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.

摘要介绍自车上使的花鼓式发电机的演变过程，分析所石，即氧体或钕硼的性能优劣，并市场前景展望。

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的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。