知识管理研究

知识管理是知识经济时代政企单位运作的主要管理体系和管理工具。本文结合大型企业综合信息系统设计实践经验，针对我国目前政府和企业信息化建设现状，对知识管理系统建设过程中的一些问题，提出了几点初步的设想。     

Numerical method for simulating tire rolling noise by the concept of periodically exciting contact force

For the numerical simulation of tire rolling noise, an important subject is the extraction of normal velocity data of the tire surface that are essential for the acoustic analysis. In the current study, a concept of periodically exciting contact force is introduced to effectively extract the tire normal velocity data. The ground contact pressure within contact patch that is obtained by the static tire contact analysis is periodically applied to the whole tread surface of stationary tire. The periodically exciting contact forces are sequentially applied with a time delay corresponding to the tire rolling speed. The tire vibration is analyzed by the mode superposition in the frequency domain, and the acoustic analysis is performed by commercial BEM code. The proposed method is illustrated through the numerical experiment of 3-D smooth tire model and verified from the comparison with experiment, and furthermore the acoustical responses are investigated to the tire rolling speed.     

强基固本筑牢公交发展根基

“基础不牢，地动山摇”。没有强有力的基层就难以落实好各项工作。新时期，要推进公交企业持续健康发展，必须本着继承与创新相结合原则，通过抓基层、打基础、苦练基本功，真正增强基层实力，提高队伍素质，提升管理水平。近年来，大庆油田公共汽车公司继承发扬大庆精神、铁人精神，坚持从公交行业特点和企业实际出发，创新工作，强基固本，着力加强基层文化建设、队伍建设和机制建设，全公司基层建设整体水平不断提高，公司先后荣获“全国职业道德建设十佳单位”、“全国城市公共交通文明企业”和“全国建设系统企业文化建设先进单位”等荣誉称号。     

Feasibility study for the application of air inflated membrane structure in China National Stadium

China National Stadium, also known as “Bird’s Nest”, is the main stadium of the 29th Olympic Games in Beijing in 2008, which has successfully held not only the Opening and the Closing ceremonies but also the track and field events. A new problem of rain preventing is brought out to improve the utilization of the Bird’s Nest after the Olympic Games. The scheme of installing an air inflated membrane at the opening of the steel structure is proposed in this paper to solve the rainproof problem of the Bird’s Nest. The form-finding and mechanical analyses of the air inflated membrane are carried out. Comparison between the mechanical performance and dynamical character before and after installing the air inflated membrane structure is given. To verify the analysis results, based on the practical structure of the Bird’s Nest, a test of a 1:20 model membrane is worked out.     

在R＜250m小半径曲线上铺设特种混凝土轨枕

金城江工务段管辖的黔桂线金城江～麻尾区段,地处桂西北山区,系解放前修建的一条技术标准极低的山区铁道线,沿线山峦起伏,线路沿山盘绕.全长151.6km正线中,共有曲线302个,其中半径≥250m的曲线有170个;半径＜250m的曲线有132个,延长78.8km,占正线全长52.0%;曲线最小半径为175m……     

施工风险管理的探讨

通过对施工风险及管理的阐述,提出施工风险管理中应注意的问题,并说明将风险管理理论和方法引入工程施工中的可行性.     

基于CAD系统的配气机构凸轮改进设计

内燃机配气机构的性能在很大程度上取决于配气凸轮的结构,而凸轮轮廓线设计的好坏对发动机的充气性能和动力性能的影响更大,借助于计算机辅助设计可以较好地解决这个问题     

城轨交通EI32-JDC型计算机联锁系统

介绍应用于城市轨道交通的EI32-JDC型计算机联锁系统结构、主要技术参数及性能。     

Exact and simplified estimations for elastic buckling pressures of structural pipe-in-pipe cross sections under external hydrostatic pressure

Structural pipe-in-pipe cross sections have significant potential for application in offshore oil and gas production systems because they combine thermal insulation performance with structural strength and self weight in an integrated way. Such cross sections comprise inner and outer thin-walled pipes with the annulus between them fully filled by a selectable filler material to impart an appropriate combination of properties. Structural pipe-in-pipe cross sections can exhibit several different collapse mechanisms, and the basis of the preferential occurrence of one over the others is of interest. This article presents an exact analysis for predicting the elastic buckling behaviours of a structural pipe-in-pipe cross section when subjected to external hydrostatic pressure. Simplified approximations are also investigated for elastic buckling pressure and mode when the outer pipe and its contact with the filler material is considered as a pipe on an elastic foundation. Results are presented to show the variation of elastic buckling pressure with the relative elastic modulus of the filler and pipe materials, the filler thickness, and the thicknesses of the inner and outer pipes. Case studies based on realistic application scenarios are used to show that the simplified approximations are sufficiently accurate for practical structural design purposes.