Dual minus partial order

In this paper, we introduce the Dual-minus partial order, get some characterizations of the partial order, and prove that both the dual star partial order and the dual sharp partial order are Dual-minus-type partial orders. Based on the Dual-minus partial order, we introduce the Dual-minus sharp partial order and the Dual-minus star partial order, which are also Dual-minus-type partial orders. In addition, we discuss relationships among the Dual-minus sharp partial order, the D-sharp partial order and the G-sharp partial order(the Dual-minus star partial order, the D-star partial order and the P-star partial order).