＂Nivaranaviskambin＂

Introduce　the　corresponding　concepts　of　cover　and　hull　through　Q　gets　the　properties　of τ-injective,τ-projective,τ-pisible　and　τ-copisible,discuss　the　properties　of　τ-torsion　injective　hull, τ-torsion　projective　cover,τ-torsionfree　pisible　hull　and　τ-torsionfree　copisible　cover, τ-injective　hull　E_τ(M)　is　characterized　by　using　them.

讨论τ-挠内射包,τ-挠投射盖,τ-挠自由可除包和τ-挠自由余可除盖的性质,并利用它们刻画了τ-内射包Eτ(M)。