HAN Gui-hong
,
JIANG Tao
,
ZHANG Yuan-bo
,
HUANG Yan-fang
,
LI Guang-hui
钢铁研究学报(英文版)
By means of isothermal oxidation and chemical analysis, great importance was attached to the parameters that made effects on the oxidation degree of vanadium, titanium-bearing magnetite pellet in high-temperature processing (1073-1323 K). Based on the experimental data, oxidation kinetics of pellet was analyzed according to shrinking unreacted-core model subsequently. Experiment results display that the oxidation degree of pellet increases with increasing of oxidation time, oxidation temperature and oxygen content, as well as shrinking of pellet diameter. Under the condition of oxidation time 20 min, oxidation temperature 1223 K, oxygen content 15%, and pellet diameter 12 mm, oxidation degree of pellet reaches 92.92%. The analysis of oxidation kinetics indicates that oxidation process of pellet is controlled by chemical reaction with activation energy 68.64 kJ/mol at a relatively lower temperature (1073-1173 K). Oxidation process of pellet is mixed-controlled by chemistry reaction and diffusion with activation energy 39.66 kJ/mol in the temperature range of 1173-1273 K. When oxidation temperature is higher than 1273 K, the limited link of oxidation reaction is the diffusion control with the activation energy 20.85 kJ/mol. These results can serve as a reference to the production of vanadium, titanium-bearing magnetite pellet.
关键词:
vanadium
,
titanium-bearing magnetite
,
oxidation degree
,
pellet
,
shrinking unreacted-core model
,
oxidation kinetics
白宣羽
,
汪渊
,
徐可为
稀有金属材料与工程
采用磁控溅射方法在Si(111)基片上沉积Cu-Zr/ZrN薄膜体系作为扩散阻挡层.通过比较Cu-Zr/ZrN薄膜体系和三元非晶(Mo,Ta,W)-Si-N的电阻率,同时比较Cu-Zr/ZrN薄膜体系和Ta,YaN的硬度,说明作为扩散阻挡层的材料的选取,应从整体性能上考虑,而不能仅仅考虑热稳定性等单一指标.
关键词:
非晶
,
电阻率
,
纳米压入
,
硬度
许传龙
,
王式民
工程热物理学报
在加压密相气力输送实验装置上获得了不同操作条件下煤粉颗粒静电波动信号,并用Hilbert-Huang变换、功率谱进行分析.结果表明:随着表观速度的增加,静电波动信号主峰值的频率增大;静电波动信号希尔伯特-黄变换(Hilbert-Huang)揭示了气固两相流静电信号的非线性和非平稳特征,随气固两相流颗粒相浓度降低和颗粒及表观速度增加,静电波动信号特征尺度由高尺度(低频)向低尺度(高频)转移.多尺度分析有助于认识气固两相流动形态及其转变规律.
关键词:
颗粒静电
,
静电传感器
,
气-固两相流
,
Hilbert-Huang变换
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:
Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
Monocrystalline copper samples with [001] and [221] orientations were subjected to shock/recovery experiments at 30 and 57 GPa and 90 K. The slip system activity and the microstructural evolution were investigated. Different defect structures, including dislocations, stacking faults, twins, microbands, and recrystallized grains were observed in the specimens. The residual microstructures were dependent on crystalline orientation and pressure. The differences with crystalline orientations are most likely due to different resolved shear stresses on specific crystalline planes. The geometric relationships between the shock propagation direction and crystalline orientation are presented under uniaxial strain. It is shown that the [2 2 11 orientation, by virtue of having fewer highly activated slip systems, exhibits greater concentration of deformation with more intense shear on the primary system. This, in turn leads to greater local temperature rise and full recrystallization, in spite of the thermodynamic residual temperature of similar to 500 K and rapid cooling (within 20 s) to ambient temperature. The profuse observation of microbands is interpreted in terms of the mechanism proposed by Huang and Gray [J.C. Huang, G.T. Gray III, Acta Metallurgica 37 (1989) 3335-3347]. (C) 2009 Elsevier B.V. All rights reserved.
关键词:
Shock compression;Shock loading;Slip bands;Microtwins;Microbands;strain rate history;single-crystals;grain-size;constitutive;description;plastic-deformation;mechanical response;deformed metals;loaded nickel;substructure;recrystallization
Physical Review B
An elastic Ising model for CoMnO(6) chain is proposed to explain the ferroelectricity induced by collinear magnetic order in Ca(3)CoMnO(6), and then a mean-field theory with interchain spin interactions based on this model is developed. With inclusion of the dynamics of polarization domains at finite temperature, we address the rationality of our theory by the good agreement of the calculated electric polarization and dielectric susceptibility with the reported data on Ca(3)Co(2-x)Mn(x)O(6) (x approximate to 0.96) [Y. J. Choi, H. T. Yi, S. Lee, Q. Huang, V. Kiryukhin, and S.-W. Cheong, Phys. Rev. Lett. 100, 047601 (2008)], a typical diatomic Ising spin chain system, while the predicted magnetic susceptibility shows some difference from experiment, the reason of which is discussed.
关键词:
calcium compounds;cobalt compounds;dielectric polarisation;ferroelectricity;Ising model;magnetic susceptibility;multiferroics;optical susceptibility;one-dimensional oxides;magnetic-properties;multiferroics;ca3co1+xmn1-xo6
Physica B-Condensed Matter
Polycrystalline La0.5Lu0.2Sr0.3MnO3 samples prepared by thermal decomposition are investigated by means of electron diffraction and high-resolution transmission electron microscopy. Besides rhombohedral La0.7Sr0.3MnO3 phase (R-phase) and hexagonal LuMnO3 phase (H-phase) reported by Huang, unexpectedly, an orthorhombic lattice (O-phase) with space group Pnma is observed in the interior of R-phase grain. The lattice parameters of the orthorhombic unit cell are a(o) = 5.44 angstrom, b(o) = 7.65 angstrom and c(o) = 5.48 angstrom The formation of O-phase results from a(-)b(+)a(-) type orthorhombic distortion of MnO6 octahedra induced by partial substitution of Lu3+ for La3+. Meanwhile, based on image simulation of the interface between R and O-phases, the atomic bonding on the interface is particularly discussed. (c) 2005 Elsevier B.V. All rights reserved.
关键词:
orthorhombic lattice;octahedral;substitution;atomic bonding;la0.7-xluxsr0.3mno3 perovskites;transport-properties;magnetoresistance;films
