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排序方式: 共有192条查询结果,搜索用时 15 毫秒
81.
82.
K. Sumi H. Qiu H. Kamei S. Moriya M. Murai M. Shimada T. Nishiwaki K. Takei S. Miyashita M. Hashimoto 《Thin solid films》1998,330(2):5274-189
Sol-gel Pb(Zr0.56Ti0.44)0.90(Mg1/3Nb2/3)0.10O3 (PZT-PMN) films were prepared onto the Ti/Pt/Ti bottom electrode by multilayer spin coating. The film thickness ranged from 0.22 to 0.88 μm. The Pt top electrodes were deposited on the PZT-PMN films by DC sputtering. The structural and ferroelectric properties of PZT-PMN films were investigated as a function of film thickness by X-ray diffraction (XRD), scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (XTEM), and by measuring the relative permittivity. The film retains the tetragonal perovskite structure with the [111] and [100] preferred orientations perpendicular to the film surface independent of film thickness. The [100] texture increases with increasing film thickness although the [111] texture is always predominant. The film consists of columnar grains. The average grain size is nearly independent of film thickness. The surface layer containing fine grains about 30 nm in diameter is induced on the top of the film. As the film thickness exceeds 0.44 μm, the number of the fine grains decreases remarkably. The crystalline interface layer about 10 nm thick is formed between the film and the bottom electrode. This interface layer is composed of Pt, Pb, Zr, Ti and O, while it is rich in Ti and deficient in Pb and O as compared with the inside of the film. The measured relative permittivity of the film increases with increasing film thickness, following the low permittivity interface model. On the basis of this model, the relative permittivity is estimated to be 3200 for the intrinsic PZT-PMN film, 750 for the surface layer and 50 for the interface layer. 相似文献
83.
Switching surge duty test imposing the highest power dissipation on high voltage metal oxide arresters has usually been done with a single phase circuit due to the limit of test facilities, in spite of complex multi-phases in a service system. The purpose of this paper is to propose new equivalent line constants and reasonable conditions of charging voltage in a test circuit, which were derived from the application study of surge arresters on double circuits and transposed 500kV lines. So-called positive, negative, zero, self and mutual mode impedances are not equivalent. Other impedances must be used and some correctiorts for charging voltage are required in a transmission line discharge test. 相似文献
84.
S Niho K Suzuki T Yokose T Kodama Y Nishiwaki H Esumi 《Canadian Metallurgical Quarterly》1998,152(4):1065-1069
Sclerosing hemangioma of the lung remains poorly understood, and it is still unclear whether this lesion is neoplastic or not. It consists of two major cell types, pale cells and cuboidal cells. We analyzed the clonality of each cell types from six female cases of surgically resected sclerosing hemangioma. The pale cells and cuboidal cells were separated by microdissection from methanol-fixed sections, and DNA was extracted for clonal analysis based on an X-chromosome-linked polymorphic marker, the human androgen receptor (HUMARA) gene or the phosphoglycerate kinase (PGK) gene. The HUMARA and PGK genes were found to be amplified with or without digestion by the methylation-sensitive restrictive endonuclease HpaII. Five of six cases were informative. Pale cells and cuboidal cells showed the same monoclonality in all of the informative cases, whereas the control cells showed a polyclonal pattern. Our results demonstrated that sclerosing hemangioma is caused by monoclonal expansion of cells, confirming that it is a neoplasia. Moreover, the present data indicate that both pale cells and cuboidal cells are derived from the same cell. 相似文献
85.
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87.
Tanaka Hiroaki Tsuge Ayao Hirata Masaru Nishiwaki Nuchi 《International Journal of Heat and Mass Transfer》1973,16(6):1267-1288
In this paper, turbulent heat and momentum transfer for a fluid forced through a vertical tube is considered. First, the authors study a shearing-stress distribution in a tube, by taking the buoyancy force and also the inertia force due to acceleration into consideration. It is proved that the effects of both forces operate quite similarly and result in a very rapid decrease of the shearing stress near the wall. By considering how the velocity profile depends upon the shearing-stress gradient at the wall, the authors deduce the criteria for the prominent effects of buoyancy and acceleration. Second, by assuming that the turbulent boundary layer is constructed by the superposition of the locally developed layers, the authors propose an approximate theory to calculate velocity and temperature profiles under the large effects of buoyancy and acceleration. Thirdly, based on the above theory, a criterion of the reverse transition from turbulent to laminar flow is proposed. 相似文献
88.
Nishiwaki K Kuffner J Kagami S Inaba M Inoue H 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2007,365(1850):79-107
This paper gives an overview of the humanoid robot 'H7', which was developed over several years as an experimental platform for walking, autonomous behaviour and human interaction research at the University of Tokyo. H7 was designed to be a human-sized robot capable of operating autonomously in indoor environments designed for humans. The hardware is relatively simple to operate and conduct research on, particularly with respect to the hierarchical design of its control architecture. We describe the overall design goals and methodology, along with a summary of its online walking capabilities, autonomous vision-based behaviours and automatic motion planning. We show experimental results obtained by implementations running within a simulation environment as well as on the actual robot hardware. 相似文献
89.
90.
A. Chiril P. Bloesch S. Seyrling A. Uhl S. Buecheler F. Pianezzi C. Fella J. Perrenoud L. Kranz R. Verma D. Guettler S. Nishiwaki Y.E. Romanyuk G. Bilger D. Brmaud A.N. Tiwari 《Progress in Photovoltaics: Research and Applications》2011,19(5):560-564
Development of a Cu(In,Ga)Se2 thin film solar cell on a polyimide film with a conversion efficiency of 17.1%, measured under standard test conditions at the European Solar Test Installation (ESTI) of the Joint Research Centre (JRC) of the European Commission, Ispra, is reported. The drastic improvement from the previous record of 14.1% efficiency is attributed to a more optimized compositional grading, better structural and electronic properties of the absorber layer as well as reduced reflection losses. Basic film and device properties, which led to the improvement in the efficiency record of flexible solar cells are presented for the new process and compared to the old process. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献