局部网实时通信协议RTHP

提出一个适合于实时通信的局部网协议ＲＴＨＰ。其主要特点是保留／调度过程与数据传输并行地进行，另一个有趣的特点是它将报文期限、报文优先级和一个分布中断机构合起来，从而在负载较重的情况下能改善实时信息的传输性能．文中还通过模拟模型评价了该协议的性能，并且分别与标准令牌环和ＳＫＩＰＮＥＴ网进行了比较。     

对逆变器进行脉宽调制的面积等值算法

本文叙述了对逆变器进行脉宽调制的新算法——面积等值算法的基本原理;对逆变器输出波形进行了谐波分析;给出了用TP 801单板机实现该算法的硬软件结构以及实验结果。     

Influence of diet on plasma tryptophan and brain serotonin levels in mice

Groups of mice were maintained for up to 78 weeks on tryptophan restricted, protein restricted and control diets. Plasma tryptophan levels were significantly reduced by both forms of dietary restriction. Brain serotonin levels were significantly reduced only in mice on the tryptophan restricted diet, but not for mice on the protein restricted diet. The protein-restricted diet contains less of the large neutral amino acids which compete with tryptophan to enter the brain. It is known that protein restriction and tryptophan restriction extend lifespan. The results presented here suggest that extension of lifespan and lowering of brain serotonin are not related.     

藏药异叶青兰的黄酮成分

作者从藏医药异叶青兰中分离得到两种黄酮类化合物和一种无机物，根据化学反应及光谱分析，并与已知化合物比较，可认定三种化合物为：产物Ｉ为含有３－０－糖甙结构单元的二氢黄酮醇，产物Ⅱ是含有３－０－糖甙结构单元的黄酮醇，产物Ⅲ为氯化钾。     

Molecular and genetic damage in humans from environmental pollution in Poland.

Extreme environmental pollution such as that found in the highly industrialized Silesian region of Poland has been associated with increased risk of cancer and adverse reproductive outcomes. Among the most prevalent carcinogenic and mutagenic air pollutants in Silesia are the polycyclic aromatic hydrocarbons (PAH) which are largely produced by industrial and residential combustion of coal. Molecular epidemiology aims to prevent disease by using biological markers to identify risks well before clinical onset to allow effective intervention. Here, we use a battery of biological markers to measure molecular and genetic damage in peripheral blood samples from residents of Silesia and from persons living in a rural, less polluted area of Poland. The results show that their exposure to environmental pollution is associated with significant increases in carcinogen-DNA adducts (PAH-DNA and aromatic adducts), in sister chromatid exchange including high-frequency cells, and in chromosomal aberrations as well as a doubling in the frequency of ras oncogene overexpression. We found that aromatic adducts on DNA were significantly correlated with chromosomal mutation, providing us with a molecular link between environmental exposure and a genetic alteration relevant to cancer and reproductive risk.     

Odour preference of a parasitic wasp depends on order of learning

FemaleLeptopilina boulardi wasps, larval parasites ofDrosophila melanogaster, can learn to respond to more than one odour by associating these odours with oviposition experience. These wasps can memorise and respond to at least two different odours, and prefer the last one learnt.     

单片机在胶粘鞋配底烘干自动装置及成鞋自动流水线上的应用

本文利用单片微机对87201339及902141392专利技术的控制系统进行了成功的改造.本文阐述了硬件系统的组成及工作原理,并提出了一种简易的交流伺服系统的组成及控制模型。制鞋机的数控化使得制鞋工艺得到优化,各类工艺参数得以实现,制鞋质量得到提高。     

Least squares algorithms for constructing constrained ultrametric and additive tree representations of symmetric proximity data

A mathematical programming algorithm is developed for fitting ultrametric or additive trees to proximity data where external constraints are imposed on the topology of the tree. The two procedures minimize a least squares loss function. The method is illustrated on both synthetic and real data. A constrained ultrametric tree analysis was performed on similarities between 32 subjects based on preferences for ten odors, while a constrained additive tree analysis was carried out on some proximity data between kinship terms. Finally, some extensions of the methodology to other tree fitting procedures are mentioned.The first author is supported as Bevoegdverklaard Navorser of the Belgian Nationaal Fonds voor Wetenschappelijk Onderzoek.     

关于最大亏格达到下界的三连通三正则简单图

已被证明二连通三正则简单图的最大亏格至少为其圈秩的三分之一。且，当节点数可被三整除时，这个下界可以达到。本文提供了达到最大亏格下界的三连通三正则简单图所具有特殊结构，这就是三角形因子。     

甜菜上一种球状病毒分离物的特性研究

由田间自然感病和甜菜黑色焦枯病株，坏死黄脉型病株及无明显症 甜菜上分离到一种球状病毒，病毒呈二十面体，直径约25nm，有空心和实心2种粒子，具有分子量为24．7kd的外壳蛋白和长度分别为3．8kb,1.4kb,1.1kb的3个双链RNA组分，该病毒具有较强的稳定性和侵染性，蚜虫不能传毒，土壤诱发可传播，易通过汁液摩擦接种侵染多种植物；但回接甜菜只偶尔出现个别褪绿斑或不规则褪绿斑，并不表现田间症状，表明该病毒与甜菜黑色焦枯病等病害无直接关系。