在前人对八种变换图研究的基础上,探讨了变换后满足正则性的原图的性质,得到了如下结果:G^+++及G^---是正则图当且仅当G是正则图;G^++-和G^--+为正则图的充要条件是G为Gn、K2,n-2或K4;G^+-+和G^-+-是正则图当且仅当G为C5、K7、K2、K3,3或G0;G^-++和G^+--是正则的当且仅当G是(n-1)/2-正则图.同时还讨论了变换图的谱半径上界,并对这些上界进行了估计.
In this Paper, we study the graphs which can be transformed to regular graphs. We present the results: G^+++ and G^--- are regular if and only if G is regular; G^++- and G^--+ are regular if and only if G≌ Cn or K2,n-2 or K4; G^+-+ and G^-+- are regular if and only if G ≌ C5 or K7 or K2 or K3,3 or G0; G^-++ and G^+-- are regular if and only if G is (n-1)/2-regular. We also give some upper bounds on the spectral.radius of transformation graphs. Then we estimate these upper bounds.