时间序列和渐近正态性的一个结果

Brockwell和Davis在[1]中给出了时间序列和渐近正态性方面的一个结果，本文用不同的方法且在较弱的条件下，得到了同样的结论。     

Radiative Lifetimes of Doubly Ionized Terbium

Radiative lifetimes of two short-lived levels （i.e. 4f^8 （TF6）6p^1/2 （6, 1/2）11/2,13/2） in Tb Ⅲ are measured by time-resolved laser-induced fluorescence （LIE） technique with a two-step excitation process. Free Tb Ⅲ ions are produced in a laser-induced plasma. Lifetime values are evaluated with a deconvolution procedure of the timeresolved fluorescence signal with the temporal shape of second-step excitation pulse （about 1 ns）. The lifetimes of the 4f^8 （^7F6）6p^1/2 （6, 1/2）11/2 and 4f^8（^7F6）6p^1/2 （6, 1/2）13/2 levels are determined to be 1.9 （2） and 2.0 （2）ns, respectively.     

多维Lotka-Uolterra周期系统周期解的存在性及其全局吸引性

研究了m-维离散Lotka-Volterra竞争系统，并获得了该系统周期解的存在性及其全局吸引性.     

新型二硫纶·菲咯啉-5，6-二酮合铜(Ⅱ)配合物的磁性研究

报道了新合成的二氰基二硫纶·菲咯啉-5，6-二酮合铜(Ⅱ)配合物CuLL′(L=mnt^2-, 1,2-dicyano-1,2-ethylenedithiolate; L′=phen-5，6-dione, 1,10-phenanthroline-5,6-dione)的变温磁化率和电子顺磁共振波谱表征结果. 发现微晶粉体型的标题配合物CuLL′具有一定的顺磁性，形成四配位的近似于方形的结构. 探讨了这种配合物磁学特性与结构的关系.     

溶胶-凝胶法制备小颗粒(Y,Gd)BO_3∶Eu及其表征

用溶胶 凝胶方法制备了平均粒径为 1～ 2 μm的小颗粒、高发射效率的 (Y ,Gd)BO3 ∶Eu红色发射荧光体。用XRD、SEM、粒度分析和PL光谱对荧光体作了表征和研究。常规固相反应合成 (Y ,Gd)BO3 ∶Eu需在 1 2 0 0℃以上才能形成均一的固溶体。而溶胶 凝胶法制取稀土正硼酸盐 80 0℃灼烧已可形成均一的单相 (Y ,Gd)BO3 ∶Eu,在 1 1 0 0℃可得到发光亮度最高的荧光体。它的亮度是常规固相反应于 1 2 0 0℃制得的荧光体的 1 2 0 %。采用溶胶 凝胶法制取 (Y ,Gd)BO3 ∶Eu荧光体 ,可在相当宽的实验条件范围内得到小粒径、窄分布和高亮度的荧光体 ,且有良好的颗粒形貌。     

完全正矩阵的整数分解

n阶矩阵A称为完全正的,如果A有分解:A=BB^T,其中B为元素非负矩阵,B的最小可能列数称为A的分解指数.本文考察低阶双非负矩阵在整数环上的完全正分解及其分解指数.     

两个回归函数相等的Bootstrap检验

两个回归参数相等性检验一直是统计界感兴趣的问题之一．在这篇文章中，四个检验统计量被用于度量两曲线的差异，在原假设下统计量的分布采用向量数据的重复抽样来逼近，并给出了—些模拟结果．     

Spectra Analysis of a Novel Ti-Doped LiAlO2 Single Crystal

LiAlO2 single crvstals doped with Ti at concentration 0.2at.% are grown by the Czochralskl technique with dimensions φ42×55mm. Ti ions in the crystal are quadrivalence proven by comparing the absorption and fluorescence spectra of pure LiAlO2 and Ti： LiAlO2. After air and Li-rich atmosphere annealing, the absorption peaks in the range of 600-800nm disappear. We conclude that 682 and 756nm absorption peaks are attributed to the VLi and Vo absorptions, respectively： The peaks at 716nm and 798nm may stem from the VLi^＋ and absorptions. The colour-centre model can be applied to explain the experimental phenomena. Ti^4＋-doping produces more lithium vacancies in the LiAlO2 crystal. The intensities of [LiO4] and the associated bonds remain unchanged, which improves the anti-hydrolyzation and thermal stability of LiAlO2 crystals.     

具脉冲效应的时滞周期捕食与被捕食系统正周期解的存在性

本文研究一类具脉冲效应的时滞周期捕食与被捕食系统，利用重合度理论中的方法，获得该系统至少存在一个正周期解的充分条件。     

NECESSARY CONDITIONS FOR OPTIMAL CONTROLS OF SEMILINEAR ELLIPTIC VARIATIONAL INEQUALITIES INVOLVING STATE CONSTRAINT

This paper deals with maximum principle for some optimal control problem governed by some elliptic variational inequalities. Some state constraints are discussed. The basic techniques used here are based on those in [1] and a new penalty functional defined in this paper.