学科分类
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  • 简介:WehavestudiedtheMossbauereffectofYBa2Cu2.88Fe0.12O7-xsuperconductiveoxidefrom78to273K.TwominimaofrecoillessfractionandDebyetemperaturewerefoundnear110Kand220K.Itmeansthatlatticesofteninghappenednearthesetwotemperatures.Wealsoobservedminimaofisomershiftnear110Kandquadrupolesplittingincreasewhentemperatureislowerthan110K.Wesuggestthatlatticesofteningwouldleadtothedisplacementofoxygenatoms.Thismayberelativetosuperconductivetransition.

  • 标签: Y-Ba-Cu-Fe-O superconductor MOSSBAUER effect lattice softening
  • 简介:EnthalpyofReactionsinY-Ba-Cu-OSystemShaWei沙维(Departmentof.MaterialsScienceandMetallurgy,UniversityofCambridge.U.K.)Received17...

  • 标签: THERMODYNAMIC PROPERTIES SUPERCONDUCTORS PHASE TRANSFORMATION
  • 简介:МИРB2000ГОДУ参考译文2000年的世界美国环境保护委员会和国务院的专门委员会对2000年地球文明的发展作了预测。在假设不发生任何社会经济或工艺革命,保持现有工业发展的性质的条件下,该委员会得出了一些非常悲观的结论。下面介绍其中几项结论。地球...

  • 标签: 现有工业 社会经济 增长量 国民总收入 工业三废 幅射
  • 简介:1.IntroductionSofarthemicrostructureandcoercivityofSm(Co,Cu,Fe,Zr)7.4alloyhavebeenstudiedindetailbyvariousauthors.TheeffectofZr-richlaminarphasestructureonthehighcoecivityofalloyismoreattractive.Thechangesofmagnetic

  • 标签: HVEM OBSERVATION COERCIVITY ND-FE-B alloy
  • 简介:1.IntroductionLightrareearthadditioncanremarkablyenhancetheservicelifeofFe-Cr-Alalloyforelectricalheatingelement,butitscontentinthealloymustbecontrolledbelowthelevelof0.1wt-%.Whenthecontentexceedsthat,theperformance

  • 标签: YTTRIUM ADDITION FE-CR-AL ALLOY EMBRITTLEMENT
  • 简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.

  • 标签: ALUMINA active BRAZING INTERFACIAL reaction joint
  • 简介:Wehaveshownthat,incontrasttotheresultsintheliterature,theBraggpeakintensityofNi80Fe20/Cusuperlatticesisenhancedattheincidentx-rayenergyslightlyhigherthantheabsorptionedgeoftheheavierelement(Cu).TheatomicdensityatNi80Fe20/Cuinterfacewasanalysedbythediffractionanomalousfinestructuretechnologywiththeincidentangleofx-rayfixedatthefirstBraggpeak.OurresultsdemonstratetheepitaxygrowthofNi80Fe20/Cusuperlattices.Uponannealing,theepitaxityofNi80Fe20/Cumultilayersbecomespoorbutthelocalcrystallinityineachlayerisimproved.

  • 标签: X射线分析 微观结构 原子分布 Ni80Fe20/Cu超晶格 晶体生长
  • 简介:Inthisletter,Fe2O3UFP(UltrafineParticles)hydrosolandorganosolwithhighthirdorderopticalnonlinearsusceptibility(3)havebeenreportedforthefirsttime.ThesurfacialmodificationofFe2O3UFPwithdodecylbenzenesulfonateions(DBS)canenhancethenonlinearopticalresponsethroughinterfacialconfinementofelectronmotion.Theinvolvedmechanismisdiscussed.

  • 标签: CONFINEMENT INTERFACIAL SUSCEPTIBILITY ULTRAFINE hinder coated