## 蔡建生教授学术报告

$H=(X,C,D)$, the partial mixed hypergraph $H=(X,C,\emptyset)$, also denoted by $H_{c}=(X,C)$ is called a $C$-hypergraph. In this paper, we solve an open problem posed by Voloshin concerning the maximum number of hyperedges of an $r$-uniform $C$-hypergraph with given $\overline{\chi}(H)$.