Structure of contact Lie algebras related to locally-finite derivations

In this paper, we determine the isomorphism classes of contact simple Lie algebras constructed from locally-finite commuting derivations, introduced earlier by the second author. These algebras are in general not finitely graded.Supported by NSF grant 10171064 of China and two grants ``Excellent Young Teacher Program' and ``Trans-Century Training Programme Foundation for the Talents' from Ministry of Education of China Mathematical Subject Classification (2000):Primary 17B65; Secondary 58F05     

飞艇升空过程超压控制可视化仿真

基于Vega与Creator平台研究了飞艇升空过程中飞艇超压控制的三维可视化仿真技术,建立了飞艇升空过程的数学模型与适合研究飞艇升空过程中超压控制的大气模型,并在Creator平台上开发了飞艇的实体模型.基于所建立的数学模型和实体模型,在VC6.0环境下完成了飞艇升空过程超压控制可视化仿真系统,给出了可视化的仿真结果.通过仿真试验分析,结果表明数学模型可行,在设置的超压控制策略下飞艇对环境有一定的自适应能力,能够比较平稳地升到所设定的高度.     

Distributed Dynamic Navigation for Sensor Networks

Navigation with sensor networks has shown many advantages and great potential in many scenarios.Previous works have mainly focused on selecting the shortest path to navigate an internal user out of an emergency field.However,they did not consider variations of the dangerous areas which usually occur in practical applications.This paper presents an efficient dynamic routing algorithm to successfully guide users to the destination exit.The navigation goal is looking for a safe and short path to enable the user to escape from a dangerous area as fast as possible.Without knowing the locations of the nodes,the user is guided by a sequence of sensor nodes to pass through the dangerous areas.The algorithm ensures the navigation path security by predicting the dynamic changes affecting the navigation path.The performance of this approach is evaluated using extensive simulations to validate its effectiveness.Simulations show that the approach is scalable and performs well in various settings.     

Synthesis of low grafting density molecular brush from a poly(N‐alkyl urea peptoid) backbone

The synthesis of a molecular brush was accomplished by combining step‐growth polymerization and reversible addition fragmentation chain transfer (RAFT) polymerization in a “grafting from” methodology. A symmetrical N‐alkyl urea peptoid sixmer containing alkyne functional groups was prepared using a divergent strategy, and the structure of the product was confirmed using NMR spectroscopy and mass spectrometry. A step‐growth process was used to prepare a linear poly(N‐alkyl urea peptoid) by reacting the diamine‐functionalized N‐alkyl urea peptoid sixmer with a diisocyanate. RAFT chain transfer agents were coupled to the poly(N‐alkyl urea peptoid) backbone through a copper‐catalyzed azide/alkyne cycloaddition reaction. The afforded macro‐RAFT agent was used to sequentially polymerize styrene and tert‐butyl acrylate block copolymer arms from the poly(N‐alkyl urea peptoid) backbone. The tert‐butyl groups were removed using dilute trifluoroacetic acid affording hydrophilic polyacrylic acid segments. The molecular brushes were observed to generate micelles in aqueous solution. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis and characterization of well‐defined lactic acid–PEG cooligomers and its tricarbonyl rhenium conjugates

This article describes the synthesis and characterization of hydroxyl tailored, molecularly defined biodegradable cooligomers capable of chelating rhenium for potential radiopharmaceuticals. New insights were gained during the synthesis of lactide based on dimethylaminopyridine‐catalyzed transesterification. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

数学课堂教学中培养学生自学能力的尝试

本文介绍了在中师数学课堂教学中培养学生自学能力、减轻学生的课业负担、提高课堂教学效率方面所做的探索性尝试。     

Spline wavelet in the resolution of overlapping voltammetric peaks

Spline wavelet transform is used to resolve overlapping voltammetric peaks. A suitable resolving factor is chosen to multiply the filters of spline wavelet and make it a peak resoluter. Simulated overlapping voltammetric peaks are processed by the peak resoluter and satisfactory results are obtained. Base-line separation can be achieved, the relative errors of peak position are less than 3.0%, and the relative errors of peak area are less than 5.0%. The effect of different resolving factors and spline wavelet basis are discussed. To test the procedure, two systems, cadmium (Ⅱ)-indium (Ⅲ) and lead (Ⅱ)-thallium (Ⅰ), are used.     

线路方案比选多目标决策分析

本文通过对线路方案比选的多目标决策分析，建立了线路方案比选的 ＴＯＰＳＩＳ模型，对线路方案非劣解集进行排序，提供方案的优先顺序．     

Relation between sers intensity and electronic structures for a series of compounds C6H5(CH2)n COOH (n = 0, 1, 2)

In this paper, the SERS spectra of a series of compounds C₆H₅(CH₂)_nCOOH (n = 0, 1, 2) adsorbed on colloidal silver are recorded and compared with each other. The relation between the SERS intensities and the electronic structures of the compounds are discussed. The results support the molecular enhancement mechanism on SERS, especially the charge transfer idea.     

积极心理学及其在课堂教学中的应用

积极心理学是美国心理学界兴起的一个新的研究领域。它是利用心理学目前已比较完善和有效的实验方法与测量手段,来研究人类的力量和美德等积极方面的一个心理学思潮。从当前的发展态势来看,积极心理学不仅仅在心理学领域里取得了巨大的成就,而且其思想已经渗透进了心理治疗、教育、社会学、管理学和经济学等多个社会领域。本文主要关注积极心理学对课堂教学的积极作用,即积极心理学可以帮助学生培养积极情绪、解决教师的职业倦怠问题和建立良好的师生关系。