in Bupleurum plants were compiled and compared with species differentiation in the genus. As a result, the content of FAs in the studied Bupleurum plant species only partially corresponded to the species differentiation and, in some cases, contradicted it. The prognostic value of Bupleurum’s species differentiation for the identification of the potential composition of FAs was insignificant, and it was limited only by particular groups of species. This suggests that a complete phytochemical study of Bupleurum species needs to be conducted to determine the composition of FAs and to identify which species have a similar composition.

48.

Urbagarova, B.M.,Chromones and coumarins from Saposhnikovia divaricata (Turcz.) Schischk. Growing in Buryatia and Mongolia and their cytotoxicity / B.M. Urbagarova, E.E. Shults, V.V. Taraskin, L.D. Radnaeva, T.N. Petrova, T.V. Rybalova, T.S. Frolova, A.G. Pokrovskii, J. Ganbaatar // Journal of Ethnopharmacology –2020. – Vol. 261. № 112517. https://doi.org/10.1016/j.jep.2019.112517. (JCR – 4,360 (3.69); Q1). https://www.sciencedirect.com/science/article/pii/S0378874119337778?via%3Dihub

Saposhnikovia divaricata (family Apiaceae) a traditional medicinal plant distributed in many provinces of China, is well known for the pharmaceutical value and has been used for rheumatic arthritis, and anxiety in children. Antiviral, antioxidant and antiproliferative activities were also mentioned. The application of this plant are recorded in the Chinese Medicine (CM) classical text the Shen Nong's Materia Medica (Shen Nong Ben Cao Jing). In this monograph S. divaricata (syn Radix Ledebouriella divaricata) is graded as a premium-grade herb, with their broad-spectrum of therapeutic applications for the treatment of cough, common cold, arthralgia, as well as in rheumatic disorders.

Total of 15 individual compounds: coumarins scopoletin 2, bergapten 3, isoimperatorin 4, marmesin 5, (+)-decursinol 9, (−)-praeruptorin B 10, oxypeucedanin hydrate 11, chromones: hamaudol 6, cimifugin 7, 5-О-methylvisamminol 8, chromone glycosides: prim-O-glucosylcimifugin 12, sec-O-glucosylhamaudol 13, 4′-O-β-D-glucopyranosyl-5-О-methylvisamminol 14, 4'-O-β-D-glucopyranosylvisamminol (15) and also polyyne compound panaxinol 1 were isolated and characterized. The structure of dihydropyranocoumarin 10 was confirmed by X-ray diffraction analyses. HPLC-UV method was used for determination of the content of most abundant chromones 7, 12 and 14 in the roots of S. divaricata, collected in Mongolia. Compounds 3-11 and 13, 14 were evaluated for their cytotoxicity with respect to model cancer cell lines. All the compounds were non-toxic in the hemolysis test. Conclusion: This report about the phytochemical profiles of S. divaricata growing in Mongolia and Buryatia led to the identification of 14 compounds including coumarins and chromones. The available coumarins and chromones may serve as new leads for the discovery of anticancer drugs.

49.

Coexistence of three types of sodium motion in double molybdate Na₉Sc(MoO₄)₆: ²³Na and ⁴⁵Sc NMR data and ab initio calculations /A.L. Buzlukov, I.Yu. Arapova, Ya.V. Baklanova, N.I. Medvedeva, T.A. Denisova, A.A. Savina, B.I. Lazoryak, E.G. Khaikina, M. Bardet // Phys. Chem. Chem. Phys. – 2020. – Vol. 22. – Р. 144–154. DOI: 10.1039/c9cp05249f (IF JCR - 6.732, Q1).

https://pubs.rsc.org/en/content/articlelanding/2020/CP/C9CP05249F

The rechargeable Na-ion batteries attract much attention as an alternative to the widely used but expensive Li-ion batteries. The search for materials with high sodium diffusion is important for the development of solid state electrolytes. We present the results of experimental and ab initio studies of the Na-ion diffusion mechanism in Na₉Sc(MoO₄)₆. The ion conductivity reaches the value of 3.6 × 10⁻² S cm⁻¹ at T ∼ 850 K. The ²³Na and ⁴⁵Sc NMR data reveal the coexistence of three different types of Na-ion motion in the temperature range from 300 to 750 K. They are activated at different temperatures and are characterized by substantially different dynamics parameters. These features are confirmed by ab initio calculations of activation barriers for sodium diffusion along various paths.

50.

Exploration of the structural and vibrational properties of the ternary molybdate Tl₅BiHf(MoO₄)₆ with Isolated MoO₄ units and Tl⁺ conductivity / V.G. Grossman, S.V. Adichtchev, V.V. Atuchin, B.G. Bazarov, J.G. Bazarova, N.V. Kuratieva, A.S. Oreshonkov, N.V. Pervukhina, N.V. Surovtsev // Inorg. Chem. – 2020. – Vol. 59. – P. 12681–12689. https://doi.org/10.1021/acs.inorgchem.0c01762 (IF JCR - 4.825, Q1).

https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.0c01762

The phase relations in the subsolidus region of the Tl₂MoO₄–Bi₂(MoO₄)₃–Hf(MoO₄)₂ system were studied with the “intersecting cuts” method. The formation of the novel ternary molybdate Tl₅BiHf(MoO₄)₆ is found in this ternary system. The compound has a phase transition at T_pt = 731 K (ΔH = −3.15 J/g) and melts at T_m = 871 K (ΔH = −41.71 J/g), as determined by a thermal analysis. Tl₅BiHf(MoO₄)₆ single crystals were obtained by the spontaneous nucleation method. The crystal structure of Tl₅BiHf(MoO₄)₆was revealed by structure analysis methods. This molybdate crystallizes in the trigonal space group R3̅c with the unit cell parameters a = 10.6801(4) Å, c = 38.5518(14) Å, V = 3808.3(2) ų, and Z = 6. The vibrational characteristics of Tl₅BiHf(MoO₄)₆ were determined by Raman spectroscopy. The Tl₅BiHf(MoO₄)₆ conductivity was measured at frequencies of 0.1, 1.0, and 10 kHz in the temperature range of 293–773 K; in this temperature range, the conductivity level was 10^–12–10^–7 S/cm.

51.

