简介:Inthisstudy,weinvestigatetheinfluenceofdopingonthechargetransferanddevicecharacteristicsparametersinthebulkheterojunctionsolarcellsbasedonpoly(3-hexylthiophene)(P3HT)andamethanofuUerenederivative(PCBM).Organicsemiconductorsarealsoknowntobenotpureandtheyhavedefectsandimpurities,someofthemarebeingchargedandactasp-typeorn-typedopants.Calculationsofthesolarcellcharacteristicsparametersversusthep-dopinglevelhavebeendoneatthreedifferentn-dopings(N_d)thatconsistof5×10~(17)cm~(-3),10~(18)cm~(-3),and5×10~(18)cm~(-3).Weperformtheanalysisofthedopingconcentrationthroughthedrift-diffusionmodel,andcalculatethecurrentandvoltagedopingdependency.Wefindthatatthreedifferentn-dopantlevels,optimump-typedopingisaboutN_p=6×10~(18)cm~(-3).Simulationresultshaveshownthatbyincreasingdopinglevel,V_(oc)monotonicallyincreasesbydoping.CellefficiencyreachesitsmaximumatsomewhathigherdopingasFFhasitspeakatN_p=3×10~(18)cm~(-3).Moreover,thispaperdemonstratesthattheoptimumvalueforthep-dopingisaboutN_p=6×10~(18)cm~(-3)andoptimumvalueforn-dopantisN_d=10~(18)cm~(-3),respectively.Thesimulatedresultsconfirmthatdopingconsiderablyaffectstheperformanceoforganicsolarcells.
简介:A60%Fe/Al2O3catalystwaspreparedbytheco-precipitationmethod.ItwasreducedbyH2toproducemetallicFe,whichwasthensulfidedbyCS2toFe0.96SandFe3S4orphosphidedbytriphenylphosphine(PPh3)inliquidphasestoFe2PandFeP.Itwasfoundthattheironsulfides(Fe0.96SandFe3S4)exhibitedthelowactivityforthehydrodesulfurization(HDS)reactions.TheHDSactivitywasalsolowontheFe(metal)/Al2O3andFe2P/Al2O3catalystssincetheywereconvertedintoFe0.96SandFe3S4duringtheHDSreactions.Incontrast,theFeP/Al2O3wasfoundtobestableandactivefortheHDSreactions.Inparticular,FeP/Al2O3possessedsignificantlysmallerFePparticlesthanFeP/C,leadingtothesignificanthigherHDSactivityofFeP/Al2O3thanFeP/C.
简介:TheeffectsofSO2,SO3ondenovosynthesisofpolychlorinateddibenzo-p-dioxins(PCDDs)anddibenzofurans(PCDFs)werestudiedusingmodelflyashesincorporatingcopperoxideandactivatedcarbon.ItwasfoundthattheinhibitiveeffectofSO2onPCDD/FsformationissimilartothatofSO3.Toinvestigatetheinhibitionmechanism,CuSO4formationsfrombothCuOandCuCl2wereexamined.TheabilityofSO3toconvertCuCl2andCuOonasilicasupportintosulfateismuchstrongerthanthatofSO2.However,replacingsilicabyactivatedcarbonleadstoamuchhighconversionofCuCl2toCuSO4inthepresenceofSO2.ThepromotionbyactivatedcarbonisexplainedbythereductionofCuCl2toCu2Cl2andtheeventualconversionofCu2Cl2intoCuSO4isthemaininhibitionmechanismofSO2ondenovosynthesisofPCDD/Fs.
简介:Multimediastreamingservedthroughpeer-to-peer(P2P)networksisboomingnowadays.However,theend-to-endstreamingqualityisgenerallyunstableduetothevariabilityofthestateofserve-peers.Ontheotherhand,proxycachingisabandwidth-efficientschemeforstreamingovertheInternet,whereasitisasubstantiallyexpensivemethodneedingdedicatedpowerfulproxyservers.Inthispaper,wepresentaP2PcooperativestreamingarchitecturecombinedwiththeadvantagesofbothP2Pnetworksandmultimediaproxycachingtechniquestoimprovethestreamingqualityofparticipatingclients.Inthisframe-work,aclientwillsimultaneouslyretrievecontentsfromtheserverandotherpeersthathaveviewedandcachedthesametitlebefore.Inthemeantime,theclientwillalsoselectivelycachetheaggregatedvideocontentsoastoservestillfutureclients.Theassociateprotocoltofacilitatethemulti-pathstreamingandadistributedutility-basedpartialcachingschemearedetailedlydis-cussed.Wedemonstratetheeffectivenessofthisproposedarchitecturethroughextensivesimulationexperimentsonlarge,Inter-net-liketopologies.
