简介：TheeffectofLaelementonthemechanicalpropertiesandconstitutionnearbygrainboundaryinaCo-basesuperalloyCo-22Ni-22Cr-14kduring760℃ageinghasbeeninvestigatedbyAESandmaterialtesting.ResultsshowthatelementLacanbeinastateofsolidsolutionandsegregatesmainlyatthevicinityofgrainboundaries.ThepriorsegregationofLaatomscanaffectsegregationbehaviourofotherelements,sothatexertsinfluenceonmicrostructureofthealloy,ParticularlyincreasingofLacontentcandecreasePconcentrationatthevicinityofgrainboundariesbutnotdecreaseSconcentration.StogetherwithLaproducecosegregationeffect.ThecontentofLahasnoobviouseffectonhightemperaturestrength.WhenthecontentofLacomesupto0.02wt-％,itcanobviouslyimprovethehightemperatureductility.

简介：La9.33Si6O26氧离子导体被稳固的州的reactionmethod.Its综合结构被单个水晶的X光检查衍射分析在结果显示出的roomtemperature.The决定那La9.33Si6O26氧化物让磷灰石组织，空间groupP6_3/m.AC阻抗大小显示了在氮的氧化物sintered在空中比那些sintered有高得多的电导率。传导性上的谷物边界的效果被讨论。

简介：TherepresentativesampleLa0.58Dy0.09Ca0.33MnO3ofDydopedLa0.67Ca0.33MnO3rare-earthmanganiteswasinvestigated.ThemostimportanteffectofDydopingistointroducethemagnetoimpurityandformthespinclusterswhichinducedramaticallylargeCMRinLa0.58Dy0.09Ca0.33MnO3.Thefittingresultsoffield-inducedresistivitydecreasetotheBrillouinfunctionindicatethattheCMRiscausedbythespindependenthoppingbetweenspinclusters.Itisthemagneticfieldthatreducesthesizeofspinclustersandinducesafield-inducedirreversibleCMRbehaviour.

简介：InvestigationhasbeencarriedouttofindtheeffectsofNdsubstitutionandCuadditiononthehydrogenstoragepropertiesofAB5-typealloywithamulticomponentLa0.6M0.4Ni4.8Mn0.2(M=Y,Nd)system.La0.6Y0.4Ni4.8Mn0.2,whichwasusedinanair-conditioningsystem,showedpoorhysteresisandslopingcharacteristics,whichledtoadecreaseconcerningthecoefficientofperformanceofthesystem.BythesubstitutionofNdforY,thehydrogenstoragecapacityincreased,andtheplateaupressuredecreasedalittle,butthehydrogenabsorptionkineticsdecreaseddramatically.CuadditioncaneffectivelyimprovethekineticsofhydrideformationwithoutchangingthehydrogenstoragecapacityofLa0.6Nd0.4Ni4.8Mn0.2.IthasbeenfoundthatLa0.6Nd0.4Ni4.8Mn0.2Cu0.1alloyshowedgoodhydrogenstoragecharacteristicsformetalhydrideair-conditioningsystem.Theresultsshowedthat,foreachcomponentofLa0.6Mo.4Ni4.8Mn0.2,theeffectivehydrogenstoragecapacityincreasedwithdecreaseoftheunitcellparameterc/aandthehydrogenabsorptionplateaupressureincreasedwithdecreaseoftheparametera.

简介：三新奇Ba_5RNiNb_9O_(30)(R=La，Nd和Sm)陶艺在BaO-R_2O_3-NiO-Nb_2O_5系统被准备并且描绘。所有三混合物areparaelectjicphasesadopting。在房间温度的充满的四角形的钨铜(TB)结构。在1MHz，Ba_5RNiNb_9O_(30)陶艺有高电介质在范围193-245.3，在范围0.0059-0.0087的低绝缘的损失，和在范围的绝缘的常数(tau_e)的温度系数的常数-1140-1310X10~(-6)中心点degC。他们绝缘的常数的温度系数显著地Ba_5RNiNb_9O_(30)与那些相比被减少(R=La，Nd，Sm)陶艺。

