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1、张会生湘潭大学硕士学位论文响。此外,通过系统地研究石墨带和纳米碳管的热导率我们发现ZGNR的边界有利于声子的传输,而AGNR的边界不利于声子传输。这一观点与我们普遍认为的边界不利于声子传输这一观点相违背。这对我们更好的理解声子在石墨带和纳米碳管上的传输机制有很大的帮助。第五章中,我们对本论文进行了总结,并对低维纳米材料的热输运性质做了预测以及展望。关键字:石墨烯、分子动力学、反量子点、碳纳米管II张会生湘潭大学硕士学位论文AbstractIn2004,agroupofphysicistsofMan
2、chesterUniversity,ledbyAndreGeimandKostyaNovoselovusedthree-dimensionalgraphitefortheirexperimentandextractedasinglesheetofgrpahite,i.e.graphene.Aswellknown,grapheneisthefirsttwo-dimensionalallotropeofcarbon.Withthedevelopmentofnanotechnology,graphene
3、canalsobeobtainedbyexpitaxialgrowthonSiC.Asanovelmaterial,graphenehasextremelyhighcarriermobility,outstandingballistictransportproperty,andgiantSeebeckcoefficient.Alltheseindicatethatgrapheneandgraphenenanoribbon(GNR)canbeidealcandidatesfornanoelectro
4、nicsandthermoelectricmaterials.However,theZTcoefficientofgrapheneisverylowbecauseofthehightthermalconductivityofgraphene.Hence,howtoefficientlyreducethethermalconductivityofgrapheneandkeeptheelectricconductivityandSeebeckcoefficientnearlyunchangedisan
5、importantissueforus.Untilnow,thethermaltransportmechanismhasnotbeenwellexplored.Inchapterone,wefirstintroducethemainpropertiesoflowdimensionalnanomaterials,andthenweintroducethesignificanceofinvestigatingthermalconductivityoflowdimensionalnanomaterial
6、s.Furthermore,theexcellentthermalpropertiesofgrapheneandcarbonnanotubesarealsoshown.Finally,weoutlinetheresearchcontentsofthisthesis.Inchaptertwo,weintroducethemoleculardynamicsmethod.Byemployingthemoleculardynamicsmethod,wecalculatetheheatflow,temper
7、atureandthermalconductivityofnanosystems.Inchapterthree,wemanipulatethermalconductivityoflow-dimentionalnanosystemsbyintroducingperiodicantidotandC60molecule.First,thethermalconductivityofperfectGNRsandanti-dottedGNRsisinvestigated.Inordertoreducethet
8、hermalconductivity,variouskindsofantidotsareperiodicallymadeintheGNRs.WefindthatthethermalconductivityofGNRsisdramaticallyreducedbyintroducingantidots,especiallybysquareantidots.DifferentfromthelengthdependenceofthermalconductivityofperfectGNR