Thallium ionic conductivity of new thallium indium hafnium molybdate ceramics / V.G. Grossman, J.G. Bazarova, M.S. Molokeev, B.G. Bazarov // Ionics. – 2020. – Vol. 26, № 12. – P. 6157– 6165. Doi: 10.1007/s11581-020-03739-7 (IF JCR - 2.394, Q2).

https://link.springer.com/article/10.1007%2Fs11581-020-03739-7

In the process of studying the system Tl₂MoO₄–In₂(MoO₄)₃–Hf(MoO₄)₂, a new thallium indium hafnium molybdate was found. The crystal structure of the molybdate Tl₅InHf(MoO₄)₆ was determined in the centrosymmetric space groupR3¯¯¯3¯c (a = 10.63893 (5) Å, c = 38.1447(3) Å; V = 3739.04 (4) ų, Z = 6). The structure is a three-dimensional framework consisting of alternating (Hf,In)O₆-octahedra connected by МоО₄-tetrahedra. Each octahedron has common vertices with tetrahedra. The atoms arranged in this way form channels extended along with the a and b axes, in which thallium atoms are located. The conductivity behavior of Tl₅InHf(MoO₄)₆ ceramics was studied in the temperature range from 300 to 870 K. The conductivity of the heavy cations of thallium is activated with increasing temperature.

52.

New triple molybdate K₅ScHf(MoO₄)₆: Synthesis, properties, structure and phase equilibria in the M₂MoO₄–Sc₂(MoO₄)₃–Hf(MoO₄)₂ (M = Li, K) systems / V.G. Grossman, J.G. Bazarova, M.S. Molokeev, B.G. Bazarov // J. Solid State Chem. – 2020. – Vol. 283. – P. 121143. https://doi.org/10.1016/j.jssc.2019.121143 (IF JCR - 2.291, Q2).

https://www.sciencedirect.com/science/article/pii/S0022459619306486?via%3Dihub

Subsolidus phase relations in the M₂MoO₄–Sc₂(MoO₄)₃–Hf(MoO₄)₂ (M ​= ​Li, K) systems have been studied by the method of “intersecting cuts”. No new triple molybdates have been identified in the Li₂MoO₄–Sc₂(MoO₄)₃–Hf(MoO₄)₂system and a new triple molybdate K₅ScHf(MoO₄)₆ is formed in the K₂MoO₄–Sc₂(MoO₄)₃–Hf(MoO₄)₂ system. The structure of K₅ScHf(MoO₄)₆, have been determined in space group R3‾cthrough Rietveld analysis of X-ray powder diffraction data. The melting point of molybdate is 999 ​K. The compound has high ion conductivity (about 10⁻³ ​S ​cm⁻¹).

53.

New double holmium borates: Rb₃HoB₆O₁₂ and Rb₃Ho₂B₃O₉ /A.K. Subanakov, E.V. Kovtunets, B.G. Bazarov, S.G. Dorzhieva, J.G. Bazarova // Solid State Sciences. – 2020. – Vol. 105. – P. 106231. 10.1016/j.solidstatesciences.2020.106231 (IF JCR - 2.155, Q2).

Double borates Rb₃HoB₆O₁₂, Rb₃Ho₂B₃O₉ were newly synthesized by the sol–gel method and with solid state reactions. The crystal structures were determined from powder X-ray diffraction data. Rietveld's refinement of Rb₃HoB₆O₁₂ showed the following: R32, a = 13.4078 (2) Å, c = 30.3398 (4) Å, Z = 15. Rb₃Ho₂B₃O₉ species revealed: Pna21, a = 8.7139 (1) Å, b = 9.5760 (2) Å, c = 12.22335 (1) Å, Z = 2. Rb₃HoB₆O₁₂ and Rb₃Ho₂B₃O₉ incongruently and congruently melted at 818 °C and 908 °C, respectively. The phase transition for Rb₃HoB₆O₁₂ was established at 715 °C. The existence of B₅O₁₀ group in Rb₃HoB₆O₁₂ crystal structure was confirmed by an IR analysis.

54.

Sodium-ion diffusion in alluaudite Na₅In(MoO₄)₄ / A.L. Buzlukova, N.I. Medvedeva, Y.V. Baklanova, A.V. Skachkov, A.A. Savina, I.E. Animitsa, Т.А. Denisova , E.G. Khaikina // Solid State Ionics. – 2020. – Vol. 351. – P. 115328. Doi: 10.1016/j.ssi.2020.115328. (IF JCR - 2.886, Q2).
https://www.sciencedirect.com/science/article/pii/S0167273819305119?via%3Dihub

Alluaudite phases are very attractive as both cathode and electrolyte materials for rechargeable sodium-ion batteries. In this work, the combined experimental and DFT studies have been performed to establish the diffusion mechanism in alluaudite-like compound Na₅In(MoO₄)₄. The ionic conductivity was found to reach 3.3 × 10⁻⁴ S/сm at 687 K, with an activation energy of 0.66 eV. The sodium diffusion mechanisms have been revealed from the analysis of the ²³Na NMR spectra along with the DFT estimations of Na-ion migration barriers. Our results predict that one-dimensional diffusion of sodium in the separate channels along the c-axis is accompanied by the cross-linking jumps providing two-dimensional diffusion in the bc-plane. It is clearly demonstrated that the indium deficiency favors 2D diffusion, but sharply increases the energy barrier for 1D diffusion. Comparison of our results for Na₅In(MoO₄)₄ and related Na₅Sc(MoO₄)₄ shows that the type and deficiency of M-metal in the Na_xM_y(MoO₄)_z alluaudites can control the sodium diffusion. The present work highlights the key aspects of cation influence on the diffusion properties in alluaudite materials.

55.

Nephrite-bearing mining waste as a promising mineral additive in the production of new cement types / L.I. Khudyakova, E.V. Kislov, P.L. Paleev, I.Yu. Kotova // Minerals. – 2020. – Vol. 10, № 5. – P. 394–406. Doi: 10.3390/min10050394 (IF JCR - 2.618, Q2).

https://www.mdpi.com/2075-163X/10/5/394?utm_source=releaseissue&utm_medium=email&utm_campaign=releaseissue_minerals&utm_term=doilink49

Agrowing demand for products made of jewelry and ornamental stones, including nephrite, requires an increase in mining volume. However, only less than 30% of the extracted raw material is suitable for processing. The rest of the low grade nephrites are substandard and unclaimed, and they negatively a_ect various life spheres. In this regard, their involvement in industrial turnover is an actual task. One of the directions of mining waste use is production of building materials, in particular, cements. The low grade nephrite can act here as mineral additives. In the course of the research, the optimal amount of low grade nephrite waste additive was determined, which is 30% of the cement mass. The grinding time of a raw mix is 10 min. It was found that introduction of the additive a_ects the hydration activity of cement compositions. Compressive strength of the mixed cement is 25% higher than that of the control sample. At the same time, new phases in the hydrated cement were not recorded. Good physical and mechanical properties of the obtained cements are achieved when hardening in normal humidity conditions. Heat and humidity treatments do not facilitate the hydration processes in binary systems. The conducted studies have shown that low grade nephrite can be used as mineral additives in cement production. This will allow development of not only a new type of product, but also reduction of the negative impact of cement production on the environment.

56.