简介：用溶胶-凝胶法制备了系列掺杂（La0.8Ln0.2）2/3Ca1/3MnO3（Ln=La，Ce，Pr，Nd，Sm，Eu）纳米级晶体。对比在La被其它镧系元素部分替代后，引起的A位离子平均半径的改变和磁矩变化对电输运及磁阻性能的影响，实验分析表明，各个样品在同样大小磁场下的磁电阻存在较大的差别，样品的磁电阻随原子序数的增加而明显变大，由镧系收缩引起晶格畸变所产生的本征磁电阻占主导地位，随着外加磁场的增加，不同掺杂样品间的峰值电阻差异被弱化；各掺杂样品间的转变温度差与掺杂离子半径差和磁矩差密切相关，且离子半径的差异对转变温度的改变贡献更大。

简介：以La（NO3）3·nH2O、Pr（NO3）3·6H2O、Ni（NO3）3·6H2O为原料，丙氨酸为分散剂，采用低温燃烧法合成了（x=0．1～0．9）系列钙钛矿型复合氧化物。用TGDSC、XRD、TPR、SEM等表征手段对样品进行表征。结果表明，La0.5Pr0.5NiO3在650℃开始形成稳定的钙钛矿结构，焙烧800℃时，表面晶粒均匀；随着Pr的取代度增大，Pr离子未能完全进入LaNiO3晶格中A位，以氧化物的形式存在于钙钛矿晶体表面，同时La1-xPrxNiO3表面存在两种不同活性的氧物种，缺陷氧结构数量随着取代度的增大而增大。

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简介：稀土磷酸盐由于其优异的物理化学性能而日益受到重视，其中RePO4（Re--Ce，La）纳米粉体的制备是影响其性能的主要因素。综述了LaPO4和CePO4粉体的制备方法及其最近研究进展，详细介绍了化学沉淀法、水热法、固相法、溶胶一凝胶法以及微乳液法．并对其优缺点进行了评述，提出了通过微波辐射来合成纳米RePO4的方法。

简介：(1-x)La_(0.67)Ca_(0.33)MnO_3/Cr_2O_3(LCMO)+xCr_2O_3composites被一个新液相方法综合。XRD和SEM大小表明在LCMO结构和LCMO的晶格常数可溶的很少Cr_2O_3几乎没变化，当大多数Cr_2O_3在谷物边界或在LCMO谷物的表面上是分布式的时。Inresistivity对温度大小，金属--绝缘体转变被观察什么时候x<0.20。抵抗力增加和金属--绝缘体转变温度与Cr_2O_3的增加的内容减少。一个随机的电阻器网络(KRN)模型被使用，到模仿混合样品的运输性质。模拟结果同意试验性的观察。结果证明方法为理解maganite的composites的电子运输是合理的。

简介：采用浸渍法制备了不同La掺杂量的Ni—SiO2催化剂，研究了La掺杂量对Ni—SiO2催化剂的Ni活性金属粒径、还原性能、甲烷催化裂解寿命以及反应后生成碳纤维的影响。结果表明：La、Ni物质的量比由0增长至0．3时，Ni-SiO2催化剂的寿命显著提高，而当La、Ni物质的量比由0．3增长至0．6时，催化剂寿命在一定程度上略有降低；La、Ni物质的量比由0增长至0．6时，还原后催化剂Ni金属的平均粒径从26．43nm不断降低至10．57nm。不同La掺杂量Ni—SiO2催化剂甲烷催化裂解过程中Ni金属平均粒径变化趋势明显不同，n（La）：n（Ni）=0的Ni—SiO2催化剂随反应进行Ni金属平均粒径不断降低，而n（La）：n（Ni）=0．3的Ni—SiO2催化剂随反应进行Ni金属平均粒径则不断升高。碳纤维形态受掺La掺杂量影响较大，随La、Ni物质的量比由0增长至0．3，反应过程中生成的碳纤维管径变粗，而随La、Ni物质的量比由0．3增长至0．6，碳纤维变短。

简介：Anewroutetosynthesizenanosizedcrystallineof(La0.67–XGdX)Sr0.33MnO3(X=0.05,0.10,0.15,0.20)perovskite-typecomplexoxidesatcalcinationtemperatureof600-1000°Cusingtheamorphousmolecularalloyasprecursorswasreported.Theprecursorcouldbecompletelydecomposedintocomplexoxideattemperaturebelow500°CaccordingtotheTGAandDTAresults.XRDdemonstratesthatthedecomposedspeciesiscomposedofperovskite-typestructureatcalcinationtemperatureof600°Cfor2h.Theparticlesizethatdependsonthecalcinationtemperatureoftheprecursorisinarangeof30-120nmasdeterminedbytransmissionelectronmicroscopy(TEM).Thismethodiseffectiveandcanbeeasilyquantitativelycontrolledtosynthesizenanosizedperovskite-typecomplexoxides.Themagneticpropertiesof(La0.67–XGdX)Sr0.33MnO3nanocrystallinewerepreliminarystudied.

