应我司邀请，3月26日下午，宁波大学王小苗教授在砺志楼105作了题为《Difference matrices and their applications》的报告。相关师生聆听了此次报告，报告由曹炜老师主持。

报告中，王小苗教授主要介绍In this talk,we will present some progress on difference matrices. We complete the existence spectrum of a (G,4,1)-difference matrix over any finite abelian group G. Let D_2Hbe the generalized dihedral group of afiniteabelian group H. It is proved that a (D_2H,4,1)-difference matrix exists if and only if H is of even order and H is not isomorphic to Z₄.We showthat if G is a finite abelian group and the Sylow 2-subgroup of G is trivial or noncyclic, then a (G,5,1)-difference matrix exists except for someexceptions.报告结束后，在座的师生就相关研究问题进行了探讨和交流。

王小苗，宁波大学，教授，主要从事组合学与编码理论的研究。主持完成国家自然科学基金项目3项。在J. Combin. Theory Ser. A和IEEE Trans. Inform. Theory等国内外重要刊物上发表学术论文30余篇。