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91.
Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and La2Ce2O7 (LC) were deposited by electron beam-physical vapor deposition (EB-PVD). The composition, interdiffusion, surface and cross-sectional morphologies, cyclic oxidation behavior of DCL coating were studied. Energy dispersive spectroscopy and X-ray diffraction analyses indicate that both LZ7C3 and LC coatings are effectively fabricated by a single LZ7C3 ingot with properly controlling the deposition energy. The chemical compatibility of LC coating and thermally grown oxide (TGO) layer is unstable. LaAlO3 is formed due to the chemical reaction between LC and Al2O3 which is the main composition of TGO layer. Additionally, the thermal cycling behavior of DCL coating is influenced by the interdiffusion of Zr and Ce between LZ7C3 and LC coatings. The failure of DCL coating is a result of the sintering of LZ7C3 coating surface, the chemical incompatibility of LC coating and TGO layer and the abnormal oxidation of bond coat. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL coating is an important development direction of TBCs. 相似文献
92.
Corrosion behavior and composition analysis of chromate passive film on electroless Ni-P coating 总被引:1,自引:0,他引:1
A passive film was formed on electroless Ni-P coating (ENPC) in a bath of K2Cr2O7 30 g/l. XPS and electrochemical methods were employed to analyze its chemical compositions and corrosion behaviors. The potentiodynamic polarization tests indicated the corrosion current of the passivated sample was 1/30 that of as-plated ENPC. The XPS analysis illustrated the film comprised Cr, Ni and O. The film thickness was evaluated to be a few nanometers according to the sputtering rate of Ar+ ion. High-resolution XPS spectra suggested that the detected Cr in film was in the form of trivalent compounds, Cr2O3 and Cr(OH)3. 相似文献
93.
We report in this Letter that when radiation is incident on a metal surface perforated with an array of ring-shaped subwavelength apertures, the phase difference between the propagating surface Bloch wave and the localized surface wave can be tailored by the geometrical parameters of the array so as to affect the shape of the transmission spectrum. Above the resonant frequency of the aperture, interference between the two kinds of surface waves leads to a minimum in the transmission spectrum, whereas below it, the interference leads to a maximum. We suggest that this feature provides flexibility in engineering surface-wave-based all-optical devices. 相似文献
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一般来说,18世纪以前的科学家主要是对一些零散的静电和静磁现象进行观察.中国古代较早地开始积累电学和磁学方面的知识,像雷电现象的观察和摩擦起电的经验,磁石吸铁和指向性的研究与应用都是早期研究的重要内容.特别是磁学的研究与应用对中国古代的生产、军事、航海、测量等技术的发展产生了重要作用,同时,在东西方科学与文化的交流上也发挥了巨大的作用. 相似文献
96.
C. Torres O. Alejos C. de Francisco J.M. Muñoz P. Hernández-Gómez 《Applied Physics A: Materials Science & Processing》2003,77(3-4):543-547
This paper describes a robust and fast fitting procedure applicable for relaxing processes that cannot be understood as a discrete sum of single processes but require an activation energy distribution. The method is based on a set of closed-form expressions that allow the computation of the relaxation parameters directly from the isochronal curves obtained experimentally. The usefulness of this method is checked by analyzing the isochronal curves given by a theoretical energy distribution and the magnetic disaccommodation spectra observed in yttrium iron garnet (YIG) samples. PACS 02.60.Ed; 75.60.Lr; 75.50.Gg 相似文献
97.
Wang Muhan Lin Haifeng Mu Ruizhen Zhu Wenzhang Xiong Feibing 《Journal of Russian Laser Research》2021,42(4):494-500
Journal of Russian Laser Research - We report a single- and triple-wavelength Nd:GGG laser operating in the 1.3 μm wavelength range with 880 nm laser diode pumping directly into the 4F3/2... 相似文献
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