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简介：Variousindexstructureshaverecentlybeenproposedtofacilitatehigh-dimensionalKNNqueries,amongwhichthetechniquesofapproximatevectorpresentationandone-dimensional(1D)transformationcanbreakthecurseofdimensionality.Basedonthetwotechniquesabove,anovelhigh-dimensionalindexisproposed,calledBit-codeandDistancebasedindex(BD).BDisbasedonaspecialpartitioningstrategywhichisoptimizedforhigh-dimensionaldata.Bythedefinitionsofbitcodeandtransformationfunction,ahigh-dimensionalvectorcanbefirstapproximatelyrepresentedandthentransformedintoa1Dvector,thekeymanagedbyaB+-tree.AnewKNNsearchalgorithmisalsoproposedthatexploitsthebitcodeanddistancetoprunethesearchspacemoreeffectively.ResultsofextensiveexperimentsusingbothsyntheticandrealdatademonstratedthatBDout-performstheexistingindexstructuresforKNNsearchinhigh-dimensionalspaces.

简介：Thispaperpresentsanexperimentalstudyofthethree-dimensionalturbulentflowfieldsinalowspeedannularcascadeofhighturningangleturbineblades.Detailedmeasurementswereperformedonthebladesurfacesandmid-streamsurfaceinthepassageandatthreeaxialplanesdownstreamofthecascadebyusingwallstaticpressuretaps,afive-holeprobeandahot-wireanemometer,Thetestdataincludestaticpressuredistributiononbladesurfaces,totalpressurelosscofeeicient,meanflowvelocitycomponents.radialflowangle,turbulenceintensityandReynoldsshearstress.Analysesofthethree-dimensionalcascadeflowcharacteristicsweremadeonthenosetlocationofhighlossvortices.thevariationofpressuregradientinsidethecascadepassageandthepropertiesofendwallboundarylayerstotalpressurelossdistributions,secondaryvortexturbulentdissipationandwakedecaydowntreamofthecascade.Theseexperimentalresultsarevaluableforrevealingthedetailsofthecomplexvortexflowstructureinmodernhighlyloadedaxialturbomachinesandvalidatingthethree-dimensionalflownumericalcomputationcodes.

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：Weinvestigatethediffractionoftheguidedmodesofadielectricslabwaveguideonasimpleintegratedstructureconsistingofasingledielectricridgeonthesurfaceofthewaveguide.Numericalsimulationsbasedonaperiodicrigorouscoupled-waveanalysisdemonstratetheexistenceofsharpresonantfeaturesandboundstatesinthecontinuum(BICs)inthereflectanceandtransmittancespectraoccurringattheobliqueincidenceofatransverseelectric(TE)-polarizedguidedmodeontheridge.Usingtheeffectiveindexmethod,weexplaintheresonancesbytheexcitationofcross-polarizedmodesoftheridge.FormationoftheBICsareconfirmedusingatheoreticalmodelbasedoncoupled-wavetheory.ThemodelsuggeststhattheBICsoccurduetothecouplingofquasi-TEandquasi-transverse-magneticmodesofthestructure.SimpleanalyticalexpressionsfortheangleofincidenceandtheridgewidthpredictingthelocationoftheBICsareobtained.Theexistenceofhigh-QresonancesandBICsenablesusingtheconsideredintegratedstructureforsensing,transformationofopticalsignals,andenhancingnonlinearlight–matterinteractions.DuetotheLorentzianlineshapeoftheresonancesneartheBICs,thestructureisalsopromisingforfilteringapplications.

简介：快打扫方法的高顺序最近在文学被开发了高效地解决静态的Hamilton-Jacobi方程。与快打扫方法的第一份订单作比较，快大规模的高顺序方法是更精确的，但是因为精确地在流入边界附近对待点是特别地重要的更宽的数字模板，他们经常在边界附近为几个格子点要求另外的数字边界处理，当信息将流进计算领域并且将影响全球精确性。在文学，在这些边界点的数字答案也与准确答案被修理，它不总是是可行的，或与第一顺序discretization计算了，它能减少全球精确性。在这篇论文，我们讨论二策略处理流入边界条件。一个人基于快在边界和理查森推测附近与几种不同网孔尺寸打扫方法的第一份订单的数字答案，其它基于一个Lax-Wendroff类型过程到反复利用PDE以正切的衍生物给正常写空间衍生物到流入边界，从而在格子获得高顺序解决方案值指在流入边界附近。我们用快大规模高度探索这二条途径顺序WENO计划在[18]为作为一个代表性的例子解决静态的Eikonal方程。数字例子被给表明这二条途径的表演。

