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Progress in Natural Science:Materials International 2008年第7期18卷 867-872页

作者： Qing zhang, Jun Huang, Gang Yu * POPs Research Centre, department of Environmental Science and Engineering, {2., beijing 100084, China POPs Research Centre Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

Quantitative structure–property relationship (QSPR) models were developed for soot–water partition coefficient (KSC) values of selected persistent organic pollutants (POPs), i.e. 10 polychlorinated dibenzo-p-dioxins and dibenzofurans, nine polychlorinated biphe- nyls, four polycyclic aromatic hydrocarbons and two polybrominated diphenyl ethers, using partial least squares (PLS) regression. Quan- tum chemical descriptors computed by parameterized model revision 3 Hamiltonian method were used as predictor variables. The cross- validated Q2.um value for the optimal QSPR model is 0.844, indicating a good predictive capability for the logKSC values of these chem- icals. The QSPR results showed that average molecular polarizability (a), standard heat of formation (DHf) and energy of the lowest unoccupied molecular orbital (ELUMO) have dominant effects on KSC of POPs. The results suggested that logKSC values of POPs increase with the increase of a. Contrarily, logKSC values decrease with the increase of ELUMO and DHf of POPs.

关键词： Quantitative structure–property relationships Black carbon Persistent organic pollutants Quantum chemical descriptors Partial least squares

Ultralight X-type lattice sandwich structure (Ⅱ):Micromechanics modeling and finite element analysis

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Science China(Technological sciences) 2009年第9期52卷 2670-2680页

作者： zhang QianCheng1,CHEN AiPing 2.CHEN ChangQing2.3 & LU TianJian2.1 State Key Laboratory for Mechanical Behavior of Materials,School of Material Science and Engineering,Xi’an Jiaotong {2.,Xi’an 710049,China 2.MOE Key Laboratory for Strength and Vibration,School of Aerospace,Xi’an Jiaotong {2.,Xi’an 710049,China 3 department of Engineering Mechanics,AML,tsinghua university,beijing 100084,China State Key Laboratory for Mechanical Behavior of Materials School of Material Science and Engineering Xi’an Jiaotong University Xi’an China MOE Key Laboratory for Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an China department of Engineering Mechanics AML Tsinghua University Beijing China

The methods of homogenization and finite elements are employed to predict the effective elastic constants and stress-strain responses of a new type of lattice structure,the X-structure proposed by the authors in a companion paper. It is shown that in most cases the predictions by the equivalent homogenization theory agree well with the experimental and 3-dimensional finite element calculated results. The theoretical and numerical study supports the argument that the X-structure is superior to the pyramid lattice structure in terms of mechanical strength.

关键词： sandwich panel lattice structure equivalent homogenization finite element model

Fuzzy tolerance quotient spaces and fuzzy subsets

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Science China(Information sciences) 2010年第4期53卷 704-714页

作者： zhang Ling1 & zhang Bo2.3,4* 1Computer Science & Technology College, Anhui {2., Anhui 2.0039, China 2.tate Key Laboratory of Intelligent Technology and Systems, beijing 100084, China 3tsinghua National Laboratory of Information Science & Technology, beijing 100084, China 4Information Science & Technology College, Computer Science & Technology department, tsinghua university, beijing 100084, China 1. Computer Science & Technology College Anhui University Anhui 230039 China2. State Key Laboratory of Intelligent Technology and Systems Beijing 100084 China3. Tsinghua National Laboratory of Information Science & Technology Beijing 100084 China4. Information Science & Technology College Computer Science & Technology Department Tsinghua University Beijing 100084 China

The structure and characteristic of fuzzy subsets are discussed by using the concepts of granulation and hierarchy in quotient space theory. First, the equivalence relation based quotient space theory is extended to the fuzzy tolerance relation. Second, the isomorphism and its discriminant of fuzzy tolerance relations are discussed. Finally, by using the fuzzy tolerance relation to define the fuzzy subset, its properties are addressed. The main results are given below: (1) several equivalent statements of fuzzy tolerance relations; (2. the definition of isomorphism of fuzzy tolerance relations; (3) the isomorphic discriminant of fuzzy tolerance relations; (4) the definition and properties of fuzzy subsets based on the fuzzy tolerance relations; and (5) the necessary and sufficient condition of the isomorphism of fuzzy subsets. These results will help us further comprehend the concepts of fuzzy tolerance relations and fuzzy subsets.

