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Effects of Ho on the microstructure and mechanical properties of Mg-Zn-Ho-Zr magnesium alloys

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Rare Metals 2011年第2期30卷 131-136页

作者： LI Daquan WANG Qudong DING Wenjiang national engineering Research center for Nonferrous Metals Compositions General Research Institute for Nonferrous Metals Beijing 100088 China national engineering Research center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

The microstructure and mechanical properties of Mg-Zn-Ho-Zr alloys have been investigated in detail. The grain size of the as-cast Mg-Zn-Ho-Zr alloy was greatly decreased by the addition of Ho, and the grain growth during solution treatment was suppressed by Mg-Zn-Ho phases formed at grain boundaries. These thermally stable Mg-Zn-Ho phases could not completely dissolve into the matrix dur- ing solution treatment, and the strengthening effect of solution-plus-ageing treatment weakened. The addition of Ho can greatly enhance the high-temperature elongation of the Mg-Zn-Ho-Zr alloy, but the increase of high-temperature tensile strength was just a little.

关键词： magnesium alloys holmium rare earth additions heat treatment microstmcture mechanical properties

Study on rare earth/alkaline earth oxide-doped CeO_2 solid electrolyte

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Rare Metals 2007年第4期26卷 311-316页

作者： YAN Kai ZHEN Qiang Song Xiwen School of Materials Science and engineering Shanghai University Shanghai 200072 China Research center of Nanoscience and Nanotechnology Shanghai Univeesity Shanghai 200444 China School of Materials Science and engineering Inner Mongolia University of Science and Technology B aotou 014010 China

Five types of rare earth/alkaline earth oxide-doped CeO2 superfine-powders were synthesized by a low-temperature combustion technique. The relevant solid electrolyte materials were also sintered by pressureless sintering at different temperatures. The results of X-ray diffraction and transmission electron microscopy showed that the grain size of the powders was approximately 20-30 nm, and rare earth/alkaline earth oxides were completely dissolved into ceria-based solid solution with fluorite structure. The electrical conductivities of the SmzO3-CeO2 system were measured by the ac impedance technique in air at temperatures ranging from 513-900℃. The results indicated that the ionic conductivities of Srno.2oCe0.8Ol.875 solid electrolyte increase with increasing sintering temperature, and the relationship between the conductivities and measuring temperature obeys the An＇henius equation. Then the SmzO3-CeO2 material was further doped with other rare earth/alkaline earth oxide, and the conductivities improve with the effective index.

关键词： doped ceria rare earth/alkaline earth oxide solid electrolyte conductivity effective index

A MULTI-SCALE APPROACH FOR THE ANALYSIS OF PROPER SAMPLED DATA SCALE IN HOT-WIRE EXPERIMENT OF SQUARE DUCT FLOW

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Journal of Hydrodynamics 2010年第3期22卷 438-444页

作者： ZHANG Bin WANG Tong GU Chuan-gang IDAI Zheng-yuan Key Laboratory for Power Machinery and engineering Ministry of Education Shanghai Jiao Tong University Shanghai 200240 China Key Laboratory for Power Machinery and engineering Ministry of Education Shanghai Jiao Tong UniversityShanghai 200240 China Trane＇s Asia-Pacific Research center Shanghai 200001 China

Without rational criteria to determine the Proper Sampled Data Scale （PSDS）, it would result in the expense of the too much unnecessary processing time and storage space in turbulent experiments. A novel approach for PSDS was established herein on the basis of turbulence theory and statistics. The specific procedure was given by using wavelet tools. A case study to prove the reliability and rationality of this approach was reported, where the sampled hot-wire data were from the experiment of square duct flow and turbulence kinetic energy was selected as the concerned turbulence parameter. It is shown that 2^20 quantities of the sampled data are enough to analyze turbulence kinetic energy in the present experiment. The PSDSs of three turbulence parameters at different Reynolds numbers （Re = 4.60×10^4, 7.68×10^4 and 1.23×10^5） were studied. The results illustrate that the PSDSs increase with the increment of the Reynolds number and the order of concerned turbulence parameter.

