Some Studies On Abundant Semigroups

In this thesis, we mainly study two classes of abundant semigroups. The thesis is divided into three chapters.In chapter 1, we introduce some related knowledge and list some known results.In chapter 2, we define the notion of*-normal idempotents. The struc-ture theorem for abundant semigroups with a*-normal idempotent is estab-lished. As its applications, then we establish the construction theorem of naturally ordered abundant semigroups with a biggest idempotent.In chapter 3, we investigate superabundant semigroups and give some characterizations of this class of semigroups.