In the second chapter, we obtain the necessary and sufficient condition where the cubic kolmogorov type system is bounded if homogeneous polynomials of degree 3 are relatively prime . and we obtain there are only four behaviours of the trajectories near the equator of the bounded cubic system if the homogeneous polynomials of degree 3 are relatively prime . in the third chapter, we study the existence and nonexistence of limit cycle for a class of bounded cubic systems 第一章為引言;第二章,我們得到了齊三次項(xiàng)互素時(shí)三次kolmogorov型系統(tǒng)有界的充分必要條件及其在赤道上孤立奇點(diǎn)附近軌線(xiàn)的分布情況有且僅有四種;第三章,我們研究了一類(lèi)有界三次kolmogorov型系統(tǒng)極限環(huán)的存在性與不存在性。
In the second chapter, we obtain the necessary and sufficient condition where the cubic kolmogorov type system is bounded if homogeneous polynomials of degree 3 are relatively prime . and we obtain there are only four behaviours of the trajectories near the equator of the bounded cubic system if the homogeneous polynomials of degree 3 are relatively prime . in the third chapter, we study the existence and nonexistence of limit cycle for a class of bounded cubic systems 第一章為引言;第二章,我們得到了齊三次項(xiàng)互素時(shí)三次kolmogorov型系統(tǒng)有界的充分必要條件及其在赤道上孤立奇點(diǎn)附近軌線(xiàn)的分布情況有且僅有四種;第三章,我們研究了一類(lèi)有界三次kolmogorov型系統(tǒng)極限環(huán)的存在性與不存在性。