关键词： PSDS turbulence statistics wavelet hot-wire square duct flow

Preparation of PFSA/PSf hollow fiber composite membranes with recovered PFSA for the pervaporation separation of EtOH/H_2O

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Science china Chemistry 2010年第1期53卷 273-280页

作者： LANG WanZhong1,2,TONG Wei2,XU ZhenLiang2 & GUO YaJun1 1Department of Chemistry,shanghai Normal University,shanghai 200234,china 2Chemical engineering Research center,East china University of Science and Technology,shanghai 200237,china 1. Department of Chemistry Shanghai Normal University Shanghai 200234 China2. Chemical Engineering Research Center East China University of Science and Technology Shanghai 200237 China

Perfluorosulfonic acid/Polysulfone(PFSA/PSf) hollow fiber composite membranes have been prepared by dip-coating method using PSf ultrafiltration(UF) membrane as substrate with recovered *** composite membranes were applied to the pervaporation separation of 95% ethanol(EtOH)/H2O *** images show that the thickness of the PFSA skin layer of the composite membranes is about 2 μm,much thinner than those of other PFSA composite membranes revealed in the *** of annealing temperature,coating solution concentration and counter-ions of PFSA on the pervaporation performances of the composite membranes were *** total flux decreases and separation factor increases with the increase of annealing *** highest permeation flux of 3230 g m-2 h-1 and a separation factor of 5.4 is obtained for the composite membrane annealed at 80°*** lowest permeation flux of 396 g m-2 h-1 and a separation factor of 27.7 is obtained for the composite membrane annealed at 160°*** permeation performances of the PFSA/PSf composite membrane are evidently influenced by the counter-ions of *** flux sequence of the PFSA/PSf composite membranes with different counter-ions is H+>Li+>Ca2+>Mg2+>Na+>K+>Ba2+>Fe3+>Al3+,and the separation factor sequence is H+Na+>K+.There are very little variations of △Eapp values between the composite membranes with three divalent counterions(Mg2+,Ca2+ and Ba2+),and the △Eapp values of the composite membranes with two trivalent counterions(Fe3+ and Al3+) are relatively high.

关键词： pervaporation hollow fiber composite membrane perfluorslulfonic acid(PFSA) ethanol(EtOH)/H2O mixture

Identification and classification of all potential hemolysin encoding genes and their products from Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai

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Acta Pharmacologica Sinica 2005年第4期26卷 453-461页

作者： Yi-xuan ZHANG~(2,3,4,5) Yan GENG(2,3,4,5) Bo BI~(2,4) Jian-yong HE~4 Chun-fu WU~4 Xiao-kui GUO~3 Guo-ping ZHAO~(2,4,6,7) 2 Research center of Biotechnology,shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,shanghai 200233,china 3 Department of Microbiology and Parasitology,shanghai Second Medical University,shanghai 200025,china 4 The School of Pharmaceutical engineering,Shenyang Pharmaceutical University,Shenyang 110016,china 6 Chinese national Human Genome center at shanghai,ZhangJiang High Tech Park,shanghai 201203,china ResearchcenterofBiotechnology ShanghaiInstitutesforBiologicalSciencesChineseAcademyofSciencesShanghai200233

Aim:To identify and classify all potential hemolysin candidates of Leptospirainterrogans serogroup Icterohaemorrhagiae serovar ***:All of thepotential hemolysin encoding genes were characterized in *** geneswere cloned and expressed in Escherichia *** hemolytic activities of theexpressed proteins were assayed observing the hemolysis on sheep blood *** activities of the hemolysin candidates were measuredby thin-layer chromatography(TLC)and HPLC for *** and secretion of the hemolysins in L interrogans were studied byreverse transcription polymerase chain reaction,Western blot,and enzyme-linkedimmunosorbent *** and Conclusion:The hemolytic activities ofhemolysin candidates(LA0327,LA0378,LA1027,LA1029,LAI650,LA3050,LA3937,LA4004)from L interrogans strain Lai were *** were furtherdivided into two groups,sphingomyelinase hemolysins and non-sphingomyelinasehemolysins,based on their ability to hydrolyze *** of thesehemolysins were actually expressed in living L interrogans and some of themwere secreted into the *** study establishes an essential findcomplete basis for further studying the contribution of hemolysins to the patho-genesis of L interrogans.

