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《中国科学院院刊(英文版)》2003,17(1):21-21
A research team led by Dr LuKe of CAS Institute of MetalsResearch (IMR) has achievedprogress in solving the problem ofnitriding the surface of metal mate-rials via nanotechnology.Nitriding processes are a sur-face-modification technique used toproduce optimized structure andproperties in order to improve theglobal performance of the materials.However, the processes have to beperformed at high temperatures fora long duration and may induce se-rious deterioration of the substratein many fami… 相似文献
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王秀忠 《济南教育学院学报》2001,(3):74-77
运用键级守恒莫斯势法对金属Pt、Rh、Pd、Ni(111)等表面上的N0 CO还原反应的机理进行了探讨,并对Pt、Rh、Pd、Ni的催化活性作了比较,计算结果表明在低覆盖度下,NO CO还原反应过程中,N2O为主要的中间反应物种,金属Rh是较好的催化剂。计算结果与实验结果符合较好。 相似文献
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近年来,防腐涂料的应用日益广泛,传统的涂料在钢铁表面涂装时,都要求彻底除锈,这即耗费大量工时又增加费用,有些大型的工程的建造周期长,在工程建成时往往由于预涂底漆损坏而重新生锈,不得不对设备主体进行二次除锈,工程量很大。而且锈迹几乎不能完全除净,在很大程度上影响了钢结构防腐蚀效果。为此,研究开发可以直接涂装在一定锈蚀的金属表面的新型涂料,意义非常重大。60年代以来,我国已研究、开发出了一系列溶剂型带锈防腐涂料,但这类涂料含有大量的有机溶剂,毒性大,对环境污染严重。因此,研究水性带锈防腐涂料,克服溶剂型带锈防腐涂料的一些缺点,是目前研究带锈防腐涂料的热点之一。 相似文献
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以硫醇分子在金表面的自组装为例,综述了有机分子在金属表面自组装的基本原理,并以硫醇分子在单晶金表面自组装作为模型系统.证明了通过基底表面分子-分子以及分子-基底之间的相互作用,并控制基底的温度及覆盖可以获得分子簇、准一维排列和二维重叠的分子结构. 相似文献
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It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas, such as the impedance matching, the radiation efficiency and the radiation pattern, are seriously affected by the metallic surface. This paper presents the characteristics of the dipole-like antennas of ultra high frequency (UHF) radio frequency identification (RFID) tags that are placed close to metallic surfaces. The finite element method (FEM) and method of moment (MoM) were used to simulate the changes of the antenna parameters near the metallic surface. Two typical dipole-like antennas close to the metallic surface, a closed loop antenna and a loaded meander antenna, were modeled, and the performance was evaluated. Experiment was carried out and the results were in good agreement with the simulation, showing that a distance of 0.05λ-0.1λ (λ is the free space wavelength) from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable. 相似文献
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A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a per- sonal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model. 相似文献