本文研究了在冰态水溶液体系中γ-引发胸腺嘧啶的二聚作用机理。从二聚作用的动力学历程的研究中,我们发现当胸腺嘧啶的浓度较低时,属于胸腺嘧啶的激发三重态机理,而当胸腺嘧啶浓度较高时,则由胸腺嘧啶的激发三重态和胸腺嘧啶的激发聚集态两种机理生成以环丁烷型连结的胸腺嘧啶二聚体。本文给出了一些二聚作用的动力学参数,并讨论了形成胸腺嘧啶激发态的来源。 In this paper, the mechanism of γ-induced thymidine dimerization in an ice-cold aqueous system was studied. From the kinetic study of dimerization, we found that when the concentration of thymine is low, it belongs to the excitation triplet mechanism of thymine, while when the thymine concentration is high, it is caused by the thymidine excitation triplet state and Two mechanisms of thymidine-stimulated aggregation generate thymine dimers linked with cyclobutane. In this paper, some kinetic parameters of dimerization are given, and the origin of the thymidine excited state is discussed.