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178 个结果
  • 简介:ThereactionofNdCl3withlithiummethylnaphthalenein1:2moleratioinTHFgeneratesblackpowder.Thepowderreactswithcyclooctatetraene(COT)inTHFtoformthetitlecomplex.[Li(THF)4Nd(C8H8)22THFcrystallizesinthemonoclinicspacegroupP2/cwithunit-celldimensionsa=1.7858(7)nm,h=1.3243(4)nm,c=1.8086(6)nm.β=106.52(4)°,V=4.10nm3andDc=1.268g/cm3forZ=4.F(000)=1660,R=0.0774,Rn=0.0733.Thecomplexconsistsofdiscreteion-pairandtwoTHFmoleculesadduct.Intheanion,theneodymiumatomiscoordinatedbytwoCOTrings.ThestructureofthecationshowsthatthelithiumatomisattachedwithTHFmoleculesonly.

  • 标签: CRYSTAL STRUCTURE ND Cyclooctatetraene
  • 简介:Thesinglecrystalofthecomplex[Sc(NO3)3(H2O)2]·(15C5)hasbeenpreparedinacetonitrile.Thenewcomplexhasbeencharacterizedbyelementalanalysis,IRspectra,solubilityandmolarconductancemeasurements.ThestructureofthecomplexisdeterminedbysinglecrystalX-raydiffractionanalysis.

  • 标签: solubility acetonitrile Crown molar H2O NO3
  • 简介:Aseriesofnovelbluelong-lastingphosphorescencephosphorsSr6Al18Si2O37:Eu2+,RE3+(RE3+=Ho3+,Gd3+,Dy3+andPr3+)werepreparedbytheconventionalhigh-temperaturesolid-statereactioninareductiveatmosphere.TheirpropertiesweresystematicallyinvestigatedutilizingX-raydiffraction(XRD),photoluminescence,phosphorescenceandthermoluminescence(TL)spectra.ThephosphorsemittedbluelightthatwasrelatedtotheemissionofEu2+dueto5d-4ftransition.Brightbluelong-lastingphosphorescence(LLP)couldbeobservedaftertheexcitationsourcewasswitchedoff.Fortheoptimizedsample,thebluelong-lastingphosphorescencecouldlastfornearly4hinthelightperceptionofthedark-adaptedhumaneye(0.32mcd/m2).TheeffectsofRE3+ionsonphosphorescencepropertiesofthephosphorswerestudied,andtheresultsshowedthattheco-dopingofRE3+ionsgreatlyenhancedtheintensityofthepeakaround315Kwhichwasrelatedtothelonglastingphosphorescenceofthephosphorsatroomtemperatureandconsequentlyimprovedtheperformanceofthebluephosphorescencesuchasintensityandpersistenttime.

  • 标签: 荧光粉 长余辉 磷光 蓝色 发光特性 高温固相反应
  • 简介:介绍了江西铜业集团公司贵溪冶炼厂动力1^#、2^#抛煤机锅炉除尘器运行的状况,对影响文丘里水膜除尘效率的各种因素进行了详细分析,并介绍了提高文丘里水膜除尘效率的一些措施及取得的效果。

  • 标签: 锅炉 除尘器 效率 因素分析 效果分析
  • 简介:分析了山西分公司二期CO2压缩机润滑油消耗高的原因,介绍了采取的针对措施以及2002年取得的节能效果,并进一步指出了CO2压缩机的节能空间.

  • 标签: CO2压缩机 润滑油 节能 节油措施 氧化铝
  • 简介:本文分析了某公司二期CO2压缩机润滑油消耗高的原因。提出了改进措施。以及实施后取得了较好的节能效果,进一步指出了CO2压缩机的节能空间。

  • 标签: CO2压缩机 润滑油 消耗
  • 简介:EffectofLa-richrareearthoneutecticmicrostructureinA1-2%Fealloywasstudied.WhentheadditionofREissmall,a-A1phaseisintheformofcellulardendrite.WiththeincreaseoftheadditionofRE,thenucleationandgrowthofa-A1dendritearesuppressed,andeutecticAl3Fephaseisrefined.WhentheadditionofREgetsto0.6%(massfrac-tion),thesizeofeutecticAl3Feincreases.Inaddi-tion,mechanismoftheeffectofmixedREoneutecticmorphologyofA1-2%Fealloyisexplored.

