学科分类
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220 个结果
  • 简介:通过分析三钢200m^2烧结机的点火现状及原因,提出了低负压点火烧结技术的改造方案。生产实践表明:改造后烧结料层厚度提高了54mm,烧结矿产量增加了4t/h,点火煤气消耗降低了159m^3/h,取得了良好的经济效益。

  • 标签: 烧结机 低负压点火烧结 改造 效益分析
  • 简介:Er~(3+)andLa~(3+)codopedY_2O_3nanocrystallinepowdersweresynthesizedbygelcombustionmethodandcharacterizedwiththermalanalysis,X-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),high-resolutionTEM(HRTEM)techniquesandfluorescencespectroscopy.Afterbeingcalcinedat1200oC,the(Y_(1–x)La_x)_2O_3:Er~(3+)powderswereconfirmedtobecubicY_2O_3phasewiththecrystallinegrainsizeintherangeof20–40nm.TheEr~(3+)emissionat1.53μmfromthe~4I_(13/2)→~4I_(15/2)transitionwasobserved,whichwasfoundtobeenhancedbyintroducingLa~(3+)ions.SuchenhancementcouldbeattributedtotheadjustmentofEr~(3+)ions'localenvironmentbythecodopingofLa~(3+)ions,leadingtotheincreasedgroundstateabsorptioncrosssectionofEr~(3+)ions.

  • 标签: POWDERS IONS crystalline CALCINED attributed cubic
  • 简介:铟生产废水中含锌砷镉杂质较高,且含有机物的酸性溶液。铟生产废水处理过程中,首先用纯碱中和废水,至pH值为8左右,大部分杂质沉入中和渣中;然后用硫酸亚铁和双氧水净化,废水达到国家工业排水一级标准。废水处理后进行了回用,实现了零排放,锌富集到中和渣,回收利用。处理过程没有废气产生,工序简单,安全环保。

  • 标签: 废水 中和 净化 回收 环保
  • 简介:EffectsofNbandZrsubstitutionsonthecrystal]izationbehaviorsandmagneticpropertiesofmelt-spun(Nd,Pr)2Fe14B/α-Fealloyswerestudied.Theresultsshowthatfor(Nd0.4Pr0.6)8.5Fe85.5B6ribbons,themetastable(Nd,Pr)3Fe62B14precipitatesaftertheinitialcrystallizationofα-Feanddecomposesintothefinalmixtureof(Nd,Pr)2Fe14Bandα-Fe.For(Nd0.4Pr0.6)8.5Fe84.5Zr0.5Nb0.5B6ribbons,however,(Nd,Pr)2Fe14Bandα-Fephasesprecipitatesimultaneously.ThisindicatesthatbothNbandZrdopingcanavoidtheformationofmetastablephaseand!

  • 标签: 稀土 磁性材料 磁力结构
  • 简介:针对GKD2型内燃机车电空接触器存在的烧损故障问题,结合电空接触器结构特点和电路原理从理论上进行了分析,提出了相应的改进措施和建议,保证了电空接触器无电状态下闭合和分断。对电空接触器触头的技术状态进行测试,开距、超程、压力和研距控制在规定的范围内,为确保机车正常运用发挥了重要作用。

  • 标签: 电力机车 电空接触器 烧损故障原因分析 措施 改进预防
  • 简介:TheextractionofCe(Ⅳ)inH2SO4/H3PO4systemwasinvestigatedsystematicallyusingbifunctionalionicliquidextractants(Bif-ILES)[A336][P507],[A336][P204]and[A336][C272]inn-heptane.TheeffectsofH2SO4concentration,extractantconcentrationandsalting-outagentconcentrationwereobservedindetail.TheextractionmechanismofCe(Ⅳ)inH2SO4/H3PO4systemwasobtained.ThecomparisonwithotherextractantssuchasCyanex923,TBPwasalsostudied.Thermodynamicfunctionsoftheextractionreactionwerecalculated,showingthattheextractionwasanexothermicprocess.TheseparationofCe(Ⅳ)fromRE(Ⅲ)andTh(Ⅳ)wasalsoinvestigated.TheresultindicatedthatCe(Ⅳ)couldbeselectivelyextractedinthissystem.CePO4nanoparticleswereobtainedintheprocessofstrippingusingH2O2inH2SO4/H3PO4system.X-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andspectroscopywereadoptedforthecharacterizationofthesample.

  • 标签: 萃取机制 离子液体 萃取剂 系统 双功能 Cyanex923
  • 简介:海关统计表明,1~7月,内蒙古自治区出口稀土2562.6吨,同比增加1.6倍,占同期我国稀土出口总量的23.6%;价值3106.2万美元,下降了0.2%,占同期出口总值的12.4%;出口均价每吨1.2万美元,下跌61.3%。全部以一般贸易方式出口;企业包括外商投资企业、私营企业和国有企业。

  • 标签: 内蒙古自治区 出口量 稀土 外商投资企业 贸易方式 国有企业
  • 简介:15%Ag-addedcubicperovskitesSr0.9La0.1TiO3andRuddlesden-Popper(RP)phasesSr2.7La0.3Ti2O7werefabricatedviahydrothermalsynthesis,coldpressingandhigh-temperaturesintering.Thestructureandthermoelectricpropertieswerealsoinvestigatedforallsamples.TheresultsindicatedthatAgprecipitatedasasecondphase.AgadditionmadeelectricalconductivityandabsoluteSeebeckcoefficientenhanced,asaresult,theZTvalueswereenhancedbothfortwoseries.Comparedwithcubicperovskite,RPphasewassubjectedtosmallerimpactbyAgaddition.ThereasonsforenhancingZTvalueandthedifferentimpactfortwoseriesbyAgadditionwerealsodiscussed.

