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Multifield coupling model and its applications for pile foundation in permafrost

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Science china Earth Sciences 2005年第7期48卷 968-977页

作者： WU Yaping1,2. ZHU Yuanlin2. GUO Chunxiang1, SU Qiang1 & MA Wei2.1. School of Civil engineering, Lanzhou Jiaotong University, Lanzhou 730070, china 2. State Key Laboratory of Frozen Soil engineering, Cold and Arid Regions Environmental and engineering Research institute, Chinese Academy of Sciences, Lanzhou 730000, china School of Civil engineering Lanzhou Jiaotong University Lanzhou 730070 China State Key Laboratory of Frozen Soil engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Importing the interface element which links the frozen soil base with concrete piles and considering the couplings of stress field, temperature field and moisture field, this paper es- tablishes the nonlinear visco-elastic plastic finite element model of pile-soil. For a practical bridge structure the stress field and displacement field of single pile in freezing process are calculated. This paper emphatically studies the process of the tangential frost heave stress field, freezing stress field and displacement field varying with time, and ulteriorly studies time variation process of single pile carrying capacity in freezing process.

关键词： permafrost pile foundation freezing process multifield coupling analysis model.

Effect of Excipients on Stability and Structure of rhCuZn-SOD Encapsulated in PLGA Microspheres

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Chemical Research in Chinese Universities 2004年第3期20卷 323-327页

作者： LIU Ling 1,2.,GE Yu 1 and YUAN Qin-sheng 1 1. State Key Laboratory of Bioreactor engineering and institute of Biochemistry,East{2. University of Science and Technology,Shanghai 2.02.7,P. R.{2. 2. Public Health School,Nanjing Medical University,Nanjing 2.002.,P. R.{2. E china Univ Sci & Technol State Key Lab Bioreactor Engn Shanghai 200237 Peoples R China E china Univ Sci & Technol Inst Biochem Shanghai 200237 Peoples R China Nanjing Med Univ Sch Publ Hlth Nanjing 210029 Peoples R China

When a protein is encapsulated into poly( DL -lactide-co-glycolide)(PLGA) microspheres by means of the double-emulsion method,the harsh microspheres formation process including ultrasonification,exposure to an organic solvent and a polymer may cause the denaturation of the protein. In this study,we investigated the enzymatic activity change and the effect of the excipients on the stability of recombinant human Cu,Zn-superoxide dismutase(rhCu,Zn-SOD) during the emulsification. The specific activity recovery was found to be concentration dependent and the excipients involved such as PEG 600 and Tween 2.,and trehalose were shown to increase the stability of rhCu,Zn-SOD. The protein structural integrity within the microspheres was analyzed by FTIR. The structure of rhCu,Zn-SOD within PLGA microspheres containing trehalose was found to be similar to that of the native solid state,whereas the protein encapsulated during the preparation in the absence of any excipient changed due to the possible hydrophobic interaction with the polymer. The results suggest that a rational stability strategy for protein to be encapsulated into microspheres should aim at different processes.

关键词： Poly( DL -lactide-co-glycolide)(PLGA) microsphere Recombinant human Cu Zn-superoxide dismutase(rhCu Zn-SOD) Fourier transform infrared(FTIR) spectroscopy Protein stability Excipient

Solving the input data in error correc-tion of optical fabrication by finite Fourier coefficient algorithm

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Science china(Technological Sciences) 2006年第1期49卷 50-60页

作者： CHENG Haobo1,2. SUN Guozheng3 & FENG Zhijing2.1. Department of Optical engineering, Beijing institute of Technology, Beijing 100081,{2. 2. Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084,{2. 3.{2. North Industries Group Corporation, Beijing 100089,{2. 1. Department of Optical engineering Beijing Institute of Technology Beijing 100081 China 2. Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China 3. china North Industries Group Corporation Beijing 100089 China

A free-form lens (FFL) is a special surface that is difficult to be fabricated. FFL are usually fabricated by computer-controlled optical surfacing (CCOS) technique. During CCOS, the material removal amount is determined by the unit removal function (URF) convoluting with the input data――the dwell time. When the removal amount and the URF are known, how to solve the input data involves the special algorithm――deconvolution. Usually, the input data are solved by virtue of low pass filter or iterative methods. However, an approximation solution would destroy the machining stability nec-essary to perform precisely CCOS. In this paper, to solve the input data, a new method that is based on the finite Fourier coefficient is put forward. It can give a continuous and accurate solution for fabricating choice. Several parameters are simulated, which influ-ence the process of CCOS, and evaluating on the effect of the method is also carried out. Experimental results verify that this method is suitable for guiding the manufacturing of high precision FFL.

关键词： optical fabrication, computer controlled optical surfacing, free-form lens, finite Fourier coefficient, error correction.

A low frequency piezoelectric power harvester using a spiral-shaped bimorph

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1,2.HU Hongping2.& YANG Jiashi3 1. institute of Mechanics and Sensing Technology,Central South University,Changsha 410083,china 2. Department of Mechanics,Huazhong University of Science and Technology,{2. 43.074,china 3. Department of engineering Mechanics,University of Nebraska,Lincoln,NE 68588-052.,USA 1. institute of Mechanics and Sensing Technology Central South University Changsha 410083 China 2. Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. Department of engineering Mechanics University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.

