由气相色谱程序升温数据计算恒温保留指数

提出了一种由程序升温数据推算恒温保留指数的计算方法,采用实验数据关联死时间和温度的关系,引入等效温度作为间接变量进行最优化。应用于Ｃ＿５～Ｃ＿９正构烷烃和Ｃ＿６烯烃的数据表明该法适应性强、精确度高,推算的恒温保留指数可作为定性依据。     

Novel Photosensitive Fluorinated Poly(arylene ether) Having Zero Birefringence

Summary: A novel photosensitive fluorinated poly(arylene ether) containing chalcone units was synthesized from decafluorinated chalcone and fluorinated bisphenol at low temperature. Upon UV irradiation, the refractive indices of the polymer film were decreased because of the reduction of electronic polarizability in the chalocone moiety. The decrease was more significant in the in‐plane direction than in the out‐of‐plane direction, and consequently, zero birefringence (at 632.8 nm) was obtained after 90 s of exposure.

The changes in the refractive indices and the birefringence of chalcone‐containing fluorinated poly(arylene ether) films synthesized and measured at 632.8 nm with respect to UV irradiation time.     

用自聚焦透镜作平行光束与单模光纤的最佳耦合

本文提出一种用两片自聚焦透镜组合而成的耦合系统,可以实现平行光束与单模光纤的最佳耦合.文中给出了该耦合系统的参数计算公式,并进行了计算机数字式计算,最后推导给出了最佳结构参数计算的解析公式.表明给出的耦合系统具有唯一最佳结构参数解,并且这种解具有和谐的对称性.     

Ti扩散Er3+:LiNbO3沟道波导的模式分析

本文采用有效折射率方法对Ti扩散Er³⁺:LiNbO₃沟道波导的模式特性进行了分析,分析中考虑了Er³⁺:LiNbO₃晶体的各向异性,并与变分法分析进行了比较,二者结果相一致。     

Surface reorientation dynamics of nematic liquid crystals

In this paper we report an experimental investigation on the dynamics of the azimuthal director reorientation at a nematic-solid interface. Three qualitatively different kinds of substrates have been investigated: I) intrinsically anisotropic SiO-substrates (-evaporation), II) isotropic SiO-substrates (-evaporation) and III) rubbed PVA-substrates. In the case II), an in-plane anisotropy was induced cooling slowly the thermotropic nematic liquid crystal (NLC) from the isotropic phase in the presence of a 0.75 T magnetic field. The reorientation dynamic of the surface azimuthal director angle at the switching-on and off of a magnetic (or electric) field has been investigated. All the substrates show comparable azimuthal anchoring energies and two dynamic regimes: a fast dynamic response, driven by the bulk director reorientation and an extremely slow reorientation. The slow dynamics is explained in terms of anisotropic adsorption of NLC molecules on the solid substrate and is well represented by a stretched exponential. Received 7 December 1998     

Quality assurance in analytical measurement

 The peculiarities of analytical measurement require to check characteristics of the error (its components) of the obtained analysis results to assure the quality of the measurements. This article deals with the various quality assurance procedures and algorithms which are used to check the quality indices, i.e. the accuracy, reproducibility, certainty and repeatability of analytical measurements: These procedures include: laboratory rapid control; Intra-laboratory statistical control (statistical selection control by alternative attribute, statistical selection control by quantity method of periodic check of the analysis procedure for conformity to the specified requirements) and external control (inter-laboratory control checks, inter-laboratory comparison tests, and intra-laboratory control algorithms carried out by the appropriate supervisory body.) in the separately taken laboratory. The respective algorithms, control plans and control requirements, specified according to the different control aims and assurance tasks, enable the quality and certianty of analytical information obtained in laboratories in Russia to be assured. Received: 9 November 1998 / Accepted: 24 November 1998     

一类平面齐次多项式系统的局部相图

平面系统在动力系统的研究中起着重要的和基础的作用．在实系数系统情况下,本文利用奇点指数和牛顿多边形方法,讨论了一类平面齐次多项式系统在其孤立点附近的相图,同时给出一些奇点稳定的充要条件．     

Amann三解定理的改进及其应用

本文对非线性泛函分析中著名的Ａｍａｎｎ三解定理作了本质性的改进,并将其结果应用到核函数不恒为正的Ｈａｍｍｅｒｓｔｅｉｎ型积分方程,得到了新的结论．     

扭化的Atiyah-Singer算子(I)

本文证明黎曼流表上的ｄｅ Ｒｈａｍ以及Ｓｉｇｎａｔｕｒｅ算子都同构于扭化的Ａｔｉｙａｈ－Ｓｉｎｇｅｒ算子。这两类算子的局部指数定理和局部Ｌｅｆｓｃｈｅｔｚ不动点公式都可以从扭化的Ａｔｉｙａｈ－Ｓｉｎｇｅｒ算子得到。     

A mod 2 index theorem for the twisted Signature operator

A mod 2 index theorem for the twisted Signature operator on 4 _q + 1 dimensional manifolds is established. This result generalizes a result of Farber and Turaev, which was proved for the case of orthogonal flat bundles, to arbitrary real vector bundles. It also provides an analytic interpretation of the sign of the Poincare-Reidemeister scalar product defined by Farber and Turaev. Project partially supported by the National Natural Science Foundation of China (Grant No. 19525102), the Fok Ying-Tung Foundation and the Qiu Shi Foundation.