一类多偏差变元的n种群Lotka-Volterra模型的周期正解

本文研究了一类多偏差变元Lotka-Volterra种群模型的间期正解问题,利用重合度拓展定理和一些分析技巧,得到了周期正解存在性的新结果.与已有文献相比,本文所讨论的模型更具一般性,它包含了以前人们所研究的竞争-种群模型、捕食-种群模型等,而且估计先验界的方法也是全新的.     

木糖腺苷类似物的合成

糖部分修饰的核苷类似物,作为有效的抗肿瘤及抗病毒药物,受到广泛的注意。但木糖系列则研究得较少。据报道木糖苷也显示抗肿瘤活性,木糖腺苷虽呈一定的抗肿瘤活性,但毒性较大。为了进一步研究木糖苷类似物的药理作用,我们合成了一系列8-取代的β-D-呋喃型木糖基腺嘌呤。     

Consistency of change point estimators for symmetrical stable distribution with parameters shift

Assume that the characteristic indexαof stable distribution satisfies 1<α<2,and that the distribution is symmetrical about its mean.We consider the change point estimators for stable distribution withαor scale parameterβshift.For the one case that mean is a known constant,ifαorβchanges,then density function will change too.To this end,we suppose the kernel estimation for a change point.For the other case that mean is an unknown constant,we suppose to apply empirical characteristic function to estimate the change-point location.In the two cases,we consider the consistency and strong convergence rate of estimators.Furthermore,we consider the mean shift case.If mean changes,then corresponding characteristic function will change too.To this end,we also apply empirical characteristic function to estimate change point.We obtain the similar convergence rate.Finally,we consider its application on the detection of mean shift in financial market.     

分块半相依线性回归模型的参数估计

考虑一般的分块半相依线性回归（SUR）模型及其相应的简约模型，给出简约模型下未知回归系数及其可估函数的协方差改进估计仍是分块SUR模型下相应参数的协方差改进估计的一个充要条件．     

Error estimate of eigenvalues of perturbed second-order discrete Sturm–Liouville problems

This paper is concerned with eigenvalues of perturbed second-order vector discrete Sturm–Liouville problems. By some variational properties of eigenvalues of discrete Sturm–Liouville problems, error estimates of eigenvalues of perturbed problems, sufficiently close to a given Sturm–Liouville problem, are given under a certain non-singularity condition. Perturbations of the coefficient functions of the difference equation, the weight function, and the coefficients of the boundary condition are all considered. This, together with higher-dimension involved, results in a certain complexity of the problem and difficulty of study. As a direct consequence, continuous dependence of eigenvalues on problems is obtained under the non-singularity condition. In addition, an example is presented to illustrate the necessity of the non-singularity condition.     

A novel pentaazadentate bismacrocycle cadmium complex

A novel pentaazadentate bismacrocycle was synthesized through an improved procedure of 1:1 Schiff base condensation of diformyltripyrrane with 3,4,3′,4′‐tetraamino‐biphenyl hydrochloride using Pb²⁺ as template ion, in which the condensed byproduct water was removed efficiently to make the yield over 90%. Then the bismacrocycle legend reacted with cadmium chloride to yield the title metal complex with molecular weight being 1200.4 by TOF MS and the λ_max being 766 nm.     

Approximate colored range and point enclosure queries

In this paper, we formulate two classes of problems, the colored range query problems and the colored point enclosure query problems to model multi-dimensional range and point enclosure queries in the presence of categorical information. Many of these problems are difficult to solve using traditional data structural techniques. Based on a new framework of combining sketching techniques and traditional data structures, we obtain two sets of results in solving the problems approximately and efficiently. In addition, the framework can be employed to attack other related problems by finding the appropriate summary structures.     

分光路二维剪切干涉强激光腔镜变形检测系统

介绍一种分光路二维剪切干涉光电检测系统。该系统实现了两正交方向(二维)同时进行检测与计算机自动化数据处理;采用了一系列消噪声措施和两图像相减等技术,使得波前重构中能较好地采用简单的数值积分方法;并得到了在士10μm的测量范围内,方差不超过0. 257μm和0. 05μm的灵敏度。利用该系统成功地对强激光腔镜变形过程实现了动态检测。