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

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 {2. 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

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RRM:An incentive reputation model for promoting good behaviors in distributed systems

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Science in china(Series F) 2008年第11期51卷 1871-1882页

作者： ZHANG Hong1,2.DUAN HaiXin1,3 & LIU Wu1,3 1 Tsinghua national Laboratory for Information Science and Technology,Tsinghua University,beijing 100084,{2. 2.Department of Computer Science and Technology,Tsinghua University,beijing 100084,{2. 3 Network research center,Tsinghua University,beijing 100084,{2. 1. Tsinghua national Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China 2. Department of Computer Science and Technology Tsinghua University Beijing 100084 China 3. Network research center Tsinghua University Beijing 100084 China

Reputation systems represent soft security mechanisms that complement traditional information security mechanisms. They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors. This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model （RRM） for the distributed reputation systems. The objective of this reputation model is not only to encourage the users to provide good services and, therefore, to maximize the probability of good transaction outcomes, but also to punish those adverse users who are trying to manipulate the application systems. The simulation results indicate that the proposed reputation model （RRM） could effectively resist against the common adverse behaviors, while protecting the profits of sincere users from being blemished by those adversaries.

关键词： reputation model distributed system trust soft security

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The theoretical research of basic function method in incompressible viscous flow and its simulations in three-dimensional aneurysms

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 909-918页

作者： SHEN Fang1 & WU WangYi2.1 State Key Laboratory for Space Weather, center for Space Science and Applied research, Chinese Academy of Sciences, {2., china 2.State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and engineering Science, Peking University, beijing 100871, china 1. State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and engineering Science Peking University Beijing 100871 China

Basic function method is developed to treat the incompressible viscous flow. Artificial compressibility coefficient, the technique of flux splitting method and the combination of central and upwind schemes are applied to construct the basic function scheme of trigonometric function type for solving three-dimensional incompressible Navier-Stokes equations numerically. To prove the method, flows in finite-length-pipe are calculated, the velocity and pressure distribution of which solved by our method quite coincide with the exact solutions of Poiseuille flow except in the areas of entrance and exit. After the method is proved elementary, the hemodynamics in two-and three-dimensional aneurysms is researched numerically by using the basic function method of trigonometric function type and unstructured grids generation technique. The distributions of velocity, pressure and shear force in steady flow of aneurysms are calculated, and the influence of the shape of the aneurysms on the hemodynamics is studied.

关键词： basic function unstructured grid aneurysm viscous incompressible flow artificial compressibility flux splitting

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Exotic structure of the third excited state in^(2.)Na

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Chinese Science Bulletin 2005年第23期50卷 2677-2680页

作者： LI Xihan1,2.3, LIANG Yujie1,2.3, DENG Fuguo1,2.3, LIU Zuhua1,4 & ZHOU Hongyu1,2.3 1. Key Laboratory of Beam Technology and Material Modification of Minister of Education, beijing Normal University, beijing 100875, {2. 2. Institute of Low Energy Nuclear Physics, and Department of Material Science and engineering, beijing Normal University, beijing 100875, {2. 3. beijing Radiation center, beijing 100875, {2. 4. {2. Institute of Atomic Energy, beijing 102.13, {2. Key Laboratory of Beam Technology and Material Modification of Minister of Education Beijing Normal University Beijing 100875 China Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing 100875 China beijing Radiation center Beijing 100875 China china Institute of Atomic Energy Beijing 102413 China

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (1/2. of the third excited state in 2.Na are calcu- lated by means of asymptotic normalization coefficie... 详细信息

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (2.1/2. of the third excited state in 2.Na are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73% and 2.1/2.5.2. fm respectively. The P value and the contribution of the asymptotic part to the 2.1/2.are compared with those of several other low energy states in 2.Na. It is found that the valence particle in the third excited state has an obvious larger P than those of other states. The density distribution of the valence proton in this state is also compared with the nucleons in the nuclear core 2.Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 2.Na is a proton halo state.

关键词：钠第三激发态外部结构有效半径密度分布渐近标准化系数

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A novel method for evaluating and improving the 1H-MRSI glioma data quality

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Progress in Natural Science:Materials International 2005年第8期15卷 765-768页

作者： YUAN Kehong 1,2. LU Hongyu2. BAO Shanglian2., CHEN Qiansheng1, LI Shaowu3 and DUAN Chaijie2.1. Key Laboratory of Pure and Applied Mathematics, School of Mathematical Sciences, beijing 100871, china 2. The {2. center for Tumor Diagnosis and Therapeutical Physics & the beijing Key Laboratory of Medical Physics and engineering, Peking University, beijing 100871, china 3. The Tian Tan Hospital, beijing 100050, china) Key Laboratory of Pure and Applied Mathematics School of Mathematical Sciences Beijing 100871 China. The research center for Tumor Diagnosis and Therapeutical Physics & the {2. Key Laboratory of Medical Physics and engineering Peking University Beijing 100871 China. The Tian Tan Hospital Beijing 100050 China

