查询词典 diffusion equation

This one-way wave equation fits eikonal equation and transport equation corresponding to full acoustic wave equation in travel-time and first order amplitude. According to the perturbation theory often used in inverse solution, we split the velocity field into intraformational constant velocity background and variable velocity disturbance. Then we calculate time-shift quantity of migration and amplitude correction coefficients for wavefield depth continuation in total uniform formation and each formation.

基于反问题求解中常用的摄动理论，把速度场分裂为层内常速背景和变速扰动，求得整个均匀层波场深度延拓的偏移时移量及振幅校正系数、各层的偏移时移量及振幅校正系数，从而得到一个基于傅里叶有限差分法的双域保幅叠前深度偏移算子方程。

Elovich equation,zero order equation ,first order equation and parabolic equation was used to describe the nonexchangeabe k releasing process.Then the best model was selected to describe nonexchangeable k release and its velocity.

利用Elovich方程、零级方程、一级方程和抛物线扩散方程对土壤的累积释放量进行模拟，研究探讨了描述土壤非交换性钾释放及其速率较为理想的动力学模型。

The relationship equation is formally comporting with Huggins equation, Batchelor equation and Simha equation, and can explain the intrinsic property of latex systems.

该关系方程式与Huggins方程式、Batchelor方程式、Simha方程式形式上一致，但更能说明乳胶粒子体系的内在属性。

In this thesis, different types of stability equations, including Orr-Sommerfeld Equation and Parabolized Stability Equation based on the"slow change"hypothesis and the local method equation which is computed in local range, are derived from Navier-Stokes equation with"small disturbance"hypothesis.

摘要本文从Navier-Stokes方程出发，导出不同形式的流动稳定性方程，包括采用小扰动理论得到的Orr-Sommerfeld方程、基于流向慢变特性而得到的抛物化稳定性方程以及在一小范围内计算的局部法方程。

In this thesis, different types of stability equations, including Orr-Sommerfeld Equation and Parabolized Stability Equation based on the"slow change"hypothesis and the local method equation which is computed in local range, are derived from Navier-Stokes equation with"small disturbance"hypothesis.

本文从Navier-Stokes方程出发，导出不同形式的流动稳定性方程，包括采用小扰动理论得到的Orr-Sommerfeld方程、基于流向慢变特性而得到的抛物化稳定性方程以及在一小范围内计算的局部法方程。

The ammonia volatilizing of fertilizer is suit to the dynamic equation as Y=a+bt, the coefficients in the equation are related to the kind of fertilizer, temperature and water content of soil, and the dynamic equation about ammonia volatilization including water and temperature and the is developed. In addition, the dynamic equation about ammonia fertilizer affected by interaction of water and temperature is gotten.

肥料氨累积挥发量符合零级反应动力学方程Y=a+bt，方程中系数与肥料种类、温度和土壤含水量有关，碳铵a、b值均比硫酸铵高，土壤含水量增大，a、b值降低，温度升高，a、b值增大，并由此得到含温度或土壤湿度因子的肥料氨挥发动力学方程，并建立了含水、热因子的肥料氨挥发水热耦合效应动力学方程。

We can lead out the equivalent border integral equation by Green the second equation,dividing the inner border in the liquid into a series strip of awls shell or cylindrical shell ,and solve border integral equation along different segment of border, then lead out border integral equation.

由Green第二恒等式导出等价的边界积分方程，将液体内边界分成一系列锥壳或柱壳状条，对边界积分方程进行分段积分，导出边界元格式方程。

By the use of Circling cluster and Envlopment theory and flat surface sit-mark transformation theory, the chain wheel tooth equation of roller chain at high speed to match conjugage engagement is deduced.Establishing chain speed equation of roller chain at high speed,based on the analysis of the speed curves between roller chain at high speed and common roller chain,good drive of roller chain at high speed is verificated theoretically.By a example that move distance from transverse vibration between roller chain at high speed and common roller chain is contrasted,the accuracy of those theories that the paper brings up and higher functions of roller chain at high speed is proved.Finally, Establishing conjugage engagement line equation of roller chain at high speed and analyzing the complete engagement zone, the chain wheel tooth curve equation is studied at a higher degree. At the same time,the lack's place of the research result is pointed out.

依据高速滚子链设计要求与H_y-V_0齿形链的研究，阐述了滚子链传动实现准共轭啮合理论可能性；利用圆族包络法结合平面坐标变换理论推导出了满足共轭啮合的高速滚子链的链轮齿廓曲线；建立起高速滚子链链速方程，通过对高速滚子链与普通滚子链链速曲线的对比分析，从理论上验证了高速滚子链具有良好的传动性能；最后，建立起高速滚子链共轭啮合线方程，对其整个啮合区间进行了分析，进一步研究了链轮齿廓曲线方程，确定了主要参数的设计方法的问题，并同时指出了不足之处。

The basic concept in these sections is replacing backward Euler's method by modified backward Eulers's method to approximate the characteristic differential equation and discretizing the convection-diffusion equation at the middle point of the approximate characteristic curve, which will make the convective term get up to second order accuracy.

这三节的基本离散方法是用改进的Euler公式代替向后Euler公式来近似特征微分方程，并且将近似特征线的中点作为离散节点，使得对流项的离散精度提高到二阶，对于扩散项，将其转移到待求时间层进行离散。

It then deduces the associated Euler-Lagrange equation and established the corresponding diffusion equation. Finally, a finite difference inpainting algorithm is proposed.

根据所建立的修补模型，利用变分原理推导出对应的Euler-Lagrange方程，建立了与之对应的扩散方程。

The changes of the HAF after liver injury may be related to the volume of blood loss, the intraabdominal pressure and the pneumoperitoneum duration.

肝撞击伤伴失血后肝动脉血流量的变化与失血量、气腹压力以及气腹持续时间等有密切联系。

Reneging on our commitments to the world's poor cannot be an austerity measure, she said.

放弃我们给世界上的穷国的承诺不能成为一种紧缩措施。