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500 个结果
  • 简介:ZnOnanotubeswerehydrothermallysynthesizedandtheZNTs/CeO2fluorescentcompositewerepreparedbyintroducingnanoCeO2particlesintoZnOnano-tubesviaachemicalsolutionadsorptionandannealingprocess.ThesampleswerecharacterizedbyX-raydiffraction,scanningelectronmicroscopy,Fouriertransformationinfraredspectroscopyandroomtemperaturephotoluminescencemeasurement.DuetotheinteractionbetweenCe4+andthesurfaceatomsofZnO2nano-tubes,aphotoluminescenceenhancementwasobser...

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  • 简介:Withcoalgasasareducingagent,thecatalyticreductionofSO2tosulfurinthefluegasproducedinmetallurgicalprocesseswasstudiedovercatalystsofrareearth-Fe/Al2O3(REFe/Al2O3).ThecatalyticactivityoftheREFe/Al2O3catalystonthereductionofSO2tosul-furwasinvestigatedbasedonkindsandthecontentsofrareearthsanddifferentpreparationmethodofthecatalyst.Additionally,themecha-nismofthiscatalyticreductionreactionwasalsoexplored.ResultsshowedthatdifferentrareearthimposeddifferenteffectontheactivityoftheFe/Al2O3catalyst.Especially,theadditionofSmandDygreatlyimprovedthecatalyticactivityofFe/Al2O3.TheyieldofsulfuroverSmFe/Al2O3wasincreasedto86.62%at360℃,whichwas40.5%higherthanthatoverFe/Al2O3atthesametemperature;andthesulfuryieldoverDyFe/Al2O3wasincreasedto91.62%at400℃,26.4%higherthanthatoverFe/Al2O3.ThecatalyticactivityofREFe/Al2O3wassomehowdependentonthecontentofrareearth.ForSmFe/Al2O3,thecontentofSmwasoptimizedtobeabout1.0wt.%.Therareearthcatalystpreparedwithdifferentmethodsalsoshowedvariedactivity.Thesulfuryieldoverrare-earthtransitionmetalcatalystsfollowstheorder:SmandironsolutionmixingimpregnationSmfirst,thenironsolutionimpregnationironfirst,thenSmsolutionimpregnation.ThereactionmechanismofSO2reductiontosulfurwithcoalgaswasproposedtobeanintermediatemechanism.

  • 标签: SULFUR dioxide CATALYTIC REDUCTION SULFUR FLUE
  • 简介:介绍了利用可编程控制器和计算机技术对大功率SO2风机控制系统的改造,内容包括控制方案、系统软件方案、系统功能以及问题和对策.

  • 标签: SO2风机 PLC 工控机 触摸屏 PROFIBUS-DP MPI
  • 简介:针对方大特钢公司60Si2Mn弹簧扁钢产品出现剪切端面裂纹问题,进行裂纹检测、剪切温度试验和不同温度下力学性能检测;分析发现剪切时的温度对裂纹产生的影响,发现剪切裂纹是剪切应力作用于偏析较严重部位形成的裂纹源在残余应力释放过程扩展形成的横向裂纹.根据分析结果,在生产实践中分别对炼钢、轧制工序采取相应措施,有效控制了弹簧扁钢的剪切端面裂纹.

  • 标签: 弹簧扁钢 裂纹 剪切温度 偏析 原因分析
  • 简介:TheNd3+3.2%(atomfraction):KGd(WO4)2crystalwasgrownbyKyropoulosmethod.TheabsorptionspectrumandfluorescencespectrumofNd3+:KGWcrystalweremeasured.Theabsorptioncrosssectionsat808nm(0.6799×10-20cm2)werecalculated,andtheoutputwavelengthoffluorescenceis1064and1351nm.Thediode-pumpedlaserwasoperatedbothinthefree-runningandpassivelyQ-switchedoperatingmodes.Themaximumlaseroutput(1064nm)is326mWwith62.7%slopeefficiencywheninputenergyis900mW.ThebeamqualityfactorM2≈1.1.Thegreenlightof532nmisobtainedinfrequencydoublingoperation.ThelaserispassivelyQ-switchedbyusingCr4+:LuAGassaturableabsorber.Thepulsewidthis170nsatrepetitivefrequencyof15kHZ.