Metabolic information obtained by proton magnetic resonance spectroscopic imaging (1H-MRSI) has been approved to be a powerful tool to identify either benign or malignant glioma, as well as to confirm the tumor level. However, 1H-MRSI data are affected by various factors, such as the thermal noise, eddy currents, susceptibility artifacts, and rigid body motion. To get accurate quantitative metabolic information, the key problem is to assess the 1H-MRSI data quality. In this paper, we introduce a new evaluating system to filter the data, and a new method, called wavelet denoising method, to improve the data quality under the evaluating system. Experimental results on 1H-MRSI glioma data demonstrate that preprocessing is prerequisite and the proposed algorithm with evaluating system is effective.

关键词： 1H-MRSI evaluating system glioma data quality wavelet denoising

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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 {2. 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

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One-pot synthesis of crystalline SnO_2.nanoparticles and their low-temperature ethanol sensing characteristics

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1601-1605页

作者： CHEN YuJin1,2.3,ZHU ChunLing4,WANG LiJiao3 & WANG TaiHong2.1 School of Materials Science and engineering,beijing Institute of Technology,beijing 100081,china 2.Micro-Nano Technologies research center,Hunan University,Changsha 410082.china 3 College of Science,Harbin engineering University,Harbin 150001,china 4 College of Material Science and Chemical engineering,Harbin engineering University,Harbin 150001,china School of Materials Science and engineering Beijing Institute of Technology Beijing 100081 China Micro-Nano Technologies research center Hunan University Changsha 410082 China College of Science Harbin Engineering University Harbin 150001 China College of Material Science and Chemical engineering Harbin Engineering University Harbin 150001 China

Crystalline SnO2.nanoparticles(NPs) with a diameter less than 6 nm are synthesized using potassium stannate trihydrate as the precursor in a basic *** synthesized NPs can detect ethanol at a ppm level even at 100℃.Furthermore,the NPs have good selectivity to *** excellent ethanol sensing performances are attributed to the small size effect according to the space-charge model.

关键词： SnO2 nanoparticles sensing characteristics

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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2. CHEN ZhengHao3 & ZHANG XiaoZhong4,5 1 Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education, Institute of Low Energy Nuclear Physics, beijing Normal University, beijing 100875, {2. 2.beijing Radiation center, beijing 100875, {2. 3 Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, beijing 100080, {2. 4 Key Laboratory of Advanced Materials of the Ministry of Education, Department of Materials Science and engineering, Tsinghua University, beijing 100084, {2. 5 beijing national center for Electron Microscopy, Tsinghua University, beijing 100084, {2. 1. Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China 2. beijing Radiation center Beijing 100875 China 3. Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China 4. Key Laboratory of Advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing 100084 China 5. beijing national {2. for Electron Microscopy Tsinghua University Beijing 100084 China

The LaMn1-xTexO3+δ (x=0.1, 0.2. 0.3) were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3+ ions are partly converted into Mn2. and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2., Mn3+ and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3+ is much larger or less than the sum of Mn2. and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3+ is close to the sum of Mn2. and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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Deep-Cut Vacuum Distillation in the 10 Mt/a CDU/VDU

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china Petroleum Processing & Petrochemical Technology 2009年第2期11卷 9-13页

作者： Lin Zhuwei1 Mao Fuzhong1 Jiang Bing2.Chen Kaibei3 Chi Ling3 Yan Chun3(1. KBC Advanced Technologies(beijing) Co.,Ltd. beijing 10002. 2. The {2. engineering research center for Rectification Technology,Tianjin University 3. SINOPEC engineering Incorporation) KBC Advanced Technologies (beijing) Co. Ltd. Beijing 100029 China national engineering {2. center for Rectification Technology Tianjin University China SINOPEC engineering Incorporation China

This article introduces the concepts relating to deep-cut vacuum distillation and its suitability,and analyzes the deep-cut vacuum distillation technique licensed by the KBC Advanced Technologies to the 10 Mt/a CDU/VDU of the Qingdao refinery and makes comparison on the test run data after commissioning of the distillation unit. The test results have confirmed that the operation of the CDU/VDU had reached the expected goal to achieve good social and economic benefits.

关键词： CDU/VDU deep cut under vacuum distillation rate

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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 {2. center of Advanced Rolling, University of Science and Technology beijing, beijing 100083, china national engineering {2. center of Advanced Rolling. University of Science and Technology 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

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