1. Beijing University of Chemical Technology, Department of Mathematics, 15 Beisanhuan East Road, ChaoYang District, Beijing 100029, China
2. Beijing Jiaotong University, School of Computer and Information Technology, 3 Shangyuancun, HaiDian District, Beijing 100044, China
3. Beijing University of Chemical Technology, College of Chemical Engineering, 15 Beisanhuan East Road, ChaoYang District, Beijing 100029, China