简介:2003年,瑞典皇家科学院决定将该年度的诺贝尔物理学奖颁给AlexeiA.Abrikosov,VitalyL.Ginzburg和AnthonyJ.Leggett,以表彰他们对超导和超流理论开创性的贡献。
简介:Theground-stateandthermodynamicpropertiesofquantummixed-spinchainsof1/2-1/2-1-1and3/2-3/2-1-1areinvestigatedbyaquantumMonteCarlosimulationwiththeloop-clusteralgorithm.For1/2-1/2-1-1chain,wefindithastwophasesseparatedbyanenergy-gapvanishingpointintheground-state.For3/2-3/2-1-1chain,thenumericalresultsshowtwoenergy-gapvanishingpointsisolatedbydifferentphasesinitsground-state.Ourcalculationsindicatethatallthesegroundstatephasescanbeunderstoodbymeansofvalence-bond-solidpicture,andthethermodynamicbehavioratfinitetemperaturesiscontinuousasafunctionofparameterα=J2/J1.
简介:Thedipole-length,velocityandaecelerationabsorptionoscillatorstrengthsforthe1s^22p-ls^2nd(3_
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简介:ConsideringthatKBe2BO3F2(KBBF)isanoutstandingdeepultravioletcrystalwhichcangeneratetheshortestwavelengthsinsecondharmonicgenerationandsum-frequencygeneration,wereportthedeterminationofthenonlinearopticalcoefficientsoftheKBBFcrystal.Thed11coefficientwasdeterminedtobe0.49pm/VbytheMakerfringesmethodatthewavelength1064nm,whichisinagreementwellwiththetheoreticalvalue.
简介:Asimplemethodisappliedtocalculatingtheisotopeshifts(ISs)on5S1/2→4D3/2,5/2transitionsof87,88Sr+.FirstwehavecalculatedtheISsoflowertransitionsonaseriesofalkali-likesystemssuchasB2+,Ca+andBa+,whichareinagreementwithotherworks.ThentheISson5S1/2→4D3/2,5/2transitionsof87,88Sr+,whichareusefultostudytheSr+opticalfrequencystandard,areevaluated.
简介:HL-2AisthefirsttokamakwithdivertorinChina.TheobjectivesofHL-2Aaretoproducemoreadaptabledivertorconfigurationstostudyenergyexhaustandimpuritycontrol,andtostudyenhancedcoreplasmaconfinementbyprofilecontrolandmoderateplasmashaping.HL-2Ahaswelloptimizedoperationalflexibilityandexcellentaccessi-bilityforthediagnosticsystemstofacilitatevariousplasmaexperiments.
简介:Weperformfirst-principlecalculationsforthestudyoftheorthorhombicRb2Cd2(SO4)3structure.Electronicenergybands,totalandpartialdensitiesofstatesarereportedandanalysed.Itisfoundthatoxygenatomic2pelectronsstronglyhybridizewithRb/orCd4dandS2pstates,resultingintwo-typeionicgroupswithweakcouplings.Itisshownthatmacroscopicdomainwallsoriginatefromsuchweak-couplingionicgroups,arisingatthecellboundaries.Theasymmetriccationbonds(Rb-OandCd-O)andthesubsequentrotationsoftheS04tetrahedracanleadtothedrivingforceoftheferroelectricbehaviour.Thepredictedpyroelectriccurrenteffectsareobservedexperimentallyintheferroelectricphase.
简介:研究了YBaCu3O6~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2Cu3O6~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高
简介:HL-2AisanewdivertortokamakunderconstructionatSouthwesternInstituteofPhysics(SWIP),Chengdu,China,basedontheexperiencefromHL-1andHL-1M.HListheshorttermofaChinesewordthatmeans"ToroidalCurrentDevice".ThemainobjectivesofHL-2Aaretoproducemoreadaptabledivertorconfigurationstostudyenergyexhaustandimpuritycontrol(thefirstdivertortokamakplasmainChina),andtostudyenhancedplasmaconfinementbyprofilecontrolandmoderateplasmashaping.
简介:Atokamakplasmadischargeinvolvesaseriesofcomplexandconcertedactionsconductedbyitscontrolsystem.TheHL-2Acontrolsystemcanbedividedintotwopartst,themachinecontrolsystemandthedischargecontrolsystem.Themachinecontrolsystem,whichconsistsofindustrialPC(IPC),configuresandoperatesthetokamak'svarioustechnicalsubsystems.Timingsys-temisintegratedintomachinecontrolsystemgivingabsolutetimeforallsubsystems.Thedischargecontrolsystem,
简介:Run2atFermilabbeganinMarch,2001,CDFwillcollectdataatamaximumrateof20MByte/secduringtherun.Theofflinereconstructionofthisdatamustkeepupwiththedatatakingrate.ThisreconstructionoccursonalargePCfarm,whichmusthavethecapacityforquasi-realtimedatareconstruction,forreprocessingofsomedataandforgenerationandprocessingofMonteCarlosamples.Inthispaerwewillgivethedesignrequirementsofrthefarm,describethehardwareandsoftwaredesignusedtomeetthoserequirements,describetheearlyexperienceswithRun2dataprocessing,anddiscussfutureprospectsforthefarm,includingsomeideasaboutRun2bprocessing.