地铁车站深基坑围护结构变形监测与数据分析

结合无锡地铁1号线梁东路地铁车站明挖法施工的具体情况,介绍了车站深基坑监测方案,并对围护结构水平位移和内支撑轴力监测数据进行分析,探讨位移和内支撑轴力随施工工况变化的规律及机理,为类似基坑作业提供借鉴。     

气体绝缘开关设备中特快速瞬态过电压研究的新进展

气体绝缘开关设备（gas insulated switchgear,GIS）中的隔离开关操作空载短母线会产生陡波前、高幅值的特快速瞬态过电压（very fast transient overvoltage,VFTO）、瞬态壳体电位和电磁干扰,对GIS及其连接的具有绕组的设备、与壳体连接的二次设备绝缘产生危害,干扰二次设备工作,严重影响设备的安全运行。对2009年前国内外在VFTO测量方法、特性试验、数字仿真和对绝缘影响以及外部VFTO方面的研究状况进行了综述。概要总结了国家电网公司在特高压GIS中VFTO实测及仿真研究方面取得的新进展,提出了特高压GIS中VFTO需要深化研究的内容,即重点关注VFTO的传播特性与仿真建模,VFTO下的绝缘特性和机制研究,以期全面掌握特高压GIS中VFTO特性,对特高压输变电设备的研制、工程设计和运行提供依据和有益的参考。     

催化裂化沉降器跑剂分析与对策

中国石化青岛炼油化工有限责任公司2013年3月发生沉降器跑剂事件,检查发现沉降器旋风分离器翼阀周围催化剂和焦块大量堆积是导致翼阀启闭异常、跑剂的主要原因,翼阀舌板磨损、穿孔和提升管出口旋流快分头上部箱体磨穿等问题也使跑剂现象加剧。采取改造沉降器封闭罩、割除封闭罩外承插部位、改造封闭罩溢流密封圈、取消封闭罩外蒸汽环和油气平衡管、增设封闭罩外侧盖板、更换新防焦蒸汽环、更换翼阀等一系列措施后,沉降器封闭罩外催化剂大量堆积、盖板以上区域封闭罩外壁及沉降器内壁结焦等难题得以解决,从根本上解决了沉降器跑剂问题。     

浅析朱赛普·特拉尼的代表作法西斯大厦

介绍了法西斯大厦的基本情况，通过对朱赛普·特拉尼的代表作法西斯大厦的空间结构、承重结构、围护结构、立面结构的分析，以使人们更深刻地理解特拉尼的建筑思想，探索其积极的现实意义。     

“重生意识”与中国传统建筑文化

中华民族因特殊的地理环境和长期历史积淀,形成了以“重生意识”为主体的民族性格特征,这种独特的民族性格对中国传统建筑的形成与发展产生了深刻的影响。文章通过对国家、风水、城市和院落的空间模式特性的探讨,指出其共同的特性—围合,并将不同层面上的空间模式纳入一个统一的框架,总结出“重生意识”下中国传统建筑空间图式—多重围合。同时,将物质建设活动延伸到社会文化层面,试图找出中国传统建筑空间模式与民族性格的内在关联。     

Coverage path planning for eddy current inspection on complex aeronautical parts

Non-destructive testing (NDT) plays a critical role in controlling the structural integrity (therefore the quality) of aeronautical parts, during fabrication as well as during maintenance. Eddy current (EC) testing is one of the most used NDT techniques in the aerospace industry. However, EC testing is still mainly performed by human operators and reliability as well as repeatability is not always guaranteed. To solve these issues, automating this NDT technique with a robotic system is investigated. In this paper, an EC probe equipped with a passive compliant system is assumed to be attached to the end-effector of a 6-DOF manipulator arm to carry on the inspection. Then, assuming that a 3D model of the inspected part is known a priori, a coverage path planning method using a zigzag (or rastering) pattern adapted to EC testing on aeronautical structures with a complex geometry is proposed. To reach this objective, the approach adopted in this work is to adapt existing coverage path planning techniques based on a “divide-and-conquer” strategy used for spraying applications to EC inspection. More precisely, three successive segmentations are applied to the surface to be inspected so that consistent rastering paths can be generated. Simulation results are shown for a complex part of an aeronautical structure to demonstrate the efficiency of the proposed method.     

基于改进型C4.5算法的关系数据库零水印模型研究

对传统的数据库数字水印技术进行分析,结合关系数据库零水印一般模型,提出一种基于改进型C4.5算法的关系数据库零水印模型。重点研究该模型关系数据库零水印构建算法并进行定性分析,发现算法具有更广的适用性和更好的鲁棒性。     

Performance analysis of hybrid/single nanofluids on augmentation of heat transport in lid-driven undulated cavity

This numerical study reveals the heat transfer performance of hybrid/single nanofluids inside a lid-driven sinusoidal trapezoidal-shaped enclosure. The right and left inclined surfaces of the trapezium have been considered as insulated, whereas the bottom sinusoidal wavy and the flat top surfaces of the enclosure as hot and cold, respectively. The governing partial differential equations of fluid's velocity and temperature have been resolved by applying the finite element method. The implications of Prandtl number (4.2-6.2), Richardson number (0.1-10.0), undulation number (0-3), nanoparticles volume fraction (0%-3%), and nanofluid/base fluid (water, water–copper (Cu), water–Cu–carbon nanotube, water–Cu–copper oxide (CuO), water–Cu–TiO₂, and water–Cu–Al₂O₃) on the velocity and temperature profiles have been studied. Simulated findings have been represented by means of streamlines, isothermal lines, and average Nusselt number of above-mentioned hybrid nanofluids for varying the governing parameters. The comparison of heat transfer rates using hybrid nanofluids and pure water has been also shown. The heat transfer rate is increased about 15% for varying Richardson number from 0.1 to 10.0. Blending of two nanoparticles suspension in base fluid has a higher heat transfer rate—approximately 5% than a mononanoparticle. Moreover, a higher average Nusselt number is obtained by 14.7% using the wavy surface than the flat surface of the enclosure. Thus, this study showed that applying hybrid nanofluid may be beneficial to obtain expected thermal performance.     

修正三角模糊事故树算法在化工生产事故预测中的应用

基于传统三角模糊事故树预测模型存在因线性近似导致误差较大的不足,通过截集定理分析了误差的来源,根据表现定理给出了事故树顶上事件三角模糊数隶属度曲线绘制的改进算法。使用MATLAB软件编制程序,分别采用修正的和传统的三角模糊事故预测算法,针对油库静电积累事故进行预测,计算8个原因事件的模糊重要度。计算结果显示,与传统算法相比,修正算法8个基本事件的模糊重要度计算误差平均降低11.91%,表明修正算法极大地优化了传统算法的不足。