Decoration of disclinations by solidification-induced band texture and focal-conic texture for a low-molar-mass liquid crystal

Two decoration techniques, solidification-induced band texture decora tion and focal-conictexture decoration, have been established to exhibit the director field of disclinations in a low-molar-mass methacrylate liquid crystal. The disclinations with strength s = 1/2 and s = ±1 are observed by the two decor ation methods. For the solidification-induced band texture decoration, the molecular orientation is perpendicular to the direction of the band. While for focal- conictexture decoration, it has been proved by the results of IR dichroism that the direction of the director is parallel to the direction of the focal-conic. Therefore, the sketch map of the molecular director filed can be mapped according to the morphological pattern of the solidification-induced band textureor focal-conic texture.     

E-n-伪矩形性拟正则半群

本文是在[1]的基础上,将半群s的幂等元集E(S)由埋想推广为n-伪理想,然后来给出S的结构。本文未用到格林关系,因而证明有别于[1],而且[1]是我们的特例。     

带的双闭子带和自由幂等元半环

给出带的双闭子带和它的性质及特征。在此基础上，给出加法半群为半格的幂等元半环簇中的自由对象。     

跨文化交际:文化理解的桥梁--文化空缺词

文化空缺词是由于不同民族对文化理解的差异而反映在语言上的一种符号或语义空缺现象。它承载着不同的民族文化特色和文化信息，蕴涵着丰富的民族文化色彩，与使用该语言人民的历史文化、风俗民情密切相关；文化空缺词又是了解一个民族文化最有效的途径，它留给不同语言民族的人们更多的想象空间和发挥空间，为跨文化交流提供了一扇窗口。人们通过对其内涵的发掘、研究和阐述，可以增进不同民族的人民之间的相互了解和沟通，从而使跨文化言语交际得以实现。     

Au吸附在GaAs（110表面的研究

研究了Au吸附在GaAs(110)表面的吸附构型,并计算了表面态密度和表面能带结构.计算结果表明,可以认定Au与Ga的悬挂键杂化成键,从而引起2条附加的能带,一条位于禁带之中,距价带顶为0.9ev;另一条与价带共振,离价带顶为0.7ev,所得结果与实验结果相一致.     

基于反相对称法的双边带通信系统

给出了一种基于反相对称法的双边带通信系统的实现方法,通过MATLAB仿真,证实了这种方法的可行性。     

Time‐simultaneous prediction band for a time series

I propose principles and methods for the construction of a time‐simultaneous prediction band for a univariate time series. The methods are entirely based on a learning sample of time trajectories, and make no parametric assumption about its distribution. Hence, the methods are general and widely applicable. The expected coverage probability of a band can be estimated by a bootstrap procedure. The estimate is likely to be less than the nominal level. Expected lack of coverage can be compensated for by increasing the coverage in the learning sample. Applications to simulated and empirical data illustrate the methods. Copyright © 2007 John Wiley & Sons, Ltd.     

Genetic algorithm-based wide-band deterministic maximum likelihood direction finding algorithm

1 .INTRODUCTIONThe problemof esti mating direction of arriving waveusing array signal processing has wide applications inradar ,sonar ,seismology,astronomy and mobile andsatellite communication system, and has receivedmuch attentionin recent years .But the current liter-ature about direction finding algorithmpays more at-tention to narrow-band signal ,that is to say band-width of signal is far smaller than center frequency ofsignal and so envelop of signal keeps invariant in thesensors of …     

消除电磁搅拌连铸坯中“白亮带”的试验研究

针对电磁搅拌连铸坯中的“白亮带”问题进行试验研究和理论分析．结果表明：铸坯凝固过程中电磁搅拌引起的钢液运动特点是能否产生“白亮带”的关键．特殊的电磁搅拌方式有效地抑制“白亮带”的产生．     

对称稀疏矩阵三对角化并行算法

本文用Ｇｉｖｅｎｓ变换,给出一个对称稀疏矩阵的三对角化并行算法,具有很好的并行加速及效率,由于充分考虑了矩阵的稀疏性,使算法中数据存储及通讯相当节省。