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超高声速飞行器光学窗口气动光学效应分析 总被引:6,自引:0,他引:6
超高声速飞行器在大气中飞行时,由于气动热和气动力的作用,光学窗口会产生严重的气动光学效应,使目标图像发生像偏移、抖动、模糊和能量衰减。利用有限元分析方法对光学窗口的热光效应、弹光效应和窗口热变形进行研究,计算了由热光学效应、光学窗口热变形引起的点扩散函数峰值大小及峰值位置(像偏移)随时间的变化趋势。根据对温度场的分布分析,计算了温度梯度对透过率的影响以及透过率与窗口热辐射随时间变化的趋势,可为光学窗口的设计、材料的选择及后期的图像处理提供依据。 相似文献
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Simulation of Electromagnetic Wave Logging Response in Deviated Wells Based on Vector Finite Element Method 总被引:1,自引:0,他引:1 下载免费PDF全文
The vector finite element method of tetrahedral elements is used to model 3D electromagnetic wave logging response. The tangential component of the vector field at the mesh edges is used as a degree of freedom to overcome the shortcomings of node-based finite element methods. The algorithm can simulate inhomogeneous media with arbitrary distribution of conductivity and magnetic permeability. The electromagnetic response of well logging tools are studied in dipping bed layers with the borehole and invasion included. In order to simulate realistic logging tools, we take the transmitter antennas consisting of circular wire loops instead of magnetic dipoles. We also investigate the apparent resistivity of inhomogeneous formation for different dip angles. 相似文献
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A New Method for Calculation of Single Seismic Phase of Cylindrically Multilayered Media Including Liquid Interlayer 下载免费PDF全文
A new method based on generalized reflection and transmission (R/T) coefficients method is proposed to calculate the single seismic phase (SSP) of cylindrically multilayered media including liquid interlayer. The use of normalization factors and normalized Lamé coefficients makes the algorithm stable numerically. Using the modified R/T matrices, we derive the iterative expressions of generalized R/T matrices, and by using the iterative relation we determine the SSP of each interface and the full waveforms. To show the superiority of this new approach for investigating of reflection and transmission properties of cylindrically multilayered media, we simulate the full waveforms and SSPs of cased hole model with annulus I (casing-cement interface) channelling (or, cross-flow). The generalized reflection coefficient spectra and SSPs of interfaces obtained show the propagation mechanism of each component of full waveform clearly. 相似文献
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强化采油中常用的表面活性剂石油磺酸盐在通过油层时会发生色谱分离作用,其完整性受到破坏,从而影响与原油界面的活性。采用高效液相色谱法(HPLC),通过测定磺酸盐色谱分离因子,定量地描述石油磺酸盐在岩心多也介质的色谱分离程度。应用该方法可以考察影响色谱分离因子的因素,以优化化学驱油配方的设计。该方法具有灵敏度高、可靠、用量少等特点。 相似文献
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对颜料进行准确、无损或微损分析是文物保护领域研究的热点与难点。随着文物保护研究的不断开展及多学科技术的广泛交叉、融汇,各种光谱技术逐渐被应用到彩绘文物颜料的分析之中。从元素分析、结构分析、微区与形貌分析三方面探讨了X荧光光谱分析法、激光拉曼光谱法、光导纤维反射光谱法等常用光谱分析技术在彩绘文物颜料分析中的应用、特点、局限性及应用前景。 相似文献
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