One way to increase the efficiency of a high-bypass jet engine is to turn the fan into an open rotor, a bit like returning to propellers, but using two rings of stubby counter-rotating blades.

提高高旁通飞机引擎的方法之一就是把风扇变成开放式旋翼，有点回归于螺旋桨的味道，但要使用两圈粗短的反旋桨叶。

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A high performance electromagnetic counter-force actuator is designed for engine active vibration control system.

针对发动机振动主动控制系统设计了一种高性能电磁反力作动器。

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Calibration relationship between compressure ratio and digital counter reading can be used to evaluate the spark-ignition engine.

采用压缩比与数字计数器的对应检索校正关系来评定检查火花点燃式发动机的机械状况。

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The engine constantly throttles up and down, not only to counter the drag on the satellite from residual air molecules in near space but also to smooth the flight of the vehicle to minimise the noise in the gravity measurements.

BBC: Goce gravity mapper surfs atmosphere

But we think that runs counter to the whole spirit of openness that has made the Internet such a powerful engine for not only economic growth, but also for the generation of ideas and creativity.

WHITEHOUSE: Your Interview with the President