查询词典 geometric difference equation

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。

Several important nonlinear equations of mathematical physics such as φ4 equation, Klein-Gordon equation, the approximate equations of sine-Gordon equation and sinhGordon equation, Landau-Ginzburg-Higgs equation, Duffing equation, nonlinear telegraph equation are the special cases of the nonlinear wave equation presented in this paper.

几个有重要应用的非线性数学物理方程，如矿方程，Klein-Gordon方程，Sine-Gordon方程，及Sinh-Gordon方程的近似，Landau-Ginzburg-Higgs方程，Duffing方程，非线性电报方程等都可作为该方程的特殊情形得到相应的显式精确解，这里方法也可推广到n+1维空间情形。

The existing points and lines would form a closed geometric shape. If we put the new point Z outside the closed geometric shape at first and later then found that the point Z has neighboring relationship with the existing point A which is inside the closed geometric shape, we could not link point Z and A directly because that would bring line crossing. If we rearrange the point Z into the closed geometric shape, that also would cause a lot of work to do. With the help of Exclave, all problems could be solved easily. We use point X outside the closed geometric shape as the Exclave of the point A. Then the line between point Z and X could demonstrate the neighboring relationship of the point Z and A.

原有的各点和相邻线段往往会形成一个封闭的几何图形，如果我们把新增点 Z 设在原有的封闭几何图形外部，后来又发现该点 Z 和位于封闭几何图形内部的点 A 存在相邻关系，这时不能直接将两点连接因为那将产生交叉，而如果将点 Z 重新设在封闭图形内部也将导致大量的调整工作；此时借助外飞地的概念，可以轻松地解决上述问题，即在封闭几何图形外部设置点 X 作为点 A 的外飞地，两点使用同样的颜色，用点 Z 和点 X 的相邻线段表示点 Z 和点 A 之间的相邻关系。

Automated geometric theorem proving, as a byproduct of the completion of geometric theorems, is further developed into automated quantitative description of geometric relations. The recovery of the geometric meaning of this quantitative description leads to a natural extension of the geometric theorem.

几何定理的机器证明作为几何定理完全化的副产品，被发展成几何定理的关系定量化，这种量化的几何还原就是几何定理的自然推广。

The scale-type geometric wear-resistant structure surface is characterized in being made up of a base and the bionic geometric units on the surface. The bionic geometric structure unit is a scale-type structure distributed regularly on the surface of the base, and the distribution density is that: the ratio between the geometric projection area of the scale-type structure on the base surface and the surface area of the base formed by all the edge ends is 50-100%; the scale-type geometric structure unit has a symmetric hexagon shape on the surface; the sides L2/L1=1.0-2.0, L1: 1mm-50mm, and the internal angle Alpha is 120 degree -130 degree, the internal angle Beta is 100 degree -110 degree; the A-A section is subtriangular, and the B-B section is a trapezoid, the height H of the scale-type is 1-5mm.

本发明由基体和其表面上的仿生几何结构单元组成，仿生几何结构单元为在基体表面规律分布的鳞片型结构，鳞片型的分布密度为：其在基体表面上的几何投影面积之和与所有棱端围成的基体表面积之比为50-100％，鳞片型几何结构单元的表面形状为对称六边形结构：边长L2/L1＝1.0-2.0，L1：1mm-50mm，内角α为120°-130°，内角β为100°-110°，鳞片型的A-A截面为近似三角形，B-B截面为梯形，鳞片型的高度H为1-5mm。

To further investigate the influence of the Internet on the students, a further research is conducted by breaking the students into three groups -frequent Internet users, occasional Internet users and non-internet users. The result indicates that the self-harmony of frequent Internet users shows a sharp difference in terms of school and grade, the self and the unharmony of show a sharp difference in terms of school, grade and sex, and that the self-esteem and the two dimension - the flexibility and rigidity of self-harmony show no difference in terms of school, age and sex; the self-harmony and all dimensions of occasional Internet users show no significant difference, the self-esteem of occasional Internet users show no significant difference in terms of school and grade but show significant difference in terms of sex; the self-harmony and all dimensions of the non-Internet users show no significant difference, the self-esteem of the non-Internet users show no significant difference in terms of grade and sex, and the self-esteem of the non-Internet users show significant difference in terms of school.

为了进一步研究网络对学生的影响，又将学生分为经常上网、偶尔上网、不上网三类分别来研究：经常上网学生自我和谐在学校、年级都存在极显著差异，自我与经验的不和谐在学校、年级、性别存在极显著差异，自尊和自我和谐的灵活性和刻板性两个维度在学校、年龄、性别都没有差异；偶尔上网学生，自我和谐及各维度都不存在显著性差异，自尊在学校和年级不存在显著性差异，在性别上有显著性差异；不上网学生自我和谐及各维度都不存在显著性差异，自尊在年级和性别不存在显著性差异，自尊在学校上有显著性差异。

Establish the steady-state and transient model using the three hydrodynamics equations (Continuity equation, Momentum equation and Energy equation). By comparing different state equation, it selects the BWRS state equation which is considered the most accurate state equation in current natural gas measurement. It calculates compression factor, density and other Thermal parameters based on BWRS state equation. In Numerical solution of the steady-state and transient model, compression factor, friction coefficient and all the other Thermal parameters are recalculated in each small time step to reduce the numerical calculation error.

