学科分类
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15 个结果
  • 简介:Near-fleldcoupledplasmonicsystemsgenerallyachieveplasmonicallyinducedtransparency(PIT)usingonlyone-waybright-darkmodecoupling.However,itischallengingtorealizesuchwell-designeddevices,mainlybecausetheydependsignificantlyonthepolarizationdirection.Weexploitsurfaceplasmonssup-portedbytwocrossedlayersofgraphenenanoribbons(GNRs)toachievedynamicallytunablePIT,whereeachGNRoperatesasboththebrightanddarkmodessimultaneously.TheproposedPITcanresultfromeitherone-waybright-darkmodeinteractionsorbidirectionalbright-brightandbright-darkmodehybrid-izedcouplingwhenthepolarizationisperpendicular/paralleloratanangletotheGNRs,respectively.Additionally,identicalribbonwidthsyieldpolarization-insensitivesingle-windowPIT,whereasdifferentribbonwidthsproducepolarization-dependentdouble-windowPIT.Weexaminetheproposedtechniqueusingplasmonwavefunctionsandthetransfermatrixmethod;analyticalandnumericalresultsshowex-cellentagreement.ThisstudycanprovidephysicalinsightintothePITcouplingmechanismsandadvancetheanulicabilitvandversatilityofPIT-basedsensingplatformsandotheractivedevices.

  • 标签: 近场耦合 等离子体系统 通讯技术 发展现状
  • 简介:线性链烷的混合物的吸附等温线,包含n戊烷,n己,;在pillared的n-heptane有三不同的孔Ω=的分层的材料(PLM)0.98,0.94;0.87,;三毛孔宽度H=1.02,1.70;在温度T=300K的2.38nm被使用configurational偏爱蒙特卡罗(CBMC)模仿在宏大正规整体的技术。一个格子模特儿被雇用计算在一个液体分子之间的相互作用;这里的二块分层的板。为链烷混合物,n-heptane,在链烷混合物的最长的链部件,优先地在低压力被吸附,与它增加的吸附;当时,然后作为压力减少连续地增加n戊烷,在链烷混合物的最短的链部件,仍然在高压力被吸附;链烷混合物的最长的链部件的吸附作为毛孔宽度增加;PLM增加的孔。

  • 标签: 石化工业 吸附行为 烷烃 低温条件
  • 简介:IntheinterlayerexpansionofthelayeredzeoliteprecursorCOK-5,aSn,salt,bis(2,4-pentanedionate)-dichlorotin[Sn(acac)2Cl2],insteadofasilylatingagentwasusedtolinkthelayersat180°C.Theobtainedmaterial,whichisdesignedasSn-COE-5,showsashiftofthefirstXRDreflection,whichisverysimilartothatofCOK-5interlayerexpandedwithdichlorodimethylsilane(DCDMS),indicatinganincreaseininterlayerdistance.X-raydiffraction(XRD),N2sorptionisotherms,inductivelycoupledplasma(ICP),andX-rayphotoelectronspectroscopy(XPS)supporttheincorporationofisolatedSnsitesinthesample.Intheconversionofglucosetolevulinicacid,Sn-COE-5exhibitsmuchhigheractivitythanCOK-5,whichisduetothepresenceofLewisacidicsitesintheSn-COE-5.

  • 标签: 前驱体 分子筛 层间 SN 层状 膨胀
  • 简介:Aserialofprotonatedandlayeredtransitionmetaloxides,includinglayeredHTaWO6,HNbMoO6aswellasHNbWO6,weresynthesizedbysolid-statereactionandion-exchange.ThelayeredHTaWO6hasbeensystematicallystudiedasasolidacidtorealizethedehydrationoffructoseto5-hydroxymethylfurfural(HMF).ThetransitionmetaloxidesampleswerecharacterizedwithICP-OES,EDS,XRD,XPS,SEM,TGA,FT-IR,N2adsorption–desorptionandNH3-TPD.Theinfluentialfactorssuchasreactiontemperature,reactiontime,solvent,catalystamountandsubstrateconcentrationweredeeplyinvestigated.Theoptimizedfructoseconversionrateof99%withHMFyieldof67%wereachievedafter30minat140°Cindimethylsulfoxide.

