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Lattice Boltzmann Method used for the aircraft characteristics computation at high angle of attack

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Science china(Technological Sciences) 2010年第8期53卷 2068-2073页

作者： DU TeZhuan,LI XiangQun,ZHANG XiaLing&WANG YiWei College of Engineering,Peking university,beijing 100871,china 1. College of Engineering Peking University Beijing 100871 China

Traditional Finite Volume Method(FVM)and Lattice Boltzmann Method(LBM)are both used to compute the high angle attack aerodynamic characteristics of the benchmark aircraft model named *** though the software requires flow on the order of Matesting is satisfied,especially for the LBM which can produce perfect results at high angle *** can accurately capture the detail of flows because it is inherently time-dependent and parallel and suits large-scale computation very well.

关键词： LBM CFD high AOA

Carboxymethyl-β-Cyclodextrin for Chiral Separation of Basic Drugs by Capillary Elcctrophoresis

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Chinese Chemical Letters 1999年第10期10卷 831-832页

作者： Wei WANG Xiao Yun FU Yao Zu CHEN (analytical and testing center, Zhejiang {3.. Hangzhou 3.0027)(State Key Laboratory of Applied Organic Chemistry, Lanzhou {3., Lanzhou 73.000) analytical and testing center Zhejiang University Hangzhou 310027 China State Key Lab. of Appl. Organ. Chem. Lanzhou University Lanzhou 730000 China

Four basic drugs were separated by capillary electrophoresis (CE) usingcarboxymethyl-β-yclodextrin (CM-0-CD) as chiral selector. The effects of CM-β-CDconmptration, applied voltage. operation temperature were investigated. Under the selectedconditions. norephedrine. ofloxacin. terbutaline and chlorpheniramine were enantiomerallybaieline-separated using H3.O4-triethanolamine buffer at PH 3.containing 10, 5.5, 2. 2mmol/LCM-β-CD respectively.

关键词： Capillary electrophoresis chiral separation, carboxymethyl-β-cyclodextrin. basicdrugs.

Remarks on the bounds for cryptanalysis of low private key RSA

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Progress in Natural Science:Materials International 2009年第10期19卷 1327-1331页

作者： Haijian Zhou a,Ping Luo b,Daoshun Wang a,Yiqi Dai a a Department of Computer Science and Technology,Tsinghua university,beijing 100084,china b School of Software,Tsinghua university,beijing 100084,china [a]Department of Computer Science and Technology Tsinghua University Beijing 100084 China [b]School of Software Tsinghua University Beijing 100084 China

Boneh and Durfee have developed a cryptanalytic algorithm on low private key *** algorithm is based on lattice basis reduction and breaks RSA with private key d < N0:*** on,an improved version by Blmer and May enhan... 详细信息

Boneh and Durfee have developed a cryptanalytic algorithm on low private key *** algorithm is based on lattice basis reduction and breaks RSA with private key d analytical model,with which the theoretical upper bound on d is modified to approximately d < N0:277 for ordinary RSA systems with a 1024-bit public key eN;eT.

关键词： RSA Cryptanalysis Low private key Lattice basis reduction

analytical-VARIATIONAL METHOD OF SOLUTION FOR FINITE MONOLITHIC PLATE WITH HOLE-EDGE CRACKS

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Chinese Journal of Aeronautics 1993年第3期 178-185页

作者： Fu Dong-shan,Zhang Xing (beijing university of Aeronautics and Astronautics,beijing,{3.,100083.

Total field expressions of stress and displacement components in a finite monolithicplate with double linear hole edge crack are derived by means of method of functions ofcomplex variables, and all of the basic equations, boundary conditions of crack surfacesand single-valued condition of displacements about multi-connected region are satisfiedexactly. The stress intensity factors are solved by means of variational method to satisfythe other boundary conditions. In the variational equations there are only line integrals andno area integrals. The convergency is very rapid and the method is time-saving. Then,systematical results are presented by curves of nondimensional stress intensity factor versusnondimensional crack lengths with nondimensional hole radii and aspect ratios asparameters. Finally, the analytical-variational method is extended to the case withoutcracks, the convergency is nice also and systematical results are provided by curves ofstress concentration factors versus nondimensional hole radii with aspect ratios asparameters.

关键词： analytical-VARIATIONAL METHOD OF SOLUTION FOR FINITE MONOLITHIC PLATE WITH HOLE-EDGE CRACKS EDGE

Cavitation-erosion resistance of arc ion-plated (Ti, Cr) N coatings

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Science china Mathematics 2001年第S1期44卷 369-374页

作者： PAN Guoshun YANG Wenyan National Tribology Laboratory, Tsinghua university, beijing 100084, china Tsinghua Univ Natl Tribol Lab Beijing 100084 Peoples R China

The cavitation-erosion behavior of (Ti,Cr)N multi-component coatings produced by arcion-plating on grey cast iron was studied by using an ultrasonic cavitation -erosion testing appara-tus and scanning electron microscopy. The test results indicated that surface roughness of thesubstrate, surface morphology of the coating, substrate bias voltage and the thickness of the coat-ing had certain influence on the erosion rate. Arc ion-plated (Ti,Cr)N multi-component coatingsshowed better cavitation -erosion resistance than single component coatings because of highermicrohardness and good adhesion.

