一种实用的二次群多点会议电视系统

本文介绍总线式会议电视联网方案在二次群速率(8.448Mb/s)彩色数字会议电视上的实现方法,以及一种实用的多点会议电视系统.并对具体实现的关键问题作了较详细的讨论。     

GPS技术用于高等级公路勘测的若干问题

介绍了近年来全球定位系统技术用于线路控制测得的具体做法，结合在若干条高等公路上的应用实例，分析研究了应引起注意的若干问题。实证明，在高等级公路勘测中采用ＧＰＳ技术，将从根本上改进勘测技术，更好地为线路设计和施工放线服务。     

城市GPS控制网的分级布设

为了满足城市建设和发展的需要，提出了应用全球定位系统（ＧＰＳ）技术分级布设城市控制网的方法和相应的数据处理手段，通过对实例的计算，充分说明了大中城市中ＧＰＳ控制网分级布设的优越性和必要性；同时，还探讨了分级布网对点位精度的影响，通过对不同布网方案的比较，分析，得出分级布网不但能保证全网的精度均匀，一致性，而且能地改善点位精度，特别是当首级网布设均匀，合理时，效果尤其显著，因此，建议在今后的大中城市     

pH测量与控制技术新进展

分析了ｐＨ值测量与控制技术的新进展，介绍了几种新型的ｐＨ测控技术的基本原理及应用。     

G-G PATTERNING METHOD OF SILK WEAVING IN EARLIER CHINA

There are some unique techniques in the Chinese traditional silk production. 2-2 patterning method is such one suggested by foreign scholars. But this paper gives a more extensive concept, G-G method, which includes the 2-2 method after studying more fabrics from the Shang. to the Five Dynasties. Finally, the paper discusses the truth of G-G method the (?) applied in, and some characteristics of G-G method.     

评岛尾永康的《中国化学史》

文章对于日本学者撰写的第一部《中国化学史》进行了分析评论，认为该书具有的主要特点是：（１）时代性，概括了直到１９９２年以前的最新研究成果；（２）严谨性，运用文献丰富，以求得出严密结论；（３）辩驳性，注意从不同见解的争论中进行阐述，自然得出结论；（４）社会性，注意把化学发展置于整个社会中考察，揭示深层动因；（５）比较性，注意把中国化学发展置于世界范围考察，体现中国的特点和作用；（６）形象性，运用相当丰富的图片进行叙述，具体、生动；（７）日本视野性，以日本学者特有的角度阐述中国化学发展，具有独到之处。文章还指出了该书一些需要改进和提高之处。     

-S控制图的多功能程序系统

本文讨论了—S控制图的统计原理及其多功能程序系统.介绍了该程序系统的结构、功能、程序主框图和使用特点,并提供了一个应用实例。     

寻求"自我"生成的历史基点--20世纪末女性历史写作的形态学分析

20世纪末女性写作以其鲜明的个体话语方式通过与历史对话,探求女性"自我"生成的基点,揭穿隐蔽在现实背后的历史诡计.女性历史写作的多形态存在,确立了女性写作者与历史对话的信心.     

Sex-peptides: seminal peptides of the <Emphasis Type="Italic">Drosophila</Emphasis> male

Mating affects the reproductive behaviour of insect females: the egg-laying rate increases and courting males are rejected. These post-mating responses are induced mainly by seminal fluid. In Drosophila melanogaster, males transfer two peptides (sex-peptides, = Sps) that reduce receptivity and elicit increased egg laying in their mating partners. Similarities in the open reading frames of the genes suggest that they have arisen by gene duplication. In females, Sps bind to specific sites in the central and peripheral nervous system, and to the genital tract. The binding proteins of the nervous system and genital tract are membrane proteins, but they differ molecularly. The former protein is proposed to be a receptor located at the top of a signalling cascade leading to the two post-mating responses, whereas the latter is a carrier protein moving Sps from the genital tract into the haemolymph. Sps bind to sperm. Together with sperm they are responsible for the persistence of the two post-mating responses. But Sps are the molecular basis of the sperm effect; sperm is merely the carrier.Received 10 February 2003; received after revision 25 April 2003; accepted 1 May 2003This article is dedicated to the 85th birthday of the discover of the sex-peptide, Prof. Dr. Pei Shen Chen, Zoological Institute, University of Zürich, Switzerland. P. S. Chen has served on the Editorial Board of Experientia (now CMLS) from 1974 to 1988.