| 1 | Arnold V I . Some unsolved problems in the theory of diferential equations and mathematical physics. Russian Math Surveys, 1989, 44, 157- 171 | | 2 | Cen X , Liu C , Yang L , Zhang M . Limit cycles by perturbing quadratic isochronous centers inside piecewise polynomial differential systems. J Differ Equ, 2018, 265, 6083- 6126 | | 3 | Conti R , Sansone G . Nonlinear Differential Equations. London: Pergamon, 1964 | | 4 | Dumortier F , Li C . Perturbations from an elliptic Hamiltonian of degree four:(Ⅰ) Saddle loop and two saddle cycle. J Differ Equ, 2001, 176, 114- 157 | | 5 | Dumortier F , Li C . Perturbations from an elliptic Hamiltonian of degree four:(Ⅱ) Cuspidal loop. J Differ Equ, 2001, 175, 209- 243 | | 6 | Dumortier F , Li C . Perturbations from an elliptic Hamiltonian of degree four:(Ⅲ) Global center. J Differ Equ, 2003, 188, 473- 511 | | 7 | Dumortier F , Li C . Perturbations from an elliptic Hamiltonian of degree four:(Ⅳ) Figure eight-loop. J Differ Equ, 2003, 188, 512- 514 | | 8 | Gautier S , Gavrilov L , Iliev I D . Perturbations of quadratic centers of genus one. Discrete Contin Dyn Syst, 2009, 25, 511- 535 | | 9 | Grau M , Ma?osas F , Villadelprat J . A Chebyshev criterion for Abelian integrals. Trans Amer Math Soc, 2011, 363, 109- 129 | | 10 | Han M , Yang J , Tarta A A , Gao Y . Limit cycles near homoclinic and heteroclinic loops. J Dyn Diff Equa, 2008, 20, 923- 944 | | 11 | Iliev I D . Perturbations of quadratic centers. Bull Sci Math, 1998, 122, 107- 161 | | 12 | Li C . Abelian integrals and limit cycles. Qual Theory Dyn Syst, 2012, 1, 111- 128 | | 13 | 梁海华, 陈玉明, 岑秀丽. 一类拟齐次多项式中心的极限环分支. 数学物理学报, 2018, 38A (1): 1- 9 | | 13 | Liang H , Chen Y , Cen X . Limit cycles bifurcating from a class of quasi-homogeneous polynomial center. Acta Math Sci, 2018, 38A (1): 1- 9 | | 14 | Li C , Marde?i? P , Roussarie R . Perturbations of symmetric elliptic Hamiltonians of degree four. J Differ Equ, 2011, 231, 78- 91 | | 15 | Li C , Zhang Z . Remarks on 16th weak Hilbert problem for n=2. Nonlinearity, 2002, 15, 1975- 1992 | | 16 | Marde?i? P . Chbyshev System and the Versal Unfolding of the Cusp of Order n. Paris: Hermann, 1998 | | 17 | Pontryagin L S . On dynamic systems closed to Hamiltonian systems (in Russian). Zh Eksper Teoret Fiz, 1934, 4, 234- 238 | | 18 | Shao Y , Zhao Y . The cyclicity and period function of a class of quadratic reversible Lotka-Volterra system of genus one. J Math Anal Appl, 2011, 377, 817- 827 | | 19 | 吴奎霖, 邵仪. 亏格一双中心的二次Lotka-Volterra系统的二次扰动. 数学物理学报, 2014, 34A (5): 1275- 1286 | | 19 | Wu K , Shao Y . Quadratic perturbations of a quadratic reversible Lotka-Volterra system of genus one with two centers. Acta Math Sci, 2014, 34A (5): 1275- 1286 | | 20 | Wang J , Xiao D . On the number of limit cycles in small perturbations of a class of hyper-elliptic Hamiltonian systems with one nilpotent saddle. J Differ Equ, 2011, 250, 2227- 2243 | | 21 | Wang J , Xiao D. Han M . The number of zerosof Abelian integrals for a hyperelliptic Hamiltonian systems with degenerated polycycle. Int J Bifurcation Chaos, 23013, 23, 1350047 | | 22 | Xiao D . Bifurcations on a five-parameter family of planar vector field. J Dynam Differ Equ, 2008, 20, 961- 980 | | 23 | Xiao D , Zhang Z . On the uniqueness and nonexistence of limit cycles for predator-prey systems. Nonlinearity, 2003, 16, 1185- 1201 | | 24 | Yang J , Zhou L . Limit cycle bifurcations in a kind of perturbed Liénard system. Nonlinear Dyn, 2016, 85, 1695- 1704 | | 25 | ?oladek H . Quadratic systems with centers and their perturbations. J Differ Equ, 1994, 109, 223- 273 |
|
),Chunxiang A*(