材料期刊网，材料期刊，材料类期刊，材料期刊投稿

A new technique, powder compact foaming process for the production of aluminum foams has been studied in this article. According to this method, the aluminum powder is mixed with a powder foaming agent (TiH2). Subsequent to mixing, the powder blend is hot compacted to obtain a dense semi-finished product. Upon heating to temperatures within the range of the melting point, the foaming agent decomposes to evolve gas and the semi-finished product expands into a porous cellular aluminum. Foaming process is the key in this method. Based on experiments, the foaming characteris- tics were mainly analyzed and discussed. Experiments show that the aluminum-foam with closed pores and a uniform cell structure of high porosity can be obtained using this method by adjusting the foaming parameters: the content of foaming agent and foaming temperature.

关键词: aluminum foams , null , null

马普协会煤化所和F. Schüth教授的研究活动

陆安慧

新型炭材料 doi:10.3969/j.issn.1007-8827.2003.04.014

关键词:

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

F-12纤维的吸湿行为

阳建红 , 董进辉 , 李海斌 , 石强 , 郭明映

复合材料学报

在60℃、80℃相对湿度90%环境条件下对F-12纤维进行了湿热老化实验,研究了长时间老化时纤维吸湿规律.通过ATR-FTIR光谱分析了湿热老化后水对F-12纤维化学结构的影响以及水在纤维中可能存在的方式,探讨了吸湿机制,实验研究了纤维单丝拉伸强度的变化,并采用SEM观察了纤维表面及拉伸断口形貌.结果表明:F-12纤维长时间的吸湿属于2阶段吸湿,吸湿初期符合Fick第二定律,后期偏离,吸湿2500 h后仍没达到平衡;水分子对F-12纤维的化学结构没有造成明显的破坏,老化2500 h后F-12纤维表面变得粗糙,出现了一些沟槽,老化后期断口呈现出脆性与原纤化复合的特征;拉伸断裂强度并非持续减小,而是在起伏波动中减小.

关键词: F-12纤维 , 吸湿规律 , ATR-FTIR , SEM , 吸湿机制 , 拉伸强度

镧系配合物f-f跃迁光谱的分析应用

杨武 , 陈淼 , 康经武 , 欧庆瑜 , 康敬万 , 高锦章

冶金分析 doi:10.3969/j.issn.1000-7571.1999.05.013

对f-f跃迁光谱在分析化学中的应用进展进行了简要的总结,详细地介绍了根据超灵敏跃迁强度变化规律测定溶液中镧系配合物的组成、形成常数及测定混合稀土中单一稀土的原理和方法.

关键词: f-f跃迁光谱 , 镧系元素配合物 , 组成测定 , 形成常数 , 综述

金红石TiO₂晶体中F和F⁺心电子结构及其吸收光谱研究

陈军 , 林理彬 , 卢铁城

无机材料学报

本文运用嵌入原子簇的电荷自治离散变分方法（SCC－DVM－Xα方法）分别对TIO₂晶体中F和F+心的能级结构进行了计算，得到了F和F⁺心的光学吸收跃迁模式，其跃迁能量分别是0.98、1.78eV.我们认为，经还原后的TiO2晶体，在光吸收实验中测到的1．2μm（1.02eV）、760um（1.75eV）两个峰分别是由于还原过程中形成的F和F⁺心的吸收峰，并存在着F→F⁺的转型过程．

关键词: F , F⁺ center , energy level , transition energy

金红石TiO2晶体中F和F+心电子结构及其吸收光谱研究

陈军 , 林理彬 , 卢铁城

无机材料学报 doi:10.3321/j.issn:1000-324X.1999.03.006

本文运用嵌入原子簇的电荷自洽离散变分方法(SCC-DVM-Xα方法)分别对TiO2晶体中F和F+心的能级结构进行了计算,得到了F和F+心的光学吸收跃迁模式,其跃迁能量分别是0.98、1.78eV.我们认为,经还原后的TiO2晶体,在光吸收实验中测到的1.2μm(1.02eV)、760nm(1.75eV)两个峰分别是由于还原过程中形成的F和F+心的吸收峰, 并存在着F→F+的转型过程.

关键词: F , F+心 , 能级结构 , 跃迁能量