查询词典 difference

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。

A new scheme for approximating the solution of 2D Maxwell's equations-the high order symplectic scheme is proposed to overcome the shortcoming of the conventional finite difference time domain. The scheme is obtained by discretizing the Maxwell's equations in time domain based on symplectic scheme with high order, and then evaluating the equation in spatial domain with second or fourth order finite difference approximation.

为克服标准时域有限差分方法的缺陷，引入一种新的数值计算方法－高阶辛算法求解Maxwell方程，即在时间上用高阶辛差分格式离散，空间分别采用二阶及四阶精度的差分格式离散。

College of Guandong Business, Guanzhou 510320, China）Abstract: Since large-scale vertical quench furnace is voluminous, whose working condition is a typically complex process with distributed parameter, nonlinear, multi-inputs/multi-outputs, close coupled variables, etc, dynamically decoupling control algorithm of temperature distributed parameter system in the furnace was presented, by which the whole system was decoupled to several subsystems and the implementation of controller was simplified. With finite difference approximation, the space and time step size was solved to ensure the convergency of finite difference approximation. After decoupling, the subsystems were controlled with self-learning PID control algorithm. The results show that the temperature control precision and homogeneity are improved; the overshoot and process in temperature rising period are reduced simultaneity.

摘 要：针对大型立式淬火炉体积庞大，工况复杂，炉内温度分布呈本征非均匀性，具有多输入/多输出、非线性、强耦合等特性，难以实现炉内温度高精度高均匀性控制目标等问题，提出一种温度分布参数系统动态解耦控制算法，其原理是：采用有限维逼近方法将对象解耦为多个独立的子系统，简化控制器的实现过程；通过分析有限维逼近方法的收敛性，获得保证收敛性的空间和时间步长应满足的条件；解耦后的子系统采用自学习PID控制算法，实现炉内温度高精度和高均匀性控制以及升温过程的快速性和小超调。

There are many ways to analysis and computation of Mikthw's two rotations equation,finite difference method is the most one while using the finite difference method,a flood of data need be collected and computed.

而在目前高性能计算机系统中，最广泛使用的并行环境是MPI(Message Pass-ing Interface)，它已成为一种并行程序的标准。

Maxwell's equations are replaced by a set of finite difference equation. If we solve it in time domain, we can get Finite Difference Time domain method.

从麦克斯韦方程出发建立地质雷达的数学模型，麦克斯韦方程可以转化成有限差分方程组，若在时域中对其求解就是时域有限差分方法。

The main contents of this course include: the construction, convergence, compatibility and stability of finite difference scheme of elliptic equation, parabolic equation and hyperbolic equation, the construction method and computation format of finite difference scheme of a system of partial differential equations.

本课程主要内容有：椭圆型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、抛物型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、双曲型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、偏微分方程组的有限差分格式的构造方法及有关的计算格式。

However, the difference between Hongge and Xinjie is also apparent, perhaps reflecting the source difference in the mantle. Relative to the Hongge intrusion the Xinjie intrusion is more depleted in Nd isotope ratio and enriched in REE and LILE. The Xinjie intrusion plots in the first quadrant in Sr-Nd diagram, which shows the Sr isotope-enriched and Nd isotope-depleted slightly feature. This indicates that the source of the Xinjie intrusion may had the mantle wedge signature.

但红格、新街岩体的源区又有所不同，新街岩体较红格岩体Nd同位素更亏损，稀土和大离子亲石元素更富集；新街岩体在Sr-Nd相关图上，位于第一象限，显示Sr同位素富集，Nd同位素略亏损特征，指示了新街岩体的源区可能有残留地幔楔的成分。

It pretty much has to, as the operating current for both stages is the same, the series resistance is only trivially different compared to the forward biased input impedance of a triode grid (10's of K's for the typical duotriode input), and the voltage divider ratio difference between 100/10K and 470/100K is 0.990099 versus 0.995322, an inaudible amplitude difference.

相当有作为的经营现为两个阶段是相同的，一系列的阻力，只是没有太大的不同，相对于前进偏颇输入阻抗三极管一格(10年代K的对典型duotriode投入)，该分压器比例相差100/10k和470/100k是0.9900990.995322versus，inaudible幅度差。

This paper is based on the necessity analysis of regional difference and takes the example of Shenzhen, it raises the process and the method of regional difference and brings forward ultimately the using suggestions on traffic impact analysis.

本文在进行区域差别必要性分析的基础上，以深圳为例，提出进行区域差别分析的步骤及方法，并最终提出在交通影响分析中的应用建议。

When the forward slip difference is large,the influence of velocity difference is small and workpiece is easily bent.

经试验结果分析，弯曲是轧件上、下表面前滑差和速差综合作用的结果。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。