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192 个结果
  • 简介:发动冷却系统的作用是保证发动在最为适宜的温度范围内工作。当发动冷却系统发生故障时,发动会过热或过冷,以致产生发动功率下降、燃油消耗率增加和工作不平稳等不良现象,严重时产生受力零件损坏、活塞卡缸或拉缸等现象。康明斯QSK60冷却系统采用双泵双循环回路结构,通过阐述其工作原理,结合工作中实践经验,对冷却系统故障的原因进行分析并提出相应的检修方法。

  • 标签: QSK60发动机 冷却系统 工作原理 故障分析 检修方法
  • 简介:本文详细地介绍了在发动修理过程中,遇到曲轴的油封接触表面出现过度磨损情况,导致发动运行时存在不同程度的润滑油泄漏故障,通过分析不同的曲轴油封结构及磨损程度,采取了直接修磨、油封错位安装、安装耐磨套等方法,经过跟踪发动修理运行使用情况,效果良好。

  • 标签: 发动机 曲轴 油封 磨损 处理
  • 简介:依据毛坯特点,零件产量与加工要求,自定刃具,巧妙安排加工工艺,打破传统加工工艺思路,通过创新工艺安排,即保证了加工质量,提高了产量,还降低了操作员难度,可为工艺人员提供一种设计思路。

  • 标签: 加工工艺 夹具 车床加工
  • 简介:通过制作两个固-液扩散偶,并通过实验探索700℃下Fe-Zn-Sn系中不同成分制备平衡合金的方法,利用SEM-EDS等手段测定Fe-Zn-Sn三元系700℃等温截面部分相关系。实验结果显示:这部分相图是由L、α(Fe)、Γ三个单相区,L+α(Fe)、FeSn+Fe3Sn2、Γ+Fe3Sn2、L+FeSn、L+Γ、α(Fe)+Γ六个两相区,α(Fe)+L+Γ、α(Fe)+L+Γ、L+FeSn+Fe3Sn2三个三相区组成的;锡含量在一定范围内,锡含量的增加导致镀层厚度减少。

  • 标签: Fe-Zn-Sn 等温截面 相图 热浸镀锌
  • 简介:浙江升华强磁材料有限公司为了满足国内电机行业快速发展的需求,投资700多万元,加快实施高牌号钕铁硼磁性材料扩产项目(月产45吨)。据悉,该项目将于2007年3月中旬投入试生产。

  • 标签: 钕铁硼磁性材料 扩产项目 投资 强磁 电机行业 磁材料
  • 简介:在达到一定勘查程度的金矿区,有条件的合理利用部分D级储量作为矿山建设依据,可以减少投资风险,保障黄金生产稳步发展。

  • 标签: 黄金 D级储量 利用
  • 简介:Loadedonthecordierite,therareearthdopedcompositecatalystwaspreparedbysol-gelmethodcombinedwithdippingtechnique.TakingOrthodichlorobenzeneasmodel,thecatalystwasusedtoremovethedioxinsofthewastegas.Theresultsshowedthatat280℃andgasspacevelocitybeing8000h-1,theorthodichlorobenzenecouldberemovedeffectivilybythepreparedCeO2-TiO2-V2O5compositecatalystwhoseactivitywasremarkablyenhancedbythedopingofCe,whiletheindustrialside-streamtestofdioxinsfromrefuseincinerationsmokeindicatedthatthedecompositionratecouldreachabove93%underthesameconditions.

