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Flow imbalance in MHD flows in splitting ducts with locally different electric conductivities of the walls

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Journal of Hydrodynamics 2018年第5期30卷 920-927页

作者： Yang Luo Mengqi Zhu c.N.kim Department of Mechanical Engineering Graduate School Kyung Hee University Department of Mechanical Engineering College of Engineering Kyung Hee University

In this study, three-dimensional liquid-metal magnetohydrodynamic splitting flows in a duct with one inflow channel and two outflow channels with locally different wall electric conductivities（different conductance ratios） are computationally examined. The numerical calculation is achieved with the use of cFX code, with a structured grid system chosen after a series of mesh independence tests. The detailed features of the MHD flows are depicted in a case where the electric conductivities of the two outflow ducts are quite different. Also, the interdependency among the current, fluid velocity, pressure and electric potential is elucidated in order to describe the electromagnetic characteristics of the liquid-metal flows. The result shows that the imbalance of the mass flow rate in the two outflow channels strongly depends on the wall conductivity（i.e., conductance ratio） of each outflow channel.

关键词： Liquid metal flow splitting duct flow imbalance numerical examination conductance ratio

Intelligent Deployment Model for Target coverage in Wireless Sensor Network

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Intelligent Automation & Soft computing 2023年第1期35卷 739-754页

作者： k.Subramanian S.Shanmugavel Department of EcE National Engineering CollegeKovilpattiTamilnaduIndia

Target coverage and continuous connection are the major recital factors for Wireless Sensor Network(WSN).Several previous research works studied various algorithms for target coverage difficulties;however they lacked to focus on improving the network’s life time in terms of *** research work mainly focuses on target coverage and area coverage problem in a heterogeneous WSN with increased network *** dynamic behavior of the target nodes is unpredictable,because the target nodes may move at any time in any direction of the ***,target coverage becomes a major problem in WSN and its *** solve the issue,this research work is motivated to design and develop an intelligent model named Distributed Flexible Wheel chain(DFWc)model for efficient target coverage and area coverage in WSN *** number of target nodes is covered by minimum number of sensor nodes that can improve energy *** be specific,DFWc motivated at obtaining lesser connected target coverage,where every target is available in the monitoring area is covered by a smaller number of sensor *** simulation results show that the proposed DFWc model outperforms the existing models with improved performance.

关键词： WSN target coverage DF Wc network coverage

Reviewing perovskite oxide sites influence on electrocatalytic reactions for high energy density devices

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Journal of Energy chemistry 2023年第6期81卷 1-19,I0002页

作者： Lorrane c.c.B.Oliveira Raissa Venâncio Paulo V.F.de Azevedo chayene G.Anchieta Thayane c.M.Nepel cristiane B.Rodella Hudson Zanin Gustavo Doubek Advanced Energy Storage Division Laboratory of Advanced Batteries(LAB)Center for Innovation on New Energies(CINE)School of Chemical EngineeringUniversity of Campinas(Unicamp)CampinasSao Paulo 13083-852Brazil Advanced Energy Storage Division Center for Innovation on New Energies(CINE)Brazilian Renewable Energies(BREnergies)groupManufacturing GroupSchool of Electrical and Computer EngineeringUniversity of Campinas(UNICAMP)CampinasSão Paulo 13083-852Brazil Paul Scherrer Institut(PSI) Swiss Light Source(SLS)Forschungsstrasse 1115232 Villigen PSIAargauSwitzerland Brazilian center for Research in Energy and Materials(cNPEM)/Brazilian Synchrotron Light Laboratory(LNLS) CampinasSão Paulo 13083-100Brazil

Batteries,fuel cells,and supercapacitors are electrochemical devices already on the market and still need a boost in kinetics to match the high energy density demand of *** have attracted the scientific community's attention in the last decade due to their electrocatalytic activity,chemical and structural properties,tunability,low cost,and *** have been made to understand the active sites and the operational mechanisms in perovskite oxides to shape them as an electrocatalyst in advanced energy *** the role of perovskites is the key to engineering more controlled and efficient electrocatalysts via chemical synthesis,and there is still much to *** review highlights the use of perovskites in different energy storage and conversion *** A,B,and A&B doping-site effects are analyzed to understand the opportunities and challenges related to this class of *** addition,the synthesis methods and the properties related to the doping site are described and summarized.

