The principleof hard work is the use of a particular polarity of the magnetic particles to record data.
而硬盘的工作原理是利用特定的磁粒子的极性来记录数据。
2
The paper presents the scheme of integrated protection and introduces integrated protection system based on transient current polarity comparison principle.
提出了电力系统集成保护的方案，描述了一种基于暂态电流极性比较原理的多出线集成保护系统。
3
A new type of variable magnet polarity DC generator is presented, and its working principle and design idea is described.