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Geometric Nonlinear Formulation for a Rectangular Plate with Large Deformation

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Journal of Shanghai Jiaotong university(Science) 2007年第6期12卷 831-837,844页

作者：刘锦阳马易志洪嘉振 dept. of eng. Mechanics Shanghai Jiaotong Univ.

Absolute nodal coordinate formulation for a rectangular plate with large deformation was improved. Based on nonlinear elastic theory, a precise strain expression is used to derive the equations of motion. Both shear strain and transverse normal strain are taken into account. Different from the previous absolute nodal coordinate formulation, the absolute nodal coordinates, which describe the displacement and slope of the element nodes, are separated into three parts: the absolute nodal coordinates in X, Y and Z directions, respectively, so that the dimension of the mass, stiffness and force matrices is reduced. Furthermore, by using constant matrices, which can be calculated and saved before simulation, the nonlinear stiffness matrices can be calculated by matrix multiplication for each time step, so that the computational efficiency can be improved. Finally, simulation example of a rectangular plate with large deformation was used to verify the accuracy and efficiency of the present formulation.

关键词： rectangular plate absolute nodal coordinate formulation large deformation

Influence of Error-prone Channel on the Performance of IEEE 802.11 WLAN Utilizing RTS/CTS Handshaking

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Journal of Shanghai Jiaotong university(Science) 2007年第6期12卷 799-804页

作者： Haider M. AlSabbagh 陈建平徐友云 dept. of electron.c eng. Shanghai Jiaotong Univ.

A comprehensive study was presented for WLAN 802.11b using error-prone channel. It was theoretically and numerically evaluated the performance of three different network sizes with the bit rates that available in 802.11b protocol. Results show that throughput does not change with the size of the network for wide range of bit error rates (BERs) and the channel bit rates play a significant role in the main characteristics of the network. A comprehensive explanation has given for the phenomenon of the packet delay suppression at relatively high level of BERs in view of the size of the networks and the BERs. The effect leng.h of the transmitting packets is also investigated.

关键词： IEEE802.11b request to send/clear to send(RTS/CTS) wireless local area network(WLAN) error-prone channel

Model Test of Sand Restraining Force on Pipeline

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China Ocean eng.neering 1996年第1期11卷 107-120页

作者： Zhang Jianguo Yan Chi Yan Shuwang Lecturer, dept. of Hydraulic eng., Tianjin University, Tianjin 300072 Associate Professor, dept. of Hydraulic eng., Tianjin University, Tianjin 300072 Professor, dept. of Hydraulic eng., Tianjin University, Tianjin 300072 dept. of Hydraulic eng. Tianjin University Tianjin 300072

This paper describes the model tests for determining the axial friction and the lateral resistance of sand to pipeline by using fine sand and prototype pipeline, and the calculation method based on limit analysis theo... 详细信息

关键词： model test axial friction lateral resistance penetration

Partition Behavior of Penicillin in Three-liquid-phase Extraction System

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过程工程学报 2006年第3期6卷 363-368页

作者：谭显东季清荣常志东 dept. Environ. eng. Chengdu Univ. Information Technol.ChengduSichuan 610225China State Key Lab. Biochem. eng. Lab. Sep. Sci. & Eng.Inst. Process Eng.CASBeijing 100080China

Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system,which is composed of butyl acetate (BA),polyethylene glycol (PEG),ammonia sulfate (NH4)2SO4 and water (H2O). The main components in the top,middle and bottom phases are butyl acetate,polyethylene glycol aqueous solution and ammonia sulfate aqueous solution,respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature,respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system,including initial concentrations of phase-forming components PEG and (NH4)2SO4,PEG molecular weight,pH,initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH,while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b,Dm/b and the decrease of Dt/m,while their mass fractions in all phases were almost independent on their initial concentrations.

关键词： three-phase extraction penicillin partition

Stochastic Optimization of Dual Constraints with Anticipation

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Journal of China Textile University(eng.ish Edition) 2000年第3期17卷 123-126页

作者：费为银雷耀斌吴让泉邵世煌 dept. of Appl. Math. Anhui Inst. of Mech. and Elec. Eng. Wuhu 241000 China Coll. of info. and Technol. China Textile Univ. Shanghai 200051 China dept. of Appl. Math. China Textile Univ. Shanghai 200051 China Coll. of info. and Technol. China Textile Univ. Shanghai 200051 China

A stochastic control model is *** objective of the investor is to maximize expected utility from ***,the investor possesses info.ma-tion about the terminal values of the components of the Brownian motion which drives ... 详细信息

关键词： stochastic financial control enlargement of filtrations utility optimal decision anticipation .

