材料期刊网

不稳定锂同位素移位的高精度测量实验方案

王海鸣 , A.Dax , G.Ewald , I.Katayama , R.Kirchner , W.Nortershauser , H.J.Kluge , T.Kühl , R.Sanchez , I.Tanihata , M.Tomaselli , C.Zimmermann

原子核物理评论 doi:10.3969/j.issn.1007-4627.2002.02.055

对丰中子晕核11Li的核电荷均方根半径的实验确定, 特别是其与9Li的半径的差值, 将对各种核模型进行灵敏的检验. 选择锂的合适跃迁, 利用激光光谱技术高精度测量该跃迁的同位素移位, 并扣除精确理论计算的质量移位贡献值, 可以用来确定有关同位素的核电荷均方根半径. 就目前能够提供的实验设备和手段, 对于不稳定锂的同位素8,9Li和短寿命丰中子晕核11Li而言, 这是能够得到与核模型相独立的电荷半径值的唯一可行的方法. 这类实验正在德国重离子研究中心(GSI)和欧洲核子中心的ISOLDE/CERN 上计划实施.描述了锂原子的激光激发共振电离途径和进行锂的同位素移位测量的实验装置, 并讨论了采用这种方法测量到的6,7Li的初步结果及其精度, 以及使用该方法研究不稳定核的灵敏性.

关键词: 晕核 , 同位素移位 , 电荷半径

R-line thermal shift and thermal broadenings of R, R' and B lines for ruby

Communications in Theoretical Physics

The unified theoretical calculation of thermal shifts (TS) of R-1 and R-2 lines and thermal broadenings (TB) of R, R' and B lines for ruby was carried out for the first time. The calculated results are in very good agreement with a great number of experimental data. Especially by using quantum theory and taking into account all the admixtures of wavefunctions within d(3) electronic configuration, all the Gamma M in electron-phonon interaction (EPI), the electronic energy spectrum and lattice-vibration Spectrum, the very important contributions to TS and TB from single-phonon direct process were theoretically calculated in detail. The microscopic essentials of various contributions are revealed, and the mistakes in previous work are remedied.

关键词: diamond anvil cell;pressure measurement;spectroscopy;temperatures

Theoretical calculations of thermal broadenings and transition probabilities of R, R ' and B line-groups for ruby

Communications in Theoretical Physics

On the basis of the unified calculation of the thermal shifts of R-1 line, R-2 line and ground-state-splitting as well as the thermal broadenings of R, R' and B line-groups for ruby, by taking into account all the levels and admixtures of wavefunctions within d(3) electronic configuration and all the GammaM in electron-phonon interaction, the transition probabilities of direct and Raman processes have theoretically been calculated. The thermal broadenings, of R, R' and B line-groups have successfully been interpreted in terms of the direct and Raman processes of acoustic phonons. The theoretically predicted transition probabilities are in good agreement with the experimental ones.

关键词: crystal fields;electron-phonon interaction;thermal broadening;transition probability;direct and Raman processes;shifts

Phase diagram of R-Fe-Co pseudoternary system with R <= 33.3% (mole fraction, R = Sm0.5Dy0.5)

Transactions of Nonferrous Metals Society of China

Phase equilibria of the R-Fe-Co pseudoternary system with R less than or equal to 33.3% ( mole fraction, R = Sm0.5Dy0.5) were determined in an isothermal section at 1073 K and a vertical section of RFe2-RCo2 by using OM, X-ray diffractometer, EP-MA DTA techniques. There are seven intermetallic phases: (Sm, Dy) (Fe, Co)(2), (Sm, Dy) (Fe, Co)(3), (Sm, Dy)(6) (Fe, Co)(23), (Sm, Dy)(2) (Fe, Co)(7), (Sm, Dy) (Fe, Co)(5), Th2Ni17-type and Th2Zn17-type (Sm, Dy)(2)(Fe, Co)(17). The (Sm, Dy)(6)(Fe, Co)(23) phase dissolves 36% Co(mole fraction) at 1073 K. However, the (Sm, Dy)(2)(Fe, Co)(7) phase in R-2(Fe1-xCox)(7) alloys dissolves about 19% Fe(mole fraction) at 1073 K.

关键词: rare earth-iron-cobalt;phase diagram;structure;compounds;sm-co;magnetic-properties;binary-system;magnetostriction

NEUTRON DIFFRACTION STUDY ON R_2Fel_(17)N_x(R=Y,Dy,Nd)

YANG Jilian ZHANC Baisheng DINC Yongfan China Institute of Atomic Engergy , Beijing , ChinaYANG Yingchang ZHANG Xiaodong Peking University , Beijing , ChinaPAN Shuming General Research Institute for Non-Ferrous Metals , Beijing , China associate professor , P.O.Box 275 , Branch No.30 , Beijing 102413 , China

金属学报(英文版)

The N occupying sites and magnetic structures in R_2Fe_(17)N_x(R=Y,Dy,Nd)are de- termined by neutron diffraction.The effects of the site occupation of N on magnetic properties are discussed primarily.

