简介：TheChineseFusionEngineeringTokamakReactor(CFETR)isanimportantintermediatedevicebetweenITERandDEMO.TheWaterCooledCeramicBreeder(WCCB)blanketwhosestructuralmaterialismainlymadeofReducedActivationFerritic/Martensitic(RAFM)steel,isoneofthecandidateconceptualblanketdesign.AnanalysisofrippleanderrorfieldinducedbyRAFMsteelinWCCBisevaluatedwiththemethodofstaticmagneticanalysisintheANSYScode.Significantadditionalmagneticfieldisproducedbyblanketanditleadstoanincreasedripplefield.Maximumripplealongtheseparatrixlinereaches0.53%whichishigherthan0.5%oftheacceptabledesignvalue.Simultaneously,oneblanketmoduleistakenoutforheatingpurposeandtheresultingerrorfieldiscalculatedtobeseriouslyagainsttherequirement.

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简介：OpticalemissionfromTiO_2plasma,generatedbyananosecondlaserisspectroscop-icallyanalysed.Themainchemicalspeciesareidentifiedandthespatio-temporaldistributionoftheplasmaparameterssuchaselectrontemperatureanddensityarecharacterizedbasedonthestudyofspectraldistributionofthelineintensitiesandtheirbroadeningcharacteristics.Thepa-rametersoflaserinducedplasmavaryquicklyowingtoitsexpansionatlowbackgroundpressureandthepossibledeviationsfromlocalthermodynamicequilibriumconditionsaretestedtoshowitsvalidity.

简介：The45°scatteringofafemtosecond(60fs)intenselaserpulsewitha20nmFWHM(thefullwidthathalfmaximum)spectrumcenteredat790nmhasbeenstudiedexperimentallywhilefocusedinargonclustersatintensity～1016W/cra2.Scatteringspectraunderdifferentbackingpressuresandlaser-plasmainteractionlengthswereobtained,whichshowedspectralblueshifting,beamrefractionandcomplexmodulation.Theseionization-inducedeffectsrevealthemodulationoflaserpulsespropagatinginplasmasandtheexistingobstacleinlaserclusterinteractionathighlaserintensityandhighelectrondensity.

简介：Inthiswork,laserinducedtungstenplasmahasbeeninvestigatedintheabsenceandpresenceof0.6Tstatictransversemagneticfieldatatmosphericpressureinair.Thespectroscopiccharacterizationoflaserinducedtungstenplasmawasexperimentallystudiedusingspace-resolvedemissionspectroscopy.Theatomicemissionlinesoftungstenshowedasignificantenhancementinthepresenceofamagneticfield,whiletheionicemissionlinesoftungstenpresentedlittlechange.Temporalvariationoftheopticalemissionlinesoftungstenindicatedthattheatomicemissiontimeinthepresenceofamagneticfieldwaslongerthanthatintheabsenceofamagneticfield,whilenosignificantchangesoccurredfortheionicemissiontime.Thespatialresolutionofopticalemissionlinesoftungstendemonstratedthatthespatialdistributionofatomsandionswereseparated.Theinfluenceofamagneticfieldonthespatialdistributionofatomswasremarkable,whereasthespatialdistributionofionswaslittleinfluencedbythemagneticfield.Thedifferentbehaviorsbetweenionsandatomswithandwithoutmagneticfieldinairwererelatedtothevariousatomicprocessesespeciallytheelectronsandionsrecombinationprocessduringtheplasmaexpansionandcoolingprocess.

简介：Thepoloidalrotationofthemagnetizededgeplasmaintokamakdrivenbytheponderomotiveforcewhichisgeneratedbyinjectinglowerhybridwave(LHW)electricfieldhasbeenstudied.TheLHWislaunchedfromawaveguideintheplasmaedge,andbyBrambilla’sgrilltheory,analyticexpressionsforthewaveelectricfieldintheslabmodelofaninhomogeneouscoldplasmahavebeenderived.ItisshownthatastrongwaveelectricfieldwillbegeneratedintheplasmaedgebyinjectingLHwaveofthepowerinMWmagnitude,andthiselectricfieldwillinduceapoloidalrotationwithashearedpoloidalvelocity.PACS:52.55.Fa

简介：Thezonalfieldseffectonthebeta-inducedAlfveneigenmode(BAE)destabilizedbytheenergeticparticlesintoroidalplasmasisstudiedthroughthegyrokineticparticlesimulations.ItisfoundthatthelocalizedzonalfieldswithanegativevaluearoundthemoderationalsurfacearegeneratedbythenonlinearBAE.Intheweaklydrivencase,thezonalfieldswithastronggeodesicacousticmode(GAM)componenthaveweakeffectsonthenonlinearBAEevolution.Inthestronglydrivencase,thezonalfieldsaredominatedbyamoresignificantzerofrequencycomponentandhavestrongereffectsonthenonlinearBAEevolution.

