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Microstructure of Cu_(60)Zr_(2.)Ti_(2.) bulk metallic glass rolled at different strain rates

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Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 394-399页

作者： LI JinFu,CAO QingPing & ZHOU YaoHe State Key Laboratory of Metal Matrix Composites,school of Materials Science and engineering,{2. jiao tong university,{2. 2.0030,China State Key Laboratory of Metal Matrix Composites School of Materials Science engineering Shanghai Jiao Tong University Shanghai 200030 China

The structural evolution of Cu60Zr2.Ti2. bulk metallic glass during rolling at different strain rates and cryogenic temperature was investigated by X-ray diffraction (XRD),differential scanning calorimetry (DSC) and high-resolution transmission electron microscopy (HRTEM). It is revealed that the deformation-induced transformation is strongly dependent on the strain rate. At the lowest experimental strain rate of 1.0×10-4 s-1,no phase transformation occurs until the highest deformation degree reaches 95%. In a strain rate range of 5.0×10-4-5.0×10-2.s-1,phase separation oc-curs in a high deformation degree. As the strain rate reaches 5.0×10-1 s-1,phase separation and nanocrystallization concur. The critical deformation degree for oc-currence of phase transformation decreases with the strain rate increasing.

关键词： metallic glass inhomogeneous deformation strain rate phase separation nanocrystallization

Simultaneously catalytic removal of NOx and particulate matter on diesel particulate filter

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Chinese Science Bulletin 2003年第3期48卷 305-308页

作者： LIU Guanghui, HUANG Zhen, SHANGGUAN Wenfeng & YAN Cunxian school of mechanical and Power{2., shanghai jiao tong Uni-versity, shanghai 2.0030, China school of mechanical and Power{2. Shanghai Jiao Tong University Shanghai 200030 China

The simultaneous removal of NOx and particu-late matter (PM) exhausted from diesel engine was studied with a diesel particulate filter (DPF) on which a mixed metal oxide catalyst, Cu0.95K0.05Fe2.4 was loaded. The NOx reduc-tion was observed in the same temperature range of the CO2.formation, implying the occurrence of the simultaneous re-moval of NOx and PM in an oxidizing atmosphere. It was shown that SOF and soot in PM are attributed to the reduc-tion of NOx at lower and higher temperatures, respectively. The oxidation of PM was enhanced by the coexistence of NO and O2. The ignition and exhaustion temperatures of PM decrease as the order NO>O2.NO+O2. This is a combined process of PM trapping as well as the catalytic reactions of soot oxidation and NOx reduction, promising the most de-sirable after-treatment of diesel exhausts.

关键词：柴油机 NOx 颗粒物同时催化去除排气净化过滤器金属氧化物催化剂

Accountable authority key policy attribute-based encryption

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Science China(Information Sciences) 2012年第7期55卷 1631-1638页

作者： WANG YongTao 1,2.,CHEN KeFei 1,3 ,LONG Yu 1,4 & LIU ZhaoHui 2.1 Department of Computer Science and engineering,shanghai {2. tong {2.,shanghai 2.02.0,China 2.China Information Technology Security Evaluation Center,Beijing 100085,China 3 shanghai Key Laboratory of Scalable Computing and Systems,shanghai {2. tong {2.,shanghai,2.02.0,China 4 State Key Laboratory of Information Security,Graduate school of Chinese Academy of Sciences,100039,China 1. Department of Computer Science and engineering Shanghai Jiao Tong University Shanghai 200240 China2. China Information Technology Security Evaluation Center Beijing 100085 China3. Shanghai Key Laboratory of Scalable Computing and Systems Shanghai Jiao Tong University Shanghai 200240 China4. State Key Laboratory of Information Security Graduate School of Chinese Academy of Sciences Beijing 100039 China

We present an accountable authority key policy attribute-based encryption (A-KPABE) *** this paper,we extend Goyal's work to key policy attribute-based encryption *** first generalize the notion of accountable authority in key policy attribute-based encryption scenario,and then give a *** addition,our scheme is shown to be secure in the standard model under the modified Bilinear Decisional Diffie-Hellman (mBDDH) assumption.

