利用多重示踪技术研究正常鼠和肿瘤鼠的微量元素代谢(英文)

利用25 MeV/u40Ar +Se中能重离子核反应,制备包含24种元素在内的多重示踪剂,通过对元素γ谱的分析,研究了正常鼠和肿瘤鼠体内微量元素的分布及代谢。Mg,Sr, Ga, As,Sc, V, Cr, Mo, Co,Fe, Y,Zr, Nb和Ru等元素在肿瘤鼠的粪便和尿液中的排泄时间与正常鼠不同。肿瘤鼠与正常鼠相比,Na, Mn,Fe和Co的排泄变化较大,肿瘤鼠的排泄率较正常鼠高;而Ca, Y,Zr和Mo的排泄率肿瘤鼠则较正常鼠低;在正常鼠脏器、组织和血液样品中测出了Na,Rb,Ga,Sc, As,Zn, V,Cr, Mn,Co,Fe、Y,Zr, Tc, Ru, Ag和In等17种元素,肿瘤鼠检测出了除Zn和As之外的其它15种元素。几乎所有的元素在正常鼠中的吸收均比肿瘤鼠高。大部分元素分布在肝、肾和毛皮以及实体瘤中,而Fe和Na在肿瘤组织则没有检测到。

YBa_2Cu_3O_7的化学键性质和穆斯堡尔谱的研究

利用电介质的平均能带模型计算了YBa2 Cu3O7的化学键参数 ,得到Cu(1)—O键的平均共价性为 0 40 6,Cu(2 )—O键的平均共价性为0 2 76。应用化学环境因子计算了Fe :Y 12 3的穆斯堡尔同质异能位移 ,确定了5 7Fe在Y 12 3中的价态和占位情况。由电声子强度参数与共价性的关系说明了超导相中Cu(2 )离子的重要性

二(2-乙基己基)膦酸从盐酸介质中萃取钪(Ⅲ)、钇(Ⅲ)、镧系离子(Ⅲ)和铁(Ⅲ)

本文研究了二(2-乙基己基)膦酸(H[DEHP])的正辛烷溶液从盐酸介质中萃取钪(Ⅲ)、钇(Ⅲ)、镧系离子(Ⅲ)和铁(Ⅲ)的平衡规律。结果表明,H[DEHP]对上述离子的萃取次序是Sc~(3+)>Fe~(3+)>Lu~(3+)>Yb~(3+)>Er~(3+)>Y~(3+)>Ho~(3+)。讨论了Sc(Ⅲ)与Fe(Ⅲ)、Y(Ⅲ)、Ln(Ⅲ)(镧系离子)以及Fe(Ⅲ)与重镧系离子(Ⅲ)分离的可能性,并与HEH[EHP]萃取上述离子的性能进行了比较。借助IR、NMR和斜率法,饱和法研究了低酸度下H[DEHP]萃取Sc(Ⅲ)、Y(Ⅲ)和Ln(Ⅲ)的平衡反应,计算了浓度平衡常数和萃取反应的热力学函数。

Fe-57 Mossbauer spectroscopic and magnetic studies of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

Mossbauer spectra for Fe atoms in the series of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) compounds were collected at 4.2 K. The ratio of 14.5 T/mu(B) between the average hyperfine field B-hf and the average Fe magnetic moment mu(Fe)(MS), obtained from our data, in Y3Fe29-xVx is in agreement with that deduced from the RxTy alloys by Gubbens et al. The average Fe magnetic moments mu(Fe)(MS) in these compounds at 4.2 K, deduced from our Mossbauer spectroscopic studies, are in accord with the results of magnetization measurement. The average hyperfine field of the Fe sites for R3Fe29-xVx at 4.2 K increases with increasing values of the rare earth effective spin (g(J) - 1) J, which indicates that there exists a transferred spin polarization induced by the neighboring rare earth atom.

Mossbauer spectroscopy study of Fe-57 in R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

Fe-57 Mossbauer spectra for the Fe atoms in the R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb, Dy; T=V, Cr) compounds were collected at 4.2 K. The analysis of Mossbauer spectra was based on the results of magnetization and neutron powder diffraction measurements. The average Fe magnetic moments at 4.2 K, deduced from our data, are in accord with magnetization measurements. The average hyperfine field of Tb3Fe29-xCrx (x=1.0, 1.5, 2.0, and 3.0) decreases with increasing Cr concentration, which is also in accordance with the variation of the average Fe magnetic moment in the Tb3Fe29-xCrx compounds.