关键词： cavitation-erosion ion plating (Ti, Cr) N coatings grey cast iron

analytical MODEL OF HELICOPTER AIRCOMBAT AND MATHEMATICINVERSE SOLUTION

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Chinese Journal of Aeronautics 1995年第4期8卷 237-246页

作者： Cao Yihua(Institute of Fluid Mechanics, beijing university of Aeronauticsand Astronautics, beijing, {3., 100083.

in helicopter air combat, the helicopter must have the maneuverability andagility to gain a firing position first and its weapon systems must be able to get firstround hits for successful air combat. In an attempt to address the questions, a generalanalytical model of helicopter / annament system combat is established. Taking the hel-icopter air combat at short range as an example, the kinematic law of a turreted gun iscalculated. The development and results here may provide a referable basis for maxinuz-ing the hit probability of the gun in air firing.

关键词： helicopters maneuvers flight combat

Experimental investigation of high temperature thermal contact resistance with interface material

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Theoretical & Applied Mechanics Letters 2011年第5期1卷 41-44页

作者： Xiaoping Zheng1,Donghuan Liu,2,3.Dong Wei,4 and Xinchun Shang 2,3.1) Applied Mechanics Laboratory,Department of Engineering Mechanics,Tsinghua university,beijing 100084,china 2) Department of Applied Mechanics,university of Science & Technology beijing,beijing 100083.china 3. National center for Materials Service Safety,university of Science & Technology beijing,beijing 100083.china 4) china Aerodynamics Research and Development center,Mianyang 621000,china china Aerodynamics Research and Development center Mianyang 621000 China

Thermal contact resistance plays a very important role in heat transfer efficiency and thermomechanical coupling response between two materials,and a common method to reduce the thermal contact resistance is to fill a soft interface material between these two materials.A testing system of high temperature thermal contact resistance based on INSTRON 8874 is established in the present paper,which can achieve 600 C at the *** on this system,the thermal contact resistance between superalloy GH600 material and three-dimensional braid C/C composite material is experimentally investigated,under different interface pressures,interface roughnesses and temperatures,*** the same time,the mechanism of reducing the thermal contact resistance with carbon fiber sheet as interface material is experimentally *** show that the present testing system is feasible in the experimental research of high temperature thermal contact resistance.

关键词： thermal contact resistance interface material experimental research high temperature alloy C/C composite material

Analysis on background magnetic field to generate eddy current by pulsed gradient of permanent-magnet MRI

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Science china(Technological Sciences) 2010年第4期53卷 886-891页

作者： ZU DongLin,HONG LiMing,CAO XueMing & TANG Xin Institute of Heavy Ion Physics,beijing City Key Laboratory of Medical Physics and Engineering,School of Physics,Peking university,beijing 100871,{3. 1. Institute of Heavy Ion Physics Beijing City Key Laboratory of Medical Physics and Engineering School of Physics Peking University Beijing 100871 China

In this paper the analytical expressions for the magnetic field H and induction B in iron-pole plates generated by MRI gradient coil are given using line-current and the multilayer dielectric plate model with the mirror-image *** current emanates from the magnetic flux in the iron-pole *** order to fully suppress the eddy current,this magnetic flux should be fully *** research results indicate the magnetic permeability of the resist-eddy plate must be bigger than that of magnetic pole material,*** iron,and that the resist-eddy plate should be thick enough to be far away from its magnetic saturation.

关键词： MRI suppress eddy current gradient coil resist-eddy plate mirror-image method

Theoretical analysis of transcranial Hall-effect stimulation based on passive cable model

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Chinese Physics B 2015年第12期24卷 373-378页

作者：袁毅李小俚 Institute of Electrical Engineering Yanshan University State Key Laboratory of Cognitive Neuroscience and Learning & IDG Mc Govern Institute for Brain Research Beijing Normal University center for Collaboration and Innovation in Brain and Learning Sciences Beijing Normal University

Transcranial Hall-effect stimulation（THS） is a new stimulation method in which an ultrasonic wave in a static magnetic field generates an electric field in an area of interest such as in the brain to modulate neuronal activities. However, the biophysical basis of simulating the neurons remains unknown. To address this problem, we perform a theoretical analysis based on a passive cable model to investigate the THS mechanism of neurons. Nerve tissues are conductive; an ultrasonic wave can move ions embedded in the tissue in a static magnetic field to generate an electric field（due to Lorentz force）.In this study, a simulation model for an ultrasonically induced electric field in a static magnetic field is derived. Then,based on the passive cable model, the analytical solution for the voltage distribution in a nerve tissue is determined. The simulation results showthat THS can generate a voltage to stimulate neurons. Because the THS method possesses a higher spatial resolution and a deeper penetration depth, it shows promise as a tool for treating or rehabilitating neuropsychiatric disorders.

关键词： Hall-effect stimulation passive cable model neurons