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简介：Backscatteredfieldsfromone-dimensionaltime-varyingGerstnersseasurfacearecalculatedutilisingthesecondordersmallslopeapproximation.Itiswellknownthatspectralpropertiesofthebackscatteredechoesrelatetothevelocityofthesmallelementaryscatterersonseasurfaceprofiles.Therefore,modelingDopplerspectrafromtheoceanrequiresanaccuratedescriptionoftheseasurfacemotion.TheprofileofnonlinearGerstnersseasurfaceshowsverticalskewnessofseawaves,itissharperatthecrestandflatteratthetroughthanlinearwaves,anditsmaximumslopepositionisclosertothecrestthantothetrough.Furthermore,thehorizontalcomponentofthesmallelementaryscatterersorbitvelocityontheseasurface,whichyieldsnoticeableinfluenceonDopplerspectra,canbeobtainedconvenientlybyGerstnersseasurfacemodel.Inthisstudy,thecharacteristicsofDopplerspectraofbackscatteredfieldsfromtime-varyingGerstnersseasurfaceareinvestigatedandthedependencesoftheDopplerfrequencyandtheDopplerbandwidthontheparameters,suchasthewindspeed,theradarfrequency,theincidentangle,etc.arediscussed.ItisshownthattheDopplerbandwidthofmicrowavescatteredfieldsfromGerstnersseasurfaceisconsiderablybroadened.Forthecaseofhighfrequencybackscatteredfields,thevaluesofthehigher-orderspectrumpeaksarelargerthanthoseobtainedbylinearseasurface.

简介：PlasmonicresonancewithFanolineshapehasattractedagreatdealofrecentinterest.Herewedesignanewstructurewithadimergratinguponagoldfilmseparatedbyalayerofsilicaspacer,whichhastworesonantmodescorrespondingtothedimer’slocalizedsurfaceplasmonresonanceandthesurfaceplasmonresonanceexcitedbythedimergrating.Thisstructurehasthreeadvantagesfornear-infrareddetectioninwater.First,itprovidestworesonantmodestoenhancetheexcitationandscatteredsignalsofsurface-enhancedRamanscattering.Second,couplingofthesetwomodesresultsinaFanoresonance,providingahigherelectricfieldenhancement.Finally,thedimerprovidesmoreflexibletunabilitycomparedtoasinglediskstructure.

简介：Couplingefficiencybetweenthelocalizedsurfaceplasmons(LSPs)ofmetalnanoparticles(NPs)andincidentlightdominatesthesensitivitiesofplasmon-basedsensingspectroscopiesandimagingtechniques,e.g.,surfaceenhancedRamanscattering(SERS)spectroscopy.ManyendogenousfeaturesofmetalNPs(e.g.,size,shape,aggregationform,etc.)thathavestrongimpactsontheirLSPshavebeendiscussedindetailinpreviousstudies.Here,thepolarization-tunedelectromagnetic(EM)fieldthatfacilitatestheLSPcouplingisfullydiscussed.Numericalanalysesonwaveguide-basedevanescentfields(WEFs)coupledwiththeLSPsofdispersedsilvernanospheresandsilvernano-hemispheresarepresentedandtheapplicabilityoftheWEF-LSPstoplasmon-enhancedspectroscopyisdiscussed.ComparedwithLSPsunderdirectlightexcitationthatonlyprovide3–4timesenhancementoftheincidencefield,theWEF-LSPscanamplifytheelectricfieldintensityabout30–90times(equalingtheenhancementfactorof10~6–10~8inSERSintensity),whichiscomparabletotheEMamplificationoftheSERS'hotspot'effect.Importantly,thestrongestregionofEMenhancementaroundsilvernanospherescanbemodulatedfromthegapregiontothesidesurfacesimplybyswitchingtheincidentpolarizationfromTMtoTE,whichwidelyextendsitssensingapplicationsinsurfaceanalysisofmonolayerofmoleculeandmacromoleculedetections.Thistechniqueprovidesusauniquewaytoachieveremarkablesignalgainsinmanyplasmon-enhancedspectroscopicsystemsinwhichLSPsareinvolved.

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简介：Inthepresentwork,core-shellNi@SiO2catalystswereinvestigatedinordertoevaluatetherelevanceofcatalyticactivityandsurfacestatesofNicoreaswellasNinanoparticlessizetocatalyticpartialoxidationofmethane(POM).ThecatalystswerecharacterizedbyN2adsorption,H2-TPR,XRD,TEMandXPStechniques.Thecatalyticperformanceofthecore-shellcatalystswasfoundtobedependentonthesurfacestatesofcatalyst,whichinfluencedtheformationofproducts.Itwasconsideredthatcarbondioxideformedontheoxidizednickelsites(NiO)andcarbonmonoxideproducedonthereducedsites(Ni).ThesurfacestatesofactivemetalinthedynamicwereinfluencedbothbythesizeofNicoreandtheporosityofsilicashell.However,thecatalyticactivitywouldbedebasedwhenthesizeofNicorewasunderacertainextent,whichcanbeascribedtothefactthecarbondepositionincreasedwiththeincreasingcontentofNiO.TheeffectsofsurfacestatesofNi@SiO2catalystonthecatalyticperformancewerediscussedandthereactionpathwayoverNicoreencapsulatedinsidesilicashellwasproposed.

