查询词典 difference equation

Instead of Hildebrand equation to treat the results of experiment,the equation of two-dimensional solubility parameters has been used to gain the nonpolar part of solubil...

本文讨论了方法的准确性和合理性，并用二元溶解度参数公式代替Hildebrand公式对实验结果进行处理，得到了聚醚溶解度参数的非极性部分，它们分别为6.44、7.15和7.53（cal／cm3）。

Then, on the basis of above achieved constituent binary results, thermodynamic properties of 10 ternary liquid alioys (Cd-Bi-Pb, Cd-Pb-Sb, Cd-Pb-Sn, Mg-In-Cd, Zn-In- Cd, Cd-Bi-Sn, In-Bi-Pb, Sn-AgPb,Zn-In.Pb, Al-Cu-Zn), 3 quaternary ones (Cd-Bi-Pb-Sn, Zn-Sn-Cd-Bi, Zn-Sn-Cd-Pb) and 1 quinary. one (Zn-Sn-Pb-Cd-Bi) are predicted. For most of investigated multicomponent systems, the calculated activities are in good with the experimental ones, and in particular for multicompoment immiscible ones, the predicted results are satisfactory and exciting. At the same time, the comparison result between the three equations shows that Wilson equation and T-K-Wilson one are more stable than NRTL one, that maybe is because NRTL equation contains a third parameter, and so ,to some degree, Wilson model and T-K-Wilson model are superior to NRTL model. And also the comparison between local composition models and other models such as Pelton- Flengas?method, Krupkowski formalism, mass action concentration model and Hoch- Arpshofen model shows that local composition models are more convenient and credible.

在此基础之上应用局部组成型模型对10个三元液态合金（包括Cd-Bi-Pb、Cd-Pb-Sb、Cd-Pb-Sn、Mg-In-Cd、Zn-In-Cd、Cd-Bi-Sn、In-Bi-Pb、Sn-Ag-Pb、Zn-In-Pb、Al-Cu-Zn），3个四元液态合金（包括Cd-Bi-Pb-Sn、Zn-Sn-Cd-Bi、Zn-Sn-Cd-Pb）和1个五元液态合金（Zn-Sn-Pb-Cd-Bi）的活度进行了预测，预测效果良好，尤其对Zn-In-Pb系和Zn-Sn-Cd-Pb等多元液-液共存体系热力学性质的预测也取得了令人满意的结果；同时对三个方程的比较分析表明：Wilson方程和T-K-Wilson方程在多元系热力学性质的预测中表现稳定，而NRTL方程由于引入了物理意义不清楚的第三参数，使得其具有不确定性和不稳定性的特点，因此Wilson方程和T-K-Wilson方程较NRTL方程更为优越；此外对局部组成型模型与其它模型（如Pelton-Flengas方程、Krupkowski方程、作用浓度模型和Hoch-Arpshofen模型）的比较表明：局部组成型模型同样是优秀的，甚至在某些方面更为简便和可靠。

According to the boundary conditions,Laplace equation of SEW before the media changing abruptly and the homogeneous wave equation after the media changing abruptly were constructed.

结合相应的边界条件，建立了球面电磁波入射到时变媒质时的Laplace方程和时变媒质突变后的齐次波动方程。

According to the boundary conditions, inhomogeneous wave equation of point source before the media changing abruptly and the homogeneous wave equation after the media changing abruptly were constructed.

根据相应的边界条件，建立了球空间时变媒质点源激励的非齐次波动方程及媒质突变后的齐次波动方程。

One kind is using the particular solution of the indefinite equation, which can be obtained by the property of the prime number , and the foundation system of solution of its corresponding homogeneous equation ,obtains its solution formula. Another kind is under the foundation of the matrix primary line transformation, and with the aid of some knowledge of numeral theory, obtains its solution formula.

一种是利用该不定方程的一个特解和其相对应的齐次方程的一个基础解系，得出该不定方程的求解公式，而这个特解可以由素数性质得到；另一种是在矩阵的初等行变换基础上，借助一些数论知识，得出该不定方程的求解公式。

By means of Taylor's formulas and the extended homogeneous capacity method, the nonlinear equation is transferred into a linear homogeneous equation within an integral segment, which can be solved conveniently by the high precision integration method.

首先，借助Taylor级数展开，在一个积分步长内将非线性方程转化为线性非齐次方程，然后利用齐次扩容方法，进一步将其化为线性齐次方程组，便于用精细积分算法求解。

In §2, four met0hods for solving the integrable second order homogeneous linear ordinary differential equation with variable coefficientsy +py'+Qy=0 are given. Thus, the equation can be solved by means of elementary integrals and algebra.

给出了二阶变系数线性方程y＂＋py＇＋Qy＝0在可积的条件下的几种不同的求解方程，从而说明了这种可积的二阶方程不仅能用初等积分法求解而且也可以把它代数化，并使其通解公式化。

Through the Hooke＇s law and the compatibility equation, the governing equation of the plane problem was derived.

由胡克定律和形变协调方程得到平面问题的控制方程。

Based on the hydrokinetics study of jigging process, the free vibration equations of ideal fluid and actual flow vibration equations have been established. These equations are the theoretical foundation to set the operation parameters and air pressure of the jig. The similar criteria and their related equation of model jig have been deducted by actual flow vibration equation. These similar criteria can be used for parameter transformation between model jig and industrial jig. One set of single cell model jig with measuring system has been constructed in laboratory.

本文通过对跳汰过程的流体动力学研究，建立了跳汰机中理想流体的自由振动方程和实际水流的振动方程，为跳汰机工作制度及风源风压的确定提供了理论依据；利用跳汰机中实际水流的振动方程推导出了跳汰机模型试验的相似准数，建立了模化准则关系式，为工业跳汰机与实验室跳汰机之间的参数转换提供了理论依据；并设计建造了一套实验室单槽模型跳汰机及其实验检测系统，为深入开展跳汰理论的研究创造了条件。

The purpose of the paper is to investigate the convergence of the mixed finite element method for the initial-boundary value problem for the Hyperbolic type integro-differential equation and Hyperbolic type equation.

本文讨论了双曲型和双曲型积分微分方程的标准混合有限元和H~1-Galerkin混合有限元方法的L~2模和H~1模的误差估计。

Chinese traditional virtue is humility and wariness,the compliment and praise to the others should be declination

中国人的传统美德是谦虚谨慎，对别人的恭维和夸奖应是推辞。如

We bought this house on the never-never.

我们以分期付款的方式买下这座房子。