关键词： hemolysin Leptospira interrogans sphingo myelinase

Strain Softening and Hardening Behavior in AZ61 Magnesium Alloy

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Journal of Materials Science & Technology 2004年第6期20卷 691-693页

作者： Haitao ZHOU, Liufa LIU, Qudong WANG, Da LU, Xiaoqin ZENG and Wenjiang DINGnational engineering Research center of Light Alloys Net Forming, School of Materials Science and engineering, shanghai Jiao Tong University, shanghai 200030, china Ctr. of Light Alloys Net Forming Sch. of Mat. Sci. and Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

The deformation behavior of AZ61 Mg alloy during hot deformation has been investigated in wide temperature and strain rate range by a Gleeble simulator. Specimens are deformed in compression in the temperature range of 523-673 K and at strain rates of 0.001-1 s-1. It is found that the flow curves exhibit a peak and then decrease towards steady-state of classical DRX, which decrease with rising temperature and decreasing strain rate. The deformation behavior of the specimens can be attributed to the occurrence of strain hardening and softening. As stress decreases, the strain hardening rate declines at a fast rate when temperature rises or strain rate decreases. The shapes of θ-σ curves indicate some important features such as subgrain formation, the criticai stress, the peak stress and steady stress. The onset of DRX can be determined by the point of inflection on θ-σ or Inθ-σ curves.

关键词： AZ61 Mg alloy Recrystallization Strain hardening and softening

Design and Preparation of Bone Tissue engineering Scaffolds with Porous Controllable Structure

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Journal of Wuhan University of Technology(Materials Science) 2009年第2期24卷 174-180页

作者：林柳兰 College of Mechatronics engineering and Automation Shanghai University

A novel method of designing and preparing bone tissue engineering scaffolds with controllable porous structure of both macro channels and micro pores was proposed. The CAD software UG NX3.0 was used to design the macro channels＇ shape, size and distribution. By integrating rapid prototyping and traditional porogen technique, the macro channels and micro pores were formed respectively. The size, shape and quantity of micro pores were controlled by porogen particulates. The sintered β-TCP porous scaffolds possessed connective macro channels of approximately 500 μm and micro pores of 200-400 μm. The porosity and connectivity of micro pores became higher with the increase of porogen ratio, while the mechanical properties weakened. The average porosity and compressive strength offl-TCP scaffolds prepared with porogen ratio of 60wt% were 78.12% and 0.2983 MPa, respectively. The cells＇ adhesion ratio of scaffolds was 67.43%. The ALP activity, OCN content and cells micro morphology indicated that cells grew and proliferated well on the scaffolds.

关键词： bone tissue engineering scaffolds rapid prototyping porous structure

A LOOP DRAWBEAD RESTRAINING FORCE MODEL IN SHEET METAL DEEP DRAWING PROCESS

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 380-386页

作者： Y.J. Luo, S.P. Li, J.F. Zheng, D.N. He, Y.Q. Zhang, J.L. Cheng and J. Y. Jiang 1)national Mold & Die CAD engineering Research center, shanghai 200030, china 2)shanghai Volkswagen Automotive Company Ltd.(SVM), shanghai 201805, china shanghai Jiaotong Univ. Shanghai 200030 China

In sheet metal forming, drawbeads are often used to control uneven material flow which may cause defects such as wrinkles, fracture, surface distortion and springback. Appropriate setting and adjusting the drawbead force is one of the most important pa- rameters in sheet metal forming process control. This paper derives the model of loop drawbead restraining force (DBRF) using plastic forming theory, and gives the min imum blankholding force. Experiments are carried out to verify the proposed DBRF model. The good agreement between the calculated values and experiments data justi- fies the proposed loop drawbead restraining force model.

关键词： drawbead restraining force sheet metal deep drawing

Optimization of HMM Parameters Based on Chaos and Genetic Algorithm for Hand Gesture Recognition

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Journal of Systems engineering and Electronics 2002年第4期13卷 79-84页

作者： Liu Jianghua , Cheng Junshi & Chen Jiapin Information Storage and Research center, shanghai Jiaotong University, shanghai 200030, P. R. china Information Storage and Research center Shanghai jiaotong University Shanghai 200030 P. R. China

In order to prevent standard genetic algorithm (SGA) from being premature, chaos is introduced into GA, thus forming chaotic anneal genetic algorithm (CAGA). Chaos ergodicity is used to initialize the population, and chaotic anneal mutation operator is used as the substitute for the mutation operator in SGA. CAGA is a unified framework of the existing chaotic mutation methods. To validate the proposed algorithm, three algorithms, i. e. Baum-Welch, SGA and CAGA, are compared on training hidden Markov model (HMM) to recognize the hand gestures. Experiments on twenty-six alphabetical gestures show the CAGA validity.

关键词： Chaos theory Experiments Genetic algorithms Optimization