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简介：Laser-inducedbreakdownspectroscopy(LIBS)wasexaminedtodetectatracesubstanceadheredontoAlalloysforthesurfaceinspectionofmaterialstobeadhesivelybonded.AsanexampleofSicontamination,siliconeoilwasemployedandsprayedontosubstrateswithacontrolledsurfaceconcentration.LIBSmeasurementsemployingnanosecondUVpulses(λ=266nm)andanoff-axisemissioncollectionsystemwithdifferentdetectingheightswereperformed.Becausesurfacecontaminantsareinvolvedintheplasmaformedbylaserablationofthesubstrates,therelativecontributionofthesurfacecontaminantsandthesubstratestotheplasmaemissioncouldbechangeddependingontheconditionsforplasmaformation.Thelimitofdetection(LOD)wasevaluatedunderseveraldetectingconditionsforinvestigatingthefactorsthataffectedtheLOD.Asignificantfactorwasthestandarddeviationvaluesofsignalintensitiesobtainedforthecleansubstrates.Thisvaluevarieddependingonthemeasurementconditions.FortheAlalloy(A6061),thesmallestLODobtainedwas0.529μg·cm^-2.Furthermore,animprovedLOD(0.299μg·cm^-2)wasobtainedfortheAlalloywithalowerSicontent.

简介：Laser-inducedbreakdownspectroscopy(LIBS)wasdevelopedtodetectaluminuminnickel-basedsuperalloys(K417,GH4033,DZ125L,(?)742y)usinganon-intensified,non-gated,low-costdetectionsystem.TheprecisionofLIBSdependsstronglyontheexperimentalconditions.ThecalibrationcurvesofA1(I)394.4nmandA1(I)396.2nmundertheoptimumexperimentalparametersarepresented.Finallythelimitofdetection(LOD)foraluminumiscalculatedfromtheexperimentaldata,whichisintherangeof0.09%to0.1%byweight.

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简介：Accordingtothemultipleresearchesinthelastcoupleofyears,laser-inducedbreakdownspectroscopy(LIBS)hasshownagreatpotentialforrapidanalysisinsteelindustry.Nevertheless,theaccuracyandprecisionmaybelimitedbycomplexmatrixeffectandself-absorptioneffectofLIBSseriously.Anovelmultivariatecalibrationmethodbasedongeneticalgorithm-kernelextremelearningmachine(GA-KELM)isproposedforquantitativeanalysisofmultipleelements(Si,Mn,Cr,Ni,V,Ti,Cu,Mo)inforty-sevencertifiedsteelandironsamples.First,thestandardizedpeakintensitiesofselectedspectralinesareusedastheinputofmodel.Then,thegeneticalgorithmisadoptedtooptimizethemodelparametersduetoitsobviouscapabilityinfindingtheglobaloptimumsolution.Basedonthesetwostepsabove,thekernelmethodisintroducedtocreatekernelmatrixwhichisusedtoreplacethehiddenlayer’soutputmatrix.Finally,theleastsquareisappliedtocalculatethemodel’soutputweight.InordertoverifythepredictivecapabilityoftheGA-KELMmodel,theR-squarefactor(R2),Root-mean-squareErrorsofCalibration(RMSEC),Root-mean-squareErrorsofPrediction(RMSEP)ofGA-KELMmodelarecomparedwiththetraditionalPLSalgorithm,respectively.TheresultsconfirmthatGA-KELMcanreducetheinterferencefrommatrixeffectandself-absorptioneffectandissuitableformulti-elementscalibrationofLIBS.

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简介：Laser-inducedbreakdownspectroscopy(LIBS)hasattractedextensiveattentionasanewtechniqueforin-situmarineapplication.Inthiswork,theinfluenceofdeep-seahighpressureenvironmentonLIBSsignalswasinvestigatedbyusingacompactLIBS-seasystemdevelopedbyOceanUniversityofChinaforthein-situchemicalanalysisofseawater.TheresultsfromthefieldmeasurementsshowthattheliquidpressurehasasignificanteffectontheLIBSsignals.Higherpeakintensityandlargerlinebroadeningwereobtainedasthepressureincreases.BycomparingthevariationsofthetemperatureandsalinitywiththeLIBSsignals,aweakcorrelationbetweenthemcanbeobserved.Underhighpressureconditions,theoptimallaserenergywashigherthanthatinairenvironment.Whenthelaserenergyexceeded17mJ,theeffectoflaserenergyonthesignalintensityweakened.Thesignalintensitydecreasesgraduallyatlargerdelays.TheobtainedresultsverifiedthefeasibilityoftheLIBStechniqueforthedeep-seain-situdetection,andwehopethistechnologycancontributetosurveyingmoredeep-seaenvironmentssuchasthehydrothermalventregions.