  • 标签: orthodichlorobenzene DIOXINS CATALYTIC oxidation REFUSE INCINERATION
  • 简介:Inthiswork,boththethermalexpansionandelectricalconductivityofnanocrystallineLa2Mo2O9werestudied.ThenanocrystallinepowderofLa2Mo2O9wasobtainedbysol-gelmethod,andwiththehelpofSHP(superhighpressure)upto4.5×104atmat700℃forashorttime,andthenanocrystallinepowderwasdensifiedwithoutobviousparticlesizegrowth.TheelectricalconductivityofnanocrystallineLa2Mo2O9wasoneorderofmagnitudelowerthanthatofthemicrocrystallinesampleatthesametemperature.Owingtothephasetransition,themicrocrystallineLa2Mo2O9hasanabruptincreaseofthermalexpansionwithapeakvalueof48×10-6K-1at556℃.Forthenanocrystallinematerial,thepeakvalueincreasesto112×10-6K-1at520℃.Ontheotherhand,above600℃thesignificantgrowthofparticlesizeofthenanocrystallineLa2Mo2O9wasobserved,accompanyingbyatremendousincreaseofthermalexpansionwithapeakvalueofthirdhigherthanthatofLa2Mo2O9.

  • 标签: NANOCRYSTALLINE electrical CONDUCTIVITY LANTHANUM MOLYBDATE superhigh
  • 简介:Basedonthethermodynamicallyself-consistentanalysisandoptimizationofthreesub-binarysystemsoftheternarysystemPrCl3-CaCl2-MgCl2,thethermodynamicsofthisternarysystemhasbeenstudied.UsingHillertmodelandtakingMgCl2asanasymmetriccomponent,thePrCl3-CaCl2-MgCl2phasediagramhasbeencalculated.Theagreementbetweencalculatedandmeasuredcompositionsandtemperaturesatdeflectingpointsonliquidusisgood.Thesystemisasimpleeutecticonewithaeutecticpointat26.0mol%PrCl3,41.5mol%CaCl2,32.5mol%MgCl2;560℃(calculated)and26.0mol%PrCl3,39.4mol%CaCl2,34.6mol%MgCl2;546℃(measured),respectively.

  • 标签: TERNARY system Phase DIAGRAM Rare earth
  • 简介:TheZrO2-Al2O3ceramiccompositeswerepreparedbyappropriatetechniqueswithcommercialZrO2andAl2O3powdersasrawmaterialsandY2O3asstabilizer.TheresultsindicatethatwiththeintroductionofAl2O3intotheZrO2matrixwherethequantityofadditiveY2O3is3.5%(molefraction),thegrowthofZrO2grainsisefficientlyinhibited,whichhelpstheZrO2grainsexistinametastabletetragonalmanner;thushigherstrengthandtoughnessareacquired.Whenthecontentofaluminais20%(massfraction),thebendingstrengthandfracturetoughnessofthecompositesare676.7MPaand10MPa·m1/2respectively,themechanicalbehaviorsareclosetothosepreparedwithZrO2andAl2O3powderssynthesizedthroughwetchemicalapproach.Themechanicalbehaviorsofthecompositesarewellimprovedowingtothedispersiontougheningofaluminagrainsandphasetransformationtougheningofzirconiagrains.

  • 标签: 无机非金属材料 陶瓷 稳定设备 稀土
  • 简介:Differentrareearth(RE)ionsdopantswereaddedintotheSrAl2SiO7:Eu2+phosphorsinordertoenhancethephosphorescenceproperties,andtheeffectoftheREionsincludingYb3+,Ce3+,Nd3+,Dy3+andTm3+,wascomparativelyinvestigated.ItwasfoundthatNd3+additionimprovedthephosphorescencepropertiesobviouslyamongallthestudiedREions.Therefore,Sr1.96–xAl2SiO7:xEu2+,yNd3+phosphorswerestudiedindetail,andtheoptimumEu2+andNd3+concentrationsweredeterminedwiththeafterglowtimeofabout20min.Thephasestructures,photoluminescence(PL)properties,long-lastingphosphorescence(LLP)properties,afterglowdecaycurvesandthermo-luminescence(TL)fortheselectedphosphorsduringthecorrespondingstudywereinvestigated.AllthephosphorsexhibitedgreenPLemissionandLLPemission.ThereweretwoTLbandslocatedatabout325and380Kforthestudiedsamples,andtherelationshipbetweenREadditionandphosphorescencepropertieswasdiscussed.

