变长线扫描选择性激光烧结快速成型工艺的质量和效率优势分析

本文分析变长线扫描选择性激光烧结快速成型工艺对点扫描工艺的质量和效率优势.对二者光学系统结构作分析对比,对焦斑和线束上的功率密度作计算对比.变长线扫描系统采用的扫描方式和聚焦元件使线束宽度小且恒定,线束功率密度与点扫描焦斑的相当.变长线扫描选择性激光烧结快速成型工艺的质量优势是明显的,效率比点扫描工艺提高一倍左右.     

Coal liquefaction using a hydrogenated creosote oil solvent: H-atom transfer from hydrogen donor components in the solvent

The presence of hydroaromatic, hydrogen donor components in a coal-derived solvent is one of the more important factors in the successful operation of a non-catalytic coal liquefaction process. Various hydrogen donor species present in a hydrogenated creosote oil have been identified. Their rate of disappearance under conditions that are consistent with a short residence time coal liquefaction process has been used to rank the reactivities of the various hydrogen donors. 1,2,3,10b-Tetrahydrofluoranthene was found to be an exceptional donor while 4,5-dihydropyrene, the hexahydropyrenes and 9,10-dihydrophenanthrene were found to be quite active. Sym.-octahydrophenanthrene and 2a,3,4,5-tetrahydroacenaphthene exhibited moderate activity. Tetralin and the four methyltetralin isomers were found to be unreactive under the coal liquefaction conditions employed.     

常用激光介质膜的斜入射性能

本文给出了多层介质膜反射率与入射角的关系的计算机程序，并列出了部份常用激光膜片反射率-角度曲线。     

防止减速器“跑,冒,漏”油的几种新方法

介绍了防止减速器“跑，冒，漏”油的几种新方法。     

Explicit robust schemes for implementation of a class of principal value-based constitutive models: Symbolic and numeric implementation

The issue of developing effective and robust schemes to implement a class of the Ogden-type hyperelastic constitutive models is addressed. To this end, special purpose functions (running under MACSYMA) are developed for the symbolic derivation, evaluation, and automatic FORTRAN code generation of explicit expressions for the corresponding stress function and material tangent stiffness tensors. These explicit forms are valid over the entire deformation range, since the singularities resulting from repeated principal-stretch values have been theorectically removed. The required computational algorithms are outlined, and the resulting FORTRAN computer code is presented.     

镀镍云母导电复合材料的研究

对云母粒子化学镀镍及以LDPE为基材,镀镍云母粒子为填料制备的导电复合材料进行研究。认为此种导电复合材料只有质量轻、强度大及良好的导电等性能。     

工业层析洗梯液回收套用的一种方法

以生产甲胺基阿维菌素苯甲酸盐精品的工艺——工业层析产生的洗梯液回收套用的过程为例，说明利用二元恒沸物的组成随压力的变化而变化的规律，对生产洗梯液进行有效、简洁、合理分离及套用的方法。     

不断创新管理机制努力做好学生工作

当我国的素质教育在知识经济崛起的世纪之交迅猛推进的时候,"如何才能全面有效地提高大学生的素质"就成为了教育者执着探询的重要课题.多年的教育实践使我们深深地认识到,全面推进素质教育就必须要坚持与时俱进,不断创新管理机制.具体来讲,就是要实施四个创新:     

连续流动分析仪应用于水中硫化物的测定

对连续流动法测定硫化物进行初步探讨和研究。同时与其他几种测定硫化物的方法进行了比较。实验结果表明，连续流动法对硫化物分析在线性、稳定性、最低检测限、准确性和精密度等方面均优于其他方法。     

我国耐高温非纤维素绝缘纸的现状和发展动向

绝缘纸是一种采用造纸工艺生产并广泛应用于变压器、电容器、电机、电线电缆等电气装备中的重要绝缘材料,按其组成可分为纤维素纸和非纤维素纸两大类.随着我国电力工业的持续发展,电机等用电设备逐步向高效小型化方向发展,故对绝缘纸的各项性能尤其是耐高温性能提出了更高的要求,纤维素纸虽然历史悠久,但耐热性不高,已无法满足耐热等级F级以上电气绝缘系统的使用要求,因此耐热性更高的非纤维素纸异军突起.本文简要介绍了我国各类耐高温非纤维素绝缘纸的研发历程、性能特点、主要用途、生产现状及发展动向.