Ochirov B.D., Gorenskaia E.N., Kholkhoev B.Ch., Ayurova O.Zh., Burdukovskii V.F. Synthesis and thermo-oxidative degradation of acyclic polyimides // Polymer. – 2020. – V. 205. – 122692. Doi: 10.1016/j.polymer.2020.122692 (IF JCR - 4.430, Q1).

https://www.sciencedirect.com/science/article/pii/S003238612030522X?via%3Dihub

For the first time, film-forming aromatic acyclic polyimides were obtained as a result of in situ rearrangement or as a result of heat treatment of polycarboxyimidates by the Mumm-Hess mechanism. Intermediate polycarboxyimidates were prepared using the acid-catalyzed reaction of dicarboxylic acids and dinitriles in ionic liquids. The probable mechanism and the corresponding kinetic parameters of thermooxidative decomposition of acyclic polyimides were determined using NetzschThermokinetics 3 – multidimensional nonlinear regression software.

57.

Matafonova G., Batoev V. Dual frequency ultrasound: Strengths and shortcomings to water treatment and disinfection // Water Research. – 2020. –Vol. 182. –116016.

DOI: 10.1016/j.watres.2020.116016 (IF JCR - 9.130, Q1)

https://www.sciencedirect.com/science/article/pii/S0043135420305534?via%3Dihub

Since the early 2000s, dual-frequency ultrasound (DFUS) has received much attention for synergistically enhanced elimination of organic pollutants and pathogenic microorganisms from water. In the present review, we have surveyed recent developments in acoustic physics to elucidate the mechanism of synergistic effect under exposure of aqueous media to DFUS. Briefly, the nonlinear dynamics of microbubbles upon DFUS exposure produces additional frequencies, such as harmonics, subharmonics, ultraharmonics and combination frequencies. These increase the probability of bubbles collapse, thereby enhancing cavitation and generating more reactive oxygen species (ROS) for advanced oxidation processes (AOPs). Further, literature data on ROS generation, chemical degradation and microbial inactivation in aqueous media through DFUS alone and DFUS-based AOPs (involving oxidants or catalysts) have been discussed. In this regard, optimal frequency combination, sonoreactor type and transducer arrangement appear to be key parameters for achieving a high synergistic effect. Strengths and shortcomings of DFUS to water treatment and disinfection have been identified and future research directions have been proposed. Though most studies were conducted on pure (matrix-free) aqueous solutions, these AOPs could be applicable for treating real waters.

58.

Khankhasaeva S., Badmaeva S. Removal of p-aminobenzenesulfanilamide from water solutions by catalytic photo-oxidation over Fe-pillared clay // Water Research. –2020. –Vol.185. –116212. https://doi.org/10.1016/j.watres.2020.116212. (IF JCR - 9.130, Q1)

https://www.sciencedirect.com/science/article/pii/S0043135420307491?via%3Dihub

The catalytic photo-oxidation of p-aminobenzenesulfanilnamide (ABS) with hydrogen peroxide in the presence of Fe-pillared clay as heterogeneous catalyst has been investigated under UV-irradiation (λ_max = 254 nm). Fe-pillared clay was synthesized by intercalating the iron polyhydroxycomplexes into the interlayer space of a natural layered aluminosilicate - montmorillonite and a subsequent heat treatment at 500 °C. The catalyst was characterized by chemical analysis, low temperature nitrogen adsorption and XRD. The kinetics of photocatalytic oxidative degradation of ABS in aqueous solutions under various experimental conditions was studied. The dependence of the photo-oxidation rate on such experimental factors as pH, hydrogen peroxide concentration and catalyst content was established. The conversion of ABS was 100% and the mineralization efficiency was 52.3% at optimal conditions. The intermediate products of ABS photo-oxidation identified by HPLC were a sulfanilic acid, benzenesulfonamide, benzenesulfonic acid, hydroquinone, pyrocatechol, benzoquinone and aliphatic acids. Fe-pillared clay remained highly active in three consecutive catalytic cycles without regeneration. The results of the study suggested that the heterogeneous photo-system «Fe-pillared clay/H₂O₂/UV» was effective in the oxidative degradation of aminobenzenesulfanilnamide. This system may be of interest for use in organic wastewater treatment processes.

59.

Bilgaev, A., Dong, S., Li, F., Cheng, H., Sadykova, E., & Mikheeva, A. (2020). Assessment of the current eco-socio-economic situation of the Baikal region (Russia) from the perspective of the green economy development. Sustainability, 12(9), 3767. DOI:10.3390/su12093767. (IF JCR - 2.576, Q2)

https://www.mdpi.com/2071-1050/12/9/3767

Conducting research aimed at establishing the relationship between economic development and non-violation of the environment and developing optimal ways of their interaction is possible only by studying the features of regional development, which requires a comprehensive assessment of the ecological and socio-economic situation of the territories. The Baikal region includes Irkutsk Oblast, Republic of Buryatia, and Zabaykalsky Krai and occupies an exceptional place in Russia, due to Lake Baikal and unique natural features. The results of the assessment of the state of purity and quality of the environment indicate the emerging negative trends associated with water pollution, atmospheric air, and waste disposal in the Baikal region. Therefore, this article proposes the solutions to the problems in achieving sustainable development based on the implementation of the principles of the green economy, providing recommendations on how to reverse the current ecological and socio-economic situation of the Baikal region in a positive direction. Obtained practical assessments are essential for solving the problems of conservation and creating favorable conditions for the life of the population. Implementation of key government regulatory measures and changing existing approaches to managing the region based on the principles of the green economy will reduce the level of anthropogenic pressure on the environment.

60.

61. Sanzheev, E.D., Mikheeva, A.S., Osodoev, P.V., Batomunkuev, V.S., & Tulokhonov, A.K. (2020). Theoretical Approaches and Practical Assessment of Socio-Economic Effects of Desertification in Mongolia. International Journal of Environmental Research and Public Health, 17(11), 4068. DOI:10.3390/ijerph17114068. (IF JCR - 2.849, Q1)

https://www.mdpi.com/1660-4601/17/11/4068

In this paper, we consider the effects of desertification in Mongolia, where the area of degraded land has increased significantly in the recent decade. Currently, almost the entire territory of the country is subject to varying degrees of degradation. The intensity of the desertification processes in different natural zones is influenced by both natural climatic and anthropogenic factors. The purpose of this study is to evaluate the impact of desertification on environmental and socio-economic living conditions, as well as on living standards of the local population. In this work, for the first time, the socio-economic aspects of desertification have been studied on a common methodological basis in different Mongolian aimags over a ten-year period. In order to carry out in-depth research, we used the submeridional and sublatitudinal principles for selecting the model study areas, as well as specific criteria and expert assessment. We used a sociological survey as the main method, based on a designed questionnaire, which was translated into Mongolian. The questionnaire includes questions regarding the influence of desertification on traditional nomadic farming, health of family members, water supply of households, water quality, living standards, etc. The results of the sociological surveys made it possible to draw conclusions on the impact of desertification on households, to identify the main problems of local people, and to describe the dynamics of the socio-economic status of the population living in the model areas. Our studies have demonstrated the intensification of the impact of desertification processes in different natural zones, administrative-territorial units and settlement systems in Mongolia.

