双核配合物[Cu2(TS)(H2O)]·CH3OH的自组装制备和晶体结构

The binuclear complex [Cu₂(TS)(H₂O)]·CH₃OH, where TS denotes the binucleating ligand derived from the schiff base N,N′-bis(3-carboxylsalidene)trimethylenediamine, was obtained from the self-decomposition of mononuclear complex Na₂CuTS·H₂O. It crystallizes in the monoclinic system, space group P2₁/c. The lattice parameters are a=11.935(2)?,b=15.667(3)?,c=11.621(2)?,β=111.60(3)°,V=2020.2(7)?³, Z=4 with R=0.0467. The structure is made of binuclear units, in which two copper atoms are bridged by two phenolic oxygen atoms. The “inside”copper atom is coordinated by two nitrogens, two phenolic oxygens in a planar coordi-nation site, the copper atom deviates from the mean plane by 0.47?. The “outside” copper atom is five coordinated by two phenolic oxygen atoms、two equatorial carboxyl oxygen atoms and one axial water oxygen atom in a distorted tetragonal cone site, the copper atom is pulled out of the equatorial plane by 0.46?.     

Texture of zirconia obtained by forced hydrolysis of ZrOCl2 solutions

The structure and surface properties of ZrO₂ strongly depend on its preparation. In the present work the impact of prolonged aging at basic conditions (pH = 9, T = 100°C, t = 48 h), on the phase composition and textural properties, obtained by calcination of the precipitate, was investigated using several techniques conjointly (DTA/TG, DSC, XRD, porosimetry). The thermal effects accompanying the ZrO₂·xH₂O gel formation, the coalescence of the particles and crystallization were evaluated and discussed in terms of the structural differences between the aged and non-aged samples. This revised version was published online in July 2006 with corrections to the Cover Date.     

复合固体超强酸催化剂SO_4~(2-)_4-WO_3-ZrO_2的结构研究

已报导，经适当处理的SO42-ZrO2和WO3－ZrO2具有超强酸性［1］．在此基础上将SO42-和WO3同时负载于ZrO2表面，发现其表面酸性有明显增强，得到的固体超强酸504－W0s－Zro。在很宽的焙烧温度范围内（700七00“C）都具有HO三一16．04的酸强度，吸附毗院的红外光谱研究表明，其表面同时具有强的L酸性和B酸性问，140“C时，对正乙烷裂解及异构化的催化活性比SO4－－ZrO。和WO3－ZI02都高，表现出相当的协同效应同．本文用XRD，DTA－TG，比表面测定等技术研究催化剂的组成、结构形态及其随焙烧温度的变化．并与504－Zro：和WO。…     

Lattice dynamical study of body-centred tetragonal indium

The phonon dispersion curves, phonon frequency distribution function as well as the lattice specific heat of body-centred tetragonal indium have been deduced using a lattice dynamical model which includes central, angular and volume forces. Six elastic constants, four zone boundary frequencies and an equilibrium condition were used in the evaluation of the force constants. It is shown that this model is elastically consistent and satisfies the symmetry requirements of the lattice, the phonon frequencies of indium deduced from it are in very good agreement with the experimental values of Reichardt and Smith and the theoretical values of Garrett and Swihart, and theθ _D values compare well with the experimental values over a wide temperature range. The apparent discrepancies in the phonon dispersion curves and theθ _D-T curves obtained from deficient models, importance of umklapp processes and the significance of angular forces in the lattice dynamical models are discussed.     

枝晶簇四方相钛酸钡的制备及其电场响应性能的研究

为了提高BaTiO3粒子在含水复合弹性体中的电场响应能力,本文采用简单的水热合成法,在不引入任何表面活性剂的情况下,仅通过对反应温度和溶液pH值的调控获得了新颖形貌的钛酸钡粒子。通过借助X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)及接触角(Contact Angle)测量等手段对粒子的微观结构和表面特性进行表征发现:该粒子为高纯四方相枝晶簇结构,具有良好的亲水性,而且在含水复合弹性体中对电场具有优良的响应能力。     

钛酸铅和钛酸钡振动性质及铁电相变的密度泛函理论研究

采用密度泛函赝势的方法, 研究了不同晶相的钛酸铅和钛酸钡的振动模式. 没有发现钛酸铅存在低温相变的证据, 而钛酸钡则存在四方-正交和正交-三角铁电相变. 振动频率随四方应变的变化关系表明, 随着四方应变的增大, 软模的频率增大, 在某一个临界点, 不稳定的软模转变为稳定的振模. 由于钛酸铅具有较大的四方应变, 使得其能够在四方相稳定下来, 而钛酸钡较小的四方应变是其仍能够发生低温铁电相变的一个重要原因.     

亚微米级四方相钛酸钡低温固相法制备及晶型控制

以八水合氢氧化钡和α-钛酸为原料,在相对低的焙烧温度下,制备出近似球形、亚微米级的钛酸钡。通过XRD、SEM、Raman和FTIR等手段对钛酸钡样品进行表征,样品具有高结晶度,颗粒均一性良好。晶型转变的初步探究表明,立方相为主的钛酸钡可以在400℃发生晶相转变,成为以四方相为主的钛酸钡。     

Young＇s modulus surface and Poisson＇s ratio curve for tetragonal crystals

This paper gives the general expressions for the compliance s′ijkl, Young＇s modulus E（hkl） and Poisson＇s ratio v（hkl, θ） along arbitrary loading direction [hkl] for tetragonal crystals. The representation surface for which the length of the radius vector in the [hkl] direction equals E（hkl） and representation curve for which the length of the radius vector with angle θ deviated from the reference directions [001^-], [100], [001^-], [101^-] and [112^-] equals v（100, θ）, v（001, θ）, v（110,θ）, v（101,θ） and v（111, θ） respectively, are constructed for nine tetragonal crystals （ammonium dihydrogen arsenate, ammonium dihydrogen phosphate, barium titanate, indium, nickel sulfate, potassium dihydrogen arsenate, potassium dihydrogen phosphate, tin and zircon）. The characteristics of them are analysed in detail.     

Self consistent modified extended Hückel (SC-MEH) calculations on heavy metal systems. I. Platinum(II) tetragonal planar complexes with and without relativistic effects

The Self Consistent Modified Extended Hückel molecular orbital method had been applied to several square planar complexes of platinum (II). Calculations including both the limited 5d, 6s, 6p and extended 5s, 5p, 5d, 6s, 6p starting bases for platinum were made. It is shown that in PtCl ₄ ^2– both the nuclear quadrupole moment and minimum total energy vs. bond distance are calculated to be in good agreement with experiment, only with the extended platinum AO basis.Specific inclusion of relativistic parameters via a pseudo-relativistic approximation are shown to have a significant effect on the energy molecular energy levels, however no meaningful rationalization can be made without the simultaneous inclusion of ligand field parameters as well.Supported in part by a grant made available through the Cancer Association of Greater New Orleans. Use of the facilities of the Computer Research Center of the University of New Orleans is gratefully acknowledged.