查询词典 diffusion

For convection dominated diffusion equations with constant coefficients, the implicit scheme is consistent,unconditionally stable and its L~2 error estimation is derived.

对常系数的对流占优扩散方程而言，基于一边有限差分和中心差分的隐格式是相容的并且无条件稳定，对应L~2误差估计被推导。

The purpose of this thesis is to present a direct perturbative method to solving certain Fokker-Planck equation, which have constant diffusion coefficients and some small parameters in the drift coefficients.

中文摘要本篇论文应用微扰法来解某些Fokker-Planck方程式，而这种Fokker- Planck方程式具有扩散系数是常数以及漂移系数是很小的参数的特徵。

Using the probability relaxation model,we obtainedthat the diffusion constant and the relaxation time have the same temperaturedependence,denoting our view is correct.

分子动力学模拟计算的扩散系数和弛豫时间都遵从Vogel-Fucher关系，进一步支持了过冷液体的非指数弛豫的粒子逃离笼子的机制。

In the second part, a method studying stochastic transition which is the master equation method is introduced, and explicit solutions of velocity V and diffusion constant D of the steady state are obtained when a particle hops among a dimensional and periodic N states.

第二部分介绍了一种研究随机跃迁的方法—主方程方法，着重推导了粒子做一维周期性N态随机跃迁时达到稳态的速度、扩散系数的一般表达式。

In HgCdTe with low dislocation density, the main component is a Guassian like distribution and can be described by the Fick's law with a constant diffusion coefficient with a limited source as the boundary condition.

在缺陷密度比较低的碲镉汞材料中，砷扩散的主体符合恒定扩散系数的有限源扩散模型，呈现出浓度随深度的高斯分布。

The model was used to fit the release profiles of the above three different actives, and the diffusion coefficient and dissolution rate constant were obtained. Based on the modeling study, the relationship of porous microspheres structure, actives performances and release behavior was found, hence a theoretical basis was provided to optimize the microsphere synthesis and desired actives release profile.

采用提出的模型对三种活性物的体外释放实验数据进行拟合，求得不同活性物的有效扩散系数和溶解速率常数，揭示了微球结构、活性物性质和释放性能关系的一些基本规律，为指导微球合成、改善和控制活性物的释放性能提供了基础。

In order to exploit this effect to enhance diffraction efficiency, experiments of non-continuous holographic exposure were designed and conducted, The diffusion time constant of the material was obtained to be 21 s by fitting the experimental data of dark enhancement with theoretical model.

为了利用暗增长过程提高衍射效率，设计并实施了非连续曝光实验，使曝光与暗增长过程交替进行。

The features of this dissertation are lie in: a The concept of"Influence Distance"was presented to quantitatively express"corner effect", systematicly studied on the influence of all factors on"influence distance". It could provide reference to angle designing from the view of heat treatment; b Deeply studied on the influence of shape factor to carbon concentration field. It could provide reference to gear designing from the view of heat treatment; c New model was set up to describe the two-dimensional concentration field of carbide dispersion carburizing. The shortcomings of"effective diffusion constant method"and"equilibrium constant method"were overcome in this model.

本文的特色在于：①提出了用"尖角影响距离"定量描述"尖角效应"的方法，并系统研究了各种因素对"尖角影响距离"的影响规律，从热处理角度为工件尖角部位的设计提供依据；②首次深入研究了齿轮的各种形状因素对浓度场的影响，从热处理角度为齿轮设计提供依据；③建立了能够更有效地模拟过饱和渗碳浓度场的数学模型，该模型克服了"有效扩散系数法"及"平衡常数法"的不足，与"最小自由能法"可互为补充。

A fundamental solution for the linear case of the complex diffusion equation is developed.

一个复杂的线性情况下根本的解决办法扩散方程的发展。

And this paper introduces the optimal control problem for the assets evolution equation with diffusion term.

第三节，给出本文的总结，并介绍了带有扩散项的资产发展方程的最优控制问题。

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。