【摘要】 设λ1,λ2,…,λn是图G的特征值,则称E(G)=|λ1|+|λ2|+…+|λn|为图G的能量.用Sl1n,l2表示由两个具有唯一公共顶点u的圈Cl1和Cl2,且其余边均为u上的悬挂边的n阶双圈图.利用Sachs子图证明了在所有含有两个边不相交的圈Cl1和Cl2的n阶双圈连通图中Sl1n,l2是能量最小的.更多还原

【Abstract】 Let G=（V,E） be a graph,and λ1,λ2,…,λn are its eigenvalues,then the energy of G is defined as E（G）=｜λ1｜+｜λ2｜+…+｜λn｜.Let Sl1,l2n be the graph of order n obtained from two circuits Cl1 and Cl2with a unique common vertex u by adding some pendant edges to u.It is proved that Sl1,l2n is the minimal energy graph among all connected graphs with n vertices and n+1 edges containing two edge-disjoint circuits Cl1 and Cl2.更多还原