Quasi-principally k-projective Semimodules

In this paper,we principally introduce the concept of quasiprincipally k-projective semimodules,on the basis of the theories of k-projective semimodules and quasi-principally modules,we get some good properties of quasi-principally k-projective semimodules,therefore generalize some properties of quasi-principally modules of ring and k-projective semimodules of semiring to quasi-principally k-projective semimodules of semiring.

Dual Semimodules and Relflexive Semimodules

In this paper, we definde the dual semimodule and reflexive semimodule in the category of semimodules and completely generalize the results of dual modules and reflexive modules to the dual semimodules and reflexive semimodules.

Exact Sequence and Commutative Diagrams of Semimodule Homomorphism

Throught the introduction of the concept * exact sequence,we set up several satisfied results of commutative diagrams of semimodule homomorphism.

Dual Zariski Spaces of Modules

Let R be a commutative ring with identity,M be an R-module,L(M)denote the set of all submodules of M and g■(M)\{OM}.For any submodule N of M,we set gV^(d)(N)={K∈g:K■N}and gζ^(d)(M)=(GV^(d)(N):N■L(M)).Consider χ■L(R)\{R},where L(R)is the set of all ideals of R.We set χV(I)=(J∈x:I■J)and χζ(R)={xV(I):I■L(R)}for any ideal I of R.In this paper,we investigate when,for arbitrary χ and g as above,χζ(R)and gζ^(d)(M)form a topology and a semimodule,respectively.We investigate the structure of gζ^(d)(M)in the case that it is a semimodule.

Some Homological Characterizations of Semigroups and Semirings

In this paper we characterize semirings all of whose p-injective semimodules are injective. We also classify monoids all of whose p-injective acts are injective.