简介：Combustioncharacteristicsofmethanejetflamesinanindustrialburnerworkinginhightemperaturecombustionregimewereinvestigatedexperimentallyandnumericallytoclarifytheeffectsofswirlinghightemperatureaironcombustion.Speziale-Sarkar-Gatski(SSG)Reynoldsstressmodel,Eddy-DissipationModel(EDM),DiscreteOrdinatesMethod(DTM)combinedwithWeighted-Sum-of-GreyGasesModel(WSGG)wereemployedforthenumericalsimulation.BothThermal-NOandPrompt-NOmechanismwereconsideredtoevaluatetheNOformation.Temperaturedistribution,NOemissionsbyexperimentandcomputationinswirlingandnon-swirlingpatternsshowcombustioncharacteristicsofmethanejetflamesaretotallydifferent.Non-swirlinghightemperatureairmadehighNOformationwhilesignificantNOprohibitionwereachievedbyswirlinghightemperatureair.Furthermore,velocityfields,dimensionlessmajorspeciesmolefractiondistributionsandThermal-NOmolarreactionrateprofilesbycomputationinterpretaninnerexhaustgasrecirculationformedinthecombustionzoneinswirlingcase.

简介：Supersonicmolecularbeaminjection(SMBI)wasfirstproposedanddemonstratedontheHL-1tokamak,wassuccessfullydevelopedandusedontheHL-1Mtokamak,andwasthenappliedontheHT-7superconductingtokamak,theToreSupratokamakandtheWT-ASstellarator.Withthenew

简介：Wereportonasystematicexperimentalstudyonthefluorescencespectraproducedfromafemtosecondlaserfilamentinairunderahighelectricfield.Theelectricfieldalonewasstrongenoughtocreatecoronadischarge(CD).Fluorescencespectrafromneutralandionicairmoleculesweremeasuredandcomparedwithpurehigh-voltageCDandpurelaserfilamentation(FIL).Amongthem,highelectricfieldassistedlaserFILproducednitrogenfluorescencemoreefficientlythaneitherpureCDorpureFILprocesses.Thenonlinearenhancementoffluorescencefromtheinteractionofthelaserfilamentandcoronadischargingelectricfieldresultedinamoreefficientionizationalongthelaserfilamentzone,whichwasconfirmedbythespectroscopicmeasurementofbothionization-inducedfluorescenceandplasma-scattered800nmlaserpulses.Thisisbelievedtobethekeyprecursorprocessforfilament-guideddischarge.

简介：ErrorestimatesofGalerkinmethodforKuramoto-Sivashingsky(K-S)equationinspacedimension≥3arederivedinthepaper.Theseresultsfurnishstrongevidenceforthecom-putationofthesolutions.

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简介：Thispaperdescribesanoverviewofourrecentdiscovery–cleardemonstrationthatLiFcrystalscanbeefficientlyusedasahigh-performanceneutronimagingdetectorbasedonopticallystimulatedluminescenceofcolorcentersgeneratedbyneutronirradiation.Itisshownthattheneutronimageswehaveobtainedarealmostfreefromgranularnoise,haveaspatialresolutionof～5.4μmandalinearresponsewithadynamicrangeofatleast103.ThehighcontrastandgoodsensitivityofLiFcrystalsallowustodistinguishtwoholeswithlessthan2%transmittancedifference.Weproposetousesuchdetectorsinareaswherehighspatialresolutionwithhighimagegradationresolutionisneeded,includingdiagnosticsofdifferentplasmasourcessuchaslaserandz-pinchproducedplasmas.

简介：Inthepreviouspapers,ahighperformancesparsestaticsolverwithtwo-levelunrollingbasedonacell-sparsestorageschemewasreported.Althoughthesolverreachesquiteahighefficiencyforabigpercentageoffiniteelementanalysisbenchmarktests,theMFLOPS(millionfloatingoperationspersecond)ofLDLTfactorizationofbenchmarktestsvaryonaDellPentiumⅣ850MHzmachinefrom100to456dependingontheaveragesizeofthesuper-equations,i.e.,ontheaveragedepthofunrolling.Inthispaper,anewsparsestaticsolverwithtwo-levelunrollingthatemploystheconceptofmaster-equationsandsearchesforanappropriatedepthsofunrollingisproposed.ThenewsolverprovideshigherMFLOPSforLDLTfactorizationofbenchmarktests,andthereforespeedsupthesolutionprocess.

简介：Afiniteelementisestablishedforanalyzingthedynamicalmechanicsanddeformationofsteelframeathightemperaturewhenitisrapidlycooleddownbyspraywaterinfirefighting.Thesimulationresultshowsthatremarkablemechanicalcouplingeffectsareproducedintheprocess,andthesectionalstressinrapidcoolingdownisfoundconsiderablylargerthanthatinheating-up.Meanwhile,thestressanddeformationofabeammainlyrelatedtocoolingrateandlocationaremuchlargerthanthoseofacolumninrapidcooling.Infirefighting,thestructureonthefirstorsecondfloorwasmoredangerousthanthoseonotherfloorsinrapidcooling.Theseresultscouldprovideatheoreticalreferenceforthedesignofsteelstructureandfirefighting.

