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DISPERSION COMPARISONS OF TWO PROBABILITY VECTORS UNDER MULTINOMIAL SAMPLING

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Acta Mathematica Scientia 2010年第3期30卷 907-918页

作者：熊世峰李国英 academy of Mathematics and systems science Chinese Academy of Sciences

We consider testing hypotheses concerning comparing dispersions between two parameter vectors of multinomial distributions in both one-sample and two-sample cases. The comparison criterion is the concept of Schur majorization. A new dispersion index is proposed for testing the hypotheses. The corresponding test for the one-sample problem is an exact test. For the two-sample problem, the bootstrap is used to approximate the null distribution of the test statistic and the p-value. We prove that the bootstrap test is asymptotically correct and consistent. Simulation studies for the bootstrap test are reported and a real life example is presented.

关键词： Multinomial distribution dispersion diversity bootstrap hypothesis testing majorization

ON THE CENTRAL RELAXING SCHEME Ⅱ: systems OF HYPERBOLIC CONSERVATION LAWS

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Journal of Computational Mathematics 2001年第6期19卷 571-582页

作者： Hua-zhong Tang (School of Mathematical sciences, Peking University, beijing 100871, china) (LSEC,ICMSEC academy of Mathematics and systems sciences, chinese academy of sciences, beijing 100080, china) School of Mathematical sciences Peking University Beijing 100871 China

This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced to approximate system of conservation laws in curvilinear coordinates. Based on them, the semi-implicit relaxing schemes are con- structed as in [6, 12] without using any linear or nonlinear Riemann solvers. Numerical experiments for one-dimensional and two-dimensional problems are presented to demon- strate the performance and resolution of the current schemes.

关键词： Hyperbolic conservation laws The relaxing system The central relaxing schemes The Euler equations.

Boundedness of Solutions in Asymmetric Oscillations via the Twist Theorem

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Acta Mathematica Sinica,English Series 2001年第2期17卷 313-318页

作者： Yi Qian WANG institute of Mathematics. academy of Mathematics and systems sciences. chinese academy of science, beijing 100080 P. R. china institute of Mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Science Beijing 100080 P. R. China

In this paper we consider the boundedness of all the solutions for the equation x'+ax^+ -bx^-=f(t). where f(t) is a smooth 2π-periodic function, a and b are positive constants (a≠b).

关键词： Boundedness Asymmetric Canonical transformation Twist theorem

A new transient stability margin based on dynamic security region and its applications

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science china(Technological sciences) 2008年第6期51卷 751-760页

作者： XUE AnCheng1, 2 & MEI ShengWei1 1 State Key Lab of Power systems, Department of Electrical Engineering, Tsinghua University, beijing 100084, china 2 Key Lab of systems and Control, institute of systems science, chinese academy of sciences, beijing 100190, china State Key Lab of Power systems Department of Electrical Engineering Tsinghua University Beijing China Key Lab of systems and Control Institute of Systems Science Chinese Academy of Sciences Beijing China

A new transient stability margin is proposed based on a new expression of dynamic security region (DSR) which is developed from the existing expression of DSR. Applications of the DSR based transient stability margin to contingency ranking and screening are discussed. Simulations in the 10-machine 39-bus New England system are performed to show the effectiveness of the proposed DSR based tran-sient stability margin.

关键词： dynamic security region (DSR) transient stability margin contingency screening

Research of the Gas-solid Flow Character Based on the DEM Method

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Journal of Thermal science 2011年第6期20卷 521-526页

作者： Xueyao Wang and Yunhan Xiao Research Center for Clean Energy and Power,chinese academy of sciences Key Laboratory of Advanced Energy and Power,chinese academy of sciences (institute of Engineering Thermophysics),beijing,100190,china Research Center for Clean Energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China

Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM).Euler method and Lagrange method are employed to deal with the gas phase and solid phase *** collided force among particles,striking force between particle and wall,drag force,gravity,Magnus lift force and Saffman lift force are considered when establishing the mathematic ***-sphere model is used to describe the collision of *** addition,the Euler method is also used for modeling the solid phase to compare with the results of *** flow patterns,particle mean velocities,particles' diffusion and pressure drop of the bed under typical operating conditions are *** results show that the DEM method can describe the detailed information among particles,while the Euler-Euler method cannot capture the micro-scale *** matter which method is used,the diffusion of particles increases with the increase of gas *** the gathering and crushing of particles cannot be simulated,so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is *** addition,it is shown by DEM method,with strengthening of the carrying capacity,more and more particles can be schlepped upward and the dense suspension upflow pattern can be ***,the results given by the Euler-Euler method are not consistent with the real situation.

