简介：Thepyrolyzedcarbonsupportedferrumpolypyrrole(Fe-N/C)catalystsaresynthesizedwithorwithoutselecteddopants,p-toluenesulfonicacid(TsOH),byafacilethermalannealingapproachatdesiredtemperatureforoptimizingtheiractivityfortheoxygenreductionreaction(ORR)inO2-saturated0.1mol/LKOHsolution.Theelectrochemicaltechniquessuchascyclicvoltammetry(CV)androtatingdiskelectrode(RDE)areemployedwiththeKoutecky-LevichtheorytoquantitativelyobtaintheORRkineticconstantsandthereactionmechanisms.ItisfoundthatcatalystsdopedwithTsOHshowsignificantlyimprovedORRactivityrelativetotheTsOH-freeone.TheaverageelectrontransfernumbersforthecatalyzedORRaredeterminedtobe3.899and3.098,respectively,forthecatalystswithandwithoutTsOH-doping.Theheat-treatmentisfoundtobeanecessarystepforcatalystactivityimprovement,andthecatalystpyrolyzedat600℃givesthebestORRactivity.Anonsetpotentialandthepotentialatthecurrentdensityof-1.5mA/cm2forTsOH-dopedcatalystafterpyrolysisare30mVand170mV,whicharemorepositivethanthosewithoutpyrolized.Furthermore,thecatalystdopedwithTsOHshowshighertolerancetomethanolcomparedwithcommercialPt/Ccatalystin0.1mol/LKOH.TounderstandthisTsOHdopingandpyrolyzedeffect,X-raydiffraction(XRD),scanningelectronmicroscope(SEM)andX-rayphotoelectronspectroscopy(XPS)areusedtocharacterizethesecatalystsintermsoftheirstructureandcomposition.XPSresultsindicatethatthepyrrolic-Ngroupsarethemostactivesites,afindingthatissupportedbythecorrespondencebetweenchangesinpyridinic-NcontentandORRactivitythatoccurwithchangingtemperature.SulfurspeciesarealsostructurallyboundtocarbonintheformsofC–Sn–C,anadditionalbeneficialfactorfortheORR.

简介：Wedevelopadualporous(DP)TiO_2filmfortheelectrontransportinglayer(ETL)incarboncathodebasedperovskitesolarcells(C-PSCs).TheDPTiO_2filmwassynthesizedviaafacilePS-templatedmethodwiththethicknessbeingcontrolledbythespin-coatingspeed.ItwasfoundthatthereisanoptimumDPTiO_2filmthicknessforachievinganeffectiveETL,asuitableperovskite/TiO_2interface,anefficientlightharvesterandthusahighperformanceC-PSC.Inparticular,suchaDPTiO_2filmcanactasascaffoldforcomplete-fillingoftheporeswithperovskiteandforforminghigh-qualityperovskitecrystalsthatareseamlesslyinterfacedwithTi_O2toenhanceinterfacialchargeinjection.LeveragingtheuniqueadvantagesofDPTiO2ETL,togetherwithadense-packedandpinhole-freeTiO_2compactlayer,PCEoftheC-PSCshasreached9.81%withgoodstability.

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简介：Aone-dimensional(1D)fluidsimulationofdualfrequencydischargeinheliumgasatatmosphericpressureiscarriedouttoinvestigatetheroleofthesecondaryelectronemissiononthesurfacesoftheelectrodes.Inthesimulation,electrons,ionsofHe+andHe2+,metastableatomsofHe*andmetastablemoleculesofHe*2areincluded.Itisfoundthatthesecondaryelectronemissioncoefficientsignificantlyinfluencesplasmadensityandelectricfieldaswellaselectronheatingmechanismsandionizationrate.TheparticledensitiesincreasewithincreasingSEEcoefficientfrom0to0.3aswellasthesheath’selectricfieldandelectronsource.Moreover,theSEEcoefficientalsoinfluencestheelectronheatingmechanismandelectronpowerdissipationintheplasmaandbothofthemincreasewithincreasingSEEcoefficientwithintherangefrom0to0.3asaresultofincreasingofelectrondensity.

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简介：Weproposeanultra-simpledual-channelconfigurationforsimultaneouslyevaluatingtwobranchesofamultifunctionalintegratedopticchip(MFIOC).Intheconfiguration,theMFIOCisemployedasabeamsplittertoconstructthedemodulationinterferometertogetherwitha2×2fibercoupler.InterferencehappensbetweenpolarizationmodestravelingthroughdifferentchannelsoftheMFIOC.Thecross-couplingsofeachchannelarerespectivelycharacterizedbytheinterferencepeakswhichdistributeonoppositesidesofthecentralinterferencepeak.TemperatureresponsesoftheMFIOCareexperimentallymeasuredfrom-40°Cto80°C.Resultsshowthattheproposedconfigurationcanachievesimultaneousdual-channeltransientmeasurementswithresolutionof-90dBanddynamicrangeof90dB.Inaddition,thetwochannelsoftheconfigurationhaveconsistentmeasuringperformance,andthetwobranchesoftheMFIOChavedifferentresponsestotemperaturevariation.

简介：Wereportedonthegenerationofthedual-wavelengthrectangularpulseinanerbium-dopedfiberlaser(EDFL)withatopologicalinsulatorsaturableabsorber.Therectangularpulsecouldbestablyinitiatedwithpulsewidthfrom13.62to25.16nsandfundamentalrepetitionrateof3.54MHzbyproperlyadjustingthepumppowerandthepolarizationstate.Inaddition,weverifiedthatthepulseshapeofthedual-wavelengthrectangularpulsecanbeaffectedbythetotalnetcavitydispersioninthefiberlaser.Furthermore,byproperlyrotatingthepolarizationcontrollers,theharmonicmode-lockingoperationofthedual-wavelengthrectangularpulsewasalsoobtained.Thedual-wavelengthrectangularpulseEDFLwouldbenefitsomepotentialapplications,suchasspectroscopy,biomedicine,andsensingresearch.