关键词： Perovskites Energy storage systems Electrocatalysts Battery Oxide fuel cells capacitors

A new modified group explicit iterative method for the numerical solution of time dependent viscous Burgers’equation

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International Journal of Modeling, Simulation, and Scientific computing 2014年第2期5卷 112-129页

作者： Jyoti Talwar R.k.Mohanty Department of Mathematics Faculty of Mathematical Sciences University of DelhiDelhi-110007India Department of Applied Mathematics South Asian University Akbar BhawanChanakyapuriNew Delhi-110021India

In this article,we discuss a new smart alternating group explicit method based on off-step discretization for the solution of time dependent viscous Burgers’equation in rectangu-lar *** convergence analysis for the new iteration method is discussed in *** compared the results of Burgers’equation obtained by using the proposed iterative method with the results obtained by other iterative methods to demonstrate computationally the efficiency of the proposed method.

关键词： Nonlinear parabolic equation off-step variable mesh discretization rectangu-lar and polar coordinates group explicit method Burgers'equation Reynolds number

Estimation of Mean in Double Sampling Using Exponential Technique on Multi-auxiliary Variates

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communications in Mathematics and Statistics 2017年第4期5卷 429-445页

作者： Manish kumar Gajendra k.Vishwakarma centre for Applied Mathematics Central University of JharkhandBrambe 835205India Department of Applied Mathematics Indian Institute of Technology(ISM)DhanbadDhanbad 826004India

This paper presents exponential-type ratio and product estimators for a finite population mean in double sampling using information on several auxiliary *** proposed estimators can be viewed as a generalization over the estimators suggested by Singh and Vishwakarma(Austrian J Stat 36(3):217–225,2007).The expressions for biases and mean square errors(MSEs)of the proposed estimators have been derived to the first degree of *** addition,the expressions for minimum attainable MSEs are also investigated using the criterion for optimality of the *** empirical study is carried out in the support of the present *** theoretical andempirical findings are encouraging and support thesoundness that the proposed procedures for mean estimation perform better than the usual unbiased estimators and other well-known estimators under some realistic conditions.

关键词： Study variate Auxiliary variate Double sampling Bias MSE

Dynamic Mechanical Relaxation in Bulk Metallic Glasses:A Review

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Journal of Materials Science & Technology 2014年第6期30卷 523-545页

作者： J.c.Qiao J.M.Pelletier Université de Lyon CNRS France INSA-Lyon MATEIS UMR5510 F-69621 Villeurbanne France

Metallic glasses have aroused considerable interest in the past decades because they exhibit fascinating properties. First, this article briefly outlines the mechanical, thermal properties and application of the metallic glasses. In addition, we focus on the dynamic mechanical relaxation behaviors, i.e. main （α） and secondary （β） relaxations, in metallic glasses. The mechanical relaxation behaviors are connected to the mechanical properties and physical properties in glassy materials. The main relaxation in glassy materials is related to the glass transition phenomenon and viscous flow. On the other hand, the β relaxation is linked to many fundamental issues in metallic glasses. In these materials relaxation processes are directly related to the plastic deformation mechanism. The mechanical relaxations, particularly, the β relaxation provides an excellent opportunity to design metallic glasses with desired physical and mechanical properties. We demonstrate the universal characteristics of main relaxation in metallic glasses. The phenomenological models and the physical theories are introduced to describe the main relaxation in metallic glasses. In parallel, we show the dependence of the α. and β relaxations on the thermal treatments in metallic glasses. Finally, we analyze the correlation between the atomic mobility and the thermo-mechanical treatments in metallic glasses. On the one hand, the atomic mobility in metallic glasses is reduced by physical aging or crystallization. On the other hand, the atomic mobility in metallic glass is enhanced by deformation （i.e. compression and cold rolling）. Importantly, to analyze the atomic mobility in amorphous materials, a physical theory is introduced. This model invokes the concept of quasi-point defects, which correspond to the density fluctuations in the glassy materials.

