微分

Through the limit difference method,the partial differential equation of the semiconductor device is transformed into a difference equation,and the corresponding boundary condition is discretized with high accuracy.

采用有限差分法把器件工作的偏微分方程转化为差分方程，并将相应的边界条件转化为精度较高的离散化形式。

A sufficient condition for the oscillation of bounded solutions of a kind of second order neutral differential difference equation s established.

建立了一类二阶中立型微分差分方程有界解振动的充分条件，且当变系数都是常数时，该条件也是必要的；同时，根据该方程的"极限"方程建立了它自身的一个有界振动准则。

The modeling of GM (1,1) model is to gain difference equation by dispersing albinism differential equation, then to estimate model parameters by the difference equation.

GM(1，1)模型的建模过程是由白化微分方程离散化得到差分方程，再由该差分方程估计模型参数。

Transpiration ; mathematical analysis ; heat transfer ; differential equation ; difference equation.

发汗；数学分析；热传导；微分方程；差分方程

The Fourier method and heuristic stability theory for the analysis of the computational stability criterion of the difference scheme of linear partial differential equation are also briefly introduced.

对分析线性偏微分方程差分格式计算稳定性判据的Fourier方法、启发性稳定性分析方法，也做了简要的介绍。

The relation between difference equation and differential equation is studied by analyzing the mechanism in building grey models, and a "bridge" is set up between difference equation and differential equation by sampling theorem and state transition matrix.

通过对灰色系统模型建模机理进行深入剖析，利用采样定理和状态转移矩阵在差分方程和微分方程之间架起一座桥梁，通过算例仿真实验证明了该算法的有效性。

Near the bifurcation point, the linear stability of difference differential equation which describes acoustooptic bistable systems is analyzed, the expression of resonance frequency and amplification multiple are given.

在分岔点附近，通过对描述布拉格型声光双稳系统的差分－微分方程进行线性稳定性分析，得到了系统对小信号放大时的共振频率，给出了放大倍数的表达式。

It is known theoretically that to the variational problem with weak constraints in cost functional J, its Euler equation can be discreted into difference format, by using matrix theory and difference method of partial differential equation we know that there exists optimal selection of weight factors in the cost functional under the condition of minimal variance between analysis field and ideal field.

从理论上可知，对于目标泛函J带有约束条件的变分问题，将其Euler方程离散成差分形式，利用矩阵理论和偏微分方程的差分方法，则目标泛函的权重因子，在分析场和理想场的最小方差意义下存在最优选取。

To discuss deeply, this article use indirect means to research by difference differential equation, that is: using the Liyapnof function to discuss the time delay stability of one-dimensionality force telepresence system in order to determine the time delay limits which could ensue the system work normal.

为了进一步深入讨论，本文还从差分微分方程入手，采用间接法进行进一步讨论，即：利用李亚普诺夫函数对一维力觉临场感系统的时延稳定性进行讨论，确定保障系统正常工作的时延界限。

Differential coefficient and difference simulation equation of gray model GM (1, 2), representing the relationship between 28d compressive strength and 4-32μ m particle content respectively is

颗粒粒级范围对强度的灰色系统关联度分析结果表明：对于普通硅酸盐水泥，4-8μm颗粒含量对水泥3d抗压强度的影响最大，8-16μm颗粒含量对水泥28d抗压强度的影响最大，对水泥90d抗压强度，则16-24μm颗粒的影响最大。28d抗压强度与4-32μm颗粒含量灰色模型GM（1，2）的微分方程和差分模拟式分别为

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。