  • 标签: 共熔铝铁合金 稀土元素 微观结构 精炼方法 金属材料
  • 简介:Differentfluxeswereusedtosynthesizelongpersistencephosphors,calciumsulfidesactivatedbyEu2+andTm3+,byconvenientsolid-statemethod.ThephosphorusingNH4Fasafluxhasgoodcrystallinityandlargeparticlesize,itsstabilityagainstwaterandotheratmosphericcomponentsisenhanced,anditsafterglowislongerandfluorescentintensityismoreintensethanthoseofthephosphorusingNH4Clasflux.TheirPLintensitiesvariedwithtimeinmoistairweremeasured,noremarkablechangewasfoundforthosepreparedwithNH4FfluxincontrastwithNH4Clasflux.SousingNH4Fasfluxisagoodmethodtoenhancethestabilityofalkalineearthsulfides.

  • 标签: 磷光体 CaS:Eu^2+/Tm^3+ 化学稳定性 稀土 硫化钙 铕二价
  • 简介:本文分析了山西分公司二期CO2压缩机润滑油消耗高的原因,介绍了采取的针对措施以及2002年取得的节能效果,并进一步指出了CO2压缩机的节能空间.

  • 标签: CO2压缩机 润滑油 消耗
  • 简介:日本产业技术综合研究所的科学家发现,通过在负极中采用微细管结构的材料,可将锂离子充电电池的功率密度提高数十倍。负极采用的材料是“结晶性金属氧化物复合纳米多孔材料”。其结构由直径SNMP左右的微细管规则地排列而成,通过这种微细管,不仅锂离子与电解液能够容易地流向电极内部,而且还具有增大锂离子吸附的表面面积的作用。由此,在维持与现有锂离子充电电池相同的能量密度的同时,还可提高功率密度。

  • 标签: 纳米多孔材料 锂离子电池 高功率密度 负极材料 日本科学家 日本产业技术综合研究所
  • 简介:EffectofMnsubstitutionforFeincubicLavesZr0.1Tb0.9(Fe1-xMnx)2andY0.1Tb0.9(Fe1-xMnx)2com-poundsispresented.Similarresultsinbothsystemsareobtained:ThestructureandthemagnetismofTbFe2arebothinfluencedslightlybyasmallamountofYorZrsubstitutionforTb;Withincreasingxvalue,thelatticeconstantincreasesmonotonously;theCurietemperaturedecreaseslinearly;whilesaturationmagnetizationincreaseslinearly.ForthesmallamountofMnsubstitutionforFeinbothsystems,magnetostrictionissignificantlylargerthanthatinthepureironalloys.Thelargestmagnetostrictionof|γ‖-|γ|=2200×10-6atmagneticfieldof2×107/4πA/misobtainedforY0.1Tb0.9(Fe0.95Mn0.052.

  • 标签: MN MAGNETOSTRICTION Magnetic properties Cubic Laves
  • 简介:Awhitelong-lastingphosphorCa2MgSi2O7:Dy3+waspreparedbythesolid-statereaction.Astrongbandpeakedat260nmwasshownintheexcitationspectrumof578nmemission,whichmightbeattributedtotheoxygendeficiencyofthehost.Afterirradiatedwith254nmfor4min,thewhiteafterglowofthesamplecouldbeseenfor3h.Moreover,thedepthsandfrequencyfactorsoftrapcenterswerecal-culatedfromthethermo-luminescencecurveofthesample,whichindicatedthatthetrapcenterscorrespondingtothe414Kbandweremorehelpfultothelong-lastingphosphorescence.