Characteristics of shape memory and superelasticity for TiNi thin films

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中国有色金属学会会刊：英文版 2000年第3期10卷 375-377页

作者： HE Zhi rong(贺志荣) 1, S.Miyazaki 2.1. Department of Mechanical engineering, Shaanxi institute of Technology, Hanzhong 72.003, P.R.{2. 2. University of Tsukuba, Japan Shaanxi Inst Technol Dept Mech Engn Hanzhong 723003 Peoples R China Univ Tsukuba Tsukuba Ibaraki 305 Japan

TiNi shape memory alloy thin films were deposited by using a RF magnetron sputtering apparatus. The transformation and shape memory characteristics of the thin films have been investigated by using DSC and tensile tes... 详细信息

关键词： TiNi alloy shape memory effect superelasticity thin film

Theoretical calculation of the impact work in the alloying non-quenched and tempered steel

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Science china(Technological Sciences) 2006年第3期49卷 257-273页

作者： LIU Zhilin1, LIN Cheng1 & GUO Yanchang2.1. Department of Materials and Chemical engineering, Liaoning institute of Technology, Jinzhou 12.001,{2. 2. The Technical Center of Benxi Iron and Steel Group Corporation, Benxi 117000,{2. Department of Materials Chemical engineering Liaoning Institute of Technology Jinzhou 121001 China The Technical Center of Benxi Iron Steel Group Corporation Benxi 117000 China

Coupled with hot-continuous rolling technology and based on the calculation of the finishing rolling impact work in the non-quenched and tempered Si-Mn steel, the calculations of the finishing rolling impact work in the alloying non-quenched and tempered steel with the elements of Cr, Ni, Mo, W, Cu, V, Nb and Ti are studied with the covalent electron number nA of the strongest bond in alloying phases, the smallest electron density difference ?ρ of phase interfaces, and the number of atom states σ (σ′) which keep the interface electron density continuous. The calculated results show that the finishing rolling impact work of the alloying non-quenched and tempered steel intensely depends on strengthening mechanisms. The solution strengthening, interface strengthening, precipita- tion strengthening of pearlite, and dispersion strengthening will result in the decrease of the finishing rolling impact work; the refinement strengthening, the precipitation strength- ening of V, Nb and Ti in α-Fe-C-V(Nb, Ti), and the residual austenite containing Ni on the boundary of α-Fe-C-Ni will increase the impact work; and the increments or decrements can be calculated with nA, ?ρ, σ (σ′) and weights of alloying elements. The calculation formulas of the finishing rolling impact work in this paper are intergraded with the sug- gested ones of the finishing rolling tensile strength, yield strength, and elongation of the non-quenched and tempered steel. The calculated results agree well with the measured ones.

关键词： alloying non-quenched and tempered steel, electron structure, impact work, calculation.

Preparation of Immobilized ε-Polylysine PET Nonwoven Fabrics and Antibacterial Activity Evaluation

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Journal of wuhan University of Technology(Materials Science) 2011年第4期26卷 675-680页

作者：郝丽梅杨荆泉 institute of Medical Equipment the Academy of Military Medical Sciences National Bioprotection engineering Center

A novel antibacterial material （L-PET） was prepared by immobilizing ε-polylysine on polyethylene terephthalate （PET） nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy （SEM） was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy （XPS） were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.

关键词： PET nonwoven fabric ε-polylysine immobilization antibacterial activity antibacterial material

Security Research on engineering Database System

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厦门大学学报（自然科学版） 2002年第S1期41卷 288-289页

作者： REN Jian-ping 1,2. SONG Han-tao 2. LIANG Yun-rong 2.(1. North china institute of Technology, Taiyuan 030051, china 2. Beijing institute of Technology, Beijing 100081, china)

Engine engineering database system is an oriented C AD applied database management system that has the capability managing distributed data. The paper discusses the security issue of the engine engineering database management system (EDBMS). Through studying and analyzing the database security, to draw a series of securi ty rules, which reach B1, level security standard. Which includes discretionary access control (DAC), mandatory access control (MAC) and audit. The EDBMS implem ents functions of DAC, MAC and multigranularity audit. DAC solves the problems o f role inheritance, right contain, authorization identify and cascade revoke, et c; MAC includes subject and object security setup rule, security modify rule and multilevel relation access operation rule, etc; Audit allows making the sub ject, object or operation type as different audit object to implement flexible a nd multigranularity audit method. The model is designed act as a security agent to access daemon database. At present, the model is implemented which runs on th e Windows 2.00 environments.

关键词： engineering database management system (EDBMS) s ecurity agent security level

Optimality strategy of a sealed-offer simultaneous bargaining protocol

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Science china(Information Sciences) 2011年第1期54卷 79-90页

作者： ZHANG LinLan1,2.CHEN XueGuang2.& HONG Liu2.1School of Business,Hubei University,wuhan 430062.china 2.2. of Systems engineering,Huazhong University of Science and Technology,wuhan 43.074,china 1. School of Business Hubei University Wuhan 430062 China2. Institute of Systems Engineering Huazhong University of Science and Technology Wuhan 430074 China

Alternating-offer bargaining protocol is the most predominant way for solving bilateral bargaining ***,alternating-offer may consume much time and cause a low effciency in some ***, a deadlock in which both negotiators are unwilling to concede or refuse to disclose more information may arise. Then mediation is *** paper presents an agent-based sealed-offer simultaneous bargaining protocol by introducing a nonbiased *** information of both agents is considered completely *** our agent-based model,both agents simultaneously submit their respective offers to the mediate *** offers of each agent are not revealed to the *** design can discourage counter-speculation and effectively control fraud and misrepresentation in a certain ***,we analyze how an agent can exploit the available information in selecting a strategy that maximizes its expected utility and give the optimal offers of each agent at each stage of the *** groups of automated experiments are conducted to evaluate the performance of the proposed automated negotiation procedure.

关键词： automated negotiation bargaining sealed-bid optimal strategy