近似积分

However, combining image plane DHM with the phase-shifting in-line technique, the complex amplitude of reconstructed image can be obtained without using Fresnel integral, moreover the approximate error of reconstruction calculation is easily eliminated and the signal-to-noise ratio of reconstructed image is significantly improved.

理论分析和实验证明，用这种方法无需使用菲涅尔积分即可直接获得再现像的复振幅，提高了再现像的信噪比，避免了再现中的近似误差。

Based on the method that a rectangular function can be expanded into a sum of complex Gaussian functions with finite numbers, the propagation characteristics of a Gaussian beam passing through apertured spatial filter systems are analysed and the corresponding analytical formulae are obtained respectively.

根据矩形函数可以展开为有限复高斯函数之和的方法，从柯林斯衍射积分公式出发，对高斯光束通过受限空间滤波器传输特性进行分析，得到了相应的近似解析式。利用Matlab对其解析式进行数值模拟，得出一组直观的结果。

Stationary motions of the system were determined and periodic motions near them are conustructed using the Liapounov theorem of the holomorphic integral.

确认系统运动是稳定的，并通过Liapunov全纯积分定理，构建其近似的周期运动。

An inhomogeneous Benjamin-Davis-Ono-Burgers equation including topographic forcing and turbulent dissipation is derived in terms of the quasi-geostrophic vorticity equation, an approximate analytic solution of the BDO-Burgers equation with a small dissipation is obtained, the time variations of mass and energy of the algebraic solitary waves are discussed, and finally, the forced BDO-Burgers equation is integrated numerically and the numerical solutions are given for a given basic flow with a weak shear and a localized topographic forcing.

利用包括地形外源和湍流耗散的准地转涡度方程导出了包含强迫项和湍流耗散项的非齐次强迫BDO-Burgers方程，求出了小耗散存在情况下BDO-Burgers方程的近似解析解，讨论了代数孤立波的质量和能量的守恒关系，最后，对给定的弱切变基本气流和局地地形强迫，数值积分强迫BDO-Burgers方程，求得了不同参数下的数值解。

This process of approaching is crucial to the definition of the derivative and the integral in calculus

这个近似的过程影响到对导数的定义和微积分的积分

This process o f approaching is crucial to the de f inition o f the derivative and the integral in calculus

这个近似的过程影响到对导数的定义和微积分的积分

In light of the approximation of Muskingum flood calculation model,an improving model on average flow within prescribed time in flood calculation is presented using curve integral instead of general arithmetic mean.

针对马斯京根洪水演算模型的近似性问题，用曲线积分法改进了原模型中时段流量的简单算术平均值法，并利用连续性空间优化问题的蚁群算法对改进的马斯京根洪水演算模型进行参数最优估计，使演算流量更加接近实际。

The method that combines the effective - field renormalization group with the discretized path - integral representation is extenged to study phase transition of the transverse Ising model in a quantum - spin system on the plane triangular lattice.

将离散路径积分表示下的有效场重整化群技巧推广应用于平面三角晶格上量子自旋横向Ising模型的相变研究，在这个方法中，注意区分了两种具有相同配位数而不同几何构形的晶体，并且考虑了起伏的影响，在二阶累积量近似下，得到了接近于精确解的临界值。

According to the result, the confidence region of unknown parameters in single-index models is constructed. Finally, we consider the test of correlation and heterogeneity for hierarchical nonlinear mixed-effects models. According to Laplace approximation expansion of integrated log-quasilikelihood, a class of score test statistics is proposed. Under some very mild conditions, we prove the asymptotic distribution of the test statistics is a standard X~2-distribution. Through a Monte Carlo simulation study, the finite sample performance is examined.

最后，我们研究的第四个问题是分层非线性随机混合效应模型的相关性与异方差性检验问题，依据对数拟积分似然的Laplace近似展开提出了检验统计量，在一些正则条件下，得到了检验统计量的渐近分布是一个标准的χ~2-(来源：d7d7A65BC论文网www.abclunwen.com)分布，通过Monte Carlo模拟研究了其小样本的表现，实例验证了其实际应用。

The proposed scheme is developed using the local coordinate system based PML splitting equations and integral approaches of the PML equations under a discretization of triangular grid cells.

本方法的核心是建立局部坐标系下的分裂方程和基于积分近似的微分方程弱形式。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。