  • 标签: WHITE long-lasting phosphor SILICATE DYSPROSIUM THERMO-LUMINESCENCE
  • 简介:美国宇航局在加州帕萨迪纳的喷气推进实验室研究成功了一种制造YBa2Cu3O7-α高温超导电缆(封装在金属套管内)的新方法。据称,这种方法成本较低,过程易于控制,且对各种前体材料有很强的适应能力。该法分4个步骤:生产具有化学(配)比的前体(Precursor)粉;将前体粉包封在金属套管内;用轧制的方法使前体粉固结;在液态锂金属浴槽内进行处理,使之转变成超导组

  • 标签: 粉末冶金 金属套管 高温超导电缆 锂金属 实验室研究 喷气推进
  • 简介:TheTiO2nanomembranedopedbyREionswerepreparedbymixingREionsintoTiO2solutionandthephoto-catalyticpropertiesofthecoatingglasswithTiO2membranedopedbyREionstomethylbenzenedegradationunderultravioletwereinvestigated.AFMphotoesshowthatthesurfaceofcoatingglasswithTiO2nanomembranedopedbyCe3+,Ce4+,Y3+arecomposedofparticleswithdiametersof30~50nm.Theresearchesonphoto-catalyticpropertiesprovethatthesurfaceofcoatingglasswithTiO2nanomembranedopedbyREionspossessesgoodphotocatalyticpropertiesunderultravioletandthedegradationpercentsofmethylbenzenearemorethan90%whenthedegradationtimeisshorterthan160min.WhenthemoleratioofCe3+,Y3+,Ce4+toTiO2is0.002thedegradationpercentsofmethylbenzenearerespectively92.85%,91.87%and91.15%under254~365nmultravioletin50μg·ml-1methylbenzenesolution.ThephotocatalyticabilityofthesurfaceofcoatingglasswithTiO2nanomembranedopedbyCe3+underultraviolettodegrademethylbenzeneincreasesastheconcentrationsofREionsincreaseandtheiroptimumpercentageofdegradationare98.50%,97.50%and96.35.5%respectively.Thehighertheconcentrationofmethylbenzenesolutionthelowerthepercentsofthemethylbenzenedegradationofthecoatingglassare,andthebiggertheratiooftheareasofcoatingglasstothevolumeofmethylbenzenesolutionthehigherthedegradationeffectofmethylbenzeneis.

  • 标签: TIO2 nanomembrane DOPED RE IONS COATING
  • 简介:Ceriasphereswithdifferentsizesandsulfurizedproductswithcorrespondingmorphologywerepreparedbyhydrothermalandgas-solidreactionmethodat600–800°CunderCS2atmosphereforashorttime,respectively.Dimensionaleffectinpreparationofγ-Ce2S3wasfirstlyinvestigatedbymeansoftechniquessuchasscanningelectronmicroscopy(SEM),X-raydiffraction(XRD),thermalgravimetricanalysis(TGA)andspectrophotometer.Theresultsshowedthatwhenceriananoparticleswithsmallsizewereusedasprecursors,theγ-Ce2S3couldbepreparedatthelowertemperatureandthebadlysinteredproductswereobtained;whenceriananoparticleswithlargesizewereemployedasprecursors,pureγ-Ce2S3wasdifficultlyobtainedevenifthetemperaturewasupto800°Candtheproductstendedtokeeptheiroriginalsize.Theheat-resistancepropertyoftheγ-Ce2S3withlargesizewasbetterthanthesmallerone,andthepureγ-Ce2S3preparedfromprecursorwithsmallsizehadagoodpigmentaryperformance.

  • 标签: 耐热性能 前体 扫描电子显微镜 颜料 形貌 二氧化铈
  • 简介:经过槽下系统的设备改造,实现了槽下过筛,入炉粉率降低,为一系列的技术进步提供了基础保障,阐述了各项生产技术进步与生产实践.

  • 标签: 高炉 槽下改造 入炉粉率 生产实践 炼铁
  • 简介:CeO2nanoparticles(nano-CeO2p)wereaddedintolasercladdedNiCoCrAlYcoatingsonNi-basedsuperalloysubstratetoimprovethemicrostructureandproperties.Scanningelectronmicroscope(SEM),X-raydiffractometer(XRD),micro-hardnesstester,andheattreatmentfurnacewereemployedtoinvestigatetheirmorphologies,phases,micro-hardnessandthermalshockresistance,comparedwiththecoatingwithoutnanoparticlesadded.Theresultsshowedthatthemicrostructureandpropertiesofthecoatingswiththeaddition...

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