查询词典 numerical

In this paper, the main parameters of poison gas's numerical simulation are analyzed on the basis of studying of the numerical simulation and dynamic emulation of poison gas leakage and diffusion possibly occurring in the destructive earthquake.

本文在破坏性地震中可能发生的次生毒气泄漏与扩散灾害的数值模拟与动态仿真研究的基础上，分析了影响毒气扩散的主要参数。

After analyzing the relationship between the amount of atmospheric water vapor and ground vapor pressure, precipitable water vapor retrieved by GPS with those based on numerical models are compared in order to assess precision of the results based on numerical models.

在讨论了GPS遥感结果与地面水汽压关系的基础上，通过比较GPS遥感结果与几种国内外常用的利用地面湿度参量计算总水汽量方法的结果，评价了这些方法的精度及在实际应用中的可行性。

Based on the theory of contact dynamics, the dynamic model with clearances of sizing press roll was established using the method of numerical simulation. The paper studied the effect of clearances on contact force inner Mechanism joints detailedly by the method of numerical integration of fix step length four orders Runge-Kutta.

基于接触动力学的理论，利用数值模拟的手段建立了调宽机含间隙的动力学数学模型，采用定步长四阶Runge-Kutta数值积分的方法，详细研究了运动副内间隙对接触力的影响规律。

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

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。

One of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control Controlling a machine tool using a punched tape or stored program is known as numerical control.

在先进制造技术领域的最根本的观念之一是数控机床控制用穿孔纸带或存储方案被称为数控的。

In order to control the propagation of errors and enhance the accuracy of numerical solution, the wilson-θ method is modified and the numerical stability of modified wilson-θ method is analyzed.

为有效控制误差的传递，提高计算精度，对Wilson-θ法进行改进并分析了改进Wilson-θ法的稳定性。

On the basis of the casing damage mechanism study,the fluid pressure field numerical modeling and finite element numerical modeling under solid mechanical propertied and fluid-solid coupling conditions were introduced.

并进行了大量的现场测试，获取了大量准确的资料，为深化套损机理研究奠定了基础和提拱了支撑；五是开展了大量的室内和现场试验。

Therefore, it is always reasonable that the numerical rank be regarded as the rank of a matrix in the process of numerical computations.

从而在数值计算过程中，认为矩阵的秩就是其数值秩总是合理的。

Do some tentative analysis of the tunnel lining by numerical manifold method. the idea is given that combining regular mesh with finite element mesh and using low-order and high-order cover displacement function in numerical manifold method, it make preprocess and program analysis, precision and efficiency for coordination.

4利用数值流形方法对隧道工程中衬砌结构进行了尝试性的分析，提出了结合规则网格和有限网格并行、高低阶覆盖位移函数混合计算的思想，以达到前处理和程序计算、计算效率和求解精度的协调。

We are in a real jam.

我们的麻烦大了。

Hey, it's Ahmet from India, that foreign exchange guy.

看，那是印度的阿曼特，国际交换生