Zhenhua Chai(柴振华), Ph.D. Professor, School of Mathematics and Statistics, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Hongshan District, Wuhan, China Email: hustczh@mail.hust.edu.cn ; hustczh@126.com ResearcherID: http://www.researcherid.com/rid/ ...