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Effect of cold-rolling on tensile strength of SiCw/Al composite

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Rare Metals 2003年第4期22卷 285-288页

作者： ZHANGWenlong ZHANGMu GUMingyuan WANGDezun YAOZhongkai StateKeyLabofMMCs ShanghaiJiaotongUniversityShanghai200030China SchoolofMaterialsscienceandEngineering HarbinInstituteofTechnologyHarbin150001China

SiC_w/Al composite was fabricated through a squeeze cast route and coldrolled to about 30 percent, 50 percent and 70 percent reduction In thickness, respectively. Thelength of whiskers in the composite before and after rolling was examined using SEM. Some of therolled composites were recrystallization annealed to remove the work hardening of matrix alloy. Thetensile strength of the rolled and annealed SiC_w/Al composites was examined and then associatedwith the change of the whisker length and the work hardening of matrix alloy. It was found that thetensile strength is a function of the degree of cold rolling. For the cold rolled composites, withthe increase in the degree of cold rolling, the tensile strength increases at first, and decreaseswhen the degree of cold rolling exceeds 50 percent. For the annealed ones, however; the tensilestrength decreases monotonously with the increase in rolling degree. The different changes intensile strength between the rolled and annealed composites could be attributed to the result of thecompetition between the work hardening of matrix resulting from the cold rolling and the worksoftening arising from the change of whisker length.

关键词： metal matrix composites tensile strength cold rolling microstructure

Modeling Research on Manufacturing Execution System Based on Large-scale System Cybernetics

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Journal of shanghai jiaotong university(science) 2008年第6期13卷 744-747页

作者：吴瑜许晓栋李从心 Department of Plasticity technology Shanghai Jiaotong UniversityShanghai 200030China

A cybernetics model of manufacturing execution system(MES CM) was proposed and studied from the viewpoint of *** with the features of manufacturing system, the MES CM was modeled by"generalized modeling"method that is discussed in large-scale system *** mathematical model of MES CM was constructed by the generalized operator model, and the main characteristics of MES CM were analyzed.

关键词： cybernetics manufacturing execution system large scale system

RESEARCH ON THE CHAOS DYNAMIC MODEL OF RUNOFF

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Journal of Hydrodynamics 2000年第2期12卷 85-91页

作者： Jiang, Chuanwen Quan, Xianzhang Zhang, Yongchuan Hou, Zhijian Huazhong Univ of science and Technology Wuhan China

The identification of chaos in the study of runoff serial was introduced and a dynamic model of runoff with the observed values of runoff serial was proposed. By checking the difference between the original serial and substitute serial, the nature of the runoff serial can be identified. This paper thus provides an effective method for studying the rule of runoff. The study of the chaos features of runoff and the understanding of its nonlinear dynamic model are of great significance to the understanding of the rules of runoff movement and the accurate prediction.

关键词： Chaos theory Dynamics Models Runoff

Preparation of grain size controlled boron-doped diamond thin films and their applications in selective detection of glucose in basic solutions

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science china Chemistry 2010年第6期53卷 1378-1384页

作者： ZHAO JianWen1,2,WANG JinLiang3,ZHI JinFang3 & ZHANG ZhiMing4 1college of Chemistry and Chemical Engineering,Jishou university,Jishou 416000,china 2Schools of Materials science and Engineering,Nanyang Technological university,639798,Singapore 3Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering,Technical Institute of Physics and Chemistry & Graduate university of Chinese Academy of sciences,Beijing 100080,china 4Research Institute of Micro-Nano science and technology,shanghai Jiao Tong university,shanghai 200030,china 1. college of Chemistry and Chemical Engineering Jishou University Jishou 416000 China2. Schools of Materials Science and Engineering Nanyang Technological University 639798 Singapore Singapore3. Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering Technical Institute of Physics and Chemistry & Graduate University of Chinese Academy of Sciences Beijing 100080 China4. Research Institute of Micro-Nano Science and Technology Shanghai Jiao Tong University Shanghai 200030 China

