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science china(Physics,Mechanics & Astronomy) 2009年第1期52卷 124-138页

作者： LI ZhiHui1,2 & ZHANG HanXin1 1 National Laboratory for Computational fluid dynamics, Beijing 100083, china 2 china Aerodynamics research and Development center, Hypervelocity Aerodynamics Institute, Mianyang 621000, china National Laboratory for Computational fluid dynamics Beijing China china Aerodynamics research and Development center Hypervelocity Aerodynamics Institute Mianyang China

The Boltzmann simplified velocity distribution function equation describing the gas transfer phenomena from various flow regimes will be explored and solved numerically in this study. The discrete velocity ordinate method of the gas kinetic theory is studied and applied to simulate the complex multi-scale flows. Based on the uncoupling technique on molecular movement and colliding in the DSMC method, the gas-kinetic finite difference scheme is constructed to directly solve the discrete velocity distribution functions by extending and applying the unsteady time-splitting method from computational fluid dynamics. The Gauss-type discrete velocity numerical quadrature technique for different Mach number flows is developed to evaluate the macroscopic flow parameters in the physical space. As a result, the gas-kinetic numerical algorithm is established to study the three-dimensional complex flows from rarefied transition to continuum regimes. The parallel strategy adapted to the gas-kinetic numerical algorithm is investigated by analyzing the inner parallel degree of the algorithm, and then the HPF parallel processing program is developed. To test the reliability of the present gas-kinetic numerical method, the three-dimensional complex flows around sphere and spacecraft shape with various Knudsen numbers are simulated by HPF parallel computing. The computational results are found in high resolution of the flow fields and good agreement with the theoretical and experimental data. The computing practice has confirmed that the present gas-kinetic algorithm probably provides a promising approach to resolve the hypersonic aerothermodynamic problems with the complete spectrum of flow regimes from the gas-kinetic point of view of solving the Boltzmann model equation.

关键词： Boltzmann model equation kinetic theory velocity distribution function discrete velocity ordinate technique hypersonic flow parallel computing numerical methods

Significance of stress on mobilization of ore-forming materials

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Chinese science Bulletin 1999年第S2期44卷 139-141页

作者： MA Rui and JIANG Qigang research center of Metamorphic dynamics of Changchun university of science and technology, Changchun 130061, china research center of Metamorphic dynamics Changchun University of Science and Technology Changchun 130061 China

METALLOGENIC processes represent migration and concentration of useful elements, which are controlled by a number of factors. Among varied geological factors, stress is very improtant. Stress could not only causethe fracture and deformation, but also is closely related to the mobilization and migration of ore-formingmaterials, especially for hydrothermal deposits. Varied experiments have been carried out to showthe above phenomenon. The sample is carbonaceous slate collected from the Taiyangding Group of the Nuo ’ ergai area,Sichuan Province. The rock is fresh, creckless, containing 40×10-9 of gold and high content of organiccarbon. Under a microscope, it is black. A group of state cleavage is observed, fine quartz and uniformily distributed carbonaceous materials. The quartz is<0.01 mm in diametre. Using high temperature

关键词： stress mobilization ore-formmg material.

A relative local variational principle for topological pressure

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science china Mathematics 2010年第6期53卷 1491-1506页

作者： MA XianFeng1,CHEN ErCai2,3,& ZHANG AiHua2,4 1Department of Mathematics,East china university of science and technology,Shanghai 200237,china 2School of Mathematics and Computer science,nanjing Normal university,nanjing 210097,china 3center of Nonlinear science,nanjing university,nanjing 210093,china 4College of Mathematics and Physics,nanjing university of Posts and Telecommunications,nanjing 210046,china Department of Mathematics East China University of Science and Technology Shanghai China School of Mathematics and Computer science Nanjing Normal University Nanjing China center of Nonlinear science Nanjing University Nanjing China College of Mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing China

We define the relative local topological pressure for any given factor map and open cover,and prove the relative local variational principle of this *** precisely,for a given factor map π:(X,T)→(Y,S) between two topological dynamical systems,an open cover U of X,a continuous,real-valued function f on X and an S-invariant measure ν on Y,we show that the corresponding relative local pressure P(T,f,U,y) satisfies sup μ∈M(X,T){ hμ(T,U|Y)+∫X f(x)dμ(x) :πμ=ν}=∫Y P(T,f,U,y)dν(y),where M(X,T) denotes the family of all T-invariant measures on ***,the supremum can be attained by a T-invariant measure.