关键词： Fuzzy tolerance relation quotient space isomorphism fuzzy subset

Green Light-Emitting Organic Electroluminescent Device with a New Fluorescent Dye Dispersed in Poly(N-vinylcarbazole) Emitter Layer

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Chinese Chemical Letters 1997年第1期8卷 79-80页

作者： Yong QIU De Qiang zhang Zhi Liang XIE Xiao Xuan LIU(department of Chemistry {2., beijing 100084) TSING HUA UNIV DEPT CHEMBEIJING 100084PEOPLES R CHINA SHANTOU UNIV SHANTOUPEOPLES R CHINA

Double-layer organic electroluminescent devices have been constructed. A new fluorescent dye, 9,10-bis(phenylethynyl)anthracence, was chosen as the dopant which was molecularly dispersed in the polymer film, and green... 详细信息

关键词： Green Light-Emitting Organic Electroluminescent Device with a New Fluorescent Dye Dispersed in Poly N-vinylcarbazole Emitter Layer

A Rationalization of Sympathetic Nucleation-Ledgewise Growth Theory of Bainite Transformation in Fe-C Alloys

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Journal of Materials Science & Technology 2001年第4期17卷 433-438页

作者： Zhigang YANG, Chi zhang, Hongsheng FANG, Jinbo YANG, Bingzhe BAI and Jiajun WANG department of Materials Science and Engineering, {2. beijing 100084, China Tsing Hua Univ Dept Mat Sci & Engn Beijing 100084 Peoples R China

Based on the classic diffusion controlled nucleation and goth theory, the sympathatic nucleation- ledgewise growth mechanism of bainite was studied theoretically for low carbon Fe-C alloys. The rationality of the occurrence of sympathetic nucleation on the terraces of ledges compating with lateral ledge growth and other sites nucleation was demonstrated by the present work quantita- tively The calculations indicated that low reaction temperatures and high carbon concentrations may favor the sympathetic nucleation, thus accounting for the formation of multilayer structures of bainite.

关键词： A Rationalization of Sympathetic Nucleation-Ledgewise Growth Theory of Bainite Transformation in Fe-C Alloys Fe

A stochastic policy search model for matching behavior

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Science China(Information sciences) 2011年第7期54卷 1430-1443页

作者： CHENG ZhenBo 1,2.zhang Yu 1 & DENG ZhiDong 1 1 State Key Laboratory on Intelligent Technology and Systems,tsinghua National Laboratory for Information Science and Technology,{2. of Computer Science,tsinghua university,beijing 100084,China 2.{2. of Computer Science and Technology,Zhejiang university of Technology,Hangzhou 310014,China 1. State Key Laboratory on Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Computer Science Tsinghua University Beijing 100084 China2. Department of Computer Science and Technology Zhejiang University of Technology Hangzhou 310014 China

The matching law is one of the basic empirical laws in decision theory,and it states that a subject’s preference to optional targets depends on which choices are *** this paper,we study the possible mechanisms that explain why subjects’ decisions often obey this *** the basis of reinforcement learning theory,we put forward a decision-making model in which the policy is updated by a policy parameter,and the model might be implemented in the brain through the prefrontal cortex and the basal ganglia neural *** on this model,an algorithm that satisfies the matching law is derived under some simple *** analysis and simulation results show that the decision behavior achieved by the algorithm obeys the matching *** addition,the matching behaviors in two classical experiments are reproduced using the *** results provide a reasonable strategy for the matching law and a useful computational tool for rewarded decision-making tasks.

