复旦大学《大学物理-热学》课件_第10、11次课.pdfVIP免费

大学物理（热学）1)MeanFreePath2)Diffusion,Thermalconductivity,andViscosity2006-10-12EquilibriumdistributionNvvvvN222212+++=dnisthenumberofmoleculesxxxvvvd+→vyvy+dvy→zzzvvvd+→in→=NnvNnviiid22Nvnvn++=222211ni⎯thenumberofmoleculesofivnearvamongNmolecules,howmanyarenearvprobabilitythatonemoleculeisnearvproportionaltodvx...()xxvvfdMeaningofdn/N()()()ddd),,(dzzyyxxzyxvvfvvfvvfNvvvn=Isotropicassumption()()()()()2222zyxzyxvvvvvfvfvf++==()()22expxxvCvf−=ThesolutionisTheprobabilityshouldbenormalized=Nnd1()3223dexpd1−==xxvvCNn−=−xxvvCdexp122()−=xxvvCdexp12212...