The Homological Properties Related To Weak Injectivity Of Modules And Complexes

In this paper,we first introduce the concept of SG weak injective modules,dis-cuss the properties of these modules,and prove that Gorenstein weak injective mod-ules are the direct summands of SG weak injective modules.Secondly,introduce the concept of SG weak flat modules,and give the connection between SG weak flat modules and SG weak injective modules over the coherent ring.Finally,introduce the definition of (?)-injective complexes,and discuss the structure of (?)-injective complexes.