关键词： accountable authority key policy attribute-based encryption standard model access structure

Application of Fourier Slice Theorem in Wigner Operator Theory and New Complete Representation

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Communications in Theoretical Physics 2009年第11期52卷 829-831页

作者： WANG tong-tong~1 and FAN Hong-Yi~(2.3)1 {2. of Mathematics and Physics, Huangshi Institute of Technology, Huangshi 435003, China2.Department of Material Science and engineering, {2. of Science and Technology of China, Hefei 2.002., China3 Department of Physics, shanghai jiao tong university, shanghai 2.0030, China school of Mathematics and Physics Huangshi Institute of Technology Huangshi 435003 China Department of Material Science and engineering University of Science and Technology of China Hefei 230026 China Department of Physics Shanghai Jiao Tong University Shanghai 200030 China

By applying the Fourier slice theorem,S;（λ）=∫;P;（t）e;=F（λcosθ,λsinθ）,where P;（t）is aprojection of f（x,p）=（?）F（u,v）e;dudv along lines of constant,to the Wigner operator we are naturally led toa projection operator（pure state）,which results in a new complete *** Weyl orderimg formalism of theWigner operator is used in the derivation.

关键词： Wigner operator Fourier slice theorem new complete representation

FLOW NOISE MEASUREMENT OF SURFACE SHIP WITH TOWED MODEL

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Journal of Hydrodynamics 2008年第6期20卷 784-789页

作者： GAO Xiao-peng BI Yi MIAO Guo-ping school of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200030 China College of Naval Architecture and Power Naval University of Engineering Wuhan 430033 China

In this article, a new acoustic test technique using towed model was introduced to study flow noise caused by a surface ship. The project of model test was be properly designed for acoustic signal collecting and with the help of appropriate data processing method different kinds of acoustic sources could be successfully identified. A lot of work about fuid noise could be carried on with the towed model, and the noise corresponding to low frequency which is especially interested for its long distance radiating with small attenuation could also be studied in this way.

关键词： acoustic test surface ship towed model flow noise short-time Fourier transform

Research on Influence of Cutting Conditions on Roundness of Ultra-thin Wall Parts in Ultrasonic Vibration Cutting

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厦门大学学报（自然科学版） 2002年第S1期41卷 75-76页

作者： jiao Feng 1, ZHAO Bo 1,2. LIU Chuan-shao 1, GAO Guo -fu 1 (1. Department of mechanical {2., jiaozuo Institute of Techno logy, Henan 454000, China 2. Institute of mechanical {2., shanghai jiaotong university, shanghai 2.0030, China)

In the paper, the experimental researches were carr ie d out to discuss the roundness forming rule and the influence of cutting paramet ers on roundness by ultrasonic vibration cutting of the camera’s guiding drawtu be with 47.75 mm diameter and 0.6～1.5 mm wall thickness. The research results s h ow that the roundness error of ultra-thin wall parts in ultrasonic vibration cu tting is only one third of that in common cutting. The relations between the rou ndness error and the cutting parameters behave as: (1) The roundness error in co mmon cutting decreases gradually with the rise of cutting speed, while in ultras onic cutting, the roundness changes not obviously till the cutting speed is up t o a value, which is nearly equal to one third of the critical velocity. Then the roundness of workpiece will begin to increase slowly. (2. The roundness error i ncreases along with the feed rate both in common cutting and ultrasonic cutting. (3) Within the range of cutting depth in experiment, the influence of cutting d epth on the roundness error is more obvious in common cutting than that in ultra sonic vibration cutting. The conclusions are useful in machining such precise ul tra-thin wall parts. According to the tests, the following conclusions can be o btained: 1) Compared with common cutting, ultrasonic cutting can decrease effect ively roundness error of the workpiece. Under the same condition, the roundness error of the ultra-thin wall part in ultrasonic turning is about one third of t hat in common cutting. 2. In common cutting, cutting depth and feed rate have mu ch influence on the roundness and the influence of cutting velocity is little. W hile in ultrasonic cutting, the roundness was influenced heavily only when feed rate is more than 0.1 mm/r and cutting speed is more than 1/3 of the critical ro tation speed, cutting depth has little influence on the roundness in the experim ent. 3) Kerosene-oil is an optimum cutting fluid in machining ultra-thin wall workpiece.

