学科分类
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343 个结果
  • 简介:Eu-activatedCaMoO4phosphorswereco-precipitatedinanaqueoussolution,andNH3·H2O,NH4HCO3and(NH2)2COaspre-cipitatingaidagentswerecomparedbasedonthemorphologyandparticlesizedistributionofthephosphorsamples.Sm3+assensitizerionwasinvestigatedontheluminescenceofCaMoO4:Eu,anditcouldstrengthenthe406nmabsorptionofthisphosphor.Atlast,thescheeliteCaMoO4:EuandwolframiteZnMoO4:Euwereselectedtocomparetheirhostabsorption.TheresultshowedthatthescheelitemolybdatehostexhibitedstrongerUVabsorptionthanwolframiteone.

  • 标签: CaMoO4 ZnMoO4 EUROPIUM SAMARIUM red PHOSPHOR
  • 简介:本文通过对酒钢450m~3高炉料位计工作原理及工艺联锁功能的介绍,针对检测系统在日常生产中所存在的问题,从硬件和软件两方面对料位计及其联锁功能进行了完善和优化,提高了料位检测系统的稳定性和安全性。

  • 标签: 料位计 探头 射源
  • 简介:Thecoilingtemperatureofthehotstriprollingprocessplaysanimportantroleinstripqualitycontrol.Thenewly-builtlaminarflowcoolingcontrolsystemwasindependentlydevelopedbyBaosteel.L2conductstotallydynamiccontrol(L1onlyexecutestheresultfromL2,anddoesnotconductanydynamiccontrol).Thesystemhasmanyadvantages,suchasquickreal-timecontrol,accuratemodelcalculation,quickresponseafterself-adaptation,etc.Comparedwiththe2050mmhotstriprollingline,thenewsystemcansatisfythestrictcoolingrequirementsofhighstrengthsteel,siliconsteelandheavyplatesbecauseofitsnewly-developedtechnologiesofcoolingratecontrol,stripcoolingbysectionsandproportion-integral-differentialcoefficient(PID)feedbackfuzzycontrol.

  • 标签: 薄片 冷却控制 炼钢技术 冶炼技术
  • 简介:AseriesofMn-basedcatalysts,MnOx,MnOx-CeO2,Pd-Mn-Ce,MnOx/ACwereprepared.AndtheirperformancesforNOlow-temperatureSCRwereinvestigatedinthisstudy.TheNOconversionisabout90%at100℃onMnOx-CeO2andalmostallNOcanbeconvertedat120℃.SimilarresultsarealsoobservedinthetestsonMnOx-CeO2/AC.Theexcellentlow-temperaturecatalyticactivityofmodifiedMn-basedcatalysts,whichmaybemainlyduetotheoxygenstoragefunctionofCeO2,canimprovetheoxygenflowonthecatalystssurface.ThentheoxidationofNOtoNO2isaccelerated,whichisthekeystepofNOSCR.

  • 标签: LOW-TEMPERATURE SELECTIVE CATALYTIC reduction (SCR) NO
  • 简介:ThedopedZnOnanorodsasaphotocatalystwithdifferentEucontentswerepreparedbymicrowaveassistedmethodandtheywerecharacterizedbymeansofX-raydiffraction(XRD),energy-dispersiveX-rayspectroscopy(EDS),UV-Visspectroscopy,surfaceareaBrunauer-Emmett-Teller(BET),X-rayphotoelectronspectroscopy(XPS),scanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM).TheaveragecrystallitesizeandbandgapenergyofEu-dopedZnOwerevariedwiththeEucontent.TheXRDpatternofEu-dopedZnOindicatedhexagonalcrystalstructurewithanaveragecrystallitesizeof25nm.ThepresenceofeuropiumwithtrivalentstateanditsdopingsuccessfullyintothecrystallatticeofZnOmatrixwereconfirmedbyXPStechnique.ThephotocatalyticactivityofEu-dopedZnOnanorodswasevaluatedformethylorangedegradation.Thephotocatalyticexperimentsshowed~91%degradationofmethylorangeover0.2mol.%EudopedZnOsamplewithin3hunderUVlight(365nm).

