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．     

图的P-正则自同态幺半群

刻划了具有Ｐ－正则自同态幺半群的二分图,讨论了字典序积图的自同态幺半群的Ｐ－正则性。     

弱P—正则半群

在本文中,我们刻画弱P－正则半群上的最大幂等分离同余,并且证明了有超C－集的弱P－正则半群S[P]是拟P－正则当且仅当它同构于WB（p)[P^*]和某个弱正则^*-半群T的织积,其中B是S[P]的半带,最后,我们获得,在一般情况下,WB(p)[P]的弱P－正则半群但不是P－正则半群的条件。     

幂等元生成的正则Г—半群

本文考虑了（Ｅ（Ｓ））－由正则Г－半群Ｓ的幂等元生成的子Г－半群，着重研究了〈Ｅ（Ｓ）〉和Ｓ之间的关系，讨论了〈Ｅ（Ｓ）〉＝Ｓ的情形。     

D—正则半群上的同余

刻划Ｄ－正则半群上的如下同余：包括在Ｄ［Ｒ］中的最大同余、最大幂等元分离同余、（最小）基本强Ｄ－同余和群同余。     

Γ—正则半群上的若干同余

本文首先给出了Γ－正则半群上的群同余刻划。然后定义了Γ－逆半群的幂等分离核正规系，证明了Γ－逆半群上的幂等分离核正规系决定一个Γ－逆半群上的等分离同余，及Γ－逆半群上的幂等分离同余核是一个等分离核正规系。     

P—正则半群上的格林关系

给出了Ｐ－正则半群上同余的格林关系的几个等价表示，从而推广了Ｊ．Ｍｅａｋｉｎ在正半群上的结果。     

关于左π—正则po—半群

本文在po-半群和半群中引起一致π－半素族的概念，并给出了左π－正则po-半群的若干刻划，这些刻划推广了N.Kehayopulu在文[1]中给出的一些结果。     

П正则半群的幂等元同余类

本文分别给出П正则半群的幂等元同余类和Пｏｒｔｈｏｄｏｘ半群［１］的幂等元同余类的П正则性刻画．其次，证明П逆半群或完全П正则半群Ｓ的幂等元同余类是Ｓ的П正则子半群．最后讨论ｏｒｔｈｏｄｏｘ半群的幂等元同合类的正则性．     

2-弱幂P(△)-半群

本文刻划了半格不可分的＞－弱幂ｐ－半群，描述了半格可分的２－弱幂ｐ－半群的结构．在此基础上，刻划了２－弱幂△－半群．     

拟正则双序集用矩形双序集的余扩张

称双序集E为双序集F用矩形双序集的余扩张,若存在满双序集态射θ：E→F,使对每个α∈F,αθ－1是E的矩形双序子集．本文讨论了拟正则双序集的这种余扩张的性质,给出了它们的结构．作为应用,证明了拟正则的硬双序集实为正则双序集．     

LRT-Biordered Sets

We give a characterization and a representation of LRT-biordered sets. IT-biordered sets form a subclass of the class of all LRT-biordered sets: they are the biordered sets of idempotents of regular semigroups with an inverse transversal.     

弱P-正则半群上的幂等元分离同余格

在本文中，弱P-正则半群上的弱P-正则，弱正规子集的概念被介绍．在弱P-正则半群上的弱P-正则，弱正规子集的若干性质被获得后，我们给出了弱P-正则半群上的幂等元分离同余格的一个刻画。     

P-正则半群的结构

本文定义了一类称之为PR-系的代数,证明了每个PR-系是一个P-正则半群, 而且每个P-正则半群可用这种方式来进行构造.     

Biordered Sets of Regular Semigroups with Inverse Transversals1

In a regular semigroup S, an inverse subsemigroup S° of S is called an inverse transversal of S if S° contains a unique inverse x° of each element x of S. An inverse transversal S° of S is called a Q-inverse transversal of S if S° is a quasi-ideal of S.If S is a regular semigroup with set of idempotents E then E is a biordered set. T.E. Hall obtained a fundamental regular semigroup T_E from the subsemigroup E which is generated by the set of idempotents of a regular semigroup. K.S.S. Nambooripad constructed a fundamental regular semigroup by a regular biordered set abstractly. In this paper, we discuss the properties of the biordered sets of regular semigroups with inverse transversals. This kind of regular biordered sets is called IT-biordered sets. We also describe the fundamental regular semigroup T_E when E is an IT-biordered set. In the sequel, we give the construction of an IT-biordered set by a left regular IT-biordered set and a right regular IT-biordered set.This project has been supported by the Provincial Natural Science Foundation of Guangdong Province, PR China     

对称正定Toeplitz方程组的多级迭代求解

二级迭代法亦称内外迭代法. 多级迭代法由多个二级迭代嵌套而成.这些方法特别适合于并行计算,同时可以理解为古典迭代法的延伸或共轭梯度法的预处理子.本文讨论了对称正定Toeplitz线性方程组多级迭代法. 首先,基于Toeplitz矩阵的结构, 我们给出了多级块Jacobi分裂,然后证明了每一级分裂均为P-正则分裂, 并证明了当每一级内迭代次数均为偶数时,迭代法的收敛性. 最后通过数值实例验证了此方法的有效性.     

A concept of variety for regular biordered sets

We define a bivariety of regular biordered sets to be a nonempty class of regular biordered sets which is closed under taking direct products, regular bimorphic images and relatively regular biordered subsets. It is then shown that there is a complete lattice morphism mapping the complete lattice of all e-varieties of regular semigroups onto the complete lattice of all bivarieties of regular biordered sets; as a corollary we prove that there is a complete lattice morphism mapping the complete lattice of all e-varieties of E-solid regular semigroups onto the complete lattice of all varieties of solid binary algebras. Examples of bivarieties include the class of all solid regular biordered sets and the class of all local semilattices. For each setX with at least two elements, we show that a bivariety contains a free object onX if and only if it consists entirely of solid regular biordered sets or it consists entirely of local semilattices. The author gratefully acknowledges the financial support of an Australian Postgraduate Research Award.