1Xiao Lin SUN,Gut Lan ZHANG,Guo Qing TANG,Wen Ju CHEN,Guang Yan HONG,Hong Peng YOU(Optical Information Science Laboratory, Institute of Modern Optics, Nankai University, Tianjin,300071)(Changchun Institute of Applied Chemistry, Chinese Academy of Scien.Photochromism in CaS:Sm[J].Chinese Chemical Letters,1999,10(2):185-186.