非晶半导体光致发光的温度依赖关系

研究了a-Si:H,a-Si:H,F,a-Si:H,Cl以及a-Si:H,Cl,O等非晶硅薄膜光致发光的温度依赖关系。测量了各种样品的无辐射跃迁激活能ε,并试图寻求激活能ε与样品的制备条件和结构之间的关系;同时从发光强度的温度相关性确定了带尾态密度分布参数T0,以及T0与发光光谱形状之间的关系。并将实验结果与瞬态光电导的数据进行了比较。     

Ab initio方法研究~(40)Ca~(35)Cl分子的自旋轨道耦合效应和跃迁性质

本文研究了~(40)Ca~(35)Cl分子低态的自旋轨道耦合分裂以及获得更精确的光谱常数和更高的激发态.以从头算理论为基础,使用多参考组态相互作用方法获得了该分子的势能曲线和自旋轨道分裂,之后求解径向一维薛定谔方程获得光谱常数.得到了~(40)Ca~(35)Cl分子7个Λ-S低电子态的势能曲线和永久偶极矩,以及A~2Π→~2Σ~+,1~2Δ和C~2Π→~2Σ~+,1~2Δ跃迁的跃迁偶极矩,得到的光谱常数(不管是考虑了自旋轨道耦合(SOC)还是没有考虑SOC)与实验值非常符合,且要好于之前的理论计算结果 .值得注意的是,目前的计算还首次得到了C~2Π→~2Σ+,1~2Δ跃迁的跃迁性质,为之后实验观察~(40)Ca~(35)Cl分子的高激发态光谱和跃迁性质提供有益的理论参考.     

Probabilistic and Average Linear Widths of Sobolev Space with Gaussian Measure in L \infty-Norm

In this paper we investigate the probabilistic linear $(n,\delta)$-widths and $p$-average linear $n$-widths of the Sobolev space $W^r_2$ equipped with the Gaussian measure $\mu$ in the $L_{\infty}$-norm, and determine the asymptotic equalities \begin{eqnarray*} \lambda_{n,\delta}(W^r_2,\mu,L_{\infty}) &\asymp&\frac{\sqrt{\ln (n/\delta)}}{n^{r+(s-1)/2}},\\[3pt] \lambda^{(a)}_n(W^r_2,\mu,L_{\infty})_p &\asymp&\frac{\sqrt{\ln n}}{n^{r+(s-1)/2}}, \qquad 0 < p < \infty. \end{eqnarray*}     

Normal families and uniqueness theorems for entire functions

There exists a set S with 3 elements such that if f is a non-constant entire function satisfying E(S,f)=E(S,f′), then f≡f′. The number 3 is best possible. The proof uses the theory of normal families in an essential way.     

The skew elliptical distributions and their quadratic forms

In this paper, a family of the skew elliptical distributions is defined and investigated. Some basic properties, such as stochastic representation, marginal and conditional distributions, distribution under linear transformations, moments and moment generating function are derived. The joint distribution of several quadratic forms is obtained. An example is given to show that the distributions of some statistics as the functions of the quadratic forms can be derived for various applications.     

Blind Channel Identification Based on Noisy Observation by Stochastic Approximation Method

A stochastic approximation algorithm for estimating multichannel coefficients is proposed, and the estimate is proved to converge to the true parameters a.s. up-to a constant scaling factor. The estimate is updated after receiving each new observation, so the output data need not be collected in advance. The input signal is allowed to be dependent and the observation is allowed to be corrupted by noise, but no noise statistics are used in the estimation algorithm.     

YBa2Cu1-xCox(Cu1-yZny)2Oz体系的Co,Zn共同掺杂效应

本文报道通过对YBa₂Cu_1-xCo_x(Cu_1-yZn_y)₂O_z(0≤x,y≤0.1)体系晶体结构、氧含量、正常态电阻-温度关系、Hall效应以及超导临界温度等的综合测量,发现随着Co和Zn含量的增加,体系经历了从正交结构的超导金属向四方结构的非超导半导体的转变,超导临界温度T_c和载流子浓度n_h均迅速下降,Co 关键词：     

Yb原子高激发态的斯塔克光谱

采用ππ偏振激光，通过两步激发和光电离方法，在０－１５４Ｖ／ｃｍ电场范围内，测定了Ｙｂ原子ｎ－１８附近ｍ＝０的斯塔克光谱，首次把包含斯塔克效应的能量矩阵对角化方法推广到Ｙｂ原子，所获得的理论斯塔克图与实验结果基本符合，观察到低场中斯塔克簇随电场增加呈现线性结构以及＾１Ｐ１态与斯塔克簇在抗交叉过程中振子强度发生转移的现象，讨论了结构与量子亏损的关系。     

正则Cosine算子函数的乘积扰动定理

本文研究了正则cosine算子函数的乘积扰动性,在正则化算子C的值域不 一定稠密的一般情形下,获得了若干正则cosine算子函数的乘积扰动定理.     

过渡金属化合物OsB2与OsO2低压缩性的第一性原理计算研究

利用基于密度泛函理论平面波赝势法的第一性原理计算,研究了过渡金属化合物OsB2和OsO2的金红石相、黄铁矿相与萤石相三种结构在高压下的状态方程和结构特性以及OsO2可能的高压相变.理论计算结果支持OsB2与OsO2的萤石相是潜在超低可压缩性的硬性材料.同时,也分析了它们的电子结构,力求理解大体变模量和高硬度的微观机制.结果表明,可以利用过渡金属高的价电子浓度,掺入硼、氧、碳、氮等轻的元素形成强的方向键,这可能提供了一种合成超硬材料的新途径.