2021

62.

Tsybekmitova, G.T. Phytocenosis biodiversity at various water levels in mesotrophic Lake Arakhley, Lake Baikal basin, Russia / G.T. Tsybekmitova, L.D. Radnaeva, N.A. Tashlykova, V.G. Shiretorova, B.B. Bazarova, A.K. Tulokhonov, M.O. Matveeva // PeerJ. – 2021. –9:e11628. https://doi.org/10.7717/peerj.11628. (JCR IF – 2.98, Q2). https://peerj.com/articles/11628/

Small lakes have lower water levels during dry years as was the case in 2000–2020. We sought to show the biodiversity of plant communities at various water levels in Lake Arakhley. Changes in moisture content are reflected in the cyclical variations of the water level in the lake, which decreased approximately 2 m in 2017–2018. These variations affect the biological diversity of the aquatic ecosystems. We present the latest data on the state of the plant communities in this mesotrophic lake located in the drainage basin of Lake Baikal. Lake Arakhley is a freshwater lake with low mineral content and a sodium hydrocarbonate chemical composition. Changes in the nutrient concentration were related to precipitation; inflow volume and organic matter were autochtonous at low water levels. The most diverse groups of phytoplankton found in the lake were Bacillariophyta, Chlorophyta, and Chrysophyta. High biodiversity values indicate the complexity and richness of the lake’s phytoplankton community. A prevalence of Lindavia comta was observed when water levels were low and Asterionella formosa dominated in high-water years. The maximum growth depth of lacustrine vegetation decreased from 11.0 m to 4.0 m from 1967 to 2018. Decreasing water levels were accompanied by a reduction in the littoral zone, altering the communities of aquatic plants. The hydrophyte communities were monodominant in the dry years and were represented by Ceratophyllum demersum. The vegetation cover of the lake was more diverse in high-water years and variations in the lake’s water content altered the composition of biogenic substances. These changes were reflected in the lake’s phytocenosis.

63.

64.

Sha, Lou. Laboratory study of the efects of fexible vegetation on solute difusion in unidirectional fow / Sha Lou, Hao Wang, Hongzhe Liu, Guihui Zhong, Larisa Dorzhievna Radnaeva, Elena Nikitina, Gangfeng Ma, Shuguang Liu // Environmental Sciences Europe. – 2021. – Vol. 33. 80. https://doi.org/10.1186/s12302-021-00521-y. (JCR IF – 5.893, Q1). https://enveurope.springeropen.com/articles/10.1186/s12302-021-00521-y

Flexible vegetation is an important part of the riverine ecosystem, which can reduce flow velocity, change turbulence structure, and affect the processes of solute transport. Compared with the flow with rigid vegetation, which has been reported in many previous studies, bending of flexible vegetation increases the complexity of the flow–vegetation–solute interactions. In this study, laboratory experiments are carried out to investigate the influence of flexible vegetation on solute transport, and methods for estimating the lateral and longitudinal diffusion coefficients in the rigid vegetated flow are examined for their applications to the flow with flexible vegetation. The methods proposed in this study can be used to estimate the lateral and longitudinal diffusion coefficients in flows through both rigid and flexible vegetations using the effective submerged vegetation height.

65.

Bazarsadueva, S.V. The Comparison of Fatty Acid Composition and Lipid Quality Indices of Roach, Perch, and Pike of Lake Gusinoe (Western Transbaikalia) / S.V. Bazarsadueva, L.D. Radnaeva, V.G. Shiretorova, E.P. Dylenova // International Journal of Environmental Research and Public Health. – 2021. – 18. – 9032. https://doi.org/10.3390/ijerph18179032. (JCR IF – 3.390; Q1).

This paper describes the study of the fatty acid (FA) composition of three fish species (roach, perch, and pike) from Lake Gusinoe (western Transbaikalia). Using principal component analysis, the fatty acid composition of the studied fish species was shown to be species specific. The muscle tissue of roach, perch, and pike was found to contain high levels of polyunsaturated fatty acids (PUFA), including essential docosahexaenoic (DHA), eicosapentaenoic (EPA), and arachidonic acids. Indicators of nutritional quality based on the fatty acid composition showed that the values of the hypocholesterolemic/hypercholesterolemic (HH) ratio indices were sufficiently high. The atherogenicity (AI) and thrombogenicity (TI) indices, which are indicators for the nutritional value, were less than 1 in the studied fish. In terms of flesh lipid quality (FLQ), pike and perch had the highest proportion of total EPA + DHA. According to the obtained data for the composition of fatty acids in the muscle tissue of the studied fish from Lake Gusinoe, the anthropogenic load exerted on Lake Gusinoe has not yet statistically significantly affected the fish muscle quality.

66.

Potassium and thallium conductors with a trigonal structure in the M2MoO4–Cr2(MoO4)3–Hf(MoO4)2 (M = K, Tl) systems: Synthesis, structure, and ionic conductivity / V.G. Grossman, M.S. Molokeev, B.G. Bazarov, J.G. Bazarova // Journal of Alloys and Compounds. – 2021. – V. 873. – P. 159828. https://doi.org/10.1016/j.jallcom.2021.159828 (IF JCR - 4.650, Q1)

https://www.sciencedirect.com/science/article/pii/S0925838821012378?via%3Dihub

The triple molybdates M₅CrHf(MoO₄)₆ (M = K, Tl) and TlCrHf_0.5(MoO₄)₃ were found upon studying the corresponding ternary molybdate systems M₂MoO₄–Cr₂(MoO₄)₃–Hf(MoO₄)₂ (M = K, Tl) in the subsolidus region using X-ray powder diffraction. The crystal structures ofM₅CrHf(MoO₄)₆ (M = K, Tl) and TlCrHf_0.5(MoO₄)₃ are refined by Rietveld method. M₅CrHf(MoO₄)₆ (M = K, Tl) crystallizes in space group R3¯c with unit cell parameters: a = b = 10.45548 (5), c = 37.24614 (3) Å, V = 3526.14 (4) ų, Z = 6 for K₅CrHf(MoO₄)₆ and a = b = 10.53406 (12), c = 37.6837 (5) Å, V= 3621.39 ⁽9) ų, Z = 6 for Tl₅CrHf(MoO₄)₆. TlCrHf_0.5(MoO₄)₃crystallizes in space group R3¯ with unit cell parameters: a = b= 12.9710 (2), c = 11.7825 (2) Å, V = 1716.78 (6) ų, Z = 6. The thermal stability and electrical conductivity of the new compounds were investigated. Electrical conductivity measurements gave high values for the triple molybdatesM₅CrHf(MoO₄)₆ (M = K, Tl) (σ = 5.22 × 10⁻⁴ S / cm for K₅CrHf(MoO₄)₆, σ = 1.1 × 10⁻² S / cm for Tl₅CrHf(MoO₄)₆ at 773 K) and relatively low values for the triple molybdate TlCrHf_0.5(MoO₄)₃ (σ = 4.42 × 10⁻⁶ S / cm at 773 K).