Boron-doped diamond (BDD) thin films with different crystal grain sizes were prepared by controlling the reacting gas pressure using hot filament chemical vapor deposition (HFCVD).The morphologies and structures of the prepared diamond thin films were characterized by scanning electron microscopy (SEM) and Raman *** electrochemical responses of K4Fe(CN)6 on different BDD electrodes were *** results suggested that electron transfer was faster at the boron-doped nanocrystalline diamond (BDND) thin film electrodes in comparison with that at other BDD thin film *** prepared BDD thin film electrodes without any modification were used to directly detect glucose in the basic *** results showed that the as-prepared BDD thin film electrodes exhibited good selectivity for detecting glucose in the presence of ascorbic acid (AA) and uric acid (UA).The higher sensitivity was observed on the BDND thin film grown on the boron-doped microcrystalline diamond (BDMD) thin film surface,and the linear response range,sensitivity and the low detection limit were 0.25–10 mM,189.1 μA mmol-1 cm-2 and 25 μM (S/N=3) for glucose in the presence of AA and UA,respectively.

关键词： diamond thin films electrochemical properties selective glucose detection

Continuous Separation of Inclusions from Aluminum Melt Flowing in a Circular Pipe using a High Frequency Magnetic Field

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Journal of Materials science & technology 2003年第3期19卷 221-225页

作者： Da SHU, Baode SUN, Ke LI, Jun WANG Yaohe ZHOUState Key Laboratory of Metal Matrix Composites, shanghai Jiao Tong university, shanghai 200030, china Lab. of Metal Matrix Composites Shanghai Jiaotong Univ. Shanghai 200030 China

The continuous separation of inclusions from aluminum melt flowing in a circular pipe using a high frequency magnetic field was investigated both theoretically and experimentally. The separation efficiency was calculated based on the trajectory method and compared with experimental results. It is found that the separation efficiency is a function ofnondimensional parameters ti . The effective way to improve the separation efficiency is to increase the effective magnetic flux density and decrease the pipe radius, and the value of should be kept about 2 in order to obtain the optimum separation efficiency.

关键词： Aluminum Inclusions Magnetic field Separation efficiency

Effects of cooling rate on the microstructure and electrical properties of Dy_2O_3-doped ZnO-based varistor ceramics

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Rare Metals 2007年第1期26卷 39-44页

作者： LIU Hongyu KONG Hui JIANG Dongmei SHI Wangzhou MA Xueming ZHANG Huining Department of Physics East China Normal University Shanghai 200062 China college of science Wuhan University of Science and Technology Wuhan 430081 China shanghai Research Institute of Petrochemical technology Shanghai 201208 China

The microstructure, electrical properties, and density of Dy2O3-doped ZnO-based varistor ceramics, prepared using high-energy ball milling （HEBM） and sintered at 800℃, were investigated by increasing the cooling rate in the order of H （slow cooling in furnace） → L （cooling in furnace） → K （cooling in air）. With the increase in cooling rate, the grain size and density decreased, the breakdown voltage （VImA/mm） increased, and the nonlinear coefficient （α） and leakage current （IL） exhibited extremum. The sample with the cooling type L showed the best properties with the breakdown voltage of 2650 V/ram, o：of 20.3, IL of 5.2 laA, and density of 5.42 g/cm^3. The barrier height （ФB）, donor concentration （Nd）, density of the interface states （Nd）, and barrier width （ω） all exhibited extremum during the alteration in cooling rate. The different relative amount of Bi-rich phase and its distribution as well as the characteristic parameters of grain boundary, resulting from the alteration of cooling rate, led to the changes in the properties of varistor ceramics.

关键词： varistor ZnO Dy2O3 microstructure electrical properties high-energy ball milling low-temperature sintering

cvhA Gene of Streptomyces hygroscopicus 10-22 Encodes a Negative Regulator for Mycelia Development

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Acta Biochimica et Biophysica Sinica 2006年第4期38卷 271-280页

作者： Heng-An WANG~(1,2#) Lei QIN~(2#) Ping LU~(1*) Zhi-Xuan PANG~2 Zi-Xin DENG~(3*) Guo-Ping ZHAO~(2*) 1 Biotechnology Institute,School of Agriculture and Biology,shanghai jiaotong university,shanghai 201101,china 2 Laboratory of Molecular Microbiology,Institute of Plant Physiology and Ecology,shanghai Institute for Biological sciences,Chinese Academy of sciences,shanghai 200032,china 3 Bio-X life science Research Center,shanghai jiaotong university,shanghai 200030,china. BiotechnologyInstitute SchoolofAgricultureandBiologyShanghaiJiaotongUniversityShanghai201101China LaboratoryofMolecularMicrobiology InstituteofPlantPhysiologyandEcologyShanghaiInstituteforBiologicalSciencesChinese

