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Application of polynomial chaos on numerical simulation of stochastic cavity flow

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Science china(Technological Sciences) 2010年第10期53卷 2853-2861页

作者： WANG XiaoDong1,2 & KANG Shun1 1 Key Laboratory of Condition Monitoring and Control for power Plant Equipment, Ministry of Education, school of energy power and mechanical engineering, north china electric power university, beijing 1.2206, china 2 Department of mechanical engineering, Vrije Universiteit Brussel, Brussels 1050, Belgium 1. Key Laboratory of Condition Monitoring and Control for power Plant Equipment Ministry of Education School of Energy Power and Mechanical Engineering North China Electric Power University Beijing 102206 China2. Department of Mechanical Engineering Vrije Universiteit Brussel Brussels 1050 Belgium

In present paper,the mathematic background of intrusive polynomial chaos (IPC) method and coupling process with one dimension Euler equation were introduced. The IPC method was implemented for the 2D compressible stochastic Navier-Stokes equations to simulate the non-deterministic behavior of a lid driven cavity flow under the influence of uncertainties. The driven velocity and fluid viscosity were supposed respectively to be the uncertain variable which has Gaussian probability distribution. Based on the validation with benchmark results,discussions were mainly focused on the statistic properties of velocity distribution. The results indicated the effect of IPC method on the simulation of propagation of uncertainty in the flow field. For the simulated results of 2D cavity flow,influence of the driven velocity uncertainty is larger than that of viscosity.

关键词： non-deterministic polynomial chaos numerical simulation lid driven cavity flow

Analysis of leakage current in GaAs micro-solar cell arrays

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Science china(Technological Sciences) 2010年第5期53卷 1240-1246页

作者： WANG YanShuo1,CHEN NuoFu1,2,3,ZHANG XingWang1,BAI YiMing1,WANG Yu1,HUANG TianMao1,ZHANG Han1 & SHI HuiWei1 1 Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,PO Box 912,beijing 100083,china 2 school of Renewable energy engineering,north china electric power university,beijing 1.2206,china 3 National Laboratory of Micro-Gravity,Institute of Mechanics,Chinese Academy of Sciences,beijing 100080,china 1. Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 China2. School of Renewable Energy Engineering North China Electric Power University Beijing 102206 China3. National Laboratory of Micro-Gravity Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

The output characteristics of micro-solar cell arrays are analyzed on the basis of a modified model in which the shunt resistance between cell lines results in current *** modification mainly consists of adding a shunt resistor network to the traditional *** obtained results agree well with the reported experimental *** calculation results demonstrate that leakage current in substrate affects seriously the performance of GaAs micro-solar cell *** performance of arrays can be improved by reducing the number of cells per *** addition,at a certain level of integration,an appropriate space occupancy rate of the single cell is recommended for ensuring high open circuit voltages,and it is more appropriate to set the rates at 80%-90% through the calculation.

关键词： micro-solar cell MEMS(micro-electromechanical systems) leakage current

Experimental study on drying of typical MSW under incinerator-like conditions

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Science china(Technological Sciences) 2007年第5期50卷 636-643页

作者： ZHANG YanGuo1, CHEN MeiQian2, MENG AiHong1, LI QingHai1 & CHEN YunXuan2 1 Key Laboratory for Thermal Science and power engineering of Ministry of Education, Tsinghua university, beijing 100084, china 2 school of mechanical, Electronical and Control engineering, beijing Jiaotong university, beijing 100044, china 1. Key Laboratory for Thermal Science and power engineering of Ministry of Education Tsinghua University Beijing 100084 China 2. school of mechanical Electronical and Control Engineering Beijing Jiaotong University Beijing 100044 China

In this paper, a series of experiments were conducted to investigate the drying of typical municipal solid wastes (MSW) in a muffle incinerator. From the experimental drying characteristic curves, the effects of temperature on drying process were observed to be more obvious in the low temperature region than in the high tem- perature region in muffle incinerator. At a specified drying temperature, drying time was highly dependent upon the packed waste thickness, having an exponent rela- tion with the thickness. When the drying temperature increased or the thickness of potato bulks was diminished, the maximum drying rate reduced. Based on the first-order reaction, activation energy (Ea), and factor A of potato and cabbage were determined.

关键词： drying, MSW, potato blocks, cabbage stems, temperature, dying rate

Evaluating the effect of dislocation on the photovoltaic performance of metamorphic tandem solar cells

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中国科学：技术科学英文版 2010年第9期53卷 2569-2574页

作者： ZHANG Han1,CHEN NuoFu2,3,WANG Yu1,ZHANG XingWang1,YIN ZhiGang1,SHI HuiWei1,WANG YanSuo1,HUANG TianMao1,BAI YiMing2 & FU Zhen11 Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,P.O.Box 912,beijing 100083,china 2 school of Renewable energy engineering,north china electric power university,beijing 1.2206,china 3 State Key Laboratory of Silicon Materials,Zhejiang university,Hangzhou 310027,china 1. Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences P.O. Box 912 Beijing 100083 China2. School of Renewable Energy Engineering North China Electric Power University Beijing 102206 China3. State Key Laboratory of Silicon Materials Zhejiang University Hangzhou 310027 China

The photovoltaic conversion efficiency for monolithic GaInP/GaInAs/Ge triple-junction cell with various bandgap combination (300 suns,AM1.5d) was theoretically *** impressive improvement on conversion efficiency was observed for a bandgap combination of 1.708,1.194,and 0.67 eV.A theoretical investigation was carried out on the effect of dislocation on the metamorphic structure’s efficiency by regarding dislocation as minority-carrier recombination *** results showed that only when dislocation density was less than 1.6×106 cm-2,can this metamorphic combination exhibit its efficiency advantage over the fully-matched *** addition,we also briefly evaluated the lattice misfit dependence of the dislocation density for a group of metamorphic triple-junction system,and used it as guidance for the choice of the proper cell structure.

