简介:Anewmethodfordeterminingthepartialmeltingdepthofmantle-derivedmagmaandlithosphericthicknessincontinentalregionsisderivedfromREEgeochemistry.ThiseffectivetechniqueusesvariationsintheCe/YbandSm/YbratiosfoundinmainlyvolcanicrocksincontinentalChina.TheratioschangewiththedepthoforiginconsistentwiththecorrelationbetweenlithosphericthicknessandtheCe/YbandSm/Ybratiosfoundinoceanicbasalt.Theseratiosincreaseexponentiallywiththedepthoforigin,thelithosphericthickness,ofawidevarietyofCenozoicvolcanicbasaltandPaleozoickimberliteintheNorthChinaCraton,northeasternChinacontinentandvicinity.Thisfunctionalrelationshipwithdepthisshowninaplotoftheratiosthatformsaconcordiacurve,whichiscloselyexpressedbyformulasusing8-degreepolynomials.Theseprovideamoreaccurategageinmeasuringthelithosphericthicknessthanthetraditionalgeophysicalmethods.Whenappliedtovolcanicrockofdifferentagesitalsorevealshowthethicknesshaschangedovertimeandthus,greatlyaidstheunderstandingofthetectonichistory.RelationsbetweentheCO2content,mineralreactionsandpressureintheupperasthenospherebeneaththebaseofthelithosphereappearstoaffecttheproportionsofREEinpartialmeltsandbringsaboutaclosecorrelationbetweenlithosphericthicknessandtheCe/YbandSm/Ybratiosinmantle-derivedmagmaticrock.Thisthicknessgauge,forbothcontinentalandoceaniclithosphere,providesanewapproachinanalyzingthelithosphericthicknessindifferenttectonicsettingsandgeologictimes.
简介:Inthispaper,Er/Ybco-dopedfiberamplifiers(EYDFAs)withanYb-bandfiberBragggrating(FBG)atthepumpendtoimprovetheperformanceoftheamplifierissystematicallystudied.TheinfluenceofthereflectivityandcenterwavelengthoftheFBGalongwiththegain-fiberlengthontheperformanceofanEYDFAarenumericallyanalyzed.TheresultsshowthatthewavelengthoftheFBGhascriticalinfluenceontheefficiencyoftheEYDFA,whereastherequirementtoitsreflectivityisrelaxed.Itisaneffectiveandpromisingwaytoimprovetheefficiencyofahigh-powerpumpedEYDFAbyintroducingasuitableYb-bandFBGatthepumpend.Basedontheanalysisoftheunderlyingprinciples,suggestionsforthepracticaldesignandpossiblefurtherimprovementstrategiesarealsoproposed.
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简介:(EC+β+)Decayof153Erand157Yb¥XuShuwei;XieYuanxiang;PanQiangyan;ZhangJuping;ZhangXueqian;WangYihao;GeYuanxiu;YinXijin?..
简介:TheperformancesofhighpowerEr/Ybcodopedfiberlinearcavitylasersareinvestigatednumerically.ThenumericalanalysisisbasedontheiterativesolutionofrateequationsforpopulationdensityoftheEr/Ybions.Thebehaviorsofco-pumpandcounter-pumpmethodsarecontrasted.Dependenceofoutputpoweroninputpumppower,outputreflectivity,operatingwavelengthandactivefiberlengthissimulated,respectively.HighconversionefficiencyEr/Yblaseroutputisobtainedinsimulationsandexperiments.
简介:AmicrocalorimetricmethodwasusedtoevaluatetheactionofYb^3+ionsonthegrowthmetabolismofStaphylococcusaureus.Thepower-timecurvesofthegrowthmetabolismofStaphylo.coccusaureusandtheactionofYb^3+ionswereobtainedbyus-ingstopped-flowmethodat37℃.Forevaluationoftheaction,thegrowthrateconstants(k1andk2)forthelogphase1,logphase2,andthetotalheateffect(Qtotal)forStaphylococcusaureusweredetermined.TheresultsshowthatYb^3+ionsatlowconcentrationshavethestimnlatoryeffectonStaphylococcusau-reusandthatYb^3+ionsathigherconcentrationcouldinhibititsgrowth.
