adj.无尘的；无灰的
Three symbols rose from the dust. 三个神谕从封尘的土中浮起。
An air curtain was designed according to the jet theory of fluid mechanics and the role and feature of air curtain to separate dust in a fully mechanized face. 根据流体力学射流理论，分析了空气幕在综采工作面隔离粉尘的作用，并根据综采工作面应用空气幕隔尘的特点，设计了空气幕。
