P－正则半群的双序集

本文刻划了双序集Ｅ为某Ｐ－正则半群的幂等元双序集的充要条件．所得定理不仅推广了Ｄ．Ｅａｓｄｏｗｎ关于带的双序集的结论，而且导出了正则＊－半群的幂等元双序集的一个刻划．进而还对Ｐ－正则半群的若干特殊情形及向非正则半群的推广进行了讨论．     

On Weak Regular ^＊-semigroups

In this paper, a special kind of partial algebras called projective partial groupoids is defined.It is proved that the inverse image of all projections of a fundamental weak regular ^*-semigroup under the homomorphism induced by the maximum idempotent-separating congruence of a weak regular ^*-semigroup has a projective partial groupoid structure. Moreover, a weak regular ^*-product which connects a fundamental weak regular ^*-semigroup with corresponding projective partial groupoid is defined and characterized. It is finally proved that every weak regular ^*-product is in fact a weak regular ^*-semigroup and any weak regular ^*-semigroup is constructed in this way.     

Stability of <Emphasis Type="Italic">C</Emphasis>-regularized Semigroups

Let T = (T(t))t≥0 be a bounded C-regularized semigroup generated by A on a Banach space X and R(C) be dense in X. We show that if there is a dense subspace Y of X such that for every x ∈ Y, σu(A, Cx), the set of all points λ ∈ iR to which (λ - A)^-1 Cx can not be extended holomorphically, is at most countable and σr(A) N iR = Ф, then T is stable. A stability result for the case of R(C) being non-dense is also given. Our results generalize the work on the stability of strongly continuous senfigroups.     

Non-linear Semigroup of a Class of Abstract Semilinear Functional Differential Equations with a Non-Dense Domain

In this work, we are concerned with a general class of abstract semilinear autonomous functional differential equations with a non-dense domain on a Banach space. Our objective is to study, using the Crandall-Liggett approach, the solutions as a semigroup of non-linear operators.     

Weak Uniform Normal Structure and Fixed Points of Asymptotically Regular Semigroups

Let X be a Banach space with a weak uniform normal structure and C a non–empty convexweakly compact subset of X. Under some suitable restriction, we prove that every asymptoticallyregular semigroup T = {T(t) : t ∈¸ S} of selfmappings on C satisfying

${\mathop {\lim \inf }\limits_{S \mathrel\backepsilon t \to \infty } }{\left| {{\left\| {T(t)} \right\|}} \right|} < {\text{WCS}}(X)$

has a common fixed point, where WCS(X) is the weakly convergent sequence coefficient of X, and\({\left| {{\left\| {T(t)} \right\|}} \right|}\) is the exact Lipschitz constant of T(t).     

Nonlinear Boundary Stabilization of Nonuniform Timoshenko Beam

In this paper, the stabilization problem of nonuniform Timoshenko beam by some nonlinear boundary feedback controls is considered. By virtue of nonlinear semigroup theory, energy-perturbed approach and exponential multiplier method, it is shown that the vibration of the beam under the proposed control actiondecays exponentially or in negative power of time t as t→∞.     

偏最小二乘火焰原子吸收光谱法同时测定汞和钴

本文研究了偏最小二乘原子吸收光谱法同时测定Hg和Co的方法,校正中Co253.649nm对Hg 253.652nm的吸收红重叠干扰,用Hg空心阴极灯同时一合成样中的Hg和Co,方法快速、简单、准确,结果令人满意。     

乘法一口清训练软件的开发与研究

随着教学现代化水平的不断提高，电脑在学校教学中已得到广泛应用。同样在珠心算教学与训练过程中，我们也要充分利用好这一现代化教学资源。最近笔者根据乘法一口清训练的特点．开发了一款相应的训练软件。该软件发挥了电脑诸多方面的优势，大大提高了乘法一口清的训练效果。下面介绍一下该软件及在乘法一口清训练中所发挥的优势。     

乘法公式与根与系数关系的互证

在七年级学过多项式的乘法公式后,常会出现如下的题目:问题1已知实数x满足x2+x-1=0,求x2+1/x2的值?可以这样解:     

基于DEA改进前沿面的输入拥塞分析

输入拥塞分析为投入产出分析提供了另一种视角，即通过减少冗余输入以增加输出。当前，对生产单位进行输入拥塞分析的主要方法是基于数据包络分析(DEA)模型的BCSW模型。BCSW模型的基本思想是将被评价单位与DEA前沿面上的有效率单位进行比较从而得出输入拥塞的值。但该方法忽略了DEA前沿面的数据敏感性问题，即前沿面上单位发生极小变动会导致评价结果的巨大改变，导致分析结果缺乏稳健性。本文提出了一种启发式方法，从改进DEA前沿面的角度出发，通过在误差范围内找到最佳前沿面，使输入拥塞分析结果更加合理。方法的提出从DEA前沿面的数据敏感性问题的原因出发，利用最小二乘法基本思想确定DEA最佳前沿面所需具备的性质。之后在该性质下，利用超效率DEA模型的思想和方法，解决DEA前沿面存在的问题，确定了该启发式方法。最后，本文在该方法所确定的最佳前沿面的基础上，利用BCSW模型进行输入拥塞分析，在实例数据上取得了相对于原始BCSW模型更合理也更具解释性的结果，证实了利用输入拥塞分析时，DEA前沿面确实存在的问题以及解决该问题对输入拥塞分析方法的改进作用。