摘要
Motivated by the connection with the genus of the corresponding link and its application on DNA polyhedral links,in this paper,we introduce a parameter s_(max)(G),which is the maximum number of circles of states of the link diagram D(G)corresponding to a plane(positive)graph G.We show that s_(max)(G)does not depend on the embedding of G and if G is a 4-edge-connected plane graph then s_(max)(G)is equal to the number of faces of G,which cover the results of S.Y.Liu and H.P.Zhang as special cases.
基金
supported by the National Natural Science Foundation of China(Nos 11271307,11171279,11101174)。
