高阶特征线性及其与semi-Lagrangian方法的比较

特征线性与semi-Lagrangian方法都是处理流体方程时间离散的两种有效的方法．它们比经典的半隐格式，如Backward-Euler／Adams-Bashforth方法有更好的稳定性．本提出一种基于高阶空间离散的特征线法，通过稳定性，精度和计算复杂性与semi-Lagrangian方法进行比较，分析了高阶特征线法的有效性和适用性，并从数值试验上对分析结果进行验证．     

Theoretical Analysis of Characteristics of GaxInl—x NyAsl—y／GaAs Quantum Well Lasers with Different Intermediate Layers

Based on the band anticrossing model, the effects of the strain-compensated layer and the strain-mediated layero n the band structure, gain and differential gain of GalnNAs/GaAs quantum well lasers have been investigated. The results show that the GaNAs barrier has a disadvantage in increasing the density of states in the conduction band. Meanwhile, the multilayer quantum wells need higher transparency carrier density than the GalnNAs/GaAs single quantum well with the same wavelength. However, they help to suppress the degradation of the differential gain. The calculation also shows that from the viewpoint of band structure, the strain-compensated structure and the strain-mediated structure have similar features.     

高应变率下U-Nb合金的断裂组织特征

利用内部爆炸加载方法对U-Nb合金进行爆破试验，对爆破试验产生的破片进行回收，并对U-Nb合金破片进行一些微观检测分析，从而初步研究在爆炸加载下U-Nb合金的微观断裂机制。     

Viscosity Characteristic in Metallic Melts with Medium／Short-Range Order Structures

Viscosities and liquid structure of alloys Cu75Al25, Cu87Sn13 and Al-12.5%Si and pure metals Cu and Sn are investigated by using torsional oscillation viscometry and high temperature x-ray diffractometry. The viscosities of pure metals and eutectic alloy melts along with the short-range order structure are found to follow the Arrhenius law in a wide range of temperature above the liquidus. The breakpoints in Arrhenius plots emerge when the structures of alloy melts are transformed from the medium-range order structure to the short-range order structure. It has been found that the change of the viscosity of the metallic alloys is a characteristic of microstructure transformation in the related melts.     

非线性控制系统的最小实现

对于那些由代数微分方程描述的具有输入输出关系的非线性控制系统，本文采用两种方法讨论了其最小实现问题：一种方法是直接计算系统的特征列；另一种方法则采用了本原元定理．两种方法给出的最小实现所需的状态变量最小数目是相等的．文中的大量代数与微分运算则可利用数学机械化来完成     

试论嫉妒的指向性

本着重探讨嫉妒的指向性特征、嫉妒指向性产生的条件及其特点。     

线性常微分方程组解的特征数的估计

复数域上线性系统ｘ＝Ａ（ｔ）ｘ，当Ａ（ｔ）＝（ａｉｊ（ｔ））ｎ×ｎ具有（ｎ，Ｎ，ｒ） 差异性质且ｒｎ时，解的特征数ｊ有估计λｊ－ｌｉｍｔ→∞１ｔ∫ｔｔ０Ｒｅａｊ（τ）ｄτｎ－１ｒ＋１－ｎｌｉｍｔ→∞１ｔ∫ｔｔ０Ａ（τ）ｄτ，ｊ＝１，２，…，ｎ，其中Ａ（ｔ）＝ｍａｘ｛｜ａｉｊ（ｔ）｜：ｉ，ｊ＝１，２，…，ｎ，ｉ≠ｊ．｝     

特征向量法建模与理论

本文从矩阵理论的角度，介绍特征向量法(亦称特征根法)建模过程中所遇到的理论问题。     

血液的光学性质研究

本文用辐射输运理论方法去计算红细胞的光学特征量,并在此基础上提出检测血细胞数密度的理论实验方案,其结果与传统的方法一致。本文为开发一种血球数自动检测仪提供了理论基础和仪器结构原型。     

理想非线性单组分色谱模型理论解与实验的比较

用气相色谱的分析方法研究了理想非线性单组分不同温度下的流出曲线，用＂特征点＂法回归出了各组分的物理常数Ｇ和ｂ，代入理论模型公式，并与实验结果进行子比较。