螺栓角钢钢节点的三维非线性有限元分析

对螺栓角钢钢节点半刚性连接采用非线性有限元分析方法 ,对连接中的主要构件的顶部、底部、腹板角钢、高强螺栓、梁翼缘、柱翼缘和柱翼缘加劲肋进行三维非线性有限元精细模拟 ,针对有无柱加劲肋、有无腹板角钢等几种连接的情况进行比较分析 ,探讨了螺栓角钢半刚性连接的受力性能。     

CuMgAl类水滑石的制备和表征

用盐-碱制备法合成了CuMgAl三元类水滑石化合物。探讨了原料配比、合成方式、水热处理温度和时间对合成过程的影响,筛选出合成HTLcs的适宜条件,并对HTLcs结构的热稳定性进行初步研究。结果表明,制备HTLcs主要取决于pH值,同时由于Cu2+的姜-太勒效应,合成结构单一的CuMgAl类水滑石要求原料配比中n(Cu)∶n(Mg)不得超过1.0,CuMgAl-HTLcs热稳定性较差,300℃焙烧2h结构破坏,600℃开始烧结,在300~500℃之间,随焙烧温度提高所得复合氧化物比表面积增大,最高可达200 m2/g。     

制度管理与自我平衡——浅谈高职学生的心理素质教育

心理健康不仅是时代发展对教育的必然要求,而且是实施素质教育的目标之一。为了培养高职学生良好的心理素质,针对高职学生心理素质存在的问题,就如何加强学生心理素质教育进行了探讨。     

低压直流供电电路中高压直流的产生

在由低压直流电源供电的电路中,往往电路的某些部位需要使用高于电源所供的电压,将电源所供的低压转换为较高的电压,常用的方法有3种:自举升压、电感升压、逆变升压。结合实际应用电路对各种升压方法从器件选择、升压原理、升压结果等诸方面进行分析、探讨,解决了总体供电电压不变时,局部高压产生的关键性问题。它对电子电器电路的设计人员有一定的启发作用,对优化电路、遴选器件有较强的参考价值。     

Operation of superconducting fault current limiter using vacuum interrupter driven by electromagnetic repulsion force for commutating switch

Using conventional high‐temperature superconducting wire, a model superconducting fault current limiter (SFCL) is made and tested. Solenoid coil using Bi2223 silver sheath wire is so made that inductance is as small as possible and a vacuum interrupter is connected in series to it. A conventional reactor coil is connected in parallel. When the fault current flows in this equipment, superconducting wire is quenched and current is transferred into the parallel coil because of voltage drop of superconducting wire. This large current in parallel coil actuates magnetic repulsion mechanism of vacuum interrupter. Due to opening of vacuum interrupter, the current in superconducting wire is broken. By using this equipment, current flow time in superconducting wire can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of parallel coil. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(1): 52–61, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20315     

Comment on Greenwood (2007): Solving the puzzle of structure/function relations in the aging brain?

Neuroimaging experiments have shown that prefrontal regions of the brain, which have the most age-related volume loss, are also the regions most likely to be more active in older adults than in younger adults. In an attempt to solve this puzzle, P. M. Greenwood (see record 2007-15625-001) has proposed a cascade that flows from age-related atrophy in the brain to changed processing strategies that result in plastic changes in regions adjacent and contralateral to the atrophic areas, culminating in greater functional activity. This hypothesis should stimulate research into these mechanisms and hopefully will ultimately inform researchers' ability to rehabilitate cognitive disorders in the elderly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

粘土矿物用于乙烯聚合催化剂的研究 Ⅰ.以凹凸棒石粘土为载体的乙烯聚合催化剂

研究了以凹凸棒石粘土为载体,负载TiCl4制备的乙烯聚合催化剂的结构、性能及制备规律。结果表明,催化剂中Ti的负载量随焙烧温度的提高而逐渐降低,聚合活性随焙烧温度的提高呈上升趋势,但过高的焙烧温度也会导致粘土晶体结构的彻底破坏而不利于活化粘土活性的提高;通过采用烷基铝等有机金属化合物处理粘土同样可以极大地改善粘土性质,提高催化活性。不同助催化剂对以凹凸棒石粘土为载体的催化剂的聚合性能有较大影响。     

弹力竹节牛仔布织造工艺优化

介绍了弹力竹节牛仔布的生产工艺 ,同时对KT36 8剑杆织机织造该织物的工艺进行了优化研究     

温度应力、自收缩对高性能混凝土早期开裂的影响

根据高性混凝土的水化特性、物理力学特性及自收缩特性，分析了高性能混凝土早期开裂机理和影响早期开裂的主要因素．并结合工程实例，借助混凝土温度和应力有限元仿真计算方法分析研究了表面适度保温和水管冷却技术在高性能混凝土温控防裂中的应用效果．研究结果表明，表面适度保温与水管冷却相结合能有效降低混凝土的内外温差，减小混凝土早期表面拉应力与后期内部拉应力，防裂效果明显，对类似的工程具有借鉴作用．     

一种考虑分布电容的模糊故障测距算法

提出了一种考虑分布电容的故障测距新算法。该算法基于微分方程描述的线路数学模型，利用单端信息对高压输电线路进行故障测距，保留了解微分方程算法的简单可靠、现实可行、不必考虑衰减直流分量和谐波及电网频率波动影响的特点，同时考虑过渡电阻和分布电容的影响，克服了传统解微分方程法中在经高阻接地故障时测距误差过大和忽略分布电容引起的故障定位不准确的缺点。为了检验算法的精度，进行了大量的动模实验。结果表明，算法原理正确并具有较高的测距精度。