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Journal of Materials Science & technology 1995年第2期11卷 141-152页

作者： Mingshi SONG Sizhu WU and Xiuyun DU(research institute of Polymeric Materials, beijing university of Chemical technology, beijing, 100029, china) beijing Univ of Chemical technology Beijing China

An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the dependence of ηo and τt on M3.4 were derived from the theory of non-linear viscoelasticity with constraints of entanglements for polymer melts and substituted into the Oldroye-Walters-Fredickson constitutive equation. An integral constitutive equation for polymer melts was consequently obtained. Some material functions of the constitutive equation related to certain 'test flow' are examined as follows : (1) simple steady shear flow; (2) steady elongation flow; (3) small-amplitude oscillatory shear flow; (4) stress growth upon the inception of steady shear elongation flow; (5) stress relaxation (modulus and compllance). These theoretical relations for simple steady shear flow were compared with experimental data from our laboratory and references for various polymer melts and concentrated solutions. A good agreement between the theory and experiment was achieved.

关键词： LDPE Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Flow GR

CUDA-Zero:a framework for porting shared memory GPU applications to multi-GPUs

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Science china(information Sciences) 2012年第3期55卷 663-676页

作者： CHEN DeHao , CHEN WenGuang & ZHENG WeiMin Department of Computer Science and technology, tsinghua university, beijing 100084, china 1. Department of Computer Science and technology Tsinghua University Beijing 100084 China

As the prevalence of general purpose computations on GPU, shared memory programming models were proposed to ease the pain of GPU programming. However, with the demanding needs of more intensive workloads, it’s desirable to port GPU programs to more scalable distributed memory environment, such as multi-GPUs. To achieve this, programs need to be re-written with mixed programming models (e.g. CUDA and message passing). Programmers not only need to work carefully on workload distribution, but also on scheduling mechanisms to ensure the efficiency of the execution. In this paper, we studied the possibilities of automating the process of parallelization to multi-GPUs. Starting from a GPU program written in shared memory model, our framework analyzes the access patterns of arrays in kernel functions to derive the data partition schemes. To acquire the access pattern, we proposed a 3-tiers approach: static analysis, profile based analysis and user annotation. Experiments show that most access patterns can be derived correctly by the first two tiers, which means that zero efforts are needed to port an existing application to distributed memory environment. We use our framework to parallelize several applications, and show that for certain kinds of applications, CUDA-Zero can achieve efficient parallelization in multi-GPU environment.

关键词： CUDA parallelization data access pattern multi-GPU

PRINCIPLES OF RIVER TRAINING AND MANAGEMENT

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International Journal of Sediment research 2007年第4期22卷 247-262页

作者： Zhaoyin WANG1, Shimin TIAN2, Yujun YI3, and Guoan YU4 1 Prof., State Key Laboratory of Hydroscience and Engineering, tsinghua university, beijing, 100084, china 2 Ph. D., china institute of Water Resources and Hydro-Power research, beijing 100044, china. 3 Ph. D., State Key Laboratory of Hydroscience and Engineering, tsinghua university, beijing, 100084, china 4 Ph. D., State Key Laboratory of Hydroscience and Engineering, tsinghua university, beijing, 100084, china tsinghua Univ State Key Lab Hydrosci & Engn Beijing 100084 Peoples R China china Inst Water Resources & Hydropower Res Beijing 100044 Peoples R China

River regulation and river training have been performed for various purposes and negative effects have been shown in numerous cases. In some cases the negative effects are so serious that humans have to consider to "renaturalize" the regulated rivers. Only by using the strategy of integrated river management the diverse river uses and natural fluvial processes and ecological systems may be harmonized. Based on analysis of case studies and data collected from literatures this paper presents the concept of integrated river management and four principles of river training. The integrated river management comprises: 1) taking the watershed, upper stream basin including the tributaries, middle and lower reaches and the estuary as an integrated entity in the planning, design and management; and 2) mitigating or controlling the negative impacts on hydrology, erosion and sedimentation, fluvial processes, land use and river use, environment and ecology while in achieving economic benefit from water resources development, flood safety management and hydropower exploitation. River training and management should be in accordance with the four principles: 1) extending the duration of river water flowing on the continent, which may be achieved by extending the river course or reducing the flow velocity; 2) controlling various patterns of erosions and reducing the sediment transportation in the rivers; 3) increasing the diversity of habitat and enhancing the connectivity between the river and riparian waters; and 4) restoring natural landscapes.

