谱半径前五位的$n$阶拟树图

A connected graph G =(V, E) is called a quasi-tree graph, if there exists a vertex v_0 ∈ V(G) such that G-v_0 is a tree. Liu and Lu [Linear Algebra Appl. 428(2008) 2708-2714] determined the maximal spectral radius together with the corresponding graph among all quasi-tree graphs on n vertices. In this paper, we extend their result, and determine the second to the fifth largest spectral radii together with the corresponding graphs among all quasi-tree graphs on n vertices.     

旧工业区整合策略--以宁波市梅墟片区为例

通过对旧工业区的研究，指出我国旧工业区存在的主要问题：如用地混杂、土地利用率低、环境质量差、缺乏活力以及与城市发展不相协调等；提出应根据城市发展状况以及旧工业区在城市发展过程中所处的地位，挖掘发展潜力，整合旧工业区用地；并以梅墟工业区为例提出一系列整合措施．如：优化环境，规划控制积极面对市场，用地开发控制模式多元化等．最后将其上升到城市经营层面上,阐述其意义．