主讲人：李锋 临沂大学教授
时间：2026年6月12日15：00
地点：徐汇校区三号楼126室
举办单位：必威西汉姆联
主讲人介绍：李锋，临沂大学数学与统计公司教授，硕士生导师，韩国水原大学兼职博士生导师，美国《数学评论》评论员。2014年，受国家留学基金资助，赴加拿大西大略大学访学一年。在JDE,中国科学、Nonlinear analysis等杂志发表论文30余篇。主持完成国家自然科学基金3项，现主持国家自然科学基金面上项目1项。
内容介绍：In this paper, integrability of Lienard systems with a weak focus or saddle is discussed at first. The focal values is defined and a new method is given to classify the integrability conditions for an elementary focus or saddle.
As applications, two systems are investigated, integrability conditions are obtained. Lienard system with many elementary weak singular points are also discussed, the maximum number of limit cycles bifurcated from the elementary focus or saddles are obtained. A new method is given to classify the analytical integrability conditions for Lienard systems with an nilpotent focus or saddle. As applications, two systems are investigated, integrability and analytical integrability conditions are obtained.