Affiliation: | (1) Department of Applied Mathematics, Beijing University of Aeronautics and Astronautics, Beijing, 100083, China;(2) Program in Applied and Computational Mathematics, Princeton University, Fine Hall, Princeton, NJ, 08544, USA E-mail:;(3) Department of Mathematics, West Virginia University, Armstrong Hall, P. O. Box 6310, Morgantown, WV, 26506, USA E-mail: |