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Van Hove奇异性、非电声作用与HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导电性

张霞 , 苏希玉 , 侯芹英 , 侯艳丽

低温物理学报 doi:10.3969/j.issn.1000-3258.2008.03.011

考虑态密度的Van Hove奇异性和非电声作用,我们在BCS理论框架内研究了HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导转变温度和同位素效应.结果表明,当同时考虑Van Hove奇异性和非电声作用时,可以更好地解释HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导性质.

关键词: Van Hove奇异性 , 非电声作用 , 超导转变温度 , 同位素效应

Studies on the spin-Hamiltonian parameters of CuN(6) clusters and their tetragonal distortions due to Jahn-Teller effect for Cu(2+) in trigonal M(1-propyltetrazole)(6)(BF(4))(2) (M = Zn, Fe) crystals

Spectrochimica Acta Part a-Molecular and Biomolecular Spectroscopy

This paper reports the theoretical calculations for the anisotropic and isotropic spin-Hamiltonian parameters (g factors and the hyperfine structure constants) of tetragonal CuN(6) octahedral clusters due, respectively, to the static and dynamic Jahn-Teller effects for Cu(2+) ion in the trigonal M(=Zn, Fe) sites of M(1-propyltetrazole)(6)(BF(4))(2) crystals. The calculations are carried out using the high-order perturbation formulas based on a two-mechanism model, in which besides the contributions to spin-Hamiltonian parameters due to the crystal-field mechanism concerning the crystal-field excited states in the extensively used crystal-field theory, the contributions due to charge-transfer mechanism concerning the charge-transfer excited states (which are neglected in the crystal-field theory) are included. The calculated results are in reasonable agreement with the experimental values. From the calculations the tetragonal elongations Delta R= R(parallel to) R(perpendicular to) (where R(parallel to) and R(perpendicular to) denote the Cu-N distances parallel with and perpendicular to the C(4) axis) of CuN(6) octahedral clusters due to Jahn-Teller effect are obtained. The results are discussed. (C) 2010 Elsevier B.V. All rights reserved.

关键词: Electron paramagnetic resonance;Crystal- and ligand-field theory;Jahn-Teller effect;M(1-propyltetrazole)(6)(BF(4))(2) (M = Zn, Fe);Cu(2+);atomic screening constants;electron-paramagnetic-res;single-crystal;sulfate hexahydrate;charge-transfer;scf functions;epr;ions;field;copper(ii)

表面包覆法合成的LiN0.8Co0.2O2材料的结构表征

刘欣艳 , 赵煜娟 , 夏定国

功能材料

LiNi0.8Co0.2O2是锂离子电池界公认的最有希望取代商业化正极材料LiCoO2的新型正极材料之一.本文所研究的复合正极材料LiNi0.8Co0.2O2是由细小的晶粒构成的球形颗粒,单一相,属于R3m空间群.对复合材料LiNi0.8Co0.2O2的Co-K和Ni-K的XANES分析可知,在600~850℃范围温度对于钴元素的影响不明显,而对于镍元素的影响比较显著,随着Ni-K边位置向高能量移动LiNi0.8Co0.2O2正极材料的放电容量升高.复合材料LiNi0.8Co0.2O2和LiNiO2的Ni-K边XANES相似,表明少量钴的引入对晶体结构的改变不是太多,但是峰的强度较高和峰的位置向高能量移动,表明钴Co对Ni的局域结构进行了调制.

关键词: LiNi0.8Co0.2O2 , XANES , 正极材料 , 局域结构

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....

关键词:

DYNAMIC MECHANICAL BEHAVIOURS OF HIGH Mo AUSTENITIC STAINLESS STEEL DURING HOT DEFORMATION

XU Yourong , GU Qing , WANG Deying , Shanghai University of Science and Technology , Shanghai , ChinaGU Jufang , Q U Tiancai , Shanghai Iron and Steel Research Institute , Shanghai , China XU Yourong , Professor , Department of Materials Science , Shanghai University of Science and Technology , Shanghai 201800 , China

金属学报(英文版)

The dynamic mechanical behaviours of super low carbon high Mo austenitic stainless steel (00Cr20Nil8Mo6CuN)during hot deformation have been studied by using Formaster-Press hot working simulator. The hot deformation equation, as well as the relationship between peak strain, peak stress and Zener-Hollman parameter, together with the deformation activation energy have been resulted through the experiments.

关键词: hot deformation , null , null , null , null

精对苯二甲酸装置腐蚀原因分析及防蚀对策

孙占梅 , 吴雪芹

腐蚀科学与防护技术

本文介绍了高温醋酸和高温含溴对苯二甲酸中典型不锈钢设备的腐蚀状况以及316L、317L、Mo5Cu、00Cr20Ni18Mo6CuN、00Cr20Ni18Mo6N 5种材料在上述两种介质中的腐蚀原因和减缓腐蚀所采取的对策。

关键词: 醋酸 , null

双相钢在流动3.5%NaCI溶液中的磨损腐蚀

雍兴跃 , 刘景军 , 林玉珍 , 李焕文 , 韩俊媛 , 吴玖

腐蚀科学与防护技术 doi:10.3969/j.issn.1002-6495.1999.05.008

研究了0Cr25Ni6Mo3CuN双相钢在流动3.5%NaCl溶液中的磨损腐蚀行为,并对其磨损腐蚀的动力学过程进行了探讨.结果发现:双相钢在流动3.5%NaCl溶液中的磨损腐蚀速度随着流速的增大而增大,并存在一个使磨损腐蚀速度急剧上升的临界值.随着温度的升高,其磨损腐蚀明显加重.

关键词: 双相钢 , 流动 , 3.5% , NaCl溶液 , 磨损腐蚀 , 动力学过程

含取代茚基配体稀土金属有机化合物的合成、表征及催化性能

吴运军 , 张武 , 马怀柱

稀土 doi:10.3969/j.issn.1004-0277.2003.06.004

采用Schlenk技术,在干燥纯氩气保护下,用无水三氯化稀土LnCl3与2-苯基茚以1∶2的摩尔比在THF中反应,得到8种新配合物:(2-ph-Ind)2LnCl (A)[Ln=La(1), Pr(2), Nd(3), Sm(4), Gd(5), Dy(6), Yb(7), Y(8)].再用(A)和LiN(TMS)2在THF中反应,得到两种新的二(2-苯基茚)稀土有机配合物:(2-ph-Ind)2LnN(TMS)2 (B)[Ln=Y(1), Sm(2)].所有配合物都经元素分析、红外和质谱鉴定.配合物(B)在甲基丙烯酸甲酯(MMA)的聚合反应中显示出一定的活性.

关键词: 稀土合成 , 配合物 , 聚合 , 2-苯基茚

正极材料LiM0.9Ti0.1O2(M=Ni,Co)的合成及表征

贺慧 , 程璇 , 张颖 , 杨勇

功能材料

利用溶胶-凝胶预处理固相方法合成了锂离子电池正极材料LiM0.9Ti0.1O2(M=Ni,Co),通过XRD对合成的材料进行结构分析,并将其组装成电池进行了电化学测试,对两种材料LiN0.9Ti0.1和LiCo0.9Ti0.1进行了比较.结果发现,LiCo0.9Ti0.1O2的结构和性能要好于LiNi0.9Ti0.1O2,根据实验结果对其原因进行了初步的分析.

关键词: 锂离子电池 , 正极材料 , 电化学性能

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