检索结果-南通市图书馆

Formal analysis and design of multi-party fair exchange protocols

在线全文

学校读者我要写书评

暂无评论

Science in china(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1,2,3.& LI Gaicheng1,3.1. engineering research Center for Information Security Technology, institute of Software,{3., Beijing 100080, china 2. Beijing Zhongke Ansheng Corporation of Information Technology, Beijing 100080, china 3. Graduate School of the{3., Beijing 10003., china 1. engineering research Center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. Beijing Zhongke Ansheng Corporation of Information Technology Beijing 100080 China 3. Graduate School of the chinese academy of sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

MICROSTRUCTURE，INTERFACE　AND　MECHANICAL　PROPERTIES　OF　NiAl－BASED　COMPOSITES　REINFORCED　BY　TiB_2　PARTICULATES

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1995年第Z1期8卷 455-465页

作者： GUO Jianting(institute of Metal research, chinese academy of sciences, Shelving 110015,{3.)XING Zhanping(School of Materials Science and engineering, Harbin institute of Technology, Harbin 150001,{3.) Inst of Metal research chinese Acad of Sciences Shenyang China

This paper developed a hot Pressing aided exothermic synthesis (HPES) technique. to fabricate NiAl matrix composites containing 0 and 20 v.% TiB_2 particles. The conversion to the product was complete. and TiB_2 particles in the matrix were uniformly dispersed. The inter faces between nail and TiB_2 were atomically flat. sharp and free from any inter facial phases in most cases. In some cases. however. thin inter facial amorphous layers existed at NiAl/ TiB_2 interfaces. In addition, the microstructure and inter faces were highly thermal stable. In all processing states. the yield strengths at room temperature or at 1000℃ of the composite were approximately three times as strong as that of the unrein forced NiAl. The ambient fracture toughness of the composite was also superior to monolithic NiAl.

关键词： intermatallic matrix composite NiAl-TiB_2 microstructure interface,mechanical property

Surface Modification of Ceramic Materials Using Excimer Laser

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2000年第4期16卷 401-404页

作者： Yingna WU, Zhongchao FENG and Jing LIANG (institute of Metal research, chinese academy of sciences, Shenyang 110015,{3.) institute of Metal research Chinese Academy of Sciences Shenyang 110015 China

Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3. Al2O3.SiC nanocomposite and Si3.4). Al2O3.and AI2O3.SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3.4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3. Al2O3.SiC nanocomposite and Si3.4 was improved to various degrees: Al2O3.SiC nanocomposite, 60% (max.); AI203. 40% (max.); Si3.4, 12% (max.).

关键词： Surface Modification of Ceramic Materials Using Excimer Laser SiC

Recombinant Bivalent Vaccine against Foot-and-Mouth Disease Virus Serotype O/A Infection in Guinea Pig

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第9期36卷 589-596页

作者： Jian-Zhong YI1, Ming-Qiu LIU1, Cai-Zhu ZHU2, Qiang ZHANG1, Zu-Tian SHENG3. Qing-Yun DU3. Wei-Yao YAN1, and Zhao-Xin ZHENG1* State Key Laboratory of Genetics engineering, Life Science School, Fudan University, Shanghai 20043., china 1The Veterinary institute of {3. academy of Agricultural sciences, lanzhou 73.046, china 2The Virus research institute of Zhejiang academy of Agricultural sciences, Hangzhou 3.0021, china State Key Laboratory of Genetics engineering Life Science School Fudan University The Veterinary institute of chinese academy of Agricultural {3.

In this study, two DNA fragments encoding amino acid (141–160)-(21–40)-(141–160) of the VP1 of FMDV (foot-and-mouth disease virus) serotype O and (13.–160)-(21–40)-(13.–160) of the serotype A FMDV were chemically synthesized. These two tandem-repeat fragments were ligated and transfected into prokaryotic expression vector pTrcHis A to construct pTH-O-A. The other vector called pTH-O-scIgG-A was constructed similarly only that the two tandem-repeat DNA fragments were linked by the bovine- IgG heavy chain coding sequence. Guinea pigs immunized with the two bivalent vaccines pTH-O-A and pTH-O-scIgG-A showed both specific antibody activity and T cell proliferation responses. FMDV challenge tests showed that 85% and 70% of guinea pigs vaccinated twice with 200 μg of the fusion protein of pTH-O-A were protected from FMDV serotype O and serotype A infection respectively. 70% and 57% of the guinea pigs immunized with the fusion protein of pTH-O-scIgG-A were protected from FMDV serotype O and serotype A infection respectively.

关键词： foot-and-mouth disease FMDV serotype O FMDV serotype A VP1 protein bivalent vaccine guinea pig

SILICA-SUPPORTED NICKEL AND ZIRCONIUM CATALYSTS FOR BRANCHED POLYETHYLENE

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2003年第4期21卷 453-458页

作者：孙文华 State Key Laboratory of engineering Plastics The Center for Molecular sciences institute of Chemistry {3. academy of sciences Beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Engn Plast Beijing 100080 Peoples R China

8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp_2ZrCl_2) were supportedsimultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supportedpolymerization results showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2ZrCl_2 and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.