简介:AnovelSr2CuInO3Soxysulfidep-typesemiconductorphotocatalysthasbeenpreparedbysolidstatereactionmethodanditexhibitsintriguingvisiblelightabsorptionpropertieswithabandgapof2.3eV.Thep-typesemiconductorcharacterofthesynthesizedSr2CuInO3SwasconfirmedbyHallefficientmeasurementandMott-Schottkyplotanalysis.First-principlesdensityfunctionaltheorycalculations(DFT)andelectrochemicalmeasurementswereperformedtoelucidatetheelectronicstructureandtheenergybandlocations.Itwasfoundthattheas-synthesizedSr2CuInO3Sphotocatalysthasappreciateconductionandvalencebandpositionsforhydrogenandoxygenevolution,respectively.Photocatalytichydrogenproductionexperimentsunderavisiblelightirradiation(λ>420nm)werecarriedoutbyloadingdifferentmetalandmetal-likecocatalystsonSr2CuInO3SandRhwasfoundtobethebestoneamongthetestedones.
简介:P-typenitrogen-dopedZnOfilmsarepreparedsuccessfullybyin-situthermaloxidationofZn_3N_2films.Thepreparedfilmsarecharacterizedbyx-raydiffraction,non-Rutherfordbackscattering(non-RBS)spectroscopy,xrayphotoelectronspectroscopy,andphotoluminescencespectrum.TheresultsshowthattheZn_3N_2filmsstarttotransformtoZnOat400°Candthetotalnitrogencontentdecreaseswiththeincreasingannealingtemperature.Thep-typefilmsareachievedat500℃withalowresistivityof6.33Ω·cmandahighholeconcentrationof+8.82×10~(17)cm~(-3),aswellasalowlevelofcarboncontamination,indicatingthatthesubstitutionalnitrogen(N_O)isaneffectiveacceptorintheZnO:Nfilm.ThephotoluminescencespectrashowclearUVemissionsandalsoindicatethepresenceofoxygenvacancy(V_O)defectsintheZnO:Nfilms.Thep-typedopingmechanismisbrieflydiscussed.
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.
简介:P2Psystemsarecategorizedintotree-basedandmesh-basedsystemsaccordingtotheirtopologies.Mesh-basedsystemsareconsideredmoresuitableforlarge-scaleInternetapplications,butrequireoptimizationonlatencyissue.Thispaperproposesacontentsubscribingmechanism(CSM)toeliminateunnecessarytimedelaysduringdatarelaying.Anodecansendcontentdatatoitsneighborsassoonasitreceivesthedatasegment.Noadditionaltimeistakenduringtheinteractivestagespriortodatasegmenttransmissionofstreamingcontent.CSMconsistsofthreesteps.First,everynoderecordsitshistoricalsegmentslatency,andadoptsgammadistribution,whichpossessespowerfulexpressionability,toexpresslatencystatistics.Second,anodepredictssubscribingsuccessratioofeveryneighborbycomparingthegammadistributionparametersofthenodeanditsneighborsbeforeselectinganeighbornodetosubscribeadatasegment.Theabovestepswouldnotincreaselatencyastheyareexecutedbeforethedatasegmentsarereadyattheneighbornodes.Finally,thenode,whichwassubscribedto,sendsthesubscribeddatasegmenttothesubscriberimmediatelywhenithasthedatasegment.ExperimentsshowthatCSMsignificantlyreducesthecontentdatatransmissionlatency.
简介:ThespectrumoftheΣ(1193)excitedstates,Σ,withisospinI=1andstrangenessS=??1isoneofthemostimportantissuesinhadronicphysics.TheΣresonancesaremostlyproducedandstudiedinK-inducedreactions.ManyΣresonancesarenowcatalogedbytheParticleDataGroup[1].However,ourknowledgeoftheseresonancesisstillverypoor.Intheenergyregionbelow2GeV,onlyafewofthemarewellestablished,suchastheΣ(1385)ofspin-parityJP=3=2+,Σ(1670)ofJp=3=2??andΣ(1775)ofJp=5=2??.Theothersarenotwellestablishedandsomeofthemareevenoflargeuncertaintiesontheirexistence.Thus,thestudyoftheΣresonancewiththeavailableexperimentaldataisnecessary.