Molecular dynamics study on the structure I helium hydrate

A 368- water molecule structure I gas hydrate, encased by the number of helium (He) molecules ranging from two to twenty-two, are calculated by molecular dynamical simulations. The potential TIP4P (transferable intermolecular potentical with four sites) is used for water interactions and Lennard-Jones for He-He and He-water interactions. He molecules do not affect the water lattice and can stabilize the hydrate when their concentration is small. A trough signature of He encased is found at 80～90 meV in the phonon density of states. He molecules prefer to be more off-center in 51262 cages. Heavier isotope He are energetically favorable to be filled in cages.     

水－仲丁醇－碳4三元体系8MPa时的液液平衡

在国内首次建立的一套温度高达３５０℃，压力直至２０ＭＰａ的高压液液相平衡测定装置上，测定了水－仲丁醇－碳４三元体系在８ＭＰａ和４０３．１５，４２３．１５，４４３．１５Ｋ时液液相平衡数据。采用修改的Ｒ－Ｋ方程对此数据进行了理论关联。关联结果与实验数据一致。     

基于推广卡尔曼滤波的多站被动式融合跟踪

将推广卡尔曼滤波(EKF)算法与集中式融合跟踪算法相结合，用于被动式多站跟踪，给出了基于EKF的被动式多站集中式融合跟踪算法。该算法可解决被动式跟踪系统的可观测性及非线性问题。以三个站进行跟踪为例，进行了仿真研究，结果表明该算法具有满意的跟踪性能。     

模糊综合评价防空指挥自动化系统效能

通过对防空指挥自动化系统性能的全面分析 ,建立了其系统效能综合评判的指标体系 ,给出了系统效能评价模型和评价方法 ,介绍了运用择优比较法确定权重的方法 ,并进行了实例分析 .     

高师院校学生数学学习模式研究

本文通过对调查结果的分析,研究了高师院校数学学习模式的现状,提出改进学习模式的若 干建议。     

基于改进等分节点法的启发式布局算法

针对集成电路标准单元模式的布局问题，提出了一个全新的基于改进等分节点法的启发式标准单元布局算法(TETP)，该算法在优化布局过程中采用改进的等分节点法寻找单元目标位置，同时结合局部寻优的启发式算法，对MCNC(Microelectronics Centre of North-Carolina)标准单元测试电路进行实验。结果表明，与布局工具Timber Wolf7．0和FengShui相比，电路布局的总线长度分别平均减少了16％和17％。     

Discovering Frequent Subtrees from XML Data Using Neural Networks

By rapid progress of network and storage technologies, a huge amount of electronic data such as Web pages and XML has been available on Internet. In this paper, we study a data-mining problem of discovering frequent ordered sub-trees in a large collection of XML data, where both of the patterns and the data are modeled by labeled ordered trees. We present an efficient algorithm of Ordered Subtree Miner （OSTMiner） based on two- layer neural networks with Hebb rule, that computes all ordered sub-trees appearing in a collection of XML trees with frequent above a user-specified threshold using a special structure EM-tree. In this algo- rithm, EM-tree is used as an extended merging tree to supply scheme information for efficient pruning and mining frequent sub-trees. Experiments results showed that OSTMiner has good response time and scales well.     

利用形成性评价,促进青年教师成长

本文阐述了形成性评价的概念及特征,对青年教师进行形成性评价的基本理念、基本功能、具体方法及应注意的问题,以便合理有效地运用形成性评价促进青年教师健康发展.     

螺恶嗪化合物在有机溶液中的酸致变色研究

合成了四种螺恶嗪光致变色化合物,并对它们在有机溶剂中所表现的酸致变色现象进行了研究。发现它们与盐酸在室温下形成的复合物(SP.HCl),随溶液极性的增加,其吸光强度增大,吸收光谱发生蓝移。