研究了单圈图的无号拉普拉斯谱半径,给出了具有固定围长的单圈图的无号拉普拉斯谱半径最大的图.
This paper studies the signless Laplacian spectral radius of unicyclic graph.Unicyclic graphs of fixed order and girth with maximal signless Laplacian spectral radius are determined.