L.I.Mikhoduj (The E. O. Paton Electric Welding Institute
,
NAS of Ukraine
,
Kiev
,
Ukraine)
金属学报(英文版)
Composition and service properties of high - strength low-alloyed steels with 590-980 MPa yield strength,which find an application in Russia, Belorus,Ukraine and other countries of the former USSR in manufacture of welded structures of a powerful mining and transport machinery, are given. Electrodes and wires for main processes of arc welding of these steels have been devel- oped on the basis of a rational use of different systems of alloying (08KhN2GM,08KhNG2M, and also economical systems of type 10G25, ect. ). Main approaches to the technological provess- es of manufacture of structures of high - strength steels are formulated.They are mainly directed to the weakening of de offect of the factors which contribute to a delayed fracture of joints (diffusive hydrogen,unfavourable rates of cooling,level of residual stresses). When there are no stress concentrators (and at a low level of residual stresses) the welded joints of these steels have a good resistance to fatigue and brittle fractures.As a rule, they are prevented with the help of the known approaches.It is shown that in addition to them and due to a proper selection of conditions of welding the life of welded joints of the high - strength steels can be 1. 2 - 1. 4 times in- creased.
关键词:
high-strength steel
,
null
,
null
,
null
戴沛霞
,
曹文秀
,
葛红光
,
王栋
人工晶体学报
水热合成了镍(Ⅱ)-2-萘胺-1-磺酸-邻菲哕啉三元配合物[Ni(nas)2 (phen)2],并用红外、元素分析、热重、固体紫外和X-射线单晶衍射法对配合物的晶体结构进行了表征.结果表明,该配合物属于四方晶系,空间群P41212,晶胞参数a=1.24321(4) nm,b=1.24321(4) nm,c =2.45032(16) nm,α=90.00°,β=90.00°,γ=90.00°,V=3.7871(3) nm3.
关键词:
2-萘胺-1-磺酸
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邻菲哕啉
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配合物
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晶体结构
Anti-Corrosion Methods and Materials
Purpose - The objective of the present work was to study the influence of chemical compositions of five naphthenic acids (NAs) extracted from Liaohe crude oil on their corrosivity. Design/methodology/approach - Fourier-transform infrared spectrometry and electron impact mass spectrometry were used to characterize the chemical structures and compositions if five NAs. The corrosivities of the NAs were assessed by stagnant NA corrosion (NAC) tests. An attempt was made to identify any correlation between the chemical composition of the NAs and their corrosiveness. Findings - The acidic species in all five NA samples were saturated aliphatic and naphthenic acids and the amount of aromatic and unsaturated acids was negligible. A relationship between the carboxylic acid distribution and the molecular weight was obtained. Most of the carboxylic acids in five NAs contained 0-3 ring structures. NAs with lower molecular weight and fewer ring structures usually were more corrosive. Originality/value - The findings have important implications for assessing the corrosivity of acidic crude oils from various resources.
关键词:
acids;corrosion;mass spectrometry;oils;chromatography-mass spectrometry;erosion-corrosion;high-temperature;crude-oil;steels;q235
Journal of Magnetism and Magnetic Materials
First-principles full-potential linearized augmented plane-wave method is used to investigate the electronic structure and magnetic properties of hypothetical zinc-blende and rocksalt LiS, NaS and KS. We find that all the compounds except rocksalt LiS exhibit half-metallic ferromagnetism with an integer magnetic moment of 1.00 mu(B) per formula unit. The ferromagnetism results from the spin-polarization of p states of anion S. Total energies calculations indicate the rocksalt phase is lower in energy than the zinc-blende one. The total energy differences are about 0.38, 0.36 and 0.32 eV per formula unit for LiS, NaS and KS, respectively. Meanwhile, it is shown that rocksalt NaS and KS have the half-metallic gaps of 0.22 and 0.41 eV, respectively, and the half-metallic gaps are 0.03, 0.46 and 0.65 eV for zinc-blende LiS, NaS and KS, respectively. We also find the half-metallicity is robust against the lattice contraction up to 7% and 13% for rocksalt NaS and KS, respectively. Although rocksalt LiS is nonmagnetic and metallic at the equilibrium lattice constant, it shows half-metallic ferromagnetism when the lattice constant is larger than 5.40 angstrom. (C) 2011 Elsevier B.V. All rights reserved.
关键词:
Half-metallicity;Density of state;First-principles calculation;molecular-beam epitaxy
赵中伟
,
陈爱良
,
孙培梅
,
陈星宇
,
霍广生
,
李洪桂
中国有色金属学报
将"活性硫化镍法"所用的除铜试剂"硫化镍"视为先导化合物,按电子等排原理,通过分子修饰进行类型衍化,修饰阴离子,以一种新设计的含硫化学结构取代S2-,得到的新型除铜剂为NAS和硫化镍混合物.结果表明:当NAS纯度α≥73%(NAS在混合物中所占比例)、除铜剂用量为理论量的1.2倍、溶液pH值为4.0、反应温度为60℃时反应80 min后,采用新型除铜剂从镍电解阳极液中除铜,除铜后溶液中的铜浓度c(Cu2+)可降至1.57×10-5mol/L,除铜渣中铜镍质量比不小于25,远优于工业生产的要求(c(Cu2+)≤1.57×10-5mol/L,渣中铜镍质量比不小于15);NAS在自然条件下放置62 d后,其除铜效果仍然能够满足生产要求,且NAS在除铜过程中没有引入有害离子进入溶液.
关键词:
镍电解阳极液
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除铜:电子等排原理
X. Liu*
,
W.H. Tian
,
null
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null
,
null
,
null
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null
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null
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null
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null
,
null
,
null
,
null
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null
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null
,
null
金属学报(英文版)
Chemical delithiated LixCoO2 (x=1, 0.7, 0.66 and 0.57) has been synthesized by using a strong oxidant, NaS2O8. The structure investigations indicate that all the samples remain with hexagonal cells, which have expansion of c axis during Li extraction. Transmission electron microscopy (TEM) observations revealed the presence of superstructures arising from intercalated Li-ordering corresponding to first-principle calculations. The measurements of the physical properties are also influenced by Li concentration.
关键词:
LixCoO2
,
脱锂
,
锂离子有序
王家斌
,
王啸
,
李建华
,
吕海霞
,
林旭聪
,
谢增鸿
,
张其清
色谱
doi:10.3724/SP.J.1123.2011.01222
采用N-丙烯酰琥珀酰亚胺(NAS)为基质单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,原位聚合制备聚(NAS-co-EDMA)毛细管整体柱,并通过化学键合法将自合成的纤维素-三(4-甲基苯甲酸酯)(CTMB)共价键合到整体柱上,制备用于快速手性分离的纤维素键合型手性整体柱.优化了整体柱制备和衍生化条件；通过对固定相红外光谱和电渗流表征,证实CTMB已键合到整体柱上.探讨了流动相中乙酸浓度、甲醇含量等条件对整体柱手性分离的影响.使用该整体柱,分别在1.2 min内实现了5种对映体(苯丙氨酸、酪氨酸、色氨酸、普洛萘尔、苯乙醇)的毛细管电色谱快速手性分离,分离度可达1.31.
关键词:
纤维素-三(4-甲基苯甲酸酯)
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共价键合
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手性毛细管整体柱
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毛细管电色谱
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快速手性分离
