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Decomposition of carbon dioxide hydrate in the samples of natural coal with different degrees of metamorphism

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Chinese Journal of Chemical Engineering 2020年第2期28卷 492-501页

作者： Vyacheslav G. Smirnov Valeriy V. Dyrdin andrey yu. manakov Zinfer R. Ismagilov Kuzbass State Technical University Vesennaya str.28Kemerovo 650000Russian Federation Nikolaev Institute of Inorganic Chemistry SB RAS Ac.Lavrentiev ave.3Novosibirsk 630090Russian Federation Novosibirsk State University Pirogov Str.2Novosibirsk 630090Russian Federation Institute of Coal Chemistry and Material Science SB RAS Sovetsky ave.18Kemerovo 650000Russian Federation

Methane and carbon dioxide hydrates are one of the possible forms in which these gases exist in natural coal(for more detailed discussion see Refs [1,2]). In this work, the decomposition of carbon dioxide hydrate in five samples of natural coal differing from each other in metamorphism degree was investigated experimentally. Carbon dioxide hydrate dispersed in coals was synthesized from water adsorbed in these coals. During a linear temperature rise in an autoclave with the coal + hydrate sample the hydrate decomposition manifests itself as a step of increase in gas pressure, accompanied by a decrease/stabilization of the temperature of coal sample. The dependencies of the amount of hydrate formed on initial coal humidity and on gas pressure during hydrate formation were studied. It was demonstrated that each coal sample is characterized by its own humidity threshold below which hydrate formation in natural coal is impossible. With an increase in gas pressure, the amount of water transformed into hydrate increases. For the studied coal samples, the decomposition of carbon dioxide hydrates proceeds within a definite temperature and pressure range, and this range is close to the curve of phase equilibrium for bulk hydrate.

关键词： Gas hydrate Carbon dioxide Coal Coal rank Phase transformation Coal bed gas

Synergistic effect of combination of surfactant and oxide powder on enhancement of gas hydrates nucleation

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Journal of Energy Chemistry 2017年第4期26卷 808-814页

作者： Anatoliy N.Nesterov Aleksey M.Reshetnikov andrey yu.manakov Tatyana P.Adamova Institute of Earth’s Cryosphere SB RAS Malygina str.86Tyumen 625026Russian Federation Tyumen State University Volodarskogo Str.6Tyumen 625003Russian Federation Tyumen Industrial University Volodarskogo Str.38Tyumen 625000Russian Federation Nikolaev Institute of Inorganic Chemistry SB RAS Lavrentieva ave.3Novosibirsk 630090Russian Federation Novosibirsk State University Pirogova Str.2Novosibirsk 630090Russian Federation

In the present work we studied the induction periods of hydrate formation of natural gas in pure water, aqueous solutions of surfactants, and in the presence of surfactant together with aluminum oxide nanopowder, the activity of which as hydrate formation inducer was studied previously. Sodium dodecyl sulfate（SDS） or neonol AF-9-12 were used as the surfactants. It was demonstrated that the addition of either surfactants or aluminum oxide powder under our experimental conditions causes a decrease in the induction period of hydrate formation from;05 min for pure water to 30–35 min for water with additives. In the case of the simultaneous presence of surfactants and aluminum oxide powder in the system, induction period decreased to;0 min. So, the synergistic effect of the combination of surfactant and oxide powder on gas hydrate nucleation was demonstrated. Possible reasons of this effect have been discussed.

关键词： Gas hydrate Hydrate formation Nucleation Induction period Surfactant Nanopowder

Nucleation of methane hydrate and ice in emulsions of water in crude oils and decane under non-isothermal conditions

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Chinese Journal of Chemical Engineering 2019年第3期27卷 668-676页

作者： andrey S. Stoporev Lidiya I. Svarovskaya Larisa A. Strelets Lubov’ K. Altunina Galina V. Villevald Tamara D. Karpova Tatyana V. Rodionova andrey yu. manakov Nikolaev Institute of Inorganic Chemistry SB RAS Novosibirsk State University Institute of Petroleum Chemistry

Achievable supercooling for the formation of methane hydrate from water emulsions was studied in seven different crude oils and in decane. The experiments were performed under constant rate cooling from + 20 to-15 °C and a pressure of methane of 12 MPa. It was demonstrated that the shapes and positions of the resulting survival curves depend on the density, viscosity and dispersive power of oil samples used in the experiments, as well as on the degree of oil oxidation. In addition, results of the experiments on ice freezing under the same emulsions are presented. The results obtained in the work allowed us to discuss the possibility and features of primary and secondary nucleation of the hydrate and ice in the systems under consideration.