关键词： Metallic glasses Mechanical properties Main relaxation Secondary relaxation Physical analysis

The diffusive model for West Nile virus with advection and expanding fronts in a heterogeneous environment

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International Journal of Biomathematics 2020年第7期13卷 29-50页

作者： Zhengdi Zhang Abdelrazig k.Tarboush Faculty of Science Jiangsu University Zhenjiang 212013P.R.China Department of Mathematics Faculty of Education University of KhartoumKhartoum 321Sudan

In this paper,we investigate a reaction-diffusion-advection model with expanding fronts,which models the spatial transmission of West Nile virus(WNv)in a heterogeneous environment.A free boundary problem is formulated and the global existence and uniqueness of the solution is *** addition to a classical basic reproduction number,the spatial-temporal basic reproduction number for the model with null Dirichlet boundary condition is introduced and the risk index associated with the virus in spatial setting is defined,and their properties are *** conditions for the WNv to vanish or spread are given,and the asymptotic behavior of the solution to the free boundary problem when the spreading occurs is *** results show that the initial number of infected populations and the expanding capability of the expanding fronts exhibit important impacts on the extinction or persistence of the virus.

关键词： West Nile virus free boundary advection risk index spreading and vanishing heterogeneous environment

constraints on treeline advance in a warming climate:a test of the reproduction limitation hypothesis

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Journal of Plant Ecology 2018年第3期11卷 411-422页

作者： Dasvinder kambo Ryan k.Danby Department of Geography Queen’s University99 University AvenueKingstonOntario K7L 3N6Canada School of Environmental Studies Queen’s University99 University AvenueKingstonOntario K7L 3N6Canada

Aims Several mechanistic hypotheses have been developed to explain the existence of alpine treelines *** reproduction limita-tion hypothesis(RLH)postulates that reproductive processes such as seed production and dispersal are restricted in treeline envi-ronments,thereby limiting the establishment of new individuals in advance of extant *** its popularity,no study has tested this hypothesis in a comprehensive *** this experi-ment,we attempted to answer whether there are enough viable seeds being dispersed beyond treeline for sexually mediated tree-line advance,and what the implications of climate change might be on these *** We established 30 plots across two aspects(north ***)and three elevational habitats(forest,treeline and tundra)in a white spruce(Picea glauca)boreal forest-alpine tundra ecotone in south-west Yukon,*** each plot,tree characteristics,seed produc-tion and predispersal damage were ***,eight dispersal trays were positioned in each plot to measure seed rain,and germination trials with and without predation exclosures were constructed in a subset of plots to quantify dispersal and germina-tion *** Findings Results were highly variable both temporally and *** 2014,a mast year,69%of adult trees produced cones compared to 0.4%in the following *** density of trees in forest plots compared to treeline and tundra resulted in greater seed production at lower *** all plots,88%of seeds were damaged before dispersal or were not *** plots had significantly greater predispersal *** rain was greater in south-facing plots than north-facing *** than 2%of seeds produced on the landscape were dispersed into Tundra plots,located 50 m above *** was a net movement of seeds from the north-facing slope to the south at our study site,likely due to prevailing winds during the dispersal *** counts were more

关键词： altitudinal gradients treeline dynamics predispersal seed damage seed predation seed masts ecotones

管道内甲烷-空气预混火焰传播特性的实验与数值模拟研究

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中国科学技术大学学报 2009年第4期39卷 419-423页

作者：何学超孙金华陈先锋袁国杰中国科学技术大学火灾科学国家重点实验室安徽合肥230027 中国科学技术大学苏州研究院江苏苏州215123 武汉理工大学资源与环境工程学院湖北武汉430070 香港城市大学建筑系中国香港999077

采用高速纹影摄像系统、压力传感器等对小型水平封闭管道内甲烷-空气预混燃烧火焰的传播过程进行了实验研究,得到了火焰锋面结构、传播速度和压力随时间的变化关系.研究结果表明,管道内预混火焰传播过程中,火焰结构会发生明显变化,即从... 详细信息

采用高速纹影摄像系统、压力传感器等对小型水平封闭管道内甲烷-空气预混燃烧火焰的传播过程进行了实验研究,得到了火焰锋面结构、传播速度和压力随时间的变化关系.研究结果表明,管道内预混火焰传播过程中,火焰结构会发生明显变化,即从向未燃气体凸出的球形层流火焰转变成向已燃气体凹陷的V形湍流火焰,同时伴有火焰传播速度的减小、压力的不断增大.另外运用标准k-ε模型,对非定常时的甲烷预混燃烧火焰进行数值模拟,得到了与实验结果类似的火焰传播特性和火焰结构的变化规律.

关键词：预混火焰实验研究数值模拟基元反应