具有四次曲线解的Kolmogorov三次系统极限环的存在性问题

THE EXISTENCE OF LIMIT CYCLES FOR THE KOLMOGOROV CUBIC SYSTEM WITH A QUARTIC CURVE SOLUTION

证明了具有退化四次曲线解[y-（x-1）^2]^2=0的Kolmogorov三次系统是可以存在极限环的．并举出了具体的例子．

In this paper, it is shown that the Kolmogorov cubic system with degenerate quartic curve solution [y- （x- 1）^2]^2 =0,may have limit cycles, and a concrete example is given.