SANG Bo. Center Conditions and Limit Cycle Bifurcations for Two Classes of Rigid Systems[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2014,53(6):146-149.
SANG Bo. Center Conditions and Limit Cycle Bifurcations for Two Classes of Rigid Systems[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2014,53(6):146-149.DOI:
the necessary and sufficient conditions for the origin to be center are given. And the maximal number of limit cycles bifurcating from the weak focus is proved to be 3. For a class of seven order rigid systems
the necessary and sufficient conditions for the origin to be center are given. And the maximal number of limit cycles bifurcating from the weak focus is proved to be 4.