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简介：Anitrate-citratecombustionroutetosynthesizeLa0.9Sr0.1Ga0.8Mg0.2O3-δpowderforsolidoxidefuelcellapplicationwaspresented.Thisrouteisbasedonthegellingofnitratesolutionsbytheadditionofcitricacidandammoniumhydroxide,followedbyanintensecombustionprocessduetoanexothermicredoxreactionbetweennitrateandcitrateions.TheoptimumtechnicalparametersarethatthepHvalueis5,andthemolarratioofcitricacidtothetotalmetallicionis1.5:1.X-raydiffractioncharacterizationofcalcinedgelshowsthatpurephasewassynthesizedaftercalcinationat1400℃for10h,andtheTEMresultshowsthecalcinedpowderwithaverageparticlesizeisabout150nm.Thegrainresistancecontributestothetotalresistanceofsinteredpelletbelow500℃.Theconductivityofthesinteredpellentat800℃was0.07S-1.cm-1higherthantheconductivityofYSZ(0.05S-1.cm-1at800℃)

简介：ThetransportpropertiesintheLa2/3(Ca1-xSrx)1/3MnO3(x=0,1/3,2/3)filmspreparedusingtheRFmagnetronsputteringmethodwereinvestigated.TheeffectoftheCa,Srdouble-dopingattheApositionintheLa2/3A1/3MnO3onthestructureofthetargetsandtransportofthefilmshasbeenstudied.Withtheincreaseofx,thestructuresofthetargetstransformfromtherhombohedralphasetothecubicphase;themetal-insulatorphasetransitiontemperature(Tp)ofthefilmsincreases;andthecorrespondingpeakresistivitydecreases.Allthephenomenacanbequalitativelyexplainedbythelatticeeffect.

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简介：Inordertorealizetheco-firingwithAg/Pdelectrodesinmultilayerdevices,Pb(Zn1/3Nb2/3)1-,-yZrxTiyO3(0.25＜x＜0.35,0.25＜y＜0.35)piezoelectricceramics(hereafterdesignatedPZN-PZT)modifiedbyLa2O3hasbeenpreparedbyconventionaltechniquewithsinteringtemperaturefrom1100℃to1140℃.X-raydiffractionpatternsdemonstratedthatpureperovskitephasewasobtained.Secondaryelectronimage(SEI)showedthatcrystallinegrainsinceramicswerewellgrown.d33ofmanufacturedsamplewasashighas560×10-12C/N.kpwasabout0.61andtgδabout30×10-3.TheexistenceofliquidphaseexaminedbyelectrondiffractioninPZN-PZTsampleisbeneficialtosinteringoftheceramic.

简介：AseriesofCd1-xZnxS/K2La2Ti3O10compositesweresynthesizedviaasimpleco-precipitationmethod.ThepreparedsampleswerecharacterizedbyX-raydiffraction（XRD）,scanningelectronmicroscopy（SEM）,X-rayenergydispersivespectroscopy（EDX）,ultraviolet-visiblediffusereflection（UV-Vis）,X-rayphotoelectronspectroscopy（XPS）andphotoluminescence（PL）measurements.ThecompositestructuresconsistedofCd1-xZnxSnanoparticlesevenlydistributedonthesurfaceofK2La2Ti3O10.TheabsorptionedgeofK2La2Ti3O10shiftedtothevisiblelightregionuponintroductionoftheCd1-xZnxSnanoparticles.Thephotocatalyticactivitiesofthecatalystswereevaluatedbyhydrogenproductionundervisiblelightirradiation.ThepreparedCd0.8Zn0.2S（30wt%）/K2La2Ti3O10exhibitedhigherphotocatalyticactivity,evolving6.92mmol/gH2undervisiblelightirradiationfor3h.ThepromotedphotocatalyticactivityofthecompositeswasattributedtothesynergisticeffectbetweenCd1-xZnxSandK2La2Ti3O10,whichresultedinenhancedseparationofphotogeneratedelectronsandholes.