【摘要】 本文讨论了一个在分支值线性部分具两个零特征根且只有一个Ｊｏｒｄａｎ块，而非线性项为５次的平面向量场，得到了完整的轨线分支图。本文引入的讨论判断函数性质的方法具有一般性，因而也将适用于具更高次退化的非线性情况的研究。更多还原

【Abstract】 In this paper, we have discussed a plane vector field whose linear part has two zero eigenvalues with a Jordan block at the bifurcation point, and the nonlinear item is five powers. The whole orbit bifurcation graphs are obtined. The method with which we studied the judgement function is general, it will be useful in the research for the more degenerate vector field.更多还原