结构方程

And combining finite element method and periodic boundary conditions,this article has provided the solution process for asymptotic homogenization equation and the predicting effective mechanics properties method in engineering.

本文利用渐进均匀化理论，详细叙述了求解具有周期性细观单元结构的复合材料有效力学性能的方法，并结合有限元理论和周期性边界条件，给出了求解渐进均匀化方程的过程，为实际工程问题提供了预测材料力学性能的方法。

KdV equation can bedescribed in the language of Poisson bracket,so we can exploit its bracket struc-ture to design numerical approximations.

KdV方程能用Poisson括弧的语言来描述，因此我们可以利用它的括弧结构设计数值逼近。

Within algebraic geometry is the description of geometric objects as solution sets of polynomial equations, combining the concepts of quantity and space, and also the study of topological groups , which combine structure and space.

在代数几何里，把几何对象描述成多项式方程的解集，结合数量和空间的概念；也研究拓扑群，结合了结构和空间。

L , and position vector, rr .

和位置矢量rr ，通用的电场积分方程可以应用到任意线结构天线。

The mathematical models of the dynamics of the mass transfer based on the Nernst-Planck equation were established from which it is found that the different characteristics of the water decomposition between the cation and the anion exchange membranes or resins, is owing to the different potential gradient on the two kind of ion-exchange interfaces, which is further because of the difference between the structure and performance of the different membranes or resins, and is also because of the difference between transfer numbers of cation and anion ions.

根据所建立的传质数学模型方程获知在阴阳膜／树脂表面与水接触的界面层中发生的水解离的差异性，是在于离子交换界面电势梯度的差异，而这种差异又与膜与树脂的结构、性能以及阴阳离子在水溶液中的迁移数的差异有关。

To get knowledge on Kuroshio large scale circulation and how the Kuroshio affects adjcent area climate, a three-dimension primitive equation ocean model MITgcm was used to simulate the kuroshio＇s climatological pattern.

为了掌握黑潮的大范围流动结构以及它对气候的影响，利用三维原始方程模式MITgcm计算了西北太平洋海区的多年平均流态。

Thus a simple method is proposed for determining the value of reference node coordinate, that is to derive the cross-point of coordinate equation of Y, which represents the principal inertia plane and the one perpendicular to the other plane.

为此提出了一种参考节点坐标值的简易确定方法，即通过求解代表主惯性平面和与主惯性平面正交的另一平面同Y轴的交点坐标方程，根据抽油机支架上角钢的结构方式，取代数值较大的一个即可确定参考节点的位置。

It introduced fundamental functions of elastic mechnics, elastic FEM, principle of virtual displacement and the creation of structure equilibrum equation.

第二章 有限单元法原理部分，在该部分中概要介绍了弹性连续体的有限元方法，虚位移原理和结构平衡方程的建立。

Based on the variational principle of virtual voltage and virtual displacement derived in this thesis and the classical theory of linear laminated plates, and by using the constitutive equations of elastic piezoelectric materials, and the DKQ quadrilateral plate bending element, the finite element modeling for the fabric reinforced laminated plates with nonlinear voltage-electric strain relationship of piezoelectric actuators has been established for the first time in this thesis. And the expressions for the electric loadings with obvious mechanical meaning and convenient for computation are established, which can be used to the deformation analysis of laminated plates with piezoelectric actuators under specified voltages.

以本文直接导出的压电结构的虚电势—虚位移变分原理为基础，依据经典线性层合板理论和压电弹性体的本构方程，采用基于离散法线假设的DKQ四结点任意四边形薄板弯曲单元，首次建立了考虑非线性电压—电应变关系的含压电致动器的纤维增强型层合板的有限元分析模型，并推导建立了力学意义明确、便于计算的电荷载表达式，可用于指定电压条件下纤维增强型叠层合成板的变形分析。

This paper investigates the several key problems in calculating reliablity with direct numerical integration and completes a direct numerical integration program, and conducts some parameter analyses.

在计算过程中发现JC法在计算一些比较复杂的结构问题时有一定的局限性，特别是在计算非线性的极限状态方程和解决多模态相关问题的可靠性时，存在着较大的误差。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。