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.
简介:Synergisticeffectsoflayereddoublehydroxide(LDH)withintumescentflameretardanct(IFR)ofphosphorus-nitrogen(NP)compoundinthepolypropylene/ethylene-propylene-diene/IFR/LDH(PP/EPDM/IFR/LDH)nanocompositesandrelatedpropertieswerestudiedbyX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),scanningelectronmicroscopy(SEM),limitingoxygenindex(LOI),UL-94test,conecalorimetertest(CCT)andthermo-gravimetricanalysis(TGA).TheXRDandTEMresultsshowthattheintercalatedand/orexfoliatednanocompositescanbeobtainedbydirectmelt-intercalationofPP/EPDMintomodifiedLDHandthatLDHcanpromotetheIFRadditiveNPtodispersemorehomogeneouslyinthepolymermatrix.TheSEMresultsprovidepositiveevidencethatmorecompactcharredlayerscanbeobtainedfromthePP/EPDM/NP/LDHsamplethanthosefromthePP/EPDM/LDHandPP/EPDM/NPsamplesduringburning.TheLOIandUL-94ratingtestsshowthatthesynergeticeffectsofLDHwithNPcaneffectivelyincreasetheflameretardantpropertiesofthePP/EPDM/NP/LDHsamples.ThedatafromtheCCTandTGAtestsindicatethatthePP/EPDM/NP/LDHsamplesapparentlydecreasetheHRRandMLRvaluesandthusenhancetheflameretardantpropertiesandhavebetterthermalstabilitythanthePP/EPDM/LDHandPP/EPDM/NPsamples.
简介:Layereddoublehydroxides(LDHs)withhydrotalcite-typestructurecontainingFe3+,Al3+andMg2+werepreparedbymeansofacoprecipitationmethod.Theproductswerecharacterizedbyelementanalysis,X-raypowderdiffractionandtransmissionelectronmicroscopy.Itwasfoundthatevenifthemolarratioofn(Fe+Al)/n(Fe+Al+Mg)>0.33,yetapurehydrotalcite-likecompound(HTlc)phasewasgainedwhenn(Fe)/n(Al+Mg+Fe)≤0.30andn(Al)/n(Al+Mg+Fe)≤0.30;theAl(OH)3phaseappearedintheproductswhenn(Al)/n(Al+Mg+Fe)>0.30;andanamorphousphaseemergedwhenn(Fe)/n(Al+Mg+Fe)>0.33.TheseresultsshowthatthereisnoconcentrationsuperpositioneffectbetweenFe3+andAl3+onthecrystallinestateoftheproducedsamples.Inourpreviouswork,theconcentrationsuperpositioneffectbetweenZn2+andMg2+inthesynthesisofZn-Mg-Al-LDHswasfound.ForthepreparedFe-Al-Mg-LDHssamples,thevalueoflatticeparameteraisbetween0.30-0.32nm;andthevalueoflatticeparametercisbetween2.30-2.47nm,thebasalspacingisintherangeof0.76-0.83nm.Whentheratioofn(Fe)/n(Al)isaconstant,thevaluesofaandcincreasewiththeincreaseoftheMg2+contentoftheproducedsamples.Themeanparticlesizeandthemeancrystalgrainweredeterminedbyvirtueofaparticle-sizeinstrument,XRD-ScherrerformulaandTEMmethod,respectively.
简介:Aperiodiclayeredmedium,withunitcellsconsistingofadielectricandanelectromagnetically-inducedtransparency(EIT)-basedatomicvapor,isdesignedforlightpropagationmanipulation.Consideringthatadestructivequantuminterferencerelevanttoatwo-photonresonanceemergesinEIT-basedatomsinteractingwithbothcontrolandprobefields,anEIT-basedperiodiclayeredmediumexhibitsaflexiblefrequency-sensitiveopticalresponse,whereaverysmallvariationintheprobefrequencycanleadtoadrasticvariationinreflectanceandtransmittance.ThepresentEIT-basedperiodiclayeredstructurecanresultincontrollableopticalprocessesthatdependsensitivelyontheexternalcontrolfield.Thetunableandsensitiveopticalresponseinducedbythequantuminterferenceofamulti-levelatomicsystemcanbeappliedinthefabricationofnewphotonicandquantumopticaldevices.Thismaterialwillalsoopenagoodperspectivefortheapplicationofsuchdesignsinseveralnewfields,includingphotonicmicrocircuitsorintegratedopticalcircuits.
简介:InsituhighpressureenergydispersiveX-raydiffractionmeasurementsonlayeredperovskite-likemanganateCa3Mn2O7underpressuresupto35GPahavebeenPerformedbyusingdiamondanvilcellwithsynchrotronradiation.Theresultsshowthatthestructureoflayeredperovskite-likemanganateCa3Mn2O7isunstableunderpressureduetotheeasycompressionofNaCl-typeblocks.ThestructureofCa3Mn2O7underwenttwophasetransitionsunderpressuresintherangeof0-35GPa.Onewasatabout1.3GPawiththecrystalstructurechangingfromtetragonaltgoorthorhombic.Theotherwasatabout9.5GPawiththecrystalstructurechangingformorthorhombicbacktoanothertetragonal.