  • 标签: 热电性能 SEEBECK系数 Ag 钙钛矿相 水热合成法 高温烧结
  • 简介:(Cu60Zr30Ti10)98Y2bulkmetallicglass(Φ4mm×70mm)wasobtainedsuccessfullybycoppermouldcoolingandspraying-casting,andsomesampleswereisothermallyannealedattemperaturesof473and623K,whichwaslowerthantheglasstransitiontemperature(Tg)for1h.Microstructureandpropertiesofas-castandannealedsampleswerestudied.Crystallizationphases(Cu10Zr7andCuZr)wereobservedinannealedsamples,andthespeciesandfractionofthesephasesincreasedwithincreasingannealingtemperature.Mic...

  • 标签:
  • 简介:Selectivecatalyticoxidation(SCO)ofammoniawascarriedoutoverCu-MncompoundscatalystsmodifiedwithtrivalentrareearthoxideCe2O3andLa2O3respectively.TiO2wasusedassupportanddifferentratioofO2weretestedinordertofindanappropriateO2concentration(vol.%),andtheresultsshowedthat1%O2(vol.%)waspropitioustoSCOofammonia.TheeffectsofthetworareearthoxidesmodifiedcatalystsCe2O3-Cu-Mn/TiO2andLa2O3-Cu-Mn/TiO2onthecatalyticactivityandselectivityofammoniaoxidationwereinvestigatedunderthereactionconditionof500ppmammonia,1%O2(vol.%),atthetemperaturefrom125to250oC.TheresultsrevealedthebeneficialroleofCe2O3andLa2O3incatalyticactivityatlowtemperatureandleanoxygenconcentration,whilethemodificationwithCe2O3andLa2O3ledtothenegativeinfluenceonN2selectivity.ForthecatalystsmodifiedwithCeshowedlowerNOandN2OselectivitythanthecatalystsmodifiedwithLa,thentheeffectsofdifferentCeloadingsoncatalyticactivityandselectivitywerealsoconsidered,incombinationwithcatalystspreparationmethods,whichincludeincipientwetimpregnation,sol-gelmethodandco-precipitation.Resultsrevealedthatthecatalystspreparedbysol-gelmethodobtainedpreferablecatalyticactivitycomparedwiththeothers,reaching99%ammoniaat200oC,whereas96%NOwasdetected.Italsoindicatedthatdifferentcatalystpreparationmethodsignificantlydeterminedproductiondistribution.

  • 标签: AMMONIA selective CATALYTIC oxidation (SCO) rare
  • 简介:太原钢铁集团公司和成都无缝钢管公司双方利用各自装备优势,通过合作解决了生产大口径不锈钢冷拔无缝钢管的关键-大型不锈钢管坯和热穿孔。详细介绍了Φ180×15冷拔不锈钢无缝管的管坯制造、热穿孔、冷拔(扩)、热处理等生产工艺和产品的良好市场前景。

  • 标签: 大口径 不锈钢 冷拔 穿孔 无缝管钢开发
  • 简介:一系列立方的稀土元素sesquioxidesRE2O3的拉曼系列(RE=Eu,Gd,Dy,惊讶,嗯,Tm,Yb,陆,Sc和Y)被拉曼光谱学与532和785根nm激光线调查。丰富的另外的乐队由于激光激动的光被观察。为Eu2O3,Dy2O3,Ho2O3,Er2O3,Tm2O3和Yb2O3,,光主要为Gd2O3,Lu2O3,Sc2O3和Y2O3来自内在的三价的lanthanide离子,他们的光被归因于象Eu3+,Nd3+和Er3+那样的另外的光lanthanide离子的踪迹杂质。这调查为检测踪迹作为一个有用工具证实了拉曼光谱学光lanthanide杂质。

  • 标签: 激光激发荧光 RE2O3 拉曼光谱仪 杂质分析 氧化铕 氧化铒
  • 简介:NominalcompositionofCa1-xZnxTiO3:0.002Pr3+(x=0.000~0.200)phosphorswerepreparedbyconventionalsolidreactionroute.XRDandPLmeasurementswereusedtoinvestigatethesolid-solutionstructureandluminescencepropertiesofZn-dopedCa1-xZnxTiO3:0.002Pr3+phosphors.Theeffectofsolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionsontheluminescentpropertieswasanalyzed.Theresultsrevealthat,withtheincreaseofZnsubstitutioncontentbelow0.010,latticeparametersandtheintensityofexcitationpeakatboth260and330nmaswellasthecorresponding610nmemissionintensityaremonotonouslydecreasedquicklyinasimilartendency.Also,theevolutionofluminescenceintensityandcrystalcellparametersagainstZndopingconcentrationareingoodagreement.AboveresultsarecloselyrelatedwiththestructurechangewithinCa1-xZnxTiO3:0.002Pr3+solid-solutionphaseformedbytheZnionssubstitutionfortheCasites.Presentstudyrevealsthatthesolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionshassignificanteffectontheluminescencepropertiesofsinglephaseCa1-xZnxTiO3:0.002Pr3+phosphors.

