简介：WestudiedthespatialevolutionoftheFe-Niplasmageneratedbythefundamental(1064nm)andsecond(532nm)harmonicsofaQ-switchedNd:YAGlaser.Theexperimentallyobservedlineprofilesoftheneutraliron(FeI)havebeenusedtoextracttheplasmatemperature(Te)usingtheBoltzmannplotmethod,whereastheelectronnumberdensity(Ne)hasbeendeter-minedfromtheStarkbroadening.Inaddition,westudiedthespatialbehaviorofTeandNewiththevariationoflaserenergyforironplasmabyplacingthetargetmaterial(iron-nickelalloy)inairatatmosphericpressureforbothmodesoftheNd:YAGlaser.

简介：TheballmillingofFe-24MnandFe-24Mn-6Simixedpowdershasbeenperformedbythehighenergyballmillingtechnique.ByemployingX-raydiffractionandMoessbauermeasurements.Theccmpositionevolutionduringthemillingprocesshasbeeninvestigated.TheresultsindicatetheformationofparamagneticFe-MnorFe-Mn-Sialloyswithametastablefccphaseasfinalproducts.whichimplythattheFeandMnproceedaco-diffusionmeenanismthroughthesurfaceoffragmentedpowders.Thethermalstabilityandcompositionevolutionoftheas-milledalloyswerediscussedcomparingwiththebulkalloy,.

简介：Themicroscopiceffectivechargesinmirrornuclei51Mnand51Feareinvestigatedwiththeparticle-vibrationcouplingmodelbasedontheself-consistentSkyrme-Hartree-Fockandcontinuumrandom-phase-approximationapproaches.Theisovectorpartsarepredictedtobearound0.15,andtheprotoneffectivechargesarearound1.25e,whichislessthantheempiricalvalueofeeffp=1.5e.Themicroscopiceffectivechargesinneutronrich51Mnareabout10%lessthanitsprotonrichmirror.TheseeffectivechargesarecombinedwiththeshellmodeltocalculatethereducedelectricquadrupoletransitionprobabilityB(E2)valuesin51Mnand51Fe.ItturnsoutthatthemicroscopiceffectivechargeshavewellreproducedtheB(E2)valuesanditsratiointheterminatingstates.

简介：TheatomicstructureofanovelrareearthcomplexconsistingofNdandthesulfur-containingligandpipdtc(C5H10NCS2^-)hasbeenstudiedwithextendedx-rayabsortpitonfinestructure(EXAFS)andx-raydiffractiontechniques.ThecomplexofformulaNd(pipdtc)4N(CH3)4crystallizaesinthemonoclinicspacegroupP21/nwiththefollowinglatticeparameters,a=22.685(2),b=20.332(2),c=17.1270(10)A,β=100.570(10)°.Z=8,thecalculateddensityis1.47g/cm^3,Anewderivativemethodisusedtoremovethepiost-edgeabsorptionbackgroundincludingthemultielectronexcitationeffect.TheEXAFSresultsdemonstratethatthereareabouteightSandfourOatomsaroundNdwiththeNd-Sbondlengthof2.916AandtheNd-Obondlengthof2.415A,respectively.Thisimpliesthatthepowderofthiscomplexisnotstableandiseasytooxidizeinair.Thepossiblechangeofstructurebeforeandafteroxidationisdiscussed.

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简介：本文采用溶胶-凝胶法，获得了铁掺杂的纳米TiO2样品，XRD和透射电镜测量表明在600℃以下焙烧时为锐钛矿，颗粒度在10nm以下，样品在1000℃下焙烧时，转变为金红石相，颖粒度增大。EXAPS和穆谱表明，铁的确掺杂到TiO2晶格内，表现为3价。铁的掺杂改变了纯的TiO2的性质，对于锐铁矿相的掺铁纳米TiO2，其紫外-可见反射光谱给出在481nm处出观了新的吸收峰，；对于以金红石相为主的掺铁纳米TiO2，其紫外-可见反射光谱在512nm处出现了新的吸收峰。

简介：通过水热法合成了骨架含铁的杂原子丝光沸石，采用XRD，FT－IR及TPR等表征技术确认铁进入了分子筛骨架。利用XAFS技术对分子筛中铁的精细结构和配位环境进行了表征和计算，近边吸收的Fe-K边前跃迁证实铁在分子筛骨架中位于四面体配位环境中，与邻近原子存在共价键作用；铁－氧配位键长为0.188-0.189nm.

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简介：TherearetwotpyesofphasetransformationsinFe-MnandFe-Mn-Sialloyswhenthetemperatureisdecreased,γ(fcc)→ε(hcp)martensitictransformation(MT)andparamagnetic-antiferromagnetictransition(AMT)ofγphase.Fromthethermodynamicpointofview,theformerusuallyappearsinaslightlyhighertemperaturerangethanthelatterbecauseifisgenerallyacceptedthatthemagnetictansitionhasasuppressingeffectonthethermallyinducedεmartensite(Satoetal.,1984.,BogachevandZvigintzeva,1976;Murakamietal.,1987:Yangetal.,1992)GartsteinandRobinkin(1979)eventhoughtthattheγ-εtransformationshouldbeterminatedbelowNeeltemperature(TN)duetothedecreaseoffreeenergyarisingfromtheAMTofγphase.However,someexperimentalresultshaeindicatedtheformationofεphasebelowT(LiandWayman,1994:Fujimori.1966).Inthepresentwert.thebehavorofγ-εtransformationbelowTNwasfurtherinvestigatedbyclectricalresistancemeasurements.