关键词： Methane hydrate Crude oil Oil dispersive system Nucleation

Dissociation behavior of “dry water” C_3H_8 hydrate below ice point:Effect of phase state of unreacted residual water on a mechanism of gas hydrates dissociation

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Journal of Energy Chemistry 2015年第3期24卷 309-314页

作者： andrey O Drachuk Vladimir P Melnikov Nadezhda S Molokitina Anatoliy N Nesterov Lev S Podenko Aleksey M Reshetnikov andrey yu.manakov Institute of Earth Cryosphere SB RAS625026Malygin str.86TyumenRussian Federation Tyumen State Oil and Gas University 625000Volodarsky str.38TyumenRussian Federation Nikolaev Institute of Inorganic Chemistry SB RAS630090Lavrentiev av.3NovosibirskRussian Federation

The results on a dissociation behavior of propane hydrates prepared from ＂dry water＂ and contained unreacted residual water in the form of ice inclusions or supercooled liquid water（water solution of gas） were presented for temperatures below 273 *** temperature ramping or pressure release method was used for the dissociation of propane hydrate *** was found that the mechanism of gas hydrate dissociation at temperatures below 273 K depended on the phase state of unreacted water in the hydrate *** hydrates dissociated into ice and gas if the ice inclusions were in the hydrate *** samples of propane hydrates with inclusions of unreacted supercooled water only（without ice inclusions） dissociated into supercooled water and gas below the pressure of the supercooled water-hydrate-gas metastable equilibrium.

关键词： gas hydrates dry water supercooled liquid water ice hydrate dissociation

Study of variable stars associated with maser sources: G025.65+1.05

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Research in Astronomy and Astrophysics 2019年第3期19卷 47-52页

作者： andrey M.Sobolev Anastasia P.Bisyarina Stanislav yu.Gorda andrey M.Tatarnikov Astronomical Observatory of the Ural Federal University Sternberg Astronomical Institute of Moscow State University

We report variation of K-band infrared(IR) emission in the vicinity of the G025.65+1.05 water and methanol maser source. New observational data were obtained with the 2.5 m telescope at the Caucasian Mountain Observatory(CMO) of Moscow State University on 2017–09–21 during a strong water maser flare. We found that the IR source situated close to the maser position had decreased brightness in comparison to archive data. This source is associated with a massive young stellar object(MYSO) corresponding to the compact IR source IRAS 18316–0602(RAFGL 7009 S). A similar decrease in K-brightness of the IR source close to the maser position was observed in March 2011 when the water maser experienced a period of increased activity. The dips in MYSO brightness can be related to the maser flare phases. Maser flares that are concurrent with dips in the IR emission can be explained if the lower IR radiation field enables a more efficient sink for the pumping cycle by allowing IR photons to escape the maser region.

关键词： techniques photometric-infrared stars-masers

Acoustic emission characterization of sliding wear under condition of direct and inverse transformations in lowtemperature degradation aged Y-TZP and Y-TZP-Al_2O_3

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Friction 2018年第3期6卷 323-340页

作者： Nikolai L SAVCHENKO andrey V FILIPPOV Sergei yu TARASOV andrey I DMITRIEV Evgeny V SHILKO Aleksandr S GRIGORIEV Institute of Strength Physics and Materials Science SB RAS National Research Tomsk Polytechnic University National Research Tomsk State University

In this research, results of the investigation of the sliding friction and wear of yttria-stabilized tetragonal zirconia polycrystalline(Y-TZP) and Y-TZP-Al_2O_3 samples preliminarily subjected to low-temperature degradation are reported. The investigation was carried out using a pin-on-disk tribometer with simultaneous recording of acoustic emission(AE) and vibration acceleration. The sliding wear process was found to be determined by dynamic direct and inverse Y-TZP transformations detected by monoclinic and tetragonal X-ray diffraction peak ratios. The AE signals generated under direct and inverse transformations can be used to characterize wear and friction mechanisms as well as direct and inversed sliding-induced phase transformations. The AE signal energy grows with the friction coefficient and the inverse transformation degree. Reduction of the AE signal energy indicates establishing the mild wear stage caused by effective stress-induced direct martensitic transformation. The AE signal median frequency increases in the case of lower friction. Numerical studies of wear subsurface fracture under conditions of stress-induced martensitic transformation were used to elucidate the role played by the phase transformation in Y-TZP and Y-TZP-Al_2O_3. Martensitic transformation in Y-TZP was described with use of the non-associated dilatant plasticity model. Simulation results particularly show that increase in the value of dilatancy coefficient from 0 to 0.2 is accompanied by 25%-30% reduce in characteristic length and penetration depth of sliding-induced subsurface cracks. As shown the AE may be an effective tool for in-situ monitoring the subsurface wear of materials experiencing both direct and inverse transformations.

