The sizes of the Broad Line Region (BLR) of some Seyfert 1 galax-ies and nearby quasars can be determined by the reverbe......

在R和I波段对Mkn501进行了测光观测，并结合历史文献得到Mkn501在近30年间的光学、红外和射电等多个波段的光变曲线；讨论了光变与色指......