简介:Inthisarticle,theSm-dopingsinglecrystalsCa1-xSmxFe2As2(x=00.2)werepreparedbytheCaAsfluxmethod,andfollowedbyarapidquenchingtreatmentafterthehightemperaturegrowth.Thesampleswerecharacterizedbystructural,resistive,andmagneticmeasurements.ThesuccessfulSm-substitutionwasrevealedbythereductionofthelatticeparameterc,duetothesmallerionicradiusofSm3+thanCa2+.SuperconductivitywasobservedinallsampleswithonsetTcvaryingfrom27Kto44KuponSm-doping.ThecoexistenceofacollapsedphasetransitionandthesuperconductingtransitionwasfoundforthelowerSm-dopingsamples.ZeroresistivityandsubstantialsuperconductingvolumefractiononlyhappeninhigherSm-dopingcrystalswiththenominalx>0.10.Thedopingdependencesofthec-axislengthandonsetTcweresummarized.Thehigh-TcobservedinthesequenchedcrystalsmaybeattributedtosimultaneoustuningofelectroncarriersdopingandstraineffectcausedbylatticereductionofSm-substitution.
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:AdualSshapedmicrostripantennawitharealisticfeedisproposedforgenerationoftiltedbeamradiationpatternpertainingforbeamsteeringapplications.Toachievethis,fourfeedingpointsarelocatedatadistanceof5.6mmfromtheantennacentre.Thesefeedingpointswhenexcitedonebyonegeneratefourtiltedbeamsinfourdifferentspacequadrants,thusyieldingabeamsteerableantenna.Importantly,sincetheproposedantennaissymmetricalinthestructure,allthefourtiltedbeamshavethesameradiationpatterncharacteristics.Afurtherenhancementoftheantennabandwidthisalsoachievedusing100-μmcapacitivecouplingbetweenthefeedandtheantennastrip.
简介:SECRALIIisthesecondfullysuperconductingECRionsourcedevelopedatIMP.It’salmosttheduplicateofSECRAL,exceptforthecryogenicsystem[1].SECRALIIhasintegratedLHerecondensationsystem,whichhasthedynamiccoolingcapacityofmorethan5W.ThemainparametersofSECRALI&IIareshowninTable1.ThemagnetsofSECRALIIhasbeensuccessfullyfabricatedandtestedin2015.In2016,SECRALIIhasbeencommissionedat18and28GHzwithOandXeionbeams,whichhasgivenverypromisingresults.
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简介:A60%Fe/Al2O3catalystwaspreparedbytheco-precipitationmethod.ItwasreducedbyH2toproducemetallicFe,whichwasthensulfidedbyCS2toFe0.96SandFe3S4orphosphidedbytriphenylphosphine(PPh3)inliquidphasestoFe2PandFeP.Itwasfoundthattheironsulfides(Fe0.96SandFe3S4)exhibitedthelowactivityforthehydrodesulfurization(HDS)reactions.TheHDSactivitywasalsolowontheFe(metal)/Al2O3andFe2P/Al2O3catalystssincetheywereconvertedintoFe0.96SandFe3S4duringtheHDSreactions.Incontrast,theFeP/Al2O3wasfoundtobestableandactivefortheHDSreactions.Inparticular,FeP/Al2O3possessedsignificantlysmallerFePparticlesthanFeP/C,leadingtothesignificanthigherHDSactivityofFeP/Al2O3thanFeP/C.