本文采用直接蒙特卡洛方法(DSMC),对三维空间内纳米尺度下氩气的导热现象进行了数值研究.研究发现:当Kn较大时,气体的导热具有明显的尺度效应,热流密度分布呈抛物线形状;由于没有考虑Kn层内分子自由程的分布情况,现有的理论预测公式高估了纳米尺度下气体的热导率;如要准确预测纳米尺度下气体的热导率,需要对预测模型中气体分子自由程进行修正.“,”The heat conduction of argon gas in 3-D nanoscale pores was studied by direct simulation Monte Carlo (DSMC) method.It was concluded that the size effect on the gas heat conduction is significant and the parabolic heat flux profile has been observed when the Knudsen number is large.The existing models overestimate the thermal conductivity of gas in nanoscale for ignoring the Knudsen layer near solid walls.In order to predict the gaseous thermal conductivity in nanoscale accurately,the mean free path of gas in existing models should be corrected.