简介：Inordertosolvethemagneto-hydrodyna-mics(MHD)problems,itisneccessarytocombineMaxwell'sequationswithfluidmechanicsequations.But,underthefirstorderapproximationthemasspointmotivationequationsandelectromagneticbasiclawsare

简介：Inlostpaperofmagneto-hydrodynamicinstabilityanalysisofliquidmetalfreesurfacejetflow(PartⅠ),themagneto-hydrodynamicinstabilitywasanalyzedforthejetflowinatransversenon-uniformmagneticfield,BT.But,asallknown,fortherealconditionsofliquidmetallimiter-divertorplasma-facingcomponentsareintoroidalandpoloidalfields.So,wetrytoanalyzethemagneto-hydrodynamicinstabilityofthejetflow(herebyonlyforcircularshapecrosssectionjetflow)inthezoneofnon-uniformmagneticfields,

简介：Theaerobicoxidationofglycerolprovidesaneconomicallyviableroutetoglyceraldehyde,dihydroxyacetoneandglycericacidwithversatileapplications,forwhichmonometallicPt,AuandPdandbimetallicAu–Pt,Au–PdandPt–PdcatalystsonTiO2wereexaminedunderbase-freeconditions.PtexhibitedasuperioractivityrelativetoPd,andAu–PdandPt–PdwhileAuwasessentiallyinactive.ThepresenceofAuontheAu–Pt/TiO2catalystsledtotheirhigheractivities(normalizedperPtatom)inawiderangeofAu/Ptatomicratios(i.e.1/3–7/1),andtheonewiththeAu/Ptratioof3/1exhibitedthehighestactivity.SuchpromotingeffectisascribedtotheincreasedelectrondensityonPtviatheelectrontransferfromAutoPt,ascharacterizedbythetemperature-programmeddesorptionofCOandinfra-redspectroscopyforCOadsorption.Meanwhile,thepresenceofAuonAu–Pt/TiO2,mostlikeduetotheobservedelectrontransfer,changedtheproductselectivity,andfacilitatedtheoxidationofthesecondaryhydroxylgroupsinglycerol,leadingtothefavorableformationofdihydroxyacetoneoverglyceraldehydeandglycericacidthatwerederivedfromtheoxidationoftheprimaryhydroxylgroups.ThesynergeticeffectbetweenAuandPtdemonstratesthefeasibilityintheefficientoxidationofglyceroltothetargetedproducts,forexample,byrationaltuningoftheelectronicpropertiesofmetalcatalysts.

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简介：Therealizationofanefficientopticalsensorbasedonaphotoniccrystalmetasurfacesupportingboundstatesinthecontinuumisreported.Liquidswithdifferentrefractiveindices,rangingfrom1.4000to1.4480,areinfiltratedinamicrofluidicchamberbondedtothesensingdielectricmetasurface.Abulkliquidsensitivityof178nm/RIUisachieved,whileaQ-factorofabout2000givesasensorfigureofmeritupto445inairatbothvisibleandinfraredexcitations.Furthermore,thedetectionofultralow-molecular-weight（186Da）moleculesisdemon-stratedwitharecordresonanceshiftof6nmperlessthanaInmthicksinglemolecularlayer.Thesystemexploitsanormal-to-the-surfaceopticallaunchingscheme,withexcellentinterrogationstabilityanddemonstratesalignment-freeperformances,overcomingthelimitsofstandardphotoniccrystalsandplasmonicresonantconfigurations.

简介：我们导出通过和事件激光领域，射出的光子，和磁性的wiggler在在第一免费电子的激光(FEL)作为使不安的唯一的zeroth顺序扮演古典地的磁性的wiggler生产的一个轴的静电的领域的一个电子的三量的相互作用散布的生气的节。在推导，我们使用量摆动electrodynamics(QWD)。我们发现这散布支配平常的二量的散布。由三量的散布稀释的上述静电的领域驾驶的自发的免费电子的二量的空排放的输出力量在第一FEL的情况中与测量力量在10的一个因素以内同意。

简介：Afree-standingpaper-likethree-dimensionalgrapheneframework(3DGF)withorientatedlaminarstructureandinterconnectedmacropores,wasobtainedbythehardtemplate-directedorderedassembly.Asthesacrificialtemplates,polystyrene(PS)latexsphereswereassembledwithgrapheneoxide(GO)tobuildupasandwichtypecompositefilm,followedbyheatremovalofwhichwithasimultaneousreductionofGO.The3DGFexhibitedhighspecificsurfaceareaof402.5m2/g,controllableporesandmechanicalflexibility,whichwasemployedasthebinder-freesupercapacitorelectrodeandshowshighspecificgravimetriccapacitanceof95F/gat0.5A/g,withenhancedratecapabilityin3electrodeKOHsystem.

