A perturbation analysis for the impact torsional buckling of imperfective elastic cylindrical shells subjected to a step torque is given..The imperfection is su
Several theorems on closed(resp.open)covering properties of H-spaces areobtained which improve and generalize the corresponding results of Sperner,Klee,Alexandr
The exact analytic method was given by[1].It can be used for arbitrary variable coefficient differential equations and the solution obtained can have the second