Valence of elements in HgBa2Can-1CunO2n+2+delta (n=1, 2, 3, 4)

Valence of elements in HgBa2Can-1CunO2n+2+delta (n=1, 2, 3, 4) (both argon and oxygen annealed samples) were calculated. The result indicated for both argon and oxygen annealed samples, Hg had the lowest valence for the highest T-c sample. For fixed n, the valence of Cu in oxygen annealed samples was larger than that in argon annealed samples, indicating that oxygen annealed samples produce more carriers than argon annealed samples.

人体血浆中15种超痕量稀土元素的电感耦合等离子体质谱法测定

本文用电感耦合等离子体质谱法测定了人体血浆中的稀土元素。在优化的条件下 ,以内标法测得的各种纯水溶液的检测限在 0 .7(Eu)～ 5 .4(Gd) ng·L- 1范围内。研究了 K,Na,Ca,Fe等基体元素对稀土测定的影响。以 In为内标元素补偿样品基体效应以及灵敏度飘移。比较了直接稀释、HNO3- H2 O2 消解及 HNO3-HCl O4消解 3种样品处理方法 ,用 1% HNO3直接稀释样品可满足轻稀土元素的定量分析要求 ,方法的定量测定下限≤ 1μg·L- 1。

Valences of Cu in Y1-xCaxBa2Cu3O6+y

The valences of Cu in Y1-xGaxBa2Cu3O6+y have been investigated by using complex chemical bond theory The results for the valences of Cu(1) and Cu(2) in the calculation suggest that the holes introduced by calcium substitution only reside in CuO2 planes, and there is a competition mechanism for the hole density in CuO2 planes between Ca doping and oxygen depletion. These conclusions are satisfactorily in agreement with experiments.

Dependence of superconducting temperature on chemical bond parameters in YBa2Cu3O6+delta (delta=0-1)

The chemical bond parameters, that is ionicities and average energy gaps, for all types of chemical bonds in YBa2Cu3O6+delta have been investigated with variation of oxygen content delta (delta = 0.0, 0.35, 0.45, 0.58, 0.64, 0.73, 0.78, 0.81, 0.95, 1.00). The theory used is the complex crystal chemical bond theory, which is the development of P-V-L theory. The two plateaus near 90 K and 60 K in superconducting transition temperatures, and the disappearance of superconductivity with the change of oxygen content, were reasonably explained by chemical bond parameters. The results also showed that the Cu-O chains play a vital role in the transition from non-superconductors to superconductors, and the highest transition temperature occurred when the plane-chain reached a coupling state. (C) 1998 Elsevier Science Ltd. All rights reserved.

Characterization of propylene/ethylene copolymers sequentially polymerized with delta-TiCl3/Et2AlCl catalyst system

Morphological studies of a series of propylene/ethylene sequential polymers have been carried out by permanganic etching and transmission electron microscopy, as an aid to characterization, in conjunction with differential scanning calorimetry. The materials were synthesized using a titanium-based catalyst, with propylene and either ethylene or ethylene/propylene mixture introduced successively, with the aim of examining whether a proportion of block copolymer is obtained. These materials show a complicated phase structure which does not simply reflect polymerization time but varies greatly, especially in regard to the order of introduction of the monomers, and their morphology differs in a number of ways from that of typical commercial materials. Comparison of the materials, as synthesized and after extraction with heptane, suggests that there is a certain amount of material which can compatibilize polypropylene- and ethylene-rich phases, but it was not possible to decide whether it does in fact have block structure.

The crystal structure and supramolecular chain of [La(NO3)(3)(OH2)(2)(phen)]center dot 15-crown-5

[La(NO3)(3)(OH2)(2)(phen)]. 15-crown-5 is hexagonal, P6(5), with a = 10.955(2), c = 43.769(9) Angstrom, and D-calc = 1.668 g cm(-3) for Z = 6. In the complex, two nitrogen atoms (from phen) and eight oxygen atoms (six from three bidentate nitrate anions and two from water molecules) are coordinated to the central La(III) ion, forming a coordination polyhedron which is approximately a bicapped square antiprism. The coordinated water molecules donate hydrogen bonds to the oxygen atoms of the crown ether, forming polymeric hydrogen bonded chains which wrap helically along the unit cell direction c.

