胶层厚度对拉伸试样应力分布影响的数值分析

运用弹塑性有限元法研究了胶层厚度对承受拉伸载荷的对接接头胶层内应力分布的影响．三维有限元法数值分析的结果表明，随胶层厚度减小，胶层中正应力SZ与剪应力SYZ的分布趋于均匀；而对正应力SY而言，胶层厚度为0．15mm时，其边缘峰值应力最低。     

Dipole moments of copolymers in relation to the distribution of polar monomer unit sequences

A method for evaluating the dipole moments of copolymers in relation to the distribution of polar unit sequences is proposed. Experimental data on the synthesis and dipole moments of styrene-p-chlorostyrene and styrene-p-methoxystyrene copolymers were used to calculate the effective dipole moment of a polar unit in a copolymer. For this purpose, we assumed the following effective moment values for the corresponding polar unit sequences along the copolymer chains: when both of the nearest neighbours are polar, μ_PP, when one of the nearest neighbours is polar and the other is non-polar, μ_PS, and when both of the nearest neighbours are non-polar, μ_SS. The relative magnitudes of μ_SS, μ_PS and μ_PP calculated for both copolymers reflect the influence of dipole-dipole interactions on the effective dipole moment of a polar unit in a copolymer molecule.     

多维超几何分布的最可能成功数

超几何分布是一种重要的离散型概率分布,本文利用反证法以及比较法求出了三维超几何分布的最可能成功次数,并在此基础上,求出了多维超几何分布的最可能成功次数.     

变电站远程监控系统研究

研究了分布式Web计算技术开发远程监控系统的关键技术,就基于IP网络实现变电站远程监控的主要思路和技术问题进行说明和分析讨论.从信道带宽、网络机制、远动协议、信息安全等多方面讨论了IP网络传输时保证远动QoS的措施方法以及IP网络传输对信息安全的防护措施.     

片上网络中有保障服务的性能评估

本文针对如何评测片上网络中的有保障服务(Guaranteed-Services,GS)对尽力而为(Best-Effort,BE)流量的传输性能的影响进行了研究,提出了评测重点及相关性能指标,给出了构建网络流量的方法,采用了一种分层逐级抽象的方法搭建了支持任意拓扑结构、任意规模、多种网络协议的性能评估平台,实现了对片上网络中GS服务的性能评估.评测实例的结果表明该平台达到了评价片上网络中GS服务的服务质量和分析GS服务对网络整体性能的影响的目的,有效的帮助设计者在保障局部服务质量的同时提高网络性能,为设计优化提供了依据.     

供水管网水质模型校核面临的问题及对策

为解决大规模供水管网系统水质模型校核的难题,分析经验校核与自动校核所面临的问题,提出遗传算法并行化、实测确定模型初始参数、模型参数的有效分组等相应的对策.从而减少模型校核的变量,提高遗传算法运行效率,有效缩短模型自动校核的寻优时间.     

Corner forming of AZ61A magnesium alloy tube within warm hydroforming

The corners with small radii on cross sections are crucial for forming hydroformed components with polygonal sections.In this paper,warm hydroforming experiments of AZ61A magnesium alloy tubes were carried out to study the forming regularity of round corners by using a demonstration part with square sections.Effects of temperature on radius forming,thinning ratio distribution and microstructure were revealed and a component with relative outer corner radius of 3.0 was obtained by warm hydroforming at 240℃.The minimum thickness of the formed square section was located in the transition position between the corner and the straight wall.The thinning ratio of the round corner increased with the increase of forming temperature.Formability of the magnesium tube was improved by raising temperature under the effect of dynamic recrystallization at 240℃.     

相关分析在QC小组活动中的应用

QC小组将安阳卷烟厂2007年7月的质量报表中＂松散回潮工序后室温度过程能力指数小于1.33＂,不能满足要求的问题作为研究课题,通过现状调查,并将调查数据绘在散布图上,利用散布图了解到松散回潮工序前室温度标偏和后室温度标偏之间具有高度的线性相关,通过相关分析,确定了前室温度波动大是影响后室温度波动大的症结.通过实施相关对策使后室温度的过程能力指数满足要求.通过相关分析不仅准确地找出了问题的症结,而且提升了QC成果的水平.     

铒离子注入晶体硅的射程分布和离散研究

用400 keV能量的铒离子垂直注入晶体硅(Si)样品中。利用卢瑟福背散射技术研究了能量为400 keV、剂量为5×1015ions/cm2的铒离子注入Si晶体的平均投影射程、射程离散和深度分布。测出的实验值和TRIM 98得到的理论模拟值进行了比较,发现实验值跟TRIM 98模拟计算的理论值符合较好。     

配电网金属氧化物避雷器的选择

文章阐述了配电网金属氧化物避雷器选择的基本内容,给出了选择结果.