近似方法

The annulus model captures the key features of rotating convection in full spherical geometry and has been widely employed to study convection, magnetoconvection and dynamos in planetary systems, usually in connection with the small-gap approximation neglecting the effect of azimuthal curvature of the annulus.

圆环模型被广泛用来研究行星系统的对流，磁对流和发电机。通常在这些研究中用到了小间隙的近似，忽略了圆环的环向曲率效应。我们这一工作用数值模拟方法解完全的非线性对流方程组来研究有限间隙的旋转圆环中的非线性对流。

The results indicate that for both NaCl and CsCl structure ferrimagnets the results of spin wave spectra and mean values of spin vector in Z-direction are strongly different from that of the ferrimagnets with the nearest-neighbor interactions only.

本文在无规相近似下，利用格林函数方法，研究了具有最近邻和次近邻相互作用的亚铁磁体中的自旋波。

After standardizing transform of fluctuant component series of size curves of cocoon filaments, the simulation method of the series is brought forward by means of auto-regressive model of stationary time series. The simulation and analysis are carried out.

茧丝纤度曲线波动分量通过标准化变换处理后，近似看作平稳时间序列，利用平稳时间序列的自回归模型，给出了这种时间序列的模拟方法。

Therefore, basic methodologies for stochastic seismic and filtering responses of nonlinear structure are studied, the approximate solution methodologies and their practical applications are investigated in the dissertation employing equivalent linearization and moment equations method based on FPK equations and Ito stochastic differential equations. The research works are mainly concerned with the following aspects:Firstly, the differential expression of bilinear hysteretic is studied and a new differential expression is developed, then they are demonstrated.

因此，本文基于FPK方程和伊藤随机微分方程，研究了滞后结构物的随机地震反应和随机滤波问题的基本方法，并利用等效线性化法和矩方程法，研究了非线性结构随机地震反应分析和随机滤波分析的近似解法及它们的工程应用。

To be the heart of the dissertation, the fundamental coupling equations of multi-conductor system with both parallel and cross conductors existed are drawn by using secondary field theory. In addition to the strict solution, a kind of approximate solution, namely, equivalent transmission line equation is presented.

作为本论文的核心，重点研究了地下存在受扰多导体时地下场的分布情况，利用二次场的方法，得到了地下平行、交越多导体系统的基本耦合方程，除给出该方程的严格解外，还给出了一种近似解法——等效传输线方程解法。

Then the problem is reduced to less degrees of freedom to solve nonlinear equations by the modal synthesis method.To verify the successfulness of this method,an example is given.

利用非线性振动理论的平均方法，求得经模态综合法降维后系统方程的近似解析解。

The global and superlinear convergence results of the new algorithm are established.

该算法中我们允许使用非精确的方法近似求解信赖域子问题。

The error caused by supposal are corrected and it shows idea of roseatch on physics method and resolution to complex actual problems .

最后针对原有假设引起结果的近似进行修正，从中体现物理学方法研究和处理复杂实际问题的思想

For the sweepback airfoil,the paper constructs its approximation models of structure disciplinary and aerodynamic disciplinary.

结果表明，用Kriging方法构造的近似模型精度较高，而且比较稳健。

An engineering approximately design method-equivlent circuit isalso introduced by equilent circuit of waveguide ET-junction and principle of symmetry and of multiplication of matrix.

本文同时依据对称性原理、ET接头的等效电路及传递矩阵的乘积原理建立了波导谐波滤波器的近似工程设计方法——等效电路法，指出等效电路法虽然精度有限、但计算时间很快，可以进行基、谐波全频段分析。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。