【摘要】 原子键连通性指数是化学图论中比较重要的连通性指数,该指数已被广泛应用于研究烷烃的稳定性以及环烷烃的应变能等.通过对乘积图的研究,给出了直积、析取和对称差的原子键连通性指数的上界,证明了这些上界是紧的,并且刻画了极图.更多还原

【Abstract】 The atom-bond connectivity index is a relatively important connectivity index in the chemical graphs and has been applied to the study of the stability of alkanes and the strain energy of cycloalkanes.In this paper, the upper bounds for the atom-bond connectivity index of direct products, disjunction and symmetric differences of two graphs are presented.Those bounds are proven to be tight, and the extremal graphs are also characterized.更多还原