简介：FERMI,theseededfreeelectronlaser(FEL)inoperationinItaly,isprovidingtheUserCommunitywithuniquefullycoherentradiation,inthewavelengthrange100–4nm.FERMIisthefirstFELfullysynchronizedbymeansofopticalfibers.Theopticaltimingsystemensuresanultra-stablephasereferencetoitsdistributedclients.Severalfemtosecondlongitudinaldiagnosticsverifytheachievedperformance;thebunchlengthmonitor(BLM)andthebuncharrivalmonitor(BAM)willbepresentedinthispaper.Feedbacksystemsplayacrucialroletoguaranteetheneededlongtermelectronbeamstability.Areal-timeinfrastructureallowsshot-to-shotcommunicationbetweenfront-endcomputersandtheservers.Orbitfeedbacksareusefulinmachinetuning,whereaslongitudinalfeedbackscontrolelectronenergy,compressionandarrivaltime.Aflexiblesoftwareframeworkallowsarapidimplementationofheterogeneousmultiinput–multi-output(MIMO)longitudinalloopssimplybyselectingtheappropriatesensorsandactuators.

简介：Forthefirsttime,WO2.72nanowireswerein-situgrownoncarbonclothbyasimplesolvothermalreaction.ThenanowireWO2.72/carboncloth(NWWO2.72/CC)electrodeshowedgoodelectrochemicalperformancewithspecificcapacitance(Cs)reachingupto398Fg-1atacurrentdensityof2Ag-1.Thecapacitanceof240Fg-1wasretainedatahighcurrentdensityof16Ag-1.Tofurtherevaluatetheenergystorageperformance,flexibleasymmetricsupercapacitors(FASCs)werefabricatedusingtheactivatedcarbon/carboncloth(AC/CC)asnegativeelectrodeandNWWO2.72/CCaspositiveelectrode,respectively.TheFASCsdeliveredahighenergydensityof28Whkg-1atapowerdensityof745Wkg-1and13Whkg-1evenatahighpowerdensityof22.5kWkg-1.Moreimpressively,81%ofthespecificcapacitanceoftheFASCswasretainedafter10,000cycles,indicatingexcellentcyclestability.ThisworkindicatestheNWWO2.72/CCholdsagreatpotentialforapplicationinenergystoragedevices.

简介：Oxygen-andnitrogen-functionalizedcarbonnanotubes(OCNTsandNCNTs)wereappliedasmetal-freecatalystsinselectiveolefinhydrogenation.AseriesofNCNTswassynthesizedbyNH3post-treatmentofOCNTs.Temperature-programmeddesorption,N2physisorption,Ramanspectroscopy,high-resolutiontransmissionelectronmicroscopyandX-rayphotoelectronspectroscopywereemployedtocharacterizethesurfacepropertiesofOCNTsandNCNTs,aimingatadetailedanalysisofthetypeandamountofoxygenandnitrogen-containinggroupsaswellassurfacedefects.Thegas-phasetreatmentsappliedforoxygenandnitrogenfunctionalizationatelevatedtemperaturesupto600Cledtotheincreaseofsurfacedefects,butdidnotcausestructuraldamagesinthebulk.NCNTsshowedaclearlyhigheractivitythanthepristineCNTsandOCNTsinthehydrogenationof1,5-cyclooctadiene,andalsotheselectivitytocyclooctenewashigher.Thefavorablecatalyticpropertiesareascribedtothenitrogen-containingsurfacefunctionalgroupsaswellassurfacedefectsrelatedtonitrogenspecies.Incontrast,oxygen-containingsurfacegroupsandthesurfacedefectscausedbyoxygenspeciesdidnotshowclearcontributiontothehydrogenationcatalysis.

