特征方程

The new method is a combination of characteristic approximation to handle the convection part, to ensure the high stability of the method in approximating the sharp fronts and reduce the numerical diffusion, a smaller time truncation is gained at the same time, and a mixed finite elementspatial approximation to deal with the diffusion part, the sealer unknown and the adjoint vector function are approximated optimally and simultaneously.

此方法即为对方程的对流项沿流体流动的方向即特征方向进行离散，从而保证格式在流动锋线前沿逼近的高稳定性，消除了数值弥散现象，并得到了较小的时间截断误差；另一方面，对方程的扩散项采用混合元离散，可同时高精度逼近未知函数及其伴随向量函数，理论分析表明，此方法是稳定的，具有最优的L~2逼近精度。

The characteristic approximation is used to handle the convection part along the direc-tion of fluid namely characteristic direction to ensure the high stability of the method in approximating the sharp fronts and reduce the numerical diffusion; The mixed finite element spatial approximation is employed to deal with diffusion part and approximate the scalar unknown and the adjoint vector function optimally and simultaneously; In order to preserve the integral conservation of the method, we introduce the modified characteristic method.

该方法对方程的对流部分沿流体流动的方向即特征方向离散以保证格式在流动的锋线前沿逼近的高稳定性，消除数值弥散现象；对方程的扩散部分采用最低次混合有限元方法离散、同时以高精度逼近未知函数及未知函数的梯度；为保证方法的整体守恒性，在格式中引入修正项。

Based on the involute's basic principles and theoretical formulas, input the involute's formulas of cartesian coordinates into the equation editor, accordingly create the precise involute of gear's contour. Based on the formula of helical gear's parameters, accurately create a curve of tooth profile. Create the chraceristics of helical gear by ordering of swept blend and array.

依据渐开线生成的基本原理和理论公式，在方程编辑器中输入渐开线的笛卡尔坐标方程，从而生成精确的齿轮轮廓渐开线；根据角变位斜齿轮各参数的计算公式，精确创建了齿廓曲线；利用扫描混合和阵列命令创建斜齿轮的轮齿特征。

In particular,the phase function of the disturbance wave system is solved by uting the characteristic theory of partial differential equation and an expan sion of Orr-sommerfeld eigenvalue problem,insteade of using the disturbance model which was given previously.

其特点是。应用偏微分方程特征理论以及O－S方程特征值的展开，求解扰动波的相函数而不是预先给定扰动波的波动形式。

Based on the curve estimate of sap flow characteristic of Quercus acutissima using manifold curve model, the simulation curvilinear equation of environmental factors to sap flow were founded, but the availability of these equations differed each other.

基于对多种曲线模型对麻栎液流特征进行曲线估计，分别建立了各环境因子的模拟曲线方程，方程的有效性存在差异。

It takesthe weighted average of the L2 norm of the difference of the observation and thesolution of the system and the L2 norm of the difference of conormal derivativeat the different sides of the interface for every subdomain as cost functional andthe smooth coefficients of the subproblem and the value of solution of the originalproblem at interface as identification parameters;Using the property of continu-ous functional defined on compact set,the existence of the optimal solution of theidentification problem is proved;The necessary conditions of optimality charac-terized by the system equation,the adjoit equation and the variational inequalitysimultaneously are given by introducing the conception ofdifferential andadjoit variable;An algorithm is devised and its flow graph is given.

其次，针对分片光滑动力系统的特征，结合正演过程的区域分解算法，建立了分片光滑系统的分解区域参数辨识模型，该模型以子区域上解的实测值与计算值之差的L2范数和界面两侧的通量差的L2范数的加权平均作目标泛函，各子问题的光滑系数及界面上真解的值为待辨识参量；利用紧致集上连续泛函的性质，证明了子区域上参数辨识问题最优辨识参量的存在性；引入微分的概念，借助伴随变量，给出了由系统方程，伴随方程和变分不等式共同表征的最优性必要条件；根据此必要条件设计了算法，给出了算法的程序框图。

On the basis of analyzing the lilnitations of the conventional flow equation for rotameter , ac-cording to principle of mechanical energy conservation and transform for real fluid, a new generalflow equation Q=for rotameter has been developed.This equation includes the rota-form factor β to reflect the influence of rota-form on flowmeasurement.

在分析转子流量计习用流量方程局限性的基础上，根据实际流体机械能守恒与转换原理，定义了反映转子形状特征对流量测定影响的转子几何形状因子β；经过推导，最终获得了转子流量计一种新的普遍流量方程Q＝。

By means of the eigenvalue theory of partial differential equation, the crosswind and vertical sub-Green functions corresponding to the boundary types are derived.

引用Green函数的概念，提出了公路机动车多源扩散方程的求解思路，利用微分方程的特征理论，求得了Green函数的横风和垂直向分量。

We build the model for the enveloping worm helix parametric equation and then analyze its relations with the enveloping worm helix tooth surface equation,thus establishing the characteristic model of the involute helicoid enveloping worm′s generative gears.

渐开面环面蜗杆的三维构建属复杂曲面造型，文章在环面蜗杆螺旋线参数方程建模的基础上，分析讨论了其与渐开面环面蜗杆螺旋齿面方程的对应关系，建立了渐开面包络环面蜗杆产型齿的特征模型。

By designing three hierarchical factors of "corporate governance characteristics","medium agent characteristics" and "corporate basic characteristics", we applied a more integrated and systematic approach to study the influencing factors. Besides, our hierarchical regression analysis has more explanative effects.

在影响因素的研究上，设计&公司治理结构特征&、&中介机构特征&、&公司基本特征&三个层面因素，并通过具体指标予以计量，较以往内部控制信息披露研究方面单个指标的设计，更为综合考虑和系统分析，并运用层次回归方法深入分析因果关系，相对一般信息披露研究中的普通线性回归对各个因素的作用效果分析更为清晰，回归方程具有一定的解释能力。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失