Evolving process of hub dynamo which used in bicycle is presented. The performance of magnetite viz. ferrimagnetism or NdFeB is analyzed. The prospect of marketing is viewed.

摘要介绍了自行车上使用花鼓式发电机演变过程，分析了所用磁石，即氧体性能优劣，并进行了市场前景展望。

On the basis of operational principle of bladed fluid machines, a wicket-gate-free axial-flow water-power recoverer was researched and developed.

摘要基于叶片式流体机械工作原理研究开发出一种无活动导叶卧式轴流式水能回收装置。