《材料热力学》第10章Statistical Thermodynamics.pptx

1StatisticalThermodynamics第十章

2经典热力学－平衡态热力学TAPAVAUAHASAGA过程：W、Q状态A状态B准静态过程非准静态过程TBPBVBUBHBSBGB密度、温度、压强不均匀不能用状态函数来表示！?G标准态1.定义(体系、函数、材料性能)2.热力学定律3.热力学关系式4.热力学平衡1.热力学定义2.热力学定律4.热力学平衡3.热力学关系式统计热力学非平衡热力学材料性能

3经典热力学－平衡态热力学G温度压力单组元二组元多组元相变热力学相图热力学界面热力学关键问题：如何构造G自由能函数？G曲线随温度、压力和成分如何变化？成分

4INTRODUCTIONThermodynamicsisdividedintotwomainsubjects:ClassicalThermodynamicsStatisticalThermodynamicsClassicalThermodynamicsismacroscopicandphenomenalogicalStatisticalThermodynamicsismicroscopicQuantumbehavioroftheatomsofthematerialsStatisticalmechanicsconcepts,strategiesMathematicalmethodsconnectthemicroscopicbehaviorofmaterialswiththeirmacroscopicproperties.

5ClassicalThermodynamicsMacroscopicthermodynamicbehaviorVariouslawsofphysicsMathematicalprinciplesMeasuredpropertiesofamaterial.Thephenomenologicalapproachhastwomainshortcomings:First,itdoesnottelluswhyamaterialbehavesthewayitdoes.Forexample,whyenthalpyincreasewhenchangingcondition?ClassicalThermodynamicscannottellus!Thesecondthingwedonotgetfrommacroscopicthermo-dynamicsistheabilitytopredictfromfirstprincipleshowamaterialwillbehave.

6StatisticalThermodynamicsRelationshipbetweenClassicalandStatisticalThermodynamics:Macroscopicsystemsareonlythemanifestationofmicroscopicbehavior.Themicroscopicbehaviorgivesusalltheinformationweneedtoanalyzethemacroscopicsystembecausethemacroscopicsystembehavesinanaverageway.Microscopicstates------Quantummechanics

7StatisticalThermodynamicsBasicconceptsBoltzmannstatisticsandpartitionfunctionConnectingMacroscopicandMicroscopicThermo-dynamicsEnsemblestatistics

8StatisticalThermodynamicsBasicConcepts:ParticlesEnergyLevelsPopulationsMacrostatesMicrostatesProbabilities

9ParticlesInteractingParticlesNon-interactingParticlesBoltzmannStatisticsClassicalParticlesIdenticalindistinguish