次平面 meaning in English
secondary flat
Examples
- In the first part , hilbert ' s 16th problem and the studies on it are introduced , and the results of zq - equivariant vector fields of degree 5 ( q = 2 , 3 , 5 , 6 ) are given . in the second part , the definitions of zq - equivariant vector fields and the method of detection functions are stated , and all the forms of nontrivial zq - equivariant planar polynomial vector fields of degree 7 are obtained . in the third part , a concrete numerical example of zt - equivariant perturbed planar hamiltonian system of degree 7 is constructed , and for the unperturbed vector field having maximal number of centers , its global phase portraits are analyzed ( having at least 9 topologically different phase portraits ) . then , for a given parameter group , its phase portrait trend is studied
第一部分介绍了hilbert第16问题以及它的研究与发展现状，给出了近年来利用李继彬提出的判定函数法得出的z _ q -等变( g = 2 ， 3 ， 5 ， 6 )的5次系统关于它的第二部分的研究结果；第二部分介绍了z _ q -等变向量场以及判定函数法，给出了7次平面多项式系统的所有非平凡z _ q -等变向量场具有的形式；第三部分给出了一个7次平面扰动hamilton系统，研究了它的具有最大中心数的未扰动系统( z _ 7 -等变)的全局象图，得到了9种不同的拓扑图形。 - By using the bifurcation theory of planar dynamical systems and the method of detection functions , this paper gives a configuration of limit cycles forming compound eyes . with the help of numerical analysis ( using maple ) , it is shown that there exist parameter groups such that a polynomial vector field of degree 7 has at least 49 limit cycles with z8 - symmetry
然后，利用平面动力系统的分支理论以及判定函数法，考虑z _ 8 -等变的扰动hamilton向量场，在计算机数学软件( maple )的帮助下，我们得到结论： 8次平面向量场至少有49个极限环，形成具有z _ 8 -对称性的极限环分布。