关键词： policy model matching law reinforcement learning decision-making model

Estimation of LISS(local input-to-state stability) properties for nonlinear systems

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Science China(Technological sciences) 2010年第4期53卷 909-917页

作者： WU ShengYu,MEI ShengWei & zhang XueMin State Key Laboratory of Power Systems,department of Electrical Engineering,{2.,beijing 100084,China 1. State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

Compared with input-to-state stability(ISS) in global version,the concept of local input-to-state stability(LISS) is more relevant and meaningful in *** key of assessing LISS properties lies in investigating three main ingredients,the local region of initial states,the local region of external inputs and the asymptotic *** is the objective of this paper to propose a numerical algorithm for estimating LISS properties on the theoretical foundation of quadratic form LISS-Lyapunov *** developments of linear matrix inequality(LMI) methods,this algorithm is effective and powerful.A typical power electronics based system with common DC bus is served as a demonstration for quantitative results.

关键词： locally input-to-state stability LISS-Lyapunov function linear matrix inequality

Structure and regulatory function of plant transcription factors

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Chinese Science Bulletin 2001年第4期46卷 271-278页

作者： LIU Qiang, zhang Guiyou & CHEN Shouyidepartment of Biological Science and Biotechnology, {2. Univorsity, beijing 100084, China department of Biological Science and Biotechnology, State Laboratory of Biomembrane and Membrane Biotechnology, tsinghua university, beijing 100084, China Institute of Genetics, Chinese Academy of sciences, beijing 100101, China department of Biological Science and Biotechnology Tsinghua University Beijing China department of Biological Science and Biotechnology State Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China Institute of Genetics Chinese Academy of Sciences Beijing China

The expression of inducible genes in plants is regulated by specific transcription factors at the transcrip-tional level. A typical transcription factor usually contains a DNA-binding domain, a transcription regulation domain, a dimerization site and a nuclear localization domain. These functional domains define the characteristic, localization and regulatory role of a transcription factor. Transcription factors recognize and bind to specific cis-acting elements or interact with other proteins, and then activate or repress the transcription of target genes by their functional domains. In recent years, elucidation on the structure and function of transcription factors has become an important subject in plant molecular biology.

关键词： transcription factor DNA-binding domain cis-acting element.

Relation between seed size in different plant species and response of their seedlings to double CO_2

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Chinese Science Bulletin 1997年第4期42卷 331-333页

作者： DING Li, zhang Chonghao, BAI Kezhi and KUANG Tingyun1 department of Biology, {2. Normal university, {2. 100875, China 2. Institute of Botany, Chinese Academy of sciences, {2. 100093, China department of Biology Beijing Normal University Beijing China Institute of Botany Chinese Academy of Sciences Beijing China

ATMOSPHERIC CO2.concentration is predicted to increase to 700μL/L by the middle of the 2.st century. The impacts of raising CO2.on vegetation and ecosystem have been intensively studied. It is well known that C3 spec... 详细信息

ATMOSPHERIC CO2./sub> concentration is predicted to increase to 700μL/L by the middle of the 2.st century. The impacts of raising CO2./sub> on vegetation and ecosystem have been intensively studied. It is well known that C3 species and C4 species responded much differently to double CO2./sub>. Potential enhancement of photosynthesis efficiency induced by double CO2./sub> in C3 plants was almost 66%, but in C4 plants only 4%. The response to double CO2./sub> in C3 species might

关键词： double CO2 seed size seedling growth percentage enhancement.

An equality on Hochschild homology groups

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Chinese Science Bulletin 1997年第8期42卷 624-627页

作者： zhang Pu and LIU Shaoxue1. department of Mathematics, {2. of Science and Technology of China, Hefei 2.002., China 2. department of Mathematics, beijing Normal {2., beijing 100875, China department of Mathematics University of Science and Technology of China Hefei China department of Mathematics Beijing Normal University Beijing China

LET A be finite-dimensional algebra over field k,and Ae the enveloping algebra of A,i.e.Ae=A kAop,where Aop is the opposite algebra of *** A-bimodule has a natural left Ae-module structure as follows:

关键词： finite-dimensional algebra Hochschild homology groups dimensions.