模糊半群上的模糊同余及其扩张

给出模糊半群上的模糊同余的概念，并进一步研究它的一些基本代数性质。同时研究带有模糊半群上的模糊同余扩张性质(FCEPF)的半群类，得到一个半群有模糊半群上的模糊同余扩张性质、有模糊同余扩张性质(FCEP)、有同余扩张性质(CEP)三个条件是等价的。     

有弱局部单位半群的内射系

将幺半群的同调分类理论与S-系理论有机结合,借助酉系范畴中的内射对象研究了有弱左局部单位半群的特征.利用函子与S-系同态的可收缩性给出内射S-系的等价刻画;通过S-系上方程组的容许性质,建立S-系的内射性与其方程组的可解性之间的联系;通过探索内射系与其基本扩张的关系,给出所有S-系是内射的有弱左局部单位半群的特征.     

幺半群的内射类及投射类刻画

类比于一般环上模的内射类,定义了幺半群上的S-系的内射类和投射类,并利用它们刻画了几类特殊的幺半群．证明了完全内射幺半群和完全拟内射幺半群是等价的．并且证明了对于标致幺半群S,它是完全投射的当且仅当它是完全拟投射的当且仅当它上面的投射S-系构成了一个投射类．     

半群的模糊同余扩张

本文引入半群的模糊同余扩张的概念,给出了模糊同余扩张的同态性质,同时,本文研究了带有模糊同余扩张性质的半群类,证明了一个半群S有模糊同余扩张性质当且仅当S有同余扩张性质,最后进一步给出 有模糊同余张张性质的半群类的特征。     

关于序半群的N—类

本文给出了关于序半群 N—类的若干等价性质     

拟完全正则半群的同余格上的一类关系(英文)

本文讨论拟完全正则半群的具有同一超迹的两个同余构成的同余格上的关系T,证明该关系是同余格上的完备关系,其等价类为区间.并确定对于完全正则半群同余进行关于T的底运算得到的同余.     

拟完全正则半群的同余格上的一类关系(英文)北大核心CSCD

本文讨论拟完全正则半群的具有同一超迹的两个同余构成的同余格上的关系T,证明该关系是同余格上的完备关系,其等价类为区间.并确定对于完全正则半群同余进行关于T的底运算得到的同余.     

关于序半群的N—类

本给出了关于序半群N－类的若干等价性质。     

(∈,∈∨q(λ,μ))-模糊子半群

首先,给出了广义反模糊子半群和(∈,∈∨q(λ,μ))-模糊子半群的定义,并讨论了它们的等价刻画.其次,给出了(∈,∈∨q(λ,μ))-模糊子半群的基本性质:(∈,∈∨q(λ,μ))-模糊子半群的并仍是(∈,∈∨q(λ,μ))-模糊子半群,并获得了(∈,∈∨q(λ,μ))-模糊子半群在反直积运算下封闭的结论.最后,基于反扩张原理获得了(∈,∈∨q(λ,μ))-模糊子半群同态像与同态原像的相关性质。     

单的非负有序关联半群

一个负有序关联半群(S,≤,.,*)称为单的关联半群,如果S的所有滤子是{1}和S本身.对负有序关联半群是单的关联半群进行了刻画,给出了一个负的关联半群是单的关联半群的等价条件.     

The sympathetic sceptic’s guide to semigroup representations

This is an elementary introduction to the representation theory of finite semigroups. We illustrate the Clifford–Munn correspondence between the representations of a semigroup and the representations of its maximal subgroups. The emphasis throughout is on naturally occurring examples.     

半格序Clifford半群

证明了每一个半格序Clifford半群都能嵌入到其加法半群的半格序自同态半群当中;给出了同余单的半格序Clifford半群所具有的几种形式,得到了自然半格序零群是仅有的次直不可约自然半格序Clifford半群.     

具有Clifford断面的正则纯正半群

给出了具有Clifford断面的右正规纯正半群的等价刻画,得到了具有Clifford断面的正则纯正半群的次直积分解,证明了具有Clifford断面的正则纯正半群一定是正则纯正群．     

Super rpp semigroups

We study a class of special strongly rpp semigroups, namely, the class of super rpp semigroups. These super rpp semigroups are generalizations of both superabundant semigroups and Clifford semigroups within the class of rpp semigroups. In particular, we prove that a super rpp semigroup is a semilattice of D ^(l)-simple strongly rpp semigroups. Our result not only generalizes a well-known theorem of Clifford in the class of completely regular semigroups but also strengthens some structure theorems obtained by Ren-Shum for superabundant semigroups which are orthodox. Some special super rpp semigroups are considered and discussed.     

关于Clifford半群上的fuzzy同余

利用半群fuzzy同余的概念,讨论一类特殊的完全正则半群,即Clifford半群上的fuzzy同余.研究该类半群上fuzzy同余的性质.在此基础上,给出Clifford半群上fuzzy同余的性质和特征,得到Cllifford半群上fuzzy同余为fuzzy消去同余的充要条件.     

Some relations on completely regular semigroups

A semigroup S is called a Clifford semigroup if it is completely regular and inverse. In this paper, some relations related to the least Clifford semigroup congruences on completely regular semigroups are characterized. We give the relation between Y and ξ on completely regular semigroups and get that Y ^* is contained in the least Clifford congruence on completely regular semigroups generally. Further, we consider the relation Y ^*, Y, ν and ε on completely simple semigroups and completely regular semigroups. This work is supported by Leading Academic Discipline Project of Shanghai Normal University, Project Number: DZL803 and General Scientific Research Project of Shanghai Normal University, No. SK200707.     

具有中心幂等元的L-弱正则半群

本文定义了具有中心幂等元的(L)-弱正则半群,研究了这类半群的代数结构.利用半群上的右同余(L)+和左同余R+,证明了半群S是一个具有中心幂等元的(L)-弱正则半群,当且仅当S是H-左可消幺半群的强半格.这推广了Clifford半群的相应结果.     

A generalized Clifford theorem of semigroups

A U-abundant semigroup S in which every H-class of S contains an element in the set of projections U of S is said to be a U-superabundant semigroup.This is an analogue of regular semigroups which are unions of groups and an analogue of abundant semigroups which are superabundant.In 1941,Clifford proved that a semigroup is a union of groups if and only if it is a semilattice of completely simple semigroups.Several years later,Fountain generalized this result to the class of superabundant semigroups.In this p...     

具有Clifford断面的纯正半群

本文研究有Clifford断面的纯正半群.为了获得主要的结构定理，证明了纯正半群有群断面当且仅当它是矩形群;利用半格和矩形带，建立了有Clifford断面的纯正半群的结构.     

Semigroups with the ideal retraction property

In this paper we investigate the structure of semigroups with the ideal retraction property i.e., semigroups which are not simple and have the property that each ideal is a homomorphic retract of the semigroup. We present examples to show that the ideal retraction property is neither hereditary nor productive. That this property is preserved by homomorphisms is established for some classes of semigroups, but the general question remains open. The classes of semigroups investigated in this paper are separative semigroups, ideal semigroups, semilattices, cyclic semigroups, nil semigroups, and Clifford semigroups. It is established that a semigroup with zero 0 which is expressible as a direct sum of each ideal and a dual ideal (complement with 0 adjoined) has the ideal retraction property. The converse holds for ideal semigroups, and an example is presented which demonstrates that the converse does not hold in general.