简介:Usingthetimereversal(TR)-reversetimemigration(RTM)mixedmethod,thenumericalanalysistowardstheacousticfieldfordetectionandlocationoftargetsinlayeredmediaisperformed.Firsttheapproachesandstepsofthenumericalanalysisandsimulationforacousticfieldareproposed,then,theacousticfielddistributionofsingletargetandmultipletargetsarefurthercomputedbyusingtheapproachesofsingleemission-multiplereceivingandmultipleemission-multiplereceiving.Thenumericalsimulationresultsindicatethattargetdetectionandlocationcanbewellrealized.Bycomparison,goodresultsareobtainedfromthebothtwoapproaches,butlargetime-consumingisobservedinwayofmultipleemission-multiplereceiving,andsowouldbeunacceptable.Additionally,theimprovedwayisalsoproposedformultipletargetdetection.
简介:ThisstudyproposesaGreen’sfunction,anessentialrepresentationofwater-saturatedgroundundermovingexcitation,tosimulategroundbornevibrationfromtrains.First,generalsolutionstothegoverningequationsofporoelasticmediumarederivedbymeansofintegraltransform.Secondly,thetransmissionandreflectionmatrixapproachisusedtoformulatetherelationshipbetweendisplacementandstressofthestratifiedground,whichresultsinthematrixoftheGreen’sfunction.ThentheGreen’sfunctioniscombinedintoatrain-track-groundmodel,andisverifiedbytypicalexamplesandafieldtest.Additionalsimulationsshowthatthecomputedgroundvibrationattenuatesfasterintheimmediatevicinityofthetrackthaninthesurroundingarea.Thewavelengthofwheel-railunevennesshasanotableeffectoncomputeddisplacementandporepressure.Thevariationofvibrationintensitywiththedepthofgroundissignificantlyinfluencedbythelayeringofthestratasoil.WhenthetrainspeedisequaltothevelocityoftheRayleighwave,theMachconeappearsinthesimulatedwavefield.TheproposedGreen’sfunctionisanappropriaterepresentationforalayeredgroundwithshallowgroundwatertable,andwillbehelpfultounderstandthedynamicresponsesofthegroundtocomplicatedmovingexcitation.
简介:Inthepresentwork,anovelhybridcompositecomposedofTi-aluminidemulti-layeredpartandcontin-uous-SiCf-reinforcedTi-matrixpartusingavacuumhotpressing/hotisostaticpressure(VHP/HIP)sinteringprocesswassynthesized.Then,thedamagetolerancebehaviorofthishybridcompositewasstudiedbytensiletestsandinsituscanningelectronmicroscopy(SEM)three-pointbendingtests.Theresultsindicatethatthemechanicalpropertiesandcrackpropagationofthehybridcompositearestronglyinfluencedbytheextrinsictoughnessmecha-nism.Indetail,thecrackdeflectionofmulti-layeredcompositeandstrengtheningeffectofSiCf-reinforcedmatrixcompositeareobservedinthehybridcomposite.Owingtothestrengtheningeffectofcontinuous-SiCrre-inforcedTi-matrixpart,thetensilestrengthofhybridcompositeismuchhigherthanthatofneatTi-aluminidemulti-layeredcomposite.Furthermore,itisfoundthattheoptimaldamagetoleranceabilityisoptimizedwhenthenotchpositionislocatedattheTi-aluminidemulti-layeredpartduetothecrackdeflectionofmulti-layeredstructure.
简介:基于AB_5的氢存储薄电影(LaNi_(4.25)Al_(0.75)),由dc磁控管劈啪作响的扔的onCu底层在这研究被调查。X光检查衍射(XRD)表明层的微观结构在晶形。SEM和AFM分析证明这部电影看起来与近似在nmdiameter的15-40的众多的随机大小的毛孔相当不平。这部电影的结构的稳定性被DSC,XRD,andS他们,它显示这部电影在500K左右下面维持了它的结构的稳定性,和网络结构的联合分析检验在为30min在700K被加热以后在这部电影上被观察。这些电影的Electrochemicalhydrogen存储性质被模仿的电池测试调查。单人赛分层的LaNi_(4.25)Al_(0.75)大批拍摄类似于典型AB_5合金的展出电气化学的氢存储性质,这被发现,并且这部电影的最大的分泌物能力关于220mAh/g。在20个控告/解除周期以后,小塑造针的铝氧化物在电影表面的一些部分上被形成。
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.