简介：Asanimportantnon-ferrousmetalstructuralmaterialmostusedinindustryandproduction,aluminum(Al)alloyshowsitsgreatvalueinthenationaleconomyandindustrialmanufacturing.HowtoclassifyAlalloyrapidlyandaccuratelyisasignificant,popularandmeaningfultask.Classificationmethodsbasedonlaser-inducedbreakdownspectroscopy(LIBS)havebeenreportedinrecentyears.AlthoughLIBSisanadvanceddetectiontechnology,itisnecessarytocombineitwithsomealgorithmtoreachthegoalofrapidandaccurateclassification.Asanimportantmachinelearningmethod,therandomforest(RF)algorithmplaysagreatroleinpatternrecognitionandmaterialclassification.ThispaperintroducesarapidclassificationmethodofAlalloybasedonLIBSandtheRFalgorithm.TheresultsshowthatthebestaccuracythatcanbereachedusingthismethodtoclassifyAlalloysamplesis98.59%,theaverageofwhichis98.45%.ItalsorevealsthroughtherelationshiplawsthattheaccuracyvarieswiththenumberoftreesintheRFandthesizeofthetrainingsamplesetintheRF.Accordingtothelaws,researcherscanfindouttheoptimizedparametersintheRFalgorithminordertoachieve,asexpected,agoodresult.TheseresultsprovethatLIBSwiththeRFalgorithmcanexactlyclassifyAlalloyeffectively,preciselyandrapidlywithhighaccuracy,whichobviouslyhassignificantpracticalvalue.

简介：MutantstrainsofGOl12andBM302withahigh2-keto-L-gulonicacid(2KLG)transformationrateinducedbyionbeamimplantationwereseparatelyandcombinatoriallycom-paredwiththeoriginalstrainsGO29andBM80tostudythemutageniceffectsofionbeamimplan-tation.BoththesoleGO112andmixedBM302:GO112demonstratedimprovedSNDHactivityand2KLGyieldcomparedtotheoriginalstrains.ThemutantcombinationsofBM302:GO112showedalongerstationaryphaseandhigherbiomassthanBM80:GO29.ThemutantBM302exhibitedastrongercapacitytomaintainastablepHenvironmentatmixedfermentationwithGluconobacteroxydans(G.oxydans)for2KLGtransformationandfacilitatedthegrowthofG.oxydanscomparedwiththeoriginalstrainBM80.ThepromotivecapacitytoL-sorbosonedehy-drogenase(L-SNDH)fromthesupernateofBM302was1.6-foldhigherthanthatofBM80.GenesencodedSNDHinGO29andGOl12wereamplifiedandsequenced,andmutationsincludingthreetransitions(CG→TA,CG→TA,GC→AT)andonetransversion(AT→TA)wereconfirmedfromGO29toGO112.ThecorrespondingaminoacidwaschangedasLeu→Phe,Arg→GlnandAsn→Lys.

简介：Oneofthetechnicalbottlenecksoftraditionallaser-inducedbreakdownspectroscopy(LIBS)isthedifficultyinquantitativedetectioncausedbythematrixeffect.Totroubleshootthisproblem,thispaperinvestigatedacombinationoftime-resolvedLIBSandconvolutionalneuralnetworks(CNNs)toimproveKdeterminationinsoil.Thetime-resolvedLIBScontainedtheinformationofbothwavelengthandtimedimension.Thespectraofwavelengthdimensionshowedthecharacteristicemissionlinesofelements,andthoseoftimedimensionpresentedtheplasmadecaytrend.Theone-dimensionaldataofLIBSintensityfromtheemissionlineat766.49nmwereextractedandcorrelatedwiththeKconcentration,showingapoorcorrelationofR^2c=0.0967,whichiscausedbythematrixeffectofheterogeneoussoil.Forthewavelengthdimension,thetwo-dimensionaldataoftraditionalintegratedLIBSwereextractedandanalyzedbyanartificialneuralnetwork(ANN),showingR^2v=0.6318andtherootmeansquareerrorofvalidation(RMSEV)=0.6234.Forthetimedimension,thetwo-dimensionaldataoftime-decayLIBSwereextractedandanalyzedbyANN,showingR^2v=0.7366andRMSEV=0.7855.Thesehigherdeterminationcoefficientsrevealthatboththenon-KemissionlinesofwavelengthdimensionandthespectraldecayoftimedimensioncouldassistinquantitativedetectionofK.However,duetolimitedcalibrationsamples,thetwo-dimensionalmodelspresentedover-fitting.Thethree-dimensionaldataoftime-resolvedLIBSwereanalyzedbyCNNs,whichextractedandintegratedtheinformationofboththewavelengthandtimedimension,showingtheR^2v=0.9968andRMSEV=0.0785.CNNanalysisoftime-resolvedLIBSiscapableofimprovingthedeterminationofKinsoil.

