简介:Wesynthesized(Pb,Cd)Sr2(Y,Ca)Cu2O7+x,phasesuperconductor.AftersubstitutionofPbwithBi,theBiCd1212phaseshowsnosuperconductivity.AlthoughpreviousEXAFSstudyhasshownthelocalstructureenvironmentoftheCuissimilarinbothcompounds,EXAFSresultsofBiandPbheredemonstratethatσ2ofPb-Oin-planeislargerthanthatofBi-Oinplane,whereasσ^2ofPb-OapicalissmallerthanthatofBi-O,wheraseσ^2ofPb-OapicalissmallerthanthatofBi-Oapical.TheSrshellfeaturesarealsodiffernet,itappearedthatsuperconductivityneedssomedisorder.incarrierreservoirlayer,whichisduetothesubstitutionaldefectcausedbydifferentionicradii.
简介:ThetransientopticalpropertiesofnovelPbSnanoparticlescoatedwith2.6-O-diallyl-β-cyclodextrines(CDs)werestudiedbythefemtosecondpump-probetechnique.Theresultsshowthattheultrafasttransient-inducedabsorptionforthenovelcase.ComparedtothePbSnanoparticlesstabilizedwithpolyvinylalcohol(PVA),wefindthattheprocessforthenovelcaseisdifferentfromthePbS(PVA),WesuggestthattheCDssurfacemodificationcantrapholesonthesurfaceofPbSnanoparticles.ThiscaninduceanefficientchargeseparationbetweenthePbSnanoparticlesanditssurfaceandresultinanultrsafast-inducedabsorptionfornovelPbSnanoparticles.
简介:Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.
简介:IntheframeworkoftheITER,qualificationtests,thefirstChinaTFconductorsample(CNTFl)wastestedattheSULTANfacility.ThesamplewasmadeoftwoTFconductorsectionsmanufacturedfromidenticalinternalstannumstrandsprovidedbytheOxfordSuperconductingtechnologycompany(OST).Inordertoevaluatetheconductorperformance,thecurrentsharingtemperature(Tcs)wasmeasuredatspecifiedelectromagneticloadcyclingsteps.BothconductorsectionsoftheCNTFlsampleshowedidenticalperformance.Tcswas7.2Kbeforecyclingloading,and6.9Kevenafter950cycles,withoutsignificantdegradation,whichsubstantiallyexceedstheITERrequirementof5.7K.ThetestsoftheCNTFlconductorsampleshowedthattheelectromagneticcyclicloadexhibitedanegligibleeffectontheconductorperformance.Thecouplingtimeconstant8forAClosswas214msand71.52msbeforeandafterthecyclingload,respectively.Thetestresultsofthesamplearecomparedwiththestrandperformanceandparametermodelanalysis.