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21.
A. Simon Z. Kntor 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2002,190(1-4):351-356
The formation and deposition of particulates by pulsed laser deposition of Si1−xGex semiconductor alloy thin films are discussed. Using Rutherford backscattering spectrometry with micrometer lateral resolution (micro-RBS) the film composition was measured with high accuracy, even in the presence of particulates with a high areal density of 20,000–30,000 particulates per mm2. We show that on impact of a particulate, the part of the thin film which is already deposited probably melts and its Ge content segregates to the surface. 相似文献
22.
High-temperature and controlled humidity treatment before drying has proven to be highly effective in preventing surface checks by forming drying sets in the surface layer of boxed-heart square timber in Japan. In this study, we examined the differences of the surface drying sets on sugi timber under different treatment temperatures. As a result, the width of a surface check after drying was much smaller at a treatment temperature of 120°C than at 80°C, and this indicates that the drying set with 120°C treatment would be larger than that with 80°C treatment. Also we observed that treatment temperature had a greater effect on the drying set as the drying advanced. 相似文献
23.
Preparation of submicrometer-sized titania hollow spheres by templating sulfonated polystyrene latex particles 总被引:1,自引:0,他引:1
Akhmad Syoufian 《Materials Letters》2007,61(7):1572-1575
Submicrometer-sized titania hollow spheres with tunable shell thickness and smooth surfaces have been successfully synthesized by employing sulfonated polystyrene (PS) latex particles as a template in sol-gel method. The structure of the particles was characterized by scanning electron microscopy and transmission electron microscopy. The shell thickness was readily tuned by altering the concentration of titanium tetrabutoxide (TBOT) in ethanol solutions. The surface roughness as well as the shell thickness has the tendency to increase with the increase in the concentration of TBOT. The diameter of the hollow spheres was on the average of 20-26% smaller than the diameter of template PS latex particles. Some titania fragments were also observed for the sample with the highest TBOT concentration. 相似文献
24.
《Materials and Manufacturing Processes》2007,22(1):5-8
The technological properties of the hot-work tool steels depend on their microstructural quality induced by the production process and the heat treatment. One of the frequently applied methods to improve microstructure is preheat treatment. The treatment of carbonitriding X37CrMoV5-1 steel has been investigated in fluidized bed furnaces. Thickness and phase composition have been conducted using optical microscopy Neophot 32 and scanning microscopy, JEOL 5400, after etching in nital. 相似文献
25.
26.
Initial stages of surface erosion have been studied for NaCl and LiF single crystals bombarded by Ar+ ions with 20 keV. For irradiation with doses D=1010-1011 ions/cm2, exoelectron emission has been used, whereas for higher doses, we have used electron microscopy. Two stages of initial surface erosion have been identified; for small doses, there is slow development of atomic-scale roughening, which reaches its peak when areas damaged by closest incident ions start to overlap, and then, beginning with D=1016 ions/cm2, there is rapid etching, deep into the crystal, followed by the emergence of secondary microscopic structure, i.e. caverns, concentric closed steps and terraces. Ion-induced surface structure of alkali halide crystals has been shown to depend strongly on the presence of foreign particles on the surface, as well as on segregation. Topography of thin carbon films and some metals have been discussed. 相似文献
27.
The influence of the substrate nature on the structure and morphology of ITO thin films grown by thermal evaporation in vacuum is investigated. The as-prepared metal films with Sn/In molar ratio of 0.1 were subsequently annealed for 2 h at 723 K in air (to obtain tin doped indium oxide), then annealed in vacuum at 523 K, followed by UV irradiation (to reduce the electrical resistivity). Irrespective of substrate nature, XRD data evidence a (222) preferential orientation in films. Substrate nature, annealing in vacuum and UV irradiation influence the structure, morphology, optical, electrical and surface wetting properties of the films' surface. 相似文献
28.
影响轧辊表面粗糙度的因素很多,为此对影响辊面粗糙度的因素进行了系统分析和实验研究,得出了轧辊和砂轮的速度、砂轮粒度、砂轮直径及磨削液等主要因素对轧辊表面粗糙度影响的一般规律。利用回归分析的方法建立了轧辊表面粗糙度的数学模型,并将计算值与实测值进行了比较,发现两者基本一致。此项研究为适时控制冷轧带钢在线磨辊辊面粗糙度提供了计算模型。 相似文献
29.
介绍了针对早期建筑的混凝土桥梁碳化情况采用H52-S4环氧厚浆涂料进行封闭保护、防腐处理的施工方法及施工工艺,并提出施工中应注意的有关事项,对温度影响、表面气泡处理进行了讨论,提出合理化建议。 相似文献
30.
The aim of this research is to investigate how ammonia treatment of the surface can influence the activity of a viscose-based activated carbon cloth (ACC) for the oxidative retention of H2S and SO2 in humid air at 25 °C. Surface basic nitrogen groups were introduced either by treatment with ammonia/air at 300 °C or with ammonia/steam at 800 °C. The pore structure of the samples so prepared was examined by adsorption measurements. Changes in the surface chemistry were assessed by X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and temperature programmed desorption (TPD). The change of ACC activity could not be merely attributed to surface nitrogen groups but to other changes in the support. Ammonia/steam treatment improved ACC performance the most, not only by introducing nitrogen surface groups, but also by extending the microporosity and by modifying the distribution of surface oxygen groups. Successive adsorption-regeneration cycles showed important differences between oxidative retention of H2S and SO2 and the subsequent catalyst/support regeneration process. 相似文献