关键词： pressure conditional entropy relative local variational principle

Local segment-shared protection based on source egress gateway selection for multi-domain optical mesh networks

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science china(Information sciences) 2011年第2期54卷 227-235页

作者： ZHANG ShengFeng1,3, PENG YunFeng1,2, DU Shu1, YANG XiaoLong1,2 & LONG KePing1,2 1research center for Optical Internet and Mobile Information Networks, university of Electronic science and technology of china, Chengdu 611731, china 2Institute of Advanced Network technology and New Serives (ANTS), university of science and technology Beijing, Beijing 100083, china 3research center for Optical Internet Networks, Chongqing university of Posts and Telecommunications, Chongqing 400065, china research center for Optical Internet and Mobile Information Networks University of Electronic Science and Technology of China Chengdu China research center for Optical Internet Networks Chongqing University of Posts and Telecommunications Chongqing China Institute of Advanced Network technology and New Serives (ANTS) University of Science and Technology Beijing Beijing China

Survivability for multi-domain optical networks is becoming a key parameter due to expanding network. In order to provide the shared-path-protected lightpath in multi-domain optical mesh networks, we propose a protection solution, called GSLSSP. A new source egress gateway selecting mechanism is adopted in this solution. For each connection request, this mechanism can enable the source node to select a better egress gateway node to the destination domain and compute one inter-domain working path near the optimal path with the cooperating of this gateway node, under scalability and domain privacy constraint of multi-domain networks. And then one intra-domain link-disjoint local segment-backup path for each working-segment path is computed out in each single-domain passed by the working path. Simulation evaluation shows that the proposed scheme can provide 100% protection ability for multiple failures. Besides, it is effective in multi-domain path protection with more efficient resource utilization, lower blocking probabilities and less inter-domain cost than other schemes.

关键词： survivability optical mesh networks multi-domains multiple failures segment-shared protection

Online application of automatic surface quality inspection system to finishing line of cold rolled strips

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Journal of university of science and technology Beijing 2003年第4期10卷 38-41页

作者： Hao Sun, Ke Xu, and Jinwu XuNational Engineering research center of Advanced Rolling, university of science and technology Beijing, Beijing 100083, china Natl. Eng. Res. Ctr. of Adv. Rolling Univ. of Sci. and Technol. Beijing Beijing 100083 China

An automatic surface quality inspection system installed on a finishing lineof cold rolled strips is introduced. The system is able to detect surface defects on cold rolledstrips, such as scratches, coil breaks, rusts, roll imprints, and so on. Multiple CCD area scancameras were equipped to capture images of strip surface simultaneously. Defects were detectedthrough 'Dark-field illumination' which is generated by LED illuminators. Parallel computationtechnique and fast processing algorithms were developed for real-time data processing. Theapplication to the production line shows that the system is able to detect defects effectively.

关键词： surface inspection cold rolled strip finishing line CCD cameras imageprocessing

P2P traffic optimization

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science china(Information sciences) 2012年第7期55卷 1475-1492页

作者： ZHANG GuoQiang 1,2 ,TANG MingDong 3 ,CHENG SuQi 2,4 ,ZHANG GuoQing 2 ,SONG HaiBin 5 ,CAO JiGuang 6 & YANG Jing 7 1 School of Computer science and technology,nanjing Normal university,nanjing 210046,china 2 Institute of Computing technology,Chinese Academy of sciences,Beijing 100190,china 3 School of Computer science and Engineering,Hunan university of science and technology,Xiangtan 411201,china 4 Graduate university of Chinese Academy of sciences,Beijing 100190,china 5 nanjing R&D center,Huawei Technologies,nanjing 210012,china 6 china Academy of Telecommunication research of MIIT,Beijing 100191,china 7 china Mobile research Institute,Beijing 100053,china School of Computer science and technology Nanjing Normal University Nanjing China Institute of Computing technology Chinese Academy of Sciences Beijing China School of Computer science and Engineering Hunan University of Science and Technology Xiangtan China Graduate university of Chinese Academy of sciences Beijing China nanjing R&D center Huawei Technologies Nanjing China china Academy of Telecommunication research of MIIT Beijing China china Mobile research Institute Beijing China

Peer-to-peer (P2P) based content distribution systems have emerged as the main form for content distribution on the Internet,which can greatly reduce the distribution cost of content providers and improve the overall system ***,the mismatch between the overlay and underlay networks causes large volume of redundant traffic,which intensifies the tension between P2P content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2P *** paper surveys the state-of-art P2P traffic optimization technologies from three perspectives:P2P cache,locality-awareness and data *** details,comparison between these technologies and their applicabilities are presented,followed by a discussion of the issues that remain to be addressed and the direction of future content distribution research.