关键词： tandem solar cell theoretical efficiency dislocation buffer layers

Chimney Effect Assessment of the Double-skin Facade

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湖南大学学报（自然科学版） 2009年第S1期36卷 146-150页

作者： QIU Zhong-zhu1,LI Peng2,CHOW Tin-tai3,REN Jian-xing1,WANG Wen-huan1(1.school of energy & Environment engineering,Shanghai university of electric power,Shanghai 20090,china 2.school of mechanical engineering,Tongji university,Shanghai 200092,china 3.Division of Building Science & Technology,City university of Hong Kong,Hong Kong SAR,china) school of energy and Environment engineering Shanghai University of Electric Power Shanghai 200090 China school of mechanical engineering Tongji University Shanghai 200092 China Division of Building Science and Technology City University of Hong Kong Hong Kong Hong Kong

The mathematic model of heat transfer through ventilated double glazing was verified with the measured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement *** the model validation,the double-skin facade assessment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work *** air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn *** differences of chimney effect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventilated double skin facade were presented.

关键词： chimney effect assessment double-skin facade

Deterioration Mechanisms of Sulfate Attack on Concrete under Alternate Action

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Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 355-359页

作者：高润东 State Key Laboratory of Hydroscience and engineering Tsinghua University

By micro- and macro-observations, the deterioration mechanisms of concrete under alternate action between repeated sub-high temperature/cooling by water and sodium sulfate solution attack （TW-SA） were studied; meanwhile, the single sodium sulfate solution attack （SA） was also done as comparison. Micro-observations included the analysis of attack products by thermal analysis method and the determination of sulfate-ion content from surface to interior by chemical titrating method （modified barium sulfate gravimetric method）. Macro-observations mainly included the mechanical behaviors such as compressive strength, splitting strength. The experimental results indicate, in both cases, the main attack product is ettringite, only in the first layer of case SA some gypsum is checked; in case SA, the sulfate ions mainly concentrate in the surface layer, so the attack is relatively mild; but in case TW-SA, the repeated sub-high temperature/cooling by water promotes the sulfate ions diffusing inwards, which leads to obvious strength degradation.

关键词： concrete sulfate repeated sub-high temperature/cooling by water attack product sulfate-ion content strength

A Win-win Strategy for Risk Decision-making under a BOT Scheme

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A Win-win Strategy for Risk Decision-making under a BOT Sche...

Simulation on the Melt Flow in Laser Full Penetration Welding with a Model Including a Non-Rotational Symme-try Keyhole Based on energy Balance

The Ninth International Conference on Information and Management Sciences

作者： Wenbei Zhan school of energy & power engineering north china electric power university beijing 1.2206 china

＜正＞The Decision-makings can be rather difficult when dealing with two or more interest groups,especially under certain *** this paper,we studied highway toll and capacity programming in a Build-Operate -Transfer scheme under demand *** solve the network design problem with sophisticated benefits relatives,we followed the contentment principle and developed a dependent-chance programming model. The investor receives a desired profit,and at the meantime,the government receives a desired social-welfare, which can be called a win-win ***, we use a genetic algorithm to simulate the model.

关键词： Contentment principle chance-dependent programming dependent-chance programming win-win strategy genetic algorithm

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稀有金属材料与工程 2011年第S4期40卷 120-124页

作者： Zhang L J1,Zhang J X1,Wu B1,2,Chen L2,Gong S L2,Wang H R3 1 State Key Laboratory of mechanical Behavior for Materials,Xi’an Jiaotong university,Xi’an 710049,china2 power Beam Processing Dept.,Avic beijing Aeronautical Manufacturing Technology Research Institute,beijing 100024,china3 school of energy and power engineering,Xi’an Jiaotong university,Xi’an 710049,china Xi An Jiao Tong Univ Sch Energy & Power Engn Xian 710049 Peoples R China Xi An Jiao Tong Univ State Key Lab Mech Behav Mat Xian 710049 Peoples R China Avic beijing Aeronaut Mfg Technol Res Inst Power Beam Proc Dept Beijing 100024 Peoples R China

A three dimensional model including a non-rotational symmetry keyhole of which the geometry is calculated base on the energy balance at keyhole wall is created to simulate the heat transfer and fluid flow within the molten pool during laser full penetration welding of titanium alloy *** order to take into account the effects of multiple reflections within the keyhole,a ray tracing method is employed and the coordinate dependent heat flux obtained is exerted on keyhole wall during the simulation on the heat transfer and fluid flow within molten ***,the computed weld cross sectional profile is compared with the experimental result to verify the model and it is fond that the simulation result is consists with experimental result.

关键词： laser welding titanium alloy non-rotational symmetry keyhole simulation

Application Study of Cost Control in The power Supply Enterprise

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Application Study of Cost Control in The Power Supply Enterp...