待定

Newtonian fluid; helical flow; eccentric annulus; pressure gradient; undetermined coefficient method

Newton 流体；螺旋流动；偏心环空；压力梯度；待定系数法

For overcome nonlinear terms of any degree in the equation, we made a proper transformation according to the structure of the equation at first, make the equations into ordinary differential equation. Then solve the ordinary differential equation exactly, by auxiliary functions method and undetermined the coefficient method and algebraic computer system Mathematica.

为了克服方程中非线性项的任意次幂，我们采用的方法是首先根据方程的特点，做适当的变换，使原问题转化为常微分方程的问题，其次对该常微分方程再进行各类变换，如辅助函数法以及待定系数法……。

The "divide and conquer" strategy is used to improve the key steps of the undetermined coefficient algorithm for constructing polynomial conservation laws of nonlinear DDEs, so the calculation complexity problem caused by the dramatic increase of redundancy is solved. Furthermore, Wu\'s elimination method is applied to solve the obtained nonlinear algebraic equations thus to get a more efficient algebraic algorithm.

本文从微分方程的标度变换出发，利用"分治"策略改进了构造非线性DDE守恒律待定系数算法中的关键步骤，有效解决了因冗余项急剧增加引起的中间计算过程膨胀问题，并将吴消元法应用到非线性代数方程组的求解上，从而给出了一个更高效的代数算法。

The polynomial function bases are used to form the approximately matching function. Moreover, the discrete values of grey image is transformed to polinomial function that are exact fit at the considered pixel locations. As a result, The mathematical operations performed such as derivation, integration, and gradient evaluation also give out the polynomial functions, therefore, the system of undetermined coefficient equations is derived to be a system of linear algebraic equations.

我们把立体匹配过程看作泛函的极小化过程，因此选用变分问题近似解法的Ritz法构造数值算法，以多项式函数为基构作匹配函数的近似解，进而又利用多项式过样值点的拟合将离散的灰度图象变换为多项式函数，因此计算中所需的求导，积分，及梯度运算的结果仍然是多项式函数，最终将待定系数方程组化为线性代数方程组。

Based on Wu's elimination method and "divide-and-conquer" strategy, the undetermined coefficient method for constructing polynomial conservation laws of nonlinear differential-difference equations was improved. Furthermore, a Maple package CLawDDEs was developed to automatically derive conserved densities and associated fluxes of polynomial differential-difference equations.

基于吴消元法和"分治"策略，改进了基于标度不变性构造非线性微分差分方程多项式形式守恒律的待定系数算法，并在计算机代数系统Maple上实现了改进后的算法，其中的软件包CLawDDEs可自动推导出微分差分方程的守恒密度及连带流。

According to the characteristics of peaked soliton solution, the undetermined coefficient method for solving nonlinear wave equations for their peaked soliton solutions is submitted and by means of the method several kinds of peaked soliton solutions are obtained for five nonlinear wave equations: the Camassa-Holm, fifth -order KdV-like, generalized Ostrovsky, combined KdV-mKdV and Klein-Gordon equations.

刘煜 河南电力试验研究院，郑州 450052根据尖峰孤子解的特点，提出了一种待定系数法求非线性波方程尖峰孤子解的思路和方法，并利用该方法求解了5个非线性波方程，即CH（Camassa-Holm方程、五阶KdV-like 方程、广义Ostrovsky方程、组合KdV-mKdV方程和Klein-Gordon方程，比较简便地得到了这些方程的尖峰孤子解。

The model/L=f(a(1-ε)/(ε~3)u~2 coulddepict the overland flow in the litters, there f" was a undetermined coefficient, when the flowvelocity was very low, the Ergun equation f"=(4.17)/+0.29 could depict the overland flow.

坡面流在枯落物中流动的数学模型，可用下述模型描述hf/L=f"a(1-ε_ε3u2，其中包括一个未知的待定系数f"，在流速较低时，可用欧根方程描述：f=4.17/Re+0.29。

According to this method, all the undetermined parameters can be determined without fitting them to experimental data.

用这种模型计算旋流器的迁移率不需用实验数据拟合待定参数，避免了实验误差的影响。

At higher pressures, six-body effects become significant, and the inclusion of its contribution can extend the theoretical prediction from 60 to 180 GPa, where the empirical Vinet EOS give a lower prediction by 6-14%.

结合双原子势能函数，证明了单原子对体系总势能贡献分量的计算公式E=1/2[β~2U_2+(1-β~2)V_n]，对于高压氦体系，其中待定参数β的取值约0.5。

In this paper, the authors consider point-feature cartographic label placement from a combinatorial optimization point of view.

地图注记是为待定位注记求取注记位置的过程，它是自动地图制图中的一个重要的难题，其中点状注记问题可以看作是一个组合优化问题。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。