The measurement of subcritical electroconvection

Under idealized conditions, electroconvection in a nematic liquid crystal sets in at a well-defined threshold of the driving ac voltage. Fluctuating convection rolls of a small amplitude below that threshold have been observed recently. The measurement of the amplitude of these fluctuations is described in detail in this paper. It is based on averaging the light intensity signals using the structure function and a quantitative analysis of the light deflection.     

在体育与健康课教学中培养学生创新能力的途径及方法

培养学生创新能力是体育与健康课教学融入教育改革的需要 ,依据创新学习的基本理论、学习模式及课堂特点 ,体育创新能力培养途径是 :培养体育创新的态度、培养体育创新的技能、培养体育创新的思维 .并提出了培养创新能力的方法     

英汉语比较研究综述

对我国英汉语比较研究进行了综合性论述,其中包括研究的性质、范围与方法,研究的历史与现状及研究的宗旨与目的。文章坚持使用的术语是“比较”而不是“对比”,旨在倡导研究方法上从“重异”转移到“异同并重”或“重同”,因为这是人类思维本质的共同点所规定的。从近百年的英汉语比较研究的历史中,文章归纳出十个研究目的;一、促进对外汉语教学;二、促进现代汉语研究;三、深化英语教学改革;四、深化汉语教学改革;五、为翻译学建设打基础;六、革新英汉、汉英词典编纂工作;七、革新现代汉语词典编纂工作;八、深化对语言本质的认识;九、促进英汉语类型学研究;十、进一步认识语言与思维及文化的关系。     

高校后勤社会化改革的现实意义

高等学校后勤社会化改革是适应市场经济体制与日益发展的高等教育需要之间的唯一出路，也是我国高等教育发展史上的一场深刻革命。     

加速普通高校科研发展的理论思考

结合近年来普通高校科研工作的实际，运用邓小平的科技理论、高校管理思想等探讨加速普通高校科研发展的思路。     

Theory of interfacial phase transitions in surfactant systems

The spin-1 Ising model, which is equivalent to the three-component lattice gas model, is used to study wetting transitions in three-component surfactant systems consisting of an oil, water, and a nonionic surfactant. Phase equilibria, interfacial profiles, and interfacial tensions for three-phase equilibrium are determined in mean field approximation, for a wide range of temperature and interaction parameters. Surfactant interaction parameters are found to strongly influence interfacial tensions, reducing them in some cases to ultralow values. Interfacial tensions are used to determine whether the middle phase, rich in surfactant, wets or does not wet the interface between the oil-rich and water-rich phases. By varying temperature and interaction parameters, a wetting transition is located and found to be of the first order. Comparison is made with recent experimental results on wetting transitions in ternary surfactant systems.This paper is dedicated to J. K. Percus in honor of his 65th birthday.     

Three New Polyoxygenated Steroids from Two Species of the South China Sea Gorgonian Muricella flexuosa and Menella verrucosa Brundin

Three new polyoxygenated steroids, muricesteroid ( 1 ), and menellsteroids A ( 2 ) and B ( 3 ), were isolated from two species of the South China Sea gorgonian Muricella flexuosa and Menella verrucosa Brundin , respectively. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis, chemical methods and comparison with known related compounds.     

空气/水界面水分子的取向和运动

对四种不同的实验构型下空气／水界面自由O-H键在3700cm~(-1)的和频振动光谱的分析表明,水分子在空气／水界面的取向运动只可能是在平衡位置附近有限角度之内的受限转动。界面水分子的自由O-H键取向距界面法线约33°,而取向分布或运动的宽度不超过15°。这一图像显著地不同于Wei等人(Phys. Rev. Lett.86,4799(2001))只通过单一的SFG实验构型所得出结论,即：空气／水界面的水分子在超快的振动弛豫时间内在很大的角度范围内运动。     

A method for calculating invariant subspaces of symmetric hyperbolic equations

An algorithm is constructed for calculating invariant subspaces of symmetric hyperbolic systems arising in electromagnetic, acoustic, and elasticity problems. Discrete approximations are calculated for subspaces that correspond to minimal eigenvalues and smooth eigenfunctions. Difficulties related to the presence of an infinite-dimensional kernel in the differential operator are successfully handled. The efficiency of the algorithm is demonstrated using acoustics equations.