Let Rbe a commutative ring with identity, a an ideal of Rand Ma finitely generated R-module. In this paper, for fixed integers t and j, we study the existence of the following isomorphisms of local cohomology modules:

Let R be a commutative Noetherian ring and a be an ideal of R such that cd(a,R) −

grade(a,R) ≤ 1, where cd(a,R) is the cohomological dimension of R with respect to

a and grade(a,R) is the grade of a. We show ...