微机开关电源的特点和检测方法

研究了微机中具有代表性的半桥脉宽式开关电源的电路的电路特点,提出了简捷、合理的检修方法和步骤,以及关键测试点的经验数据和波形图。     

Type-safe relaxing of schema consistency rules for flexible modelling in OODBMS

Object-oriented databases enforce behavioral schema consistency rules to guarantee type safety, i.e., that no run-time type error can occur. When the schema must evolve, some schema updates may violate these rules. In order to maintain behavioral schema consistency, traditional solutions require significant changes to the types, the type hierarchy and the code of existing methods. Such operations are very expensive in a database context. To ease schema evolution, we propose to support exceptions to the behavioral consistency rules without sacrificing type safety. The basic idea is to detect unsafe statements in a method code at compile-time and check them at run-time. The run-time check is performed by a specific clause that is automatically inserted around unsafe statements. This check clause warns the programmer of the safety problem and lets him provide exception-handling code. Schema updates can therefore be performed with only minor changes to the code of methods. Edited by Matthias Jarke, Jorge Bocca, Carlo Zaniolo. Received September 15, 1994 / Accepted September 1, 1995     

浅析太阳电池并网发电技术

本文阐述了太阳电池并网发电技术,指出了通过技术的改进,必将能提高太阳电池并网发电的稳定性以及降低太阳电池的发电成本,使得太阳电池的经济性和可应用性得到显著提高。     

改性沥青抗变形能力研究

以测力延度（温度为5℃,拉速为5 cm/min）及15℃的弹性恢复对基质沥青及其不同SBS加入量的改性沥青进行抗变形能力的评价,通过对测力延度曲线的分析,探索基质沥青及SBS改性沥青拉伸过程中的规律,研究改性沥青抗变形能力。