关键词： P2P traffic localization P2P traffic optimization P2P cache locality-awareness network coding content-centric network

Stabilization for discrete-time fuzzy systems with Takagi-Sugeno's models:reduce the complexity

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science china(Information sciences) 2010年第12期53卷 2506-2513页

作者： WANG LiKui 1 & LIU XiaoDong 2 1 School of Mathematics and Information science,Nanchang Hangkong university,Nanchang 330063,china 2 research center of Information and Control,Dalian university of technology,Dalian 116024,china School of Mathematics and Information science Nanchang Hangkong University Nanchang China research center of Information and Control Dalian University of Technology Dalian China

The problem of sate feedback control for discrete-time fuzzy systems with Takagi-Sugeno's models is investigated to reduce the computational burden.A stabilization condition is obtained by applying a new Lyapunov *** is shown that our new theorem is equivalent to an existing result in guaranteeing the stability of the fuzzy system but consumes less computational time than the *** effectiveness and the superiority of the proposed design approach are demonstrated by an example borrowed from the literature.

关键词： Takagi-Sugeno’s fuzzy model non-quadratic Lyapunov function linear matrix inequality

A Method for Generating Super Large Fractal Images Useful for Decoration Art

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Communications in Nonlinear science and Numerical Simulation 1996年第3期1卷 24-27页

作者： Huajie LIU Jun LUO(research center for science & Society Peking university, P.R.china)(Department of Computer science & technology, Peking university, P.R.china) research center for science & Society Peking University P.R. China

Many authors have reported the techniques to iterate nonlinear equations oncomplex plane, but generally, the sise of image calculated by usual VGA style (640×480) istoo small to fit the needs for high quality publications or decorative patterus. We describea universal method for generating and storing (in *.GIF format) fractal forge large enoughas you need, such as an wie 5000×5000 256-color(25,000, 74 bytes 23.8MB), whichcan thoroughly display the intricate beauty of fractals.

关键词： super large fractal images iteration decoration art

Preparation of PFSA/PSf hollow fiber composite membranes with recovered PFSA for the pervaporation separation of EtOH/H_2O

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science china Chemistry 2010年第1期53卷 273-280页

作者： LANG WanZhong1,2,TONG Wei2,XU ZhenLiang2 & GUO YaJun1 1Department of Chemistry,Shanghai Normal university,Shanghai 200234,china 2Chemical Engineering research center,East china university of science and technology,Shanghai 200237,china Department of Chemistry Shanghai Normal University Shanghai China Chemical Engineering research center East China University of Science and Technology Shanghai China

Perfluorosulfonic acid/Polysulfone(PFSA/PSf) hollow fiber composite membranes have been prepared by dip-coating method using PSf ultrafiltration(UF) membrane as substrate with recovered *** composite membranes were applied to the pervaporation separation of 95% ethanol(EtOH)/H2O *** images show that the thickness of the PFSA skin layer of the composite membranes is about 2 μm,much thinner than those of other PFSA composite membranes revealed in the *** of annealing temperature,coating solution concentration and counter-ions of PFSA on the pervaporation performances of the composite membranes were *** total flux decreases and separation factor increases with the increase of annealing *** highest permeation flux of 3230 g m-2 h-1 and a separation factor of 5.4 is obtained for the composite membrane annealed at 80°*** lowest permeation flux of 396 g m-2 h-1 and a separation factor of 27.7 is obtained for the composite membrane annealed at 160°*** permeation performances of the PFSA/PSf composite membrane are evidently influenced by the counter-ions of *** flux sequence of the PFSA/PSf composite membranes with different counter-ions is H+>Li+>Ca2+>Mg2+>Na+>K+>Ba2+>Fe3+>Al3+,and the separation factor sequence is H+2+2+2+Na+>K+.There are very little variations of △Eapp values between the composite membranes with three divalent counterions(Mg2+,Ca2+ and Ba2+),and the △Eapp values of the composite membranes with two trivalent counterions(Fe3+ and Al3+) are relatively high.

关键词： pervaporation hollow fiber composite membrane perfluorslulfonic acid(PFSA) ethanol(EtOH)/H2O mixture