关键词： River training Integrated river management Sediment Erosion control Ecological and landscape restoration

Application of intelligent control theory in AC servo system

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International Journal of Minerals,Metallurgy and Materials 1997年第3期11卷 43-45页

作者： WANG Zhiliang XIE Lun IJ Chongjian (information Engineering School, university of Science and technology beijing, beijing 100083, china) (Automation research institute of Metallurgical Industry, beijing 100071, china) Univ of Science and technology Beijing Beijing China

An AC servo system based on neuron control theory is presented. Experimental results show that the neuralcontrol mode doesn't need the Precise model of the system, therefore, it has many advantages, such as simple designand high response performance. The simulation research of the AC servo system which is non-linear, *** on neuro-fuzzy controller is done. The results of the simulation show that the performances of the system areconsiderably improved and it is one of the novel pathways to realize intelligent control of servo system.

关键词： servo system fuzzy control neural networks neuro-fuzzy networks

Cloning and characterization of 37 kDa laminin receptor precursor in pearl oyster,Pinctada fucata

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Progress in Natural Science:Materials International 2008年第2期18卷 233-238页

作者： Yaopeng Fu a,Liping Xie a,b,,Rongqing Zhang a,b,a institute of Marine Biotechnology,Department of Biological Sciences and Biotechnology,tsinghua university,beijing 100084,china b Protein Science Laboratory of the Ministry of Education,tsinghua university,beijing 100084,china institute of Marine Biotechnology Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Protein Science Laboratory of the Ministry of Education Tsinghua University Beijing 100084 China

A 1063 bp cDNA clone encoding a putative 37 kDa laminin receptor precursor (37 kDa LRP) is isolated from the mantle tissue of pearl oyster,Pinctada fucata. The amino acid sequence predicted from the cDNA sequence is 301 residues long,with a calculated molec-ular mass of 33.5 kDa. RT-PCR analysis shows that 37 kDa LRP mRNA is especially highly expressed in the mantle while widely expressed in several tissues. In situ hybridization analysis reveals that 37 kDa LRP is expressed in the outer epithelial cells of the mantle edge,suggesting its involvement in cell proliferation and secretion in P. fucata. The identification and characterization of 37 kDa LRP in the pearl oyster will help us to further understand the signal transduction in the processes of mantle epithelial cell proliferation and tissue formation.

关键词： 37 kDa laminin receptor precursor Mantle epithelial cell Pearl oyster

Multiparty simultaneous quantum identity authentication with secret sharing

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Science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer Science and technology,beijing university of technology,beijing 100022,china 2 State Key Laboratory of information Security (Graduate university of the Chinese Academy of Sciences),beijing 100049,china 3 School of Science,beijing university of Posts and Telecommunications,beijing 100876,china 4 institute of Electronic technology,information Engineering university,Zhengzhou 450004,china 5 Trusted Computing Laboratory,beijing university of technology,beijing 100022,china College of Computer Science technology Beijing University of Technology Beijing 100022 China State Key Laboratory of information Security [Graduate university of the Chinese Academy of Sciences] Beijing 100049 China School of Science Beijing University of Posts Telecommunications Beijing 100876 China institute of Electronic technology Information Engineering University Zhengzhou 450004 China Trusted Computing Laboratory Beijing University of Technology Beijing 100022 China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography

Generalized Self-Adaptive Genetic Algorithms

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 72-75页

作者： Bin Wu Xuyan Tu Jian Wu information Engineering School, university of Science and technology beijing, beijing 100083, china Department of information and Control Engineering, Southwest institute of technology, Mianyang 621002, china information Engineering School University of Science and Technology Beijing Beijing 100083 China Department of information and Control Engineering Southwest Institute of Technology Mianyang 621002 China

In order to solve the problem between searching performance and convergence of genetic algorithms, a fast genetic algorithm generalized self-adaptive genetic algorithm (GSAGA) is presented. (1) Evenly distributed initial population is generated. (2) Superior individuals are not broken because of crossover and mutation operation for they are sent to subgeneration directly. (3) High quality im- migrants are introduced according to the condition of the population schema. (4) Crossover and mutation are operated on self-adaptation. Therefore, GSAGA solves the coordination problem between convergence and searching performance. In GSAGA, the searching per- formance and global convergence are greatly improved compared with many existing genetic algorithms. Through simulation, the val- idity of this modified genetic algorithm is proved.

