理学院讯：2018年5月17日上午，美国路易斯维尔大学徐永芝教授受邀来南昌大学理学院数学系访问交流，并在理生楼A513报告厅为数学系师生作了题为“Inverse scattering problems in stratified medium, analysis and computation”的学术报告,报告会由数学系主任汪祥教授主持。

徐永芝教授在此次报告中，主要介绍了层状介质中的逆散射问题的相关分析与计算。对于具有局部散射体的基本分层介质中的直接和逆散射问题，为了保证唯一性，需要无穷辐射条件，而均匀介质中的点源波在球面上传播，可以用Sommerfeld辐射条件来描述。而对于非局部扰动下的横向输出条件，徐教授分别介绍了分层介质中的向上传播辐射条件，侧向传播辐射条件。针对分层介质中的目标检测，徐永芝教授提出了一种有效的平行径向二分法。数值模拟实验也证明了算法的有效性。报告最后，徐永芝教授解答了部分老师和学生的提问并与在座的教师就相关问题开展了座谈与讨论。

Yongzhi Steve Xu, Professor, University of Louisville, 2004—current, Teaching and research.

Professor, University of Tennessee at Chattanooga, 2000—2004, Teaching and research.

Associate Professor, University of Tennessee at Chattanooga, 1997—2000. Teaching and research.

Assistant Professor, University of Tennessee at Chattanooga, 1995—1997, Teaching and research.

Assistant Professor, Georgetown University, 1992—1995, Teaching and research.

Postdoctorate fellow, Institute for Mathematics and its Applications, University of Minnesota, 1990—1992, Research and other activities in industrial mathematics.

Member of editorial boards

Editor-in-Chief of Applicable Analysis;Editor-in-Chief of Complex Variables and Elliptic Equations Mathematical Methods in Applied Sciences,Taiwanese Journal of Mathematics ISRN Mathematics Physics