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简介:TheNaYF4:Yb,Ernanocrystalsweresynthesizedviathethermaldecompositionofmetaloleateprecursors.Thenanocrystalsinhexagonalstructurewerehighlyuniformandinsizeof25nm.Thebrightupconversionluminescencewasobservedundertheexcitationof980nmlaserandtheupconversionemissionspectrawereinvestigatedatdifferentpumppowers.Theemissionintensityratioofredlighttogreenlightlinearlyincreasedwithpumppowerincreasing.ThisresultindicatedthatthereexistedalargethresholdpowerofsaturationpumpforthefirstexcitationstateinNaYF4:Yb,Ernanocrystalscomparingtothatinbulkmaterial.
简介:摘要地层精细划分对比是油田地质的基础,通过地层精细划分对比,可以解决油田开发过程中的许多地质问题,为了解决YB油区含水率较高、自然递减率较快、后期注水等问题,充分利用各阶段的分析资料,对目的层进行地层划分对比,为下一步油田开发方案调整和综合治理奠定必要的基础。
简介:[摘要]小盒透明纸包装机整形装置是通过凸轮摆杆带动上下两组加热器进行开合运动,对完成透明纸折叠和热封的烟包上下两个面进行美容热封。较长时间停机时通过气缸控制加热器脱开,避免烫坏烟包。在实际生产中气缸支撑轴时有发生断裂现象,造成烟包粘连、烟包表面烫坏等质量问题,为了提高支撑轴的使用寿命,通过改进设计,将气缸由单点悬臂梁支撑改为双点支撑,改进后支撑轴的断裂次数明显降低,减少了烟包质量问题,提高了设备的有效作业率,具有较高的应用价值。
简介:Yb3+complexeswithtwonitrilotriaceticacidmoleculeswerepreparedandtheircompositionsweredeterminedasK3[Yb(nta)2(H2O)]*5H2OandNa3[Yb(nta)2]*6H2Obyelementalanalyses.Theirstructureswerecharacterizedbysingle-crystalX-raydiffractionanalyses.IncomplexK3[Yb(nta)2(H2O)]*5H2O,theYbN2O7partformsanine-coordinatemonocappedsquareantiprismaticstructure.IncomplexNa3[Yb(nta)2]*6H2O,theYbN2O6partformsaneight-coordinatesquareantiprismaticstructure.Itcanbeseenthattheoutercations(K+andNa+)greatlyaffectthecoordinationnumberandcoordinatestructurefromtheseresults.
简介:Thehighrepetitionrate10J/10nsYb:YAGlasersystemanditskeytechniquesarereported.Theamplifiersinthissystemhaveamulti-passV-shapestructureandtheheatintheamplifiersisremovedbymeansoflaminarwaterflow.Inthemainamplifier,thelaserisfour-pass,andanapproximately8.5J/1Hz/10nsoutputisachievedintheprimarytest.Thefar-fieldoftheoutputbeamisapproximately10timesthediffractionlimit.Becauseofthehigherlevelsofamplifiedspontaneousemission(ASE)inthemainamplifier,theoutputenergyislowerthanexpected.Attheendwediscusssomemeasuresthatcanimprovethepropertiesofthelasersystem.
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简介:AcompositetransparentYAG/Yb:YAG/YAGceramicwaspreparedbyanon-aqueoustape-castingmethod.Anopticaltransmittanceof82%wasobtainedatvisiblewavelengthandaround1100nm.Alow-threshold,broadbandtunablecontinuous-wave(CW)laserat1031nmwasfurtherdemonstratedfromtheceramicsample,whichwaspumpedbya974nmfiber-pigtailedlaserdiode.Thethresholdpumppowerwas0.45Wandthemaximumoutputpowerwas3.2W,correspondingtoaslopeefficiencyof20.4%.ByinsertinganSF57prisminthelasercavity,theoutputwavelengthcouldbetunedcontinuouslyfrom1021to1058nm.