关键词： generalized self-adaptive genetic algorithm initial population immigration fitness function

Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation

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Science china Chemistry 2006年第2期49卷 186-192页

作者： HU Jun1, WANG Jianlong1,2 & CHEN Rong1 1. Laboratory of Environmental technology, institute of Nuclear Energy technology, tsinghua university, beijing 100084, china 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control, tsinghua university, beijing 100084, china Correspondence should be addressed to Wang Jianlong 1. Laboratory of Environmental technology Institute of Nuclear Energy Technology Tsinghua University Beijing 100084 China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control Tsinghua University Beijing 100084 China

The degradation of 4-chlorophenol (4-CP) by using gamma rays generated by a 60Co source in the presence of O3 was investigated. The radiolysis of 4-CP and the kinetics of 4-CP min-eralization were analyzed based on the determination of total organic carbon (TOC). The influence of initial 4-CP concentration and the free radicals scavengers (such as NaHCO3 and t-butanol) on the 4-CP degradation was also studied. The results showed that when the radiation rate was 336 Gy·min?1, 4-chlorophenol at concentration of 10 mg·L?1 could be completely degraded at the radiation dose of 2 kGy. The degradation of 4-chlorophenol could be described by a first-order reaction model, the rate constant of 4-CP degradation by combined ozonation and radiation was 0.1016 min?1, which was 2.4 times higher than the sum of radiation (0.0294 min?1) and ozonation (0.0137 min?1). It re-vealed that the combination of radiation and ozonation resulted in synergistic effect, which can re-markably increase the degradation efficiency of 4-CP.

关键词： radiolysis, 4-chlorophenol, priority pollutant, degradation, O3, synergistic effect, kinetics.

Kinetics study on the dissolution of UO_2 particles by microwave and conventional heating in 4 mol/L nitric acid

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Science china Chemistry 2008年第7期51卷 700-704页

作者： ZHAO YunFeng & CHEN Jing institute of Nuclear and New Energy technology, tsinghua university, beijing 102201, china institute of Nuclear and New Energy technology Tsinghua UniversityBeijing 102201China

The dissolution of UO2 particles in 4 mol·L-1 nitric acid medium at temperatures of 90-110℃ by mi- crowave heating and conventional heating has been investigated, respectively. It is found that the dissolution ratios of UO2 particles by microwave heating were 10%-40% higher than that by conven- tional heating. Kinetics research shows that the dissolution of UO2 particles in 4 mol·L-1 nitric acid is controlled by the diffusion control model for microwave heating and by the surface reaction control model for conventional heating. The diffusion control model for the dissolution of UO2 particles by mi- crowave heating could be explained by the diffuseness on the surface of UO2 particles.

关键词： uranium dioxide nitric acid dissolution microwave heating

The geometrical structure, electronic structure and magnetism of bimetallic Au_nM_2 (n=1, 2; M=Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd) clusters

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1011-1020页

作者： GU Juan1,2, WANG ShanYing2 & GOU BingCong1 1 Department of Physics, beijing institute of technology, beijing 100081, china 2 Department of Physics, tsinghua university, beijing 100084, china Department of Physics Beijing Institute of Technology Beijing 100081 China Department of Physics Tsinghua University Beijing 100084 China

The geometrical structure, stability, magnetism, and electronic structure of bimetallic clusters AuM2 and Au2M2, where M are 4d transition metal elements, are investigated systematically by using the first-principles method based on density functional theory. The calculation results show that there is a large amount of low-energy isomers with the very similar structure. AuM2 and Au2M2 clusters display dramatic magnetism. The magnetic moment of the 4d element is either enhanced or weakened with respect to the bulk value, which is largely dependent on the orbital exchange-splitting.

关键词： density functional theory first-principles cluster electronic structure magnetism