heat transfer by free convection是什么意思

用法例句

The underlying abnormal mantle heat gave rise to the free thermal convection, which in turn caused the heat to be lossed.

笔者借以热力学的自由热对流原理来加以论述:攀西巨厚的火山岩体在下覆异常地幔热作用下,发生自由热对流,引起热量散失,使地壳沉降与隆起不均衡,生成地堑地垒的格局。