简介：Thecomplexnatureoflaser-materialinteractioncausesnon-stoichiometricablationofalloysamples.Thisisattributedtomatrixeffect,whichreducesanalyzingcapability.Toaddressthisissue,theanalyticalperformanceofthreedifferentnormalizationmethods,namelynormalizationwithbackground,internalnormalizationandthreepointsmoothingtechniquesatdifferentparametersettingsisstudiedforquantificationofAgandZnbyLaserinducedbreakdownspectroscopy(LIBS).TheLIBSspectraoffiveknownconcentrationofsilverzincbinarycompositeshavebeeninvestigatedatvariouslaserirradiances(LIs).CalibrationcurvesforbothAg(I)line(4d^105s^2S1/2→4d^105p^2P1/2at338.28nm)andZn(I)line(4s5s^3S1→4s4p^3P2at481.053nm)havebeendeterminedatLIof5.86×10^10Wcm^-2.SlopesofthesecalibrationcurvesprovidethevaluationofmatrixeffectintheAg–Zncomposites.Withcarefulsamplepreparationandnormalizationaftersmoothingatoptimumparametersetting(OPS),theminimizationofsamplematrixeffecthasbeensuccessfullyachieved.AgoodlinearityhasbeenobtainedinAgandZncalibrationcurveatOPSwhennormalizedthewholeareaofspectrumaftersmoothingandtheobtainedcoefficientsofdeterminationvalueswereR^2=0.995and0.998closerto1.Theresultsofmatrixeffecthavebeenfurtherverifiedbyanalysisofplasmaparameters.BothplasmaparametersshowednochangewithvaryingconcentrationatOPS.However,athighconcentrationofAg,theobservedsignificantchangesinbothplasmaparametersatcommonparametersettingPS-1andPS-2werethegestureofmatrixeffect.Inourcase,thebetteranalyticalresultswereobtainedatsmoothingfunctionwithoptimizedparametersettingthatindicatesitismoreefficientthannormalizationwithbackgroundandinternalnormalizationmethod.

简介：Indouble-pulselaser-inducedbreakdownspectroscopy(DP-LIBS),thecollinearfemtoseconddouble-pulselaserconfigurationisexperimentallyinvestigatedwithdifferentinitialsampletemperaturesusingaTi:sapphirelaser.Theglasssampleisablatedtoproducetheplasmaspectroscopy.Duringtheexperiment,thedetectedspectrallinesincludetwoNa(I)lines(589.0nmand589.6nm)andoneCa(I)lineatthewavelengthof585.7nm.Theemissionlinesaremeasuredatroomtemperature(22°C)andthreehigherinitialsampletemperatures(Ts=100°C,200°C,and250°C).Theinter-pulsedelaytimerangesfrom-250psto250ps.Theinter-pulsedelaytimeandthesampletemperaturestronglyinfluencethespectralintensity,andthespectralintensitycanbesignificantlyenhancedbyincreasingthesampletemperatureandselectingtheoptimizedinter-pulsetime.Forthesameinter-pulsetimeof0ps(single-pulseLIBS),theenhancementratioisapproximately2.5atTs=200°CcomparedwiththatobtainedatTs=22°C.Forthesameinter-pulsetimeof150ps,theenhancementratiocanbeupto4atTs=200°CcomparedwiththatobtainedatTs=22°C.Thecombinedenhancementeffectsofthedifferentinitialsampletemperaturesandthedouble-pulseconfigurationinfemtosecondLIBSaremuchstrongerthanthatofthedifferentinitialsampletemperaturesorthedouble-pulseconfigurationonly.

简介：Anexperimentalsetuphasbeendesignedandrealizedinordertooptimizethecharacteristicsoflaser-inducedbreakdownspectroscopysystemworkinginvariouspressureenvironments.Anapproachcombinedthenormalizationmethodswiththepartialleastsquares(PLS)methodaredevelopedforquantitativeanalysisofmolybdenum(Mo)elementinthemulti-componentalloy,whichisthefirstwallmaterialintheExperimentalAdvancedSuperconductingTokamak.Inthisstudy,thedifferentspectralnormalizationmethods(totalspectralareanormalization,backgroundnormalization,andreferencelinenormalization)areinvestigatedforreducingtheuncertaintyandimprovingtheaccuracyofspectralmeasurement.TheresultsindicatesthattheapproachofPLSbasedoninter-elementinterferenceissignificantlybetterthantheconventionalPLSmethodsaswellastheunivariatelinearmethodsinthevariouspressureformolybdenumelementanalysis.