H[DEHP]从不同介质中萃取稀土（III）(Sc、Y、Ho、Er、Yb、Lu)及Fe(III)、Zn(II)的机理

本文分另研究了H[DEHP]从不同酸性介质中萃取稀土（III）(Sc、Y、Ho、Er、yb、Lu)及Fe(III)、Zn(II)的机理及性能。一、H[DEHP]从 H_2SO_4介质中萃取Sc(III)的机理 1. H[DEHP]萃取H_2SO_4及其机理 2. H[DEHP]萃取Sc(III)的机理，用斜率法和饱和法确定了H[DEHP]的正庚烷溶液从H_2SO_4溶液中萃取Sc_2(SO_4)_3的机理及萃合物组成。研究表明，H[DEHP]萃取Sc(III)在高、低两种酸度范围内存在着两种不同的萃取机理。二、H[DEHP]从HCl介质中萃取Ln(III)和Fe(III)的性能及H[DEHP]萃取Ln(III)的机理研究了H[DEHP]的正庚烷溶液从HCl介质中萃取稀土（III）(Sc、Y、Ho、Er、Yb、Lu)和Fe(III)的性能，得出H[DEHP]在相同条件下萃取以上各金属离子的顺序是：Sc(III)>Fe(III)>Lu(III)>Yb(III)>Er(III)>Y(III)>Ho(III), 并计算了各金属离子之间的分离因素（β）。文中还讨论了Sc(III)、Fe(III)、Lu(III)之间的分离以及重稀土离子间的萃取分离，同时与相同实验条件下HEH[EHP]的萃取性能进行了比较，为新的萃取体系提供了一些参数。三、H[DEHP]从不同介质中萃取Fe(III)的机理，研究了H[DEHP]的正率烷溶液从Hcl介质中和H[DEHP]的正庚烷溶液从H_2SO_4介质中萃取Fe(III)的平衡规律；用斜率法、饱和法以及IR和NMR谱等讨论了低酸度下的萃取机理。四、H[DEHP]萃取Zn(II)的机理，研究了H[DEHP]的正率烷溶液从Hcl介中萃取Zn(II)的平衡，利用斜率法、饱和法及SR、NMR谱等讨论了低Hcl浓度下的萃取机理。

Y在固体电极的电化学过程及Y_(mm)-Ni和Y_(mm)-Fe合金制备

本文对YCl_3-KCl.NaCl熔体中Y在固体M_0，Ni和Fe电极上的电化学过程及用氯化的熔休电解制备Y_(mm)-Ni和Y_(mm)-Fe合金进行了系统研究。对电解时电解槽内熔体温度分布进行了测定，得出了电解制备Y_(mm)-Ni合金时槽内熔体温度分布图。结果表明，从阴极表面到电解槽内表面的温度递降不是均匀的，阴极附近出现一个高温区。随着边缘电解质温度的升高，阴极表面温度基本上平行地上升。电极表面温度超出边缘电解质温度随电解时阴极电流密度和电流强度的增大而增加，在一定范围内有很好的线性关系；当使用高阴极电流密度时，可高达近百度。

钙钛石型复合氧化物La_xSr_(1-x)M_yM'_(1-y)O_3(M, M' = Mn, Fe, Co)的固体物理化学性质和催化性能的研究

钙钛石型复合氧化物由于具有许多独特的物理化学性质，如多种类型的磁性和导电性、对多种物理和化学因素的敏感性、高温下的稳定性和结构的明确易调性等长期以来一直受到固体物理、固体化学和催化科技工作者重视，本文第一部分详细总结了文献中有关这类氧化物的结构、电子状态、电磁性质、表面吸附性能、稳定性以及反应机理和催化性能等方面的重要结果。第二部分为催化剂的制备和表征方法。第三部分针对文献中研究较少的B位取代钙钛石型氧化物，系统研究了系列化合物LaM_yM'_(1-y)O_a (M, M' = Mn, Fe, Co)的固体物理化学性质和对NH3和CO氧化反应的催化性能，讨论了它们之间的关系。1. 催化剂的制备、晶体结构与光谱性质。2. LaM_yM'_(1-y)O_3(M、M' = Mn、Fe、Co)r的氧化还原性质和稳定性。3. 过渡金属离子的状态及其之间的相互作用。4. 催化剂中氧的形态。5. 氨氧化性能与固体物化性质之间的关系。6. 一氧化碳氧化与固体物化性质之间的关系。

Fe-57 Mossbauer spectroscopic and magnetic studies of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

Mossbauer spectra for Fe atoms in the series of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) compounds were collected at 4.2 K. The ratio of 14.5 T/mu(B) between the average hyperfine field B-hf and the average Fe magnetic moment mu(Fe)(MS), obtained from our data, in Y3Fe29-xVx is in agreement with that deduced from the RxTy alloys by Gubbens et al. The average Fe magnetic moments mu(Fe)(MS) in these compounds at 4.2 K, deduced from our Mossbauer spectroscopic studies, are in accord with the results of magnetization measurement. The average hyperfine field of the Fe sites for R3Fe29-xVx at 4.2 K increases with increasing values of the rare earth effective spin (g(J) - 1) J, which indicates that there exists a transferred spin polarization induced by the neighboring rare earth atom.