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：TwoEu(Ⅲ)complexes,(tris-4,4,4-trifluoro-1-phenyl-1,3-butanedione)(1,10-phenanthroline)europium(Ⅲ)[Eu(tpb-H)3(phen)]and(tris-4,4,4-trifluoro-1-phenyl-1,3-butanedione)(2,2'-bipyridine)europium(Ⅲ)[Eu(tpb-H)3(bipy)]weresynthesizedfrombi-dentaloxygenandnitrogenligands.LuminescentpolymerswerefabricatedbyincorporatingdeuteratedEu(Ⅲ)complexesinpoly(methylmethacrylate)(PMMA)matrixes.LuminescentPMMAcontainingEu(tpb-D)3(phen)exhibitedrelativelyhigherquantumyield[Φ,(48.7±4)%],fasterradiationrate(kr,7.49×102s-1),sharperredemission[fullwidthathalfmaximum(FWHM),6.3nm]andlargerstimulatedemissioncross-section(SEC,1.29×10-20cm2).ThevalueofSECisthesameorderasthatofNd-glasslaserforpracticaluse.Additionally,thethermalpropertiesofEu(tpb-H)3(phen),Eu(tpb-H)3(bipy),Eu(tpb-D)3(phen)-PMMA,andEu(tpb-H)3(bipy)PMMAwerestudied,indicatingthattheEu(Ⅲ)complexesandluminescentPMMAcanbeusedforalong-termperiodinhightemperatureenvironment.PreparedluminescentpolymersincludingEu(tpb-D)3(phen)havepromisingapplicationsinnovelorganicEu(Ⅲ)devices,suchasthehigh-powerlasermaterialsandopticalfibers.

简介：Theworkpresentedinthispaperisastudyofoutputtemporalcontrastdegradationbynear-fieldqualitydeterioration,suchasintensitymodulationandwavefrontdeviation,inalargeaperturehighpowershortpulselasersystem.AtwostepfocusingalgorithmwithacoordinatetransformbasedontheFresnelapproximationinthespacedomainisusedforsimulatingtheoutputfocusedbyanoff-axisparabolicmirror.Thetemporalcontrastdegradationbyintensitymodulationandwavefrontdeviationisanalyzedandtheinfluenceofthediameteronthetemporalcontrastdegradationisrevealed.ThesimulationandassumptionresultsbasedontheparametersoftheShenGuang-IIlasersystemarecomparedwiththeonlineexperimentaltemporalcontrastdata.Thenear-fieldqualitydeteriorationmightleadtotemporalcontrastdegradation,hinderinghighertemporalcontrastinlargeaperturehighpowershortpulselasersystems.

简介：Weexperimentallydemonstratehighopticalqualityfactorsilicamicrodiskresonatorsonasiliconchipwithlargewedgeanglesbyreactiveionetching.For2-μm-thickmicroresonators,wehaveachievedwedgeanglesof59°,63°,70°,and79°withopticalqualityfactorsof2.4×10~7,8.1×10~6,5.9×10~6,and7.4×10~6,respectively,from～80μmdiametermicroresonatorsinthe1550nmwavelengthband.Also,for1-μm-thickmicroresonators,wehaveobtainedanopticalqualityfactorof7.3×10~6withawedgeangleof74°.

简介：Inthispaper,analmostP-stabletwo-stepsixth-orderHybridmethodwithphase-lagoforderinfinityandaclassexpliciteighth-orderObreckoffmethodswithphase-lagoforder10-24aredevelopedforthenumericalintegrationofthespecialsecond-orderperiodicinitial-valueproblems.Thesemethodshavetheadvantageofhigheralgebraicorderandconsiderablysmallerphase-tagcomparedwithsomemethodsin[1-6].Numericalexamplesindicatethatthesenewmethodsaremoreaccuratethanmethodsdevelopedby[1-6].

简介：Highenergyprotonbeamhasthelongpenetrationlengthinsolidmatteranditcouldproducetheradiographsandindicatethetomographyandmaterialpropertiesinsideofthespecimen.Consideringtheexpensivecoststoconstructahighenergyprotonaccelerator,theothercandidateofhighenergyelectronbeambecomesmoreacceptable[1??3].Duetothehighspatialandtemperalresolutionofhighenergyelectronbeam.Itisapowertooltodiagnosetheinnerstructurechangeduringthehighenergydensitymatterproductionandtheinertialconfinementfusionprocess.Inordertostudythedensityresolutionofthehighenergyelectronbeamradiography,astep-targetwasdesignedandproduced.ThestructureandthetargetpicturesareshowninFig.1andtheSitargetswithdifferentslot-widthwereproducedbyusingthemicroetchtechnics.