  • 标签: Ca1-xZnxTiO3 固溶体 发光性能 稀土 掺杂 荧光材料
  • 简介:ThephaseandmorphologytransformationduringthehydrothermaltreatingprocessofY2O3wasevaluatedwithX-raydiffcrcnce(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),particlesizeandspecificsurfaceareadetermination.TheresultsshowedthatthecubicY2O3didnottransferintohexagonalY(OH)3inpurewater.Therefore,purehexagonalY(OH)3withnanotubeandmicrorodmorphologieswereobtainedbyhydrothermaltreatingY2O3at150℃for12hin15mlof2mol/LNaOHsolutionwithandwith-outPVAorPEGItwassuggestedthatthecharacteristicpreferentialgrowthofY(OH)3wasattributedtothestructureanisotropyofhexahedronY(OH)3.TheadditionofPVAorPEGcouldpromotetheformingprocessofnanotubesbyselectiveadsorptionondifferentcrystalplanes,whichalteredthegrowthratealongdifferentdirectionsandresultedinthediffusionlimitofconstructingionsinthecentertopofrods.Finally,Y(OH)3:EuandY2O3:Eunanotubeswerealsosynthesizedbyusingthismethod,andtheirphotoluminescencepropertieswereevaluated.

  • 标签: HYDROTHERMAL synthesis Y(OH)3 Y(OH)3:Eu Y2O3:Eu NANOTUBE
  • 简介:MeltspinningtechnologywasusedtopreparetheMg2Ni-type(Mg24Ni10Cu2)100–xNdx(x=0,5,10,15,20)alloysinordertoobtainananocrystallineandamorphousstructure.TheeffectsofNdcontentandspinningrateonthestructuresandelectrochemicalhydrogenstorageperformancesofthealloyswereinvestigated.ThestructurecharacterizationsofX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM)andscanningelectronmicroscopy(SEM)linkedwithenergydispersivespectroscopy(EDS)revealedthattheas-spunNd-freealloydisplayedanentirenanocrystallinestructure,whereastheas-spunNd-addedalloysheldananocrystallineandamorphousstructureandthedegreeofamorphizationvisiblyincreasedwiththerisingofNdcontentandspinningrate,suggestingthattheadditionofNdfacilitatedtheglassformingoftheMg2Ni-typealloy.TheelectrochemicalmeasurementsindicatedthattheadditionofNdandmeltspinningimprovedtheelectrochemicalhydrogenstorageperformancesofthealloyssignificantly.Thedischargecapacitiesoftheas-castandspunalloysexhibitedmaximumvalueswhenNdcontentwasx=10,whichwere86.4,200.5,266.3,402.5and452.8mAh/gcorrespondingtothespinningrateof0(As-castwasdefinedasthespinningrateof0m/s),10,20,30and40m/s,respectively.Thecyclestability(S20,thecapacitymaintainrateat20thcycle)oftheas-castalloyalwaysrosewiththeincreasingofNdcontent,andthoseoftheas-spunalloysexhibitedthemaximumvaluesforNdcontentx=10,whichwere77.9%,83.4%89.2%and89.7%,correspondingtothespinningrateof10,20,30and40m/s,respectively.

  • 标签: 电化学测试 铸态合金 储氢性能 纳米晶体 NDX 非晶化
  • 简介:Whitelight-emittingYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswithordermorphologyandwellcrystallizationwerehydrothermallysynthesizedat180°C.Themicrostructure,white-lightemission,andlight-emittingmechanismofthepowderswerecarefullystudiedusingX-raydiffractometry,scanningelectronmicroscopyandphotoluminescencespectra.TheexcitationandemissionspectraofthephosphorpowdersindicatedthecoexistenceofefficientenergytransferfromEu~(3+)toDy~(3+)andinefficientenergytransferfromDy~(3+)toEu~(3+)besidestheenergytransferfromVO_4~(3–)toEu~(3+).IncreasingtheEu~(~(3+))concentrationinitiallyenhancedandthenweakenedtheluminescentintensityofDy~(3+).Thewhite-lightemissionsofYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswerebothrelatedtotheenergytransferbetweenVO_4~(3–)andDy~(3+)/Eu~(3+),aswellasbetweenEu~(3+)andDy~(3+).TheinefficientenergytransferfromDy~(3+)toEu~(3+)wasfirstfound.

  • 标签: POWDERS PHOSPHOR DIFFRACTOMETRY coexistence luminescent excitation