On rates of convergence of information theoretic criterion in rank determination of one-way random effects models

In this paper, upper bounds on the probabilities of wrong determination of the rank of covariance matrix of random effects in one-way random effects models are given, based on the information theoretic criterion. Under weak conditions, the bounds are shown of exponential-type.The work was partially supported by Natural Sciences and Engineering Research Council of Canada and Faculty Research Grant, Faculty of Arts, York University.     

一类独立随机变量均值中参数的估计

本文给出了独立随机变量均值中参数ａ＝（ａ１，…，ａｐ）′的估计量（ａ１Ｘ１，…，ａｐＸｐ）′在加权平方和损失下为可容许估计的充要条件及在一般损失Ｌｖ下为可容许估计的充分条件（在线性估计类中）。     

薄膜电致发光器件中SiO2加速作用的直接证据

本文通过包含CdS层的薄膜电致发光(TFEL)器件的有关特性的研究,直接证明了SIO₂对CdS中产生的电子有良好的加速作用,并获得了阈值电压低、B-V特性好,亮度较高的红色TFEL器件.我们将硫化镉蒸镀于电致发光器件中,测量这些器件的电学和光学特性,发现含CdS的样品的传导电荷明显大于不含CdS的样品,这说明硫化镉层可以提供较多的电子.但是,样品ITO/SiO₂/ZnS:Sm³⁺/SiO₂/CdS/Al的发光效率低于不含硫化镐的样品,这说明这些电子在进入ZnS层的过程中能量有所降低.为了提高这些电子的能量,我们制备了样品ITO/SiO₂/ZnS:Sm³⁺/SiO₂/CdS/Al,使硫化镉中产生的电子先经过SiO₂层,再进入发光层.测量结果表明这一样品的最大亮度和发光效率与上述含硫化镉的样品相比分别提高了2.5个和0.5个数量级,与不含硫化镉的样品的亮度接近,但其阈值电压较低,亮度-电压(B-V)曲线上升部分较陡,且有一段饱和区.在这一样品达到饱和的电压下,不含硫化镉的样品才刚刚起亮,这说明该样品的发光主要是由于硫化镉增加的电子数目对发光的贡献.同时这些电子在SiO₂中得到了明显的加速.     

Trimmed sums of i.i.d. Banach space valued random variables

Limit laws for trimmed sums of triangular arrays of i.i.d. Banach space valued random variables are studied. It is shown that if the array belongs to the domain of attraction of an infinitely divisible law without Gaussian component on a separable Banach space of type 2, then the trimmed sum converges weakly to a nondegenerate Banach space valued random variable.     

Small random perturbations of one-dimensional diffusion processes

In the present paper we consider the small random perturbations of one-dimensional diffusion processes. By virtue of stochastic analysis methods, we investigate the asymptotics of the mean exit times and probabilistical estimates of the exit times as the perturbations tend to zero. Partially supported by the Young Teachers Foundation of Beijing Institute of Technology     

Measurement of the transverse kinetic energies of argon recoil ions produced in 120 MeV -Ar collisions

Measurements were carried out to deduce the transverse kinetic energies of highly charged argon recoil ions produced in single collisions of 120 MeV ions with argon atoms in which the post collision charge states of the projectiles were not determined. A time of flight spectrometer was designed and fabricated to detect the charge states of recoils. Experimental procedures for optimizing the spectrometer for extraction, transmission and detection of recoils are described. A simple approach for determining the transverse kinetic energy of the recoil ions from FWHM of the peaks is reported. This method is shown to be independent of the choice of collision partners and requires only the knowledge of the physical values of “optimized parameters” of time-of-flight spectrometer used in the experiment. The transverse kinetic energy of the recoil ions determined from the present approach is found to vary from 0.03 eV for to 4.02 eV for Ar¹⁰⁺. These values are compared with the results reported by earlier workers and are shown to follow a q²-behaviour up to a charge state q =8+ of the recoil ions. Received: 5 February 1998 / Revised: 8 June 1998 / Accepted: 11 June 1998     

随机介质ZnO激光的一种整体效应模型

从实验现象出发建立了无序介质激光的一种整体散射效应物理模型，认为无序介质激光是无序介质中局域-非周期-类结构与相匹配的抽运光相互作用的结果.并以ZnO粉末激光参数为例进行数值模拟，结果与实验定性符合. 关键词： 无序增益介质 局域-非周期-类结构     

关于矩阵Kronecker积的谱半径的不等式

本文证明了矩阵的 Kronecker积的谱半径的两个不等式     

Universal fluctuations in the support of the random walk

A random walk starts from the origin of ad-dimensional lattice. The occupation numbern(x,t) equals unity if aftert steps site x has been visited by the walk, and zero otherwise. We study translationally invariant sumsM(t) of observables defined locally on the field of occupation numbers. Examples are the numberS(t) of visited sites, the areaE(t) of the (appropriately defined) surface of the set of visited sites, and, in dimension d=3, the Euler index of this surface. Ind≤ 3, theaverages - M(t) all increase linearly witht ast ® ∞. We show that in d=3, to leading order in an asymptotic expansion int, thedeviations from average ΔM(t) = M(t) -M(t) are, up to a normalization, allidentical to a single “universal” random variable. This result resembles an earlier one in dimensiond=2; we show that this universality breaks down ford>3.