  • 标签: 稀土掺杂 光性质 荧光粉 磷光 欧盟 稀土离子
  • 简介:FluorescencespectraofSm2+andEu2+→Sm2+energytransferwerestudiedinSrB4O7.Thereappearsonlyfluorescencefrom5D0transitionofSm2+at77K.Thevibroniclinesassociatedwith5D0→7F0transitionwereobserved.Thethermalpopulationtoupperstatesof5D1and4f5dlevelsfrom5D0givesriseto5D1→7FJand5d→4fradiativetransitionsofSin2+athighertemperature.

  • 标签: Strontium-samarium BORATE Energy transfer ELECTRON-PHONON interaction
  • 简介:Reactionof(MeC5H4)3LnwithHOCH2CH2NMe2intetrahydrofuran(THF)givesthenewcomplexes[(MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln=Sm,Y,Nd)withnitrogenfunctionalizedμ-alkoxideligand.ThecomplexeswerecharacterizedbyelementalanalysisandIR,and[(MeC5H4)2Sm(μ-OCH2CH2NMe2)]2wasstructurallycharacterizedbytheX-raydiffractiontobeadimerformedbytwounsymmetricoxygenbridges.ThecomplexhasatricyclicskeletonwiththeadditionaltwoSm-NbondsviaintramolecularcoordinationofOCH2CH2NMe2.ThecoordinationnumberofthecentralmetalSmisnine.Thetitlecomplexesshowgoodcatalyticactivityforring-openingpolymerizationofε-caprolactone.

  • 标签: 2 晶体结构 合成 镧系元素 ε-已内酯 聚合
  • 简介:增加的CeO2(ZrO2)/TiO2催化剂独立由大音阶的第五音胶化和受精的方法准备了的一系列镨为选择催化减小被测试没有,并且由X光检查衍射(XRD)描绘了,N2-brumauer-emmett-teller(N2-BET),NH3-temperature规划了解吸附作用(NH3-TPD),H2-temperature规划了减小(H2-TPR),PL系列,拉曼系列,电子顺磁的回声(EPR)一催化性能上的准备方法的影响被学习。结果证明CeO2(ZrO2)/TiO2催化剂的催化性能上的Pr增加的影响在大音阶的第五音胶化方法和受精方法之间是不同的。Pr增加趋于与TiO2交往并且当它是更可能的与在受精方法形成Ce-O-Pr的结构的CeO2交往时,在大音阶的第五音胶化方法形成了Ti-O-Pr的结构。大音阶的第五音胶化方法准备的催化剂的全部的酸数量和氧化还原作用性质与Pr元素的增加减少了,它导致了催化活动的减少。相反,受精方法准备的增加Pr的催化剂被发现拥有更容易的reducibility,更多的全部的酸数量和Ce3+种类的更高的比例,它为更高催化的活动是赞成的。

  • 标签: 增加镨 CeO 2(ZrO2)/TiO2 准备方法 选择催化减小 催化性能 稀土元素
  • 简介:在甲烷(POM)的部分氧化的催化活动和稳定性混合方法的CeO2-ZrO2和-Al2O3的影响在Ni/Ce0.7Zr0.3O2-Al2O3催化剂上被调查。催化剂被XRD,TPR,H2-chemsorption,和TG-DTA描绘。为新鲜催化剂,结果证明混合催化剂(原子)的盐先锋比混合方法(摩尔)和机械地混合方法(MECH)的粉末的催促的人准备的催化剂介绍了更好的性能。XRD的结果建议在在原子样品的CeO2-ZrO2和Al2O3之间的相互作用比其它强壮,它导致了更多的格子缺点和从而更好的起始的活动。而且,MECH样品在24h稳定性测试有最好的稳定性和最少的焦炭免职。TPR和H2-chemsorption的结果显示在MECH样品的Ni-Al的亲密接触提高了抵抗焦炭免职和金属sintering的能力。

