Key Laboratory of Urban Security and Disaster Engineering (Ministry of Education), Beijing University of Technology, Beijing, China

Mechanical Engineering and Mathematics, University of California, Santa Barbara, CA, USA

Department of Applied Physics, Autonomous University of Baja California, Mexicali, Mexico

Department of Mathematics, Indian Institute of Technology, Patna, India

Department of Mathematics, Western Kentucky University, Bowling Green, KY, USA

Dipartimento di Matematica e Informatica, University of Calabria, Cosenza, Italy

Department of Mathematics, Shanghai Normal University, Shanghai 200234, China

Department of Mathematics, Indian Institute of Technology Patna, Patna, India

Department of Aerospace Engineering, Texas A&M University, 3141 TAMU, College Station, TX 77843-3141, USA

1.London Insitute for Mathematical Sciences, Royal Institution, 2. Merton College, University of Oxford, 3. Department of Mathematics, City, University of London, 4. Nan Kai University, Tian Jin, China