三峡工地高压供电线路故障判断方法的探讨

高压供电设备故障特别是输电线路的高压接地故障对工地的影响是相当大的。由于接地故障为隐性故障，没有明显的物理现象，且若是长期接地可能会发展成较为严重的两相或三相短路故障，使系统解列运行直至崩溃；由于工地流动人员较多，还易造成电击事故。利用高压一相接地时在线路中产生零序电压这一特性来迅速判断和切除接地的用电设备，可以保证各项施工的顺利进行。     

双头螺栓失效分析

与汽车电机装配在一起的双头螺栓在拧紧后不久便发生断裂。采用扫描电镜、化学分析、金相检验等方法对失效件进行了检测，同时又进行了氢脆试验验证。结果表明，螺栓在进行表面酸洗及电镀时，氢向金属内部扩散和富集，当氢浓度达到一定临界值后，促使氢致裂纹的产生和扩展。在外应力的作用下，即出现氢脆现象导致螺栓断裂。     

TRVs and fault clearing stresses in extra-high-voltage radial networks

To cope with the high rate of increase of power demand in the main industrialized districts in Japan, 550-kV transmission systems covering the districts have been reinforced, with most of the main power plants connected directly to these systems. Through 550-/300-kV substations, the majority of power to the districts is supplied by 300-kV systems. To limit the excess short-circuit capacity in the 300-kV systems, they tend to be reconstructed as so-called radial networks. In radial networks with high short-circuit capacity and relatively small number of transmission lines connected to the substation busbars, the rate of rise of TRV can be far higher than standard value. This paper analyzes the transient recovery voltages (TRV) in such extra-high-voltage radial networks in Japan, together with the relevant stresses to circuit-breakers during fault clearings. Future system conditions have also been introduced. As the typical rate of rise of the TRV values, more than twice that of today's standard ones are probable.     

有杆泵抽油系统可靠性分析

抽油机井有杆果采油装置检泵故障数据的特点在于相邻两次检泵间隔之间的时间并非总是来自同一总体，可能有某种趋势的变化。通过对故障数据的趋势性检验，可验证其对某一随机过程模型的适应性，从而判定某一口井或某一批工况大致相同油井的运行可靠性，实现对生产井运行可靠性的定量评估。还通过实例说明了有杆泵抽油系统检泵故障数据的可靠性分析方法。     

复合材料压缩破坏模式的缺陷敏感性

本文基于弹塑性分叉理论研究单向纤维增强复合材料的压缩破坏模式和压缩强度对缺陷的敏感性问题。对于常见复合材料,所得结论是:无缺陷或者小缺陷情况的破坏模式为倾斜破坏带;大缺陷情况的破坏模式为水平破坏带;形成水平破坏带的压力值小于形成倾斜破坏带的压力。     

硅压力传感器的可靠性测试

硅压力传感器的可靠性测试技术研究受到了国内外的重视，对它的测试项目及其加速寿命测试方法进行了综述。     

在役油气管道安全评定软件

PSAforWindows是运行在Windows系统下的油气管道安全评定软件。该软件既可以用于在开挖中发现的管道局部缺陷的剩余强度的精确评定 ,又可以用于腐蚀检测之后对管道全线的安全评定与剩余寿命预测。软件中采用了非线性有限元分析、失效评定图和概率性的评定方法等最新成果。介绍该软件的结构、模块、软件特点、主要功能和操作界面     

"I know, you know": Epistemic egocentrism in children and adults.

This article reviews the evidence and theory pertaining to a form of perspective-taking failure--a difficulty in setting aside the privileged information that one knows to be unavailable to another party. The authors argue that this bias (epistemic egocentrism, or EE) is a general feature of human cognition and has been tapped by 2 independent and largely uncommunicating research traditions: the theory-of-mind tradition in developmental psychology and, with more sensitive probes, the "heuristics and biases" tradition in the psychology of human judgment. This article sets the stage for facilitating communication between these traditions as well as for the recognition of EE's breadth and potential interdisciplinary significance. The authors propose a life-span account and a tentative taxonomy of EE; and they highlight the interdisciplinary significance of EE by discussing its implications for normative ethics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

φ140mm套管拔套侧钻工艺技术在濮城油田的应用

濮城油田开发后期,因事故导致损坏的井数不断增多,不仅损失了相当一部分储量,而且严重威胁着油田的发展。针对这一问题,应用拔套侧钻工艺技术对有潜能的事故井进行侧钻更新,投产后取得了良好的效果,成为油田增储上产和挖潜剩余油的重要手段,同时也为解决困扰油田发展的难题找到了好的方法。     

锅炉未焊透椭圆接管结构应力数值分析

应用有限元法对未焊透的椭圆接管结构进行了应力数值分析,并应用压力容器分析设计法,对该结构进行了疲劳分析,得出结构因未焊透缺陷导致疲劳破坏。