J.L. Li 1
,
2)
,
K.F. Wong 3) and G.H. Zhu 3) 1) Fushun Petroleum Institute
,
Fushun 113001
,
China 2) State Key Laboratory for Corrosion and Protection of Metal
,
Institute of Corrosion and Protection of Metals
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China 3) Zhejiang University
,
Hangzhou 310027
,
China
金属学报(英文版)
This paper integrates the characteristic of structure design and manufacture and maintenance for Chinese flat steel band wound pressure vessel(UCWPV) with the problems existing in current in service high temperature and pressure vessel exposed to hydrogen. In view of economy and safety it is suggested that it be practicable for UCWPV to act as reactors for platreating, hydrogenating, and catforming. UCWPV has not only potential advantages, but also removes shortages present in in-service reactors for hydrogen.
关键词:
design
,
null
,
null
Journal of Magnetism and Magnetic Materials
The electron paramagnetic resonance g factors g(parallel to) and g(perpendicular to) for the trigonal Er3+-V-K centers (where V-K denotes K+ vacancy) in KMF3 (M = Mg and Zn) are theoretically investigated from the perturbation formulas of the g factors for a 4f(11) ion in trigonal symmetry. In these formulas, the contributions to the g factors from the second-order perturbation terms and the admixture of various energy levels are taken into account. In the above trigonal centers, the impurity Er3+ resides in the octahedral M2+ site of both crystals, associated with one V-K in the C-3-axis due to charge compensation. By analyzing their g factors, we find that the impurity Er3+ in both centers would move towards the V-K by an amount DeltaZ along the C-3-axis due to electrostatic attraction. The calculated g factors for the Er3+ centers based on the above displacements DeltaZ show good agreement with the observed values. The validity of the results is discussed. (C) 2004 Elsevier B.V. All rights reserved.
关键词:
electron paramagnetic resonance (EPR);defects and impurities;crystal-field and spin hamiltonians;Er3+;KMF3;(M = Mg and Zn);crystal-field;superposition-model;perovskite kmgf3;conversion;parameters;fluorides;kznf3
Physica B-Condensed Matter
The spin-Hamiltonian parameters (g factors g(parallel to), g(perpendicular to) and hyperfine structure constants (161)A(parallel to), (161)A(perpendicular to), (163)A(parallel to), (163)A(perpendicular to)) for Dy(3+) at the tetragonal H(f)(4+) site of H(f)SiO(4) crystal are calculated from the diagonalization (of energy matrix) method. In the method, we add the Zeeman (or magnetic) and hyperfine interaction terms to the conventional Hamiltonian used in the calculations of crystal-field energy levels. The 66 X 66 energy matrix concerning the new Hamiltonian is established by considering the ground multiplet (6)H(15/2) and the first to fifth excited multiplets (6)H(J) (where J=13/2, 11/2,9/2, 7/2 and 5/2), and the crystal-field parameters in the energy matrix are calculated from the superposition model. From the calculations, the spin-Hamiltonian parameters of H(f)SiO(4):Dy(3+) are explained reasonably and the signs of hyperfine structure constants for (161)Dy(3+) and (161)Dy(3+) isotopes in H(f)SiO(4) are suggested. The results are discussed. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Electron paramagnetic resonance;Crystal-field theory;Point defect;Dy(3+);H(f)SiO(4);superposition-model analysis;single-crystals;paramagnetic-resonance;structure silicates;zircon;growth;hafnon;field;epr;er3
钱华
,
刘大斌
,
王亮
应用化学
doi:10.3969/j.issn.1000-0518.2009.09.018
以间苯三酚为起始原料,通过醚化反应、碘化反应、Pechmann反应、偶联反应、水解反应和脱羧反应合成了目标产物4-甲氧基-7H-呋喃[3,2-g][1]苯并吡喃-7-酮. 利用红外光谱、质谱、核磁共振测试技术对各化合物的结构进行了表征. 优化了醚化反应和碘化反应的工艺条件,并探索了通过选择性碘化反应、Pechmann反应和偶联反应来合成目标化合物的可行性. 反应均在常压下进行,反应条件温和,催化剂价廉,后处理相对简单,目标产物的总收率为12%.
