摘要
主要研究双圈仙人掌图零阶广义Randic指数的界.Ln表示连通的n阶双圈仙人掌图的集合.MnLn表示没有悬挂点且两圈由一条路相连的仙人掌图的集合,即n3=2,n2=n-2.Mn Ln表示两长为3的圈有唯一公共点,其余均为悬挂边,且所有悬挂边均与两圈公共点相连的仙人掌图集合,即nn-1=1,n2=4,n1=n-5.则当α<0或α>1时,图G在Mn中取得极小图,在Nn中取得极大图;当0<α<1时,图G在Nn中取得极小图,在Mn中取得极大图.
In this paper, we present the sharp bounds of the zero-order general Randic index of bicyclic cacti. Let L, denote the set of connected bicyclic cacti with n vertices. Denote by Mn Ln, the set of cacti with no pendent vertices and the two cycles are joined by a path, i. e. , n3=2, n2=n-2. Denote by N, CL, the set of cacti satisfying that the two cycles of three vertices have one common vertex and the other edges are all pendent edges, and all pendent edges join with the only common vertex of the two cycles, i. e. , nn-1=1, n2=4, n1 =n-5. When a〈0 or a 〉1, the minimal graph is in M, and the maximum graph is in N, ; when 0〈a〈1 , the minimal graph is in N,, and the maximum graph is in M.
出处
《河北北方学院学报（自然科学版）》
2010年第3期10-12,24,共4页
Journal of Hebei North University:Natural Science Edition
基金
国家自然科学基金项目(10901001)
安徽省优秀青年人才基金项目(2009SQRZ196)
安徽省优秀青年人才基金项目(2010SQRL020)
