查询词典 first order

Within this context, four specific areas are addressed:(1) By means of finite integration technique, a new kind of the first order partial difference equation is derived from the original disperse transmission line equation of the uniform waveguide's. As it is the kind of one dimension Dirichlet's boundary problem, it is convenient for us to solve this equation from the leapfrog scheme. Because computation is carried out in one dimension, both high calculation efficiency and precision have been obtained in this method. Meanwhile, this method provide us a different selection to simulate the transient response of waveguide with non-simplical, for examples cylinder and elliptic waveguide, and avoid solving the second order equation, or using finite difference time domain to simulate a three dimension problem, sometimes the latter precision is not satisfied with the need, or low efficiency.

在这一研究内容下，主要研究四个方面的问题：(1)在完成金属波导传输线方程时域形式的基础之上，应用有限积分技术，把波导特征模式的色散传输线方程，化简为一组新的一阶偏微分方程组，该边值问题属一维Dirichlet边值问题，从而便于用蛙跳格式求解，由于是在一维中计算，该方法具有很高计算效率和精度，从而避免了以往为得到金属波导中特征模的时域响应特性，须要求解二阶方程，或用时域有限差分方法求解三维问题的方法，对于后者来说，计算有时是不准确的，或是很耗时的例如计算诸如圆波导、椭圆波导等其它复杂形状的波导。

The non-relativistic energies and wave functions were determined by Rayleigh-Ritz method. The relativistic effects, including the correction to kinetic energy, the electron-electron contact term, and the orbit-orbit interaction, Darwin term, and mass-polarization effect on the energies were calculated by using first-order perturbation theory. In order to obtain a more accurate result for the larger Z system, the quantum-electrodynamics correction should be included. This correction to energy can be evaluated for the valence electron by using a hydrogenic formula with an effective nuclear charge, Z. The ionization potential, the excitation energies and the fine structure split-tings for a lithium-like ion with higher nuclear charge (Z=26) were calculated.

非相对论能量用Rayleigh-Ritz变分法确定，包括动能修正、电子—电子接触项、轨道—轨道相互作用项以及Darwin项的相对论修正和质量极化项由全实加关联波函数的一阶微扰给出，量子电动力学修正由有效核电荷方法和类氢公式计算；给出了较高核电荷(Z=26)类锂体系1s^2nl组态的电离能、激发能和1s^2np组态的精细结构劈裂。

This paper points out that as the peak of the first order wind spectrum situated at a region of very low frequency, the contribution of the sum_frequency part to the second order wind spectrum is no longer negligible.

本文指出，由于风速谱与波浪谱不同，它的能量峰值位于极低频率处，因此二阶风速谱中和频项的贡献不能忽略，为此本文首先导出了保留和频项情况下的二阶风速谱表达式，并将和频项与差频项在数值上作了比较。

The method of calculating the internal force envelope of cable-stayed bridge by first order theory, multiplied by a modification factor for considering second order effect, is not adequate enough.

用一阶理论的内力包络图值乘以近似二阶增大系数的方法来设计斜拉桥的主梁尚欠合理。

In order to compute the failure probability of structural systems for stability of gravity retaining walls, firstly, two performance functions against overturning and sliding of gravity retaining walls were established. Then, the first order second moment theory in structural reliability analysis, i.e., the checking point method was introduced to compute the two failure modes respectively, and two corresponding reliability indexes could be obtained.

为了计算重力式挡土墙稳定性的结构体系失效概率，首先分别建立重力式挡土墙结构抗倾覆稳定性和抗滑移稳定性的功能函数，然后引入结构可靠度分析一次二阶矩法中的验算点法分别对两种失效模式进行计算，得出两个相应的可靠度指标。

First order coefficient of the phase error function can be estimated by sensor-based motion compensation. Second or higher order term of phase error function could be estimated and cancelled by autofocus technique.

传统由感测器执行之运动补偿功能只能测量到相位的一次项系数，如果加上自动聚焦法，则可以将二阶以上的误差项消除。

Of a high order , of the highest/first order

高质量的；高品质的；一流的

Put forward a new method by transforming the second-order hyperbolic equationinto a first-order system of equations and derived the H_0~1 -norm and the L~2 -norm error estimates.

12提出一种新方法，通过转化双曲型方程中二阶时间导数项得到关于一阶时间导数的耦合方程组，然后进行离散，得到一个两层交替方向有限元格式，并得到H_0~1-模和L~2-模误差估计。

However, most of the existing projection methods are only first order or incompletely second order accuracy in time.

目前，绝大多数不可压缩数值方法，在时间方向上都仅仅停留在一阶或不完全的二阶精度。

Based on the interstices of yams, warp and weft crossed areas are located, and four textures of these areas are obtained by first-order and second-order statistics.

基于纱线间隙和经纬纱交叉区的存在，通过一阶和二阶的统计量可获取4种区域结构特征。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。