简介:象lumped参数模型那样的分离模型和有限元素模型广泛地在地震的土壤扩大的解决方案被使用。然而,任何一个模型都精确地不估计土壤沉积物的自然频率,也不模仿一抑制频率独立。这研究基于模式等价方法为分层的土壤沉积物的一个维的粘弹性的反应分析开发一个新分离模型。新分离模型是一系列集中的群众,弹簧和缓冲筒与一种特殊配置描绘的一个一个维的相等的multi-degree-of-freedom(MDOF)系统。相等的MDOF系统的动态反应是导出的经分解,物理参数以形式的性质被提出。相等的MDOF系统与可得到的理论解决方案通过扩大函数的比较被验证。在相等的MDOF系统的自由(DOF)的度的适当数字被估计。有存在的相等的MDOF系统的比较研究分离模型被执行。建议相等的MDOF系统罐头确切介绍土壤存款抑制的自然频率和hysteretic并且向更精确的结果提供更少DOF,这被显示出。
简介:Thispaperstudiesthree-dimensionaldiffractionofobliquelyincidentplaneSHwavesbytwininfinitelylongcylindricalcavitiesinlayeredporoelastichalf-spaceusingindirectboundaryelementmethod.Theapproachisvalidatedbycomparisonwiththeliterature,andtheeffectsofcavityinterval,incidentfrequency,andboundarydrainageconditiononthediffractionarestudiedthroughnumericalexamples.Itisshownthat,theinteractionbetweentwocavitiesissignificantandsurfacedisplacementpeaksbecomelargewhentwocavitiesareclose,andthesurfacedisplacementmaybesignificantlyamplifiedbytwincavities,andtheinfluencerangewithlargeamplificationcanbeaswideas40timesofthecavityradius.Surfacedisplacementsindryporoelasticcaseandsaturatedporoelasticcaseswithdrainedandundrainedboundariesareevidentlydifferentundercertaincircumstances,andthedifferencesmaybemuchlargerthanthoseinthefree-fieldresponse.
简介:钴(公司)在自然地发生在重要数量存在锰(Mn)氧化物并且改变Mn氧化物晶体的生长。四分层的Mn氧化物,Na-buserite(Na公共汽车)并且三共同做从Mn的氧化准备的Na-buserite样品(哦)2与5%,10%,和20%Co/(Mn+公司)臼齿的比率(5Co-Na-bus,10Co-Na-bus,和20Co-Na-bus),被用来准备todorokite,地球的表面上的普通Mn氧化物,把Mg2+/Co2+离子用作一个模板。结果证明todorokites能被交换Mg2+的非做的Na-buserite的倒流处理获得,三共同做在气压的Na-buserites。然而,todorokites的形成被交换Co2+的Na公共汽车,5Co-Na-bus,和10Co-Na-bus样品的倒流处理禁止。相反,todorokite被交换Co2+的20Co-Na-bus样品的倒流处理在气压下面获得。X光检查光电子光谱学分析证明做的公司在做的Na-buserites的MnO6层作为Co3+存在。在MnO6层的代替的Co3+的数量可以作为一个模板用Co2+离子在buserite的变换起一个关键作用到todorokite。
简介:Thediblockcopolymersintercalatedlayeredsilicatewaspreparedviaameltdispersiontechnique.Thentheeffectofintercalatedhybridasfilleronacrylonitrile-butadiene-styreneresinwascharacterizedbyX-raydiffraction,transmissionelectronmicroscopy,stress-strainmeasurementsinelongation.
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.
简介:Ameshlessradialbasisfunction(RBF)collocationmethodbasedontheEringennonlocalelasticitytheoryisdevelopedtocalculatethebandstructuresofternaryandquaternarynanoscalemulti-layeredphononiccrystals(PNCs)withfunctionallygraded(FG)interlayers.Detailedcalculationsareperformedforanti-planetransversewavespropagatinginsuchPNCs.TheinfluencesofFGandhomogeneousinterlayers,componentnumber,nonlocalinterfaceimperfectionsandnanoscalesizeoncut-offfrequencyandbandstructuresareinvestigatedindetail.Numericalresultsshowthatthesefactorshavesignificanteffectsonbandstructuresatthemacroscopicandmicroscopicscales.
简介:
简介:Thecombinationofboth4,4′-bipyridine(4,4′-bipy)anddihydrogenphosphateanionligandswithcopper(Ⅱ)resultsintheformationofanovellayeredcompoundCu(4,4′-bipy)2(H2PO4)2(H2O)2.ThecrystalstructurecomprisesdiscreteneutralCu(4,4′-bipy)2(H2PO4)2(H2O)2units.Thecopperatom,locatedonthecrystallographictwofoldaxis,iscoordinatedwithtwonitrogenatomsofterminal4,4′-bipyligandsandtwowatermoleculesattheequatorialpositions,andtwodihydrogenphosphateoxygenatomsattheaxialpositions,forminganelongatedoctahedron.Thecomplexisatwo-dimensionaldistortedrhomboidalnetworkpossessingtwokindsofrhomboidswithdimensionsofca.1.6792nm×0.3203nmand1.2778nm×0.3198nm,respectively.Thetwo-dimensionalnetworksarestackedparallellyoneachotheralongc-axistogiveanextendedthree-dimensionalchannelnetworkwithaninterlayerdistanceofca.0.5030nm.Crystaldata:triclinic,spacegroupP-1,a=1.0253(2)nm,b=1.4501(3)nm,c=0.79715(16)nm,α=97.91(3)°,β=90.99(3)°,γ=85.54(3)°,V=1.1703(4)nm3,Z=2,R=0.0892,wR=0.2451.