Existence of the uniformly minimum risk equivariant estimators of parameters in a class of normal linear models

In this paper, we study the existence of the uniformly minimum risk equivariant (UMRE) estimators of parameters in a class of normal linear models, which include the normal variance components model, the growth curve model, the extended growth curve model, and the seemingly unrelated regression equations model, and so on. The necessary and sufficient conditions are given for the existence of UMRE estimators of the estimable linear functions of regression coefficients, the covariance matrixV and (trV)^α, where α > 0 is known, in the models under an affine group of transformations for quadratic losses and matrix losses, respectively. Under the (extended) growth curve model and the seemingly unrelated regression equations model, the conclusions given in literature for estimating regression coefficients can be derived by applying the general results in this paper, and the sufficient conditions for non-existence of UMRE estimators ofV and tr(V) are expanded to be necessary and sufficient conditions. In addition, the necessary and sufficient conditions that there exist UMRE estimators of parameters in the variance components model are obtained for the first time.     

关于混合型多项式Hammerstein积分方程正解迭代求法

本文给出了混合型多项式Ｈａｍｍｅｒｓｔｅｉｎ积分方程正解的迭代求法，并将所得结果应用到二阶非线性常微分方程的边值问题     

随机化交通灯的二维元胞自动机交通模型

元胞自动机交通模型以简单的规则反映交通系统中的多种因素，可以分析各种交通现象，且可在计算机上方便、高效地运作·Ｂｉｈａｍ－Ｍｉｄｄｌｅｔｏｎ－Ｌｅｖｉｎｅ模型（ＢＭＬ模型）实现了二维交通问题的元胞自动机模型的模拟研究·本文对ＢＭＬ模型作了改进，解除了该模型中关于交通灯同步变化的限制·在新模型中，每个路口的交通灯可以自由选定起始工作时间和变化节奏，于是可以更全面、准确地反映交通灯对交通系统性能的影响·本文还对新模型中出现的若干新效应作了解释·     

Banach空间中一类非线性算子Ishikawa迭代序列收敛定理

在一般的Banach空间中,研究了Ishikawa迭代序列收敛问题,去掉了通常文献中关于空间X的一致光滑或S-一致光滑的严格要求,此外,还去掉或减弱了其它某些条件。因而本质地改进了近期文献的一系列相应定理。     

Growth and optical properties of a new self-Q-switched laser crystal: Cr:Yb3Al5O12

Cr⁴⁺:YbAG (Cr⁴⁺:Yb₃Al₅O₁₂) crystal with a size up to Φ24 mm×30 mm was grown by the Czochralski method. In the absorption spectrum, there are two absorption bands at 939 and 969 nm, respectively, which are suitable for InGaAs diode laser pumping, and there is an absorption band at 1030 nm, which is suitable for passive Q-switched laser output at 1.03 μm. A broad emission spectrum from 970 to 1100 nm was exhibited from 940 nm wavelength pumping. This crystal is promising as a self-Q-switched laser crystal used for compact, efficient, highly stable, passive self-Q-switched thin chip solid-state lasers.     

中立双曲型时滞偏微分方程解振动的充要条件

本文讨论一类线性中立双曲型时滞微分方程解的振动性质，获得了其一切解振动的充要条件．     

半导体长波长异质结构材料光压谱测试探讨

本文介绍了ＩｎＰ、ＩｎＧａＡｓ、ＩｎＧａＰ、ＩｎＧａＡｓＰ等的光压港（ＰＶＳ）。并把ＩｎＧａＡｓＰ（在特定组份下）的ＰＶＳ与ＦＦＴ—ＰＬ谱进行了比较；分析和讨论了ＰＶＳ测试的局限性和复杂性；指出了对多层异质结构材料，只有把器件结构、外延工艺、ＥＣＶ测试等结合起来，才可能正确地理解ＰＶＳ给出的测试结果。     

基于"替换法"的汉字加、解密实现技术

文章讨论的基于“替换法”的汉字信息加、解密实现技术,改变了传统的汉字加密结果,使加密后的密文仍是可以识别和再利用的汉字,发送者可以在任何可编辑汉字的通讯设备上发送和接收密文,确保中文信息传输过程中的安全性。加、解密算法实现的代码语言为VFP6.0。     

激发态分子内质子转移分子2－（2′－羟基苯基）间氮杂氧茚“染料”激光特性的实验和理论研究

报道了以Ｎ２激光为泵浦光源，获得激发态分子内质子转移（ＥＳＩＰＴ）分子ＨＢＯ的激光输出现象。其激光转换效率约为１７％，调谐范围为４９５～５４０ｎｍ，最强的输出波长在５１０ｎｍ。以ＨＢＯ的激发态分子内质子转移的光物理和光化学过程为基础，建立了ＨＢＯ产生激光的动态模型，数值模拟了在宽带和窄带情况下激光输出的光谱特性和时间特性，理论计算值与实验观测值很好相符，同时证实了激发态分子内质子转移分子的激光脉冲宽度依赖于激发态分子内质子转移分子的酮式异构体的基态Ｓ′０的寿命