The results showed that a conveyor belt with the excellent comprehensive performance was made on the existing equipment by using the dipped vinylon/cotton canvas instead of the all cotton canvas and adjusting the cover formula;the weight of belt decreased by 20%;the capacity increased by more than 30%;the cost decreased by 4.

A necessary and sufficient condition of atomic semigroup rings is obtained, when the rings are primelizable,and when the semigroups,in which there is a complete non-invertible generating set ,and satisfying a.