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简介：UsingadoubleresonantKTiOPO4(KTP)intracavityopticalparametricoscillatoroperatingatdegeneratedpointof2μm,wedemonstrateauniquemid-infraredsourcebasedondifferencefrequencygenerationinGaSecrystal.Theoutputtuningrangeis8.42-19.52μm,andapeakpowerof834Wfortype-Iphasematchingschemeand730Wfortype-IIphasematchingschemeareachieved.Experimentalresultsshowthatthisoscillatorisagoodalternativetothegeneratorofacompactandtabletopmid-infraredradiationwithawidelytunablerange.

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简介：Aseriesofoxygenpermeabledual-phasecompositeoxides60wt%Ce0.8Gd0.2O2-δ-40wt%LnBaCo2O5+δ(CGO-LBCO,Ln=La,Pr,Nd,Sm,GdandY)weresynthesizedthroughasol-gelrouteandeffectsoftheLn3+cationsontheirphasestructure,oxygenpermeabilityandchemicalstabilityagainstCO2wereinvestigatedsystemicallybyXRD,SEM,TG-DSCandoxygenpermeationexperiments.XRDpatternsrevealthatthelargerLn3+cations(La3+,Pr3+andNd3+)successfullystabilizedthedouble-layeredperovskitestructureofsinteredLBCO,whilethesmallerones(Sm3+,Gd3+,andY3+)resultedinthepartialdecompositionofLBCOwithsomeimpuritiesformed.CGO-PBCOyieldsthehighestoxygenpermeationflux,reaching2.8×10-7mols-1cm-2at925?Cwith1mmthicknessunderair/Hegradient.TheTG-DSCprofilesin20mol%CO2/N2andoxygenpermeabilityexperimentswithCO2assweepgasshowthatCGO-YBCOdemonstratesthebestchemicalstabilityagainstCO2,possiblyduetoitsminimumbasicity.ThestableoxygenpermeationfluxofCGO-YBCOunderCO2atmosphererevealsitspotentialapplicationintheoxy-fuelcombustionrouteforCO2capture.

简介：LiMn2O4andLiNixAlyMn2-x-yO4（x=0.50;y=0.05-0.50）powdershavebeensynthesizedviafacilesolgelmethodusingBehenicacidasactivecheiatingagent.Thesynthesizedsamplesaresubjectedtophysicalcharacterizationssuchasthermogravimetricanalysis（TG/DTA）,X-raydiffraction（XRD）,Fouriertransforminfraredspectroscopy（FT-IR）,field-emissionscanningelectronmicroscopy（FESEM）,transmissionelectronmicroscopy（TEM）andelectrochemicalstudiesviz.,galvanostaticcyclingproperties,electrochemicalimpedancespectroscopy（EIS）anddifferentialcapacitycurves（dQ/dE）.FingerprintXRDpatternsofLiMn2O4andLiNixAlyMn2-x-yO4fortifythehighdegreeofcrystallinitywithbetterphasepurity.FESEMimagesoftheundopedpristinespinelillustrateuniformsphericalgrainssurfacemorphologywithanaverageparticlesizeof0.5μmwhileNidopedparticlesdepictthesphericalgrainsgrowth（50nm）withice-cubesurfacemorphology.TEMimagesofthespinelLiMn2O4showstheuniformsphericalmorphologywithparticlesizeof（100nm）whilelowlevelofAl-dopingspinel（LiNio.5Alo.05Mn1.45O4）displayingcloudyparticleswithagglomeratedparticlesof（50nm）.TheLiMn2O4samplescalcinedat850℃deliverthedischargecapacityof130mAh/ginthefirstcyclecorrespondsto94%coiumbicefficiencywithcapacityfadeof1.5mAh/g/cycleovertheinvestigated10cycles.Amongallfourdopantcompositionsinvestigated,LiNi0.5Al0.05Mn1.45O4deliversthemaximumdischargecapacityof126mAh/gduringthefirstcycleandshowsthestablecyclingperformancewithlowcapacityfadeof1mAh/g/cycle（capacityretentionof92%）overtheinvestigated10cycles.ElectrochemicalimpedancestudiesofspinelLiMn2O4andLiNi0.5Al0.05Mn1.45O4depictthehighandlowrealpolarizationof1562and1100Ω.

简介：Wehavedemonstratedahigh-average-power,high-repetition-rateopticalterahertz（THz）sourcebasedondifferencefrequencygeneration（DFG）intheGaSecrystalbyusinganear-degenerate2μmintracavityKTPopticalparametricoscillatorasthepumpsource.Thepowerofthe2μmdual-wavelengthlaserwasupto12.33Wwithcontinuoustuningrangesof1988.0–2196.2nm/2278.4–2065.6nmfortwowaves.DifferentGaSecystallengthshavebeenexperimentallyinvestigatedfortheDFGTHzsourceinordertooptimizetheTHzoutputpower,whichwasingoodagreementwiththetheoreticalanalysis.Basedonan8mmlongGaSecrystal,theTHzwavewascontinuouslytunedfrom0.21to3THz.ThemaximumTHzaveragepowerof1.66μWwasobtainedatrepetitionrateof10kHzunder1.48THz.Thesinglepulseenergyamountedto166pJandtheconversionefficiencyfrom2μmlasertoTHzoutputwas1.68×10-6.Thesignal-to-noiseratioofthedetectedTHzvoltagewas23dB.TheacceptanceangleofDFGintheGaSecrystalwasmeasuredtobe0.16°.