查询词典 characteristic equation

This section presents two kinds of characteristic schemes, one is the natural use of the usual backward Euler characteristic difference scheme ( [60] ) onto the triangular mesh, the other replaces the backward Euler's method by modified Euler formula to approximate the characteristic differential equation, so that the discretization for characteristic curve can get up to second order accuracy.

本节给出了两种三角形网格上的特征差分格式，第一种是通常的向后Euler型特征差分格式（[60]）在三角形网格上的自然运用，第二种采用§3.3、§3.4的离散思想，使用改进的Euler公式代替向后Euler公式来近似特征微分方程，使其对特征线的离散达到了二阶精度。

The basic concept in these sections is replacing backward Euler's method by modified backward Eulers's method to approximate the characteristic differential equation and discretizing the convection-diffusion equation at the middle point of the approximate characteristic curve, which will make the convective term get up to second order accuracy.

这三节的基本离散方法是用改进的Euler公式代替向后Euler公式来近似特征微分方程，并且将近似特征线的中点作为离散节点，使得对流项的离散精度提高到二阶，对于扩散项，将其转移到待求时间层进行离散。

In addition, the voltage-current characteristic of linear resistive components is the general solution of Clairaut equation, and the voltage-current characteristic of non- linear components is the singular solution of Clairaut equation.

论文摘要：本文讨论了任意伏安特性电阻元件满足的基本微分方程以及非线性电路的功率匹配问题的几个定理，指出任意伏安特性电阻元件均满足非线性一阶的clairaut方程，并且，线性电阻元件的伏安特性是clairaut 方程通解，而非线性电阻元件的伏安特性是clairaut 方程的奇解。

This paper starts from the rules of Coulomb's law, Ampere's power Law and the D'Alembert equation, hai Muhuo equation and so on, reveals the mechanical essence and divergent characteristic of electromagnetic interaction; it follows the rule shown in d'Alembert equation and transmits in the form of electromagnetic waves and spherical waves in electromagnetic field.

文章从库仑定律、安培力定律和达朗贝尔方程、亥姆霍次方程等规律出发，揭示了电磁相互作用的力学实质和发散特性；它遵循达朗贝尔方程所示的规律，以电磁波的形式和球面波的方式在电磁场中传递。

The traffic momentum differential equation and Euler's equation for the ramp junction is founded by means of differential calculus in this paper,the traffic momentum differential coupled equation is solved by characteristic curve method,two groups of characteristic curves and corresponding related equation in high speedstates and low speedstates are presented.

采用特征线法对运动微分方程组进行分析求解，在高速低密度区和低速高密度区分别得到了两组特征线和对应的特征关系式。

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。

The Routh criterion is a method for determining continuous system stability, for systems with an nth-order characteristic equation of the form

劳斯判据是用来判断连续系统的稳定性的，如系统具有如下n阶特征方程形式

Since the roots of the characteristic equation of the digital control system must stay inside the unit circle =1 in the z-plane for the overall system to be asymptotically stable,we see that the second-order digital control system can be unstable for large values of T.

由于基层的特征方程的数字控制系统必须留在单位内循环= 1中的Z -飞机的整体系统是渐近稳定的，我们看到，二阶数字控制系统可为大型值不稳定普通应用评委的稳定性试验的特征方程的均衡器。

The thermodynamics principle of dyeing of modified flax fabric has been studied in the aspects of adsorption isotherm, dying appetency, substantivity and saturation value and so on. The results indicate that dyeing adsorption isotherm of modified flax fabric belongs to the characteristic equation curve of Langmiur, which is according to the mechanism of electric adsorption.

从阴离子染料上染改性亚麻织物的吸附等温线、染色亲和力、直接性、染色饱和值几个方面研究了改性亚麻织物染色的热力学原理，结果表明：改性亚麻织物染色的等温吸附线属于Langmiur方程的特征曲线，即按电荷吸附机理进行。

A calculating formula for rotational speed derives from movement characteristic equation of one bank planet gear mechanism.

以单排行星齿轮机构一般运动规律的特性方程式为基础，导出了输出轴转速的计算公式。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。