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  • 简介:TheBrenner-LJpotentialisadoptedtodescribetheinteractionbetweenC36clustersanddiamondsurface,andthedepositionmechanismofmulti-C36clustersonthediamondsurfaceisalsostudiedbyusingthemethodofmoleculardynamicssimulation.Thesimulationresultsshowthatthecompetitioneffectsoftwointeractions,i.e.theinteractionbetweenclusterandclusterandtheinteractionbetweenclusterandcrystalplane,arestudied,andthentheinfluenceofthesecompetitioneffectsonC36clusterdepositionisanalysed.Thefindingisthatwhenanincidentenergyisappropriatelychosen,C36clusterscanbechemicallyadsorbedanddepositedsteadilyonthediamondsurfaceintheformofsingle-layer,andinthedepositionprocessthemulti-C36clusterspresentaphenomenonofenergytransmission.Theexperimentalresultshowsthatatatemperatureof300K,inordertodepositC36clustersintoasteadynano-structuredsingle-layeredfilm,theoptimalincidentenergyisbetween10and18eV,iftheincidentenergyislargerthan18eV,theC36clusterswillbedepositedintoanislandnano-structuredfilm.

  • 标签: 单层碳膜 纳米材料 纳米结构 沉积机制
  • 简介:InsituhighpressureenergydispersiveX-raydiffractionmeasurementsonlayeredperovskite-likemanganateCa3Mn2O7underpressuresupto35GPahavebeenPerformedbyusingdiamondanvilcellwithsynchrotronradiation.Theresultsshowthatthestructureoflayeredperovskite-likemanganateCa3Mn2O7isunstableunderpressureduetotheeasycompressionofNaCl-typeblocks.ThestructureofCa3Mn2O7underwenttwophasetransitionsunderpressuresintherangeof0-35GPa.Onewasatabout1.3GPawiththecrystalstructurechangingfromtetragonaltgoorthorhombic.Theotherwasatabout9.5GPawiththecrystalstructurechangingformorthorhombicbacktoanothertetragonal.

  • 标签: 高压 X射线衍射 Ca3Mn2O7 钙钛矿结构 锰酸盐晶体 相变
  • 简介:ThisstudyshowsthepreparationofaTiO_2coatedPt/C(TiO_2/Pt/C)byatomiclayerdeposition(ALD),andtheexaminationofthepossibilityforTiO_2/Pt/Ctobeusedasadurablecathodecatalystinpolymerelectrolytefuelcells(PEFCs).CyclicvoltammetryresultsrevealedthatTiO_2/Pt/Ccatalystwhichhas2nmprotectivelayershowedsimilaractivityfortheoxygenreductionreactioncomparedtoPt/Ccatalystsandtheyalsohadgooddurability.TiO_2/Pt/Cpreparedby10ALDcyclesdegraded70%after2000Accelerateddegradationtest,whilePt/Ccorroded92%inthesameconditions.TiO_2ultrathinlayerbyALDisabletoachieveagoodbalancebetweenthedurabilityandactivity,leadingtoTiO_2/Pt/CasapromisingcathodecatalystforPEFCs.ThemechanismoftheTiO_2protectivelayerusedtopreventthedegradationofPt/Cisdiscussed.

  • 标签: 聚合物电解质燃料电池 纳米二氧化钛 阴极催化剂 原子层沉积 耐久性 铂碳
  • 简介:AnewlayeredCu-basedoxychalcogenideBa3Fe2O5Cu2S2hasbeensynthesizedanditsmagneticandelectronicpropertieswererevealed.Ba3Fe2O5Cu2S2isbuiltupbyalternativelystacking[Cu2S2]2-layersandironperovskiteoxide[(FeO2)(BaO)(FeO2)]2-layersalongthecaxisthatareseparatedbybariumionswithFe3+fivefoldcoordinatedbyasquare-pyramidalarrangementofoxygen.Fromthebondvalencearguments,weinferredthatinlayeredCuCh-based(Ch=S,Se,Te)compoundsthe+3cationinperovskiteoxidesheetprefersasquarepyramidalsite,whilethelowervalencecationprefersthesquareplanarsites.Thestudiesonsusceptibility,transport,andopticalreflectivityindicatethatBa3Fe2O5Cu2S2isanantiferromagneticsemiconductorwithaNe′eltemperatureof121Kandanopticalbandgapof1.03eV.Themeasurementofheatcapacityfrom10Ktoroomtemperatureshowsnoanomalyat121K.TheDebyetemperatureisdeterminedtobe113K.TheoreticalcalculationsindicatethattheconductionbandminimumispredominantlycontributedbyO2pand3dstatesofFeionsthatantiferromagneticallyarrangedinFeO2layers.TheFe3dstatesarelocatedatlowerenergyandresultinanarrowbandgapincomparisonwiththatoftheisostructuralSr3Sc2O5Cu2S2.

  • 标签: 钙钛矿型氧化物 铁磁半导体 光学带隙 德拜温度 电子性质 阳离子