简介:Wehaveinvestigatedthelow-lyingcollectivestatesandelectromagnetictransitionsin94Mowithintheframeworkoftheinteractingbosonmodel.Theinfluenceofmodelparametersontheenergylevelsandelectromagneticpropertieshasbeeninvestigated.Theanalysisoftheobtainedresultsandtheparametervaluespredictthatthe23+stateisthelowestmixedsymmetrystatewithpureF=Fmax-1inthisnucleus.Thecalculatedresultspredicatethatthe25+(two-Q-phonon)mixedsymmetrystateisclosedtotheJ=2+at2.870MeVintheexperimentaldata,andthe2.965MeVstateisthelowestmixedsymmetrywithJ=3+.
简介:NanocrystallineNi-Mo-Fealloydepositswereobtainedbyelectrodeposition.ThestructuresofthealloydepositswereanalyzedbyX-raydiffraction(XRD)andX-rayphotoelectronspectroscopy(XPS).TheXRDresultsofnanocrystallineNi-Mo-Fealloydepositshowthatmanydiffractionlinesdisappear,andthatthereisonlyonediffractionpeakat44.0°.TheXPSresultsofnanocrystallineNi-Mo-Fealloydepositsindicatethatthenickel,molybdenumandironofthedepositsexistinmetallicstate,andthatthebindingenergyofthealloyedelementsincreasestosomeextent.ThenanocrystallineNi-Mo-FealloydepositelectrodemayofferbetterelectrocatalyticactivitythanthepolycrystallinenickeleletrodeandthenanocrystallineNi-Moalloyelectrode.TheelectrochemicalimpedancespectrafromthenanocrystallineNi-Mo-Fealloyelectrodeindicatethathydrogenevolutionin30%(m/m)KOHatloweroverpotentialisinaccordancewiththeVolmer-Tafelmechanism,butwiththeVolmer-Heyrovskymechanismathigheroverpotential.
简介:通过溶液培养试验,研究外源添加Mo对2种价态砷(As(Ⅲ)和As(Ⅴ))胁迫下水稻吸收积累Mo和As的影响。结果表明,这2种价态的As对水稻生长均有抑制作用,As(Ⅲ)比As(Ⅴ)对水稻毒害更明显,添加Mo可缓解As对水稻的毒害。As添加可影响水稻根系和茎叶对Mo的吸收积累,但是不同价态As对Mo积累量的影响不一致。同时,Mo的添加也可以显著地降低水稻根系和茎叶对2个价态As的吸收积累。在100μmol·L^-1As(Ⅲ)处理下,添加0.1和0.5mg·L^-1的Mo可导致水稻根系As积累量分别比对照处理降低38.8%和52.8%,茎叶As积累量分别降低5.1%和10.6%;当As(V)浓度为100μmol·L^-1时,添加0.1和0.5mg·L^-1的Mo可导致水稻根系As积累量分别比对照处理降低15.4%和62.4%,茎叶As积累量分别降低11.9%和23.7%。Mo的添加还能显著地降低2种价态As在水稻根系和茎叶中的富集系数。因此,通过施用适量的Mo肥可以用来防治农田As污染,降低As对人体健康的危害。
简介:ThemicrostructuresandVickershardnessatroomtemperatureofarc-meltingprocessedintermetallicsofMo5Si3-MoSi2hypoeutecticalloyandhypereutecticalloyannealedat1200℃fordifferenttimewereinvestigated.LamellarstructureconsistedofMo5Si3(D8m)phaseandMoSi2(C11b)phasewasobservedinallthealloys.ForMo5Si3-MoSi2hypoeutecticalloy,thelamellarstructurewasfoundonlyafterannealinganddevelopedwellwithfinespacingontheorderofhundrednanometersafterannealingat1200℃for48h.Butwhentheannealingtimewasupto96h,thewell-developedlamellarstructurewasdestroyed.ForMo5Si3-MoSi2hypereutecticalloy,thelamellarstructurewasfoundbothbeforeandafterannealing.Howeverthevolumefractionandspacingofthelamellarstructuredidnotchangesignificantlybeforeandafterannealing.Theeffectsoftheformation,developmentanddestructionoflamellarstructureonVickershardnessofalloyswerealsoinvestigated.WhenMo5Si3-MoSi2hypoeutecticalloyannealedat1200℃for48h,theVickershardnesswasimprovedabout19%comparedwiththatwithoutannealingandformationoflamellarstructure.ThehighestVickershardnessofMo5Si3-MoSi2hypereutecticwasincreasingabout18%whenannealingat1200℃for48h.
简介:【 摘要 】 钛合金与铝合金是当下金属材料中运用较多的两种材料,且应用范围较为广泛。碳合金与铝合金一般情况下是分类进行的使用,但特殊情况下两种材料会共同使用,这也就对金属焊接工作提出了更高的要求。文章就钛合金与铝合金异种金属的焊接技术进行分析,以促进异种焊接技术的应用与发展。
简介:晶体结构和加氢行为(La_(1-x)Mg_x)_3Al(x=0.1,0.2,0.3,和0.4)合金被调查。这被发现有x=的合金0.1La和第0.2consi(Mg,艾尔),La,和一个新奇阶段。新奇阶段作为La_2Al被决定。当Mg满足增加,La_2Al的数量减少,这被显示出。当x增加到0.3时,onlyLa(Mg,艾尔)并且La_2Al的小数量存在。当x是0.4时,La_2Al阶段消失,合金包含两La(Mg,艾尔)并且La(艾尔,Mg)_2洗阶段。(La_(0.9)Mg_(0.1))_3Al并且(La_(0.7)Mg_(0.3))_3Al合金能被氢的吸收在473K分解成LaH_3,MgH_2,和La_2Al_5。
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简介:ThemeasurementsoftemperaturedependenceofthemagneticsusceptibilityofLa1-xSrxCoO3perovskiteoxidesatdifferentSrdoping(0≤x≤0.5)andannealingtemperaturewerepresented.Forthesamplewithx=0.1,ashoulderwasobservedaround150K,andapeakwhichisonefeatureofspinglassappearedaround50Kinthecurveofsusceptibilityversustemperature.Thehigh-temperature(250~420K)susceptibilityfitswellwithCurie-Weisslawforallsamples.WeissconstantandeffectivemagneticmomentweredeterminedandtheirvariationswithSrdopingandoxygenannealingconditionwereobtained.TheWeissconstantincreasesmonotonouslywithSrcontentforx>0.2.Thevaluesofeffectivemomentswereinterpretedwiththespinstateofcobaltions.Studiesonthesusceptibilitiesofthesampleswithx=0.2underdifferentpreparationtemperaturesandannealingtemperaturesshowthattherisingofsinteringtemperatureandannealingtemperaturewillincreasethepara-ferromagnetictransitiontemperature,andreducetheeffectivemomenttonormalvalue.OurresultshowsthatbothCo3+andCo4+ionsshouldbeinISstateafterannealingandtheoxygenannealingcausesthetransitionofCo3+spinstatefromHStoIS.