F. Yan
材料科学技术（英文）
A pure Cu (99.995 wt%) has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding have been quantitatively characterized by transmission electron microscopy (TEM) assisted by convergent beam electron diffraction (CBED) analysis. Microstructures originated from dislocation slip inside or outside the shear bands are characterized by low angle boundaries (<15°) that are spaced in the nanometer scale, whereas most deformation twins are deviated from the perfect Σ3 coincidence (60°/<111>) up to the maximum angle of 9°. The quantitative structural characteristics are compared with those in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of the flow stress-structural parameter relationship.
关键词:
Quantitative structural characterization
F. Yan
材料科学技术（英文）
A pure Cu (99.995 wt%) has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding have been quantitatively characterized by transmission electron microscopy (TEM) assisted by convergent beam electron diffraction (CBED) analysis. Microstructures originated from dislocation slip inside or outside the shear bands are characterized by low angle boundaries (<15°) that are spaced in the nanometer scale, whereas most deformation twins are deviated from the perfect Σ3 coincidence (60°/<111>) up to the maximum angle of 9°. The quantitative structural characteristics are compared with those in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of the flow stress-structural parameter relationship.
关键词:
Quantitative structural characterization
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
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
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
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