关键词： zirconia transformation toughening low-temperature degradation friction acoustic emission numerical modeling movable cellular automata method

Catagenetic type of manganese ores:REE and isotope(δ^(13)C,δ^(18)O)geochemical features(on the example of the Usa deposit,Russia)

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Acta Geochimica 2024年第6期43卷 1133-1152页

作者： Vladimir N.Kuleshov andrey yu.Bychkov Irina yu.Nikolaeva Maria E.Tarnopolskaia Geological Institute Russian Academy of SciencesPyzhevskii Per.7119017 MoscowRussia Lomonosov Moscow State University Leninskie Gory1119899 MoscowRussia

Chemical(REE and major elements)and isotope(δ^(13)C,δ^(18)O)composition of carbonate manganese ores and manganese-bearing carbonates of the Usa deposit(Siberia,Russia)were *** data on the composition of REE exhibit both the distinct negative(Ce/Ce*_(PAAS)1)cerium anomalies and the positive Eu-anomaly(Eu/Eu*_(PAAS)>1).Negative Eu-anomalies are not *** contents of Mn,Fe,REE,and Ce-anomalies show a positive correlation with each ***-anomalies and the amount of manganese and REE in relation to the carbon isotope composition(δ^(13)C)show a negative relationship and indicate that oxidized carbon of organic matter played an important role in the concentration of manganese and REE in manganese *** chemical and isotope composition of examined rocks indicates on secondary formation of *** major phases and sources are distinguished in the ore-forming process characterized by diff erent chemical(REE and ore elements)and isotope composition:(i)highgrade manganese ores(with high contents of REE and light carbon isotope composition)and(ii)low-grade manganese ores(with low contents of REE and heavy carbon isotope composition).

关键词： Manganese ore REE Isotope composition Catagenesis Cambrian Siberia

Rare earth elements(REE)and isotope composition(δ^(13)C andδ^(18)O)of manganese ores of Chiatura deposit(Georgia):features of ore formation and genesis

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Acta Geochimica 2023年第4期42卷 779-801页

作者： Vladimir N.Kuleshov andrey yu.Bychkov Irina yu.Nikolaeva Maria E.Tarnopolskaya Geological Institute Russian Academy of SciencesPyzhevskii Per.7MoscowRussia 119017 Lomonosov Moscow State University Leninskie Gory1MoscowRussia 119899

The rare earth elements(REE)geochemistry and the isotope(δ^(13)C,δ^(18)O)composition of manganese ores of the Chiatura(Georgia)deposit were *** of the major features of all types of manganese ores is negative cerium(Ce/Ce*_(PAAS))anomaly and the absence of europium(Eu/Eu*_(PAAS))*** oolitic manganese ores were formed in oxic shallow marine *** content and distribution of REEs(in particular Ce and Eu)in these ores are connected mainly with ferrous *** performed C-and O-isotope research in Mn-carbonates(oolitic and massive)has indicated that carbonate ores were formed by the participation of isotopic ally light CO_(2)which is a result of the oxidation of organic matter in the sediment strata by reducing environments of early diagenesis(and,partially,catagenesis)*** negative cerium anomalies in the studied carbonate ores reflect the specific REE patterns in pore waters of sediments of earlier isdiagenesis zone of the Oligocene Chiatura's *** deficiency of cerium in this zone remains debatable and requires further *** of manganese carbonates took place multistage by the input of incisional solutions of different chemistry into sea bottom waters and *** absence of europium anomaly indicates about lack of hydrothermal solution input.

关键词： REE Cerium anomaly Carbon and oxygen isotope geochemistry Oxide and carbonate manganese ores Chiatura deposit

Regularities in the E. coli promoters composition in connection with the DNA strands interaction and promoter activity

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第12期7卷 969-973页

作者： BEREZHNOY andrey yu SHCKORBATOV yuriy G. HISANORI Kiryu National Scientific Center Kharkov Physical-Technical Institute Kharkov 61108 Ukraine Institute of Biology Kharkov National University Maidan Svobody 4 Kharkov 61077 Ukraine Computational Biology Research Center National Institute of Advanced Industrial Science and Technology Koto-ku Tokyo 135-0064 Japan)

The energy of interaction between DNA strands in promoters is of great functional importance. Visualization of the energy of DNA strands distribution in promoter sequences was achieved. The separation of promoters in groups by their energetic properties enables evaluation of the dependence of promoter strength on the energetic properties. The analysis of groups (clusters) of promoters distributed by the energy of DNA strands interaction in ?55, ?35, ?10 and +6 sequences indicates their connection with the transcriptional activity.

关键词： DNA sequence Promoter strength DNA chains interaction energy DNA sequences classification