关键词： DEM gas-solid flow numerical simulation

Maximal effective baseline for polarimetric interferometric SAR forest height estimation

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science china(Information sciences) 2012年第4期55卷 867-876页

作者： ZHOU YongSheng 1,2,3,HONG Wen 1,2,WANG YanPing 1,2 & WU YiRong 1,2 1 National Key Laboratory of science &Technology on Microwave Imaging,beijing 100190,china 2 institute of Electronics,chinese academy of sciences,beijing 100190,china 3 academy of Opto-Electronics,chinese academy of sciences,beijing 100094,china National Key Laboratory of science & Technology on Microwave Imaging Beijing China institute of Electronics Chinese Academy of Sciences Beijing China academy of Opto-Electronics Chinese Academy of Sciences Beijing China

The concepts of critical baseline and maximal effective baseline have been defined for interferometric SAR (InSAR) DEM application based on the spatial decorrelation (which is a function of baseline).This paper puts forward these two concepts to polarimetric interferometric SAR (Pol-InSAR) forest height estimation *** application makes use of volume decorrelation,which is also a function of *** both the spatial decorrelation and volume decorrelation are considered to determine Pol-InSAR critical and maximal effective *** various decorrelation effects are *** the calculation formula of Pol-InSAR maximal effective baseline are presented and compared to that of *** validation,RVoG-based and PolSARpro-based simulation data and DLR ESAR data are *** concept of Pol-InSAR maximal effective baseline is of practical significance in selection of Pol-InSAR image pairs as well as in the design of further Pol-InSAR systems.

关键词： Pol-InSAR maximal baseline forest height estimation

IL-8-induced L-selectin shedding regulates its binding kinetics to PSGL-1

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chinese science Bulletin 2009年第16期54卷 2786-2793页

作者： JIA XiaoLing1,2,3, CHEN Juan1,2 & LONG Mian1,2 1 National Microgravity Laboratory, institute of Mechanics, chinese academy of sciences, beijing 100190, china 2 Center of Biomechanics and Bioengineering, institute of Mechanics, chinese academy of sciences, beijing 100190, china 3 School of Biological science and Medical Engineering, Beihang University, beijing 100083, china National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing China Center of Biomechanics and Bioengineering Institute of Mechanics Chinese Academy of Sciences Beijing China School of Biological science and Medical Engineering Beihang University Beijing China

L-selectin plays a crucial role in inflammation cascade by initiating the tethering and rolling of leukocytes on endothelium wall. While many L-selectin molecules are rapidly shed from the cell surface upon activation, the remaining membrane-anchored L-selectin may still play an important role in regulating leukocyte rolling and adhesion with different binding kinetics. Here we developed an in vitro model to activate Jurkat cells via interlukin-8 (IL-8) and quantified the two-dimensional (2D) binding kinetics, using a micropipette aspiration assay, of membrane-anchored L-selectin to P-selectin glycoprotein ligand 1 (PSGL-1) ligand coupled onto human red blood cells (RBCs). The data indicated that L-selectin shedding reduced the amount of membrane-anchored L-selectin and lowered both its reverse and forward rates. These results suggested that the rolling dynamics of activated leukocytes was determined by two opposite impacts: reducing the surface presentation would enhance the rolling but lowering the kinetic rates would decrease the rolling. This finding provides a new insight into under-standing how L-selectin shedding regulates leukocyte rolling and adhesion.

关键词：结合动力学选择素配体白细胞介素8 Jurkat细胞诱导细胞表面微管吸吮

A NEW STABILIZED FINITE ELEMENT METHOD FOR SOLVING THE ADVECTION-DIFFUSION EQUATIONS

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Journal of Computational Mathematics 2002年第1期20卷 57-64页

作者： Huo-yuan Duan (institute of Mathematics, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080, china) institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences 北京 100080

Focuses on a study on the development of a stabilized finite element method for solving the advection-diffusion equations with a zero Dirichlet boundary condition. Problem formulation; Error analysis.

关键词： advection-diffusion equation stabilized finite element method

^(40)Ar/^(39)Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

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science china Earth sciences 2004年第9期47卷 794-803页

作者： ZHANG Yueqiao1, CHEN Wen2, 3 & YANG Nong1 1. institute of Geomechanics, chinese academy of Geological sciences, beijing 100081, china 2. institute of Geology, chinese academy of Geological sciences, beijing 100037, china 3. institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, china institute of Geomechanics Chinese Academy of Geological Sciences Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Based on field geological survey, structural measurements and classical Ar/Ar dating of mica, biotite and K-feldspar, we obtain cooling ages for Miocene left-lateral shear along the Xianshuihe fault zone. The results document two thermal events during the sinistral shear. The early event (12-10 Ma) corresponds to rapid cooling of the Zheduoshan granitic massif from above 700℃ to below 350℃. The late event (5-3.5 Ma) corresponds to cooling of granites intruded along the eastern side of the fault zone. These dating results provide important thermochronological constraint on the timing of late Cenozoic eastward extrusion of the Chuan-Dian Block in the SE Tibetan margin.

关键词： Xianshuihe fault zone, Zheduoshan granitic massif, sinistral shear deformation, 40Ar/39Ar dating, late Cenozoic.