  • 标签: Nd : KGW晶体 晶体生长 LD泵浦 激光材料
  • 简介:Inaflowinjectionseparationandpreconcentrationsystemincorporatingamicrocolumn,theadsorptionbehavior(effectofpH,kineticadsorptioncapacity)ofmetalionsCu^2+,Cr^3+,Mn^2+,Ni^2+,La^3+,Eu^3+,Ga^3+,Mo(Ⅵ)andW(Ⅵ)onTiO2owderwithdifferentcrystalstructureandparticlediameterwasstudiedandcompared.Inaddition,theechanismoftheadsorptionofmetalionsonTiO2owderwasexplored.TheresultsshowthatcrystaltructureandparticlediameteroftheTi02powderwillefinitelyaffecttheadsorptioncapacityofmetalsont.

  • 标签: 二氧化钛粉末 吸收性质 金属离子 晶体结构 颗粒直径 稀土元素
  • 简介:TheNaGd(WO_4)_2:Eu~(3+)phosphorswerepreparedbythemicroemulsionmediatedhydrothermalmethod.ThemorphologyandsizeofthesamplescouldbedependentonthepHintheinitialsolution.Thesephosphorsobtainedhadastrongabsorptionat395nmmatchingwiththepopularemissionofnear-UVLEDchips,andcouldemitintenseredlightat616nm.Thesmallellipsoid-likeparticlesorshortrodswereprovidedwithlargeparametersofoscillatorstrength?_2andasymmetryratio.Comparedtotheellipsoid-likephosphors,therod-likephosphorstookonstrongeremission,longerlifetimeandlargerquantumefficiency.Thisworkdemonstratedthattheone-dimensionNaGd(WO_4)_2:Eu~(3+)phosphorsmightbeamorefavorabledevicethanzero-dimensiononesforphotoluminescence.

  • 标签: MICROEMULSION hydrothermal oscillator matching LIFETIME sizes
  • 简介:StudyontheEasyDirectionofMagnetizationofSm0.88Dy0.12FeAlloyZhuMingyuan(朱明源),ZhangHuiyou(张慧友),ZhuYuliang(诸于良)JinHongmin?..

  • 标签: Sm0. 88Dy0. 12Fe2 ALLOY EASY direction
  • 简介:离心式空气压缩机是目前工厂使用最普遍的空气压缩机,然而,离心式空气压缩机夏季较易发生喘振。本文简述了离心式空气压缩机的喘振机理、特征和危害,并针对夏季温度升高时如何预防离心式空气压缩机喘振以及如何提高其运行效率的措施进行了分析。

  • 标签: 喘振 离心式空压机 夏季 气温 效率 措施
  • 简介:为了解决某铜矿深井大断面配电硐稳定性问题,通过在现场对配电硐的工程地质情况进行调查,结合配电硐的服务年限及用途,提出了“喷射混凝土+钢网+锚杆+长锚索”的联合支护方案,运用有限差分软件FLAC-3D建立配电硐三维数值计算模型,模拟其开挖和支护过程。数值模拟计算结果表明,采用“喷射混凝土+钢网+锚杆+长锚索”的联合支护方案后,配电硐的塑性区面积明显减小,应力得到释放,围岩的稳定性得到有效控制,可为某铜矿大型配电硐进行支护提供一定的指导,对其它类似工程具有一定的借鉴意义。

  • 标签: 大断面硐室 稳定性 联合支护 有限差分法 数值模拟
  • 简介:ThispaperistodiscussthesensingcharacteristicsofSnO2semiconductorcomponentsinwhichPr6O11isadded.Whenexperimentingunder11gasesofCH3COCH3,C2H5OH.C6H5CH3,H2,NH3,CO,CO2CH4,C4H10,n—C6H14andn—C7H16,wefindthatthecomponentshaveselectivitytoCH3COCH3,C2H5OHandthattheidealamountofPr6O11inthecomponentsisaboutI.Owt%.TheexperimentsalsoshowthatwiththeincreaseoftheamountofPr6O11,theidealworkingtemperature,theresponseandrestorationtimedecrease.

  • 标签: gases SELECTIVITY restoration MONOXIDE methane AMMONIA
  • 简介:主要采用金相及SEM分析方法,对20Cr2Ni4A锻圆表面裂纹性质及产生原因进行了分析,结果表明锻圆表面裂纹是由于原材料存在表面夹杂/渣引起的。

  • 标签: 钢锭 锻造 纵向裂纹
  • 简介:钕铁硼系磁体的推出,使Sm_2Co_(17)磁体的市场规模大大减少。最近日本信越化学工业公司的研究表明,该磁体可以暴露于200℃以上的高温下,还可在氢气等特殊环境下使用。钕系列磁体用于大功率马达的情况下,由于周围环境及焦耳热使温度升高,产生的

  • 标签: 快淬 日本快 法生产