BIMORPH PIEZOELECTRIC ACTUATOR FOR SMALL PIPE ROBOT

An experimental bimorph piezoelectric element (PZT) actuator for small pipe robot is developed. The robot can move in φ20 mm pipe, and can carry a CCD camera for detecting cracks or fine holes on inner surface of pipe. The velocity of the robot can reach 17～22 mm/s for vertical pipe up/down, respectively. Moving principle and its performance characteristics are presented.     

1100℃以上高温连铸板坯表面缺陷的模拟在线无损检测

高温状态下连铸板坯表面缺陷的在线无损检测在现代化的连铸坯热送－直轧工艺中对于保证铸坯的质量有着极其重要的意义。本文介绍了连铸坯高温探伤技术和相应的试验装置。采用涡流方法成功地模拟了１１００℃以上铸坯表面缺陷的动态检测，所用探头及检测设备均可在高温状态下长时间连续工作，能检测出深度为１．５ｍｍ，宽度为０．３ｍｍ，长为１０ｍｍ的表面缺陷，并能有效地抑制铸坯表面振动斑痕所产生的噪声影响。借助于计算机信号     

聚乙烯基吡咯烷酮的生产与市场

文章介绍了聚乙烯基吡咯烷酮国内外生产现状、市场需求和发展趋势，重点介绍其合成技术进展与应用，并就其发展提出一些建议。     

基于B点磁探针膛内电枢电弧长度与速度分布测量的计算机控制系统的研究

基于B点磁探针的测量原理，建立了电磁轨道炮膛内三维等离子体电枢电弧长度和电弧运动速度测量的数学模型，通过对该模型的分析给出了用于测量膛内电枢电弧长度和运动速度分布的相应推论。开发了用于测量膛内等离子体电枢电弧长度和速度的多通道计算机控制诊断系统，并进行了相应的试验研究。     

A Survey of E-Commerce Security

E-commerce is a very active field of Internet research. A very important aspect of e-commerce is its security. Because of the variety of e-commerce applications, many security policies, protocols and techniques are involved in the deployment of the security. The related standards and protocols of e-commerce are studied in this paper. The general model of e-commerce security is set forth. In this model, two most important e-commerce protocols including secure sockets layer (SSL) and secure electronic transaction (SET) are analyzed. The open problems and new trends of e-commerce security are presented.     

FBOLES—outline of a frequency-based on-line expert system approach for fault diagnoses in nuclear power plants

The basic concept of a novel frequency-based on-line expert system (FBOLES) approach for on-line fault diagnoses in nuclear power plants has been presented previously. This paper reports further progress, and includes how to express the uncertainties of expert opinion in knowledge-bases and propagate then in inferences, and how to deal with imperfect knowledge-bases. It also describes the main elements of FBOLES and outlines how the system works under complex conditions including the dynamic behavior of signals during accidents, multiple failures, and on-line changes of plant operation mode. Its ability to diagnose root causes of accidents has been tested using the main steam and feedwater condensate systems of a full-scale, three-loop, 950 MW nuclear power plant simulated by the Tsinghua simulator. So far the results seem good.     

高硬度耐磨电弧喷涂管状丝材的研究

利用自熔性合金与非晶态材料的特点，研制了Fe—B系管状丝材作为电弧喷涂材料，其形成的涂层具有良好的结合强度、低的孔隙率、高的硬度和耐磨损性能。     

马克法输铝管用胶结剂的研制及应用

用粘土熟料、软质粘土及复合结合剂研制的胶结剂,用于马克法铸钢输铝管系统的胶结,其使用性能和使用寿命达到或超过了进口胶结剂的水平。     

基于熵权的料场方案模糊多属性优选研究

砂石料场方案选择中存在着许多难以精确度量的模糊性因素，常规的平衡法、系统分析法很难对此进行有效的处理。将模糊数学理论应用于砂石料场的方案选择，提出了熵权与模糊理论相结合的砂石料场方案优选方法，重点对标准化属性矩阵的产生、主客观权重结合得到综合权重及相对接近度的计算等几个方面进行了说明，并通过实例验证了该方法的可行性与实用性。     

乳液聚合螺旋半园管夹套反应釜

本文将螺旋半园管夹套反应釜与传统的夹套反应釜进行了对比 ,并介绍了螺旋半园管夹套釜在乳液聚合中的应用