简介:WehavestudiedtheMossbauereffectofYBa2Cu2.88Fe0.12O7-xsuperconductiveoxidefrom78to273K.TwominimaofrecoillessfractionandDebyetemperaturewerefoundnear110Kand220K.Itmeansthatlatticesofteninghappenednearthesetwotemperatures.Wealsoobservedminimaofisomershiftnear110Kandquadrupolesplittingincreasewhentemperatureislowerthan110K.Wesuggestthatlatticesofteningwouldleadtothedisplacementofoxygenatoms.Thismayberelativetosuperconductivetransition.
简介:在为光玻璃BK7的擦伤过程的有弹性塑料的转变政体和易碎可锻的转变政体被分析基于赫兹波方程和被魏建议的压力比率理论。为有变量被有限元素模拟的ABAQUS软件基于精力破裂理论模仿的砂砾间隔距离的光玻璃BK7的交往的擦伤进程。为光玻璃BK7的双砂砾交往擦伤测试在DMG超声的70-5上被执行线性,由哪个有限元素模拟的可靠性被验证。细工品的表面形态学被扫描电子显微镜学(SEM)分析,它证明沟的宽度随擦伤深度和砂砾间隔距离的增加显然增加了。沟的宽度的结果与模拟结果一致。表面下的损坏层被蚀刻的HF酸的方法分析,它证明有交叉的裂缝的一个区域。抓的力量被KISTLER的threedimensional测力计测量,它证明第二抓的力量随抓深度和砂砾间隔距离的增加增加了。在第二处擦伤的力量在第一次是比那小的,它与Griffith破裂理论一致。
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:Thepresentstudyisconcernedwiththeeffectoffillermetalssuchasausteniticstainlesssteel,ferriticstainlesssteelandduplexstainlesssteelontensileandimpactpropertiesoftheferriticstainlesssteelconformingtoAISI409Mgrade.Rolledplatesof4mmthicknesswereusedasthebasematerialforpreparingsinglepassbuttweldedjoints.Tensileandimpactproperties,microhardness,microstructureandfracturesurfacemorphologyofthejointsfabricatedbyausteniticstainlesssteel,ferriticstainlesssteelandduplexstainlesssteelfillermetalswereevaluatedandtheresultswerereported.Fromthisinvestigation,itisfoundthatthejointsfabricatedbyduplexstainlesssteelfillermetalshowedhighertensilestrengthandhardnesscomparedtothejointsfabricatedbyausteniticandferriticstainlesssteelfillermetals.Jointsfabricatedbyausteniticstainlesssteelfillermetalexhibitedhigherductilityandimpacttoughnesscomparedwiththejointsfabricatedbyferriticstainlesssteelandduplexstainlesssteelfillermetals.