LIU Guoquan Department of Materials Science and Engineering
,
University of Science and Technology Beijing
,
100083
,
China.
材料科学技术（英文）
Quantitative analysis of populations having a geometric structure,which has developed into a special scientific subject called microstructology or stereology,is of great importance to the characterization and evaluation of microstructures and their evolution in various processes.This paper, besides a brief discussion on those topics such as the recent developments of computer assisted image analysis,mathematical morphology,and fractal analysis,will mainly focus on the scope,fundamen- tals,present status,and perspectives of classical stereology.Several case examples of its application to materials science will also be given.
关键词:
stereology
,
null
,
null
,
null
Douxing LI and Hengqiang YE (Laboratory of Atomic imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
110015
,
China)
材料科学技术（英文）
The present paper summarizes the current status of high resolution electron microscopy (HREM)and the applications of HREM to materials science and condensed matter physics. This review recounts the latest development of high resolution electron microscope, progress of HREM and the applications of HREM, including the crystal structure determination of microcrystalline materials and characterization of the local structure of the defects and nanostructured materials as well as qualitative and quantitative analysis of the grain boundaries, interfaces and interfacial reactions in the advanced materials by means of HREM in combination with electron diffraction,subnanometer level analysis, image simulation and image processing.
关键词:
梁宏伟
,
桑革
,
王清
,
李嵘
,
沈崇雨
稀有金属
doi:10.3969/j.issn.0258-7076.2003.02.010
制备了8种金属含量不同的Pt-Ir/C/PTFE疏水性催化剂,采用这些催化剂进行了H-D同位素气液对流、气汽并流交换实验,初步考察了温度、压力、氢气流速对催化活性的影响. 实验表明,Ir的加入能够提高疏水催化剂的催化活性,当Ir在二元金属中的含量为25%时,催化剂的催化活性得到提高.
关键词:
催化化学
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疏水催化剂
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氢同位素交换
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氘
高健
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康健
,
吴学玲
,
徐競
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李邦梅
,
邱冠周
中国有色金属学报
以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.
关键词:
L.ferriphilum YSK菌株
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Fe2+
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生长活性
N.V.Ch
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ra Shekar
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P.Ch.Sahu
,
K.Govinda Rajan
材料科学技术（英文）
Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored.
关键词:
Laser heating
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null
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null
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null
International Journal of Hydrogen Energy
A systematic investigation on the hydrogen storage properties of Li-Mg-N-H materials with various compositions was performed. Li-Mg-N-H hydrogen storage materials were prepared by mechanically milling LiNH2/MgH2 mixtures with initial molar ratios ranging from 1.5:1 to 3: 1, followed by de/rehydriding at 200 degrees C. It was found that the hydrogen storage capacity of the system was highly dependent on the initial phase ratio of the LiNH2/MgH2 mixture. An optimum hydrogen capacity of about 5 wt% was achieved in the 2.15:1 LiNH2/MgH2 mixture. Different carbon materials, such as the single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes, graphite and activated carbon, were used as additive to improve the hydrogen storage performance. It was found that the dehydriding kinetics of the Li-Mg-N-H material could be markedly improved by adding a small amount of SWNTs, especially in the as-prepared state. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
关键词:
hydrogen storage;dehydriding kinetics;carbon nanotubes;arc-discharge method;system;microstructure;desorption;absorption;behaviors;property;imides
王华林
,
方大庆
,
史铁钧
,
翟林峰
,
王继植
应用化学
doi:10.3969/j.issn.1000-0518.2005.06.017
在催化剂辛酸亚锡(ZnOct2)的作用下,合成了聚D,L-乳酸(PDLLA). 研究了催化剂用量、反应温度和时间对PDLLA分子量的影响. 得到的最佳合成条件为:ZnOct2质量分数为0.5%,聚合温度为170 ℃,聚合时间为7 h. 考察了PDLLA在生理盐水中的降解情况,采用XRD对降解产物进行了表征. 结果表明,PDLLA降解时,先生成不溶于生理盐水的低聚物,然后生成可溶性的低聚物,并有(D,L)丙交酯形成,质量损失迅速增加,最终降解完全.
关键词:
聚(D
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L)-乳酸
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D
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L-丙交酯
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生理盐水
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降解性
D.Han
,
S.R.Qiao
,
M.Li
,
J.T.Hou
,
X.J.Wu
金属学报(英文版)
The differences of tension-tension fatigue and tensile creep characters of 2D-C/SiC and 3D-C/SiC composites have been scrutinized to meet the engineering needs. Experiments of tension-tension fatigue and tensile creep are carried out under vacuum high temperature condition. All of the high temperature fatigue curves are flat; the fatigue curves of the 2D-C/SiC are flatter and even parallel to the horizontal axis. While the tension-tension fatigue limit of the 3D-C/SiC is higher than that of the 2D-C/SiC, the fiber pullout length of the fatigue fracture surface of the 3D-C/SiC is longer than that of the 2D-C/SiC, and fracture morphology of the 3D-C/SiC is rougher, and pullout length of the fiber tows is longer. At the same time the 3D-C/SiC has higher tensile creep resistance. The tensile curve and the tensile creep curve of both materials consist of a series of flat step. These phenomena can be explained by the non-continuity of the damage.
关键词:
2D-C/SiC
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null
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null
