ε′对旋光光纤特性影响的理论分析与计算

通过对旋光光纤基本理论的讨论，以ε′为自变量为旋光光纤的基本参量和电磁场分量进行了数值分析，得出了相应的计算图表，另外，通过对实际的旋光光纤进行旋光角测量和进一步分析，论证了ε′与偏置磁场之间具有简单而明确的线性关系。这使得原本复杂的张量介电常量矩阵的求解变得非常简单。     

Preparation and nonisothermal crystallization behavior of polyamide 6/montmorillonite nanocomposites

Polyamide 6 (PA6)/montmorillonite (MMT) nanocomposites were prepared via melt intercalation. The structure, mechanical properties, and nonisothermal crystallization kinetics of PA6/MMT nanocomposites were investigated by X‐ray diffraction (XRD), tensile and impact tests, and differential scanning calorimetry (DSC). Before melt compounding, MMT was treated with an organic surfactant agent. XRD traces showed that PA6 crystallizes exclusively in γ‐crystalline structure within the nanocomposites. Tensile measurements showed that the MMT additions are beneficial in improving the strength and the stiffness of PA6, at the expense of tensile ductility. Impact tests revealed that the impact strength of PA6/MMT nanocomposites tended to decrease with increasing MMT content. The nonisothermal crystallization DSC data were analyzed by Avrami, Ozawa, modified Avrami‐Ozawa, and Nedkov methods. The validity of these empirical equations on the nonisothermal crystallization process of PA6/MMT nanocomposites is discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2878–2891, 2004     

用样条函数表示非球面方程式的光线追迹

提出用样条函数来表示非球面方程式,它优于一般的非球面方程式表示法,便于计算。     

An LP estimate for Maxwell's equations with source term

In this Note we establish an interior L^p-type estimate for the solutions of Maxwell's equations with source term in a domain filled with two different materials separated by a $\text{C}{}^2$ interface. Due to the singularity of the dielectric permittivity, the usual elliptic estimates cannot be applied directly. A special curl–div decomposition is introduced for the electric field to reduce the problem to an elliptic equation in divergence form with discontinuous coefficients. The potential theory analysis and the jump condition lead to the L^p estimates which are superior to the straightforward Nash–Moser estimates. The reduction procedure is expected to be useful for numerical simulation. Such an estimate is crucial for solving nonlinear Maxwell's equations that arise for example in the modeling of nonlinear optics. To cite this article: G. Bao et al., C. R. Acad. Sci. Paris, Ser. I 337 (2003).     

Digital speckle correlation method with compensation technique for strain field measurements

In the strain field measurements, especially in large strain field measurements, the correlation coefficient values obtained by the digital speckle correlation method are usually very low due to the relative pixel movement of the subset. The measuring error, therefore, is increased. A primary method, that is called compensation algorithm, is introduced for improving the correlation coefficient. A flow scheme with the compensation algorithm of our software is developed and some improved techniques for reducing the calculation time and error are discussed in the paper. After obtaining a set of displacement data with high correlation coefficient, a de-noise wavelet processing is adopted. It is obvious that the measuring accuracy of the strain field is better then before. A strain field of testing experiment is performed with this compensation technique. The correlation coefficients can increase from 0.70 to 0.99, which will be of much benefit for the improvements of the measuring accuracy.     

STABILITY OF SOLUTIONS FOR THE RECURSIVE SEQUENCE x_(n+1) =α-βx_n/γ+g(x_(n-1),…,x_(n-k))

In this paper, we study the stability of a class of recursive sequence under certain conditions.     

电磁场的不变量的求证方法讨论

用几种不同的方法对电磁场的不变量进行了求证和讨论，指出每种方法都可以归结为利用四维协变张量元素本身构造出洛伦兹不变量。     

关于Fuzzy拓扑线性空间的某些结果

本文给出了Ｆｕｚｚｙ拓扑线性空间的若干特征刻划，简化了判断Ｆｕｚｚｙ拓扑线性空间的条件，研究了Ｆｕｚｚｙ拓扑线性空间的层次结构，揭示了Ｆｕｚｚｙ拓扑线性空间与分明拓扑线性空间的内在联系，得到了Ｆｕｚｚｙ拓扑线性空间的“平移不变性”与“局部凸性”都是可截性质。     

Synthesis and properties of side chain liquid crystalline ionomers containing quaternary ammonium salt groups

New thermotropic side chain liquid crystalline ionomers (LCIs), containing 4-(4-allyloxybenzyloxy)-4'-alkoxybiphenyl (IM) as mesogenic unit and allyltriethylammonium bromide (ATAB) as non-mesogenic unit, were synthesized by graft copolymerization upon polymethylhydrosiloxane. The chemical structures of the polymers were confirmed by IR spectroscopy. Differential scanning calorimetry (DSC) was used to measure the thermal properties of these polymers; the mesogenic properties were characterized by polarizing optical micrography, DSC and X-ray diffraction. The influence of the alkoxy chain length on the clearing temperatures of the ionomers is clearly shown in an odd-even effect, similar to other side chain liquid crystal polymers. The mesomorphic behaviour of the ionomers is compared with that of isomeric ionomers synthesized in previous work. The results demonstrate that the phase behaviour of the two series of isomeric ionomers is similar, but with the difference that the melting temperature of ionomers with biphenyl located at the end of the mesogen is higher than for ionomers with biphenyl located at the middle of the mesogen. The latter are more useful for smectic orientational order than the former.