The project item of scientific research support for youth teachers of colleges and universities of Anhuiprovince (Grant No.2003jql01) and the project item of Anhui University for talent group construction.
本文刻画了如下的混合图:在添加一个环时,它恰有一个 Laplace特征值以整数增加,其它的 Laplace特征值保持不变.本文是文章[Linear Algebra and its Applications 374(2003):307-316]的一个延续性的文章.