second approximation

A new second order nonconforming finite element approximation to hyperbolic equation

双曲型方程的一个新的二阶非协调有限元逼近

Electron scattering from argon in laser field is investigated employing the second Born approximation. The absolute differential cross section of e Ar scattering with one, two, and three photon exchange at scatering angles 1 °~ 26 ° are calculated.

利用第二玻恩近似方法（SBA）对激光场中eAr的散射进行了研究，计算了散射角为1°～26°，交换多个光子的微分散射截面。

The problems on calculating of the second and the third cosmic velocity are analyzed. The third cosmic velocity of 13.6 km · s-1 is obtained in the adiabatic approximation.

本文分析了第二、第三宇宙速度计算中存在的问题，导出绝热近似下第三宇宙速度的数值为13.6km/s。

The result of the second approximation with ncluded may be used for the calculation within ordinary accuracies.

保留项的二阶计算结果可用于一般精度的计算。

By using the partial order method and some new comparison results, the maximal or minimal solutions, the unique solution and the iterative approximation of solutions of the initial value problem for nonlinear second order integro-differential equations in Banach spaces are investigated.

利用半序方法和新的比较结果，研究了Banach空间中二阶积-微分方程初值问题的最大解、最小解、解的存在与相应解的迭代逼近。

Through second-order perturbation approximation and modal expansion approach, the second-harmonic generation of a primary Lamb wave propagating in layered structures has been analyzed, and the general solution to second-harmonic displacement fields has been obtained.

采用二阶微扰近似和模式展开方法，对分层结构中兰姆波的二次谐波发生问题进行了深入研究，得到了二次谐波声场的一般表达式。

For two-dimensional Navier-Stokes equation, the second order implicit legendre approximation with high-accuracy was established. This approximation has two order accuracy in time direction, and spectral accuracy in space direction, and keeps the conservation of the dispersed energy.

针对二维Navier-Stokes方程建立了高精度的二阶隐的Legendre谱格式，该格式在时间方向具有二阶精度，在空间方向具有谱精度，且保持了离散能量的守恒性。

Based on curvilinear trajectory equations, the geometrical aberrations and their coefficients with second order approximation have been discussed, and the computational form also given in the paper.

分析了旋塞阀旋塞体与塞子锥面因加工方法与工艺不当而产生的几何偏差，给出了消除锥面加工产生偏差的几种方法。

Second-order approximation of the function of the separation for the dynamics of the Josephson junction

动力系Josephson结的距离函数的二阶近似

The field equations containing higher than second derivatives of the metric are obtained by adding the squared Weyl conformal Curvature term to the action for the Einstein theory of gravity. The Newtonian limit is given in first approximation and some new results are discussed.

在Einstein引力作用量中引入Wevl张量的平方项，得到有度规张量高阶导数项的引力场方程，考虑其弱场线性近似解，给出了牛顿极限，并讨论了某些新结果。

In this paper, using the PLK method and reductive perturbation method, we obtained the second approximation to cnoidal waves at the free surface and interface for the two-fluid system considered in [ 1].

本文考虑[1]中所建立的模式，采用约化摄动法及PLK方法，求得了自由面及界面上的二阶椭圆余弦波。