简介：Porousnanocarbonswithaverageparticlesize20–40nmweredevelopedusingbiowasteoilpalmleavesasaprecursor.Simplepyrolysiswascarriedoutat700°Cundernitrogenatmosphere.Obtainedporousnanocarbonsshowedexcellentporousnaturealongwithsphericalshape.Symmetricsupercapacitorfabricatedfromporousnanocarbonsshowedsuperiorsupercapacitanceperformancewherehighspecificcapacitanceof368F/gat0.06A/gin5MKOHwerereported.Italsoexhibitedhighstability(96%over1700cycles)andenergydensityof13Wh/kg.Lowresistancevalueswereobtainedbyfittingtheimpedancespectra,thusindicatingtheavailabilityofthesematerialsassupercapacitorselectrode.Thepresentedmethodiscosteffectiveandalsoinlinewithwastetowealthapproach.

简介：SG-ⅢlaserfacilityisnowthelargestlaserdriverforinertialconfinementfusionresearchinChina.Thewholelaserfacilitycandeliver180kJenergyand60TWpowerultravioletlaserontotarget,withpowerbalancebetterthan10%.WereviewthelasersystemandintroducetheSG-Ⅲlaserperformancehere.

简介：Inthispaper,flowreconstructionaccuracyandflowpredictioncapabilityofdiscontinuoustransonicflowfieldbymeansofproperorthogonaldecomposition(POD)methodisstudied.Althoughlinearsuperpositionof‘‘highfrequencywaves''indifferentPODmodescanachievethereconstructionoftheshockwave,thesmoothnessofthesolutionneartheshockwavecannotbeguaranteed.Themodalcoefficientsareinterpolatedorextrapolatedanddifferentmodalcomponentsaresuperposedtorealizethepredictionoftheflowfieldbeyondthesnapshotsets.Resultsshowthatcomparedwiththesubsonicflow,thetransonicflowwithshockwaverequiresmorePODmodestoreachacomparativereconstructionaccuracy.Whenashockwaveexists,theinterpolationpredictionabilityisacceptable.However,largeerrorsexistinextrapolation,andincreasingthenumberofPODmodescannoteffectivelyimprovethepredictionaccuracyoftheflowfield.

简介：Inordertounderstandthebreakupperformanceofcoaxialporousinjectors,thespraysofcoaxialporousinjectorswithtwodifferentporousmaterialcylinderlengthswerecomparedwiththoseofconventionalshearcoaxialinjectors.Toallowcomparison,thewallinjectionlengthsweredesignedtobeequivalenttothevalueoftherecessdepth.Coldflowsprayswerevisualizedusingback-litphotographymethodsandanalyzedquantitativelywithalaserdiffractionapparatus,inordertostudytheeffectsofthemomentumfluxratioandWebernumberonthebreakupforeachtypeofinjector.Incaseoftheshearcoaxialinjector,thelargeliquidcorewasobservedinlowairmassflowratecondition.However,thedestabilizationoftheliquidjetfromthecoaxialporousinjectorisalmostcompletewithintheinnerregion,neartheinjectorfaceplate.Additionally,betterbreakupperformanceinlowgasflowrateconditionwasobtainedwhentheporouscylinderlengthdecreased,whiletheshearcoaxialinjectorsshowedbetterbreakupefficiencywhentherecesslengthincreased.Inconclusion,thedifferentbreakupprocesscausedbytheradialmomentumintheinnerregionoftheporousinjectordisintegratedtheliquidcore.

简介：WereportonthetemporalcontrastperformanceofthePHELIXfacilityinviewoftherequirementsimposedbysolidtargetinteractionexperiments.Therequirementanalysisforthenanosecondandpicosecondtemporalcontrastisderivedfromempiricaldataandsimpletheoreticalmodeling,whiletherealizationshowsthatusinganultrafastopticalparametricamplifierandplasmamirrorsenablesmeetingthisspecification.

简介：Theeffectsofdifferentrefrigerantsonheattransferperformanceofpulsatingheatpipe(PHP)areinvestigatedexperimentally.Theworkingtemperatureofpulsatingheatpipeiskeptintherangeof20℃-50℃.Thestartuptimeofthepulsatingheatpipewithrefrigerantscanbeshorterthan4min,whenheatingpowerisintherangeof10W-100W.Thestartuptimedecreaseswithheatingpower.ThermalresistancesofPHPwithfillingratio20.55%wereobviouslylargerthanthosewithotherfillingratios.ThermalresistanceofthePHPwithR134aismuchsmallerthanthatwithR404AandR600a.ItindicatesthattheheattransferabilityofR134aisbetter.Inaddition,acorrelationtopredictthermalresistanceofPHPwithrefrigerantswassuggested.

