中文摘要：

双圈图是指顶点数等于边数减1的连通图,Harary指数是指图中所有顶点对的距离倒数之和.基于此,主要研究了具有k个悬挂点且两个圈只有一个交点的n阶双圈图有极大Harary指数的图类.

英文摘要：

Bicyclic graphs are connected graphs in which the number of vertices equals the number of edges minus one.The Harary index is defined as the sum of reciprocals of distances between all pairs of vertices of a graph.The graphs with the largest Harary index among bicyclic graphs（only one vertex in two cycles）on n vertices and k pendent vertices are characterized.