; Xue, Sui-Jian] Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Grad Univ, Beijing 100049, Peoples R China
; [Ho, Luis C.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA
; [Bian, Wei-Hao] Nanjing Normal Univ, Dept Phys, Nanjing, Peoples R China
; [Bian, Wei-Hao] Nanjing Normal Univ, Inst Theoret Phys, Nanjing, Peoples R China
; [Wang, Jian-Min] Chinese Acad Sci, Theoret Phys Ctr Sci Facil, Beijing 100864, Peoples R China
We report on a systematic investigation of the H beta and Fe II emission lines in a sample of 568 quasars within z < 0.8 selected from the Sloan Digital Sky Survey. The conventional broad H beta emission line can be decomposed into two components-one with intermediate velocity width and another with very broad width. The velocity shift and equivalent width of the intermediate-width component do not correlate with those of the very broad component of H beta but its velocity shift and width do resemble Fe II. Moreover, the width of the very broad component is roughly 2.5 times that of the intermediate-width component. These characteristics strongly suggest the existence of an intermediate-line region, whose kinematics seem to be dominated by infall, located at the outer portion of the broad-line region.