简介：Theconceptofcombiningmetallichoneycombwithfoldedthinmetallicsheets(corrugation)toconstructanovelcoretypeforlightweightsandwichstructuresisproposed.Thehoneycomb–corrugationhybridcoreismanufacturedbyfillingtheintersticesofaluminumcorrugationswithprecision-cuttrapezoidalaluminumhoneycombblocks,bondedtogetherusingepoxyglue.Theperformanceofsuchhybrid-coredsandwichpanelssubjectedtoout-of-planecompression,transverseshear,andthree-pointbendingisinvestigated,bothexperimentallyandnumerically.Thestrengthandenergyabsorptionofthesandwicharedramaticallyenhanced,comparedtothoseofasandwichwitheitheremptycorrugationorhoneycombcore.Theenhancementisinducedbythebeneficialinteractioneffectsofhoneycombblocksandfoldedpanelsonimprovedbucklingresistanceaswellasalteredcrushingmodesatlargeplasticdeformation.Thepresentapproachprovidesaneffectivemethodtofurtherimprovethemechanicalpropertiesofconventionalhoneycomb-coredsandwichconstructionswithlowrelativedensities.

简介：Fuelcellsandelectrolysisarepromisingcandidatesforfutureenergyproductionfromrenewableenergysources.Usually,polymerelectrolytefuelcellsystemsrunonhydrogenandair,whilethemostofelectrolysissystemsventoutoxygenasunusedby-product.Replacingairwithpureoxygen,fuelcellelectrochemicalperformance,durabilityandsystemefficiencycanbesignificantlyincreasedwithafurtheroverallsystemsimplificationandincreasedreliability.Thiswork,whichrepresentstheinitialstepforpureH2/O2polymerelectrolytefuelcelloperationinclosed-loopsystems,focusesonperformancevalidationofasinglecelloperatingwithpureH2/O2underdifferentrelativehumidity（RH）levels,reactantsstoichiometryconditionsandtemperature.Asaresultofthisstudy,themostconvenientandappropriateoperativeconditionsforapolymerelectrolytefuelcellstackintegratedinaclosedloopsystemwereselected.

简介：Wecomprehensivelycharacterizethetransmissionperformanceofm-aryquadratureamplitudemodulation（m-QAM）signalsthroughasiliconmicroringresonatorintheexperiment.Usingorthogonalfrequency-divisionmultiplexingbasedonoffsetQAM（OFDM/OQAM）whichismodulatedwithm-QAMmodulations,wedemonstratelow-penaltydatatransmissionofOFDM/OQAM64-QAM,128-QAM,256-QAM,and512-QAMsignalsinasiliconmicroringresonator.Theobservedopticalsignal-to-noiseratio（OSNR）penaltiesare1.7dBfor64-QAM,1.7dBfor128-QAM,and3.1dBfor256-QAMatabit-errorrate（BER）of2×10-3and3.3dBfor512-QAMataBERof2×10-2.Theperformancedegradationduetothewavelengthdetuningfromthemicroringresonanceisevaluated,showingawavelengthrangeof0.48nmwithBERbelow2×10-3.Moreover,wedemonstratedatatransmissionof191.2-Gbit/ssimultaneouseightwavelengthchannelOFDM/OQAM256-QAMsignalsinasiliconmicroringresonator,achievingOSNRpenaltieslessthan2dBataBERof2×10-2.

简介：Increasingtheaerodynamicloadoncompressorbladeshelpstoobtainahigherpressureratioinlowerrotationalspeeds.Consideringthehighaerodynamicloadeffectsandstructuralconcernsinthedesignprocess,itispossibletoobtainhigherpressureratioscomparedtoconventionalcompressors.However,itmustbenotedthatimposinghigheraerodynamicloadsresultsinhigherlosscoefficientsanddeterioratestheoverallperformance.Toavoidthelossincrease,theboundarylayerqualitymustbestudiedcarefullyoverthebladesuctionsurface.Employmentofadvancedshapedairfoils(likeCDAs),slottedbladesorotherboundarylayercontrolmethodshashelpedthedesignerstousehigheraerodynamicloadsoncompressorblades.Tandemcascadeisapassiveboundarylayercontrolmethod,whichisbasedonusingtheflowmomentumtocontroltheboundarylayeronthesuctionsurfaceandalsotoavoidtheprobableseparationcausedbyhigheraerodynamicloads.Infact,thefrontpressuresideflowmomentumhelpstocompensatethepositivepressuregradientovertheaftblade’ssuctionside.Also,incomparisontothesinglebladestators,tandemvariablestatorshavemoredegreesoffreedom,andthisissueincreasesthepossibilityoffindingenhancedconditionsinthecompressoroff-designperformance.Inthecurrentstudy,a3Ddesignprocedureforanaxialflowtandemcompressorstagehasbeenappliedtodesignahighlyloadedstage.Following,thisdesignisnumericallyinvestigatedusingaCFDcodeandthestagecharacteristicmapisreported.Also,theeffectofvariousstatorstaggeranglesonthecompressorperformanceandespeciallyonthecompressorsurgemarginhasbeendiscussed.TovalidatetheCFDmethod,anotherknowncompressorstageispresentedanditsperformanceisnumericallyinvestigatedandtheresultsarecomparedwithavailableexperimentalresults.