  • 标签: 光催化活性 微波辅助 ZnO 纳米棒 铕掺杂 合成技术
  • 简介:系统地总结了南钢300m^3级高炉生产技术进步。近年来,炼铁厂通过改善原燃料质量,优化用料结构;实施技改技措,提高高炉装备水平;加强高炉操作,确保炉况稳定顺行;优化高炉工艺,进行强化冶炼;加强基础管理,确保高炉生产等措施,取得了良好的技术经济指标。

  • 标签: 高炉 生产 技术进步
  • 简介:NanosizedBaCeo.95Yo.o5O3-δpowderswiththehomogeneouscompositionweresynthesizedbyanewcombustionprocessbasedonthePechinimethod.Apolymericprecursorsolwasformedbyuseofcitricacidandethyleneglycolasthechelatingagentsofmetalions.Theperovskite-typeBaCeo.95Yo.o5O3-δpowderswithuniformshapeandsmallerthan40nminsizedwereobtainedthroughthecombustionofthepolymericprecursorsolattheexistenceofnitricacidandammoniumhydroxide.Itwasfoundtheparticlesizecouldbecontrolledbymodulatingthequantitiesofnitricacidandammoniumhydroxide,thequantitiesoftheresidue,carbonateionswerealsoaffectedbythequantitiesofthecitricacidandethyleneglycol.

  • 标签: 无机非金属纳米材料粉末 钙钛矿氧化物 BaCeo.95Yo.o5O3-δ 燃烧合成 稀土元素
  • 简介:承钢炼铁厂300m^2高炉液压炉顶不上钟油缸底座由于小钟与油缸活塞杆行程相差60mm,每天小钟开关频繁,各部位刚性连接,使油罐底座经常被损坏。将活塞杆与平衡臂连接销于曲φ100mm改为φ80mm;油缸底座的轴承套去掉;小钟行程调到670mm;关钟时间由原7s改为10s,但磨损仍较重。1995年9月第二座高炉小钟油缸底座改为滑块式,滑块行程65mm,小种行程调整到650mm,使用效果良好。

  • 标签: 高炉 液压炉顶 小钟 油缸 底座 炼铁
  • 简介:根据以往喷煤工程的经验,结合炼铁新厂3#高炉喷煤工艺特点,采用了模糊控制技术,提高了小时喷煤量的控制精度,提高了喷煤系统设备的安全性与稳定性,为高炉的稳定顺行、低能耗高产出创造了条件。

  • 标签: 高炉 模糊控制 喷煤量
  • 简介:YbF2.357,YbF3,Ba2YbF7,andBa2upconversionnanocrystalsdopedwithemitterEr3+ionweresynthesizedinthesamesolventsystemjustwithchangingthemolarratioofBa2+toYb3+intheprecursor,whichcorresponedtothecrystalphasesofrhombohedral,orthorhombic,tetragonal,andcubic,respectively.Allthesamplesemittedboth660nmredlightand543/523nmgreenlightwhichoriginatedfromEr3+-4fnelectronictransitions4F9/2-4I15/2and4S3/2/2H11/2-4I15/2,respectively.ItwasworthmentioningthatYbF3:Er3+,Ba2YbF7:Er3+,andBaF2:Er3+couldemitdazzlinglybrightlightevenundertheexcitationofa980nmCWlaserwithoutputpowerof0.1W.Upconversionemissionmechanismanalysisindicatedthattheintensityratioofredtogreenlighthighlydependedonthesynergisticeffectofcrystalstructure,concentrationquenching,andparticlesize,butwerenotsensitivetocrystallinityaspreviouslyreportedforNaLnF4(Ln=lanthanide).

