工作流引擎在继电保护管理系统中的应用

继电保护管理系统中关键业务的应用开发离不开工作流技术的支持。针对于此,通过对系统的实际开发需求的分析,在传统的关系数据库的基础上,提出了一个适用于关键业务开发的基于关系数据库的轻量级工作流引擎的框架结构。深入讨论了采用关系数据库来设计工作流引擎的原因,并详细地给出了相关的设计原理以及具体的表示和实现方法。其原型已经应用到实际的继电保护管理系统中。实践证明,利用此工作流引擎可以显著地缩短业务的开发周期。     

Multiscale modelling of plastic flow localization in irradiated materials

The irradiation of metals by energetic particles causes significant degradation of the mechanical properties, most notably an increased yield stress and decreased ductility, often accompanied by plastic flow localization. Such effects limit the lifetime of pressure vessels in nuclear power plants, and constrain the choice of materials for fusion-based alternative energy sources. Although these phenomena have been known for many years, the underlying fundamental mechanisms and their relation to the irradiation field have not been clearly demonstrated. Here we use three-dimensional multiscale simulations of irradiated metals to reveal the mechanisms underlying plastic flow localization in defect-free channels. We observe dislocation pinning by irradiation-induced clusters of defects, subsequent unpinning as defects are absorbed by the dislocations, and cross-slip of the latter as the stress is increased. The width of the plastic flow channels is limited by the interaction among opposing dislocation dipole segments and the remaining defect clusters.