简介：

简介：Carbonclothmodifiedbyhydrothermaltreatmentinammoniawaterisdevelopedasthepositiveelectrodewithhighelectrochemicalperformanceforvanadiumredoxflowbatteries.TheSEMshowsthatthetreatmenthasnoobviousinfluenceonthemorphologyofcarboncloth.XPSmeasurementsindicatethatthenitrogenousfunctionalgroupscanbeintroducedonthesurfaceofcarbonclothsuccessfully.TheelectrochemicalperformanceofV（IV）/V（V）redoxcoupleonthepreparedelectrodeisevaluatedwithcyclicvoltammetryandlinearsweepvoltammetrymeasurements.TheN-dopedcarbonclothexhibitsoutstandingelectrochemicalactivityandreversibilitytowardV（IV）/V（V）redoxcouple.TherateconstantofV（IV）/V（V）redoxreactiononcarbonclothcanincreaseto2.27×10-4cm/sfrom1.47×10-4cm/safternitrogendoping.ThecellusingN-dopedcarbonclothaspositiveelectrodehaslargerdischargecapacityandhigherenergyefficiencycomparedwiththecellusingpristinecarboncloth.TheaverageenergyefficiencyofthecellusingN-dopedcarbonclothfor50cyclesat30mA/cm2is87.8%,4.3%largerthanthatofthecellusingpristinecarboncloth.ItindicatesthattheN-dopedcarbonclothhasapromiseapplicationprospectinvanadiumredoxflowbatteries.

简介：WehavedevelopedaSi/grapheneoxideelectrodesynthesizedviaultrasonication-stirringmethodunderalkalinecondition.Scanningelectronmicroscopy(SEM),transmissionelectronmicroscope(TEM),EDSdot-mappingandhigh-resolutiontransmissionelectronmicroscopy(HRTEM)resultsshowthatSiparticlesareevenlydispersedonthegrapheneoxidesheets.Theelectrochemicalperformancewasinvestigatedbygalvanostaticcharge/dischargetestsatroomtemperature.TheresultsrevealedthatSi/grapheneoxideelectrodeexhibitedahighreversiblecapacityof2825mAh/gwithacoulombicefficiencyof94.6%at100mA/gafter15cyclesandacapacityretentionof70.8%after105cyclesat4000mA/g.Theseperformanceparametersshowagreatpotentialinthehigh-performancebatteriesapplicationforportableelectronics,electricvehiclesandrenewableenergystorage.

简介：Carbonsurfacewithlargeoxygenandcarbonratio(O/C)indicatedanoutstandingelectro-catalyticactivitytowardL-ascorbicacidoxidation,comparedtoplatinumgroupmetals.However,interrelationofsurfacefunctionalgroupsanditselectro-catalyticactivityisstillunclear.Inthispaper,weprepareddifferentlevelsofoxidizedcarbonsbyasimpleacidtreatmentandinvestigatedthecorrelationbetweenthesurfaceoxygenfunctionalgroupsofacid-treatedcarbonandelectro-catalyticactivityinanelectrooxidationofL-ascorbicacid.Positivelychargedcarbonwasdemonstratedbylonepairelectronofoxygenfromvalencebandspectrastudy.Itwasrevealedthatthepositivelychargedcarbon,especiallyinvolvedincarbonyl,showedenhancedtheelectro-catalyticactivitythroughbothbetteradsorptionofnegativelychargedreactantsandloweredLUMObyelectronegativityofoxygen.

