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81.
K.Y. Cai College of Bioengineering Chong Qing University Chongqing China 《金属学报(英文版)》2007,20(2):148-156
Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techniques of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and light microscopy (LM). The surface presented increased sodium concentration on treated titanium films with ion dose increasing, except for the group with the highest ion dose of 4× 1017 ions/cm2. XPS depth profiling displayed that sodium entered titanium film around 25-50 nm depth depending on its implantation ion dose. AFM characterization showed that sodium ion implantation treatment changed the surface morphology from a relatively smooth titanium film to rough surfaces corresponding to different implantation doses.After sodium implantation, implanted titanium films presented big particles with island structure morphology. The surface morphology and particle growth displayed the corresponding trend.Fibrinogen adsorption on these titanium films was performed to correlate with the surface properties of treated titanium films. The results show that protein adsorption on ion-implanted samples with dose of 2 × 1017 and 4 × 1017 are statistically higher (p < 0. 01) than samples treated with dose of 5×1016 and 1 ×1017, as well as the control samples. 相似文献
82.
PREPARATION OF MULTI-WALLED CARBON NANOTUBES USING NiO CATALYST SYNTHESIZED BY HYDROTHERMAL METHOD 总被引:2,自引:0,他引:2
Y.J. Zhu Y.L. Chen X.M. Xue Y.M. Chen C.Y. Wu T.C. Kuang S.H. Li and H.Y. Zhang) Department of Applied Physics Guangdong University of Technology Guangzhou China) Center of Analysis Testing Guangdong University of Technology Guangzhou China) Faculty of Material Energy Guangdong University of Technology Guangzhou China 《金属学报(英文版)》2003,16(5):416-420
The Ni(OH)2/SiO2 binary colloid was prepared using Ni(NO3)2.6H2O and (C2H5O)4SiO4 as starting materials and was used to form NiO/SiO2. composite powder by hydrothermal method and desiccant method in open air respectively. Multi-walled carbon nanotubes (MWCNTs) were synthesized respectively by chemical vapor deposition using the NiO/SiO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of MWCNTs were compared by XRD, TEM and SEM. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure MWCNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/SiO2 powder prepared by hydrothermal method as catalyst. 相似文献
83.
X. Gao Y.F. Zheng W. Cai L.C. ZhaoSchool of Materials Science Engineering Harbin Institute of Technology Harbin China 《金属学报(英文版)》2003,16(5):401-406
The phase transformation behavior and micro structure of Nb-Ru alloys have been studied by DSC, X-ray diffraction, optical microscopy, transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Two-step phase transformation of CsCl (β) →face-centered tetragonal (β)→ monoclinic (β") occurs during cooling from high temperature to room temperature. The lattice parameters of marten-sites of Nb-Ru alloys were found to increase with the increase of Nb content. The martensite variants exhibit triangular self-accommodating morphology, with alternating regular bands inside. The twinning relationship between the sub structural bands was found to be (101) type I mode, and this kind of twinning interface was straight, well-defined and coherent. 相似文献
84.
N.C. Si Z.H. Jia L.B. QiSchool of Materials Science Engineering Jiangsu University Zhenjiang China 《金属学报(英文版)》2003,16(5):385-394
Effect of carbon, compound RE, quenching temperature, pre-strain and recovery temperature on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloy was studied by bent measurement, thermal cycle training, SEM etc. It was shown that the grains of alloys addition with compound RE became finer and SME increased evidently. SME of the alloy was weakening gradually as carbon content increased under small strain (3%). But in the condition of large strain (more than 6%), SME of the alloy whose carbon content range from 0.1% to 0.12% showed small decreasing range, especially of alloy with the addition of compound RE. Results were also indicated that SME was improved by increasing quenching temperature (>1000℃). The amount of thermal induced martensite increased and the relative shape recovery ratio could be increased to more than 40% after 3-4 times thermal training. The relative shape recovery ratio decreased evidently depending on rising of pre-strain. Furthermore, because speed of martensite transi 相似文献
85.