关键词： ultra-thin wall part ultrasonic vibration cutt ing roundness guiding drawtube

Car-Parinello molecular dynamics simulations of thionitroxide and S-nitrosothiol in the gas phase,methanol,and water——A theoretical study of S-nitrosylation

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中国科学:化学 2012年第10期42卷 1497-1498页

作者： LIANG Juan1,CHENG ShangLi1,HOU JunWei1,XU ZhenHao1,2.& ZHAO Yi-Lei1,2.3* 1 State Key Laboratory of Microbial Metabolism,school of Life Sciences and Biotechnology,shanghai {2. tong {2.,shanghai 2.02.0,China 2.shanghai Center for Systems Biomedicine,shanghai {2. tong {2.,shanghai 2.02.0,China 3 MOE Laboratory of Scientific and engineering Computing,shanghai {2. tong {2.,shanghai 2.02.0,China State Key Laboratory of Microbial Metabolism school of Life Sciences and Biotechnology shanghai jiao tong university{2. China shanghai Center for Systems Biomedicine shanghai jiao tong university{2. China MOE Laboratory of Scientific and engineering Computing shanghai jiao tong university{2. China

A dilemma about whether thionitroxide radical(RSNHO) or S-nitrosothiol(RSNO) is observed in protein S-nitrosylation has arisen *** illustrate the effect of chemical environment on these structures,this paper presents quantum mechanical molecular dynamics of thionitroxide,and cis-and trans-S-nitrosothiols in the gas phase,methanol,and *** using Car-Parrinello molecular dynamics(CPMD),we have observed that there is free rotation about the S-N bond at 300 K in thionitroxide,but no such rotation is observed for *** C-S-N-O torsion angle distribution in thionitroxide is significantly dependent upon the surrounding environment,leading to either gauche-,cis-,or *** the case of S-nitrosothiol the C-S-N-O plane is twisted slightly by 5°-15° in the cis-isomer,while the periplanar structure is well-retained in the *** calculated results are in agreement with the X-ray crystallographic data of small molecular RSNO ***,for both compounds,the CPMD simulations show that solvation can cause a decrease in the S-N bond ***,the oxygen atom of thionitroxide is found to be a good hydrogen-bond acceptor,forming an oxyanion-hole-like hydrogen bonding network.

关键词： quantum mechanical molecular dynamics S-nitrosylation thionitroxide S-nitrosothiol solvent effect

Research on the Characters of the Cutting Force in Vibration Cutting Particle Reinforced Metal Matrix Composites SiC_p/Al

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厦门大学学报（自然科学版） 2002年第S1期41卷 74-75页

作者： LIU Chuan-shao 1, ZHAO Bo 1,2. GAO Guo-fu 1, jiao F eng 1 (1. Department of mechanical {2., jiaozuo Institute of Techno logy, Henan 454000, China 2. Institute of mechanical {2., shanghai jiaotong university, shanghai 2.0030, China)

In this paper, turning experiments of machining particle reinforced metal matri x composites(PRMMCs) SiC p/Al with PCD tools have been carried out. The cutting force characteristics in ultrasonic vibration turning compared with that in com mon turning were studied. Through the single factor experiments and multiple fac tor orthogonal experiments, the influences of three kinds of cutting conditions such as cutting velocity, amount of feed and cutting depth on cutting force were analyzed in detail. Meanwhile, according to the experimental data, the empirica l formula of main cutting force in ultrasonic vibration turning was conclude d. According to the test results, the cutting force is direct proportion to cutt ing depth basically according to the relation between cutting force and other fa ctors, which is similar to that of common cutting, so is the feed rate, but the influence is not so big. The influence of cutting speed is larger than that of f eed rate on cutting force because the efficient cutting time increases in vibrat ion cycle with the increase of cutting speed, which causes cutting force to incr ease. The research results indicate: (1) Ultrasonic vibration turning possesses much lower main cutting force than that in common turning when adopting smaller cutting parameters. If using larger cutting parameters, the difference will inco nspicuous. (2. There are remarkable differences of cutting force-cutting veloci ty characteristics in ultrasonic vibration turning from that in common turning m ainly because built-up edge does not emerge in ultrasonic turning unlike common turning in corresponding velocity range. (3) In ultrasonic vibration cutting, t he influence of cutting velocity on cutting force is most obvious among thre e cutting parameters and the influence of feed is smallest. So adopting lower cu tting velocity and larger cutting depth not only can reduce cutting force effect ively but also can ensure cutting efficiency. (4) The conclusions are usefu

关键词： composite SiC p/Al PCD tool ultrasonic vibrati on turning cutting force

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu Wei Zhang Peng-yue Wang Yi-xian Liu Xiang-yi jiao Ao-xiang Wan Cheng-gang Wang Guo-dong tong Shou-mei Xiong school of Materials Science and engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 2.0.31 MPa to 2.0.31 MPa(increased by 11.52.),and the elongation is enhanced from 3.72.to 6.34%(increased by 70.52.).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property