稀士配合物Y(3-PYA)_32·H_2O(0.2%Gd)的ESR光谱

测定了配合物Y( 3-PYA) 32·H2 O( 0 .2 %Gd)的单晶体在室温下的电子自旋共振光谱 .结果表明 ,只有当磁场H和晶轴b平行时 ,即晶体绕b旋转时 ,才存在一个C2 ,并求得自旋因子 g .     

A most bias-robust estimate of the location parameter: a general existence theorem

It is well known (HUBER, 1981) that, for symmetrical and unimodal parent distributions, the most asymptotic-bias-robust estimate of the location parameter under e-contamination is the sample median. We show, without any assumptions on symmetry and unimodality, that the most bias-robust estimate exists for every finite sample size. The main result of the paper consists in constructing an appropriate statistical model which differs from that considered by HUBER     

Exact predictors for a generalized ar(1) process with an ar(1) parameter

The generalized AR(1) process y _t = a _t y _t-1+ v _t is considered, where the parameter a _t follows the AR(1) process a _t = Ga _t-1+ w _t.Assuming that V _t and w _t are Gaussian and independent, the first six exact predictors for future values of y _t are derived. These exact predictors are compared with Box-Jenkins -type approximations. MACSYMA, a computer algebra program, is utilized in the derivation of the predictors.     

Improved estimation of the scale parameter, the hazard rate parameter and the ratio of the scale parameters in exponential distributions: An integrated approach

We give new classes of Strawderman-type improved estimators for the scale parameter σ₂ and the hazard rate parameter 1/σ₁ of the exponential distributions E(μ₂,σ₂) and E(μ₁,σ₁) under the entropy loss. We then use these estimators to construct improved estimators for the ratio ρ=σ₂/σ₁. The sampling framework we consider integrates important life-testing schemes separately studied in the literature so far, namely, (i) i.i.d. sampling, (ii) Type-II censoring, (iii) progressive Type-II censoring and adaptive progressive Type-II censoring and (iv) record values data. Furthermore, we establish simple identities connecting the risk functions of the estimators of σ₂ and 1/σ₁ and those of ρ that have a direct impact on studying the risk behavior of the latter estimators. Finally, we indicate that no matter which of the above life-testing schemes is employed for the estimation of σ₂, 1/σ₁ or ρ, the corresponding improved estimator, which may be of Stein-type or Brewster and Zidek-type or Strawderman-type, will offer the same improvement over the usual estimator as long as the number of observed complete failure times is the same for each scheme. Our results unify and extend existing results on the estimation of exponential scale parameters in one or two populations.     

金融市场Tsallis参数的估计及其应用

首先介绍Tsallis分布及其在金融市场中的应用背景，对Tsallis分布中的Tsallis参数给出其估计的原理与步骤；然后利用外汇市场数据和中国A股市场部分股价数据进行实证分析，分别得到几种主要货币对之间汇价和中国几只A股股价运行过程中的Tsallis参数的估计值；最后给出了Tsallis参数估计在公司信用风险计量和公司股票欧式看涨期权价值计算两方面的应用，得到更合理的应用结果。     

一类集中参数系统最优控制的存在性及必要条件

研究了由一类集中参数系统所支配的最优控制问题.首先应用极小化序列方法证明了最优控制的存在性.然后采用古典变分法,以变分不等式的形式给出了最优控制所满足的必要条件.     

视超光速现象与成束模型

本文从视超光速源样品出发，对核主导系数与成束指标之间的关系，流量密度与红移之间的关系作了一定的研究。研究结果表明：核主导系数不仅是一个方向指示系数同时也是一个成束指示系数。并且核主导系数与亮温度均可作为成束指示系数；射电辐射被大大地放大了，而X射线辐射的放大效应却很小。     

Estimation of a finite population distribution function based on a linear model with unknown heteroscedastic errors

The authors consider a finite population ρ = {(Y_k, x_k), k = 1,…,N} conforming to a linear superpopulation model with unknown heteroscedastic errors, the variances of which are values of a smooth enough function of the auxiliary variable X for their nonparametric estimation. They describe a method of the Chambers‐Dunstan type for estimation of the distribution of {Y_k, k = 1,…, N} from a sample drawn from without replacement, and determine the asymptotic distribution of its estimation error. They also consider estimation of its mean squared error in particular cases, evaluating both the analytical estimator derived by “plugging‐in” the asymptotic variance, and a bootstrap approach that is also applicable to estimation of parameters other than mean squared error. These proposed methods are compared with some common competitors in simulation studies.     

C语言的公理语义(Ⅱ)──函数

从公理语义的角度，讨论C语言的重要机制─—函数─—的语义。