围下 meaning in English

wai ha

Like all engines , internal - combustion power plants run most efficiently in a narrow range of torque and speeds
内燃式发电机跟所有的引擎一样，必须在很窄的扭力和转速?围下才能达到最高效率。
Its framework allows one to establish the connections between the feedback linearization method and one - step - ahead prediction horizon , but its implementation does not require on - line optimization algorithms
其架构是结合回馈线性方法及在提前一步预测?围下建立，不过执行方式是不需要线上即时最适化演算。