简介:Whenthecostofrenewableenergyharvestfromsolarandwindiscompetitivewiththepricesofelectricityfromirreversibleresourceslikecoals,theelectricitywouldbeoneofthemostpowerfulandsustainabledrivingforceforthefuturechemicalreactions.Therefore,muchefforthasbeendevotedintothedevelopmentofadvancedenergychemistryonthebasisofthemotivatedelectrocatalysis.
简介:Anumberoflaserfacilitiescomingonlineallovertheworldpromisethecapabilityofhigh-powerlaserexperimentswithshotrepetitionratesbetween1and10Hz.Targetavailabilityandtechnicalissuesrelatedtotheinteractionenvironmentcouldbecomeabottleneckfortheexploitationofsuchfacilities.Inthispaper,wereportontargetneedsforthreedifferentclassesofexperiments:dynamiccompressionphysics,electrontransportandisochoricheating,andlaser-drivenparticleandradiationsources.Wealsoreviewsomeofthemostchallengingissuesintargetfabricationandhighrepetitionrateoperation.Finally,wediscusscurrenttargetsupplystrategiesandfutureperspectivestoestablishasustainabletargetprovisioninfrastructureforadvancedlaserfacilities.
简介:Thispapernumericallystudiestheinfluenceofthedownwardspoilerdeflectionontheboundarylayerflowofahigh-lifttwo-elementairfoilconsistingofadroopnose,amainwing,adownwarddeflectingspoilerandasingleslottedflap.Bothoftheboundarylayeroftheuppersurfaceofthespoilerandtheconfluentboundarylayeroftheuppersurfaceoftheflapbecomethicker,asthedownwardspoilerdeflectionincreases.Comparedtotheattachedflowattheangleofattackof10°,theflowoftheuppersurfaceofthespoilerbecomesseparatedattheangleofattackof16°whenthespoilerdeflectionislargeenough,whichcorrespondstotheboundarylayerflowreversalinvelocityprofiles.
简介:Inrecentyears,developmentofhigh-performancesupercapacitorelectrodematerialshasstimulatedagreatdealofscientificresearch.Theelectrochemicalperformanceofasupercapacitorstronglydependsonitsmaterialstructures.Herein,wereportasimplestrategyforhigh-performancesupercapacitorsbybuildingpseudocapacitiveCuSnanosphereswithnanoporousstructures,nanosizedwalls(<10nm)andrelativelylargespecificsurfaceareaof65m~2/g.Thiselectrodedemonstratesexcellentelectrochemicalperformanceincludingamaximumspecificcapacitanceof814F/gat1A/g,significantratecapabilityof42%capacitanceretentionatanultrafastrateof50A/g,andoutstandinglong-termcyclingstabilityatvariouscurrentdensities.Theremarkableelectrochemicalperformanceofas-preparednanoporousCuSnanosphereselectrodehasbeenattributedtoitsuniquestructuresthatplaysakeyroleinprovidingshortionandelectrondiffusionpathways,facilitatediontransportandmoreactivesitesforelectrochemicalreactions.Thisworkshedsanewlightonthemetalsulfidesdesignphilosophy,anddemonstratesthatnanoporousCuSnanosphereselectrodeisapromisingcandidateforapplicationinhigh-performancesupercapacitors.
简介:Preparationofhierarchicallyporous,heteroatom-richnanostructuredcarbonsthroughgreenandscalableroutesplaysakeyroleforpracticalenergystorageapplications.Inthiswork,naturallyabundantlignocellulosicagriculturalwastewithhighinitialoxygencontent,hazelnutshells,werehydrothermallycarbonizedandconvertedintonanostructured‘hydrochar’.Environmentallybenignceramic/magnesiumoxide(MgO)templatingwasusedtointroduceporosityintothehydrochar.Electrochemicalperformanceoftheresultingmaterial(HM700)wasinvestigatedinaqueoussolutionsof1MH2SO4,6MKOHand1MNa2SO4,usingathree-electrodecell.HM700achievedahighspecificcapacitanceof323.2F/gin1MH2SO4(at1A/g,-0.3to0.9Vvs.Ag/AgCl)duetothecontributionsofoxygenheteroatoms(13.5wt%)tothetotalcapacitancebypseudo-capacitiveeffect.Moreover,amaximumenergydensityof11.1Wh/kgandamaximumpowerdensityof3686.2W/kgwereattainedforthesymmetricsupercapacitoremployingHM700aselectrodematerial(1MNa2SO4,E=2V),makingthedevicepromisingforgreensupercapacitorapplications.
