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Nonlinear convection in a non-Darcy porous medium

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Applied Mathematics and Mechanics(English Edition) 2010年第5期31卷 565-574页

作者： M. k. PARTHA Department of Mathematics Malnad College of Engineering

In this paper, the natural convection in a non-Darcy porous medium is studied using a temperature-concentration-dependent density relation. The effect of the two parameters responsible for the nonlinear convection is analyzed for different values of the inertial parameter, dispersion parameters, Rayleigh number, Lewis number, Soret number, and Dufour number. In the aiding buoyancy, the tangential velocity increases steeply with an increase in the nonlinear temperature parameter and the nonlinear concentration parameter when the inertial effect is zero. However, when the inertial effect is non-zero, the effect of the nonlinear temperature parameter and the nonlinear concentration parameter on the tangential velocity is marginal. The concentration distribution varies appreciably and spreads in different ranges for different values of the double dispersion parameters, the inertial effect parameter, and also for the parameters which control the nonlinear temperature and the nonlinear concentration. Heat and mass transfer varies extensively with an increase in the nonlinear temperature parameter and the nonlinear concentration parameter depending on Dacry and non-Darcy porous media. The variation in heat and mass transfer when all the effects, i.e., the inertial effect, double dispersion ef- fects, and Soret and Dufour effects, are simultaneously zero and non-zero. The combined effects of the nonlinear temperature parameter, the nonlinear concentration parameter and buoyancy are analyzed. The effect of the nonlinear temperature parameter and the nonlinear concentration parameter and also the cross diffusion effects on heat and mass transfer are observed to be more in Darcy porous media compared with those in non- Darcy porous media. In the opposing buoyancy, the effect of the temperature parameter is to increase the heat and mass transfer rate, whereas that of the concentration parameter is to decrease.

关键词： non-Darcy porous medium natural convection double dispersion

Hydrogenic Donor in a Spherical Quantum Dot with Different Confinements

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Chinese Physics Letters 2009年第8期26卷 309-312页

作者： A. John Peter k. Navaneethak.ishnan Govt. Arts College Melur-625 106 Madurad India Madurai k.maraj-University Madurai-625 021 India

Binding energies of a hydrogenic donor in a spherical GaAs quantum dot surrounded by Ga1-xA4xAs matrix are calculated. The results are presented for realistie barrier heights corresponding to different values of x （x 〈 0.4）. The calculations are performed under two different conditions：（i） a spherical dot with square well confinement and （ii） a dot with parabolic potential well confinement. The results show that （i） the donor ionization energies are always higher under parabolic confinement as compared to a dot of the same radius under square well confinement and （ii） the oscillator strengths coupling ground state with excited states are two orders larger under parabolic confinement. Our results are in agreement with the results of other researchers.

关键词： No English k.yword

Realizing high-performance ternary organic solar cell with thick.active layer via incorporating a liquid crystalline small molecule as a third component

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Science China Chemistry 2017年第4期60卷 435-436页

作者： Alex k.-Y. Jen Department of Materials Science and Engineering University of Washington Seattle WA 98195 USA Department of Physics & Materials Science City University of Hong Kong Kowloon 999077 Hong Kong

In the past two decades, organic solar cells （OSCs） have at- tracted significant attention owing to their merits of achieving light-weight, flexible, low-cost devices [1,2]. Ternary OSC as an efficient way to improve the power conversion efficiencies （PCEs） of OSCs has inspired great interest from researchers to investigate ternary OSCs and result in many efficient de- vices. Ternary OSCs allow collecting high- and low-energy photons by separated semiconductors in a single active layer to minimize the thermalization loss and broaden absorption range to improve the performance of OSCs. However, most reported ternary OSCs only have active layer of about 100 nm in thick.ess.

