碱金属nf里德伯态精细结构反常物理机制的理论研究

采用相对论性多通道理论，系统地研究了碱金属ｎｆ里德伯态的精细结构．所计算的精细结构与已有的实验值（Ｌｉ和Ｎａ的是正常的，Ｒｂ和Ｃｓ的是反常的）符合得很好；目前还没有Ｋ和Ｆｒｎｆ里德伯态的精细结构的实验结果，理论计算预言：Ｋ的是正常的，Ｆｒ的是反常的．还阐明了精细结构反常的物理机制：反常是由价电子与离子实电子之间的交换相互作用引起的，是一种纯相对论效应；电子之间的关联作用对精细结构反常的影响是不重要的 关键词：     

JAHN-TELLER EFFECT AND SUPERCONDUCTING MECHANISM OF THE HOLE-DOPED C60 SOLID

A possible superconducting mechanism of the hole-doped C₆₀ solid is discussed. Under the assumption that the superconductivity results from the strong coupling between electrons at Fermi surface and intramolecular vibrations, a simple expression for the electron-phonon coupling parameter λ is derived. The related transition temperature is estimated and can be much greater than that of the alkali-metal-doped C₆₀ solid.     

Synthesis and Characterization of Binuclear Lanthanide Complexes with Macrocyclic Schiff Base Derived From 2,6-Diacetylpyridine and 1,3-Diamino-2-hydroxypropane

Nine homobinuclear lanthanide complexes with macrocyclic Schiff base were prepared by condensing 2, 6-diacetylpyridine and 1, 3-diamino-2-hydroxypropane in the presence of template lanthanide metal ions. These complexes were characterized by elemental analysis, IR, molar conductance and magnetic susceptibility. The variable-temperature magnetic susceptibility (4-300 K) of complexes of Gd( Ⅲ ) and Dy( Ⅲ ) was determined. A satisfactory fit to theoretical curve derived from spin Hamiltonian operator was obtained using least-squares method. The exchange interaction parameters are J=-0.26 cm-1, g=1.98 and △=0.06 cm-1, Z.J'=-0. 21 cm-1,g'=1.33 for Gd( Ⅲ ) and Dy( Ⅲ ), respectively. The results indicate a very week antiferromagnetic interaction between Gd( Ⅲ )-Gd( Ⅲ ) and Dy( Ⅲ )-Dy( Ⅲ ) ions.     

FORMATION AND MAGNETIC PROPERTIES OF Dy2Fe17-xMnxC(x = 0-17) PREPARED BY ARC-MELTING

We report on alloys formed by replacing iron with manganese in the compound Dy₂Fe₁₇C_1.0 Samples were characterized by X-ray diffraction and magnetic measure-ments, The 2:17-type structure can be crystallized in the whole range of manganese substitution. The Curie temperature of the series of Dy₂Fe_17-xMn_xC_1.0(x= 0-17) drops down considerably from 515K for x = 0 to about 20K for compounds with high manganese concentration, and the compensation point was observed in a narrow range of x≈4-6. The rapid decrease of the magnetization shows that the manganese substitution is not a simple magnetic dilution to the transition-metal sublattice mo-ment, it indicates that the moment of Mn may be antiparallel to that of Fe. The field dependence of the magnetization of Dy₂Fe_17-xMn_xC_1.0 may indicate the existence of the nonlinear magnetic structure for the samples with high Mn conoentrations.     

光纤孤子间的相互作用

用最小作用量原理导出了非线性Schr?dinger方程两个孤子间的相互作用它作为孤子间距△与初位相差δ的函数揭示出来，当两个孤子δ<π/2时相互吸引,δ>π/2时相互排斥，δ=π/2时几乎不存在相互作用；相互作用的大小随△的增大而指数地衰减.本文的结果与实验的定量比较表明两者符合甚好     

示波极谱法同时测定痕量硒和砷

在盐酸-酒石酸锑钾介质中,Se(Ⅳ)在—0.59V(vs.SCE,下同)左右产生示波极谱峰,其二阶导数峰高IP″_(Se)与Se(Ⅳ)浓度在1.26×10~(-8)～1.26×10~(-4)mol·L~(-1)范围呈良好线性关系,Se(Ⅳ)检出下限为5.0×10~(-9)mol·L~(-1)。在相同底液中,当Se(Ⅳ)浓度大于2.5×10~(-6)mol·L~(-1)时,As(Ⅲ)在—0.79V左右也出现一良好极谱峰,其峰高IP″_(As)与As(Ⅲ)浓度在5.3×10~(-7)～2.6×10~(-4)mol·L~(-1)之间呈良好线性关系,As(Ⅲ)检出下限为2.7×10~(-7)mol·L~(-1)。Se(Ⅳ)、As(Ⅲ)两峰电位相差较大,可在同一底液中同时测定。曾用本法测定了煤飞灰标样(82201)中痕量硒和砷,结果与证书值相符。硒、砷加标回收率为95％～110％,还研究了Se(Ⅳ)、As(Ⅱ)极谱波性质。     

Synthesis and Crystal Structure of a Heteropentanuclear Yb(Ⅲ)-Cu (Ⅱ) Complex:[Yb_2Cu_3(O_2CCH_2CI)_(12)(H_2O)_8]·2H_2O

1INTRODUCTIONInterestinpolynuclearcomplexesisstimulatedbytherolestheyplayindifferentfields,e.g.heterogeneouscatalysis,bioinorganicchemistryandthedesignofmagneticmaterials.Since1985ill,considerableattentionshavebeengiventomolecularcomplexest'isimultaneouslycomprisingdandfmetalionsduetotheirspecialmagneticproperties.Coupledpolyr^uclearsystemscontaining3delementshavebeenextensivelyinvestigatedL,3,butonlyafew,derivedfromcarboxylatesL4--63,thatcontainbothtransitionandrare--earthmetalionshavebe…     

提高全息图衍射效率的一种方法

本文介绍用稀释显影提高全息图衍射效率的方法。给出了稀释显影的特性曲线以及衍射效率与显影时间、曝光量之间的关系。得到了三种全息干板的高衍射效率。 关键词：     

热等静压对NbTi/Cu多芯超导线加工过程的影响

采用传统方法生产的NbTi/Cu多芯超导线在生产芯数较多的超导线时存在填充系数较大的问题,这直接影响了芯丝的整齐排布,所以组装完成后加入热等静压过程.研究了经过热等静压和未经过热等静压的NbTi/Cu多芯超导线的加工性能.经过试验证明,经过100～150MP,2小时热等静压处理的NbTi/Cu多芯超导线坯锭在加工过程中具有良好的加工性能,提高了超导线复合坯锭的成品率;而未经过热等静压处理的NbTi/Cu多芯超导线坯锭加工性能较差,坯锭内部缺陷较多.     

Ⅱ型糖尿病肾病小鼠肾水提物代谢组学研究

应用基于核磁共振的代谢组学方法研究Ⅱ型糖尿病模型db/db小鼠已发展到糖尿病肾病时肾脏代谢表型的变化.结合偏最小二乘法-判别分析(PLS-DA),结果显示,与正常组相比,模型组肾水提物中的乳酸和糖等代谢物的含量显著升高,而谷氨酸、乙酸、胆碱和甘氨酸的含量显著降低,缬氨酸、肌酐、尼克酰胺、苯丙氨酸和酪氨酸含量略有降低.实验结果表明糖尿病肾病动物模型db/db小鼠的代谢特征不同于正常小鼠.代谢组学分析方法作为辅助手段,为糖尿病肾病的发病机制提供了良好的数据支持.