讲座题目： Complex bifurcations and new types of structure discovered in the Qi system

主 讲 人：李先义教授（浙江科技大学）

讲座时间：2016年7月2日（周四）上午9:30

讲座地点：钱伟长楼 201会议室

欢迎有兴趣的师生前来聆听、交流。

数学与数据科学学院

2026年6月30日

讲座内容简介：

In this talk, we revisit the Qi system and reveal its previously undiscovered complex dynamical properties. We first rigorously characterize the precise distribution of its equilibria in its total parameter space, then completely analyze the stability of all of its equilibria. Next, what's more important, we investigate its bifurcation problems concerning both the quantity of equilibria and stability boundaries, further analyzing codimension-two bifurcations between subcritical and supercritical pitchfork bifurcations as well as codimension-three Hopf bifurcations. Finally, through numerical encoding of system trajectory, we generate biparametric sweep that unveils several remarkable phenomena deserving deeper exploration, where, most significantly, we first discover in the Qi system intriguing and new types of structure: self-similar UII-shaped structure and shrimp-shaped structure.

主讲人简介：

李先义，二级教授，博士生导师，非线性分析研究所所长。发表科研论文130余篇，SCI收录84篇，EI收录30余篇，Top期刊16篇，H-因子为20；在德国出版专著一部（读硕两年，提前攻博，博士提前毕业；湖南省破格晋升副教授、破格晋升教授）。主持科研项目20余项。担任中国博士后科学基金，国家自然科学基金，“万人计划”， “双千计划”，多个省市自然科学基金，科技进步奖等的通讯评审专家与会议评审专家。担任多个国际期刊的主编、副主编、荣誉编委、编委及50余种科研期刊的审稿专家。