关键词： Bins Butyric acid Carboxylation Coherent scattering Crystalline materials Hole mobility Molecules Organic solar cells Thick.films X ray scattering

Hall Effects on Unsteady Magnetohydrodynamic Flow of a Third Grade Fluid

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Chinese Physics Letters 2007年第5期24卷 1129-1132页

作者： k. Fak.ar 徐振礼程艺 Interdisciplinary Center for Theoretical Study University of Science and Technology of China Hefei 230026 Department of Science in Engineering Faculty of Engineering International Islamic University Malaysia Jalan Gombak 53100 Kuala Lumpur Malaysia Department of Mathematics University of Science and Technology of China Hefei 230026

The unsteady magnetohydrodynamic flow of an electrically conducting viscous incompressible third grade fluid bounded by an infinite porous plate is studied with the Hall effect. An external uniform magnetic field is applied perpendicular to the plate and the fluid motion is subjected to a uniform suction and injection. Similarity transformations are employed to reduce the non-linear equations governing the flow under discussion to two ordinary differential equations （with and without dispersion terms）. Using the finite difference scheme, numerical solutions represented by graphs with reference to the various involved parameters of interest are discussed and appropriate conclusions are drawn.

关键词： 3RD GRADE FLUID SYMMETRY ANALYSIS MAGNETIC-FIELD ROTATING-DISk POROUSPLATE COUETTE-FLOW SUCTION

Derivation of Optimal Rotor Topologies for Consequent-Pole PMSM by ON/OFF Method

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CES Transactions on Electrical Machines and Systems 2021年第4期5卷 301-310页

作者： Zhen Sun kota Watanebe Xiaozhuo Xu the Graduate School of Engineering Muroran Institute of TechnologyMuroran 050-8585Japan the School of Electrical Engineering and Automation Henan Polytechnic UniversityJiaozuo 454000China

Consequent-pole permanent magnet synchronous machines(CP-PMSMs)have attracted considerable interest as a means of reducing manufacturing costs through a mark.d reduction in the volume of permanent magnet required to meet a particular torque *** this paper,novel rotor topologies for a CP-PMSM are derived to unlock.the full design space *** ON/OFF method is introduced to manage the laminated steel material distribution over the rotor region,high average torque and low torque ripple are the objects of rotor design,and the immune algorithm is used to search for the optimal material distribution for the formulated *** than 9000 different rotor topologies are created and evaluated within 12 hours by this *** optimal topologies under different design strategy are presented,and performance of these topologies are *** analysis results show that the proposed methodology can deliver novel rotor topologies for the CP-PMSM with surprising torque quality since the torque ripple is suppressed to a low level with no average torque sacrifice.

关键词： Consequent-pole Immune algorithm Permanent magnet synchronous machines Topology optimization

Regulation of Power Conversion in Fuel Cells

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Chemical Research in Chinese Universities 2004年第4期20卷 466-469页

作者： ZHANG J. k. Scott School of Chemical Engineering & Advanced Materials University of Newcastle upon Tyne Newcastle upon TyneSchool of Chemical Engineering & Advanced Materials University of Newcastle upon Tyne Newcastle upon Tyne NE1 7RU UK NE1 7RU UK

Here we report a regulation about power conversion in fuel cells. This regulation is expressed as that total power produced by fuel cells is always proportional to the square of the potential difference between the \{equilibrium\} potential and work.potential. With this regulation we deduced fuel cell performance equation which can describe the potential *** current performance curves, namely, polarization curves of fuel cells with three power source parameters: equilibrium potential E_0; internal resistance R; and power conversion coefficient k. The concept of the power conversion coefficient is a new criterion to evaluate and compare the characteristics and capacity of different fuel cells. The calculated values obtained with this equation agree with practical performance of different types of fuel cells.

