关于半clean群环

环$R$称为是半clean的, 是指环中的每个元素都是一个单位与一个周期元的和. clean环是半clean的. 刻画半clean群环的一般情形是不容易的. 我们的目的是考虑如下问题：若$G$ 是局部有限群或者是阶是3的循环群, 群环$RG$何时是semiclean的. clean群环上的一些已有结果被推广.     

挠理论中的相对内射模

For a hereditary torsion theory T,this paper mainly discuss properties of A-τ- injective modules,where A is a fixed left R-module.It is proved that if M is an A-τ-injective, B is a submodule of A,then 1)M is A/B-τ-injective;2)M is B-τ-injective when B isτ- dense in A.Furthermore,we show that if A_1,A_2,…,A_n are relatively injective modules, then A_1⊕A_2⊕…⊕A_n is self-τ-injective if and only if A_i is self-τ-injective for each i.     

广义线性McCoy环

称环R是右线性McCoy的,如果R[x]中非零线性多项式f（x）,g（x）满足I（x）g（x）=0,则存在非零元素r∈R使得f（x）r=0．设a是环R的自同态,通过用斜多项式环R[x;a]中的元素代替一般多项式环R[x]中的元素而引入a-线性McCoy环的概念．讨论了a-线性McCoy环的基本性质和扩张性质．     

F-本质子模与F-多余子模

本文研究了F-本质子模和F-多余子模.利用同调的方法,得到了F-本质与F-包络,F-多余与F-复盖之间的关系,另外还得到了F-本质子模,F-多余子模的相关性质,从而推广了文献[3,10]中的部分结果.     

关于γ-semiclean环

本文定义了一种新的环γ-semiclean环.环R称为γ-semiclean的是指R中的每个元素都可以写成一个正则元和一个周期元的和.本文主要利用环论的方法研究了γ-semiclean环的相关性质,推广了clean环和半-clean环的已知结果.     

关于$(m,n)$-凝聚模与预包络

In this paper, let m, n be two fixed positive integers and M be a right R-module, we define （m, n）-M-flat modules and （m, n）-coherent modules. A right R-module F is called （m, n）-M-flat if every homomorphism from an （n, m）-presented right R-module into F factors through a module in addM. A left S-module M is called an （m, n）-coherent module if MR is finitely presented, and for any （n, m）-presented right R-module K, Hom（K, M） is a finitely generated left S-module, where S = End（MR）. We mainly characterize （m, n）-coherent modules in terms of preenvelopes （which are monomorphism or epimorphism） of modules. Some properties of （m, n）-coherent rings and coherent rings are obtained as corollaries.     

相对于余挠对的维数(英文)

本文介绍了右R-模的F-维数(C-维数)以及环R上整体F-维数(C-维数).利用同调方法,给出了平坦模维数的新刻画.另外,得到了von Neumann正则环和完全环的新刻画.     

关于(m,n)-凝聚模与预包络

In this paper,let m,n be two fixed positive integers and M be a right R-module,we define (m,n)-M-flat modules and (m,n)-coherent modules.A right R-module F is called (m,n) M-flat if every homomorphism from an (n,m)-presented right R-module into F factors through a module in addM.A left S-module M is called an (m,n)-coherent module if MR is finitely presented,and for any (n,m)-presented right R-module K,Horn(K,M) is a finitely generated left S-module,where S = End(MR).We mainly characterize (m,n)-coherent modules in terms of preenvelopes (which are monomorphism or epimorphism) of modules.Some properties of (m,n)-coherent rings and coherent rings are obtained as corollaries.     

每个非奇异单左R-模均为GP-内射的环的正则性

In this paper, some new relations between GP-V′-rings and regular rings under certain special conditions have been found. It is proved that R is left self-injective regular with Soc(RR)≠0 if and only if R is a left GP-V′-ring containingan injective maximal left ideal and Soc(RR) 属于 Soc(RR). Moreover, for an MELTring R, it is shown that R is regular if and only if R is a left GP-injective left GP-V′-ring.     

GP-V'-环的von Neumann正则性

本文研究了GP-V'-环的von Neumann正则性问题.利用GW-理想和W-理想的性质及方法,得到了 GP-V'-环是(强)正则环的一些条件,推广了文献[3,6]中的相关结果.