简介：Melt-spunribbonswhicharetheimportantrawmaterialforhot-deformedmagnetscanbepreparedbysingle-rollermelt-spinning.Inordertopreparewell-structuredribbons,themodeloftemperaturefieldforsingle-rollermelt-spinningprocesswasconstructedinthiswork.Theheatconductioninthisprocesswassimplifiedasonedimensionalheatconductionproblem.Itwasshownbymodelingthat,thetemperaturefieldinthemelt-spinningbeforesolidificationinthismodelcouldbedescribedasthisequationT(x,t)=Tmoexp[–k(x–x0)–k2αt]+T0.ThetemperatureT(x,t)ofthealloymeltsdecreasedwithincreasedpositionxandcoolingtimetexponentiallyfromthewheel-freesurfacetothewheel-sidesurface.TheconstantkdeterminedthedecreasespeedofalloytemperatureT(x,t),whichwasproportionaltotheinterfacialheattransfercoefficienthandtheinterfacialareaofheatconductionA0,butinverselyproportionaltothethermalconductivityK.x0wasthethicknessofthealloymelt.Withincreasedx0,thetemperaturedifferencebetweenwheel-freesurfaceandthewheel-sidesurfacebecamelarger,whichwouldleadtolargerdifferenceingrainsize.Inexperiments,theinfluenceofmelt-spinningprocessparametersonthetemperaturefieldmodelwasdiscussed,suchascoolingrollermaterials,wheelspeed,andsoon.Melt-spunribbonspreparedbysingle-rollermeltspinningatdifferentwheelspeedwereinvestigatedandmagneticpropertiesofdie-upsetmagnetsfrommelt-spunribbonsondifferentcoolingrollerwereanalyzed.Thevariationofgrainsizeinthedepthdirectionconsistedwithtemperaturefieldmodel.Thismodelprovideddirectionsforthepreparationofmelt-spunribbonswithuniformlydistributedfinegrains,whichwereverynecessaryforproducinghot-deformedmagnetswithhighmagneticperformance.

简介：Thesimplemodelfor4f-5dtransitionsoflanthanideionsincrystalswasextendedtodealwiththecaseoftheoctahedralcrystalfield,whereforthet2componentof5dorbitalsthespin-orbitinteractioncouldnotbeneglectedduetoincompletequenchingofthe5dorbitalangularmomentum.Theenergylevelsforthe4fN-15dconfigurationandtherelativelinestrengthsforthe4fN4fN-15dtransitionwerecalculatedindetail.Theresultwasappliedtotheinterpretationofthelow-temperature4f-5dexcitationspectrumofCs2NaYCl6∶Tb3+.

简介：Er/Ybco-dopedborate-silicateglasseswithvariousYbconcentrationswerefabricatedbyhigh-temperaturesolid-reactionmethod.Thephotoluminescencespectraaround1.55μmandthevisibleupconversionspectraweremeasured.TheradiativelifetimeofEr-4I13/2,com-paredwiththemeasuredone,wasobtainedbyJudd-Ofelttheorybasedontheabsorptionspectra.ArateequationmodelforEr/Ybco-dopedsystemhasbeenestablishedbasedonthedataobtainedfromthemeasurements,includingtheabsorptionandemissio...