1. Department of Mathematics; Foshan University; Foshan 528000 People's Republic of China
2. Department of Scientific Computing and Computer Applications; Sun Yat-Sen University; Guangzhou 510275 People's Republic of China
3. Department of Applied Mechanics and Engineering; Sun Yat-Sen University; Guangzhou 510275 People's Republic of China
4. Department of Mechanics and Engineering; Sun Yat-Sen University; Guangzhou 510275 People's Republic of China