查询词典 difference equation

In this article, with pointing out that the result of the current calculation model is deficient in the similarity, it has deduced the numerical regulation of the variation of the elements including q ,γ andτ in the steam-water distribution matrix equation when the terminal temperature difference exits in the heater via the power balance equation, and combining with the power equation and boiler absorbed heat equation, the precise calculation model for the impact of heater terminal temperature difference on heat economy of unit is then derived.

指出现有计算模型结果具有近似性的不足，本文通过加热器能量平衡方程推导出加热器有端差时汽水分布方程中q 、γ和τ元素数值的变化规律，然后结合功率方程和吸热量方程得到加热器端差对机组热经济性影响的精确计算模型。

In this paper, a high order accuracy difference method is presented for solving unsteady convection diffusion equation by using Implicit Perturbation Finite Difference scheme. Firstly, we use the steady convection diffusion equation, the constant coefficients of this equation are expanded to power series of grid-spacings, then the high-order Perturbation Finite Difference scheme is obtained by determining the coefficients of the power series. Put this scheme on unsteady convection diffusion equations and modified it, the IPFD scheme is constructed.

本文利用摄动差分思想，对定常对流扩散方程中的空间微商系数进行摄动展开，展开幂级数系数通过消去摄动格式修正微分方程的截断误差项求出，由此获得方程的隐式摄动差分格式，将此方法应用于非定常对流扩散方程，并加以修正，得到该方程的修正隐式摄动差分格式。

Inspired by Chans double series representation formula of_∞~(10), the author constructs a new difference equation on quintuple products, which leads to clarification on the four symmetric differences that are equivalent in pairs.

受Chan得到的_∞~(10)的二重级数表示公式的启发，作者构造一个新的关于五重积的差分公式，并澄清迄今为止所出现的四个对称差恒等式之间成对等价的关系。

Key words: applied mathematics; forth-order difference equation; discrete variational principles; periodic solution

关键 词：应用数学；四阶差分方程；临界点理论；周期解

With the help of the theory of difference equation and some subtle analysis, sufficient conditions which ensure the permanence of the system are obtained. By constructing a suitable Lyapunov functional, sufficient conditions which ensure the global attractivity of the system are obtained.

首先利用差分方程的有关理论以及技巧性的计算，得到保证该系统永久持续生存的充分性条件；其后通过构造适当的差分Lyapunov泛函，得到保证该系统全局吸引的充分性条件。

Increasing the dimensions and burying depth of the grounding electrode, as well as the ground conductivity can effectively decrease the grounding impedance. In terms of the FDTD algorithm, an unsplit formulation of the Berenger''s PML and MPML and the modified difference equation near the sharp metal edge in FDTD grid are presented.

在FDTD算法方面，提出了Berenger PML及MPML场分量非分裂形式的公式；对金属薄板边缘场差分方程进行了修正，取得与实测数据一致的计算结果。

The accuracy of receiver clock parameter got from point positioning is not high enough to be introduced into the double difference equation. In order to get the accurate receiver clock error, high quality cymometer will be needed, while this is not applicable for the real work.

由于用伪距求得的接收机钟差不能满足精度要求，要想精确求得接收机钟差，需要高精度的频率计，这在实际应用中难以做到，而求解参考卫星站间单差模糊度的方法则是可行的。

Enterprise management ; market share model ; difference equation theory ; freight traffic volume

企业管理；市场占有率模型；差分方程理论；货运量

In the second part, we make the study of the application of Z-transformation when we solve linear difference equation bearing constant coefficient and transmission function in pulsing system.

第2部分：&Z变换的应用&，主要通过上1章研究的Z－变换的逆变换和10个性质定理，研究了Z－变换在求解具有常系数的线性差分方程和脉冲系统的传递函数方面的应用。

Based on the discrete-time difference equation of the plant,an explicit solution of Diophantine matrix polynomial equations in multivariable generalized predictive control is derived without appealing to Diophantine matrix polynomial equations recursions or iterations,which makes the applications of generalized predictive control much more convenient.

直接利用被控对象的离散差分方程推导出多变量广义预测控制中Diophantine矩阵多项式方程的显式解，从而避免了其递推求解或迭代求解，使广义预测控制的应用更加方便。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。