67.

The crystal growth and properties of novel magnetic double molybdate RbFe5(MoO4)7 with mixed Fe3+/Fe2+ states and 1D negative thermal expansion† / O. D. Chimitova, B. G. Bazarov, J. G. Bazarova, V. V. Atuchin, R. Azmi, A. E. Sarapulova, D. Mikhailova, G. Balachandran, A. Fiedler, U. Geckle, Yu. Prots, A. C. Komarek, T. A. Gavrilova, I. P. Prosvirin, Yi Yang, Zheshuai Lin, M. Knappd and H. Ehrenberg // CrystEngComm. – 2021. – V. 23. – P. 3297–3307. DOI: https://doi.org/10.1039/D1CE00118C (IF JCR - 3.117, Q1).

https://pubs.rsc.org/en/content/articlelanding/2021/ce/d1ce00118c/unauth

Single crystals of new compound RbFe₅(MoO₄)₇ were successfully grown by the flux method, and their crystal structure was determined using the X-ray single-crystal diffraction technique. The XRD analysis showed that the compound crystallizes in the monoclinic space group P2₁/m, with unit cell parameters a = 6.8987(4), b = 21.2912(12) and c = 8.6833(5) Å, β = 102.1896(18)°, V = 1246.66(12) ų, Z (molecule number in the unit cell) = 2, R-factor (reliability factor) = 0.0166, and T = 293(2) K. Raman spectra were collected on the single crystal to show the local symmetry of MoO₄ tetrahedra, after the confirmation of crystal composition using energy dispersive X-ray spectroscopy (EDS). The polycrystalline samples were synthesized by a solid-state reaction in the Ar atmosphere; the particle size and thermal stability were investigated by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analyses. The compound decomposes above 1073 K in an Ar atmosphere with the formation of Fe(III) molybdate. The thermal expansion coefficient along the c direction has the value α = −1.3 ppm K⁻¹ over the temperature range of 298–473 K. Magnetic measurements revealed two maxima in the magnetization below 20 K, and paramagnetic behavior above 50 K with the calculated paramagnetic moment of 12.7 μB per formula unit is in good agreement with the presence of 3Fe³⁺ and 2Fe²⁺ in the high-spin (HS) state. The electronic structure of RbFe₅(MoO₄)₇ is comparatively evaluated using X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations.

68.

Exploration of structural, thermal and vibrational properties of new noncentrosymmetric double borate Rb3Tm2B3O9 / Subanakov A.K., Kovtunets E.V., Bazarov B.G., Pugachev A.M., Sofich D.O., Bazarova, J.G. // Solid state sciences. – 2021. – V. 120. – N. 106719..2021.106719. Doi: 10.1016/j.solidstatesciences (IF JCR - 3.059, Q2).

https://www.sciencedirect.com/science/article/pii/S1293255821001874?via%3Dihub

Double borate Rb₃Tm₂B₃O₉ was newly synthesized by solid-state reaction. The crystal structure of Rb₃Tm₂B₃O₉ was refined by Rietveld's method: Pna2₁, a = 8.6648(1),b = 9.5238(1), c = 12.1722(1) Å, Z = 4. The crystal structure of Rb₃Tm₂B₃O₉ consists of -[Tm₂O₉]_∞- chains along the “a” axis. BO₃ triangles linked chains in a three-dimensional framework. Rubidium atoms occupied empty ones in channels. The thermal behavior of Rb₃Tm₂B₃O₉ was studied in detail in between 25 and 1200 °C by DSC and TG methods. Rb₃Tm₂B₃O₉ was congruently melted at 886 °C. The band gap is found as E_g ∼5.14 eV. Nonlinear optical response of Rb₃Tm₂B₃O₉ tested via SHG is estimated to be lower than that of KDP. The existence of BO₃ groups in Rb₃Tm₂B₃O₉crystal structure has been confirmed by an IR analysis.

69.

Na₉In(MoO₄)₆: synthesis, crystal structure and Na+ ion diffusion/
Buzlukov A.L., Arapova I.Yu., Baklanova Ya.V., Savina A.A., Morozov V.A., Bardet M., Lazoryak B.I., Khaikina E.G., Denisova T.A., Medvedeva N.I. // Ionics. 2021. Vol. 27, № 10. P. 4281–4293. DOI: 10.1007/s11581-021-04226-3 (IF JCR - 2.817, Q2)

https://link.springer.com/article/10.1007%2Fs11581-021-04226-3

Fundamental studies of the materials with fast sodium mobility are important for the development of energy storage systems. This article presents the results of experimental studies of Na-conducting oxide Na₉In(MoO₄)₆. This compound crystallizes in rhombohedral symmetry with the space group R 3¯¯¯3¯ c and the unit cell parameters: a = 15.08695(6) and c = 19.1701(2) Å. Impedance spectroscopy measurements show that Na₉In(MoO₄)₆ is an ionic conductor with a conductivity of about 2.1 × 10⁻² Sm·cm⁻¹ at 803 K. The ²³Na NMR data reveal the coexistence of three types of sodium motion. These motional processes are activated at different temperatures and are characterized by substantially different nature and dynamics characteristics.

70.

Concretes made of magnesium-silicate rocks / L.I. Khudyakova, E.V. Kislov, I.Y. Kotova, P.L. Paleev // Minerals. – 2021. – V. 11. – Р. 441–457. https://doi.org/10.3390/min11050441 (IF JCR - 2.380, Q2)

https://www.mdpi.com/2075-163X/11/5/441/htm

At present, there is a shortage of high-quality feedstock to produce widely used building materials-concretes. Depletion of natural resources and growing restrictions on their extraction, in connection with environmental protection, necessitate the search for an equivalent replacement for conventional raw materials. Magnesium-silicate rocks are a waste of the mining industry. We researched the possibility of using these rocks as coarse and fine aggregates in heavy concrete production. Following the requirements of the national standards, we studied the physical and mechanical characteristics of the obtained material. It was found that the strength of concrete, made of magnesium-silicate rock coarse aggregate, at the age of 28 days of hardening is within 28 MPa, while the strength of the control sample is 27.3 MPa. Replacing quartz sand with dunite sand also leads to an increase in concrete strength (similar to 4%). Complete replacement of aggregates facilitates an increase in strength by 15-20% than the control sample. At the same time, the density of the obtained materials becomes higher. Concretes have a dense structure that affects their quality. Concrete water absorption is within 6%. The fluxing coefficient is 0.85-0.87. The application of magnesium-silicate rocks in concrete production enables the complete replacement of conventional aggregates with mining waste without reducing the quality of the obtained materials. Furthermore, the issues of environmental protection in mineral deposit development are being addressed.

