查询词典 equation of a curve

In this paper, a region approximation idea that means using a "fat curve" with a width to approximate the offset curve is proposed, and a complete set of algorithms to approximate offset curve using disk Bézier curve are given and implemented. In the algorithms, the optimal and uniform approximate curve of the offset curve as the central curve of the Disk Bézier curve is found by using Remez method, and then the upper optimal and uniform approximation principle is proposed to compute the error radius function of the Disk Bézier curve. Thus, the whole Disk Bézier curve can be obtained. In the end of this paper, the approximate effect of the Disk Bézier curve is not only analyzed and assessed, but also some specific examples are provided.

提出用一条带宽度的"胖曲线"来逼近上述等距曲线的区域逼近思想，并建立与实现了圆域Bézier曲线等距逼近的整套算法，包括应用Remez方法求出等距曲线的最佳一致逼近曲线作为圆域Bézier曲线的中心曲线，提出上控最佳一致逼近的原理求出圆域Bézier曲线的误差半径函数，以及确定整条圆域Bézier曲线，最后还对该圆域Bézier逼近的效果做了分析和考核，并给出了一些具体实例。

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 establishes cubic spline function, analyzes subsection curve function and curve slope and curvature, at last decides to place the curve especial points which can be obtain easement curve length and other line parameters, such as the ZH point (end of line and beginning of transition curve), the HY point (end of transition curve and beginning of circular curve), the QZ point, the YH point (end of circular curve and beginning of transition curve), the HZ point (end of transition curve and beginning of line).

针对公路平面线形的8种组合类型，其线形元素特征则由最基本的直线、圆曲线、缓和曲线组成的特点，解析三次样条函数模型，得分段曲线函数、曲线斜率、曲率，从而确定曲线特征点（直缓ZH点、缓圆HY点、曲中QZ点、圆缓YH点、缓直HZ点）位置，进而得到曲线缓和曲线长度及其他线形参数。

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。

Finally it analyzes the feasibility that using hydromechanics to analyze traffic flow by contrasting various characters between traffic flow and fluid flow. It analyzes influence of road alignment to basic expressway segment capacity by hydromechanics, and obtains viscous resistance and viscous movement differential equation when the vehicle drives on circular curve segment of expressway. And it infers that viscous resistance is correlated with sideway force coefficient, slope of crown and radius of circular curve. Radius of circular curve, sideway force coefficient and slope of crown are bigger, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on nearside lane of circular curve; but radius of circular curve and sideway force coefficient are bigger, slope of crown is smaller, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on fast lane of circular curve.

最后通过对比交通流与流体流的相似性，运用流体力学分析了道路线形对快速路基本路段通行能力的影响，求出了车辆在曲线路段的粘性阻力，建立了车辆在曲线路段的粘性运动微分方程，并由此推知，粘性阻力与横向力系数、路拱横坡度和圆曲线半径都有关系，当车辆在圆曲线外侧车道上行驶时，圆曲线半径、横向力系数和路拱横坡度越大，粘性阻力就越小，对道路的通行能力影响就越小；而当车辆在圆曲线内侧车道上行驶时，圆曲线半径和横向力系数越大，路拱横坡度越小，粘性阻力就越小，对道路的通行能力影响就越小。

Based on the theories of rheology, Non-Newtonian Fluid Mechanics, petroleum chemistry, crystallography and pipeline technology etc. and sampling Huabei crudes, experimental indexes and programmes are drew out, integrating the oil properties and parameter analysis; in terms of the macro analysis of continuum mechanics, substantial experiments are conducted with HAAKE RS600 rotational rheometer and the rheological equation as well as the viscosity-temperature equation are further developed with tested rhrogramme and viscosity-temperature curve, respectively. Beased on the researches on thixotropic mechanism and thixotropy fluid property, hysteresis loop curve, structure failure and viscosity build-up curve as well as shear stress decrement curve for one type oil are first present in this paper. According to the theoretical researches and testing results, a novel thixotropy equation with τ=τ_∞e~ pattern, which is of hi-accuracy, few parameter and simplicity, is developed. Considering the influence of various parameters on rheological behaviour, depressant adding condition is optimized and experimental evaluation on BEM-5P is conducted, which further unrip its mechanism on the Huabei crude. A corresponding viable pipe transportion programmel is also recommended.

