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Investigation into the operation of an autothermal two-section subbituminous coal fluidized bed gasifier

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International Journal of Coal Science & Technology 2023年第3期10卷 190-203页

作者： nikolay Abaimov Alexander Ryzhkov Alexey Dubinin Lu Ding Vladimir Tuponogov Sergey Alekseenko Ural Federal University EkaterinburgRussia 6200022 Institute of Clean Coal Technology East China University of Science and TechnologyShanghai 200237China Institute of Thermophysics Siberian BranchRussian Academy of SciencesNovosibirskRussia 630090

Using a newly developed experimental setup,the features and advantages of an autothermal single-casing atmospheric sub-bituminous coal fluidized bed air-blown gasifier,combining a combustion and gasification section,and mixing the dispersed phase(inert material,char)and heat exchange between them through an annular transfer device,have been *** increase the efficiency of the gasifier,an experimental-computational method was developed find the conditions for optimal operation,combining changing the annular flow's geometry and regulating the primary air for gasification.A simple and reliable multizone thermodynamic calculation model makes it possible to predict the composition of char and syngas in the gasification section with acceptable *** method confirmed that a two-section fluidized bed gasifier can provide efficient gasification of solid fuels and is suitable for use in small-scale cogeneration *** with a heating value of 3.6-4.5 mJ/m^(3)and CGE of 38.2%-42.3%was obtained in the experimental setup without optimizing the primary air flow *** optimization,the indicators increased to the heating value of syngas of 5.20-5.34 mJ/m^(3)and CGE of 42.5%-50.0%.With heat regeneration of 0.8,CGE increases to 70%.

关键词： Coal Syngas Gasification Bubbling fluidized bed Thermodynamics modeling

Laminar-Turbulent Bifurcation Scenario in 3D Rayleigh-Benard Convection Problem

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Open Journal of Fluid Dynamics 2016年第4期6卷 496-539页

作者： nikolay m. Evstigneev Laboratory of Chaotic Dynamical Systems Institute for System Analysis Russian Academy of Science Moscow Russia

We are considering two initial-boundary value problems for Rayleigh-Benard convection in Oberbeck-Boussinesq approximation for incompressible fluid in 3D-rectangular domain with 4:4:1 geometric ratio with periodicity in two directions and cubic domain with 1:1:1 ratio and zero velocity and temperature gradient boundary conditions. For this purpose, we use two numerical method: one is a Pseudo-Spectral-Galerkin method with trigonometric-Chebyshev polynomials and the other is finite element/volume method with WENO interpolation for advection term. Numerical methods are presented shortly and are benchmarked against known DNS data and against one another (for quasi-periodic domain problem). Then we perform stability analysis using analytical expression for main stationary solutions and eigenvalue numerical analysis by applying Implicitly Restarted Arnoldi (IRA) method. The IRA is used to perform linear stability analysis, find bifurcations of stationary points and analyze eigenvalues of monodromy matrices. Thus characteristic exponents of the system for time periodic solutions (limited cycles of various periods and resonance invariant tori) are computed. We show, numerically, the existence of multistable rotes to chaos through chaotic fractal attractors, full Feigenbaum-Sharkovski cascades and multidimensional torus attractors (Landau-Hopf scenario). The existence of these attractors is shown through analysis of phase subspaces projections, Poincare sections and eigenvalue analysis of numerically computed DNS data. These attractors burst into chaos with the increase of Rayleigh number either through resonance and phase-locking or through emergence of singular chaotic attractors.

关键词： Rayleigh-Benard Convection Direct Numerical Simulation Laminar-Turbulent Transition Bifurcations Nonlinear Dynamics Turbulence Chaos

New Physicochemical Treatment method of Poppy Seeds for Agriculture and Food Industries

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Plasma Science and Technology 2013年第9期15卷 935-938页

作者： Bozena ER Iveta GAJDOV michal ER'Y petr PATENKA Institute of Nanobiology and Structural Biology GCRC Academy of Sciences of the Czech RepublicDepartment of NanobiotechnologyNa Sadkach 7Ceske Budejovicecz-37005Czech Republic Department of Biology Faculty of EducationUniversity of South Bohemia in Ceske BudejoviceJeronymova 10Ceske Budejovicecz-37115Czech Republic Department of Applied Physics and Technics Faculty of EducationUniversity of South Bohemia in Ceske BudejoviceJeronymova 10Ceske Budejovicecz-37115Czech Republic

Poppy seeds （Papaver somniferum L.） are often attacked by various fungal dis- eases, and their field germination rate is low. The aim of this experiment was to increase the germination rate and growth of seedlings by modifying the poppy seeds using cold plasma dis- charge. The seeds were treated in a Plasonic AR-550-m under power of 500 W with argon gas flow of 50 mL/min, oxygen gas flow of 50 mL/min for different time durations in seconds （0, 180, 300, 600, 1800, 3000, 4200, and 5400）. The seed germination rate and growth of the seedlings were recorded. Cold plasma positively affected the seed germination rate for time exposure between 180～3000 s. Seedling acceleration on the sixth day of the experiment showed the highest values at exposure 180～600 s. Cold plasma seems to be a good physicochemical way to modify seeds without chemical agronomical application.

