简介:有5-8nm的尺寸的做Eu的GaOOHnanoparticles被热水的方法作为表面活化剂用钠dodecylbenzenesulfonate(SDBS)准备。做Eu的-Ga2O3和-Ga2O3被退火进一步制作GaOOH:Eu然后由X光检查衍射(XRD)描绘了,传播电子显微镜学(TEM)和光致发光(PL)。TEM结果显示出那monodisperse做Eu3+的GaOOHnanoparticles形式然后变换进通过退火的做Eu3+的-Ga2O3和-Ga2O3GaOOH:在600和900点的Eunanoparticles?????????????????@
简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.
简介:采用固相法制备La2O3与Sb2O3掺杂的钛酸锶钡陶瓷,研究其介电性能及相变特性。通过X射线衍射法分析体系微观结构并利用扫描电镜观察其表面微观形貌。(La,Sb)共掺杂的钛酸锶钡陶瓷具有典型的钙钛矿结构,且随着Sb2O3掺杂量的增多其平均粒径显著减小。La3+离子以及Sb3+离子均占据钙钛矿晶格的A位。La2O3与Sb2O3添加量的改变显著影响钛酸锶钡基陶瓷的介电常数以及介电损耗。La2O3改性的钛酸锶钡陶瓷其四方-立方相变为二级相变,且居里温度随着La2O3掺杂量的增多向低温方向移动。(La,Sb)共掺杂的钛酸锶钡陶瓷则体现为弥散相变,随着Sb2O3含量的增大而偏离居里-外斯定律越显著。由于Sb3+离子对晶格原位离子的取代使得(La,Sb)共掺杂的钛酸锶钡陶瓷的介电常数最大值下的温度亦随着Sb2O3含量的增大而降低。
简介:ElectrocrystallizationMechanismofTungsteninMoltenKF-B_2O_3-K_2WO_4WenZhenhuanandLiGuoxun文振环,李国勋(GeneralResearchInstiiuteforNo...
简介:TiO2nanoparticleswithdifferentphasesarepreparedbyhydrolysisoftitaniumtetrabutoxideinthepresenceofHCl.ThecompositionandmicrostructureoftheresultingsamplesarestudiedbyXRDandTEM.TheseresultsshowthattherangeofparticlesizeofTiO2isfrom20to30nm.ThemechanismofTiO2photocatalysisreactionhasbeendiscussedextensively.PhotocatalyticactivitiesofnanometerTiO2arealsoevaluatedbydegradationofthecrystalvioletsolution.ExperimentalresultsindicatethatthesynergisticactionofH2O2andultrasonicwavegreatlyenhancesphoto-catalyticreactionofTiO2.
简介:BasedonthetechniqueforpreparingLaCl3viadirectpyrolysisofrareearthchloridesolution,ajetpyrolysisreactorwasdesignedandtheintra-reactortemperatureandchemicalreactionswerenumericallysimulatedusingcomputationalfluiddynamics(CFD)technique.Theresultsshowthattheflowratevariationatthefuelinletdoesnotlargelyaffectthetemperatureinthereactor,whiletheincreaseinexternalpressureatthematerialinletrapidlydecreasestheaveragetemperature,Venturitemperature,andoutlettemperature.TheCH4andO2insidethereactorarecombustedcompletely,andwhenthematerialinletpressureis\90Pa,theLaCl3isfullypyrogenated.ThecontentsofCO2,La2O3,andHClfluctuateneartheVenturitubeandfinallystabilize.La2O3contentattheoutletisinatop-to-bottomgradient.
简介:Thecorrosionbehaviorandanti-corrosionmechanismoftheZn-Ni-Al2O3compositecoatingwereinvestigatedbySEM,EDSandXPS.TheresultsindicatethatthecorrosiontypeoftheZn-Ni-Al2O3coatingsinneutral5wt.%NaClsolutionisuniformcorrosion.ThepresenceofcompactanduniformlydispersednanoaluminaparticlessubstantiallyinhibitsthecorrosionofZn-Ni-Al2O3compositecoatings.Intheinitialcorrosionstage,thecorrosiveproductsofZn-NimatrixformacompactZnCl2·4Zn(OH)2layer.Withthedevelopmentofcorrosion,somenanoaluminaparticlesareembeddedandformaNienrichmentlayer.InNienrichmentlayer,NipresentsasNiandNiO.