Removal of Anionic Metal Ions from Wastewater by Hydroxide-type Adsorbents

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过程工程学报 2006年第3期6卷 357-362页

作者： Toyohisa Fujita Gjergj Dodbiba Jun Sadaki Atsushi Shibayama dept. Geosystem eng. Graduate School Eng.The University of TokyoTokyo 113-8654Japan dept. Material-Process. eng.&Appl. Chem. for Environ. Faculty Eng.&Resources Sci.Akita Univ.Akita 010-8502Japan

Generally speaking,anionic metal concentrations in wastewater from industries and mineral processing plants are well above the allowed limits for effluent set by the Ministry of Environment of Japan. Nowadays,the removal of anionic ions has been considered difficult and development of new process is desperately needed. In this paper,we report the development of three hydroxide-type adsorbents,illustrating their adsorption efficiency in removing As,Se,Mo and Sb ions from aqueous solutions. The main finding of this work was that the adsorption behavior was influenced very much by both the pH and the adsorbent concentration. Nevertheless,the newly developed hydroxide-type adsorbents were very effective in reducing the concentration of those anionic ions.

关键词： hydroxide-type adsorbent adsorption anionic metal ions removal wastewater

NUMERICAL SIMULATION OF SEPARATED FLOW NEAR GROYNE

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Journal of Hydrodynamics 2002年第4期14卷 47-52页

作者： Jiang, Chang-Bo Chen, Yong-Kuan Bai, Yu-Chuan Zhao, Zi-Dan dept. of River and Coast eng. Changsha Commun. Univ. Changsha 410076 China dept. of Hydraulic eng. Tsinghua Univ. Beijing 100084 China Inst. of sediment on River eng. Tianjian Univ. Tianjian 300072 China

A numerical model was developed to simulate the flow around non-submeged groyne in two dimensions, which was based on N-S equations with Smagorinsky's subgrid-scale turbulence model. Flow phenomenon and results measured practically agree with the calculation results very well, and this model could be used to simulate the characteristics of the eddies of upper and down reaches around spur-dikes successfully.

关键词： Computational fluid dynamics Computer simulation Erosion Mathematical models Navier Stokes equations Turbulent flow

A ROBUST ADAPTIVE VIDEO ENCODER BASED ON HUMAN VISUAL MODEL

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Journal of electron.cs(China) 2003年第2期20卷 142-149页

作者： Yin Hao Zhang Jiangshan Zhu Yaoting Zhu Guangxi (dept. of electron.cs & info. eng., Huazhong University of Sci. & Tech., Wuhan 430074) dept. of electron.cs & info. eng. Huazhong University of Sci. & Tech. Wuhan

A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed. The encoder combines the best features of Fine Granularity Scalable (FGS) coding, framedropping coding, video redundancy coding, and human visual model. According to packet loss and available bandwidth of the network, the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model, rate shaping, and periodically inserting key frame. The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional FGS algorithm. It is shown that RAVE is a very efficient robust video encoder that provides improved visual quality for the receiver and consumes equal or less network resource. Results are confirmed by subjective tests and simulation tests.

关键词： FGS coding Redundancy coding Human visual model Rate shaping MPEG 4

Study of Microstructure and Magnetic Properties of Pr-Fe-B-Cu Permanent Magnets by Hot Deformation

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Journal of Rare Earths 2002年第3期20卷 188-192页

作者：陈秀云姜忠良高天明吴严杨昌平朱静 dept. of Mater. Sci. and eng. Sch. of Mater. Sci. and Eng. Tsinghua Univ. Beijing 100084 China

The relationship between the microstructures and magnetic properties of rare earth cast permanent Pr Fe B Cu alloys by hot deformation was studied. Fine and well aligned column grains can be obtained by using a proper solidification mould with a high cooling rate. The soft magnetic phase α Fe can be removed during proper annealing treatment. Hot pressing can produce the anisotropy and refine the grain size, so that the magnetic properties are greatly improved. The technique has the advantages of simple processing, low cost and high benefit, compared with the common sintering processing. Under the condition of the deformation temperature of 1073 K, 90% strain and strain rate of 40×10 -3 s -1 , the magnetic properties obtained are: B r=1.05 T, i H c=955 kA·m -1 , ( BH ) max =207 kJ·m -3 .

关键词： rare earths hot deformation anisotropy sintering