作者单位: | [1]Ph.D. candidate of School of Economics and Finance of Xi'an Jiaotong University and lecturer of Xi'an University of Engineering Science & Technology; Address: Mailbox 1838, Xi'an Jiaotong University, Xi'an, Shaanxi Province, P. R. China, Postcode: 710049 [2]不详, Xi'an Jiaotong University, Xi'an, Shaanxi Province, P. R. China, Postcode: 710049 |