在Gowers与Tao等的推动下加法组合已成为一个活跃的研究领域。 非唯一分解理论是数论、组合和代数的一个热门交叉研究方向。有限Abel群上不可分极小零和序列和Davenport常数是加法组合中零和问题和非唯一分解理论的重要的研究课题，它的结构的刻画对零和问题和非唯一分解理论中的许多问题的研究是关键和重要的。 我们将深入开展这一方面的研究工作，将致力于研究那些长度仅次于Davenport常数D(G)的Abel群G 上不可分极小零和序列的结构，以及与之相关的一些经典的零和问题。本项目将致力于用组合技术、数论技巧、有限群的多项式不变量理论、 群环和表示理论等研究这一方面的问题. 所得结论将丰富对零和问题和非唯一分解理论的内容。

Due to the efforts of Gowers, Tao and etc, additive combinatorics has become an active field. Non-unique factorization theory is a popular interdisciplinary research direction. Unsplittable minimal zero-sum sequences over finite Abel groups and Davenport constants are important research topics in zero-sum problems and non-unique factorization theory of additive combinatorics, the characterization of its structure are essential for the study of many problems on zero-sum problems and non-unique factorization theory. We will make further investigation along this line, we will focus the study on the structure of unsplittable minimal zero-sum sequences whose lengths are next to the Davenport constant D(G) , where G is an Abelian group, and on the related classical problems on zero-sum problems. This project will be devoted to apply combinatorial techniques, number theory skills, polynomial invariant theory of finite groups, group rings theory and representation theory to the study of the related problems. The conclusion obtained will enrich the content of zero-sum problems and non-unique factorization theory .