Yongju Yu1, Yongjuan Yu2, Bin Li3. 1. School of Sociology and Law, Sichuan International Studies University, Chongqing, 400031, China. Electronic address: yyj002788@sisu.edu.cn. 2. School of Finance and Economics, Yangtze Normal University, Chongqing, 408100, China. Electronic address: yuyongjuan78@163.com. 3. School of Finance and Economics, Yangtze Normal University, Chongqing, 408100, China.