查询词典 difference differential equation

The equation of ESCDAC is presented. Secondly, Based on this equation and the independent characteristic of observation valves, the ESR of the azimuth measurement error is presented by full - difference of the measurement equation which acts as the precision of ESCDAC.

然后以该方程为基础，根据该方程中各个观测量相互独立的特点，方位测量误差的均方根值可由测向方程的全微分求得，并将其作为电扫描恒差比幅测向的精度，由该精度公式可以看出，电扫描恒差比幅测向有很高的精度，并且在不同的角度上，其精度保持稳定。

In this paper, based on an optimum difference operator for spatial differential given by Holberg, an optimum difference method of modeling crosswell elastic wavefield is put forward, which adopts the staggered-grid technique and calculates the wavefield at different grid points. When the half length of optimum difference operator is taken as four to six points, the required number of grid points per wavelength equals to three, crosshole elastic wavefield numerical modeling can attain satisfied accuracy.

本文以Holberg提出的一种空间微分的最佳差分算子为基础，采用交错网格技术，提出了一种模拟井间弹性波场的最佳差分法，该方法能在大空间网格点上得到精确的波场值，当最佳差分算子的半长度取4～6个点，每个波长只采3个样点时，井间弹性波场的模拟就可以得到满意的精度，其计算速度比常规有限差分法至少快一个数量级。

CT perfusion images can visually show different traits of Hemodynamics of hepatic Benign and Malign pathology; No matter what background, various parameters of hepatic tissue around malign lesions had significant difference with far-end liver tissue, while various parameters of hepatic tissue around benign lesions had no significant difference with far-end liver tissue; Allopatric efficiency of hepatic Malign pathology distinctly went up with hepatocirrhosis background;Various parameters of hepatic Benign and Malign pathology had no significant difference and differential significance were no significant.

灌注参数图像能直观显示肝脏良、恶性占位性病变血流动力学的不同特点；无论在何种背景下，恶性病变灶周组织与远端肝组织各同种参数间有显著差异，而良性病变灶周组织与远端肝组织各同种参数间无显著差异，以上特点可以鉴别肝脏占位性病变的良、恶性；肝硬化背景下，恶性病变的发生率明显增高；正常肝组织背景下，良、恶性占位病变组织灌注参数间无显著差异，鉴别诊断意义不大。

The optimal control law obtained consists of linear analytic functions and a compensation term which is a series sum of the adjoint vectors. The analytic functions can be found by solving a Riccati matrix difference equation and a matrix difference equation. The compensation term can be obtained by a recursion formula that solves adjoint vector equations.

得到的最优输出跟踪控制律由状态向量的线性解析函数和伴随向量级数形式的补偿项组成，其解析函数由一次性求解Riccati矩阵差分方程和矩阵差分方程得到，补偿项由求解伴随向量差分方程的递推公式得到。

It takesthe weighted average of the L2 norm of the difference of the observation and thesolution of the system and the L2 norm of the difference of conormal derivativeat the different sides of the interface for every subdomain as cost functional andthe smooth coefficients of the subproblem and the value of solution of the originalproblem at interface as identification parameters;Using the property of continu-ous functional defined on compact set,the existence of the optimal solution of theidentification problem is proved;The necessary conditions of optimality charac-terized by the system equation,the adjoit equation and the variational inequalitysimultaneously are given by introducing the conception ofdifferential andadjoit variable;An algorithm is devised and its flow graph is given.

其次，针对分片光滑动力系统的特征，结合正演过程的区域分解算法，建立了分片光滑系统的分解区域参数辨识模型，该模型以子区域上解的实测值与计算值之差的L2范数和界面两侧的通量差的L2范数的加权平均作目标泛函，各子问题的光滑系数及界面上真解的值为待辨识参量；利用紧致集上连续泛函的性质，证明了子区域上参数辨识问题最优辨识参量的存在性；引入微分的概念，借助伴随变量，给出了由系统方程，伴随方程和变分不等式共同表征的最优性必要条件；根据此必要条件设计了算法，给出了算法的程序框图。

This model used the finite—difference approximation to the advection— dispersion equation. The spatial derivatives in the flow equation are approximated by central difference written about grid—block boundaries and time derivatives are approximated by a fully implicit backward scheme.

水流方程的空间导数采用中心差分格式离散，时间导数采用隐式差分格式离散，建立了土壤水分和污染物在各种饱和度的条件下迁移转化方程耦合求解的二维数值计算模型。

The input - output relationship of any linear time-invariant discrete system can be described by a difference equation The complete solution of a linear difference equation consists of two parts: the free component and the forced component.

任何一个线性时不变离散系统的输入输出关系都可用线性差分方程式来描写。差分方程式的解答包括两部分：即自由分量和强制分量。

In this paper, the author is concerned with the problems that are to be solved in the field of Partial Difference Equations such as the following: the existence of oscillatory solutions of some partial difference equation, the asymptotic behavior of positive solutions of the same equation.

本文旨在研究当前偏差分方程领域中尚待解决的有关振动解的存在性及正解的渐近存在性等问题。

In this paper difference equation of motion fr om one point to another point on the earth is derived from the geodesic equation on the earth and spherical trigonometry formulas. Some difference track formul as of a maneuvering object are also given.

以大地椭球三角形模型为基础，利用地球表面二点间最短路径的大地线方程和球面三角形的有关公式，建立了由地球表面一点运动到另一点的差分运动方程，同时也给出了在进行航向机动时的差分运动轨迹。

By considering higher orderapproximation to interaural phase difference,a moregeneral localization equation(which is applicable to f＜1.4kHz)is derived,and the localization equation forstereo sound image with interchannel phase difference isalso given.

并且提出了重发通路间存在相位差时的立体声声像定位公式。

There had been a moment during the breakfast meeting, though, after the backslapping and the small talk and when all of us were seated, with Vice President Cheney eating his eggs Benedict impassively and Karl Rove at the far end of the table discreetly checking his BlackBerry, that I witnessed a different side of the man.

那次早餐会期间，在表示过关心和寒暄以后，我们所有人坐了下来，我注意观察了一下，副总统切尼面无表情地吃着班尼迪克蛋（Eggs benedict，源自美国，以英式松饼、火腿、水煮蛋以及荷兰酱组合而成），卡尔。罗夫在餐桌的远端谨慎地经常查看他的黑莓手机，我目睹了他所不为人知的一面。

Talk Undelete failed; someone else may have undeleted the page first.

Talk 无法删除选定的页面或图像（它可能已经被其他人删除了）。