宽带放大器可靠性问题浅析

叙述了国产高频宽带放大器的质量和可靠性现状，详细介绍了这类产品的质量一致性检验、可靠性摸底试验和现场使用过程中出现的可靠性问题，用统计的方法得出了可靠性特征量，通过对失效样品的失效分析，总结出宽带放大器主要的失效模式和失效机理，并提出了消除和减少失效、提高宽带放大器可靠性的措施和建议。     

智能机理与软计算

随着计算机科学技术,特别是人工智能及其它相关学科的发展,关于人脑智能机理的研究引起越来越多的注意。与此同时、出现了关于软计算的研究.旨在研制出高机器智商系统(High Maehine Intelli-gene。Qt,,:sen:、产tom)[,〕。本文将初步探索智能机理与软计算两者间的关系以及把它们结合起来解决问题的可能性和途径。     

Fastmet工艺评述

介绍了Ｆａｓｔｍｅｔ工艺及发展状况，并对工艺特点和指标进行了分析。使用冷固结含碳球团和转底炉使该工艺可直接采用粉矿和提高生产效率，但因硫含量高、铁品位低而产品质量较差。不过投资和生产成本与传统工艺比较却占有较大优势。     

A Topological Implementation for Motion Planning of a Robotic Arm

An efficient path planning algorithm based on topologic method is presented in this paper.The collision free path planning for three-joint robotic arm consists of three parts:partition of C-space,construction of CN and search for a path in CN.We mainly solved the problems of partitioning the C-space and undging the connectivity between connected blocks,etc.For the motion planning of a robotic arm with a gripper,we developed the concepts of global planning and local planning,and discussed the basic factors for constructing the planning system.In the paper,some evaluation and analysis of the complexity and reliability of the algorithm are given,together with some ideas to improve the efficiency and increase the reliability.At last,some experimental results are pesented to show the efficency and accuracy of the algorithm.     

Nitric oxide reduction and carbon monoxide oxidation over carbon-supported copper-chromium catalysts

Carbon supported copper-chromium catalysts are shown to be very active for both the reduction of nitric oxide with carbon monoxide and the oxidation of carbon monoxide with oxygen. Mixed copper-chromium oxide active phases have good activity in the simultaneous removal of nitric oxide and carbon monoxide from exhaust gases. The influence of several catalyst variables has been investigated. The activity per volume of catalyst increases with increasing loading, while the intrinsic activity shows a maximum around C/M=100−50. An optimum catalyst for nitric oxide reduction and carbon monoxide oxidation has a copper/chromium ratio of 2/1. The apparent activation energy for the carbon monoxide oxidation over carbon supported copper-chromium catalysts is 77 kJ/mol, suggesting that the Cu---O bond rupture is the rate-limiting process. The reduction of nitric oxide takes place at higher temperatures. Since all catalysts have a low selectivity for molecular nitrogen formation at lower temperatures, the dissociation of nitric oxide is probably rate determining, resulting in a slightly reduced catalyst system. In an excess of carbon monoxide the reaction is first-order in nitric oxide and zero-order in carbon monoxide. Moisture inhibits the reaction by reversible competitive adsorption, whereas carbon dioxide does not. Oxygen completely inhibits the reduction of nitric oxide due to the more rapid reoxidation of the catalytic sites compared to nitric oxide. Therefore, the reduction of nitric oxide takes place only when all oxygen has been converted and, hence, is shifted to higher temperatures. As a possible consequence, the production of nitrous oxide is reduced. Nitric oxide and molecular oxygen react preferentially with carbon monoxide, so, in an excess of oxidizing component, gasification of the carbon support occurs at higher temperatures after carbon monoxide has been completely consumed.     

醇镁还原法一步制取对氯苯胺的研究

醇镁还原法一步制取对氯苯胺是一种新的方法 ,研究发现最佳反应温度为 80℃～ 85℃ ,反应时间为4h ,对氯硝基苯与镁粉的用量 (物质的量比 )为 1∶3,产率为 80 %。     

三峡水库减淤增容调度方式研究——多汛限水位调度方案

本文建议在汛期中小流量时（Q<35000m3/s），将坝前水位维持在148～151m；出现汛情且流量更较大后，将坝前水位降低到143m；入库流量大于35000m3/s且短期预报将出现大于十年一遇洪水时，预泄洪水到135m.按这一调度，汛期约80％时间可以维持在较高水位，一般洪水期。汛限水位143m不影响坝区通航，135m水位迎洪可大量增加防洪库客。到100年后可减淤30亿m3，增加防洪库容约40亿m3.变动回水区减淤40%，优化了坝区水沙搭配，可改善通航条件。降低库区洪水位，缓解防洪与移民的矛盾。可对发电带来较大好处：提高发电效益，减少粗沙过机。初期水库排沙比大于原方案，可减轻下游冲刷。同时，可减小三峡汛初泄水与鄱阳湖防洪的矛盾。     

水溶性防氧化剂在SMT用印制板上的应用

水溶性的防氧化剂是一种有机可焊性保护剂。其方法是在印制板完全阻焊、字符层的印刷，并经电检之后，通过表面浸渍在裸铜的贴片位或通孔内形成一种耐热性的有机可焊性膜层。这种有机、可焊、耐热的膜层，膜厚可达0.3-0.5mm，其分解的温度可达约300℃，传统的印制板的热风整平法亦无法满足QFP愈来愈密集的需求，同时也无法满足SMD表面平整度的要求，更无法适应PCB薄型化生产。烷基苯并咪唑的OSP法能弥补这项缺陷，因而在PCB业乃至SMT产业中得到了广泛的应用。     

控制棒驱动机构常温通风均匀性试验研究（续篇）

本文叙述控制棒驱动机构在常温通风均匀性方面的试验。通过平顶型堆顶结构和球面型堆顶结构通风均匀性试验的比较,找出通风的阻力、风速和不均匀系数间的规律。     

7-羟基全氢化噁唑并噁嗪鞣剂的合成及其鞣性研究

报导了新型鞣剂 7-羟基全氢化唑并嗪 (以下简称 OX- Z)的合成方法。试验确定合成的最佳条件为 :在氮气保护下 ,将等摩尔量的二乙醇胺在 10℃水浴中缓慢滴入乙二醛中 ,滴加时间 0 .5 h,在 2 0℃水浴中继续反应 1.5 h,产率为 6 2 .9%。 OX- Z对浸酸绵羊皮单独鞣制 ,可使收缩温度升高到 87℃。最佳鞣制条件为 :p H10 .0 ,OX- Z用量 5 % ,鞣制时间 8h。在对 OX- Z与皮胶原的结合类型的研究中证明它们之间是以化学键结合的。