Introduction and overview. Statistical methods in genetic epidemiology

Common terms used in genetics with multiple meanings are explained and a brief overview given of the four major areas of genetic epidemiology--the study of familial aggregation, segregation, cosegregation and association. Familial aggregation measures the potential for a trait to have a genetic aetiology. Segregation analysis uncovers single gene segregation. Cosegregation with genetic markers gives rise to linkage, which is used to locate trait genes on the genome. Association analysis is used for fine mapping, but rests on the assumption that linkage disequilibrium exists.     

Vamac(R)乙烯丙烯酸酯三元共聚物系列专题讲座(二)Vamac(R)牌号及其性能

该文介绍了Vamac(R)各牌号产品的性能特点及典型配方的性能,有助于工程技术人员的对比选用和分析.     

清管与检测技术综述

介绍了各种清管器的原理以及清管目的,不同清管器的结构及其功能,并且简单介绍了清管作业系统。对清管技术的深化技术研究——漏磁检测、超声波检测以及多通道涡流检测原理进行了介绍。阐述了国内外在清管器研究与应用方面的研究进展,指出了当前清管器存在的问题和研究方向。     

Vamac(R)乙烯丙烯酸酯三元共聚物系列专题讲座(一)Vamac(R)聚合物及其性能概述

该文阐述了Vamac(R)聚合物性能特征及组成,概述了Vamac(R)聚合物的耐热老化、耐介质、耐燃、耐低温、耐压缩、耐候、耐屈挠等方面的性能.此外还介绍了Vamac(R)各牌号产品的性能特点及典型配方的性能.     

全球头发定型剂和固定剂纵览

对过去4年的头发定型剂和固定剂的发展情况作了综述,讨论了各公司的定型剂和固定剂品牌的概况,市场对定型剂和固定剂产品的需求不断增长.进一步讨论了定型剂和固定剂配方中所使用的聚合物和流变改性剂的发展情况.不断研发出许多新的聚合物和流变改性剂,推动了定型剂和固定剂市场向前发展.     

仰角式油水分离器概述

对于大多数高含水率油田研发的仰角式游离水脱除器,具有处理量大、结构简单和分离效率高等优点。介绍了仰角式游离水脱除器的结构,分离原理,分离效率,总结出仰角式油水脱除器的优点,仰角式分离器处理效率高,脱除效果好,单位处理量造价低,主要适用于含水90%以上的油井采出液。     

An overview of degradable and biodegradable polyolefins

The use of engineering plastics, especially polyolefins has increased significantly in recent decades largely due to their low cost, good mechanical properties and light weight. However, this increase in usage has also created many challenges associated with disposal and their impact on the environment. This is because polyolefins do not easily degrade in the natural environment and hence the need for degradable polyolefins has become a major topic of research. Degradable polyolefins are designed to retain functionality as a commodity plastic for the required service life but degrade to non-toxic end products in a disposal environment. They are typically designed to oxo-degrade while undergoing changes in chemical structure as a result of oxidation in air, thus causing the breakdown of the molecules into small fragments that are then bioassimilated. This article presents (i) a comprehensive review of the chemistry of additives for the degradation of polyolefins, (ii) a patent and scientific literature summary of technologies including commercially available systems, (iii) the mechanisms of degradation and biodegradation, (iv) testing methods and (v) toxicity.     

Imidazoline and its derivatives: an overview

Imidazoline derivatives, a class of novel cationic surfactants are presently gaining importance in global detergent market due to their wide range of applications. These are extensively used mainly as fabric softeners and antistatic agents. The present communication reviews the preparation, reaction scheme, reaction rates and properties of imidazoline derivatives. The analysis of imidazoline derivatives, its mode of action, their biodegradation and various applications have also been discussed.     

聚乳酸市场概况及技术发展

介绍了目前世界、我国的聚乳酸的生产概况、聚乳酸产品的应用领域以及聚乳酸生产技术发展的情况,并对我国聚乳酸产业的发展进行了分析与展望。聚乳酸的高生产成本,限制了其大批量的生产使用,今后需要从国家产业政策扶持、进一步优化生产工艺,简化和缩短工艺流程,降低原料消耗,从而降低PLA产品价格,实现塑料产业革命。