查询词典 cartesian equation

From the ionization constant and electrical neutral principle of weak acid solution, we can draw out chemical balance equation of acid radical ion of acid salt, electric charge conservation equation and supplies conservation equation.

根据弱酸的电离常数和溶液的电中性原理等，可导出其酸式酸根离子的化学平衡式、电荷守恒式和物料守恒式，判断酸式酸根离子所引起的溶液酸碱性及其强弱，从而得出定量判据

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

The phase of optical wave can be recovered by the intensity transport equation under the paraxial approximation For the optical system with diffraction limit, it is difficult to get the boundary radical slope of phase and sample in the circular domain boundary when using the intensity transport equation to recover the phase, consequently, we reviewed an algorithm mentioned in the reference ［4］, namely, the equation, computation domain and boundary condition are changed, then the phase is reconstructed by the multigrid method and corrected at last Moreover, the experiment system is set to testify the algorithm, and the recovered phase from the intensity data detected by CCD is compared with the result from phase retrieval algorithm, it is found that the phase reconstruction error can reach 017 λ in the case of non-uniform intensity distribution, as a result, the method is suitable for the phase recovery with low wavefront sensing accuracy.

在傍轴近似条件下，可以利用光强传播方程对畸变波前进行相位恢复。对于衍射受限的光学系统，很难获得相位的边界径向斜率值作为边界条件，此外，要获得精确的圆域边界采样值也并非易事。为了克服上述困难，进一步研究了相位恢复改进方法，即改变了方程的表示形式、计算区域和边界条件，并用多重网格法进行求解获得重构相位，最后再将其修正。为了验证算法的精确性，搭建了实验系统对算法进行实验验证，将由CCD探测的光强分布进行计算得到的相位分布与相位恢复算法的结果进行比较，证明在光强分布非均匀的情况下，该方法恢复的相位均方根误差能够达到017 λ，可以适用于波前传感精度要求不是很高的相位恢复。标签自适应光学相位恢复相位修正光强传播方程 adaptive optics phase retrieval phase correction intensity transport equation

By making use of multi-points backward pressure of one dry gas well, this paper introduces how to confirm dynamic friction coefficient of downhole tubing at the exact moment through stable testing material, gives the productivity and the corresponding bottom hole pressure by using productivity equation, calculates wellhead pressure in combination with dynamic friction coefficient of tubing, establishes the correct wellhead outflow performance equation for this well, draws out wellhead outflow performance curve and discusses how wellhead outflow performance equation or wellhead outflow performance curve changes with the decrease of formation pressure or the change of wellhead outflow performance curve.

借助1口干气井的多点回压法试井资料，介绍了如何利用气井稳定试井资料，确定该气井此时此刻井下油管动态摩阻系数；利用产能方程给出产量和对应的井底压力，结合油管动态摩阻系数计算井口压力，建立该井准确的井口流出动态方程并编绘井口流出动态曲线；讨论了随着地层压力递减和井下油管动态摩阻系数变化规律，井口流出动态方程或井口流出动态曲线的变化规律。

An equation which is true only for certain value of a letter in it,or for certain sets of related values of two or more of its letters,is an equation of condition ,or simply an equation.

一个等式若仅仅对其中的一个字母的某些值成立，或者对其中两个或多个字母的若干组相关的值成立，则他是一个条件等式，或简称方程。

In this paper, we invert the condition equation into a complete nonlinear partial differential equation, and study some properties of the solution of this equation from a theoretical point.

本文把其条件方程转化为一个非线性偏微分方程，从理论角度探讨了一下此方程的解的一些性质。

Then the stationary joint probability density, the conditional reliability function, the mean first-passage time of the optimally controlled system are obtained from solving the reduced FPK equation, the backward Kolmogorov equation and the Pontryagin equation, respectively of fully averaged systems.

求解与之相应的Fokker-Planck-Kolmogorov方程得最优控制系统的联合概率密度，进而求得最优控制系统的平均幅值；求解与之相应的后向Kolmogorov方程得最优控制系统的条件可靠性函数，进而求得首次穿越时间的条件概率密度；求解与之相应的Pontryagin方程得最优控制系统的平均首次穿越时间。

Then the FPK equation governing the joint probability density of amplitude and phase, the backward Kolmogorov equation governing the conditional reliability function, and the Pontryagin equation governing the mean first passage time are established, respectively.

随机微分方程。在此基础上，建立联合概率密度满足的Fokker-Planck-Kolmogorov方程、条件可靠性函数满足的后向Kolmogorov方程以及平均首次穿越时间满足的Pontryagin方程，分别求解这些方程得到联合概率密度、条件可靠性函数以及平均首次穿越时间。

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＝。

Thirdly, we should start with momentum equation and equation of continuity. They offer theory basement through equation dispersion, interpolation of disheveled datas and analysis of turbulence coefficient.

再者，从动量方程和连续方程入手，通过方程的离散、散乱数据的插值、紊动粘性系数等的分析，为数学模型的建立提供理论基础。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。