简介：Nickelhydroxidewasusedasthepositiveelectrodematerialinrechargeablealkalinebatteries,whichplaysasignificantroleinthefieldofelectricenergystoragedevices.β-nickelhydroxide(β-Ni(OH)_2)waspreparedfromnickelsulphatesolutionusingpotassiumhydroxideasaprecipitatingagent.Pureβ-phaseofnickelhydroxidewasconfirmedfromXRDandFT-IRstudies.TheeffectsofTiO_2additiveontheβ-Ni(OH)_2electrodeperformanceareexamined.ThestructureandpropertyoftheTiO_2addedβ-Ni(OH)_2werecharacterizedbyXRD,TG-DTAandSEManalysis.Apasted–typeelectrodeispreparedusingnickelhydroxidepowderasthemainactivematerialonanickelsheetasacurrentcollector.Cyclicvoltammetryandelectrochemicalimpedancespectroscopystudieswereperformedtoevaluatetheelectrochemicalperformanceoftheβ-Ni(OH)_2andTiO_2addedβ-Ni(OH)_2electrodesin6MKOHelectrolyte.Anodic(Epa)andcathodic(Epc)peakpotentialsarefoundtodecreaseaftertheadditionofTiO2intoβ-Ni(OH)_2electrodematerial.Further,additionofTiO_2isfoundtoenhancethereversibilityoftheelectrodereactionandalsoincreasetheseparationoftheoxidationcurrentpeakoftheactivematerialfromtheoxygenevolutioncurrent.Comparedwithpureβ-Ni(OH)_2lectrode,TiO_2addedβ-Ni(OH)_2electrodeisfoundtoexhibithigherprotondiffusioncoefficient(D)andlowerchargetransferresistance.ThesefindingssuggestthattheTiO_2addedβ-Ni(OH)_2electrodepossessimprovedelectrochemicalpropertiesandthuscanberecognizedasapromisingcandidateforthebatteryelectrodeapplications.

简介：NativedefectsinHfSiO_4areinvestigatedbyfirstprinciplescalculations.TransitionlevelsofnativedefectscanbeaccuratelydescribedbyemployingthenonlocalHSE06hybridfunctional.Thismethodologyovercomesthebandgapproblemintraditionalfunctionals.BybandalignmentsamongtheSi,GaAsandHfSiO_4,weareabletodeterminethepositionofdefectlevelsinSiandGaAsrelativetotheHfSiOibandgap.Weevaluatethepossibilityofthesedefectsactingasfixedcharge.Nativedefectsleadtothechangeofvalenceandconductionbandoffsets.Gateleakagecurrentisevaluatedbythebandoffset.Inaddition,wealsoinvestigatediffusionsofnativedefects,anddiscusshowtheyaffecttheMOSdeviceperformance.

简介：Cu2ZnSnS4(CZTS)基于太阳能电池被microelectronic和photonic结构(AMPS-1D)的一个维的太阳能电池模拟软件分析数字地模仿。在模拟使用的设备结构是Al/ZnO:Al/nZn(O，S)/pCZTS/Mo。工作是在ZnO1xSx缓冲区层，它将产出更高的变换效率。由改变S/(S+O)比率x，在CZTS/Zn的传导乐队偏移量(CBO)(O，S)如果比率的完整的范围被考虑，接口能从0.23eV到1.06eV。当时，0.23eV的最佳的CBO能被完成ZnO1xSx缓冲区有S/(S+O)0.6的比率。太阳能电池效率首先与增加硫内容增加然后为x突然地减少>0.6，它由我们的建议的最佳的硫内容x=到达17.55%的最高的价值0.6。我们的结果在处理ZnO1x为高效率CZTS的Sx缓冲区层免职太阳能电池。

简介：ActivatedcarbonsforelectrochemicalcapacitorelectrodesarepreparedfromsoyabeanusingchemicalactivationwithKOH.TheporesizeiseasilycontrollablebychangingthemassratiobetweenKOHandcarbonizedproduct.Theas-preparedmaterialspossessalargespecificsurfacearea,uniquestructure,well-developedhierarchicalporosityandplentifulheteroatoms(mainlyOandN).Thusresultedinitshighspecificcapacitance,goodratecapacityandcyclingstability.Moreover,attributingtoworldwideavailability,renewablenatureandlow-cost,activatedcarbonpreparedfromsoyabeanhasagoodpotentialinenergyconversionandstoragedevices.

简介：

简介：Light-emittingdiode（LED）-basedvisiblelightcommunication（VLC）hasbecomeapotentialcandidatefornextgenerationultra-high-speedindoorwirelesscommunication.Inthispaper,fourspecial-shaped8-quadratureamplitudemodulation（QAM）constellationsareinvestigatedinasingle-carrierVLCsystem.Itisnumericallyverifiedandexperimentallydemonstratedthatcircular（7,1）showsobvioussuperiorityintheperformanceofthedynamicrangeofsignalvoltagepeak-to-peak（vpp）valueandbiterrorrate（BER）.Nextbestisrectangular,followedbytriangular;circular（4,4）hastheworstperformance.Adatarateof1.515Gbit/sissuccessfullyachievedbycircular（7,1）employingaredchipLEDover0.5mindoorfreespacetransmissionbelowaBERthresholdof3.8×10-3.Comparedwithcircular（4,4）,thetraditional8-QAMconstellation,circular（7,1）providesawiderdynamicrangeofsignalvpp,ahigherdatarate,andalongertransmissiondistance.Tothebestofourknowledge,thisisthefirstinvestigationintotheperformancedifferencesofspecial-shaped8-QAMconstellationsinahighspeed,single-carrierVLCsystem,andtheresultscomprehensivelydemonstratethatcircular（7,1）istheoptimaloption.