Geometric Characterizations for Subgroups of PU（1, n; C）

In this paper, we discuss non-elementary subgroups and discontinuous subgroups of PU(1,n; C), and give their geometric characterizations.     

一类两点边值问题的多重非负解

该文考虑两点边值问题[1/q(t)][q(t)y′(t)]′+p(t)f(y(t))= 0,λ_1 y(α)-λ_2y′(α)=0 and y(β)=B非负解的存在性, 其中p(t)可能在t=α或t=β附近具有奇异性, f(0)≥0, lim_(y→+∞)f(y)/y=+∞, 并且存在y>0, 使得f(y)<0.      

He原子与HF分子碰撞截面的量子力学计算

用量子力学密耦近似方法计算了入射氦原子能量E=88?meV时,He-HF碰撞,弹性散射分波截面(00-00)和非弹性散射00-01及00-02分波截面.计算结果与公认较好的Moszynski等人的SAPT势比较接近.     

基于阿贝尔黑格斯变量的杨-米尔斯理论的红外阿贝尔化

通过SU(2)规范场的法捷耶夫-Niemi分解给出了有效阿贝尔-黑格斯型作用量的 一个计算方法. 具体指出了该分解中所用的自然规范固定以及阿贝尔投射与杨-米尔斯理论的红外动力学之间的内在关系. 推导出了色电场的一个伦敦型方程.     

Decoherence Induced by Spin Chain Environment

We study the decoherence process of an exact solvable model that consists of a central spin-1/2 coupling to the surrounding anisotropy spin-1/2 chain in transverse fields. The Loschrnidt echo is calculated to study the character of decoherence with different degree of anisotropy. Our results show that the degree of anisotropy γ greatly affects the decoherence process of the central spin-system when the spin chain is in weak transverse fields, but it gives weak effect in the strong transverse field. The decoherence process of the central system changed dramatically along the line of the critical points, and this may be explained as the reflection of quantum phase transitions.     

相位差与q变形广义相干叠加态的压缩特性

对于q变形的非简谐振子广义相干态的叠加态β〉+eiφβeiδ〉,其量子涨落的可能高阶压缩阶数可以表示为k≠2πn/δ,这里n是整数.当δ=π时,压缩阶数不能是偶数即只能是奇数,这正是q变形非简谐振子广义奇偶相干态的结果.由此表明参数相位差δ对决定q变形的非简谐振子广义相干态叠加态的高阶压缩阶数起决定性作用.     

Identical Superdeformed Bands in ^171Ta and ^173Re

The rotational band built on the i13/2 proton [660,1/2] Nilsson state in ^173Re is proven to be identical to that in ^171Ta.The close similarity of the two bands in ^171Ta and ^173Re suggests that the ^173Re nucleus with the odd proton based on the i13/2 [660,1/2] Nilsson state may be triaxially superdeformed.     

量子化电磁场中的非经典电子波包:电子与光子的纠缠

文中研究了量子化电磁场中非经典电子波包的运动。当初始光子态是Fock态时，随着电子和光子所组成系统的演化，初台可分离的电子态和光子态会互相纠缠，而且电子几率密度的时间演化呈非经典的分岔和汇合的现象。基到这些非经典特征，电子可以在光子场中被加速和减速，而系统保持能量守恒。     

Covariant Perturbation Theory of Non—Abelian Kinetic Theory

A “double perturbation” theory is presented in the framework of the kinetic theory of quark-gluon plasma.A solvable set of equations from the double perturbation are derived and proven to be gauge invariant.The Landau damping rate for the plasmon at zero momentum is shown to be a convergent series in correlators.     

非保守力学系统Nielsen方程的形式不变性

研究非保守力学系统Nielsen方程的形式不变性.给出非保守力学系统Nielsen方程的形式不变性的定义和判据,研究形式不变性和Noether对称性的关系,并举例说明结果的应用 关键词： 非保守力学系统 Nielsen方程 形式不变性 Noether对称性