  • 标签: CEO2-ZRO2 Γ-AL2O3 催化剂 稀土
  • 简介:Inthispaper,varioustechniquesincludingBET,XRD,SEMandXPSwereusedtostudythesinteringofpureandLa2O3-dopedtitania.Theexperimentalresultsshowthatsinteringoftitaniaproceedsviavolumediffu-sion.Addingoflanthanumoxidedecreasestherateofsinteringandhindersthephasetransitionfromanatasetorutilecrystalbystrongsurfaceinteractionbetweenthemixedcrystals(La4Ti9O24,La0.66TiO2.99)andTiO2.

  • 标签: La2O3 TiO2 SINTERING kinetics Thermal stability
  • 简介:Ni-W-P-CeO2-SiO2nano-compositecoatingswerepreparedonthecarbonsteelsurfacebypulseco-depositionofnickel,tungsten,phosphorus,nano-CeO2andnano-SiO2particles.Theinfluenceofnano-SiO2particlesconcentrationsinelectrolyteonmicrostructuresandpropertiesofthenano-compositecoatingswereresearched,andthecharacteristicswereassessedbychemicalcompositions,elementdistribution,depositionrate,microhardnessandmicrostructures.Theresultsindicatethatwhennano-SiO2particlesconcentrationsinelectrolytearecontrolledat20g·L-1,thedepositionratewith27.07μm·h-1andthemicrohardnesswith666Hvofthenano-compositecoatingsarehighest,elementlinescanningandareascanninganalysesshowthattheaveragecontentsofelementsW,P,SiandCeinthenano-compositecoatingsareclose,displayingthatthedistributionofeveryelementwithinthenano-compositecoatingsiseven.Anincreaseinnano-SiO2particlesconcentrationsinelectrolyte(whenlowerthan20g·L-1)leadstorefinementingrainstructureofnano-compositecoatings,butwhenitimprovedto30g·L-1,thecrystallitesizesincreaseagainandinthemeantimetherearealotofsmallbosswithnodulationshapeappearingonthesurfaceofnano-compositecoatings.

  • 标签: pulse electrodepositon NANO-COMPOSITE coatings deposition rate
  • 简介:Ca8Mg(SiO4)4Cl2:Eu2+phosphordopedwithSr2+cationforCa2+partially,wassynthesizedbysolid-statereactionathightemperatureunderreducingatmosphere,anditsluminescentpropertieswereinvestigated.TheexperimentalresultsindicatethattheemissionintensityofthephosphorincreasesafterbeingdopedwithafewamountofSr2+ion.Theemissionpeakofthephosphorblueshifttoabout464nmwhenthephosphorisdopedwithlargequantityofSr2+ions.TheexcitationspectrumindicatesthatthephosphorcanbewellexcitedbyUVandbluelightfrom300to460nm,andthephosphorwasfittedwellfortheexcitationbyUVorblue-LED.

  • 标签: CALCIUM MAGNESIUM chlorosilicate Eu2+ emission SPECTRUM
  • 简介:作为报导Y2O2S的改进:Tb3+,白光的长持续的黄磷:Y2O2S:Tb3+,Sm3+被准备由固态反应。光致发光系列证明在紫外刺激下面的Tb3+和Sm3+排出物的位置和形状在这位主人是类似的,它在不同刺激下面保证了一种稳定的白排放颜色(IEC的日光标准)。共同做的样品的腐烂曲线显示二个离子的排出物的腐烂时间是靠近的。热照明测量建议做的Sm3+离子创造的陷井是有用的推迟共同做的样品的白晚霞。因此,共同做的Sm3+离子的功能作为改进样品的白排放颜色并且充当新陷井中心被证实。

  • 标签: 白色 无机发光材料 稀土