三条路并的极值能量及一类图的能量排序

The union of three paths′extreme energy and energy ordering of a class of graphs

拟序是图能量排序中一种有效方法,基于该方法,已经得到了大量图类的极值能量排序的结果.Gutman给出了点数和为n的两条路的并的能量排序,而三条路的并的能量排序没有一个理想的结论.本文利用拟序法给出点数和为n的三条路的并的极值能量及一类图能量的排序.

Quasi-order can effectively solve many problems for extreme energy. Based on this method, many results for extreme energy ordering have been determined. Gutman has given the ordering for the union of two paths′ energy, but there is not a good conclusion for the union of three paths′ energy ordering, this paper determined the union of three paths′ extreme energy by quasi-order method and given the energy ordering of a class of graphs.