71.

Farion I.A., Burdukovskii V.F., Kholkhoev B.Ch., Timashev P.S. Unsaturated and thiolated derivatives of polysaccharides as functional matrixes for tissue engineering and pharmacology: A review // Carbohydrate Polymers. – 2021. – V.259. – 117735. Doi: 10.1016/j.carbpol.2021.117735 (IF JCR - 9.381, Q1).

https://www.sciencedirect.com/science/article/pii/S0144861721001223?via%3Dihub

This review examines investigations into the functionalization of polysaccharides by substituents containing multiple (C=C) bonds and thiol (SH) groups that are prone to (co)polymerization in the presence of thermal, redox and photoinitiators or Michael addition reactions. A comparative analysis of the approaches to grafting the mentioned substituents onto the polysaccharide macromolecules was conducted. The use of the modified polysaccharides for the design of the 3D structures, including for the development of the pore bearing matrixes of cells or scaffolds utilized in regenerative medicine was examined. These modified polymers were also examined toward the design of excipient matrixes in pharmacological compositions, including with controllable release of active pharmaceuticals, as wel as of antibacterial and antifungal agents and others. In addition, a few examples of the use of modified derivatives in other areas are given.

72.

Bardakova K.N., Kholkhoev B.Ch., Farion I.A., Epifanov E.O., Korkunova O.S., Efremov Y.M., Minaev N.V., Solovieva A.B., Timashev P.S., Burdukovskii V.F. 4D printing of shape-memory semi-interpenetrating polymer networks based on aromatic heterochain polymers // Advanced Materials Technologies. – 2021. (Early Access).

DOI 10.1002/admt.202100790 (IF JCR - 7.848, Q1).

https://onlinelibrary.wiley.com/doi/10.1002/admt.202100790

Most of the presently known thermosensitive shape-memory polymers suitable for 4D printing have insufficient mechanical strength and thermal stability that restricts their potential areas of application. Here, new photosensitive compositions (PSCs) based on aromatic heterochain polymers – poly-N,N′-(m-phenylene)isophthalamide (MPA) or poly-2,2′-(p-oxydiphenylene)-5,5′-dibenzimidazole (OPBI) – for DLP printing are proposed. Thermal post-curing and supercritical carbon dioxide (scCO2) are used for post-processing of the structures. During the scCO2 treatment the removal of unreacted monomeric component (N,N-dimethylacrylamide) and its uncrosslinked oligomers is accompanied by the preservation of the initial degree of crosslinking. The more stable shrinkage is observed for the combined post-processing method (T°+scCO2) in the case of OPBI-PSC and after the heat treatment for MPA-PSC specimens. The method of post-processing and the nature of the heterochain polymer strongly affect the mechanical properties and thermal resistance of the structures. The tensile strength has the maximum value after the thermal post-treatment (101.1 ± 7.1 and 78.4 ± 5.1 MPa of OPBI-PSC and MPA-PSC, respectively). The intense destruction of the materials is observed at 393 and 408 °C for MPA-PSC and OPBI-PSC, respectively. Moreover, the 4D-printed structures exhibit excellent shape memory performance at transition temperatures >100 °C, thus have a great potential for the use in aerospace, robotics, sensorics.

73.

S.A. Stelmakh, M.N. Grigor’eva, N.M. Garkusheva, S.N. Lebedeva, O.S. Ochirov, D.M. Mognonov, S.D. Zhamsaranova, V.B. Batoev. Studies of new biocidal polyguanidines: antibacterial action and toxicity. Polymer bulletin, V78, №4. 2021, P. 1997-2008. Doi 10.1007/s00289-020-03197-1 (IF= 2.870, Q2)

https://link.springer.com/content/pdf/10.1007/s00289-020-03197-1.pdf

The aim of this study was to obtain new water-soluble polyguanidines, assess their antimicrobial properties with respect to the test objects of Escherichia coli and Bacillus cereus and establish the hazard class regulated in the territory of the Russian Federation. Polymers obtained in high yields by the method of polycondensation in the melt of the corresponding monomers and characterized by the methods of IR spectroscopy and elemental analysis. Serial dilution–agar plate procedure was performed in order to estimate antibacterial effects. The biocidal properties of the samples were estimated by the percentage reduction of microorganisms (% reduction). To determine the acute toxicity, a toxicometric assessment and symptoms of intoxication upon oral administration of a single dose were carried out in laboratory animals. New water-soluble guanidine-containing polymers with a number average molecular weight of 660–1040 Da were obtained. Copolymers with a low degree of substitution (10–20%) exhibit high antimicrobial activity among N-phenyl-substituted samples. As a result of the substituent increase in the polymer chain, their activity in relation to the studied bacteria is linearly decreased to a level comparable to the test sample. In contrast to the N-octyl-substituted copolymers, gram-positive bacterium B. cereus is more susceptible to N-phenyl-substituted samples. Substances after intragastric injection belong to the fourth class of toxicity (LD₅₀ > 300 ≤ 2000 mg/kg) according to the requirements of tabulation of toxicity classes regulated in the territory of the Russian Federation. The combination of low toxicity with a high level of antibacterial activity of new guanidine-containing polymers suggests the possibility of obtaining new effective disinfectants.

74.

Degradation of Bisphenol A in Aqueous Solution by Photo-Fenton-like Process Using UV KrCl Excilamp / D. Aseev, A. Batoeva, М. Sizykh, D. Olennikov, G. Matafonova // Int. J. Environ. Res. Public Health, 2021, 18, 1152. https://doi.org/10.3390/ijerph18031152 (IF JCR - 3.39, Q1).

https://www.mdpi.com/1660-4601/18/3/1152

Bisphenol A (BPA), a precursor to important plastics, is regarded as a common aquatic micropollutant with endocrine-disrupting activity. In the present study, we explored the capability of a UV KrCl excilamp (222 nm) to degrade BPA by a photo-Fenton-like process using persulfate under flow-through conditions. The first-order rate constants of degradation were obtained and the mineralization of dissolved organic carbon (DOC) was estimated. The results showed complete BPA degradation and high DOC mineralization (70–97%). A comparative analysis of degradation rates and DOC removal in the examined systems (UV, Fe²⁺/S₂O₈²⁻, UV/S₂O₈²⁻ and UV/Fe²⁺/S₂O₈²⁻) revealed a significant synergistic effect in the photo-Fenton-like system (UV/Fe²⁺/S₂O₈²⁻) without the accumulation of toxic intermediates. This indicated that the BPA was oxidized via the conjugated radical chain mechanism, which was based on the photo-induced and catalytic processes involving HO^• and SO₄^−• radicals. The primary intermediates of BPA degradation in the UV/Fe²⁺/S₂O₈²⁻ system were identified by HPLC/MS and the oxidation pathway was proposed. The high performance of the photo-Fenton-like process employing a quasi-monochromatic UV radiation of a KrCl excilamp offers promising potential for an efficient removal of such micropollutants from aqueous media.

