Scientists and engineers are beginning to study this ability of fishes in the hope of designing more efficient propulsion systems for ships.
科学家和工程师们开始研究鱼类的这种能力，希望能设计出更有效的船舶推进系统。
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The UO2 fuel is normally enriched with 3-5% of U235. The uranium alloy has been enriched to contain up to 90% U235, but is normally used at between 45-75% U235 enrichment in PWR for shipspropulsion.
On this foundation, a theoretical model based on system method for calculating coupled axial and torsional vibration of large ships diesel propulsion shafting is established.