中文摘要：

事务是由一组数据库操作序列组成的，具有ACID特性。然而，在大规模分布式应用环境下，传统的事务模型是不适用的。基于本地封闭世界假设，结合数据复制技术，提出一种基于本地封闭世界假设的分布式事务模型，阐述该事务模型的特点、并发控制策略，给出该事务模型的正确性证明，并用一个简化的教学管理系统说明该事务模型。

英文摘要：

A transaction consists of a serial of operations, and has ACID properties. However, in large-scale distributed applications, the traditional transaction model is not applicable. A transaction model based on local closed world assumption, as well as data replication, is proposed. Its features, concurrency control and correctness are also investigated and demonstrated. This transaction model is illustrated with a teaching management system.