关键词: neutron diffraction , null , null , null , null , null

SPIN REORIENTATION AND EXCHANGE INTERACTIONS IN (ND, R)2FE14B (R = Y, GD)

Journal of Magnetism and Magnetic Materials

Exchange fields in both (Nd, Y)2Fe14B and (Nd, Gd)2Fe14B series are determined by analyzing spin reorientation. Results calculated for the two systems suggest that the R-R exchange interactions between R ions are comparable with the crystal-field interaction and that their effect might be taken into account for reproducing the spin-reorientation temperature.

关键词: magnetization process;crystal;nd2fe14b;r2fe14b;transition

R&D STATUS ON INTERMETALLICS IN CHINA

CHEN Guoliang(State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 , China)SHI Changxu (Academia Sinica , Beijing 100864 , China)

金属学报(英文版)

This paper briefiy introduces the R&D of intermetallics in China. R&D on intermetallics in a national scale in China began near ten years ago. The investigation in past years focused on the fundamental research and materials development. A significant progress has been made. Various components that made of Ti3Al Ni3Al, TiAl and Fe3Al have been successfully manufactured Some of them have been evaluted. It is expected that some intermetallic alloys will be produced in an industrial scale in the near future.

关键词: :intermetallic alloys , null , null , null

R & D ACTIVITIES ON AEROSPACE MATERIALS IN KOREA

H.M. Kim(Korea Institute of Machinery and Materials , Korea Manuscript received 26 August 1996)

金属学报(英文版)

This paper briefly reviews research and development programs in Korean aerospace industry,with an emphasis on aircraft materials technology. International collaborations in these areas are outlined and the R & D activities are highlighted against the　background of the national economy.It is shown that the investment from government agencies and large enterprises has led to healthy development of aerospace materials industries in Korea.

关键词: :R & D , null , null , null

Isofrax(R)和Insulfax(R)生物可溶性纤维的研究

朱炯 , 汤小明

材料工程 doi:10.3969/j.issn.1001-4381.2010.z2.095

综述生物可溶性纤维的研究进展,介绍矿物纤维对人体健康的影响以及国际上对矿物纤维进行健康分类的主要规范.分析了Unifrax公司研制Insulfrax(R)和Isofrax(R)两种可溶性耐火纤维的基本性能和应用情况.Isofrax(R)和Insulfrax(R)均是绿色环保型隔热材料,在欧美已成功地应用于各种热处理工业中.

关键词: 可溶性 , 纤维 , Insulfrax(R) , Isofrax(R)

Subsolidus phase relations and crystal structures of R-Ca-Cu-O (R = Nd, Sm, Gd, Tm) systems

Journal of Solid State Chemistry

The subsolidus phase relations of R2O3-CaO-CuO ternary systems (R = Nd, Sm, Gd, Tm) have been investigated by X-ray powder diffraction. All samples were synthesized at about 950degrees in air. There exists a ternary compound Ca14-xRxCu24O41 (x = 4 for R = Nd, Gd and x = 5 for R = Sm) and a ternary solid solution Ca2+xR2-xCu5O10 (R = Nd, Sm, Gd, Tm) with a wide composition range Deltax of about 0.6. The compound Ca14-xRxCu24O41 possesses a layered orthorhombic structure and is isostructural to Sr14-xCaxCu24O41. The lattice parameters a and c of the compound are basically independent of the ionic radius of R, while the lattice parameter b and unit-cell volume V decrease substantially with the decrease of the ionic radii of R. The Ca2+xR2-xCu5O10 solid solution is isostructural to Ca2+xY2-xCu5O10, the structure of which is based on an orthorhombic "NaCuO2-type" subcell containing infinite one-dimensional chains of edge-shared square planar cuprate groups crosslinked by the layered cations Ca and R that locate in the inter-chain tunnels. (C) 2002 Elsevier Science (USA). All rights reserved.

关键词: R2O3-CaO-CuO (R = Nd, Sm, Gd, Tm) systems;phase relations;Ca10R4Cu24O41 (R = Nd, Sm, Gd) structure;Ca2+xR2-xCu5O10 (R = Nd, Sm,;Gd, Tm) structure;ternary-system;approximately 950-degrees-c;high-pressure;superconductivity;diagram;air;er;compatibilities;property;oxide