材料期刊网

Kinetics of Voluminal Reduction of Chromium Ore Fines Containing Coal by Microwave Heating

CHEN Jin , WANG Shebin , ZHANG Meng , LIU Jinying , ZHOU Jianxiong

钢铁研究学报(英文版)

The kinetics of voluminal reduction of chromium ore fines containing coal (COFCC) by microwave heating was studied. When the molar ratio of carbon to oxygen was 084 and that of CaO to SiO2 was 039 in COFCC, the temperaturerising rate of COFCC by microwave heating was 625 ℃/min, 6875 ℃/min, 7059 ℃/min, and 7222 ℃/min at 1 000 ℃, 1 100 ℃, 1 200 ℃, and 1 300 ℃, respectively. The results show that the voluminal reduction of COFCC by microwave heating at solidsolid phase is first order reaction, with the apparent activation energy of 51480 kJ/mol. The limiting step of reaction rate for the overall reaction is the mass transfer of CO in the reduced product layer between dielectric particles of chromium ore and coal.

关键词: kinetics;microwave heating;voluminal reduction;chromium ore fine

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

SHE法制备高孔隙度TiNi合金

张小明 , 殷为宏 , 王学成

稀有金属材料与工程

使用Ti和Ni的元素粉末,用自蔓延高温合成(SHS)技术制备了等原子的多孔TiNi形状记忆合金,获得的多孔样品具有规整的外形和一定的尺度及较好的孔洞连通性.测量了样品的表观密度、最大孔径和透气性能.用SEM和XRD分析了样品的孔洞特征、元素分布及相组成.结果表明,SHS法制备高孔隙度TiNi合金,产物孔隙度高达50%以上,元素化合充分、成份均匀,且工艺过程短、节省能源,是一种比较理想的制备方法.

关键词: SHS , 多孔材料 , TiNi合金

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Effect of interstitial hydrogen on cohesive strength of Al grain boundary with Mg segregation

材料科学技术（英文）

The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles

Effect of Interstitial Hydrogen on Cohesive Strength of Al Grain Boundary with Mg Segregation

Xiaoguang LIU , Xiaowei WANG

材料科学技术（英文）

The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: Hydrogen , null , null

Sliding wear behaviour of SiC particle reinforced 2024 aluminium alloy composites

Materials Science and Technology

Sliding wear tests on SiC particle reinforced 2024 aluminium alloy composites fabricated by a powder metallurgy technique were carried out, and she effects of SiC particle content, size, and the wear load on the wear properties of the composites were systematically investigated. It was found that the weal resistance of the composites was about two orders of magnitude superior to that of the unreinforced matrix alloy, and increased with increasing SiC particle content and size. Under the conditions of sliding wear used, the effect of SiC particle size on the wear resistance was more significant than that of particle content. (C) 1996 The Institute of Materials.

关键词: matrix composites;tribological properties;fabrication

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:

BiNbO_4纳米棒的制备及光催化性能研究

赵洁 , 姚秉华 , 冯逸晨

功能材料

采用共沉淀法制备BiNbO4纳米棒。利用X射线粉末衍射仪（XRD）、透射电镜（TEM）、紫外-可见漫反射光谱（UV-Vis DRS）和热重分析（TG/DTA）对其结构、形貌和性质进行表征,并通过紫外-可见分光光度计分析BiNbO4纳米棒光降解罗丹明B来研究其光催化活性。结果表明以五氧化二铌和五水硝酸铋为原料制备得到正交相结构的BiNbO4纳米棒;BiN-bO4纳米棒具有较高的光催化活性,在紫外光下,pH值=3.05,催化剂用量为2g/L时能够有效地降解罗丹明B,降解率受到光源、催化剂浓度和溶液pH值的影响较大。

关键词: 共沉淀法 , BiNbO4纳米棒 , 光催化

基于稀疏随机投影的SIFT医学图像配准算法

杨飒 , 郑志硕

量子电子学报 doi:10.3969/j.issn.1007-5461.2015.03.005

针对尺度不变特征变换(Scale-invariant feature transform,SIFT)算法在关键点特征描述向量阶段计算复杂并且维数较高的现象,提出了一种基于压缩感知理论的SIFT算法.通过压缩感知理论的稀疏特征表示方法,对SIFT关键点特征向量进行提取,将高维梯度导数向量降到低维稀疏特征向量,降低了关键点描述向量维度.采用欧式距离作为关键点的相似性度量, Best-Bin-First(BBF)数据结构避免穷举,使数据的运算量大为减少.实验结果表明,新算法对存在仿射变换的医学图像配准性能优于传统SIFT算法,与当前改进型的SIFT算法相比,本文算法的实时性明显增强.

关键词: 图像处理 , 图像配准 , 尺度不变特征变换 , 特征提取 , 稀疏随机投影