Study on ferrocene derivatives diffusion dynamics in polymer electrolyte by solid-state voltammetry

The diffusion rates of seven ferrocene derivatives have been estimated in polyelectrolyte PEG . LiClO4 by using non-steady-state chronoamperometry. The D-app of ferrocene derivatives increases with temperature, and the dependency of D-app on temperature obeys the Arrhenius equation. The D-app of ferrocene derivatives decreases with increasing size of electroactive species. The Delta D-app values of D-T>Tm and D-T T-m in the polyelectrolyte. On the other hand, the diffusion behaviour of ferrocene derivatives is qualitatively analyzed by using cyclic voltammetry. Copyright (C) 1996 Elsevier Science Ltd

Miscibility, crystallization, and morphology studies of thermosetting polyimide PMR-15/PEK-C blends

Miscibility, crystallization, and mechanical properties of blends of thermosetting polyimide PMR-15 and phenolphthalein poly(ether ketone) (PEK-C) were examined. With the exception of the 90/10 blend, which has two glass transition peaks, all the blends with PMR-15 less than 90 wt % are miscible in the amorphous state according to DMA results. Addition of PEK-C hindered significantly the crystallization of PMR-15, indicating that there must exist some kind of interaction between molecular chains of PMR-15 and those of PEK-C. The semi-IPN system of PMR-15/PEK-C blends exhibits good toughness. Two distinct microphases, interweaving at the phase boundaries, were found in the PMR-15/PEK-C 60/40 blend. The toughness effect of the blends is discussed in terms of the interface adhesion between the two distinct phases and the domain sizes of the phases. The relation between miscibility and toughness of the blends was investigated. (C) 1996 John Wiley & Sons, Inc.

Preparation and crystal structures of LaCl3(15-crown-5) and [LaCl2(phen)(H2O)(2)(mu-Cl)](2)center dot(15-crown-5)center dot MeCN

LaCl3(15-crown-5), I was prepared by the reaction of LaCl(3)nH(2)O with 15-crown-5 and bipy (2,2'-bipyridyl). [LaCl2(phen)(H2O)(2)(mu-Cl)](2) .(15-crown-5). MeCN, II, was crystallized from a mixture of LaC1(3) . nH(2)O, phen (1,10-phenanthroline) and 15-crown-5 in MeOH/MeCN, Crystal structures of these two complexes have been determined by X-ray methods. The La(III) ion in I is coordinated by three Cl anions and five oxygen atoms of a crown ether. The two metal ions in II are bridged by two Cl anions and the crown ligand is hydrogen-bonded to the coordinated water molecules to form polymeric... crown/cation/cation/crown... chains.

15个乙烯-乙烯基化合物共聚物的取代基参数

本文应用取代基参数(SCS)方法处了15个EV共聚物的~(12)C NMR谱.它们是:(1)乙烯-α-烯烃共聚物,即乙烯-丙烯共聚物.乙烯-丁烯-1共聚物,乙烯-4-甲基-1-戊烯共聚物,乙烯-己烯-1共聚物和乙烯-辛烯-1共聚物;(2)乙烯-含氧乙烯基共聚物,即乙烯-甲基丙烯酸N,N-二甲基胺乙酯共聚物,乙烯-丙烯酸甲酯共聚物.乙烯-丙烯酸共聚物,乙烯-乙酸乙烯酯,乙烯-乙烯醇,乙烯-氧化碳共聚物(ECO)(?)乙烯-卤代乙烯共聚物及其它EV共聚物,即乙烯-氯化乙烯共聚物(包含氯化聚乙烯),乙烯-溴化乙烯共聚物,乙烯-苯乙烯共聚物(包含氢化丁二烯-苯乙烯共聚物)和乙烯-丙烯腈共聚物、得到了15种取代基的SCS参数.

稀土冠醚配合物的研究XX．Schiff碱型双冠醚N，N’－对苯二甲亚基双（4’－氨基苯并－15－冠－5）稀土配合物的合成和性质

合成了一种Ｓｃｈｉｆｆ碱型双冠醚Ｎ，Ｎ’－对苯二甲亚基双（４’－氨基苯并－１５－冠－５）及其稀土硝酸盐的固体配合物，通过元素分析、摩尔电导、ＩＲ、ＵＶ、１ＨＮＭＲ和热分析等对其性质作了表征与比较。

STRUCTURE OF [LA(NO3)(3)(OH2)(2)(OHME)(BIPY)].15-CROWN-5

[La(NO3)(3)(OH2)(2)(OHMe)(bipy).15-crown-5 is monoclinic, P2(1)/n, with a = 11.239(6), b = 19.302(7), c = 14.458(8) Angstrom, beta = 92.47(5)degrees, and D-calc = 1.63 g cm(-3) for Z = 4. In the complex, two nitrogen atoms (from bipy) and nine oxygen atom

5，10，15，20－四（对－山嵛酸乙酯－α－氧代苯基）卟啉LB膜结构研究

５，１０，１５，２０－四（对－山嵛酸乙酯－α－氧代苯基）卟啉ＬＢ膜结构研究王海水，曾广赋，谷淑珍，席时权（中国科学院长春应用化学研究所长春１３００２２）利用ＬＢ膜技术将分子组装成有序的分子单层或多层体系，研究膜内分子间相互作用和分子的结构，对了解结构...