简介：YB2系列隔爆型三相异步电动机是南阳防爆电气研究所于1994年组织防爆电机行业联合设计开发的第一代隔爆型三相异步电动机。是YB系列电机的更新换代产品。1997年,南阳防爆电气研究所根据YB2系列电机样机试制情况,组织YB2系列电机联合设计工作组对其进行修改定型,并在防爆电机行业推广至今。目前,YB2系列隔爆型三相异步电动机已全面代替YB系列隔爆型三相异步电动机,成为行业的主导产品。近年来,国家有关部门发布了推行机电产品用硅钢片“以冷代热”的产品政策,制定了强制性国家标准,以法律的形式对电动机的能效指标加以限定,并发布和修订了相关的部分国家标准、行业标准。YB2系列隔爆
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：Wepresentanultrabroadband,high-speedwavelength-sweptsourcebasedonaself-modulatedfemtosecondoscillator.Photoniccrystalfiberwaspumpedbyamode-lockedYb:CaF2laser,resultinginastrongspectralbroadeningfrom485to1800nm.Thepumplasercavitycouldberealignedinordertoachievetotalmode-lockingofthelongitudinalandtransverseTEM00andTEM01electromagneticmodes.Thisledtospatialoscillationsoftheoutputbeam,whichinducedmodulationofthecouplingefficiencytothefiber.Duetothefactthatnonlinearspectralbroadeningwasintensitydependent,thismechanismintroducedwavelengthsweepingatthefiberoutput.Thesweepingratecouldbeadjustedbetween7and21.5MHzbychangingthegeometryofthepumpcavity.Bycontrollingtheratioofthetransversemodeamplitudes,wewereabletotunethesweepingbandwidth,eventuallycoveringboththe1300nmand1700nmbioimagingtransparencywindows.Whencomparedwithpreviouslydemonstratedwavelength-sweptsources,ourconceptoffersmuchbroadertunabilityandhigherspeed.Moreover,itdoesnotrequireanadditionalintensitymodulator.
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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![Syntheses and Structural Researches of <b style='color:red'>Yb</b>^3＋ Complexes with Nitrilotriacetic Acids—Nine—coordinate K3[<b style='color:red'>Yb</b>（nta）<b style='color:red'>2</b>（H<b style='color:red'>2</b>O）]·5H<b style='color:red'>2</b>O and Eight—coordinate Na3[<b style='color:red'>Yb</b>（nta）<b style='color:red'>2</b>]·6H<b style='color:red'>2</b>O complexes](/image/thesis6 "Syntheses and Structural Researches of <b style='color:red'>Yb</b>^3＋ Complexes with Nitrilotriacetic Acids—Nine—coordinate K3[<b style='color:red'>Yb</b>（nta）<b style='color:red'>2</b>（H<b style='color:red'>2</b>O）]·5H<b style='color:red'>2</b>O and Eight—coordinate Na3[<b style='color:red'>Yb</b>（nta）<b style='color:red'>2</b>]·6H<b style='color:red'>2</b>O complexes")
