高Tc超导材料Bi_2Sr_2CuO_6和Bi_2Sr_2CaCu_2O_8的晶格振动对称性分析

本文运用群论方法,对高T_c Bi 系超导体中的Bi_2Sr_2CuO_(?)和Bi_2Sr_2CaCu_2O_8的晶格振动模进行了系统的对称性分类.给出了其布里渊区中(?)点,X 点和△线振动模式的对称分解和对称化基.     

探求高等数学中的对称美

高等数学中的对称关分为三类：形式和结构的对称性、命题关系中的对偶性及解题策略中的对称法。     

应用对称性研究碱金属原子的能级分裂

应用对称性研究了碱金属原子在无外场而有自旋轨道耦合作用和在均匀强弱磁场中的能级分裂，并计算了其能级一级近似值。     

Why the Afshar experiment does not refute complementarity

A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to what appears to be a “which-way” measurement, an interference pattern exists. Afshar has claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation easily accommodates the result. It is also shown that the Afshar experiment is analogous in key respects to a spin one-half particle prepared as “spin up along x”, subjected to a nondestructive confirmation of that preparation, and post-selected in a specific state of spin along z. The terminology “which-way” or “which-slit” is critiqued; it is argued that this usage by both Afshar and his critics is misleading and has contributed to confusion surrounding the interpretation of the experiment. Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. In addition, some new inferences about the interpretation of delayed choice experiments are drawn from the analysis.     

On some tests-based projection pursuit for elliptical symmetry of a high-dimensional distribution

Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative. The asymptotic properties of bootstrap approximation are investigated. Furthermore, for computational reasons, an approximation for the statistics, based on the number theoretic method, is suggested. An erratum to this article is available at .     

具有公共对称面的两个二次回转面的相贯线

本文论述了常见的两个二次回转面轴线相交和平等时,其相贯线在公共对称面（投影面）的投影分别为双曲线和抛物线,只有在特殊情况下是直线,椭圆和圆,并举例说明在计算机上绘图的方法。     

对称性对二相互作用玻色子耦合系数的制约

给出了一般形式下二体相互作用玻色系统对角化的一般方法,讨论了能对角化的条件,得到了制约耦合系数的两个关系式。     

分形几何中的美--分形理论哲学探索之一

从美学角度指出了分形几何是科学与艺术的结合.进而,探讨了分形几何中美的特征:统一性、对称性与奇异性.     

磁空间群Pб_ 3/m''''m’c''''不可约共表示的计算

群表示理论在群论的发展和应用中占有十分重要的地位,它对求解C-G系数,同位标量因子及母分系数是必不可少的。本文主要以P6_3”m′m′c′的对称点L点为例,应用诱导表示的方法,介绍磁空间群不可约共表示的计算方法。     

基于Bresenham算法的四步画直线算法

通过分析计算机图形学中的画直线的Bresenham算法，以及由此改进的“对称算法”、“二步法”，提出将“对称算法”和“二步法”结合形成“4—点画线算法”，与Bresenham算法相比，该算法可以将画线效率提高近2倍。