Papers by Author: Y. Shi

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Authors: J. Campi, Y. Shi, Yan Bin Luo, Feng Yan, Young Kook Lee, Jian Hui Zhao
Authors: Zhe Chuan Feng, Ian T. Ferguson, R.A. Stall, K. Li, Y. Shi, H. Singh, Kiyoshi Tone, Jian Hui Zhao, A.T.S. Wee, K.L. Tan, F. Adar, B. Lenain
Authors: Hong Wei Zhang, Guo Xiong Zhang, Y. Shi
Abstract: Reverse engineering of free-form surfaces is one of the most challenging technologies in advanced manufacturing. With the development of industry more and more sculptured surfaces, such as molds and turbine blades, are required to measure quickly and accurately. Optical non-contact probes possess many advantages, such as high speed, no measuring force, in comparison with contact ones. The ability of stereovision probe with CCD cameras in gathering a large amount of information simultaneously makes it the most popularly used one in sculptured surface measurements. So based on the laser triangular principle, a measuring and testing device with two CCD cameras was designed, and its accuracy was analyzed. With a virtual 3D target in form of a grid plate, all the intrinsic and extrinsic parameters of CCD camera including the uncertainty of image scale factor and optical center of camera can be readily calibrated. In order to obtain all the required data with high accuracy in a short time, the curvature-based adaptive sampling strategy is presented. Due to huge amount of arbitrary scattered points, the Delaunay triangular division and Bezier interpolation and NURBS interpolation are applied to get a continuous surface.
Authors: Y. Shi, Masashi Suezawa, Feng Mei Wu, M. Imai, Y.D. Zheng, Koji Sumino
Authors: S.M. Liu, Shu Lin Gu, Feng Qin, Su Min Zhu, Jian Dong Ye, W. Liu, X. Zhou, R. Zhang, Y. Shi, Y.D. Zheng
Abstract: In this paper we have characterized the performance of a vertical metalorganic chemical vapor deposition (MOCVD) reactor used for deposition of ZnO thin films. The equations of the mathematical model are solved numerically using a control-volume-based finite difference method. A two-dimensional model is put forward to study the dependence of the growth rate on the inlet flow rate and susceptor temperature. The mass-fraction distribution of the reactants has been studied as a function of the position above the substrate, which shows that gas phase pre-reaction in our reactor is well confined. The simulation results are useful for the practical growth of ZnO.
Authors: Jian Dong Ye, Shu Lin Gu, Su Min Zhu, S.M. Liu, Feng Qin, W. Liu, X. Zhou, R. Zhang, Y. Shi, Y.D. Zheng
Abstract: The morphology evolution of ZnO films grown on sapphire (0001) by MOCVD have been studied as a function of buffer growth time and temperature by means of atomic-force microscope (AFM), x-ray diffractions (XRD) and optical microscopy. When the buffer growth temperature decreased to 450°C, the surface became smooth greatly, indicating the transition from typical 3D island growth to quasi-2D growth mode. As the buffer growth time exceeds 5min, the micron-sized pit-like features are formed. It is due to the lack of stabilization of adatoms under the “etching” action of ionized O2/Ar during high temperature buffer annealing
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