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107 个结果
  • 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.

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  • 简介:Nd_2Zr_2O_7isbeingexploredasanalternatethermalbarriercoating(TBC)materialforoperatingabove1300°C,andgreatefforthasbeenmadetoenlargeitsthermalexpansioncoefficient(TEC)andimproveitstoughness.Inthisstudy,Sc_2O_3wasdopedtoNd_2Zr_2O_7.Thephasestructure,TECsandtoughnessof((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075,0.1)compoundswereinvestigated.((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075)exhibitedpyrochlorestructure,while((Nd_(0.9)Sc_(0.1)))_2Zr_2O_7consistedofpyrochloreandfluoritephases.WiththeincreaseoftheSc_2O_3content,theorderingdegreeofthepyrochloreinthecompoundsdecreased.In((Nd_(1-x)Scx))_2Zr_2O_7series,((Nd_(0.925)Sc_(0.075)))_2Zr_2O_7exhibitedthelargestTEC,whilethetoughnessofthecompoundsincreasedwithincreasingtheSc_2O_3content.Therelatedmechanismswerediscussedbasedonthecrystalstructureanalysis.ConsideringtheTECandtoughness,10mol%Sc_2O_3wassuggestedastheoptimaldopingcontentforNd_2Zr_2O_7ceramic.

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  • 简介:NanocrystallineNi1?有0的xZnxFe2O4铁酸盐?x?1被一个水花一起沉淀方法成功地准备。微观结构被使用XRD和TEM调查。磁性与颤动被测量在房间温度的样品磁强计(VSM)。结果证明谷物nanocrystalline缩放Ni1?在600点锻烧的xZnxFe2O4铁酸盐?祥獥Δ

  • 标签: 锌铁氧体 共沉淀法 微结构 性能 比饱和磁化强度 离子含量
  • 简介:GB12021.3—2010《房间空气调节器能效限定值及能效等级》已于2010年2月26日发布,并于2010年6月1日正式实施。该标准与GB12021.3—2004相比,主要变化如下:

  • 标签: 房间空气调节器 能效等级 限定值
  • 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.

  • 标签: Cd1-xZnxS/K2La2Ti3O10 COMPOSITES PHOTOCATALYSIS hydrogen evolution WATER
  • 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。

  • 标签: 溶胶-凝胶法 纳米晶体 等量掺杂 磁电阻