查询词典 diffusion equation

Firstly, the diffusion of oxygen atom from the SFCC to SHCP on Zr(0001) surface is calculated. The active energy for the diffusion is 0.77eV. Secondly, the diffusion of oxygen atom from the SFCC to Octa(2,3) via Octa(1,2) is calculated too. There are 2 energy barriers for oxygen atom to overcome, the active energies are 2.14eV and 2.57eV.

我们首先计算了氧原子从稳定的表面面心立方位置向表面六角密排位置的扩散，其扩散激活能为0.77eV；然后计算了氧原子从稳定的SFCC位置扩散到表面下第1层与第2层之间的八面体间隙Octa(1，2)位置，然后继续向表面下第2层与第3层之间的八面体间隙Octa(2，3)位置扩散，在此过程中氧原子需克服2个能垒，其激活能分别为2.14eV和2.57eV。

Scholars both here and abroad widely accept that diffusional environment is one of the most important factors to influence green-technology diffusion. To eliminate or conquer green technology diffusion obstacles so that to promote green-technology's rapid and broad diffusion, most researchers bring forward a series of suggestions of improve diffusional environment.

尽管国内外学者普遍认同扩散环境是影响绿色技术扩散的重要因素，为减轻或克服绿色技术扩散壁垒，达到促进绿色技术快速、大范围扩散的目标，许多研究人员提出一系列改善扩散环境的建议。

Traditional theory of chemical diffusion in solid states can not describe the relation of diffusion fluxes and diffusion-induced stresses because the research subject of the traditional theory is the diffusing atom or atomic flux, not the volume unit in the interdiffusion field.

传统固体化学扩散理论的研究对象是扩散的原子或原子流，并不关心互扩散区域内微观体积单元的变化，因此无法描述原子扩散流与应力之间的关系。

In this paper,a space fractional differential equation is considered.The equation is obtained from the advection-diffusion equation by replacing the second order derivative in space by a fractional derivative in space of order.

考虑空间分数阶微分方程(即在一个标准的扩散-对流方程中，用分数阶导数代替空间二阶导数)，给出了该分数阶微分方程的显式和隐式有限差分格式。

Therefore,it is necessary to research diffusion equation for suspended sediment because it describes the sediment move process in the water body.The equation is a various coefficients second-order linear partial differential equa-tion,such equation under complex boundary condition is very difficult to get its analytical solution,while its numerical solution relative analytical solution is more easier and has the obvious superiority:simple,the computation convenience.but to get a kind of difference format which is good accuracy and stability is not easy.

泥沙扩散方程实际上是一个变系数的二阶线性偏微分方程，这样的方程在各种复杂边界条件下求解是十分困难的，求它的解析解在数学上存在着难以克服的障碍，无法求出其精确解，因此常用数值方法求它的近似解，相比较而言，数值方法有着明显的优势：即简单灵活、计算方便快捷，但要寻找一种精度高、稳定性好、计算方便的差分格式也并非易事。

According to the theory of flow diffusion and convection, three-dimensional state equation of radon field is established for constant and variable diffusion coefficient and convection rate. The numerical solutions for different coefficient and different boundary conditions are obtained for two models of radon field which have respectively source in the side and inside of collapse column.

根据流体场的扩散理论和对流理论，建立了扩散系数与对流速度为常量或变量情况下的氡气场三维状态方程；对於陷落柱柱体侧面有源氡气场和柱体体内有源氡气场两种理论模型，给出了不同系数和边界条件下的数值解的形式。

We also used diffusion equation to solve curren-time relation of ion diffusion under certain boundary conditions.

应用扩散方程，在一定的边界条件下解得电流注入过程中离子扩散的电流-时间关系。

After simplification of the Jou model,a diffusion dynamic equation, which was characterized with hyperbolic type, was obtained, then simulative analysis for three combined dimensionless parameters was done to research various diffusion behavior resulted from the change of model parameters.

经过对Jou模型的简化处理，得到了双曲型的扩散动力学方程，通过对模型中3个组合参数的仿真分析，研究了参数的变化可能导致的不同的扩散行为。

This dissertation firstly analyses the background of this project, then analyses the research status of the AIP submarine, the gas leakage diffusion models, the numerical value solution of the diffusion equation, and the simulation research progress.

本文首先分析了本课题提出的背景，接着分析了目前国内外关于AIP潜艇的研究现状、气体泄漏扩散模型、扩散方程的数值解法、仿真研究进展，在此分析基础之上确定了本文的研究内容。

It was found that sulfuric acid, 2-naphthalenesulphonic acid and sulfurous acid could be effectively separated by competitive exchange adsorption in views of action force difference of the components with the resin. The exchange adsorption dynamic diffusion parameters were calculated with diffusion equation for solids and liquid films, and the rate-determining step was determined. The model of breakthrough curve for the resin bed was suggested, and applied to simulate the breakthrough process for each component.

通过单组分、双组分和多组分平衡数据的测定，发现对于硫酸-萘磺酸-亚硫酸混合体系，可以利用不同组分与树脂作用能的不同，通过竞争交换吸附实现分离；以固相扩散方程和液膜扩散方程对交换吸附动力学参数进行了估算，确定了交换吸附过程的控制步骤；建立了床层穿透曲线模型，并对各组分穿透过程进行了模拟。

Sodium citrate; calcium carbonate; calcium hydroxide; potassium bicorbonate; magnesium carbonate; ferrous sulphate; Zinc sulphate; copper sulphate; manganese sulphate; potassium iodide; sodium selenite.

柠檬酸钠；碳酸钙；氢氧化钙；碳酸氢钾；碳酸镁；硫酸亚铁；硫酸锌；硫酸铜；硫酸锰；碘化钾；亚硒酸钠。

All this to say that I'm glad filmmaking hasn't become completely ironic. I can enjoy an ironic film as much as the next person, but they usually involve a message of some sort. One that's delivered in a smirkingly clever way that requires little in the way of talent.

所有这些都是说，我很高兴电影制作没有变成完全讽刺艺术，我可以和下一个人一样享受讽刺电影的乐趣，虽然他们经常会被划归到一定级别，技术方面不需要很高的才能。