渺位系统的AZI指标

The augmented Zagreb index of catacondensed systems

AZI指标是研究辛烷和庚烷生成热的一个有价值的预测指标,其定义为图G中所有边的权重(dudv/du+dv-2)3的总和,其中du和dv分别表示G中边uv的端点u,v的度.本文分别给出了四边形(或六边形)直链和锯齿链的AZI指标值.同时,得到了具有n个四边形(或六边形)的渺位四角系统(或六角系统)的AZI指标值的界,并确定极值对应的极图.

The augmented Zagreb index （AZI） of graph O, which is predictive of the heat of formation of octanes and heptanes, is defined as the sum of weights （dudv/du＋dv-2）3 over all edges uv of G, where d. and dvdenote the degrees of terminal vertices u and v of edge uv. In this paper, the augmented Zagreb indices of linear and zig-zag polyomino （resp. hexagonal） chains are given. Meanwhile, the bounds on the augmented Zagreb index of catacondensed polyomino （resp. hexagonal） systems with n squares （resp. hexagons） are obtained and the corresponding extremal graphs are determined.