The Semigroup Characterizations of Nil BCI-Algebras

In this paper, some characterizations of nil BCI-algebras X are given by disscusing the adjoint semigroup of X. Moreover, the definition of generalized positive implicative BCI-algebras is introduced and some properties are obtained.AMS Subject Classification (1991): 03G25, 06F35.The subject supported by the Educational Committee of Hebei.     

GENERALIZED OPERATORS AND OPERATOR-VALUED DISTRIBUTIONS IN QUANTUM FIELD THEORY

The relation between generalized operators and operator-valued distributions is discussed so that these two viewpoints can be used alternatively to explain quantum fields.     

A NOTE OF THE SPECTRUM OF HOMOGENEOUS COMPACT OPERATORS

In this paper, we present some counterexamples which show that there is no theory on the spectrum of homogeneous compact operators which parallels the Riesz-Schauder theory on the spectrum of linear compact operators. These counterexamples also illustrate that it is impossible to study in a unified setting the Fucik spectrum of the Laplacian: -△w = au+ - bu- inΩand u = 0 on (?)Ω, as well as the spectrum of the p-Laplacian: -div(|(?)u| p-2(?)u) = λ|u|p-2u and u = 0 on (?)Ω.     

Existence for nonoscillatory solutions of higher-order nonlinear neutral difference equations

In this paper, we consider the following forced higher-order nonlinear neutral difference equation

     

空化现象的模拟准则

本文在现有理论基础上导出空化现象的模拟准则.为模拟空化现象提供依据.     

模糊(Fuzzy)映象的广义补余问题*

本文引入一类关于模糊(Fuzzy)映象的新的广义补余问题,构造出一类新的迭代算法.我们讨论这类广义补余问题解的存在性及迭代序列的收敛性.     

论理想流体与线弹性结构的耦联振动

本文对理想流体与线弹性结构的耦联振动问题作理论分析和数值分析.文中证明了耦联振动的固有频率存在并且均为正实数.将流-固耦合系统分析转化为单一结构物在真空中的自由振动分析后,频率方程中不再含有流体变元.使问题得以大大简化.给出了数值解的收敛性证明,以保证解的可靠性.文中还综合里兹法、边界元和有限元方法,提出一种分析转化后结构的混合算法.利用该算法,只需对现有结构分析程序稍作改进,就可分析那些理想流场与结构的耦合问题.一些数例说明了算法的有效性.     

Theory on the optical-phonon Raman scattering in GaAs/AlAs heterostructures

A microscopic theory of Raman scattering by optical phonons in GaAs/GaAlAs heterostructures is worked out systematically, on the basis of recent advances in our knowledge of the electronic structure and the optical-phonon modes in superlattices and quantum wells. Theories have shown that specific features of the intermediate states are of special importance for a quantitative theory. Thus, the heavy and light hole mixing effect, and the angular momentum state of the four-component excitons, can play a decisive role in determining the predominant scattering channels. Special attention has been paid to the Frolich-interaction induced scattering, which is dipole forbidden in bulk materials but allowed in multiple quantum wells owing to the barrier penetration and the hole mixing. Based on the microscopic theory, explanations are provided for such experimental facts as the asymmetry between the incoming and the outgoing resonance, the line shape of Raman spectra and the features of two-phonon Raman scattering in quantum well systems.     

First-principles electronic structure calculations with molecular dynamics made easy

The technique of quantum molecular dynamics is reviewed, and a simplified approach based on a first-principles tight-binding implementation of local density theory is discussed. Several illustrations and applications of the theory are presented. Applying it to amorphous materials, we have developed a procedure for producing amorphous Si networks with small defect concentrations. Benchmark checks are made for atomic geometries at Si(111)-(2×1) and Si(001)-(2×1), p(2×2), and c(4×2) reconstructed surfaces. A simulation of a Scanning Tunneling Microscope tip interacting with a reconstructed surface is performed, and it is shown how the tip can alter the reconstruction of the surface. Simulation of a kinked Si(001) surface step and comparison to an unkinked step are also presented.     

人血清中几种元素的ICP－AES法测定

本文研究了应用ＩＣＰ－ＡＥＳ测定人血清中Ｃａ、Ｍｇ、Ｎａ、Ｚｎ、Ｋ、Ｐ六种元素的方法。将经前处理好的人血清中加入适当的硝酸－过氧化氢混合消解液，在消解罐中经高温、高压下，使其有效地消除血清复杂基体的干扰。选用美国ＩＣＡ９０００（Ｎ＋Ｍ）型仪器的工作条件。以国家标准物质研究中心的贮备液作标准。并采用日本人血清标准和我国ＧＢＷ０９１３１牛血清标准校准仪器。