傅里叶积分

它直接从位相物体振幅透过率的一般公式出发，运用傅里叶积分，求得二进制位相光栅各级衍射光强度的通式。

The series density formulae of the binary phase grating are obtained from the general complex amplitude transmittance formulae through Fourier integral .

在物体壁面与流体间的换热系数为有限值或无限大情况下，用傅里叶积分和δ函数对半无限大物体非稳态导热作了全面分析。

Sing Fourier Integral and δ - function an analysis of unsteady heat conduction for semi-infinite body is given in detail , assuming that the coefficient of convective heat transfer on the boundary surface between solid body and fluid is definite or infinite .

利用傅里叶积分变换、三角级数和复变函数等方法，求得了双向非对称配筋、板边简支CRCP在静荷载作用下位移和应力的解析解。

The static solution for displacements and stresses of CRCP with unsymmetrical reinforced in tow dimension and simply supported edges is obtained by using triangular series and Fourier transformation .

Fellgett首先利用干涉图和对干涉图进行傅里叶积分变换的方法来测量和研究光谱。1965年，J。

After that , P. Fellgett made use of the interference figure to measure and explore spectrum by Fourier transform for the first time in 1949 . In 1965 , J.

作为傅里叶积分特例的傅里叶级数是分析连续性周期信号行之有效的古典方法。

Fourier series is a classical method for analyzing periodical signals .

利用傅里叶积分变换法研究了超短脉冲高斯光束通过透镜的聚焦特性，给出了透镜焦平面上光强的空间、时间分布，以及能量密度分布。

Based on the Fourier transform , the focusing of ultrashort pulsed Gaussian beams by a lens is studied . Spatial and temporal intensity distributions and energy density of focused ultrashort pulsed Gaussian beams at the focal plane are presented .

本文以迭加原理、开拓法、齐次化原理及傅里叶积分变换为工具求得了半直线上第三类、第二类及第一类边界条件下热传导方程混合问题的三个求解公式。

In this paper three solving formulae of mixed problems about heat conduction equations on ray are obtained under . The third , second and first boundary conditions by using superposition principle , extension method , Homogenization principle and Fourier integral transformation as means .

求解分数傅里叶变换衍射积分的一种快速算法

A Fast Algorithm for Calculating the Fractional Fourier Transform Diffraction Integral

通过变频率间隔方法，直接利用傅里叶变换数值积分计算频散曲线，有效提高了瑞雷波勘探对深层的分辨能力。

Through changed frequency interval method , using fourier transform value integration to calculating dispersion curve directly , improving the deep resolution of Rayleigh wave significantly . 4 .