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Growth rate of CO_(2) hydrate film on water-oil and water-gaseous CO_(2) interface

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Chinese Journal of Chemical Engineering 2023年第4期56卷 266-272页

作者： Tatyana P.Adamova sergey s.skiba Andrey Yu.Manakov sergey Y.Misyura Kutateladze Institute of Thermophysics sB RAs Lavrentiev Ave.1Novosibirsk 630090Russian Federation

It is known that injection of carbon dioxide into the petroleum reservoir(CO_(2) flooding) is one of the effective methods for enhanced oil recovery. CO_(2) flooding may be complicated by formation of CO_(2) hydrate plugs. It makes topical investigation of CO_(2) hydrate formation in the system gaseous CO_(2)-oil-water. In this work, the growth rates of carbon dioxide hydrate films at the water-oil as well as the water-gas interface are studied in the pressure range of 2.30-3.04 MPa and at temperatures between -5.4 and 5.0℃. It is found that the growth rate for the water-oil interface is 3.5 times lower than that for the water-gas interface with carbon dioxide. It is hypothesised that the observed decrease in the growth rate is related to the mechanical resistance of the oil components adsorbed on the interface to the growth of the hydrate film. The growth rate of the film has been shown to depend on the experimental procedure,most likely due to the different initial concentrations of carbon dioxide in the aqueous solutions.

关键词： Gas hydrate Oil Carbon dioxide Growth rate Hydrate film

Mathematical Modeling of Heat Transfer Processes of Coal Waste Combustion in a Chamber of Automated Energy Generating Complex

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Journal of Thermal science 2013年第2期22卷 174-179页

作者： sergey P. Mochalov sergey N. Kalashnikov Pavel s. Mochalov Guolin song Guoyi Tang siberian state Industrial University Advanced Materials Institute Graduate School at ShenzhenTsinghua University

The automated energy generating complex allows obtaining heat energy from waste coal-water slurry fuel （WCF） that is a mixture of fine coal particles from coal enrichment wastes with water. The mixture is blown into the swirl chamber under the pressure through the special sprayers. The received heat energy is used in different ways. One of the important issues is to estimate the heat losses through the walls of this chamber. In this paper we solved the boundary problem of mathematical physics to estimate the temperature fields in the walls of the swirl chamber. The obtained solution allows us to estimate the heat losses through the waUs of the swid chamber. The task of the mathematical physics has been solved by a numerical finite-difference method. The method for solving this prob- lem can be used in the calculation of temperature fields and evaluation of heat losses in other thermal power units.

关键词： heat transfer heat conduction equation boundary conditions the heat transfer coefficient tempera-ture distribution.

some solutions of the nonhomogeneous Bagley–Torvik equation

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International Journal of Modeling, simulation, and scientific Computing 2019年第1期10卷 17-22页

作者： Temirkhan s.Aleroev sergey Erokhin Applied Mathematics Department Moscow state University of Civil Engineering Moscow 26 Yaroslavskoe shosse129337Russian Federation

In this study,nonhomogeneous differential equation of the second order is considered,which contains fractional derivative(Bagley-Torvik equation),where the derivative order ranges within 1 and *** equation is applied in mechanics of oscillation *** study the equation,we use the Laplace transform,which allows us to obtain an image of the solution in an explicit *** typical kinds of functions of the right-hand side of the equation are *** solutions are constructed for each of *** solutions obtained are compared with experimental information on polymer concrete *** comparison allows for the conclusion about the adequacy of the numerical and analytical solutions to the nonhomogeneous Bagley-Torvik equation.

关键词： Fractional derivative Bagley-Torvik equation viscoelasticity Laplace transform

BER Performance of Finite in Time Optimal FTN signals for the Viterbi Algorithm

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Journal of Electronic science and Technology 2020年第1期18卷 42-51页

作者： sergey B.Makarov Ilya I.Lavrenyuk Anna s.Ovsyannikova sergey V.Zavjalov Higher school of Applied Physics and space Technologies Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251

In this article, we consider the faster than Nyquist(FTN) technology in aspects of the application of the Viterbi algorithm(VA). Finite in time optimal FTN signals are used to provide a symbol rate higher than the "Nyquist barrier" without any encoding. These signals are obtained as the solutions of the corresponding optimization problem. Optimal signals are characterized by intersymbol interference(IsI). This fact leads to significant bit error rate(BER) performance degradation for "classical" forms of signals. However, IsI can be controlled by the restriction of the optimization problem. so we can use optimal signals in conditions of increased duration and an increased symbol rate without significant energy losses. The additional symbol rate increase leads to the increase of the reception algorithm complexity. We consider the application of VA for optimal FTN signals reception. The application of VA for receiving optimal FTN signals with increased duration provides close to the potential performance of BER,while the symbol rate is twice above the Nyquist limit.

