Joint Strength with Soldering of Al2O3 Ceramics After Ni-P Chemical Plating

Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at temperatures below 70~C. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.     

关于2-群的注记

通过对2-群的研究，得到了一类2-群的结构，进而给出了一类无限2-群有无限的阿贝尔子群的例子．     

2,3-二溴甲基-5,6-二氰基吡嗪的合成新方法

以2,3-二甲基-5,6-二氰基吡嗪为原料,在AIBN的引发下,用NBS进行自由基溴化反应,合成了标题产物,其结构经熔点,MS,1HNMR,UV等予以确证,从而为该物质的合成探索了一条新途径.     

数列{N(u,v)=2uv+u+v}的若干性质

本文得出了数列{N（u,v)=2uv u v}的一些性质，并提出了关于素数的一个猜想。     

硫酸钛水解制备TiO2纳米粒子载荷添加剂

以硫酸钛为前驱体，采用溶胶－凝胶－超临界干燥法制备TiO2纳米粒子润滑油载荷添加剂。采用红外光谱、BET氮容量吸附、透射电镜、热生－差热分析、X－射线衍射等手段对TiO2纳米粒子的特性进行了表征，分析了制备过程中的各种影响因素。结果表明，采用强烈搅拌、匀速滴加絮凝剂、控制反应终点的pH值以及用乙醇为介质进行超临界干燥的方法制备出的TiO2纳米粒子的平均粒径为15－20nm，比表面积约为100m%2/g，其结构为锐态型，表面有微量水和乙醇吸附。     

Turbo码译码深度δ对其译码性能的影响

介绍了两种新的译码算法：AL－1和AL－2，通过计算机仿真结果，讨论了该算法的译码深度对Turbo码性能的影响。     

锡原子多重线5p6s—5p~2分析

本文分析ＳｎＩ共振谱线组，线性拟合计算基态和第一激发态的谱项参数．增加校正项─ａＬ（Ｌ＋１）和ａＪ（Ｊ＋１），大大改善拟会精度     

实时实现MPEG2运动估计的DSP处理系统

本文根据ＭＰＥＧ２的图像标准与要求，利用若干大规模集成电路芯片，设计了实时实现活动图像运动估计的ＤＳＰ处理系统板，通过序列图像的测试，证明其工作正常，性能可靠，完全符合ＭＰＥＧ２的技术规范，从而为我国近期实现ＭＰＥＧ２的编解码系统、乃至ＨＤＴＶ实验系统在硬件方面打下了良好的基础。