关键词:
呋喃香豆素
,
香柑内酯
,
间苯三酚
,
全合成
崔焱
,
林艳
,
谢刚
,
杨大锦
黄金
doi:10.11792/hj20140412
采用循环伏安法和线性扫描技术等电化学研究方法，系统研究了电解液体系中各阴阳离子对锑电沉积过程的影响。通过测定Sb3＋、NH4＋、F-、SO2-4及草酸等组分不同质量浓度下体系的循环伏安曲线、稳态极化曲线及塔菲尔曲线，分析了各离子在电解过程中的电化学行为及作用，确定了H2 SO4-NH4 F-SbF3电解液体系合适的成分为Sb3＋90～120 g／L、NH4＋50 g／L、F-80 g／L、H2 SO4360 g／L、H2 C2 O44～10 g／L。在此电解液体系下进行了粗锑的电解精炼试验，阴极锑纯度为99．9436％，达到国标1号精锑标准，阴极电流效率为97．60％。
关键词:
锑
,
电解精炼
,
H2 SO4 -NH4 F-SbF3体系
吴振雄
,
何小玲
,
周海涛
,
涂衡
,
岳银超
,
张昌龙
,
胡章贵
人工晶体学报
采用水热法,探索了 K4Gd2(CO3)3F4晶体的析晶条件,诸如生长原料及配比、生长温度、生长周期等,并成功生长了毫米级的透明单晶.对生长的晶体进行了XRD、UV-Vis-NIR、SHG等测试,结果表明,K4Gd2( CO3)3F4晶体在380～2000 nm波段的透过率超过80％,紫外吸收截止边低于200nm；其二阶非线性光学效应约为KDP的3.5倍.
关键词:
非线性光学晶体
,
K4Gd2(CO3)3F4晶体
,
水热法
International Journal of Hydrogen Energy
A highly active photocatalyst based on g-C(3)N(4) coated SrTiO(3) has been synthesized simply by decomposing urea in the presence of SrTiO(3) at 400 degrees C. The catalyst demonstrates a high H(2) production rate similar to 440 mu mol h(-1)/g catalyst in aqueous solution under visible light irradiation, which is much higher than conventional anion doped SrTiO(3) or physical mixtures of g-C(3)N(4) and SrTiO(3). The improved photocatalytic activity can be ascribed to the close interfacial connections between g-C(3)N(4) and SrTiO(3) where photo-generated electron and holes are effectively separated. The newly synthesized catalyst also exhibited a stable performance in the repeated experiments. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
关键词:
Carbon nitride;Photocatalyst;Visible light;SrTiO(3);tio2 nanotube photocatalyst;hydrogen-production;water;generation;oxynitride
胡义华
,
刘美希
,
周金运
,
王小涓
,
陈丽
,
杨新
,
杨世和
量子电子学报
doi:10.3969/j.issn.1007-5461.2000.02.011
利用共振光电离技术和飞行时间质谱技术,观察到了复合物p-C6H4F2…NH3(ND3)的共振双光子电离光谱。光谱分析表明,复合物分子间的伸缩振动频率为86.4～cm-1; 由复合物的光解离机理以及伸缩模的失谐参数与键能的关系,获得了复合物电子激发态S1和基态S0的键能信息。Ab initio 计算表明,p-C6H4F2…NH3(ND3) 复合物的几何结构是:NH3分子中的N原子位于垂直于p-C6H4F2分子环面的对称轴(Z轴)上,距环面的高度为0.352～nm; NH3的C3轴与p-C6H4F2的对称轴夹角是52.5°,且一个氢原子朝向环面;NH3可绕p-C6H4F2分子的Z轴近似的自由转动。键能计算值和预计存在的内转动与实验吻合。
关键词:
共振多光子电离光谱
,
分子间的振动
,
范德瓦尔斯键能
