Site - select spectra indicate that the eu3 + in nanoparcles < wp = 7 > formed two kinds of luminescence centers with different branch ratios of 5d0 - 7fj . the ratio of varied with different excitation 用不同能量激发zns时5d0 7f0与5d0 7f1发光分支比不同,表明激发能量对两类发光中心的激发具有选择性。