简介:9to12,April,2018Suzhou,ChinaInternationalSymposiumseriesonHighPowerLaserScienceandEngineering,aimingatbringingtogetherworldwidescientistsandengineersworkingonhighpowerlaserandphysics,isheldeverytwoyearssince2014.Onbehalfofthe3rdInternationalSymposiumonHighPowerLaserScienceandEngineering(HPLSE2018),
简介:AkindofcircularringhighfrequencywidebandunderwateracoustictransducerisdevelopedbyusingtheLowQvalueandbroadbandcharacteristicsofthepiezoelectricitycompositematerial,andthedualmodecouplingisusedtobroadenthebandwidthofthetransducerbydoubleringstackingalongtheaxialdirection.Throughtheoreticalanalysisandsimulationcalculation,thegeometricdimensionsofthesensitivecomponentsaredetermined.Thepiezoelectriccompositeringsareprocessedandthenthestacksensitiveelementcanbemadebystackingtwopiezoelectriccompositeringswiththesameouterdiameteranddifferentthicknessinaxialdirectionbycuttingpiezoelectricceramicsfillingtheflexiblepolymer-coatingelectrode.Finally,thetransducercanbemadebypouringwaterproofsound-permeablelayer.Theperformancesoftransducerhavealsobeentestedinthewaterandthetestresultsshowthattheresonantfrequencyis410kHz,themaximumtransmitvoltageresponseis150dB,the-3dBbandwidthcanreaches60kHz,thehorizontaldirectivity(-5dB)is360°,andtheverticaldirectivity(-3dB)is20°.Itisalsoshownthatthebandwidthofthetransducercanbeenlargedremarkablybyusingthemethodofstackingtwodifferentthicknesspiezoelectriccompositeringsalongtheaxialdirection,andthehorizontalomnidirectionalemissionofacousticwavecanberealized
简介:Ininertialfusionenergy(IFE)research,aconsiderableattentionhasrecentlybeenfocusedontheissueoflargetargetfabricationforMJ-classlaserfacilities.Theignitionandhigh-gaintargetdesignsrequireacondenseduniformlayerofhydrogenfuelontheinsideofasphericalshell.Inthisreport,wediscussthecurrentstatusandfurthertrendsintheareaofdevelopingthelayeringtechniquesintendedtoproduceignition,andlayeringtechniquesproposedtohighrepetitionrateandmassproductionofIFEtargets.
简介:TheLaboratoryforIntenseLasers(L2I)isaresearchcentreinopticsandlasersdedicatedtoexperimentalresearchinhighintensitylaserscienceandtechnologyandlaserplasmainteraction.Currentlythelaboratoryisundergoinganupgradewiththegoalofincreasingtheversatilityofthelasersystemsavailabletotheusers,aswellasincreasingthepulserepetitionrate.Inthispaperwereviewthecurrentstatusofthelaserresearchanddevelopmentprogrammeofthisfacility,namelytheupgradedcapabilityandtherecentprogresstowardstheinstallationofanultrashort,diode-pumpedOPCPAlasersystem.
简介:ThisarticlefocusesonthedevelopmentofadiscontinuousGalerkin(DG)methodforsimulationsofmulticomponentandchemicallyreactingflows.Comparedtoaerodynamicflowapplications,inwhichDGmethodshavebeensuccessfullyemployed,DGsimulationsofchemicallyreactingflowsintroducechallengesthatarisefromflowunsteadiness,combustion,heatrelease,compressibilityeffects,shocks,andvariationsinthermodynamicproperties.Toaddressthesechallenges,algorithmsaredeveloped,includinganentropy-boundedDGmethod,anentropyresidualshockindicator,andanewformulationofartificialviscosity.TheperformanceandcapabilitiesoftheresultingDGmethodaredemonstratedinseveralrelevantapplications,includingshock/bubbleinteraction,turbulentcombustion,anddetonation.ItisconcludedthatthedevelopedDGmethodshowspromisingperformanceinapplicationtomulticomponentreactingflows.ThepaperconcludeswithadiscussionoffurtherresearchneedstoenabletheapplicationofDGmethodstomorecomplexreactingflows.
简介:Ametallicnanostructuredarraythatscattersradiationtowardathinmetalliclayergeneratessurfaceplasmonresonancesfornormallyincidentlight.Thelocationoftheminimumofthespectralreflectivityservestodetectchangesintheindexofrefractionofthemediumunderanalysis.Thenormalincidenceoperationeasesitsintegrationwithopticalfibers.Thegeometryofthearrangementandthematerialselectionarechangedtooptimizesomeperformanceparametersassensitivity,figureofmerit,fieldenhancement,andspectralwidth.Thisoptimizationtakesintoaccountthefeasibilityofthefabrication.Theevaluatedresultsofsensitivity(1020nm/RIU)andfigureofmerit(614RIU-1)arecompetitivewiththosepreviouslyreported.
