导数

From equations eliminated some unknown function and its derivative, are contained only one unknown function with constant coefficient of linear differential equations.

从方程组中消去一些未知函数及其各阶导数，得到只含有一个未知函数的高阶常系数线性微分方程 9。

Firstly, the approach formulates a cost functional to turn the inverse problem into a constrained minimization problem according to least squares criterion, then the resulting constrained minimization problem is transformed into an unconstrained minimization problem by using a penalty function technique, and then the closed Fr chet derivatives of the Lagrange function with respect to the properties are derived based on the calculus of variations, finally, one can solve the resulting problem by using any gradient-based algorithm and the finite-difference time-domain method.

该方法首先以最小二乘准则构造目标函数，将逆问题表示为约束最小化问题；接着应用罚函数法转化为无约束最小化问题；然后基于变分计算导出闭式的拉格朗日函数关于特征参数的Fr chet导数；最后借助梯度算法和时域有限差分法迭代反演德拜模型参数。

Through a test, questionnaire survey and interviews, this paper intends to investigate the images of the freshmen with different specialities about the concepts of limit, continuity andderivative of a function at a point x_0 and the relationship among them.

函数在点x_0处的极限、连续和导数三者概念，本文通过问卷调查和访谈，对不同专业的大学一年级本科生的概念表象和三者关系的理解水平进行了研究，而且对三个专业进行显著性差异比较。

Continuity on first derivative of wave function is discussed by means of several instances of finite and infinite transition s of potential function and hereby continuity conditions is pinpointed.

结合势函数有限跃变和无限跃变的几种实例，讨论波函数一阶导数在势函数跃变处的连续性问题，从而进一步明确连续性条件。

The study shows the BP neural network model of hydro-turbine for s pecial discharge and special torque can be used to describe its nonlinear charac teristic and ensure the continuity of derivative function of special discharge. The convergence for hammer calculating is improved.

水轮机单位流量和单位力矩特性的BP神经网络模型能真实地表达水轮机的非线性特性，且解决了插值法的导数不连续问题，从而改善了水击计算的收敛性，为用于工程计算和科学分析的水轮机特性表达开辟了新的途径。

The study shows the neural network model of hydro turbine can describe its nonlinear characteristic really and ensures the continuity of its derivative function, so improved the convergence for hammer calculating and is a better description of hydro turbine hill chart for science research and engineering design.

利用所述方法建立的水轮机特性神经网络模型能真实地表达水轮机的特性，并且解决了插值法的导数不连续问题，从而确保了水击计算的收敛性，为用于工程计算和科学分析的水轮机特性表达开辟了新的途径。并利用所建立的数学模型，开发了基于MATLAB的可视化软件仿真平台。

Based on the modal superposition method and the exact solution of beam nature vibration, the motion equations of the simply supported and continuo...

基于模态叠加法和梁固有振动的精确解，建立了移动荷载作用下简支梁和连续梁的运动方程；利用样条最小二乘法逼近桥梁应变响应，由样条数值微分求得响应导数；再通过Tikhonov正则化方法结合奇异值分解技术得到了荷载识别的正则解。

This approach was to replace the derivative operator in the continuous time model by an approximation and estimation of the physical parameters of structures by the least-squares method.

讨论了导数近似值的选择方法，并分析了算法的收敛性。

Firstly, we prove that if we select nodes properly, and let the distance between these nodes sufficiently small, cubic polynomial spline can approximate a continuously differentiable function, which with continuous derivatives of second order and discontinuity of the first kind in the derivatives of fourth order, to any desirable accuracy. This result lays a theoretical foundation for representing trajectories by splines and double orthogonal basis.

一是证明了适当选取节点并使节点距充分小时，三次多项式样条可以逼近具有二次连续导数的分段四次连续可微函数到足够的精度，这一结论为用样条和双正交基表示弹道打下了理论基础。

In the third chapter, we study the approximation and weighted approximation for a kind of generalized Baskakov operators of two-variable. Using different weight functions, we discuss the convergence on weighted space of polynomials and rate of convergence with Jacobi weight for this kind of two-dimensional product-type operators, which extends the results of one-dimensional operators.

第三章研究一类二元广义Baskakov算子的逼近及其加权逼近，主要针对于不同的权函数讨论了这类乘积型的二元算子及其导数在多项式权空间上的收敛性和加Jacobi权的收敛阶，把一元的结果推广到多元的情形。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。