75.

Budaev S.L., Batoeva A.A., Tsybikova B.A., Khandarkhaeva M.S., Aseev D.G. Photochemical degradation of thiocyanate by sulfate radical-based advanced oxidation process using UVС KrCl-excilamp // J. Environ. Chem. Eng., 2021, 9 (4), 105584. https://doi.org/10.1016/j.jece.2021.105584 (IF - 5.909, Q1)

https://www.sciencedirect.com/science/article/pii/S2213343721005613?via%3Dihub

The degradation of thiocyanates (SCN⁻) by UV-C-activated persulfate (PS) in the presence of ferric ion (Fe³⁺) was investigated. As a source of monochromatic far-UV-C irradiation (222 nm), mercury-free KrCl excimer lamp was used. Results showed that compared with direct photolysis, UVC/ PS and PS/ Fe³⁺, the combined UVC/ PS/ Fe³⁺ treatment had the highest initial reaction rate ω₀ and removal efficiency. 99.99% conversion of thiocyanates (100 mg/L of initial concentration) was achieved in 40 min. The addition of Fe³⁺ in the UVC/ PS treatment was found to reduce energy consumption (calculated as amount of oxidized thiocyanates per consumed electrical energy) by 4.5 times, while only a 30% difference between direct photolysis and UVC/ PS was observed. The high efficiency of the UVC/ PS/ Fe³⁺ process revealed a synergistic effect (synergy index ƒ = 1.98). The effect of the initial SCN⁻, PS, and Fe³⁺ molar ratios and UV-C exposure time on SCN⁻ removal in UVC/ PS/ Fe³⁺ was further investigated. It was found that at molar ratios [S₂O₈^2–]:[SCN⁻] = 3:1 and [S₂O₈^2–]^:[Fe³⁺] = 1:0.1, effective decomposition of SCN⁻ in a wide initial concentration range (from 50 to 500 mg/L or 0.86–8.6 mM) can be achieved. The strong role of ^•OH and SO₄^•− in the removal of SCN⁻ was confirmed by the addition of radical scavengers. It was demonstrated that the presence of Cu²⁺ in simulated gold mine wastewater effluents neutralizes the inhibitory effects that S₂O₃^2– and NH₄⁺ have on the degradation process.

76.

Popova S., Tsenter I., Garkusheva N., Beck S.E., Matafonova G., Batoev V. Evaluating (sono)-photo-Fenton-like processes with high-frequency ultrasound and UVA LEDs for degradation of organic micropollutants and inactivation of bacteria separately and simultaneously // J. Environ. Chem. Eng. – 2021. – V. 9. – 105249. https://doi.org/10.1016/j.jece.2021.105249 (IF JCR - 5.909, Q1)

https://www.sciencedirect.com/science/article/pii/S2213343721002268?via%3Dihub

This study reports the performance of high-frequency ultrasound (US, 1.7 MHz), coupled with a photo-Fenton-like process using persulfate and UV LEDs (UV/PS/Fe²⁺), for eliminating organic micropollutants and bacteria separately and simultaneously in deionized and natural water. Water matrices, containing atrazine (ATZ)/bisphenol A (BPA)) and Escherichia coli/Enterococcus faecalis), were sequentially treated by UV/PS/Fe²⁺ and UV/US/PS/Fe²⁺ processes. The highest degradation rates by UV/US/PS/Fe²⁺ process were found for BPA in both matrices, achieving complete removal and synergistic effects (φ>1). In terms of inactivation, this process was most efficient in deionized water for reducing E. coli and E. faecalis by 3 and 5 logs, respectively. The addition of bacteria inhibited the degradation in both matrices by decreasing the pseudo first-order rate constants up to one order of magnitude. In turn, the addition of micropollutants delayed the inactivation to various extents only in deionized water. In natural water, the co-existence of micropollutants accelerated the inactivation of E. coli, reaching 100% in 5 min with BPA and 7 min with ATZ (vs. 10 min without ATZ or BPA). The more resistant E. faecalis showed similar inactivation kinetics regardless of the added compound. Induction of oxidative stress in cells by micropollutants and higher exposure to additional ROS via (sono)photosensitization reactions are suggested as responsible for enhancing inactivation in natural water. The UV doses required for 90% degradation in the presence of bacteria (2.6-7.7 J/cm²) provide the simultaneous inactivation. Results show that the sono-photo-Fenton-like process could be a promising alternative for simultaneous water treatment and disinfection.

77.

Matafonova G., Batoev V. Dual-wavelength light radiation for synergistic water disinfection // Sci. Tot. Environ. – 2021. - https://doi.org/10.1016/j.scitotenv.2021.151233 (IF JCR - 7.963, Q1)

https://www.sciencedirect.com/science/article/pii/S0048969721063117?dgcid=author

Development of the narrow-band mercury-free light sources, such as light emitting diodes (LEDs) and excilamps, has stimulated research on inactivation of pathogenic microorganisms by dual-wavelength light radiation. To date, dual-wavelength light radiation has emerged as an advanced tool for enhancing microbial inactivation in water in view of potential synergistic effect. This is the first review that aims at elucidating its mechanisms under dual-wavelength light exposure and surveying a body of related literature in terms of yes-or-no synergy. We have proposed three key inactivation mechanisms, which function in the estimated spectrum ranges I (190-254 nm), II (250-320 nm) and III (300-405 nm) and provide a synergistic effect when combined. These mechanisms involve proteins damage and DNA repair suppression (I), direct and indirect DNA damage (II) and generation of reactive oxygen species (ROS) by endogenous photosensitizers (III), such as porphyrins and flavins. A synergy under dual-wavelength light irradiation simultaneously or sequentially occurs if coupling two wavelengths of different ranges (I + II, I + III, II + III) in order to trigger different inactivation mechanisms. Recent advances of dual-wavelength light strategy in photodynamic therapy could be applied for water disinfection. They bring opportunities for applying the sources of near-UV and visible radiation and making the disinfection processes more energy- and cost-effective. From this standpoint, the synergistically efficient dual-wavelength combinations II + III and the combinations within the extended to 700 nm range III (near-UV + VIS) appear to be promising for developing novel advanced oxidation processes for disinfection of real turbid waters.

78.

