理想微裂纹系统中的随机扩展效应

本文讨论了在理想微裂纹系统中,由于微裂纹的随机性扩展,对微裂纹统计演化产生的效应。文中提供了一般的理论框架,给出了便于处理的转移概率的表达式。最后,用数值计算的例子展示了随机模型的统计演化特征,并比较了与确定性扩展模型下统计演化的异同。     

Effect of Molecular Weight on Liquid Crystal Photoalignment by Photosensitive Polyester Containing Thrifluoromethyl Moieties

We investigate the liquid-crystal （LC） alignment direction on photoalignment films formed from photosensitive polyester containing thrifluoromethyl moieties （PPDA） with various molecular weights by crossed polarized optical microscopy. It is found that LC alignment behaviour changes with molecular weight of PPDA. The LC alignment on PPDA irradiated films with the highest molecular weight is homogeneous, while those with low and intermediate molecular weights are homeotropic. However, surface morphologies show weak dependence on molecular weight. The surfaces are smooth and there is no clear morphological anisotropy on these aligned films observed by an atomic force microscope. The surface energies of the irradiated films are also measured by using an indirect contact-angle method where both surface energy and its polar component, increase with increasing molecular weight. Different polar surface energies can be considered as a main reason for different alignment characteristics.     

小型风光互补发电演示装置

研制了适用于大学物理演示实验教学的小型风光互补发电演示装置,该装置由叶片、风力发电机、光伏太阳能电池板、控制器、蓄电池、逆变器、负载等几部分组成.整个系统以光电互补控制器为核心,经由风力发电机与光伏太阳能电池板将风能和太阳光能转变为电能,并将其储存于蓄电池中供负载使用.该装置展示了风力发电系统的组成,演示了风力发电原理和相关空气动力学原理.     

2-F-环氧丁烷与几种生物小分子间的赝氢键结构

采用密度泛函B3LYP(Becke,three-parameter,Lee-Yang-PaH)/6-311++G**和HF(Hartree Fock)/6-311++G**方法,从理论上探讨了2-F-环氧丁烷分别与几种常见而重要的生物小分子咪唑(Iminazole)、噻唑(Thiazole)和恶唑(Oxazo1e)等分子间的弱相互作用,发现分子间同时存在N…H常规氢键和C-F…H-C赝氢键结构.弱相互作用能计算表明3个复合物的相对稳定性相当.计算结果表明,在C-F…H-C赝氢键结构中,与电子的直接供体F密切相关的共价键C-F键长增大,伸缩振动的频率红移,而作为电子受体的H-C基团,其C-H键伸缩振动光谱蓝移;另外,电子密度拓扑性质表明C-F…H-C赝氢键的共价性及离子性均与常规氢键相当.     

Tritium planigraphy as a tool for studying the structural organization nanobiocomplexes

The tritium planigraphy method is based on the nonselective substitution of radioactive isotope tritium for hydrogen in hydrocarbon fragments of molecules by means of a chemical reaction involving hot tritium atoms. Data on the steric accessibility of the system components (macromolecules in the complex, amino acid residues, and even individual atomic groups of macromolecules) characterize the structure of the object. The method, applicable to substances in different phase states, has no restrictions on the molecular weight of the target. Tritium planigraphy, used equally successfully in both crystals and solutions, makes it possible to study fine changes in the structure. The main results of studies of the structure of nanosized biocompexes by tritium planigraphy are presented.     

中温固体氧化物燃料电池的基本性质测量

介绍了固体氧化物燃料电池的工作原理,测量了中温薄膜固体氧化物燃料电池的开路电压、放电曲线及功率曲线,并分析了电池内阻随电流密度的变化.     

立体化、创新型的光学课程教学体系与模式的研究

为了培养高水平的创新型人才,我们从精选课程教学内容、运用现代化的教学手段以及改革考核方式等方面对光学课程作了改革,取得了良好的教学效果.     

浙江省电力系统噪声综合治理研讨会在杭州举行

为贯彻执行江泽民主席2001年第60号令[中华人民共和国职业病防治法],浙江省电力工业局于2001年11月30日在杭州召开了所属各发电厂、电力公司、研究所等23个单位50名代表参加的噪声综     

具有若干$c_p$-可补子群的有限群

设$H$为有限群$G$的子群且$p$为整除群$G$的阶的素因子. 我们称$H$在$G$中为$c_p$-可补的,如果$G$中存在$H$的包含$H_G$的补子群$T$使得$H\cap T/H_G$为$p''$-群, 其中$H_G$为$H$在$G$中的核. 群$G$ 称$CS_p$-群, 如果$G$的所有$p$-子群都在$G$中$c_p$-可补. 本文,我们刻画具有若干$c_p$-可补$p$-子群的有限群的$p$-可解性和$p$-超可解性. 此外,我们给出$p$-可解群为$CS_p$-群的若干等价条件. 最后, 我们给出两个$CS_p$-群的直积为$CS_p$-群的判别准则. 我们的结果推广了近期的若干结论.     

静电场描绘的一种改进方法

本文介绍的是使用算术平均法作出等势线,描绘静电场。与课本中的方法进行比较,结果误差更小,更准确的描绘了静电场的分布。