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51.
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Excitation functions for103Rh (α,xn);x = 1–4 and103Rh (α,αxn);x = 1–3 reactions were measured up to 50 MeV bombarding energy using stacked foil activation technique and high purity germanium
(HPGe) γ-ray spectroscopy method. The experimental results were compared with calculations considering equilibrium as well
as pre-equilibrium hybrid model of Blann (ALICE/90). It is found that the initial exciton configurationn
0 = 4(4p0h) gives fairly good agreements for (α,xn) reactions. There seems to be indication of direct inelastic scattering effects in (α,αxn)-type of reactions. 相似文献
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The UV-light-induced hydrophilicity of amorphous titanium dioxide thin films obtained by radio frequency magnetron sputtering deposition was studied in relation with film thickness. The effect of UV light irradiation on the film hydrophilicity was fast, strong and did not depend on substrate or thickness for films thicker than a threshold value of about 12 nm, while for thinner films it was weak and dependent on substrate or thickness. The weak effect of UV light irradiation observed for the ultra-thin films (with thickness less than 12 nm) is explained based on results of measurements of surface topography, UV-light absorption and photocurrent decay in vacuum. Comparing to thicker films, the ultra-thin films have a smoother surface, which diminish their real surface area and density of defects, absorb partially the incident UV light radiation, and exhibit a longer decay time of the photocurrent in vacuum, which proves a spatial charge separation. All these effects may contribute to a low UV light irradiation effect on the ultra-thin film hydrophilicity. 相似文献
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Preparation and characterization of slice-like Cu2(OH)3NO3 superhydrophobic structure on copper foil
Superhydrophobic structure was prepared on copper foil via a facile solution-immersion method. Thus slice-like Cu2(OH)3NO3 crystal was prepared on the surface of the copper foil by sequential immersing in an aqueous solution of sodium hydroxide and cupric nitrate. And the superhydrophobic structure was obtained by modifying the slice-like Cu2(OH)3NO3 crystal with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-17). The morphologies, chemical compositions and states, and hydrophobicity of the surface-modifying films on the copper foil substrates were analyzed by means of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement. Moreover, the thermal stability of the slice-like structure was also evaluated using thermogravimetric analysis (TGA). It was found that roughening of the copper foil surface helped to increase the hydrophobicity to some extent, but no superhydrophobicity was obtained unless the slice-like Cu2(OH)3NO3 crystal formed on the Cu substrate was modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane. Besides, the superhydrophobicity of the FAS-17-modified slice-like Cu2(OH)3NO3 structure was closely related to the surface morphology. And this hydrophobic structure retained good superhydrophobic stability at elevated temperature and in long-term storage as well, which should be critical to the application of Cu-matrix materials in engineering. 相似文献
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Element segregation on the surfaces of pure aluminum foils 总被引:2,自引:0,他引:2
The surface segregation trend of trace elements in pure aluminum foils was investigated by density functional theory. The model of nine-layer Al(1 0 0) slab substituted partially by trace element atoms was proposed for calculating surface segregation energy. The calculating results show that (i) B, Mg, Si, Ga, Ge, Y, In, Sn, Sb, Pb and Bi exhibit negative segregation energy and possibly move to the surface, while Be, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zr exhibit positive segregation energies and migrated into the bulk; (ii) the segregation energy was found to be related with the covalent radius, the relaxed position at the surface of the substituting atom and the surface energy; (iii) the segregation behavior of trace element generates lots of defects and dislocation, which can increase the initial pitting nucleation sites in the surface of aluminum foils; (iv) the impurity atom concentration was tested with Pb-doped surfaces, the calculated negative segregation energies in all coverage increases rapidly with the Pb coverage. These conclusions are helpful for designing of the chemical composition and to advance the tunnel etching of aluminum foils. 相似文献
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独创了一款以多段同心圆轴梁为核心的电板箔机械强度综合测试机构,实现集抗拉强度和抗弯强度测试于一体的测试方案;在微处理器的控制下,实现了电板箔机械强度的全自动、智能化测试。与传统的测试方案相比,本测试方案科学、合理,节约了测试成本,测试效率显著提高,所提供的数据更适合生产需要,填补了国内技术空白,并将产生显著的经济效益。 相似文献
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为分析飞秒激光作用下金属材料的温度场及其影响因素,基于一维双温模型对飞秒激光作用下铜箔的温度场进行数值求解。采用脉宽100~800 fs,能量密度509.30~2 546.48 J/m2的激光参数进行计算,研究电子和晶格温度随时间和深度的变化规律。结果表明,电子温度在10-13 s时间尺度达到峰值,在此期间晶格温度保持不变,此后通过耦合作用二者在几ps时间尺度达到热平衡;脉宽越短,电子温升越快、峰值温度越高、耦合时间越短;而能量密度越大,电子温升越快、峰值温度越高、耦合时间越长。 相似文献