The dynamic loads of engine in tractor-trailer unit are classified into four kinds with frequency structure.

拖拉机挂车机组工作时的动态载荷按其频率结构可分成四类。

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Air circulation carries product heat and the heat which penetrates the walls, floors, and ceiling of the trailer to the refrigeration unit where it can be removed.

空气在循环过程中会带走农产品本身的热量，也会带走那些从门、地板和拖车的顶部渗透进来的热量。

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The Prime Power Unit (PPU) is an air- and highway-transportable, trailer-mounted 1.3MW (megawatt) Generator Set, a key component of the Terminal High Altitude Air Defense (THAAD) system.

主动力单元（PPU）是一种可搭载空中和公路运输，拖车式1.3MW （兆瓦）发电机组，这也是终端高空防御系统（THAAD）的关键组成部分。

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Mr Homer had left the handbrake off as he went to couple a tractor unit to the trailer in a sloped bay.

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The front and rear cabs (5) are steered by hydraulic rams and a drive unit links the two halves so the rear trailer can be steered independently and is not simply dragged behind the front unit.

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One WindTamer customer is the U.S. Army, which purchased last year a mobile trailer-mounted turbine and renewable energy storage unit containing the Power on Demand system that the military would be able to move around even in battle zones.

FORBES: Power Opportunity for GE, et al: How To Store Wind/Solar Renewable Energy