Almost sure central limit theorems for random fields

A general almost sure limit theorem is presented for random fields. It is applied to obtain almost sure versions of some (functional) central limit theorems. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

On sum of 0–1 random variables II. Multivariate case

Summary Distribution of sum of vectors of 0–1 random variables is discussed generalizing the univariate results obtained in our previous article Takeuchi and Takemura (1987,Ann. Inst. Statist. Math.,39, 85–102). As in our previous article no assumption is made on the independence of the 0–1 random variables.     

中心力场低能散射分析

总结了一般短程中心力场低能散射的4种可能结果:1)微分截面有限且各向同性;2)微分截面有限且显著各向异性:3)零能共振;4)冉绍尔一汤森(Ramsauer-Townsend)效应.详细分析了各种结果出现的条件,指出其与零能解形式密切相关.计算了若干简单势场下的具体结果,印证了一般结论.     

Large deviation principles for sequences of logarithmically weighted means

In this paper we consider several examples of sequences of partial sums of triangular arrays of random variables {Xn:n?1}; in each case Xn converges weakly to an infinitely divisible distribution (a Poisson distribution or a centered Normal distribution). For each sequence we prove large deviation results for the logarithmically weighted means with speed function . We also prove a sample path large deviation principle for {Xn:n?1} defined by , where σ²∈(0,∞) and {Un:n?1} is a sequence of independent standard Brownian motions.     

The method of central difference for the inverse time-dependent heat source problem

This paper investigates the inverse problem of determining a heat source in a parabolic equation where data are given at some fixed location. This problem is ill-posed, i.e., the solution (if it exists) does not depend continuously on the data. A central difference regularization method is given and an order optimal stability estimate is obtained. Numerical results for several benchmark test problems indicate that the central difference regularization method is an accurate and flexible method to determine the unknown time-dependent heat source.     

中央与地方共建特色物理实验室的研究与实践

依托生物物理学重点学科,以应用物理的理论和方法技术研究海洋生物与环境等问题为切入点,结合中央与地方共建特色实验室项目,在将物理实验室提升为具有产学研一体化功能、海洋特色鲜明的现代化物理实验教学中心方面进行了研究与实践,取得了阶段性成果.     

Structure of a Class of Rank Two Lie Conformal Algebras

Let β be a complex number,and a class of non-semisimple and non-solvable rank two Lie conformal algebras-(L)(β) are introduced.In this paper,conformal derivations,conformal quasiderivations,generalized conformal derivations and conformal biderivations of (L)(β) are studied.Besides,central extensions and conformal modules of rank one of (L)(β) are determined.     

Spherical-Symmetry and Spin Effects on the Uncertainty Measures of Multidimensional Quantum Systems with Central Potentials

The spreading of the stationary states of the multidimensional single-particle systems with a central potential is quantified by means of Heisenberg-like measures (radial and logarithmic expectation values) and entropy-like quantities (Fisher, Shannon, Rényi) of position and momentum probability densities. Since the potential is assumed to be analytically unknown, these dispersion and information-theoretical measures are given by means of inequality-type relations which are explicitly shown to depend on dimensionality and state’s angular hyperquantum numbers. The spherical-symmetry and spin effects on these spreading properties are obtained by use of various integral inequalities (Daubechies–Thakkar, Lieb–Thirring, Redheffer–Weyl, ...) and a variational approach based on the extremization of entropy-like measures. Emphasis is placed on the uncertainty relations, upon which the essential reason of the probabilistic theory of quantum systems relies.     

电子高新技术推动下关于疲劳研究的新进展--中枢性运动疲劳与某些神经递质的研究

本文从大脑的中枢机制对运动性疲劳进行了阐述,总结了神经递质与中枢疲劳的关系。神经递质是由神经细胞分泌并作用于效应细胞,使其发生特异性功能改变的一类活性物质,也是中枢神经系统产生的敏感性物质,与运动性中枢疲劳有着密切的关系。本文采用文献综述法,从生理学角度,论述了5-羟色胺、多巴胺、乙酰胆碱、氨、一氧化氮等物质与运动性中枢疲劳之间的关系,以期为运动性中枢疲劳的消除提供科学依据。     

基于非均匀测量矩阵的超分辨率全向图像重建

为解决折反射全向成像空间分辨率低和分布不均匀 的问题,将压缩感知(CS)理论引入折反射全向成像系统。基于单 位球面模型分析了折反射全向成像系统的空间分辨率分布规律,根据重构信号的均方误差(MSE)与稀疏度、测量次数的关系,设计了 基于全向图像分辨率的非均匀测量矩阵;通过设计的测量矩阵,将较多的传感资源分配给全 向图像内环,而将较少的传感资源 分配给外环,从而对经过镜面反射的场景进行采集,得到观测场景的非均匀压缩采样;最后 通过线性Bregman迭代算法重构出 分辨率均匀的高分辨率图像。实验结果表明,本文方法得到的图像空间分辨率更高且分布更 为均匀,有效改善了全向成像的分辨率问题。