变速切削系统振动频率的变化特征

本文主要讨论变速切削系统中颤振频率随机床主轴转速变化的规律。理论分析和试验结果都证明在变速切削中颤振频率随转速呈分段线性锯齿状变化。试验在立式铣床和普通车床上进行。     

Electromechanical Conversions in Composite Dielectric Materials During Complex Thermomechanical Excitation

It is shown that the degree of the stress-strain state created by temperature field can be estimated by using the electromechanical conversion phenomenon. It is established that the electromagnetic response to impact excitation of composite materials is a structure-sensitive characteristic.     

关于图形识别的视觉反应的研究

文中叙述了以实验的方法所进行的人工智能视觉领域的基础性某些图形识别的研究工作。在实验中将一些字母和图形按拓扑结构和几何性质分组。试图寻找人类视觉在图形识别过程中的一些规律，运用了模糊数学中的综合评定法。     

基于图象处理的精液自动分析系统

本文阐述了基于图象处理技术的SIA男性精液自动分析系统的基本原理和设计方法。SIA系统采用单帧存实时拼版硬件电路，解决了实时快速获取精子运动轨迹线的技术难点。通过对精子轨迹留和精液静止图象分析，获取精子的活动参数和静态参数。在图象分析中使用了膨胀技术，有效地解决了轨线断裂问题。临床测试表明，SIA系统的检测精度明显高于人工检测的国际误差标准，且同份精液在相同条件下的重复检验结果间无统计学意义。     

Purification and renaturation of recombinant human lymphotoxin (tumour necrosis factor beta) expressed in Escherichia coli as inclusion bodies

High level expression of recombinant human tumour necrosis factor β (rh TNF-β) in Escherichia coli results in the formation of two portions of protein, namely soluble active protein and insoluble protein which is inactive and aggregates in the form of inclusion bodies (IBs). In this study, a procedure for purification and renaturation of rh TNF-β from inclusion bodies has been designed and verified experimentally with a product purity of more than 90% and a recovery of about 30%. The procedure includes washing of IBs with specific wash buffer (Triton X-100/EDTA/lysozyme/PMSF), their solubilization with 8 mol dm^?3 alkaline urea, purification with ion-exchange columns, refolding with renaturation buffer and finally concentration and desalination with an ultrafiltration membrane. The characteristics of the renatured protein were identical with those of purified protein from the soluble fraction as demonstrated by (1) SDS-PAGE, (2) cytotoxic activity on mouse L929 cells, (3) N-terminal amino acid sequence, and (4) gel filtration chromatography.