本文基于原油流变学、非牛顿流体力学、石油化学、结晶学、原油管输工艺学等理论，以华北原油为研究对象，结合原油物性及实验影响因素分析，制定出实验研究的评价指标及实验方案；从连续介质力学宏观分析的角度，利用HAAKE RS600高端旋转流变仪开展了大量的室内实验，并运用微观研究方法，测定了油样的流变曲线和粘温曲线，建立了流变方程和粘温方程；通过对触变性机理和触变性流体特征的研究，首次对华北原油测定出滞回环曲线、结构破坏与恢复粘时曲线、剪切应力裂降过程曲线，并在理论研究和实验结果的基础之上，建立了能定量描述含蜡原油剪切应力裂降过程的新型三参数触变模式τ=τ_∞e~b/(t+c，该模型具有精度高、参数少、实验简便且适用性强的特点；通过对含蜡原油流变性的影响因素理论研究，开展了加剂条件优选及BEM-5P降凝剂室内评价实验，进一步揭示了降凝剂对华北原油作用机理，在此基础之上，提出了华北原油管输的可行性方案。

Results There was a linear trend between logarithmic X and Y, the equation of logarithmic curve was able to be fitted, There was a linear trend between logarithmic Y and X, the equation of exponential curve was able to be fitted, There was a linear trend between logarithmic X and logarithmic Y, the equation of power curve can be fitted. There is a parabola pattern between X and Y, the equation of parabola was able to be fitted.

结果 X取自然对数与Y作散点图有直线趋势，拟合对数曲线方程；Y取自然对数与X作散点图有直线趋势，拟合指数曲线方程；X取自然对数与Y取自然对数作散点图有直线趋势，拟合幂函数曲线方程；原始数据X和Y成抛物线关系，拟合抛物线方程。

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。

Result: Scoliosis was identified in 58 cases with Marfan syndrome (38 males and 20 females), the prevalence rate was 42.03%, male-female sex ratio was 1.18:1, 6 cases were in younger than 10-year-old group. 12 cases were in 11~20-year-old group, 19 cases were in 21~30-year-old group, 11 cases were in 31~40-year-old group, 7 cases were in 41~50-year-old group, 3 cases were in 51~60-year-old group. Mean magnitude of Cobb angle in coronal plane was 26.8°±27.8°, the types of scoliosis curve included thoracic curve (36 cases), thoracolumbar curve (11 cases), lumbar curve (2 cases), double curve (6 cases) and triple curve (3 cases), apex vertebraes were convex to the right side among single curves in 38 cases while 11 cases were convex to the left side. Mean magnitude of kyphosis in sagittal plane was 14.3°±13.2°, 5 patients had thoracic lordosis and 40 patients had hypokyphosis and 12 patients had normal kyphosis.

结果：58例(42.03%)患者合并脊柱侧凸，男38例，女20例，男女患病率比例为1.18：1，其中≤10岁6例，11~20岁12例，21~30岁19例，31~40岁11例，41~50岁7例，51~60岁3例；平均冠状面Cobb角为26.8°±27.8°；胸弯36例，胸腰弯11例，腰弯2例，双弯6例，三弯3例；单弯中顶椎凸向右侧38例，凸向左侧11例；矢状面胸椎后凸平均为14.3°±13.2°，其中胸椎前凸5例，胸椎后凸不足40例，胸椎正常后凸12例，仅1例胸椎后凸45°；11例患者冠状面Cobb角＞40°，平均年龄15.9岁。

Although translator has turned from being a crystal ball by which the original culture can unrestrainedly penetrate to another crystal ball by which the target culture can freely traverse, the translator's personal embodiment, in the process of cognitive act, are still absent in translation studies. Translators are still subjects without body or simply disembodied subjects.

译者虽然由原语文化可以自由穿透的玻璃球变成了译语文化可以自由穿越的玻璃球，但译者认知过程中的个体体验在翻译研究中依然缺席，译者依然仅仅是一个没有躯体体验的主体。

Chillingly, he claimed our technology is 'not nearly as sophisticated' as theirs and "had they been hostile", he warned 'we would be been gone by now'.

令人毛骨悚然的，他声称我们的技术是'并不那么复杂，像他们一样，和"如果他们敌意"，他警告说，'我们将现在已经过去了。