Reduction mechanism of tioglycolic acid on keratin fibers using microspectrophotometry and FT-Raman spectroscopy

In order to investigate the reduction mechanism of thioglycolic acid (TG) on the keratin fibers, cross-sectional samples of white human hair treated with TG were prepared. The heterogeneous reaction between TG and keratin fibers involving the diffusion of TG into human hair was analyzed at the molecular level using microspectrophotometry and FT-Raman spectroscopy. The diffusion of TG into human hair clearly increased by increasing the treatment time and by raising pH. The TG relative concentration and the disconnected relative concentration of disulfide (–SS–) groups at various depths of the hair samples with pH 9.0 were in good agreement, indicating that the reaction rate (the disconnection of –SS– groups) was faster than the diffusion rate of TG into human hair. From these experiments, we demonstrated that TG diffuses gradually beyond the cuticle region, and toward the inside of the cortex region along with the disconnection of –SS– groups.     

一种新的网络对象存储设备研究

Internet的飞速发展对于存储系统的可扩展性提出了很高的要求,也带来了由数据模型与存储模型的不一致问题引起的服务器性能瓶颈现象.针对这些情况,本文提出了网络对象附属存储设备(NAOSD)的概念,其利用设备处理器的能力直接支持结构化数据存储.这一设计减少了存储系统中数据服务器的负载,增加了系统吞吐量.同时,研究了该设备原型在集群环境中的应用,提出了数据/元数据统一存储与查询式数据定位机制.分析表明,这些机制能够较显著地提高系统扩展性——数据访问时间随系统规模的扩大呈对数增长,优于传统的映射定位机制.我们已经模拟实现了NAOSD,并在性能比较测试中取得了较好的效果.     

用于高频谐振器的PbTiO_3基压电陶瓷

传统的PZT压电陶瓷的相对介电常数较大,一般为1 000以上,用于高频谐振器不易与线路匹配;而PbTiO3基压电陶瓷的相对介电常数较小,一般仅为200左右,对于10 MHz以上频率的谐振器,用PbTiO3基压电陶瓷作为压电振子是最佳的选择。本文主要研究用于高频谐振器的MnO2和Nd2O3改性PbTiO3基压电陶瓷的性质。PbTiO3基压电陶瓷的性质的改善是与此种陶瓷的制备工艺,显微结构和电导机制紧密相关的。     

Investigation into polishing process of CVD diamond films

A new technique used for polishing chemical vapor deposition (CVD) diamond films has been investigated, by which rough polishing of the CVD diamond films can be achieved efficiently. A CVD diamond film is coated with a thin layer of electrically conductive material in advance, and then electro-discharge machining (EDM) is used to machine the coated surface. As a result, peaks on the surface of the diamond film are removed rapidly. During machining, graphitization of diamond enables the EDM process to continue. The single pulse discharge shows that the material of the coated layer evidently affects removal behavior of the CVD diamond films. Compared with the machining of ordinary metal materials, the process of EDM CVD diamond films possesses a quite different characteristic. The removal mechanism of the CVD diamond films is discussed.     

微米／纳米技术及其应用

介绍了当前国际上关于微米、纳米技术及其在微型机械、微型机械电子系统以及在专用集成型仪器等方面的应用。     

Formation and growth mechanism of TiC crystal in TiC_p/Ti composites

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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。     

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。