改性壳聚精膜用于醇水混合液分离的研究──Ⅲ．超细粉末填充壳聚精膜

首次制备了用Ｓｉ３Ｎ４，ＳｉＯ２，ＴｉＨ４超细粉末填充的改性壳聚精膜，并将其用于乙醇／水混合液的分离中。实验表明壳聚糖膜经超细粉末填充后强度增大，溶胀度减小。用于乙醇／水混合液渗透蒸发分离时，分离因子和渗透通量都有提高，并在填充量为１６．７％附近出现极大值。随着料液中乙醇含量的增大，渗透通量减小，分离因子增大；随着料液温度的升高渗透通量显著增大，分离因子则稍有下降。并简单讨论了超细粉末在乙醇／水混合液分离中的作用。     

Carbon–epoxy composites based on fibers coated with nylon 6,6: hygrothermal ageing versus interlaminar shear strength

Carbon fibers were coated in situ with a thin film of polyhexamethylene adipamide by an interfacial polycondensation technique. The modified fibers were used for the preparation of epoxy-based unidirectional composites. Specimens of these materials were immersed in water until equilibrium conditions were attained. The weight gain at equilibrium was determined as a function of the immersion temperature, the fiber volume fraction and the polyamide content deposited on the fibers. Water penetration in specimens made with uncoated carbon fibers increases when the volume fraction decreases. Introduction of the polyamide interlayer initially increases the water absorption, but reduces it at higher immersion temperatures and/or higher polyamide contents. The treated specimens were subjected to the short beam test to determine the interlaminar shear strength (ILSS). The data show that the ILSS decreases with water penetration but increases when the immersion temperature increases from 40 to 70°C. The overall performance encountered is discussed in terms of the possible roles of the polyamide interphase while taking into account mechanisms concerned with matrix plasticization, interphase degradation and residual stress relaxation.     

Reactions of mercury salts with benzo- and tetrafluorobenzobarrelenes

Regiochemistry and stereochemistry of the addition of mercury salts to benzobarrelene and tetrafluorobenzobarrelene have been studied in acetic acid and methanol. The effect of the substrate structure on the regiochemistry of the reaction is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1105–1108, June, 1994.     

Thermoanalytical procedures to identify the morphology of polycrystalline materials

Polypropylenes of differing morphologies were examined by differential thermal analysis. The problems of reordering during the programmed heating are discussed. Four potential procedures by which the reordering could be inhibited are considered, and three of these are experimentally assessed. Their advantages and deficiencies are identified. Two pretreatments, an etching and a crosslinking, are recognised as able to qualitatively characterise the initial morphology, with a preference for the former. A test to identify the occurrence of reordering is identified. In celebration of the 60^th birthday of Dr. Andrew K. Galwey     

高抗冲聚丙烯序列结构的综合表征

用高分辨＾１３Ｃ ＮＭＲ、ＦＴＩＲ等手段获得了高抗冲聚丙烯的组成和序列分布等链结构方面的信息。用ＤＳＣ、ＷＡＸＤ等方法研究了它们的结晶行为、熔融转变及晶体结构，多种方法相结合有效地表征了高抗冲聚丙烯的序列结构。     

交流变频调速技术在二辊轧机压下系统中的应用

介绍一种采用变频调速技术控制的二辊轧机压下系统。该系统可控制轧机压下系统的速度在工艺要求的范围内无级可调，压下量以数字动态显示，控制准确、操作方便。文中对系统的组成及工作原理作了较详细的介绍。     

非均匀有耗媒质部分参数的重建

在高频部分，通过用Ｗｅｎｔｚｅｌ—Ｋｒａｍｅｒｓ—Ｂｒｉｌｌｏｕｉｎ—Ｊｅｆｆｅｒｙｓ（ＷＫＢＪ）解作为内场近似，本文证明了有耗非均匀媒质的反射系数在复平面上的轨迹是个圆。根据不同入射角度、不同极化的高频反射系数圆的圆心与半径，可以重建出有耗媒质的部分关键参数。本文方法同时适用于已知复反射系数谱和仅知反射系数振幅情况。文中给出具体重建实例。     

脉冲激光LGA法钛表面氮化及其XRD和SEM微观分析

用调Ｑ－ＹＡＧ和ＸｅＣｌ脉冲激光在钛表面以激光气体合金化方法生成氮化钛层，用Ｘ射线衍射仪分析了不同激光能量、不同Ｎ２气压不同作用脉冲数等条件下ＴｉＮ的结晶取向、结晶形态、氮化程度，用扫描电镜观察了它们的微观结构，对脉冲激光的ＬＧＡ法机理进行了探讨，也发现了用ＬＧＡ法对Ｍｏ的氮化生成Ｍｏ２Ｎ．     

Trade-off analysis on cost and manufacturing technology of an electronic product: Case study

A trade-off analysis on the cost and system packaging metrics of an electronic product aimed at the commercial/retail industry has been carried out. By comparing the system cost and packaging metrics with those of comparable consumer products, we have determined that there is opportunity for significant cost, size, and weight reduction of the overall electronics packaging system. These include the use of fine pitch IC packages, smaller discrete components, denser PCB wiring technology, double sided IC package surface mount, surface mount connectors, and improved plastics for the product housing. The analysis concluded that PCB area reduction of 40%, using a single PCB instead of three boards, reduction in board cost of over 50% and product weight reduction of over 28% are possible using available technologies.     

加强通信行业管理 促进通信事业的高速 健康发展

本文概要介绍了国家公用通信网的高速发展，这一发展为加强通信行业管理，统筹规划，联合建设，合理组网，为社会，尤其是为各部门的大用户提供服务打下了一定的物质基础。本文还对社会上关心的几个有关政策性问题作了说明。