Pt／钇稳定氧化锆固体电解质在高温下的电化学性质

用交流阻抗技术研究了二电极、三电极Ｐｔ／钇稳定氧化锆（简称ＹＳＺ）高温固体电化学体系．开路电位下，Ｐｔ／ＹＳＺ体系只有一个阻抗半圆，对应于电极体系的电化学活化控制过程，极化电阻随温度变化的表观活化能为１７１．５ｋＪ／ｍｏｌ．Ｐｔ／ＹＳＺ界面的双电层电容约为３００μＦ／ｃｍ２．阳极极化下，交流阻抗极化电阻显著减小；阴极极化下，极化电阻反而增大，并出现浓差控制现象．     

Addition of amines to the triple bond in alpha,alpha,alpha-trichloromethylpropargyl mesylate: synthesis of alpha,alpha-dichloromethylenaminones and preparation of 2-phenyl-4-dichloromethylquinolines

[reaction: see text] Addition of amines to the triple bond in alpha,alpha,alpha-trichloromethylpropargyl mesylate to give alpha,alpha-dichloromethylenaminones and its use in the preparation of 2-phenyl-4-dichloromethylquinolines in good yields are reported.     

Chemical bonding in Si5(2-) and NaSi5(-) via photoelectron spectroscopy and ab initio calculations

Photoelectron spectroscopy and ab initio calculations are used to investigate the electronic structure and chemical bonding of Si5(-) and Si5(2-) in NaSi5(-). Photoelectron spectra of Si5(-) and NaSi5(-) are obtained at several photon energies and are compared with theoretical calculations at four different levels of theory, TD-B3LYP, R(U)OVGF, UCCSD(T), and EOM-CCSD(T), all with 6-311+G(2df) basis sets. Excellent agreement is observed between experiment and theory, confirming the obtained ground-state structures for Si5(-) and Si5(2-), which are both found to be trigonal bipyramid with D3h symmetry at several levels of theory. Chemical bonding in Si5, Si5(-), and Si5(2-) is analyzed using NPA, molecular orbitals, ELF, and NICS indices. The bonding in Si5(2-) is compared with that in the isoelectronic and isostructural B5H5(2-) species, but they are found to differ due to the involvement of electron densities, which are supposed to be lone pairs in the skeletal bonding in Si5(2-).     

硫酸颜色反应用于荧光法测定利血平研究

提出了硫酸颜色反应用于利血平的荧光分析新方法。利用血平与浓硫酸反应，生成强荧光物质，所得产物的荧光强度与利血平的浓度在０－０．６μｇ／ｍＬ范围内有良好的线性关系。检测限为０．２ｎｇ／ｍＬ。本法可直接用于尿液中利血平的定量分析，回收率为８２．５％－８４．２％。     

The structure and magnetic properties of μ3-oxotriiron(III) complex [Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2

A new μ₃-O triiron(III) complex [Fe₃O(OBz)₆(CH₃OH)₃](NO₃)(CH₃OH)₂ (HOBZ = benzoic acid) has been synthesized, its structure has been determined and variable temperature magnetic susceptility has also been measured. In the molecule, three iron atoms formed an equilateral triangle with μ₃-O in center. The fitting to the magnetic susceptibility showed that an intramolecular antiferromagnetic exchange interaction occurred between iron atoms with J=-25.51 cm^?1, and a weaker intermolecular autiferromagnetic exchange interaction occurred with zJ' = ?2.30 cm^?1.     

希夫碱配合物的研究——Ⅵ.K[Fe(acaccn)(CN)2]·2H2O的合成及晶体结构

制备了K[Fe(acaccn)(CN)₂]·2H₂O.并测定了晶体结构.     

盐酸吡哆辛及其制剂的二阶导数差示脉冲极谱法定量研究

建立盐酸吡哆辛及其制剂的二阶导数差示脉冲极谱定量分析方法。盐酸吡哆辛在0.1mol/L氢氧化钠溶液-0.1moL/L磷酸二氢钾溶液-水(体积比为1.2:8.8:990)的混合溶液中,于-0.140V(vs·Ag/AgCl)处出现一良好的二阶导数差示脉冲极谱峰,盐酸吡哆辛浓度在3.6×10~(-4)～9.6×10~(-4)mol/L范围内与其峰幅值呈显著的线性关系(P<0.01),线性相关系数r=0.9997,检出限为9.0nmol/L。     

Resolving the different dynamics of the fluorine sublattices in the anionic conductor BaSnF(4) by using high-resolution MAS NMR techniques

19F and (119)Sn MAS NMR spectroscopy have been used to investigate the fluoride ion conductor, BaSnF(4), a member of the MSnF(4) family of fluorite-related anionic conductors containing double layers of Sn(2+) and M(2+) cations. Two fluorine sublattices were observed by (19)F MAS NMR, which could be assigned to specific sites in the lattice. The first sublattice is due to fluorine atoms located in Ba(2+) double layers and is rigid on the MAS NMR time scale at room temperature. The second sublattice comprises the fluoride ions between the Ba(2+) and Sn(2+) layers, and the few fluorine atoms that inhabit the Sn(2+)-Sn(2+) double layers. These ions are in rapid exchange with each other, and an extremely short correlation time tau(C) for the motion of these ions of <3 x 10(-)(5) s is obtained at -100 degrees C. T(1) measurements indicate that tau(C) approaches 10(-)(8) s at room temperature. (19)F-to-(119)Sn cross-polarization (CP) experiments confirmed the assignments of the resonances, and that the fluorine atoms located next to the tin atoms are extremely mobile at room temperature (and thus do not contribute to the CP process). Two-dimensional (19)F exchange experiments showed that exchange between the rigid and mobile lattice does occur, but at a much slower rate (tau(C) approximately 10 ms at 250 degrees C). Low-temperature (19)F MAS and (19)F-to-(119)Sn CP NMR spectra demonstrate that the motion of the fluoride ions has almost completely frozen out by -150 degrees C. The results are consistent with rapid two-dimensional (anisotropic) conductivity involving the fluoride ions between the Ba and Sn layers. Conductivity in three dimensions requires hops between the ions in the BaF(2)-like layers and the mobile ions. This process does occur, but with exchange rates that are at least 6-7 orders of magnitude slower.     

Photocatalytic degradation of methylene blue on Fe3+-doped TiO2 nanoparticles under visible light irradiation

Fe³⁺-doped TiO₂ composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of Fe³⁺/TiO₂ nanoparticles under visible light irradiation. The influence of doping amount of Fe³⁺ (ω: 0.00%–3.00%) on photocatalytic activities of TiO₂ was investigated. Results show that the size of Fe³⁺/TiO₂ particles decreases with the increase of the amount of Fe³⁺ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe³⁺ can control the conversion of TiO₂ from anatase to rutile. The doping amount of Fe³⁺ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The appropriate doping of Fe³⁺ can markedly increase the catalytic activity of TiO₂ under visible light irradiation. __________ Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)]