1. Professor, School of Economics and Management, Tianjin Chengjian Univ., Tianjin 300384, China.
2. School of Economics and Management, Tianjin Chengjian Univ., Tianjin 300384, China.
3. Assistant Professor, School of Economics and Management, Tianjin Chengjian Univ., Tianjin 300384, China (corresponding author).