Chinese Wall策略及其在多级安全中的扩展

Chinese Wall安全策略因不同于BLP的动态特性而备受人们关注，但Brewer和Nash定义的Chinese Wall策略只适用一定的应用范围， 没有考虑普遍存在的多级访问控制的限制条件。本文主要结合多级安全环境，分析研究具有多级访问控制环境的Chinese Wall策略的扩展实现。根据该环境中的Chinese Wall的利益冲突处理表现为数据聚合问题，利用数据标签的格级标定，提出一种基于历史访问库和利益冲突聚合链表的安全策略实现方法。     

Reproductive Biology and Prospects for Conservation of Caldesia parnassifolia (Alismataceae)——A Threatened Monocot in China

Caldesia parnassifolia (Bassi ex Linn.) Parl. in China has declined in number in recent years and is increasingly faced with the risk of extirpation arising from anthropogenic changes associated with rapid urbanization and expansion of both agriculture and infrastructure. To aid in provision of the data needed for effective conservation of the species, studies on the habitat, pollination ecology, and breeding system of C.parnassifolia were carried out on natural populations occurring in Southeastern China. Flowering in the study populations extended for more than eighty days beginning in early summer. Floral anthesis occurred in the morning hours and proceeded rapidly, lasting about 45 min. Flowers lasted ca.8h. Caldesia parnassifolia is self-compatible; however autogamy resulted in lower seed set than geitonogamy and xenogamy as well as free pollination. The data on pollen/ovule (P:O) ratio is consistent with a partially selfing and outcrossing mating system. Interpopulational crosses yielded similar seed set to within-population crosses. Agamospermy did not occur in the study populations. Propagation is achieved through seeds as well as through turions which commonly occur in the inflorescences. Flies (Insecta; Diptera) were the most frequent visitors to the flowers of C.parnassifolia; however bees (Insecta;Hymenoptera )composed a larger proportion of effective pollinators. The Syrphidae species Sphaerophoria indiana (Bigot) presents evidence of oligolectic foraging behavior. Recommendations are made on the immediate steps necessary for conservation of Caldesia species in China.     

油位液面自动控制系统

一般电子技术刊物中介绍《水位自动控制》的电路较多，由于油的易燃性，其控制电路中的采样部分较难设计，现虽有各类高，中档传感器面市，但价格都非常昂贵。根据压力传动原理设计出的一款经济，实用，安全的油位控制电路，可对一般贮油装置中的油位进行自动控制。     

变性剂和巯基修饰对黄精凝集素Ⅱ构象和活性的影响

采用圆二色谱、荧光光谱，研究了黄精凝集素Ⅱ（Polygonatum cyrtonema Hua.LectinⅡ,PCLⅡ）在4mol/L和6mol/L盐酸胍中，以及巯基修饰后，其活性和分子构象的变化关系，研究结果表明：PCL Ⅱ是一种稳定的蛋白质，巯基剂虽不影响其活性，但可使其分子构象发生变化，去除修饰剂后其结构部分能够恢复。在4mol/L盐酸胍中，PCL Ⅱ活性及构象可发生很大变化，去除盐酸胍后其活性恢复；6mol/L盐酸胍中，呈现典型的无规卷曲构象，活性完全丧失，去除盐酸胍后活性仍不能恢复，表明活性中心已遭到不可逆的破坏。     

乳状液膜法提取和浓缩氨基酸的研究

本以TOMAC为载体，ECA4360J为表面活性剂，用内外相离子浓度梯度为推动力研究了L－天冬氨酸在乳状液膜体系里的传输，对各种因素的影响进行了系统的研究，确定了此体系的最佳膜相组成和实验条件。减少了溶胀和膜破裂等不利因素对提取结果的影响。实现了L－天冬氨酸的提取和浓缩。     

Rapid Amplification of 5‘ cDNA End of S.Liaotungensis Choline Monooxygenase Using Inverse PCR RACE

Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase the author successfully cloned the 5‘ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5‘-phosphated RT primer and two pairs of specific inverse PCR primers.Compared with the anchored PCR RACE,inverse PCR RACE has bettter specificity and higher amplification.     

棉花密度试验总结

在棉花高产栽培模式方面，选用适宜品种，着眼于提高密度以达到高产、优质、高效的目的，针对六种栽培模式密度的对比，找出适合本地的棉花高产栽培模式及密度。     

NMR Study of Hydroxyl-Substituted Macrocyclic Hexaamine in Solution

The NMR methods (including ^1H NMR, variable temperature method and the 2D COSY technique) were employed to study the conformation of 3,13-dihydroxyl-1,5,8,11,15,18-hexaazacyclicamine hexahydrobromide in aqueous solution. It was found that the ring is flexible.     

我国高新技术开发区发展的关键要素和战略目标

我国高新技术开发区发展的关键要素和战略目标杨冰行，徐鹤荣，肖元真一、高新技术开发区发展的关键要素高新技术产业开发区的发展，不但推动了高新技术成果商品化，促进了对传统产业的改造，而且为深化改革提供了有益的启示。为不失时机地加快我国高新技术产业开发区的发...