在稳态模型的建立上，利用流体力学三大方程(连续性方程、运动方程和能量方程)，通过比较不同的状态方程选用了目前被认为最精确的用于天然气计量的BWRS状态方程，并以此方程为基础进行压缩因子、密度等热物性参数的计算；在稳态模型的求解上，选用容易计算，精度较高的标准型龙格—库塔(Runge-Kutta)法进行数值求解，并且在迭代过程的每一小步都重新计算燃气的压缩因子，摩阻系数等所有的计算参数，以减少数值计算的误差。

Chapter 2 is devoted to study of exact solutions of the nonlinear evolution equations. Using solutions of a Bernoulli equation instead of tanh in tanh-function method we find some more general solutions of the KdV-Burgers-Kuramoto equation , and by using the nonlinear telegraph equation we show that there are many different choices on its balancing number m and the power n of the nonlinear term in Bernoulli equation by which we can recover the previously known solutions and also can derive new square root type solitary wave solutions. Exact solitary wave solutions for a surface wave equation are obtained by means of the homogeneous balance method. We also present an approach for constructing the solitary wave solutions and non-solitary wave solutions of the nonlinear evolution equations by using the homogeneous balance method directly, which is also used to find the steady state solutions, solitary wave solutions and the non-solitary wave solutions of the 2+1 dimensional dispersive long wave equations. The soliton-like solutions of the BLMP equation and the 2+1 dimensional breaking soliton equation are found by use of the symbolic-computation-based Method.

第二章中研究了非线性发展方程的精确解：用双曲正切函数法中的双曲正切函数换为Bernoulli方程的解的方法而给出KdV-Burgers-Kuramoto方程的精确解并用非线性电波方程为例说明了平衡数m和Bernoulli方程中非线性项的次数n有着多种选择的可能，它不但使我们能找到已知解而且也能找出新的根式孤立波解；用齐次平衡法给出一个曲面波方程的精确孤立波解，并提出直接用齐次平衡法寻找非线性发展方程的孤立波解、非孤立波解的方法，作为应用给出2+1维色散长波方程组等的定态解、孤立波解、非孤立波解等；用Symbolic-computation-basedMethod获得BLMP方程和2+1维破裂孤子方程的类孤子解；提出sine-Gordon型方程的直接求解方法，并获得sine-Gordon方程、双sine-Gordon方程、sinh-Gordon方程、MKdV-sine-Gordon方程和Born-Infeld方程等的精确孤立波解。

The asymptotical properties of KdV equation and KP equation exhibit the soliton behavior when some conditions are satisfied, and in some cases the parameter matrices describing the interaction between two solutions is quite simple. Two kinds of solutions of the second coupled equations of AKNS hierarchy are provided and applied to NLS equation. A systemical way of construction of special solutions is also tried for DS equation. Most of the results on a scalar equation can often be directly generalized to some matrix equation, and the difference between the ω in scalar form and ω in matrix form lies only in the replacement of vector p, q by matrices p, q.

对KdV方程和KP方程渐近性质的讨论显现出解在一定条件下的孤子特性，从而使得一些情形下，同类解的相互作用体现在参数矩阵上变的较简单；我们给出了AKNS方程的两类不同解，并约化到NLS；对DS方程，我们从另一个方面初步探讨了形式化推导矩阵方程特解的方法；把这些有关标量ω的结果推广到ω为矩阵上往往只要把p，q变为矩阵即可，进而可以再推广到方程组上。

Thirdly, according to the development of the frozen soil, the coupling model of single freezing pipe of axial symmetry of temperature field, stress field and moisture migration is put forward firstly. Then, by means of the progressing principle of potential field, the coupling model of temperature field, stress field and moisture migration which is under the condition of the multi-freezing pipes is extended. At last, the energy balance equation, stress balance equation, quality balance equation, geometric equation, physical equation, initial and boundary conditions etc are adopted to give the analytic solution to the problem of plane axial symmetry of single freezing pipe.

第三，在对室内试验和现场实测结果研究的基础上，分析了土体冻结过程中温度场、应力场、水分场耦合原理，并按照冻土体形成发展过程，首先建立了单一冷源冻结轴对称温度、应力、水分场耦合模型；接着利用势场的迭加原理，将单一冷源情况的三场耦合问题推广到多冷源情况的三场耦合；最后根据能量守恒平衡方程、应力平衡方程、质量守恒平衡方程、几何方程、物理方程、初始及边界条件，解出了单一冷源平面轴对称问题的解析解。

Chinese traditional virtue is humility and wariness,the compliment and praise to the others should be declination

中国人的传统美德是谦虚谨慎，对别人的恭维和夸奖应是推辞。如

We bought this house on the never-never.

我们以分期付款的方式买下这座房子。