一类恰含一个公共点的双色有向图的本原指数集

The primitive exponent set of a class of two-colored digraphs with one common vertex

非负矩阵对与双色有向图可建立一一对应关系,从而可把矩阵的问题转化为图的问题进行研究.考虑一类恰含一个公共点的双色有向图,它的未着色图中包含4n个顶点,一个(3n+1)圈和一个圈,给出了本原条件和指数集,并对极图进行了刻画.

An one-to-one relationship can be established between nonnegative matrix pairs and two- colored digraph, so the problem of matrix pairs can be transformed into the problem of graph. A class of two-colored digraphs with one common arc whose uncolored, digraph has 4n vertices and consists of one （3n ＋ 1 ） -cycle and one n- cycle is considered. Some primitive conditions, the exponent sets are giv- en, and the characterizations of extremal two-colored digraphs are depicted.