简介:Inthecontextoftopcolor-assistedtechnicolor(TC2)model,westudythechargedandneutraltop-pionsproductionprocessγγ→W~+П_t~-П_t~0.Wefindthattheproductioncrosssectionislargerthanthatoftheprocessγγ→W~+H~-Hintheminimalsupersymmetricstandardmodel.WithreasonablevaluesoftheparametersintheTC2model,thecrosssectioncanreachthelevelofafewfb.Furthermore,theflavor-changing(FC)decaymodeП_t~0→tcisthebestchanneltodetecttheneutraltop-pionduetothecleanSMbackground.Withalargenumberofeventsandthecleanbackground,theneutraltop-pionshouldbeobservableatfuturelinearcollidersoperatinginγγmodeattheTeVenergyscale.
简介:WesuggesttwoschemestogeneratetheWstateofNA-typethree-levelatoms.Intheschemes,identicalNthree-levelatomsaretrappedinacavityorNdistantcavities.ThesuccessorfailureofthegenerationoftheWstatecanbedeterminedbydetectingthepolarizationofphotonleakingoutofthecavity.TheresultdemonstratesthattheWstateisfreefromboththecavitylossandthespontaneousemissionduetothefactthatthetwogroundstates(leftandright)ofthethree-levelatomsarestablestates(ormetastablestates).
简介:Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.
简介:WedemonstrateamonolithicsinglefrequencyTm-dopedfiberamplifierwithoutputpowerof51.5W.Asinglefrequencyfiberlaserat1.97μmisamplifiedbyacascadedmasteroscillatorpoweramplifier(MOPA)systemwithall-fiberconfiguration.Theoptical-to-opticalconversionefficiencyofthemainfiberamplifieris45%.Noamplifiedspontaneousemission(ASE)orstimulatedBrillouinscattering(SBS)effectisobservedinthefiberamplifier.Theoutputpowercouldbefurtherscaledbylaunchingmorepumppower.
简介:Variousagriculturalcropresiduesincludingcornstover,corncob,andsorghumstalkwithamoisturecontentof75wt%weresubjectedtoalongpretreatment(12-60h)withsupercriticalCO2(scCO2),atlowtemperature(50-80℃)andapressureof17.5-25.0Mpa.Thesugaryieldsfromtheenzymatichydrolysis(EH)ofthepretreatedsampleswereasmuchasthree-tofourfoldgreaterthanthoseaffordedbytherawmaterials.However,whenpretreatmentwasconductedwithinashorttime(e.g.0.5h),aspreviouslyreportedintheliterature,onlyaslightincreaseintheEHsugaryieldswasobserved.TheproposedscCO2pretreatmentmechanismdemonstratedtheroleofmoistureinthesystem.Wetting,softening,andswellingwereobservedtomainlyaffectthelignocellulosewhenasuitableamountofwaterwasadded.Finally,thesampleswereanalysedbyX-raydiffractionandscanningelectronmicroscopy,beforeandafterpretreatment,toinvestigatethechangesinthemicroscopicstructureofthebiomass.
简介:Twoschemesforteleportinganunknownone-particlestateareproposedwhenageneralWstateisutilizedasquantumchannel.Inthefirstscheme,afterthesender(Alice)makesaBell-statemeasurementonherparticles,therecipient(Bob)performsaVonNeumannmeasurementandintroducesanauxiliaryparticle,andcarriesoutaunitarytransformationonhisparticleandtheauxiliaryparticle,andperformsaVonNeumannmeasurementontheauxiliaryparticletoconfirmwhethertheteleportationsucceedsornot.Inthesecondscheme,therecipient(Bob)doesnotneedtoperformthefirstVonNeumannmeasurementorintroducetheauxiliaryparticle,whichisnecessaryinthefirstscheme.Itisshownthatthemaximalprobabilitiesofsuccessfulteleportationofthetwoschemesareidenticaliftherecipient(Bob)performsanappropriateunitarytransformationandadoptsaproperparticleonwhichherecoversthequantuminformationofstatetobeteleported.
简介:Parametersforthe3W1sourceatBSRFweredeterminedinboththededicatedandparasiticmodeandtheirsuitabilityforproteincrystallographybeamlineatBSRFwererealized.Itisdiscussedthatthephysicsmotivationandthedesignofthe3W1iscomparedwithsimilarexperimentalstationsattheBrazilianLightSourec(1.37Gev)andMax-IIinSweden(1.5GeV).Thephotonfluxfromthe3W1sourcdisabout2×10^11photon/smAinthewavelengthrangeof2.0-0.9Ainparasiticmodeand50-80timeshigherinthededicatedmode.Boththededicatedandparasiticmodesaresuitableformacromolecularstructureexperiments.2001ElsevierScienceB.V.Allrightsreserved.
简介:WehavedepositedW/Simultilayermirrorsusingthemagnetronsputteringunderthelowsputteringpressureandthehighmagneticfieldstrength,andmeasuredtheirreflectivtityinBeijingsynchrotronradiationfaciltiy,W/Simultilayershowthepeakreflectivityofapproximately10%ataphotonenergyof1200eVand10.5%ataphotoenergyof700eVrespectivelyattheincidenceangleof81°。
简介:Inthispaper,weinvestigateperfectquantumteleportationanddensecodingbyusingan2N-qubitWstatechannel.Inthequantumteleportationscheme,anunknownN-qubitentangledstatecanbeperfectlyteleported.Oneebitofentanglementandtwobitsofclassicalcommunicationareconsumedintheteleportationprocess,justlikewhenusingtheBellstatechannel.WhileN+1bitsofclassicalinformationcanbetransmittedbyonlysendingNparticlesinthedensecodingprotocol.
简介:Amethodtopreparemulti-particleentanglementofGreenberger-Horne-Zeilinger-typeandW-typeisproposedthroughtheinteractionbetweenthecavityandmanyatomssimultaneously.Aftersuitableinteraction,theselectedmeasurementsonthecavityfieldcancreatetheentangledatomicstates.Theseentangledstatescanbeusefulforquantuminformationmanipulationandfundamentalstudyofquantumtheory.ThesestatesthatviolatetheBell'sinequalityareproven.