简介:Fe2O3和ZnO的粉末混合物是在一家高精力的行星的球工厂的milled综合ZnFe2O4和X光检查粉末diffractometry被用来获得阶段,雏晶尺寸和Fe2O3和ZnFe2O4的microstrain的相对内容。Fe2O3的格子常数被房间精炼方法获得。macrokinetics和事的结构进化被学习,结果证明ZnFe2O4的mechanochemical合成的动力学过程适合Avrami-Erofe'ev模型并且被成核生长机制,和结构的macrokinetics理论在燃烧合成研究控制区域能被用来也描述运动过程。
简介:TheeffectofyttriaonthesolidreactionmechanismofaCaHPO4·2H2O+CaCO3systematdifferenttemperatureswasexperimentallystud-ied.Thesampleswithandwithoutyttriaweresubjectedtothermogravimetric/differentialscanningcalorimetrymeasurement.ThesampleswereheattreatedatthetemperaturescorrespondingtothepeaksontheDSCspectra,andtheresultedphasecompositionswereidentifiedbyX-raydiffraction.Thetransformationmechanismwasdeducedbycomparingthephasesobtainedatdifferenttemperatures.Theresultsshowthatthetransformationsatbelow1073Karenotaffectedbyyttria,butallthoseatabove1073Karecompletelyaltered.Theformationtem-peratureofhydroxyapatitedecreasesby134K,andthedecompositiontemperatureincreasesby38K.ThepolymorphoustransformationofCa3(PO4)2fromβphasetoαphaseincreasesby47K.Thethermodynamicpropertiesofthetransformationsatabove1073Karealsomodi-fiedbytheadditionofyttria;thatis,theendothermalpeaksaresubstitutedbyexothermalpeaks.
简介:ThermodynamicmodelsofcalculatingmassactionconcentrationsforstructuralunitsorioncouplesinRbCl-H2ObinaryandRbCl-RbNO3-H2Oternarystrongelectrolyteaqueoussolutionsweredevelopedbasedontheionandmoleculecoexistencetheoryat298.15K.Atransformationcoefficientisneededtocomparethecalculatedmassactionconcentrationandthereportedactivitybecausetheyareobtainedatdifferentstandardstatesandconcentrationunits.TheresultsshowthatthetransformationcoefficientsbetweenthecalculatedmassactionconcentrationsandthereportedactivitiesofthesamestructuralunitsorioncouplesinRbCl-H2ObinaryandRbCl-RbNO3-H2Oternarystrongelectrolyteaqueoussolutionschangeinaverynarrowrange.ThetransformedmassactionconcentrationsofstructuralunitsorioncouplesinRbCl-H2Obinarysystemareingoodagreementwiththereportedactivities.ThetransformedmassactionconcentrationsofRbClandRbNO3inRbCl-RbNO3-H2Oternarysolutionarealsoingoodagreementwiththereportedactivities,aRbCland3RbNOa,withdifferenttotalionicstrengthsas0.01,0.05,0.1,0.5,1.0,1.5,2.0,3.0and3.5mol/kg,respectively.AllthoseresultsmeanthedevelopedthermodynamicmodelofstrongelectrolyteaqueoussolutionscanreflectstructuralcharacteristicsofRbCl-H2ObinaryandRbCl-RbNO3-H2Oternarystrongelectrolyteaqueoussolutionsandthemassactionconcentrationalsostrictlyfollowsthemassactionlaw.