关键词： Bit error rate(BER)performance faster than Nyquist(FTN) Nyquist limit optimal signals Viterbi algorithm(VA)

A review of ferroelectric materials for high power devices

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Journal of Materiomics 2022年第4期8卷 739-752页

作者： sergey I.shkuratov Christopher s.Lynch Loki Incorporated 1334 Royal RoadNorwoodMO65717USA Bourns College of Engineering University of California at RiversideCA92521USA

Compact autonomous ultrahigh power density energy storage and power generation devices that exploitthe spontaneous polarization of ferroelectric materials are capable of producing hundreds of kilovoltvoltages,multi-kiloampere currents,and megawatt power levels for brief interval of *** storagelife of these devices is four orders of magnitude longer than that for electrochemical batteries andelectrochemical *** is an up to date survey of ferroelectric materials used for these highpower *** types of ferroelectric ceramics possess the ability to be depolarized under adia-batic compression and can be successfully used for high power *** addition to bulk ferro-electric ceramics,multilayer ferroelectric films are very efficient materials for high power *** importance is the ability of relaxor ferroelectric single crystals to produce significantly higherelectric charge density and energy density than ceramics,making them promising materials for highpower *** provided is a brief survey of recent developments of ferroelectric materials forhigh energy density and power density dielectric *** ceramics have been developed,including antiferroelectric and relaxor antiferroelectric solid solutions,providing high energy densityand efficiency simultaneously.

关键词： Energy storage Ferroelectric Antiferroelectric Relaxor High power density

Analytical solution of axisymmetric contact problem about indentation of a circular indenter into a soft functionally graded elastic layer

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Acta Mechanica sinica 2013年第2期29卷 196-201页

作者： sergey Volkov sergey Aizikovich Yue-sheng Wang Igor Fedotov Research and Education Center "Materials" Don State Technical University south Federal University Research Institute of Mechanics and Applied Mathematics Institute of Engineering Mechanics Beijing Jiaotong University Department of Mathematical Technology Tshwane University of Technology

The paper addresses a contact problem of the theory of elasticity,i.e.,the penetration of a circular indenter with a flat base into a soft functionally graded elastic *** elastic properties of a functionally graded layer arbitrarily vary with depth,and the foundation is assumed to be elastic,yet much harder than a *** analytical solution is constructed,and it is shown that the solutions are asymptotically exact both for large and small values of characteristic dimensionless geometrical parameter of the *** examples are analyzed for the cases of monotonic and nonmonotonic variations of elastic *** results for the case of homogeneous layer are compared with the results for nondeformable foundation.

关键词： Contact problems·Indentation·Functionally graded layer

Reactivation of hepatitis B virus infection – an important aspect of multifaceted problem

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World Journal of Gastroenterology 2024年第26期30卷 3193-3197页

作者： sergey Morozov sergey Batskikh Department of Gastroenterology Hepatology and NutritionFederal Research Center of NutritionBiotechnology and Food SafetyMoscow 115446Russia Department of Hepatology Moscow Clinical Scientific Center N.A.A.S.LoginovMoscow 111123Russia

In this editorial we comment on the article published in the recent issue of the W orld Journal of *** focus specifically on the problem of occult hepatitis B virus(HBV)infection,that is a result of previous hepatitis B(PHB)and a source for reactivation of *** prevalence of PHB is underestimated due to the lack of population testing ***,this condition not only com-plicate anticancer treatment,but may be responsible for the development of other diseases,like cancer or autoimmune *** we unveil possible mecha-nisms responsible for realization of these processes and suggest practical approa-ches for diagnosis and treatment.

关键词： Occult hepatitis B virus infection Hepatitis B virus reactivation Previous hepatitis B Cancer Autoimmune disorders

A Note on Transition Kernels for the Most UnfavourableMixed strategies of the Market

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Journal of the Operations Research society of China 2024年第1期12卷 35-50页

作者： sergey N.smirnov Faculty of Computational Mathematics and Cybernetics Lomonosov Moscow State UniversityMoscowRussian Federation 119991

We consider a deterministic model of market evolution with trading constraints andapply a game-theoretic approach to the superhedging *** obtain sufﬁcientconditions for the game equilibrium and prove under these conditions the existenceof a Borel-measurable transition kernel describing dependence on price prehistory ofthe most unfavourable mixed strategy of the market.

关键词： superhedging Guaranteed deterministic approach Optimal mixedstrategies of the market Borel-measurable transition kernel Game equilibrium

structural stability of the Financial Market Model: Continuity of superhedging Price and Model Approximation

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Journal of the Operations Research society of China 2024年第1期12卷 215-241页

作者： sergey N.smirnov Faculty of Computational Mathematics and Cybernetics Lomonosov Moscow State UniversityMoscow119991Russian Federation

The present paper continues the topic of our recent paper in the same journal,aiming to show the role of structural stability in financial *** the context of financial market modeling,structural stability means that a specific“no-arbitrage”property is unaffected by small(with respect to the Pompeiu–Hausdorff metric)perturbations of the model’s *** formulate,based on our economic interpretation,a new requirement concerning“no arbitrage”properties,which we call the“uncertainty principle”.This principle in the case of no-trading constraints is equivalent to structural *** demonstrate that structural stability is essential for a correct model approximation(which is used in our numerical method for superhedging price computation).We also show that structural stability is important for the continuity of superhedging prices and discuss the sufficient conditions for this continuity.

关键词： Uncertainty structural stability No arbitrage Continuity of superhedging price Compact-valued multifunction Financial market model approximation Trading constraints