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简介：Inthispaper,high-speedsurface-illuminatedGe-on-Sipinphotodiodeswithimprovedeffidencyaredemon-strated.Withphoton-trappingmicroholefeatures,theexternalquantumefficiency（EQE）oftheGe-on-Sipindiodeis〉80%at1300nmand73%at1550nmwithanintrinsicGelayerofonly2μmthickness,showingmuchimprovementcomparedtoonewithoutmicroholes.MorethanthreefoldEQEimprovementisalsoob-servedatlongerwavelengthsbeyond1550nm.Theseresultsmakethemicrohole-enabledGe-on-SiphotodiodespromisingtocoverboththeexistingCandLbands,aswellasanewdatatransmissionwindow（1620-1700nm）,whichcanbeusedtoenhancethecapacityofconventionalstandardsingle-modefibercables.Thesephotodiodeshavepotentialformanyapplications,suchasinter-/intra-datacenters,passiveopticalnetworks,metroandlong-hauldensewavelengthdivisionmultiplexingsystems,eye-safelidarsystems,andquantumcommunications.TheCMOSandBiCMOSmonolithicintegrationcompatibilityofthisworkisalsoattractiveforGeCMOS,near-infraredsensing,andcommunicationintegration.

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简介：Thispaperproposesahybridmethodbasedontheforward-backwardmethod(FBM)andthereciprocitytheorem(RT)forevaluatingthescatteringfieldfromdielectricroughsurfacewitha2Dtargetaboveit.Here,theequivalentelectric/magneticcurrentdensitiesontheroughsurfaceaswellasthescatteringfieldfromitarenumericallycalculatedbyFBM,andthescatteredfieldfromtheisolatedtargetisobtainedutilizingthemethodofmoments(MOM).Meanwhile,therescatteredcouplinginteractionsbetweenthetargetandthesurfaceareevaluatedemployingthecombinationofFBMandRT.OurhybridmethodisfirstvalidatedbyavailableMOMresults.Then,thefunctionaldependencesofbistaticandmonostaticscatteringfromthetargetaboveroughsurfaceuponthetargetaltitude,incidentandscatteringanglesarenumericallysimulatedanddiscussed.Thisstudypresentsanumericaldescriptionforthescatteringmechanismassociatedwithrescatteredcouplinginteractionsbetweenatargetandanunderlyingrandomlyroughsurface.

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简介：Inthisstudy,nano-polyanlineandmanganeseoxidenanometertubularcomposites(nano-PANI@MnO2)werepreparedbyasurfaceinitiatedpolymerizationmethodandusedaselectrochemicalcapacitorelectrodematerials;andtheeffectofanilineamountonthemicrostructureandelectrochemicalperformancewasinvestigated.Themicrostructuresandsurfacemorphologiesofnano-PANI@MnO2werecharacterizedbyX-raydiffraction,scanningelectronmicroscopyandfouriertransformationinfraredspectroscope.Theelectrochemicalperformanceofthesecompositematerialswasperformedwithcyclicvoltammetry,charge–dischargetestandelectrochemicalimpedancespectroscopy,respectively.TheresultsdemonstratethatthefeedratioofanilinetoMnO2playedaveryimportantroleinconstructingthehierarchicallynano-structure,whichwould,hence,determinetheelectrochemicalperformanceofthematerials.UsingthetemplateassistedstrategyandcontrollingthefeedratioofanilinetoMnO2,thenanometertubularstructureofnanoPANI@MnO2wasobtained.Amaximumspecificcapacitanceof386F/gwasachievedinaqueous1mol/LNaNO3electrolytewiththepotentialrangefrom0to0.6V(vs.SCE).

简介：QuantumdynamicscalculationsforthetitlereactionH(2S)+S2(X3-Σg)→SH(X2Π)+S(3P)areperformedbyusingagloballyaccuratedoublemany-bodyexpansionpotentialenergysurface[J.Phys.Chem.A1155274(2011)].TheChebyshevrealwavepacketpropagationmethodisemployedtoobtainthedynamicalinformation,suchasreactionprobability,initialstate-specifiedintegralcrosssection,andthermalrateconstant.Itisfoundnotonlythatthereisareactionthresholdnear0.7eVinbothreactionprobabilitiesandintegralcrosssectioncurves,butalsothatboththeprobabilityandcrosssectionincreasefirstlyandthendecreaseasthecollisionenergyincreases.Theexistenceoftheresonancestructureinboththeprobabilityandcrosssectioncurvesisascribedtothedeeppotentialwell.Thecalculationoftherateconstantrevealsthatthereactionoccurringonthepotentialenergysurfaceoftheground-stateHS2isslowtotakeplace.