简介：Inthispaper,anovelcopper-basedcatalystforFCCgasolineimprovingtheabilityofremovalthesulfurandavoidingthelossoftheoctanenumberfromolefinsaturationbyreactiveadsorptiondesulfurization(RADS)wasinvestigated.TheseriesofCu/ZnO-Al2O3catalystswerecharacterizedbyX-raypowderdiffraction(XRD),N2adsorptionanalysisandtemperature-programmedreduction(TPR)studies,X-rayphotoelectronspectroscopy(XPS),scanningelectronmicroscope(SEM)andtransmissionelectronmicroscopy(TEM).Theexperimentresultsshowedthatthecatalystshadanoptimumdesulfurizationabilitywithcopperloading6wt%,whichthesulfurcontentsofproductdecreasedlessthan10μg/gandolefincontentsdecreasedfrom16.19%to14.14%forthelongperiodoperation.TheappropriateCuloadingcontentcouldleadtothehighactiveandlowapparentactivationenergy(Ea).Therefore,theCu-basedcatalystmaybecomeanovelcatalystforsecond-generationforreactiveadsorptiondesulfurization,whichachievesthehighdesulfurizationactiveandlowolefinssaturationtosatisfytheupgradingtheproduct.

简介：Inthispaper,wereportanexperimentaldemonstrationofenablingtechnologyexploitingresonantpropertiesofplasmonicnanoparticles,fortherealizationofwavelength-sensitiveultra-minituarized(4μm×4μm)opticalmetadevices.Tothisend,theexampleofa1.3/1.6μmwavelengthdemultiplexerisconsidered.Itstechnologicalimplementationisbasedontheintegrationofgoldcut-wire-basedmetalinesonthetopofasilicon-on-insulatorwaveguide.TheplasmonicmetalinesmodifylocallytheeffectiveindexoftheSiwaveguideandthusallowfortheimplementationofwavelength-dependentopticalpathways.The1.3/1.6μmwavelengthseparationwithextinctionratiobetweentwodemultiplexers’channelsreachingupto20dBisexperimentallydemonstrated.Theconsideredapproach,whichcanbereadilyadaptedtodifferenttypesofmaterialplanarlightwavecircuitplatformsandnanoresonators,issuitedfortheimplementationofagenericfamilyofwavelength-sensitiveguided-waveopticalmetadevices.

简介：Polarizationmanipulationisasignificantissueforartificialmodulationoftheelectromagnetic(EM)wave,butgeneralmechanismsallsuffertherestrictionofinherentsymmetricpropertiesbetweenoppositehandedness.Herein,astrategytoindependentlyandarbitrarilymanipulatetheEMwavewithorthogonalcircularpolarizationsbasedonametasurfaceisproposed,whicheffectuallybreaksthroughtraditionalsymmetricalcharacteristicsbetweenorthogonalhandedness.Bysynthesizingthepropagationphaseandgeometricphase,theappropriateJonesmatrixiscalculatedtoobtainindependentwavefrontmanipulationofEMwaveswithoppositecircularpolarizations.Twotransmissiveultra-thinmeta-deflectorsareproposedtodemonstratetheasymmetricalrefractionoftransmittedcircularlypolarizedwavesinthemicrowaveregion.Simulatedtransmittedphasefrontandmeasuredfar-fieldintensitydistributionsareinexcellentagreement,indicatingthatthetransmittedwavewithdifferentpolarizationscanberefractedintoarbitraryandindependentdirectionswithinawidefrequencyband(relativebandwidthof25%).TheresultspresentedinthispaperprovidemorefreedomforthemanipulationofEMwaves,andmotivatetherealizationsofvariouspolarization-independentpropertiesforallfrequencyspectra.