A five-gene cluster cvhABCDE was identified from Streptomyces hygroscopicus *** thefirst gene of this cluster,cvhA encoded a putative sensor histidine kinase with a predicted sensor domainconsisting of two trans-membrane segments at the N-terminus and a conserved HATPasecdomain at the *** C-terminus polypeptide of CvhA expressed in Escherichia coli was purified and shown to beautophosphorylated with [γ-32P]ATP in *** phosphoryl group was acid-labile and basic-stable,whichsupported histidine as the phosphorylation *** obvious difference of mycelia development was ob-served between the null mutant of cvhA generated by targeted gene replacement and the wild-type parentalstrain 10-22 grown on solid soya flour medium with 2%-8% glucose or sucrose,but the cvhA mutant couldform much more abundant aerial mycelia and spores than the wild-type strain on solid soya flour mediumsupplemented with 6%-8% mannitol,6%-8% sorbitol,4%-6% mannose,or 4%-6% *** pheno-type was complemented by the cloned wild-type cvhA gene,and no difference was observed for growthcurves of the cvhA mutant and the wild strain in liquid minimal medium with the tested sugars at a concen-tration of 4%,6% and 8%.We thus propose that CvhA is likely a sensor histidine kinase and negativelyregulates the morphological differentiation in a sugar-dependent manner in *** 10-22.

关键词： sensor histidine kinase aerial mycelia sugar metabolism

Expert Network for Die Casing Defect Analysis

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Journal of Materials science & technology 2003年第4期19卷 320-323页

作者： Jiadi WANG, Yongfeng JIANG, Chen LU and Wenjiang DINGNational Engineering Research Center for Light Alloy Net Shaping, shanghai Jiao Tong university, shanghai, 200030, china Ctr. for Light Alloy Net Shaping Shanghai Jiaotong Univ. Shanghai 200030 China

Due to the competition and high cost associated with die casting defects, it is urgent to adopt a rapid and effective method for defect analysis. In this research, a novel expert network approach was proposed to avoid some disadvantages of rule-based expert system. The main objective of the system is to assist die casting engineer in identifying defect, determining the probable causes of defect and proposing remedies to eliminate the defect. 14 common die casting defects could be identified quickly by expert system on the basis of their characteristics. BP neural network in combination with expert system was applied to map the complex relationship between causes and defects, and further explained the cause determination process. Cause determination gives due consideration to practical process conditions. Finally, corrective measures were recommended to eliminate the defect and implemented in the sequence of difficulty.

关键词： Neural network Expert system Die casting Defect analysis Back propagation

VIBRATION OF A SINGLE PROTEIN BUBBLE IN BINGHAM LIQUID

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Journal of Hydrodynamics 2009年第5期21卷 658-668页

作者： WANG Hai-min JIANG Xu-ping MA Jian-min ZHANG Wen college of Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Department of Mechanics and Engineering science Fudan University Shanghai 200433 China

The vibration of a single protein bubble may take place under the action of high pressure difference. In this process, the bubble wall may experience a finite deformation. The equation describing the dynamics of the protein bubble with viscoelastic film in Bingham liquid is derived. A numerical solution to this equation is carried out to study the effect of liquid pressure, the characteristic parameters of Bingham liquid and the viscosity of the protein film on the finite deformation of the bubble. The results show that the vibration of the protein bubble wall is caused by the action of pressure difference, the elastic stress in finite deformation and the dissipation of viscosity of the protein film and Bingham liquid. The vibration is nonlinear. Decreasing the pressure difference between gas and Bingham liquid on both sides of the protein bubble will lead to a change of vibration performance. The frequency and amplitude are reduced, tegether with the speed of vibration damping. In addition, the deformation rate of the bubble is smaller when the amplitude of vibration is reduced, which means shorter time to reach a balance state. On the other side, the increase of the magnitude of viscosity of the protein film or the plastic viscosity of Bingham liquid can restrain the vibration of the protein bubble wall in the course of finite deformation, as a result, the load bearing capacity of bubble is enhanced.

关键词： protein bubble Bingham liquid vibration finite deformation viscosity