Maksanova, L., Bardakhanova, T., Lubsanova, N., Budaeva, D., & Tulokhonov, A. (2021). Assessment of losses to the local population due to restrictions on their ownership rights to land and property assets: The case of the Tunkinsky National Park, Russia. Plos one, 16(5), e0251383. DOI:10.1371/journal.pone.0251383. (IF JCR - 3.240, Q2)

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0251383

The impact of protected areas on local communities is the subject of intense discussions as part of the implementation of the global ecosystem protection agenda. Conflicts between the interests of environmental protection and the needs of socio-economic development become particularly acute when large areas of land are taken out of economic circulation as a result of organizing protected areas. In this case, there is an urgent need for detailed and reliable information about the social impacts of such land withdrawal on the well-being of the local population. An analysis of the methodological approaches widely presented in the literature, used to assess the social impact of protected areas, testifies to the insufficiency of completed and practically applicable methodological guidelines for the areas with significant restrictions for people who form part of the protected landscape. In this study, we understand the cost estimate of the social impact of national parks on the local population as a quantitative calculation of the losses due to restrictions on their ownership rights to land and property assets. The methodological approach consists in considering the category of losses as a sum total of the actual damage and lost profits. The assessment algorithm includes three stages: systematization of social impacts on citizens, development of indicators and data collection, and calculation of actual damage to the population and lost profits. The assessment is performed using the example of the Tunkinsky National Park located in the Tunkinsky municipal district of the Republic of Buryatia, a region of the Russian Federation, where there are 14 rural settlements with a population of more than 20,000 people. The results of the calculations show that the losses of the rural population due to legal restrictions on the registration of land dealings amount to 170.4 million USD. Taking into account the potential amount of administrative fines and the value of property subject to demolition, the losses amount to 239.2 million USD. It is more than an order of magnitude greater than the amount of own revenues of the Tunkinsky municipal district in 2011-2019. The results obtained demonstrate the real picture of the impact of restrictions on the rights of local people to land within the boundaries of national parks and are useful for developing measures to account for their interests and include protected areas in the socio-economic development of regions. The methodological approach developed by the authors can be used in other national parks, where it is necessary to optimize the policy of improving land use for local residents.

79.

Bilgaev, A., Dong, S., Li, F., Cheng, H., Tulohonov, A., Sadykova, E., & Mikheeva, A. (2021). Baikal Region (Russia) Development Prospects Based on the Green Economy Principles. Sustainability, 13(1), 157. DOI:10.3390/su13010157. (IF JCR - 3.251, Q2)

https://www.mdpi.com/2071-1050/13/1/157

The problems of preserving the natural environment are relevant for unique natural complexes of territories, such as the Baikal region (Russia). There are few studies devoted to forecasting the green economic development of the eco-socio-economic system of the Baikal region. The previous studies are mainly dedicated to the theory of forming the green economy in the Baikal region. This study aimed to forecast and determine future trends in the Baikal region’s eco-socio-economic development based on the green economy. The methodological approach to assess the Baikal region development prospects is based on determining the factors affecting the relationship between various eco-socio-economic components using multiple regression models. We constructed the forecast using the artificial neural networks method, and we assessed the possible impact of anthropogenic factors on the Baikal region’s eco-socio-economic system in the future. Based on the obtained forecast, we proposed a mechanism for regulating the green economy formation in the region. The regional governments of the Baikal region should perform the management function. This requires establishing a special interregional Green Development Fund to restructure incoming public funds by redistributing financial flows from contaminating brown to green industries and develop a state program for the Green Development of the Baikal region. The constructed forecast is informational support for decision making for the long-term development of the economy during the transition to the green economy, the development and justification of program activities, and the future’s main strategic priorities.

80.

Bilgaev, A., Sadykova, E., Li, F., Mikheeva, A., & Dong, S. (2021). Socio-Economic Factor Impact on the Republic of Buryatia (Russia) Green Economic Development Transition. International Journal of Environmental Research and Public Health, 18(20), 10984. DOI:10.3390/ijerph182010984 (IF JCR - 3.390, Q1)

https://www.mdpi.com/1660-4601/18/20/10984

Sustainable green development and environment preservation problems are relevant for unique territories with special economic activity modes, such as the Baikal natural territory. Within Russia, the Republic of Buryatia serves as the model territory for the Lake Baikal ecosystem preservation. Determining the socio-economic development impact on the region’s natural environment and resolving contradictions in transition to the green economic development requires the systematization of economic, social, and environmental processes of quantitative information based on the construction of composite indicators. We construct a composite indicator to assess the socio-economic factor’s impact on the Republic of Buryatia’s current economic state and to compare the current environmental subsystem state and the socio-economic parameters of Buryatia to the average Russian level. We use multiple regression models to determine relationships between various environmental-socio-economic parameters and identify the factors that most impact the environmental states (situations). The measures taken to preserve the unique ecosystem of Lake Baikal have an actual effect. This study shows, that according to the accepted scale, the environmental situation in the region can be characterized as a step towards the green economy transition. The proposed sustainable green development criteria and tools assessment system of the Republic may serve as the basis for forming information and analytical support for an effective economic policy.

81.

Prishchepov AV, Ponkina EV, Sun ZL, Bavorova M, Yekimovskaja OA. 2021. Revealing the intentions of farmers to recultivate abandoned farmland: A case study of the Buryat Republic in Russia // LAND USE POLICY, 2021.- 107: 105513. Doi: 10.1016/j.landusepol.2021.105513 (IF JCR – 5.398, Q1)

https://www.sciencedirect.com/science/article/pii/S0264837721002362?via%3Dihub

Despite the looming land scarcity suited for agricultural expansion, farmland abandonment is widespread globally. The recultivation of some abandoned farmlands could unlock the untapped agricultural potential. Yet, little is known about the determinants of recultivation. To better understand the behavioral intentions of farmers regarding the recultivation of abandoned lands, we concentrated on the Buryat Republic in Russia, where agricultural land abandonment is widespread and farmers with different ethnicities carry out diverse agricultural practices. We conducted 149 face-to-face interviews with the farmers in the Buryat Republic in 2018 and filled a structured questionnaire on farm's and farmers' socioeconomic characteristics, perceived corruption, and farmers' behavioral intentions regarding expected land use. We modeled the intention of recultivation with the Bayesian networks. The Bayesian networks analysis showed that perceived corruption was considered to be a barrier to recultivation. Our study also showed that non-Buryat ethnic and young farmers are more likely to recultivate abandoned land. Abandoned farmlands without or with a low degree of afforestation were preferred for recultivation. In sum, our study showed how behavioral aspects of political trust, the farm's and farmer's characteristics, in combination with regional and locational characteristics, may shape farmers' decisions on land use. The results provide an important ground to assess regional land-use policies, which should foster the recultivation of abandoned lands while preserving ecosystem services in the global hotspots of farmland abandonment, such as Russia