TY - Chin. Phys. B A1 - Zhang Ke-Jun(张克军), Fang Jian-Hui(方建会), and Li Yan(李燕) T1 - Perturbation to Mei symmetry and Mei adiabatic invariants for discrete generalized Birkhoffian system Y1 - 2011-05-15 JF - Chinese Physics B JO - Chin. Phys. B SP - 54501 EP - 054501 VL - 20 IS - 5 UR - https://cpb.iphy.ac.cn N1 - 10.1088/1674-1056/20/5/054501 ER -