简介：Wepresentanovelandsimplemethodtoobtainanultrawidefreespectralrange(FSR)siliconringresonatortogetherwithatuningrangecoveringtheentirespectrumfrom1500to1600nm.AringresonatorwithalargeFSRtogetherwithahighQfactor,hightuningefficiency,andlowfabricationcostandcomplexityisdesiredformanyapplications.Inthispaper,weintroduceanovelwaytomakesucharingresonator,whichtakesadvantageofthewell-knownresonance-splittingphenomenon.ItisasingleringresonatorwithanFSRofmorethan150nmaround1550nmandwhichhasaneasythermo-optictunabilitythatcanproduceatuningrangearound90nmorevenmore.Moreover,thedeviceissimpletoimplementandcanbefabricatedinstandardcomplementarymetal-oxidesemiconductortechnologywithoutrequiringanykindofcomplicatedprocessingorextramaterials.Thepotentialapplicationsincludesinglemodelasercavities,wavelengthdivisionmultiplexingfilters,(de)multiplexers,opticalsensors,andintegratedreflectors.

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简介：ThestatusoftheEuropeanX-rayFree-ElectronLaser(EuropeanXFEL),underconstructionnearHamburg,Germany,isdescribed.ThestartofoperationsoftheLCLSatSLACandofSACLAinJapanhasalreadyproducedimpressivescientificresults.TheEuropeanXFELfacilityispoweredbya17.5GeVsuperconductinglinearacceleratorthat,comparedtothesetwooperatingfacilities,willgeneratetwoordersofmagnitudemorepulsespersecond,upto27000.Itcanthereforesupportmodesofoperationswitchingthebeamupto30timespersecondamongthreedifferentexperiments,providingeachofthemwiththousandsofpulsespersecond.Thescientificpossibilitiesopenedupbythesecapabilitiesarebrieflydescribed,togetherwiththecurrentinstrumentaldevelopments(inoptics,detectors,lasers,etc.)thatarenecessarytoimplementthisprogram.

简介：Afullycoherentfreeelectronlaser(FEL)seededwithahigher-orderharmonic(HH)pulsefromhigh-orderharmonicgeneration(HHG)issuccessfullyoperatedforasufficientlyprolongedtimeinpilotuserexperimentsbyusingatimingdriftfeedback.ForHHG-seededFELs,theseedinglaserpulseshavetobesynchronizedwithelectronbunches.DespiteseededFELsbeingnon-chaoticlightsourcesinprinciple,externallaser-seededFELsareoftenunstableinpracticebecauseofatimingjitterandadriftbetweentheseedinglaserpulsesandtheacceleratedelectronbunches.Accordingly,weconstructedarelativearrival-timingmonitorbasedonnon-invasiveelectro-opticsampling(EOS).TheEOSmonitormadeuninterruptedshot-to-shotmonitoringpossibleevenduringtheseededFELoperation.TheEOSsystemwasthenusedforarrival-timingfeedbackwithanadjustabilityof100fsforcontinualoperationoftheHHG-seededFEL.UsingtheEOS-basedbeamdriftcontrollingsystem,theHHG-seededFELwasoperatedoverhalfadaywithaneffectivehitrateof20%–30%.Theoutputpulseenergywas20μJatthe61.2nmwavelength.TowardsseededFELsinthewaterwindowregion,weinvestigatedourupgradeplantoseedhigh-powerFELswithHHphotonenergyof30–100eVandlaseatshorterwavelengthsofupto2nmthroughhigh-gainharmonicgeneration(HGHG)attheenergy-upgradedSPring-8CompactSASESource(SCSS)accelerator.WestudiedabenefitaswellasthefeasibilityofthenextHHG-seededFELmachinewithsingle-stageHGHGwithtunabilityofalasingwavelength.

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简介：HydrotalciteprecursorsofLamodifiedNi-Al2O3andNi-SiO2catalystspreparedbyco-precipitationmethodandthecatalyticactivitieswereexaminedfortheproductionofCOx-freeH2byCH4decomposition.Physico-chemicalcharacteristicsoffresh,reducedandusedcatalystswereevaluatedbyXRD,TPRandO2pulsechemisorptions,TEMandBET-SAtechniques.XRDstudiesshowedphasesduetohydrotalcite-likeprecursorsinovendriedformproduceddispersedNiOspeciesuponcalcinationinstaticairabove450C.Ramanspectraofdeactivatedsamplesrevealedthepresenceofbothorderedanddisorderedformsofcarbon.Ni-La-Al2O3catalystwithamoleratioofNi:La:Al=2:0.1:0.9exhibitedtremendouslyhighlongevitywithahydrogenproductionrateof1300molH2mol1Ni.AdirectrelationshipbetweenNimetalsurfaceareaandhydrogenyieldswasestablished.