关键词： biotechnology early growth low-pressure discharge Papaver somniferum,seed modification seed germination

Searching for the brightest stars in galaxies outside the Local Group

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Research in Astronomy and Astrophysics 2021年第4期21卷 264-270页

作者： nikolay Tikhonov Olga Galazutdinova Olga Sholukhova Antoniya Valcheva Petko Nedialkov Olga merkulova Special Astrophysical Observatory Nizhnij ArkhyzKarachai-Cherkessian RepublicRussia 369167 Department of Astronomy Sofia University1504 Sofia15 Tsar Osvoboditel Blvd.SofiaBulgaria Astronomical Institute St.Petersburg State UniversityUniversitetskii pr.28St.Petersburg198504 Russia

This paper introduces a technique for searching for bright massive stars in galaxies beyond the Local *** search for massive stars,we processed the results of stellar photometry from the Hubble Space Telescope(HST)images using the DAOPHOT and DOLPHOT *** results of such searches are demonstrated with examples of the galaxies DDO 68,m94 and NGC *** the galaxy DDO 68,the LBV star changes its brightness,and massive stars in m94 can be identified by excess in the Ha *** the galaxy NGC 1672,we measure the distance for the first time by the TRGB method,which enabled determining the luminosities of the brightest stars,likely hypergiants,in the young star formation *** far,we have performed stellar photometry on HST images of 320 northern sky galaxies located at a distance less than 12 *** allowed us to identify 53 galaxies with probable *** photometric and spectral observations of these galaxies are planned to search for massive stars.

关键词： stars:massive stars:variables:LBV galaxies:individual:m94 DDO 68 NGC 1672

Numerical Simulation of Airfoil Vibrations Induced by Turbulent Flow

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Communications in Computational Physics 2015年第1期17卷 146-188页

作者： miloslav Feistauer Jaromır Horacek petr Svacek Charles University in Prague Faculty of Mathematics and PhysicsSokolovska 8318675 Praha 8Czech Republic Institute of Thermomechanics Academy of Sciences of the Czech RepublicDolejskova 518200 Praha 8Czech Republic Czech Technical University Prague Faculty of Mechanical EngineeringKarlovo nam.1312135 Praha 2Czech Republic

The subject of the paper is the numerical simulation of the interaction of two-dimensional incompressible viscous flow and a vibrating airfoil with large *** airfoil with three degrees of freedom performs rotation around an elastic axis,oscillations in the vertical direction and rotation of a *** numerical simulation consists of the finite element solution of the Reynolds averaged Navier-Stokes equations combined with Spalart-Allmaras or k−ω turbulence models,coupled with a system of nonlinear ordinary differential equations describing the airfoil motion with consideration of large *** time-dependent computational domain and approximation on a moving grid are treated by the Arbitrary Lagrangian-Eulerian formulation of the flow *** to large values of the involved Reynolds numbers an application of a suitable stabilization of the finite element discretization is *** developed method is used for the computation of flow-induced oscillations of the airfoil near the flutter instability,when the displacements of the airfoil are large,up to±40 degrees in *** paper contains the comparison of the numerical results obtained by both turbulence models.

关键词： Fluid-structure interaction flow induced vibrations Reynolds averaged NavierStokes equations turbulence models finite element method coupling algorithm

Influence of frost weathering on the recession of surfaces of technogenic landforms in Yakutia

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Research in Cold and Arid Regions 2019年第4期11卷 257-266页

作者： Andrey E.melnikov nikolay N.Grib melnikov Permafrost Institute of the Siberian Branch of the Russian Academy of Sciences Yakutsk 677010Russia Technical Institute(branch)of m.K.Ammosov North-eastern Federal University Neryungri 678960Russia

The article assesses the influence of permafrost weathering on the rate of destruction of technogenic land forms,as exhibit ed on as illustrated by the railway embankment of the Amur Yakut mainline in the Sakha Republic(Yakutia).Studies were carried out on a railway section more than 375 km *** subsidence rate of the embankment slopes and structur al excavations was determined using laboratory methods that simulate various mechanisms of temperature(with a transi tion through 0℃)impact on *** the first time,a quantitative assessment of the influence of cryogenic weathering on the stability of the railway in the region belonging to the northern building climatic zone is *** the territory un der consideration,embankment rocks were experimentally determined to undergo more than 100 freezing and thawing cy cles during a *** the existing climatic conditions,cryogenic weathering actively affects the embankment of the railway to a depth of 30 *** of the embankment deformations detected during field observations are due to defects in the integrity of this particular *** size of the disintegrating layer of particular types of rock comprising the rail way embankment has been established as reaching 10 cm per *** 5 years following the formation of embankments comprising the upper structure of the railroad tracks,the physical and mechanical properties of rocks,which initially had a tensile strength for uniaxial compression in the range of 40 70 mPa,were reduced by more than 50%.According to the authors,the establishment of regional cryohypergenesis features is universal in nature and can be applied to solving a wide range of tasks related to the assessment and prediction of the degree of cryogenic transformation of rocks having different structural properties.

