结构方程

In this paper, inverse scattering series method is based on wave equation and Born series, multiples are predicted and removed by constructing a subseries corresponding to surface-related multiples. This method does not need any subsurface information and is suitable for different kinds of complex structures.

本文研究的逆散射级数法以波动方程和Born级数为基础，构造一个与自由表面多次波相关的子序列来预测并消除多次波，该方法不需要知道地下的速度结构信息，适用于各种复杂的地下情况。

Then, the equation of quantitative structure-activity relationship was effectively established with four descriptors like the molecular volume V(subscript m, order zero chi index, sum of the product of solvent-accessible surface area multiplied by partial charge for all positively charged atoms (Jurs-PPSA-3), and molecular surface area.

QSAR方程含分子体积V、分子分支度指数CHI-0、分子中带正电荷原子的溶剂可积面积与其所带电荷之积的加和值Jurs-PPSA-3以及分子表面积S4个结构描述符。

The solution of this system of differential equations gives the displacements and internal forces.

通过对微分方程的求解，计算其整体位移及结构内力。

To overcome the difficulties and drawbacks in modeling the dynamic systems by using traditional methods, a hybrid evolutionary modeling algorithm is proposed to model the dynamic system with a system of ordinary differential equations whose main idea is to embed genetic algorithm in genetic programming where GP is employed to optimize the structure of a model, and GA is employed to optimize the parameters of a model.

针对采用传统方法解决动态系统的微分方程建模问题所遇到的困难和存在的不足，文中设计了将遗传程序设计与遗传算法相嵌套的混合演化建模算法，以遗传程序设计优化模型结构，以遗传算法优化模型参数，成功地实现了动态系统的常微分方程组建模过程自动化。

The expression of tangential velocity in all space was also given.

6通过N-S方程推导了切向速度的公式，证实是一种组合涡的结构，并获得了全空间的切向速度表达式。

The Taylor expansion stochastic finite element method is extended for the structure vibration analysis.

在材料性能特性被看成随机的情况下，结构振动方程先用Newmark法转化为静力问题。

This article uses Laplace equation, separating tetrahedron as various units and the using the appropriate form function to discrete the complex structure, surface and its environment.

采用电化学场中的拉普拉斯方程，使用四节点四面体和合适的形状函数对水室表层和复杂结构体系周围场域进行离散。

Topological indexes of A , B , C and D were all obtained from the different combination of topological vertex degree. A QSAR equation for this series of compounds was established based on the multi-linear regression method and a new group of autocorrelation topological indexes. The results showed that the biological activity is linearly correlated with the volume and branching size of the quinclorac derivatives. Finally, new herbicide was designed based on all QSAR results.

针对应用经典结构参数和量子化学参数得出的结果不够理想的问题，对点价自相关拓扑指数进行了研究，建立了一组新型的点价自相关拓扑指数A、B、C、D；首次将该指数用于除草剂氯喹酸酯类化合物的定量构效关系研究中，建立了很好的定量构效关系方程，综合分析所有的QSAR结果设计出了潜在的新型除草剂氯喹酸烯丙酯。

Traditional KF is utilized to identify structural parameters by transformation from dynamic system differential equation to state space, and combining structural parameters and responses in system state vectors in this dissertation.

利用传统KF将动力学系统的运动微分方程转换到状态空间中，然后将待识别的参数同结构的响应—并作为系统的状态向量进行识别。

By constructing the Lyapunov function with a special structure, prior estimate and the solution of ordinary different equation, we prove the main result, i.e., the trivial solution has global asymptotic stable behavior.

构造具有特殊结构的Lyapunov函数，并通过解的先验估计和常微分方程的定解，证明了主要结论，即平凡解全局渐近稳定。

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％。