简介:ThroughanisotropicAgovergrowthonthesurfaceofAunanobipyramids(AuNBPs),high-purityandsizecontrolledAgnanorods(Au/AgNRs)areobtainedbyasimplifiedpurificationprocess.ThediametersoftheAu/AgNRsaredeterminedbythesizeoftheas-preparedAuNBPs,andthelengthsoftheAu/AgNRsaretunableusingdifferentamountsofAgprecursorinthegrowthsolution.Surface-enhancedRamanscattering(SERS)studiesusingRhodamine-6G(R6G)asatestmoleculeindicatethattheAu/AgNRshaveexcellentsensingpotential.ThetunableopticalpropertiesandstrongelectromagneticeffectoftheAu/AgNRs,alongwiththeirsuperiorSERSsignalenhancement,showthatAu/AgNRsarepromisingforfurtherapplicationsinplasmonsensingandbiomoleculardetection.
简介:Opticalvorticesarestructuresoftheelectromagneticcarryingorbitalangularmomentum(OAM).Recently,high-orderharmonicgeneration(HHG),leadingtothefieldwithaspiralphaserampaboutapoint-phasesingularity,OAMhasbeenimprintedtoshort-wavelengthradiationthroughemissionofattosecondtwistedbeamsintheextreme-ultraviolet(XUV)regime.Weexplorethedetailsofthemappingofthedrivingvortextoitsharmonicspectrum.Inparticular,weshowthatthegeometryoftheharmonicvorticesisconvoluted,arisingfromthesuperpositionofthecontributionfromtheshortandlongquantumpathsresponsibleofHHG.Finally,weshowhowtotakeadvantageoftransversephase-matchingtoselecttwistedattosecondbeamswithdifferentspatiotemporalproperties.
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°.
简介:Flowbatterieswithhighenergydensityandlongcyclelifehavebeenpursuedtoadvancetheprogressofenergystorageandgridapplication.Non-aqueousbatterieswithwidevoltagewindowsrepresentapromisingtechnologywithoutthelimitationofwaterelectrolysis,buttheysufferfromlowelectrolyteconcentrationandunsatisfactorybatteryperformance.Here,anon-aqueouslithiumbrominerechargeablebatteryisproposed,whichisbasedonBr2/Br-andLi+/Liasactiveredoxpairs,withfastredoxkineticsandgoodstability.TheLi/Brbatterycombinestheadvantagesofhighoutputvoltage(3.1V),electrolyteconcentration(3.0mol/L),maximumpowerdensity(29.1mW/cm2)andpracticalenergydensity(232.6Wh/kg).Additionally,thebatterydisplaysacolumbicefficiency(CE)of90.0%,avoltageefficiency(VE)of88.0%andanenergyefficiency(EE)of80.0%at1.0mA/cm2aftercontinuouslyrunningformorethan1000cycles,whichisbyfarthelongestcyclelifereportedfornon-aqueousflowbatteries.
简介:Inthiswork,viaafacilesolvothermalroute,wesynthesizedananodematerialforlithiumionbatteries(LIBs)—SnS_2nanoparticle/graphene(SnS_2NP/GNs)nanocomposite.ThenanocompositeconsistsofSnS_2nanoparticleswithanaveragediameterof4nmandgraphenenanosheetswithoutrestacking.TheSnS_2nanoparticlesarefirmlyanchoredonthegraphenenanosheets.AsananodematerialforLIBs,thenanocompositeexhibitsgoodListorageperformanceespeciallyhighrateperformance.Atthehighcurrentrateof5,10,and20A/g,thenanocompositedeliveredhighcapacitiesof525,443,and378mAh/g,respectively.ThegoodconductivityofthegraphenenanosheetsandthesmallparticlesizeofSnS_2contributetotheelectrochemicalperformanceofSnS_2NP/GNs.
简介:Alloymaterialshaveattractedincreasingattentionsbecausetheypossesssuperiorelectricalconductivitywhichcancontributetoexcellentelectrochemicalperformance.HereinadendriticNi3Calloymaterialhasbeenpreparedbythepyrolysisofnickelacetylacetonateemployingoleylamineasareductantand1-octadeceneoroctadecaneasthesolvent.Thecurrent–voltagecurvesindicatingthattheelectricalconductivityofNi3Cishigherthanthatofnickeloxide.Electrochemicaltestingindicatesthatahighspecificcapacityof390C/gisfoundinalkalineelectrolyteat0.5A/g,anddeliverexcellentratecharacteristicaswellascyclelife.Theexcellentelectrochemicalperformancemaybeattributedtoitshighelectricalconductivityanddendriticnanostructurethatcanpromotediffusionofelectrolyteions.Inaddition,theAC//Ni3Casymmetricsupercapacitorhasbeenassembledatacellvoltagesbetween0and1.6V,achievingamaximumenergydensityof37Wh/kg(atapowerdensityof0.3995kW/kg),andthismanifeststhattheNi3Calloyisapromisingelectrodematerialforelectrochemicalenergystorage.