作者: Giancarlo Benettin , Poul Hjorth , Paolo Sempio
关键词: Heat capacity 、 Metastability 、 Degrees of freedom (physics and chemistry) 、 Equipartition theorem 、 Adiabatic invariant 、 Kinetic theory of gases 、 Scale (ratio) 、 Physics 、 Classical mechanics 、 Diatomic molecule
摘要: Around 1900, J. H. Jeans suggested that the “abnormal” specific heats observed in diatomic gases, specifically lack of contribution to heat capacity from internal vibrational degrees freedom, apparent violation equipartition theorem, might be caused by large separation between time scale for vibration and associated with a typical binary collision gas. We consider here simple 1D model show how, when these scales are well separated, collisional dynamics is constrained many- particle adiabatic invariant. The effect energy exchanges betgween translational freedom slowed down an exponential factor (as conjectured). A metastable situation thus occurs, which fast effectively do not contribute heat. Hence, “freezing out” could principle explained terms classical mechanics. discuss phenomenon analytically, on basis approximation introduced Landau Teller (1936) related phenomenon, estimate evolution statistical equilibrium. theoretical analysis supported numerical examples.