简介:Weperformfirst-principlecalculationsforthestudyoftheorthorhombicRb2Cd2(SO4)3structure.Electronicenergybands,totalandpartialdensitiesofstatesarereportedandanalysed.Itisfoundthatoxygenatomic2pelectronsstronglyhybridizewithRb/orCd4dandS2pstates,resultingintwo-typeionicgroupswithweakcouplings.Itisshownthatmacroscopicdomainwallsoriginatefromsuchweak-couplingionicgroups,arisingatthecellboundaries.Theasymmetriccationbonds(Rb-OandCd-O)andthesubsequentrotationsoftheS04tetrahedracanleadtothedrivingforceoftheferroelectricbehaviour.Thepredictedpyroelectriccurrenteffectsareobservedexperimentallyintheferroelectricphase.
简介:On △I=4 Bifurcation PhenomenaOn△I=4BifurcationPhenomena¥ZhangJingye;YangSunandMikeGuidryTheexperiments-bythenew7--raydetector...
简介:Therearemoreandmorecountriestoakeanefforttothestudiesofvanadiumalloyforfusionapplication.NIFSinJapanhasrecentlydevelopedan80kgheatV4Cr4Tialloy(NIFS-heat2)aftertheproductionofa500kgscaleV4Cr4TiinU.S.severalyearsago.PropertyevaluationofthealloyhasbeenputintoaninternationalcollaborationprogramunderthecoordinationofIEA(InternationalEnergyAgency).SWIPhasjoinedthecollabrationonthehydrogenembrittlementresistanceevaluationofthealloyt.
简介:SinceitserliestyearsofR&D[1],theGEANT4simulationtoolkithasbeendevelopedfollowingsoftwareprocessstandardswhichdictatedtheoverallevolutionoftheproject.Thecomplexityofthesoftwareinvolved,thewideareasofapplicationofthesoftwareproduct,thehugeamountofcodeandCategorycomplexity,thesizeanddistributednatureoftheCollaborationitselfareallingredientswhichinvolveandcorrelatetogetherawidevarietyofsoftwareprocesses.Althoughin"production"andavailabletothepublicsinceDecember1998,theGEANT4softwareproduct[1]includesCategoryDomainswhicharestillunderactivedevelopment.Thereforetheyrequiredifferenttreatmentalsointermsofimprovementofthedevelopmentcycle,system,testingandusersupport,ThisarticleismeanttodescribesomeofthesoftwareprocessesastheyareappliedinGEANT4forbothdevelopment,testingandmaintenanceofthesoftware.
简介:TheGAUDIsoftwareframeworkistobeusedforallevent-processingapplicationsintheLHCbexperiment.TheGEANT4toolkithasbeenintegratedintoGAUDItoformthebasisoftheLHCbsimulationprogramGAUSS.Thebenefitsofthisapproacharethatitpermitsre-useofbasicservices,suchaspersistency,interactivityanddatavisualization,aswellasphysicsalgorithmsthatwereoriginallydevelopedinthecontextofthereconstructionandanalysisprograms.FollowingtheGAUDIphilosophy,theintegrationhasbeenachievedbydevelopinganumberofserviceswithabstractinterfacesthatcanbepluggedinatrun-time.Wedescribetheoveralldesignanddetailsofthecomponentsforinterfacingthedetectorgeometry,theprimaryinteractionandtheoutputfromtrackingparticlesthroughthedetector.
简介:Geant4LowEnergyElectromagneticpackageProvidesaprecisetreatmentofelectromagneticinterationsofparticleswithmatterdowntoverylowenergies(250oVforelectronsandphotons,<1keVforhadronsandions),Itincludesaverietyofmodelsfortheelectromagneticprocessesofelectrons,photons,hadronsandions,takingintoaccountadvancefeatures,suchasshelleffectsandeffectsduetochargedependence.Thecomprehensivesetofparticletypesitcanhandle,thevarietyofmodelingapproachesandtheextendedcoverageofenergyrangemakethispackageauniquetoolamongMonteCarlocodesonthemarket,andofrelevancetoserveralexperimentaldomainsinHIEP,astroparticlephysics,spacescienceandbiomedicalstudies.
简介:本文介绍由三片集成块CS8204、WE9140A、TEA1061组成的典型电话机电路,主要分析电话机的电源供给电路、振铃电路、拨号电路和通话电路。
简介:ThegrowinginterestintheuseofGalliumArsenidssemiconductormaterialshaspresentedmanyopportunitiesfordeviceoperationalspeedimprovementsbuthasalsopresentedmanyproblemsforthedevicemaker,Anoveldeep-submicronx-raylithographyprocessforT-shapedgatepatternsusefulforhigh-electron-mobilitytransistors(HEMT)isintroducedinthiswork.InthefabricationofT-shapedgateatherrlayerresistsmethodisused.Thex-rayexposureexperimentswerefinishedbyBeijingSynchrotronRadiationFacility(BSRF)3B1Abeamline,andgoodresulthasbeenobtained.
简介:Pureandneodymium-dopedgadoliniumcalciumoxoboratecrystalsofhighqualityweregrownbytheCzochralskimethod.Theorientationofcrystalwaspreciselydetermined,andthesamplesformeasurementswereprepared.Throughsynchrotronx-raytopographyandhigh-resolutionx-raydiffractometry,thetwinstructurewasdiscovered.Somepropertiessuchasthefigureofmeritvalue,anddielectric,piezoelectric,andelasticconstantsweremeausuredalongwithadiscussionoftheanisotropyofthelaserproperties.
简介:OptimalexploitationofhadronicfinalstatesplayedakeyroleinsuccessesofallrecenthadroncolliderexperimentinHEP,andtheabilitytousehadronicfinalstateswillcontinuetobeoneofthedecisiveissuesduringtheanalysisphaseoftheLHCexperinentsMonteCarloimplementationsofhadronicshowermodelsprovidedwithGEANT4facilitatetheuseofhadronicfinalstates,andhavebeendevelopedformanyyears.Wewillgiveanoverviewonthephysicsunderlyinghadronicshowersimulation,discussingthethreebasictypesofmodelling;datadriven,parametrisationdriven,andtheorydrivenmodelling,andtheirrespectiveimplementationstatusinGEANT4.Wewillconfrontthedifferenttypesofmodellingwithavalidationsuiteforhadronicgeneratorsbasedoncross-sectionsmeasurementsfromthintargetexperiments,andexposethestrengthandweaknessesoftheindividualapproaches.