1. Postdoctoral, Dept. of Economics and Management, North China Electric Power Univ., Beijing 102206, PR China; Assistant Professor, Dept. of Business Administration, Nanchang Institute of Technology, Nanchang 330099, PR China.
2. Lecturer, Dept. of Business Administration, Nanchang Institute of Technology, Nanchang 330099, PR China.
3. Assistant Professor, Dept. of Economics and Management, North China Electric Power Univ., Baoding 071003, PR China (corresponding author).
4. Professor, Dept. of Economics and Management, North China Electric Power Univ., Beijing 102206, PR China.