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Science China Earth Sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., China 2. Department of Atmospheric Science, Yunnan University, Kunming 650091, China 3. Graduate University of the Chinese Academy of Sciences, beijing 10004., China 1. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric Science Yunnan University Kunming 650091 China 3. Graduate University of the Chinese Academy of Sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Approximation of dense-n/2.subgraph and table compression problems

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Science China Mathematics 2005年第9期48卷 1223-1233页

作者： XU Dachuan~1 HAN Jiye~2.& DU Dongle~3 1. College of Applied Sciences,beijing University of Technology,beijing 10002.,China 2. Institute of Applied Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,beijing 100080,China 3. Faculty of Administration,University of New Brunswick,P.O.Box 4400,Fredericton,NB E3B 5A3,Canada College of Applied Sciences Beijing University of Technology Beijing 100022 China Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Faculty of Administration University of New Brunswick P.O. Box 4400 Fredericton NB E3B 5A3 Canada

We develop improved approximation algorithms for two NP-hard problems: the dense-n/2.subgraph and table *** on SDP relaxation and advanced rounding techniques,we first propose 0. 5982.and 0. 5970-approximation algorithms respec- tively for the dense-n/2.subgraph problem (DSP) and the table compression problem (TCP). Then we improve these bounds to 0. 62.3 and 0. 6708 respectively for DSP and TCP by adding triangle inequalities to strengthen the SDP *** results for TCP beat the 0. 5 bound of a simple greedy algorithm on this problem,and hence answer an open question of Anderson in an affirmative way.

关键词： dense-n/2.subgraph problem(DSP) table compression problem(TCP) SDP approximation ratio

Corrosion and electrochemical behavior of as-cast Mg-5Y-7Gd-1Nd-0.5Zr magnesium alloys in 5%NaCl aqueous solution

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Progress in Natural Science:Materials International 2011年第4期21卷 314-321页

作者： Xin ZHANG~(1,2.3),Kui ZHANG~1,Xing-gang LI~1,Cong WANG~4,Hong-wei LI~(2.3),Chang-shun WANG~(2.3),Xia DENG~1 1.State Key Laboratory for Fabrication and Processing of Nonferrous Metals, beijing General Research Institute for Nonferrous Metals,beijing 100088,China 2.beijing Engineering Research Center for Advanced Manufacturing and Evaluation of Special Vehicle Parts,beijing 100072.China 3.Institute of Technology,beijing North Vehicle Group Corporation,beijing 100072.China 4.Fengtai Military Representative Office,beijing Military Representative Office,PLA,beijing 100072.China [a] State Key Laboratory for Fabrication and Processing of Nonferrous Metals Beijing General Research Institute for Nonferrous Metals Beijing 100088 China [b] beijing Engineering Research Center for Advanced Manufacturing and Evaluation of Special Vehicle Parts Beijing 100072 China [c] Institute of Technology Beijing North Vehicle Group Corporation Beijing 100072 China [d] Fengtai Military Representative Office Beijing Military Representative Office PLA Beijing 100072 China

The corrosion mechanism of the as-cast Mg-5Y-7Gd-1Nd-0.5Zr magnesium alloy immersed in 5%NaCl aqueous solution was investigated by electrochemical test and *** electrochemical results indicate that the corrosion resistance of Mg-5Y-7Gd-1Nd-0.5Zr alloy in 5%NaCl aqueous solution gradually deteriorates with immersion time increasing from 2.h,2. h,60 h,to 108 h,which is consistent with the SEM observation of corrosion *** Cl-anion leads to the initiation and development of the corrosion pits,and Mg-5Y-7Gd-1Nd-0.5Zr alloy exhibits filiform type of attack under significant anodic control of magnesium solution *** corrosion potential becomes noble with increasing immersion time.

关键词： magnesium alloys Mg-5Y-7Gd-1Nd-0.5Zr corrosion electrochemical behavior

Geographical Agglomeration of Chinese Manufacturing Industries

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中国人口·资源与环境：英文版 2007年第2期5卷 3-11页

作者： Zhang Hua 1, 2. Zheng Wei3 1. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, China 2. Graduate School of the Chinese Academy of Sciences, beijing 100039, China 3. School of Geography, beijing Normal University, beijing 100875, China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China School of Geography Beijing Normal University Beijing 100875 China

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of China, this paper ex- amines the geographical agglomeration of Chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of Chinese manu- facturing industries in 1996, 2.01 and 2.04, agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–2.04.

关键词： industrial agglomeration manufacturing industries the MS index

A MESSAGE-DRIVING FORMALISM FOR MODELING AND SIMULATION OF MULTI-AGENT SUPPLY CHAIN SYSTEMS

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Journal of Systems Science and Systems Engineering 2011年第4期20卷 385-399页

作者： Wenzhe TAN1 Yueting CHAI2.Yi LIU3 1Department of Automation, Tsinghua University, beijing, 100084, China 2.epartment of Automation, Tsinghua University, beijing, 100084, China 3Department of Automation, Tsinghua University, beijing, 100084, China Department of Automation Tsinghua University Beijing China

To acquire a competitive advantage in the expanding market, manufacturing enterprises should be able to manage their supply chains as effectively as possible. It is now becoming popular to model supply chains as multi-agent systems and use discrete event simulation to learn more about their behaviors or investigate the implications of alternative configurations. In order to enhance the computational efficiency and keep the simulation credibility, this paper proposes a message-driving formalism for the simulation of multi-agent supply chain systems. Through the message-driving formalism, the problem of shared variables is addressed and the parallel operation of agents is implemented. Simulation experiments with a prototype implementation show that the message-driving formalism is able to provide credible results in significantly less simulation time.