  • 标签: 上转换发光 晶体结构 光致发光 浓度猝灭 纳米晶 协同效应
  • 简介:氪、氙是空气中的稀有气体,由于具有一定的特性,使氪、氙应用前景广泛,空分中存在多种稀有气体,其中氪、氙含量最少,由于提取工艺复杂,价位高昂,俗称"黄金气体",空分中的氪、氙主要在液氧中,通常伴随产品氧气或液氧排出而被带走,随着空分设备日益大型化,提取氪、氙的原料气液氧产能增加,从液氧中提取氪、氙蕴藏着巨大经济前景。

  • 标签: 制氧机氪 氙塔液氧碳氢化合物安全运行
  • 简介:SmOHCO3micro/nanoparticleswerepreparedinwater/oil(W/O)reversemicroemulsioncomposedofcetyltrimethylammoniumbromide(CTAB),n-octane,n-butanol,Sm(NO3)3·6H2Oandureaaqueoussolutionbythecouplingrouteofhomogeneousprecipitationwithmicroemulsion.ThenanoparticleswerecharacterizedandanalyzedbyX-raypowderdiffraction(XRD),thermalgravimetricanddifferentialthermalgravimetricanalysis(TG-DTG),Fouriertransforminfraredabsorptionspectra(FT-IR)andscanningelectronmicroscope(SEM).TheresultsshowedthatthephaseSmOHCO3micro/nanoparticleswasinagreementwithpureorthorhombicphase.ThedifferentmorphologiesofSmOHCO3micro/nanoparticleswithgoodmonodispersityandsizewereobtainedbyregulatingthereactiontemperatureandreactiontime.PossibleformationmechanismsofthemorphologicalstructureofSmOHCO3wereproposedanddiscussed.

  • 标签: 反相微乳液 纳米颗粒 均相沉淀 耦合途径 十六烷基三甲基溴化铵 X射线粉末衍射
  • 简介:介绍了南钢2500m^3高炉专家系统的开发过程、主要模型功能及应用情况,指出了专家系统在应用中体现出来的优点和存在的不足之处。

  • 标签: 高炉 专家系统 功能 应用
  • 简介:3^#汽轮鼓风机运行近一年后连续发生断风事故,机组处于喘振工况区工作,其原因是大量的尘垢粘附在风机叶片上,引起叶型的改变。

  • 标签: 汽轮鼓风机 断风 事故分析 高炉 炼铁
  • 简介:Athree-dimensionalmathematicalmodelofthecombustionofpulverizedcoalandcokehasbeendeveloped.Themodelisappliedtotheblowpipe-tuyere-raceway-cokebedregioninanironmakingblastfurnaceinonecomputationaldomain,whichincludestwoparts:pulverizedcoalcombustionmodelintheblowpipe-tuyere-racewaycavityandthecoal/cokecombustionmodelinthesurroundingcokebed.Theeffectsofcoalpropertiesareexaminedcomprehensively,intermsofcoalburnoutandgasspeciesdistributions.TheresultsindicatethatusingacoaloffineparticlesizeorhighVMcontentcouldimproveburnoutandwouldaffectthegascompositionconsiderably.Theburnoutisexaminedintwoways:comparedwithburnoutalongtuyereaxis,burnoutovertheracewaysurfaceisamoresensitiveandsensibleparametertodescribetheamountofunburntcharenteringthecokebed.Themodelisusefulforexaminingtheflow-thermo-chemicalcharacteristicsofthepulverizedcoalinjection(PCI)processundervariousconditionsinablastfurnace.

  • 标签:
  • 简介:采用喷雾造粒制备Fe2O3空心球团粒,团粒经过氢气还原得到中空Fe颗粒,通过扫描电镜(SEM)观察Fe2O3空心球团粒及其截面的形貌,研究还原时间对Fe颗粒形貌与截面形貌的影响;采用激光衍射粒度分析仪对Fe颗粒进行粒径分析;采用比表面及孔隙度分析仪表征Fe颗粒的比表面积;采用CSM-MCT显微硬度仪测量空心球状Fe颗粒球壁的硬度和弹性模量。结果表明:Fe2O3空心球团粒和Fe颗粒均为多孔中空球状结构,球壁上存在大量微孔,中空孔直径和球颗粒直径的比值在0.4~0.5;在650℃下还原,随着还原时间增加(4,5,6h),球壁晶粒逐步长大,中空球状Fe颗粒的比表面积和粒径逐步减小,球壁趋向致密,硬度和弹性模量提高。

  • 标签: 喷雾造粒 中空球状结构 Fe颗粒 制备与表征 力学性能