简介：给出了北京正负电子对撞机（BEPC）同步辐射新组装的3W1Wiggler束斑强度分布及光子束流的测量结果，并与理论计算作了比较，两者得出了一致的结果。

简介：本文利用XAFS方法研究机械合金化方法制备的Fe100-xCux(x=0,10,20,40,60,70,80,100,x为原子百分比）合金中Fe、Cu原子的局域环境结构随组成的变化。对于Fe100-xCux二元混合物，当x≥40时，Fe原子的近邻配位结构从bcc转变为fcc，但Cu原子的近邻结构保持其fcc不变；与之相反，当x≤20时，Fe原子的近邻配位保持bcc结构而Cu原子的近邻配位结构从fcc转变为bcc结构。XAFS结果还表明fcc结构的Fe100-xCux中Fe的无序因子σ（0．009A）比bcc结构的Fe100-xCux中的σ（0．081A）大得多；并且在同一机械合金化Fe100-xCux（x≥40）样品中Fe原子的σ（0．099A）比Cu原子的σ（0．089A）大。这表明机械合金化的Fe100-xCux样品中Fe和Cu原子可以有相同的局域结构环境但不是均匀的过饱和固溶体，而是fcc或bcc合金相同时存在Fe富集区和Cu富集区。

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简介：本文在分析了北京同步辐射室4B9B原束线低能分支的构造及弊病后，在不影响束线高能分支性能及总体机械结构的基础上提出了改进方案。文中不仅详细介绍了该设计方案，同时也介绍了97年4月份专用光开始前夕的调试工作及出光后束线的性能测试工作，测试结果完全符合设计要求。该束线在这次同步辐射专用光实验中充分发挥了改进后的优势，取得了令人满意的结果。

简介：Theγ-Fe2O3nanoparticlescoatedwithDBSandCTABwerepreparedbythemicroemulsionmethod.Thecoatedsamplesshowenhancednonlinearopticalpropertiescomparedwiththeirbulkcouterpart.The.Moessbauerspectraatroomtemperatureweremeasuredforthecoatedferricoxides.Themonolayersoftheorganicmoleculearefoundtohaveastrongchemicalbondwiththesurfaceatomsandthushaveasignificantinfluenceontheelectronstructureofparticlesurface.@1999ActaMetallurgicaInc.

简介：Thenanoparticlesγ-Fe2O3coatedwithsurfactants.DBS,STandCTAB.repsectively.weresynthesizedbymicroemulsionmethod.Thecoatedferricoxides.whichshowenhancednonlinearopticalpropertiescomparedwiththeirbulkcounterpart.wereprobedbyEXAFSinsolutionforms.Thex=-rayabsorptionspectraforFeKedgeweremeasuredatroomtemperaturebyhelpofsynchrotronradiationlightsource.Extendedx-rayabsorptionfinestructureanalysisshowsthatthecoatinglayersoforganicmoleculesinteractwithsurfaceatomsofnanopartices,theFe-Obondlengthwasextended.

简介：使用部分还原－共沉淀方法制备了平均粒径为3－11nm的球形Fe3O4纳米颗粒，以16：4：1的甲醇－乙醇－水混合溶液作为传压介质和均分散介质，利用金刚石对顶砧装置（DAC）研究了球形Fe3O4纳米颗粒的原位常温高压（0－31．8GPa)XRD谱和纳米颗粒的压致晶格结构变化。

简介：EXAFS研究FeCl3溶液中Fe^3+的区域环境结构随溶液浓度的变化，Fe^3+的径向结构函数表明，随着FeCl3溶液的浓度降低，第一配位峰的距离逐渐缩短。当溶液浓度从3.0mol/L降到0.2mol/L时，配位距离减小0.014nm，但振幅峰强度以0.8mol/L浓度为最小，其强度比浓的或稀的FeCl3浓度的低约30％。结构参数拟合结果表明，0.2mol/LFeCl3稀溶液中Fe^3+的近邻配位为6个H2O的O原子形成八面体配位；3.0mol/LFeCl3溶液中Fe^3+的近邻配位为2个Cl^-和4个H2O中的O原子。0.8mol/LFeCl3溶液中Fe^3+的近邻配位有1个Cl^-和5个O原子。其结构无序相对较大，是Cl^-与O组成的扭曲八面体配位。

简介：ThegrowthdetectsinNd:YCa4O(BO3)3(Nd:YCOB)crystalswereinvestigatedbytransmissionsynchrotrontopography.ItwasfoundthatgrowthstriationsweretheprimarydefectsinNd:YCOBcrystals.Grown-indislocations.mosaicblocksandinclusionswerealsoobseredinthecrystals.Theeffectoftemperaturefieldontheformationofgrowthdefectsinthecrystalswasdiscussed.