关键词： Supply chain multi-agent system modeling and simulation parallel discrete event simulation message-driving formalism

Robust multiuser MIMO scheduling algorithms with imperfect CSI

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Science China(Information Sciences) 2012年第4期55卷 815-826页

作者： MAO JunLing 1,3,GAO JinChun 1,3,LIU YuanAn 1,3,XIE Gang 2.3 & ZHANG Jian 1,3 1 School of Electronic Engineering,beijing University of Posts and Telecommunications,beijing 100876,China 2.School of Information and Communication Engineering,beijing University of Posts and Telecommunications,beijing 100876,China 3 Key Lab of Universal Wireless Communications,Ministry of Education,beijing University of Posts and Telecommunications,beijing 100876,China 1. School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Lab of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Robust multiuser multiple-input-multiple-output (MIMO) scheduling algorithms are proposed in this *** imperfect channel state information (CSI),traditional scheduling algorithms for the multiuser MIMO system based on the zero forcing precoding scheme will lose some performance due to the multi-user interference (MUI).In order to improve the system average throughput,we study the robust multiuser MIMO scheduling problem with imperfect *** the average capacity formula,we derive a robust factor which can transform the robust multiuser MIMO scheduling problem into the traditional one,thus most existing non-robust scheduling algorithms can be robust if this factor is *** results show that compared with the traditional algorithms,the proposed robust algorithms can improve the system average throughput significantly under the CSI error environment.

关键词： multiuser MIMO (MU-MIMO) scheduling robust imperfect CSI

Solvation effects on brain uptakes of isomers of ^(99m)Tc brain imaging agents

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Chinese Science Bulletin 2002年第21期47卷 1786-1791页

作者： JIA Hongmei, MA Xiaohui, WANG Cunxin & LIU Boli1. Department of Chemistry, beijing Normal University, beijing 100875, China 2. Center for Biomedical Engineering, beijing Polytechnic University, beijing 10002., China 1. Department of Chemistry Beijing Normal University Beijing 100875 China 2. Center for Biomedical Engineering Beijing Polytechnic University Beijing 100022 China

Analysis of electrostatic hydration free energies of the isomers of the 99mTc-BAT and 99mTc-DADT complexes is carried out using the computer simulation technique. The results show that not only a correlation exists between the logarithm of the brain uptake and the electrostatic hydration free energy for the isomers of 99mTc-brain radiopharmaceu-ticals, but also a linear relationship exists between the logarithm of the ratio of the brain uptake of the syn isomer to that of the anti one and the difference between the electrostatic hydration free energy of the syn-isomer and that of the anti one. Furthermore, the investigation on the important factors influencing the brain uptakes of 99mTc-radiophar-maceuticals and the reasons of the different biodistribution of the isomers of the 99mTc-complexes is explored at the molecular level. The results may provide a reference for the rational drug design of brain imaging agents.

关键词： 99mTc-brain imaging agent isomer brain uptake electro-static hydration free energy.

Variation properties of ionospheric eclipse factor and ionospheric influence factor

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Progress in Natural Science:Materials International 2005年第6期15卷 573-576页

作者： ZHAO Chunmei 1,2.*, YUAN Yunbin1, OU Jikun1 and CHEN Jinping3(1. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China 2. Graduate School of Chinese Academy of Sciences, beijing 100039, China 3. Department of Precision Instrument and Mechanology, Tsinghua University, beijing 100084, China) Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Graduate School of Chinese Academy of Sciences Beijing 100039 China Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

关键词： GPS ionospheric eclipse factor ionospheric influence factor

Study on the two and three-parameter working stability regions of 3Y-TZP suspension

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Science China(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2. ZHANG Xinni3, CHEN Sha’ou3 & QI Ping3 1. Department of Chemistry, Qingdao University, Qingdao 2.6071, China 2. Department of Chemistry, Tsinghua University, beijing 100084, China 3. Department of Physics, Qingdao University, Qingdao 2.6071, China 1. Department of Chemistry Qingdao University Qingdao 266071 China 2. Department of Chemistry Tsinghua University Beijing 100084 China 3. Department of Physics Qingdao University Qingdao 266071 China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3Y-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3Y-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3Y-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3Y-TZP, suspension, stability, DLVO theory, interparticle potential energy.

Reduced analysis and confirmatory research on co-adaptability theoretical solution to conflicting events in construction engineering projects

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Science China(Technological Sciences) 2010年第2期53卷 480-485页

作者： HOU XueLiang1 , LU Mei2.& WANG Kai3 1 School of Business Administration, North China Electric Power University, beijing 102.06, China 2.Department of Construction Management, Tsinghua University, beijing 100084, China 3 College of Management, beijing Jiaotong University, beijing 100084, China 1. School of Business Administration North China Electric Power University Beijing 102206 China2. Department of Construction Management Tsinghua University Beijing 100084 China3. College of Management Beijing Jiaotong University Beijing 100084 China

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

关键词： construction project conflict theoretical solution reduced analysis ISM confirmatory research