关键词： cryogenic weathering embankment railway subsidence rate Republic of Sakha Yakutia

mo掺杂CeO_(2)催化剂上甲烷的无氧偶联:表面和气相过程

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Chinese Journal of Catalysis 2023年第6期49卷 68-80页

作者：张昊苏亚琼 nikolay Kosinov Emiel J.m.Hensen 埃因霍温理工大学化学工程与化学系无机材料与催化实验室荷兰埃因霍温西安交通大学化学学院储能材料与设备教育部工程研究中心国家储能技术产教融合创新平台(中心)陕西西安710049

甲烷无氧偶联是一种很有前景的甲烷转化利用的增值途径.由于高温条件下催化剂表面反应与气相自由基反应共存且均对产物分布具有重要影响,因而很难深入理解该反应的机理.本文采用火焰喷雾热解方法制备了一系列具有高度分散mo位点的mo掺杂... 详细信息

甲烷无氧偶联是一种很有前景的甲烷转化利用的增值途径.由于高温条件下催化剂表面反应与气相自由基反应共存且均对产物分布具有重要影响,因而很难深入理解该反应的机理.本文采用火焰喷雾热解方法制备了一系列具有高度分散mo位点的mo掺杂的CeO_(2)样品,并用于催化甲烷无氧偶联反应.结果表明,在气相产物中,附加值较高的C2烃产物(乙烷和乙烯)的选择性可达98%.反应过程中催化剂中高度分散的mo-oxo物种被还原并转化为mo(oxy-)碳化物物种,它是甲烷活化的活性位点.通过改变反应器内气相部分(即无催化剂部分)的体积,研究了气相反应对于产物分布的贡献.乙烷是甲烷无氧偶联的初级产物,部分乙烯和大部分苯是通过气相化学形成的.综上,本文为甲烷无氧偶联高效催化剂的设计提供了参考,并明确了减少反应器中自由体积以限制二次气相反应的重要性.

关键词：甲烷无氧偶联 CeO_(2) mo 活性位

On the Question of Defining the Association Constants by the method of Fluorescence Quenching

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American Journal of Analytical Chemistry 2014年第16期5卷 1065-1068页

作者： nikolay L. Lavrik nikolay m. Bazhin Voevodsky Institute of Chemical Kinetics and Combustion SB RAS Novosibirsk Russian Federation

A study is made on the previously ignored problem of the dependence of a static fluorescence quenching Stern-Volmer constant?Ksv on the initial concentration of [F]0 fluorophore F. This correlation is shown to exist. ... 详细信息

关键词： Fluorescence Quenching Association Constants Stern-Volmer Constant

Influence of environmental predispositions on temperate mountain forest damage at different spatial scales during alternating drought and flood periods:case study in Hruby Jeseník mts.(Czech Republic)

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Journal of mountain Science 2022年第7期19卷 1931-1944页

作者： Pavel SAmEC Romana KUDELKOVA petr LUKES Ales KUCERA Pavel CUDLIN Global Change Research Institute CAS Bělidla 986/4aBrnoCZ-60300Czech Republic Department of Geology and Soil Science Faculty of Forestry and Wood TechnologyMendel University in BrnoZemědělská3BRNOCZ-61300Czech Republic Department of Geoinformatics Faculty of SciencePalacky University Olomouc17.listopadu 50OlomoucCZ-77900Czech Republic

mountain forests are more prone to environmental predispositions(EPs)than submountain *** remote sensing of mountain forests enables instantaneous damage mapping,the investigation of the causes requires field ***,a local field or regionally modeled environmental characteristics influence remote data evaluation *** study focused on the evaluation of EPs effects damaging mountain forests between various spatial resolutions during environmental *** evaluation was divided into managed and natural forests in the Hruby Jeseník mts.(Czech Republic;240-1491 m a.s.l.;50.082°N,17.231°E).Damage was assessed through the discrimination analysis of the normalised difference vegetation index(NDVI)by mODIS VI during alternating drought and flood periods *** local environmental influence was assessed using the discrimination function(DF)separability of forest damage in the training *** regional influence was assessed through map algebra estimated via the DF and a forest decline spatial model based on EPs from differences between risk growth conditions and biomass fuzzy ***,EPs and soil influenced forest NDVI at different *** management afflicted the NDVI more than the *** EPs afflicted the NDVI more than the soil *** winters and droughts had a greater influence on the NDVI than the flood events,with the winter of 2005/2006 inverting the DF direction,and the 2003 drought increasing differences in managed forest biomass and decreasing differences in natural forest *** than 50% of declining managed forests in the training sets occurred on Leptosols,Podzols and *** a regional scale,the soil influence was eliminated by multiple *** EPs influenced 96% of natural forest and 65% of managed forest,though managed forest damage was more *** mountain forest NDVI decline was dependent on both management and risk predispositions.

关键词： mountain environment Forest damage types Canopy density Soil group Norway spruce(Picea abies)