关键词： Fuel cell Power conversion coefficient Internal resistance Performance Potential

Identification of ExpIdentification of Expressed Resistance Gene Analogs from Peanut (Arachis hypogaea L.) Expressed Sequence Tags

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Journal of Integrative Plant Biology 2013年第5期55卷 453-461页

作者： Zhanji Liu Suping Feng Manish k. Pandey Xiaoping Chen Albert k. Culbreath Rajeev k. Varshney Baozhu Guo University of Georgia Department of Plant Pathology Shandong Academy of Agricultural Sciences High-Tech Research Center Qiongzhou University College of Bioscience and Biotechnology International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Guangdong Academy of Agricultural Sciences Crops Research Institute US Department of Agriculture Agricultural Research ServiceCrop Protection and Management Research Unit

Low genetic diversity mak.s peanut （Arachis hypogaea L.） very vulnerable to plant pathogens, causing severe yield loss and reduced seed quality. Several hundred partial genomic DNA sequences as nucleotide-binding-site leucine-rich repeat （NBS-LRR） resistance genes （R） have been identified, but a small portion with expressed transcripts has been found. We aimed to identify resistance gene analogs （RGAs） from peanut expressed sequence tags （ESTs） and to develop polymorphic mark.rs. The protein sequences of 54 k.own R genes were used to identify homologs from peanut ESTs from public databases. A total of 1,053 ESTs corresponding to six different classes of k.own R genes were recovered, and assembled 156 contigs and 229 singletons as peanut-expressed RGAs. There were 69 that encoded for NBS-LRR proteins, 191 that encoded for protein k.nases, 82 that encoded for LRR-Pk.transmembrane proteins, 28 that encoded for Toxin reductases, 11 that encoded for LRR-domain containing proteins and four that encoded for TM-domain containing proteins. Twenty-eight simple sequence repeats （SSRs） were identified from 25 peanut expressed RGAs. One SSR polymorphic mark.r （RGA121） was identified. Two polymerase chain reaction-based mark.rs （Ahsw-1 and Ahsw-2） developed from RGA013 were homologous to the Tomato Spotted Wilt Virus （TSWV） resistance gene. All three mark.rs were mapped on the same link.ge group AhIV. These expressed RGAs are the source for RGA-tagged mark.r development and identification of peanut resistance genes.

关键词： Arachis hypogaea expressed sequence tags resistance gene analogs Tomato Spotted Wilt Virus.

Statistical Modeling Studies of Iron Recovery from Red Mud Using Thermal Plasma

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Plasma Science and Technology 2013年第5期15卷 459-464页

作者： Swagat S. RATH Archana PANY k. JAYASANk.R Ajit k. MITRA C. SATISH k.MAR Partha S. MUk.ERJEE Barada k. MISHRA Institute of Minerals and Materials Technology (CSIR) Vedanta Alumina Limited Lanjigarh

Optimization studies of plasma smelting of red mud were carried out. Reduction of the dried red mud fines was done in an extended arc plasma reactor to recover the pig iron. Lime grit and low ash metallurgical （LAM） cok. were used as the flux and reductant, respectively. 2level factorial design was used to study the influence of all parameters on the responses. Response surface modeling was done with the data obtained from statistically designed experiments. Metal recovery at optimum parameters was found to be 79.52%.

关键词： plasma response surface modeling red mud design of experiments optimiza-tion

THE STEP-TRANSITION OPERATORS FOR MULTI-STEP METHODS OF ODE'S

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Journal of Computational Mathematics 1998年第3期16卷 193-202页

作者： Feng k.(ICMSEC, Chinese Academy of Sciences) 中科院计算数学与科学工程计算所北京

In this paper, we propose a new definition of symplectic multistep methods. This definition differs from the old ones in that it is given via the one step method defined directly on M which is corresponding to the m step scheme defined on M while the old definitions are given out by defining a corresponding one step method on M × M ×…× M = Mm with a set of new variables. The new definition gives out a steptransition operator g: M → M. Under our new definition, the Leap-frog method is symplectic only for linear Hamiltonian systems. The transition operator g will be constructed via continued fractions and rational approximations.

关键词： Multi-step methods Explik. and loglik. function Fractional and rational approximation Simplecticity of LMM Nonexistence of SLMM.