G.B. Liu W.L. Wang C.G. Hu K.J. Liao Q. Feng L.H. FengDepartment of Applied Physics Chongqing University Chongqing ChinaDepartment of Material Science Sichuan University Chengdu ChinaOptoelectron Technology System Laboratory of Education Ministry Chongqing University Chongqing China 《金属学报(英文版)》2003,16(4):313-318
The effect of annealing treatment on the structure of CdS films was investigated. The cadmium sulfide thin films were prepared by chemical bath deposition, and were annealed at nitrogen atmosphere at different temperatures. The films were characterized by SEM and XPS (X-ray photoelectron spectroscopy). X-ray photoelectron spectroscopy was used to examine the chemical states on the CdS films surface. It was found that thermal annealing could produce large grains of CdS thin films, remove the air contamination and reduce the oxygen content on the CdS films surface. Therefore, the CdS films changed more uniform and smoother surface after thermal annealing. 相似文献
86.
L. Chen Z.Y. Liu D.C. Zeng W.Q. Qiu Z.H. Yuan S.S. Lin H.J. HouInstitute of Materials Science & Technology College of Mechanical Engineering South China University of Technology Guangzhou ChinaGuangzhou Research Institute of Non-Ferrous Metals Guangzhou China 《金属学报(英文版)》2003,16(4):271-275
DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the negative bias of 100V. 相似文献
87.
X.B. Qin S. J. Cheng and X.F.BianKey Laboratory of Liquid Structure Heredity of Materials Ministry of Education Shandong University Ji''''nan China Mechanical Engineering Department Shandong University of Technology Zibo China 《金属学报(英文版)》2003,16(6):513-518
The structure of Fe-2.0%C alloy melt was investigated at 1580, 1560, 1540 and 1450℃ by using an X-ray diffractometer respectively. The results showed that with decreasing temperature, the average atoms of cluster, the coordination numbers, the correlation radius and the atom density increased, whereas the pre-peak of the structure factors curve remained almost at the same position. The appearance of the pre-peak indicated that the liquid structure and the solid structure of the Fe-2.0%C alloy were correlated. 相似文献
88.
A SiC whisker-toughened MoSi2-SiC-Si coating was prepared on carbon/carbon (C/C) composites surface by a two-step technique of slurry and pack cementation, and the effects of thermal shock and oxidation on the mechanical property of the coated C/C were studied. The flexural strength of C/C composites was improved by 6.8% after coated by SiC whisker-toughened MoSi2-SiC-Si. After thermal cycle between 1773 K and room temperature in air for 10 times, the mass loss of the coated sample was 5.08% and the percent... 相似文献
89.
Dong CHEN ) Jingdong CHEN ) Yinglu ZHAO ) Hailiang HUO ) Benhai YU ) Deheng SHI ) ) College of Physics Electronic Engineering Xinyang Normal University Xinyang China ) College of Physics Electronic Engineering Ludong University Yantai China 《金属学报(英文版)》2009,22(5)
The crystal and electronic structures of LaNi4.75Sn0.25 intermetallics and LaNi4.5Sn0.5Hy (y=2.0, 2.5) intermediate phase have been investigated by the full-potential linearized augmented plane wave (FP-LAPW) method. Hydrogen occupation sites in LaNi4.5Sn0.5Hy have been determined based on Westlake s criterions: (1) the minimum hole radius is 0.04 nm; (2) the minimum H-H distance is 0.21 nm; as well as geometry optimizations and internal coordinates optimizations. We find that hydrogen atoms prefer to occup... 相似文献
90.
Fengping YANG ) Qin SUN ) Wei HU ) ) School of Aeronautics Northwestern Polytechnical University Xi an China ) Institute of Orthopedic Oncology Tangdu Hospital Fourth Military Medical University Xi an China 《金属学报(英文版)》2009,22(2):123-130
Five types of tensile tests were conducted to study the yield behavior of 2A12-T4 aluminum alloy. Parallel finite element models were built for each test and solved with ABAQUS with different yield criterions. The result shows that any of the four criterions: von Mises yield criterion, Tresca criterion, Twin-Shear criterion and yon Mises criterion with hydrostatic pressure correction, overestimates the yield strengths of the specimens. Rather than hydrostatic pressure, Lode stress parameter is the key factor that affects the differences between experimental and simulation results. Based on this concept, a new yield model with Lode dependence modified from yon Mises criterion is postulated. Although one more parameter needs to be confirmed, the simulation results of this yield model are better than those of other criterions. 相似文献