现代化小型冷床上料装置结构设计分析及计算

近年来，由于轧钢工艺趋向于采用无扭轧制等先进技术，使轧制速度迅速提高，对冷床高速上料装置提出了更高的要求。冷床高速上料装置是冷床设计中的难点，也是关键设备，它的设计质量与安装精度直接决定着产品的最终质量。本文对冷床高速上料装置进行了结构分析与计算，对冷床的设计、维护有一定的指导意义。     

Analysis of singular stress fields at multi‐material corners under thermal loading

The scaled boundary finite‐element method is extended to the modelling of thermal stresses. The particular solution for the non‐homogeneous term caused by thermal loading is expressed as integrals in the radial direction, which are evaluated analytically for temperature changes varying as power functions of the radial coordinate. When applied to model a multi‐material corner, only the boundary of the problem domain is discretized. The boundary conditions on the straight material interfaces and the side‐faces forming the corner are satisfied analytically without discretization. The stress field is expressed semi‐analytically as a series solution. The stress distribution along the radial direction, including both the real and complex power singularity and the power‐logarithmic singularity, is represented analytically. The stress intensity factors are determined directly from their definitions in stresses. No knowledge on asymptotic expansions is required. Numerical examples are calculated to evaluate the accuracy of the scaled boundary finite‐element method. Copyright © 2005 John Wiley & Sons, Ltd.     

大学的教学方法必须改革

目前,社会和经济发展对人才的需求发生了很大变化,学校教育方式的变化没有跟上社会发展对人才需求的变化.通过几年教学方法的改革和探索,我们培养了很多满足社会需求的人才,本文论述了进行教学方法改革的体会.     

基于VB6.0的汽车点火线圈测试系统软件设计

VB因其简单易学，功能强大而倍受测控软件开发人员的青睐。本文针对作者在开发点火线圈测试台软件的过程中遇到的重点、难点问题—串口通讯、端口读写、数据库操作等，介绍了用Visual BasiC 6．0实现的方法。     

Strain rate sensitivity of tensile properties in high Nb containing TiAl alloys

The effect of strain rate on the yield strength of high Nb containing TiAl alloy was studied. The results show that the strain rate sensitivity varies with the test temperature, and the yield strength is not sensitive to the strain rate at room temperature but significantly sensitive to the strain rate at high temperature. An increase of the strain rate or a decrease of the temperature results in an obvious change of fracture mode. It is found that the strain rate sensitivity of this alloy varying with temperature is due to the dislocation climb generated at high temperature.     

海洋环境下船用空调现状及发展探讨

本文介绍了海洋环境下船用空调的特殊性,指出风机的选择对于保证空调系统运行是非常重要的,从环保和节能的角度出发认为采用吸收式或吸附式制冷是船用空调发展的一个方向.     

攀钢镀锌线退火炉辐射管应用特点及其性能分析

介绍了攀钢连续热镀锌机组中退火炉辐射管的应用特点，并对U型辐射管和W型辐射管的热效率、表面温度分布及使用寿命等技术性能进行了深入的分析。     

室温固相反应法制备纳米氧化锆及表征

以ZrOCl2.8H2O和NH4HCO3为原料,在适量表面活性剂(PEG-400)存在下,先在室温下充分混合研磨进行固相反应,得到的反应混合物再用水洗去其中的可溶性无机盐并烘干,即得氧化锆前驱体。前驱体经530℃下热解3h即得氧化锆产品,采用TG/DTA,XRD和TEM对前驱体及产品进行了表征。结果表明,所得产品氧化锆为结晶良好、以四方相为主的混合晶相,其平均粒径约为25nm。     

四次有理Bézier曲线的形状调整

给出了一种基于权因子调整的四次Bézier 曲线形状控制的有效方法。推导出了曲线肩点的两种新的表达式。这两个表达式对曲线权因子的意义进行了较好的解释,很好地反应出权因子变化对曲线肩点位置的影响。基于这两个表达式,推导出了曲线肩点插值某固定点时各权因子的具体取值公式。最后,实例表明此方法能给曲线形状调整带来实用性指导。