Mossbauer spectroscopy study of Fe-57 in R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

Fe-57 Mossbauer spectra for the Fe atoms in the R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb, Dy; T=V, Cr) compounds were collected at 4.2 K. The analysis of Mossbauer spectra was based on the results of magnetization and neutron powder diffraction measurements. The average Fe magnetic moments at 4.2 K, deduced from our data, are in accord with magnetization measurements. The average hyperfine field of Tb3Fe29-xCrx (x=1.0, 1.5, 2.0, and 3.0) decreases with increasing Cr concentration, which is also in accordance with the variation of the average Fe magnetic moment in the Tb3Fe29-xCrx compounds.

Comparative study on the doping effect of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M=Sc,Ti,V,Cr,Mn,Fe,Co,Ni, or Zn)

With XRD, R-T, and ac chi measurements a comparative study on the doping effects of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, or Zn) has been carried out. The effects of the former five members are significantly different, both on phase formed and on T-c, from the latter four. It seems that the effect on phase stabilization correlates with the valency of the doped cation. In connection with the instability of the 2223 phase, the correlation has been discussed.

PREPARATION, CRYSTAL-STRUCTURE, AND VIBRATIONAL-SPECTRA OF PEROVSKITE-TYPE MIXED OXIDES LAM(Y)M'(1-Y)O(3) (M,M'=MN, FE, CO)

Three series of samples LaMnyCo1-yO3+/-lambda, LaFeyMn1-yO3+/-lambda, and LaFeyCo1-yO3+/-lambda (y = 0.0 to 1.0) with Perovskite structure were prepared by an explosion method different from the generally used ceramic techniques. The variation of crystal

Mossbauer spectroscopic study of R3Fe29-xCrx and R3Fe29-xCrxH,(y)(R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

Fe-57 Mossbauer spectra for the series of R3Fe29-xCrx (R = Y,Ce, Nd, Sm, Gd, Tb, and Dy) compounds and their hydrides have been measured at 4.2 K. The weighted average hyperfine field at the Fe sites was separated into a 3d-electron contribution, proportional to the average Fe moment, and a transferred contribution due to rare earth moments. The latter was found to increase with the rare earth effective spin (g(J) - 1) J. Hyperfine fields in the hydrides were only slightly larger than in the corresponding alloys.

Crystallographic and magnetic properties of the hydrides R3Fe29-xCrxHy (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

A systematic study of the structural and intrinsic magnetic properties of the hydrides R3Fe29-xCrxHy (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed. Hydrogenation lends to a relative volume expansion of the unit cell and a decrease in x-ray density for each compound. Anisotropic expansions mainly along the n- and b-axes rather than along the c-axis for all of the compounds upon hydrogenation are observed. The lattice constants and the unit-cell volume of R3Fe29-xCrx and R3Fe29-xCrxHy decrease with increasing R atomic number from Nd to Dy, except for Ce, reflecting the lanthanide contraction. Hydrogenation results in an increase in the Curie temperature and a corresponding increase in the saturation magnetization at room temperature for each compound. After hydrogenation a decrease of 0.34 mu(B)/Fe in the average Fe atomic magnetic moment and a slight increase in the anisotropy field for Y3Fe27.2Cr1.8 are achieved at 4.2 K. First-order magnetization processes (FOMP) occur in magnetic fields of around 1.5 T and 4.0 T at 4.2 K for Nd3Fe24.5Cr4.5H5.0 and TD3Fe27.0Cr2.0H2.8, and around 1.4 T at room temperature for Gd3Fe28.0Cr1.0H4.2. The abnormal crystallographic and magnetic properties of Ce3Fe25.0Cr4.0 and Ce3Fe25.0Cr4.0H5.4 suggest that the Ce ion non-triply ionized.

Crystallographic and magnetic properties of R3Fe29-xVxN4 (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

A systematic investigation of crystallographic and magnetic properties of nitride R3Fe29-xVxN4 (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed. Nitrogenation leads to a relative volume expansion of about 6%. The lattice constants and unit cell volume decrease with increasing rare-earth atomic number from Nd to Dy, reflecting the lanthanide contraction. On average, the Curie temperature increases due to the nitrogenation to about 200 K compared with its parent compound. Generally speaking, nitrogenation also results in a remarkable improvement of the saturation magnetization and anisotropy fields at 4.2 K and room temperature for R3Fe29-xVxN4 compared with their parent compounds. The transition temperature indicates the spin reorientations of R3Fe29-xVxN4 for R = Nd and Sm are at around 375 and 370 K which are higher than that of R3Fe29-xVx, for R = Nd and Sm 145 and 140 K, respectively. The magnetohistory effects of R3Fe29-xVxN4 (R = Ce, Nd, and Sm) are observed in low fields of 0.04 T. After nitrogenation the easy magnetization direction of Sm3Fe26.7V2.3 is changed from an easy-cone structure to the b-axis. As a preliminary result, a maximum remanence B-r of 0.94 T, an intrinsic coercivity mu(0)H(C) of 0.75 T, and a maximum energy product (B H)(max) of 108.5 kJ m(-3) for the nitride magnet Sm3Fe26.7V2.3N4 are achieved by ball-milling at 293 K.