简介:利用高频辅助激光熔覆技术在镍基合金上制备Al2O3-13%TiO2(质量分数)陶瓷涂层。采用SEM、XRD和EDS等方法分析陶瓷涂层的微观结构和陶瓷层与粘结层之间的结合界面。结果表明:陶瓷层出现了完全熔化区和液相烧结区双层结构,其中,完全熔化区颗粒充分烧结长大,而液相烧结区则出现了三维网状结构,该三维网状结构由熔化的TiO2相包裹Al2O3颗粒形成。通过激光熔覆作用下的粉末熔化和扁平化行为解释双层结构形成机理。同时,在陶瓷层与粘结层的结合界面上发现具有尖晶石结构的NiAl2O4和针状结构的Cr2O3,证明在激光熔覆过程中发生的化学反应可以有效增加陶瓷层与粘结层的结合强度。
简介:多层的Nb2O5部nanoporous电影被控制阳极化过程成功地在包含4的乙烯乙二醇在Nb表面上综合?vol%HF并且2?vol%H2O2电解质。nanoporous电影被地排放扫描详细描绘电子显微镜学(FESEM),传播电子显微镜学(TEM),和X光检查衍射(XRD)。Nb2O5部nanoporous电影与~的方面墙厚度有多层的形态学5?nm,有~的一条直径的不规则的毛孔25?nm,并且一段多达7.39?m,取决于阳极化时间。为多层的Nb的机制<潜水艇class=“a-plus-plus”>2O<潜水艇class=“a-plus-plus”>5nanoporous形成也被讨论。这些nanoporous材料能在太阳能电池,煤气的传感器,催化剂,光过滤器,和电容器的地里是很有用的。
简介:ThispaperintroducesabrazingprocessbetweenAl_2O_3ceramicandInvaralloy.Al_2O_3canbebrazedwithInvareffectively.TheinterfacialstructureofAl_2O_3/Invarjointcanbeexpressedas:Invar/Ag(s,s)+Cu(s,s)+Fe_2Ti(zoneⅠ)/Ag(s,s)+Cu(s,s)+Fe_2Ti+NiTi+Cu_3Ti(zoneⅡ)/Ag(s,s)+Cu(s,s)+Cu_2Ti+Al(s,s)+TiC+TiO(zoneⅢ)/Al_2O_3.Themaximumshearstrengthof139MPawasmeasuredforas-brazedAl_2O_3/Invarjointbrazedat850℃for25minor900℃for15min.
简介:ScanningElectronMicroscopyStudiesofYBa_2Cu_3O_(7-δ)SuperconductorsShaWei(沙维)(DepartmentofCivilEngineering,TheQueen′sUniversit...
简介:ThelongafterglowSrAl2O4:Dy,Euphosphorisliabletohydrolyzeinwaterwithdeteriorationoftheluminescentproperty.SrAl2O4:Dy,Euphosphorswerethereforeheatedat60-90℃inTEOSsoltoformasurfacegelandthenheat-treatedat400℃toobtainSiO2coatedphosphors.ObservationbyTransmissionElectronMicroscope(TEM)andX-rayphotoelectronspectroscopy(XPS)showsthatathinsilicafilmformsonthesurfaceofthephosphors.Thecoatingprocedurecanbeillustratedbyafour-stepprocessandthetransparentsilicafilmcansuppressthehydrolysisprocess,sothattheluminescentpropertiesofthephosphorsareunimpairedorevenbetter.
简介:HotcompressionbehaviorofTiC–Al2O3/AlcompositeswasstudiedusingtheGleeble-1500systematatemperaturerangeof300–550°Candatstrainraterangeof0.01–10.00s-1.TheassociatedstructuralchangeswerestudiedbyTEMobservations.Theresultsshowthatstressleveldecreaseswithdeformationtemperatureincreasingandstrainratedecreasing,whichcanberepresentedbyaZener–Hollomonparameterinanexponent-typeequationwithhotdeformationactivationenergyQof172.56kJ·mol-1.Dynamicrecoveryoccurseasilywhenstrainratesarelessthan10.00s-1.Dynamicrecrystallizationcanoccuratstrainrateof10.00s-1.