The piston is a cylindrical shaped hollow part that moves up and down inside the engine cylinder.

活塞是一个中空的圆柱体形状部件，其在发动机气缸里做上下往复运动。

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The piston is essentially a cylindrical plug that moves up and down in the engine cylinder.

实质上活塞是一个在气缸中上下移动的圆筒状的塞子。

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Now place the piston assembly on a flat, firm surface with diaphragm facing up as shown in Figure 9.

现在将活塞总成放在平整稳定的表面上，如图9所示让隔膜面朝上。

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And so what happens when we remove these stops is that the piston slams up against the next pair of stops.

把挡板移开后活塞会,向上移动直道第二个挡板处。

麻省理工公开课 - 热力学与动力学课程节选

So we remove the stops, and the piston moves up, and now we remove one of these weights.

我们移走挡板，活塞向上移动，移走一个重物。

麻省理工公开课 - 热力学与动力学课程节选

So, the piston moves up again, one weight.

活塞再次上升。

麻省理工公开课 - 热力学与动力学课程节选

Conventional four-stroke engines produce power by moving a piston up and down using rapid explosions of fuel and air in a cylindrical chamber.

FORBES: How to get 51mpg from an engine the size of a large turkey.

Its Variable Compression Engine can alter its compression ratio (the volume in a cylinder when the piston is up compared with the volume when it is down) from 14-1 to 8-1, depending on the circumstances.

ECONOMIST: Fuel economy

This may surprise nonpilots, but cranking up airplane engines--whether piston, turboprop or jet--has always been multistepped.

FORBES: Flying Eclipse's Pocket Jet