共查询到20条相似文献,搜索用时 62 毫秒
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B.A. Mamedov A.S. Ekeno?lu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2008,109(3):527-530
A new algorithm is presented for calculating the Bernoulli numbers valid for all values of their argument. We introduce a simple, new analytical computer method for calculating the Bernoulli numbers on the basis of their integral expressions. The formula given in this study for the evaluation of Bernoulli numbers shows good rate of convergence and numerical stability with existing formulas. 相似文献
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利用原始光强信号实现空间方位失调角高精度传递新方法 总被引:6,自引:2,他引:4
现有基于正弦波磁光调制偏振光的方位失调角传递方法存在精度不高的问题,提出了一种利用原始光强信号中极值点信息实现方位失调角高精度传递的新方法。建立了基于任意位置光强信号求解初始光强的模型,推导了大角度范围内粗略失调角的计算公式并给出了实现方案,提出了在小角度范围内比现有方法近似精度更高的获取失调角信息的方法。仿真结果以及误差分析表明:利用该方法得出的方位失调角传递误差远远小于现有方法,为实现空间方位失调角高精度传递提供了一种参考。 相似文献
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We present a new approach to describe the three-body continuum with a square integrable basis and show some examples to assess its efficiency. The formulation is done elegantly in the hyperspherical formalism and the tail behavior is appropriately corrected with use of the Green??s function. The efficiency of this approach is shown in a simple solvable problem by calculating the electric dipole strength function of a three-body system and comparing it to that obtained with the complex scaling method, which is widely used for calculating the strength function. 相似文献
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A new method for calculating image intensity distribution in partially coherent illumination is described. The method is based on the coherent-mode representation of the cross-spectral density function of illumination field and allows considerable reduction of the computational effort needed for image intensity calculation in comparison with the direct method. The computational efficiency of the method is larger the more coherent is the illumination in a global sense. An example of calculating image intensity for Schell-model illumination is compared with theoretical results. 相似文献
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The definition of the time varying force on a tip with internal degrees of freedom in atomistic molecular dynamics (MD) simulations of scanning force microscopy experiments is discussed. We show that the static expression for the tip force is inadequate for calculating force fluctuations within the MD simulations and suggest a different method of calculating the tip force. By studying the size of tip force fluctuations for different tip models and various tip positions with respect to the surface, we demonstrate that the new method works equally well in both static and dynamic cases. 相似文献
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《Journal of computational physics》2003,184(1):1-36
A method is presented for representing curved boundaries for the solution of the Navier–Stokes equations on a non-uniform, staggered, three-dimensional Cartesian grid. The approach involves truncating the Cartesian cells at the boundary surface to create new cells which conform to the shape of the surface. We discuss in some detail the problems unique to the development of a cut cell method on a staggered grid. Methods for calculating the fluxes through the boundary cell faces, for representing pressure forces and for calculating the wall shear stress are derived and it is verified that the new scheme retains second-order accuracy in space. In addition, a novel “cell-linking” method is developed which overcomes problems associated with the creation of small cells while avoiding the complexities involved with other cell-merging approaches. Techniques are presented for generating the geometric information required for the scheme based on the representation of the boundaries as quadric surfaces. The new method is tested for flow through a channel placed oblique to the grid and flow past a cylinder at Re=40 and is shown to give significant improvement over a staircase boundary formulation. Finally, it is used to calculate unsteady flow past a hemispheric protuberance on a plate at a Reynolds number of 800. Good agreement is obtained with experimental results for this flow. 相似文献
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邵宇飞 《原子与分子物理学报》2016,33(4):736-744
基于晶体的微观结构提出了一种计算晶体宏观弹性应变场的方法,将该方法应用于金属晶体Fe,得到的应变场与连续介质理论预测结果吻合地很好,从而证明了该方法的准确性.以该方法为基础,进一步考虑无限小应变与有限应变的差值,发现应变差值在晶体剧烈变形区域内较强,对金属晶体Cu位错应变场的计算表明这种应变差异可以用来描述位错的运动状态和芯域结构.该方法可为评估晶体缺陷附近应变状态提供依据. 相似文献
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We develop the multi-slice method for calculating wavefunction of a crystal consisting of atomic columns. The new method reduces numerical calculation from two dimensions to one dimension and is much faster than that of the traditional multi-slice method. The calculated result by the one-dimensional method is in agreement with that of the traditional one. 相似文献
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邵宇飞 《原子与分子物理学报》2017,34(6)
基于晶体的微观结构提出了一种计算晶体宏观弹性应变场的方法,将该方法应用于金属晶体Fe,得到的应变场与连续介质理论预测结果吻合地很好,从而证明了该方法的准确性.以该方法为基础,进一步考虑无限小应变与有限应变的差值,发现应变差值在晶体剧烈变形区域内较强,对金属晶体Cu位错应变场的计算表明这种应变差异可以用来描述位错的运动状态和芯域结构.该方法可为评估晶体缺陷附近应变状态提供依据. 相似文献
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A new method for calculating the 3-dimensional magnetic field is described. The modified scalar potential is used to reduce the order of the coupled equations in the comparison with the vector potential under the same node number. 相似文献
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通过对带有耦合器的单驻波腔进行等效电路分析,推导出可计算带有耦合波导的单谐振腔外部Q值的反射相位法,该方法通过计算不同频率的反射相位来确定谐振频率和外部Q值。详细叙述了在CST Microwave Studio中用谐振模式求解法、直接时域跟踪法和反射相位法进行计算的步骤;用这3种方法分别计算了二次发射微波电子枪的外部Q值并和实验测量结果做了比较。结果显示3种计算方法都有很高的精度,但反射相位法的速度最快,耗时1 071 s。计算发现外部Q值与耦合口长度的4.1次方成反比。 相似文献