Collaboration id: 973MCMNJU Collaboration name: 973-Morningside-NJU Collaboration authors: Xuefei Gong (1) (X. Gong) Yu Shang (1) (Y. Shang) Yan Wang (2) (Y. Wang) (1) Institute of Applied Mathematics, Academy of Mathematics and System Science, Chinese Academy of Sciences, 55 Zhongguancun Donglu, Beijing, 100080, China. (2) Department of Astronomy, Nanjing University, 22 Hankou Road, Nanjing, 210093, China.