关键词： 8-Aminoquinoline nickel dichloride, Cp_2ZrCl_2 Silica supported catalysts Branched polyethylene

Flow Instability and Its Control in Compression Systems

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第1期12卷 1-9页

作者： Jingyi Cheninstitute of engineering Thermophysics, chinese academy of sciences, Beijing 100080,{3. institute of engineering Thermophysics Chinese Academy of Sciences Beijing China

This paper reviews the development in the research of flow instability and its control over the recent ten or more years. This development was largely stimulated by the novel idea of active control of the aerodynamic instability in compressors. Three topics are covered in the paper, which appeared as the major themes towards the goal of stability enhancement. The first topic is the pre-stall behavior of rotating stall, which plays a vital role in designing the control scheme and discovering the convenient route to find the causal factors of flow disturbances potentially leading to stall. The second topic is the mechanism of blade passage flow during stall and its inception, which is the basic knowledge needed to manipulate the blade design for the stability improvement and eventually to predict the unsteady performance of the compressor system. The third topic is the recent trend of the control strategy based on the learning of active vs. passive methods. To introduce to the discussion of these topics, a brief description of the history of the recent development is given at the beginning of the paper. In discussing each topic, future works are also highlighted to enhance the further development of this long-standing problem in turbomachinery research and application.

关键词： compressors rotating stall pre-stall active/passive control wavelet.

Anomaly feature of seasonal frozen soil variationson the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical sciences 2002年第1期12卷 99-107页

作者： WANG Cheng-hai1,2, DONG Wen-jie3. WEI Zhi-gang2 (1. College of Resource and Environmental Science, lanzhou University, lanzhou 73.000, china 2. {3. and arid regions Environmental and engineering research institute, CAS, lanzhou 73.000, china 3. Insti College of Resource and Environmental Science Lanzhou University Lanzhou 730000 cold and arid regions Environmental and {3. research institute CAS Lanzhou 730000 institute of Atmospheric Physics CAS 北京 Beijing

The seasonal frozen soil on the Qinghai-Tibet Plateau has strong response to climate change, and its freezing-thawing process also affects East Asia climate. In this paper, the freezing soil maximum depth of 46 stations covering 1961–1999 on the plateau is analyzed by rotated experience orthogonal function (REOF). The results show that there are four main frozen anomaly regions on the plateau, i.e., the northeastern, southeastern and southern parts of the plateau and Qaidam Basin. The freezing soil depths of the annual anomaly regions in the above representative stations show that there are different changing trends. The main trend, except for the Qaidam Basin, has been decreasing since the 1980s, a sign of the climate warming. Compared with the 1980s, on the average, the maximum soil depth decreased by about 0.02 m, 0.05 m and 0.14 m in the northeastern, southeastern and southern parts of the plateau, but increased by about 0.57 m in the Qaidam Basin during the 1990s. It means there are different responses to climate system in the above areas. The spectrum analysis reveals different change cycles: in higher frequency there is an about 2-year long cycle in Qaidam Basin and southern part of the plateau in the four representative areas whereas in lower frequency there is an about 14-year long cycle in all the four representative areas due to the combined influence of different soil textures and solutes in four areas.

关键词： Qinghai-Tibet Plateau seasonal frozen soil rotated empirical orthogonal function analysis anomaly areas

Cooling effect of ripped-stone embankments on Qing-Tibet railway under climatic warming

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2003年第6期48卷 598-604页

作者： LAI Yuanming1, ZHANG Luxin1 , ZHANG Shujuan1 & MI Long2 1. State Key Lab. of Frozen Soil engineering, cold and arid {3. Environmental and engineering research institute, chinese academy of sciences, lanzhou 73.000, china 2. Department of Civil engineering, Northern Jiaotong University, Beijing 100044, china State Key Lab. of Frozen Soil engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Department of Civil engineering Northern Jiaotong University Beijing China

The heat convection in ballast mass and ripped-stone mass in railway embankments is the problem of heat convection in porous media. In order to calculate the temperature distribution of Qing-Tibet railway embankment, from the governing equations used to study forced convec-tion for incompressible fluids porous media, the finite ele-ment formulae for heat convection in porous media are de-rived by using Galerkin抯 method. The temperature fields of the traditional ballast embankment and the ripped-stone mass embankment, constructed on July 15, have been ana-lyzed and compared under the case that the air temperature in Qinghai-Tibetan Plateau will be warmed up by 2.0℃ in the future 50 years. The calculated results indicate that, the permafrost 5 m below the traditional ballast embankment will be thawed in the regions in which the air yearly-average temperature is larger than -3.5℃ or the yearly-average temperature at the native surface is larger than -1℃. The embankment will cause large thawing settlement. The rail-way embankment will be damaged by permafrost degrada-tion. The ripped-stone mass embankment can not only resist the effect of climatic warm up on it but also provide cool energy for the permafrost under it. It can assure permafrost stability and not subjected to thawing. Therefore, it is highly recommended that the ripped-stone mass embankment be taken as the Qing-Tibet railway embankment structure in high-temperature permafrost regions so that permafrost embankment can be protected as possible as we could.

关键词： cooling effect ripped-stone embankment climatic warming.

Unsteady Numerical Simulation of Hot Streak/Blades Interaction and Film Cooling

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第5期19卷 402-409页

作者： Weilin Yi,Lucheng Ji and Yunhan Xiao research Center for Energy and Power,chinese academy of {3.,Beijing,china Key Laboratory of Advanced Energy and Power,chinese academy of {3.,(institute of engineering Thermophysics),Beijing,china P.O.Box 2706,Beijing 100190,china research Center for Energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China Beijing China

Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot *** method is a useful instrument to investigate the correlative *** the paper developed independently three dimensional unsteady parallel computational code-MpiTurbo based on Fortran 90 and MPI at Linux operating *** unsteady numerical simulation was carried out to investigate impacts of the factors,which included circumferential locations of hot streak and clocking positions of blade rows,on the thermal environment of a 1+1 counter-rotating *** results clearly indicated that clocking positions of hot streak/blade row and blade row/blade row had great influence on the time-averaged temperature distribution of the third blade ***,it can be effective for improving thermal environment of turbine to optimize blade parameters and clocking *** film cooling layout was designed by the repetitious steady simulation based on source term *** the flow structure detail was given by the unsteady simulation.

关键词： hot streak turbine parallel computation film cooling