查询词典 diffusion coefficient

It is a generalization of the nonlinear diffusion equation proposed by Perona-Malik and the method presented by Cuesta, and interpolates between the nonlinear parabolic equation and the nonlinear hyperbolic equation, thus can effectively control the diffusion process so that noises can be removed and details of the image such as edges can be preserved as much as possible simultaneously.

提出了一种包含对时间的分数阶导数的非线性扩散方程，它是对Perona-Malik的非线性扩散方程和Cuesta提出的方程的推广，介于非线性抛物方程和非线性双曲方程之间，从而能有效地控制扩散过程，使得在去除图像噪声的同时能够尽可能地保留图像的边缘等细节信息。

Many natural phenomena and physical laws can be described by time dependent nonlinear differential equations, such as heat conduction equation, sound wave and elastic wave equation, reaction diffusion and convection diffusion equation, fluid and aerodynamics equations, etc.

大多数的自然现象与物理规律都可归结为与时间相关的非线性偏微分方程，诸如热传导方程、声波与弹性波方程、反应扩散与对流扩散方程、流体与气体力学方程组等发展方程。

The diffusion of mass or heat across two phases is extensively involved in chemical processes. Because of the effect of this kind of diffusion, there will be a inhomogeneous distribution of material concentration and then a gradient of interfacial tension will be occured on the interface of the two phases. When the gradient tends to a certain value, the natural convection would be induced derivatively, and orderly convective cells would appear in the system simultaneously. This is the so-called Marangoni phenomenon.

在化工过程中，广泛涉及到两相间的质量或热量扩散，由于这种扩散的作用，将在相界面处产生物质浓度的不均匀分布，从而出现界面张力梯度，这种梯度达到一定值以后，将出现派生的自然对流运动，并且在系统中呈现有序的对流胞结构，这就是所谓的Marangoni现象。

Furthermore, social progress and IT advancement strengthen the urban spatial diffusion. Such diffusion effect and the increasingly constant exchanges between city and its surrounding areas accelerate the extension of city and the integration of urban and rural areas.

随着社会进步和和信息技术的发展，加强了城市的空间扩散能力，城市空间扩散的效应和城市与周边区域间的交流日益频繁，加快了城市向外的拓展，促进了城乡间的快速融合。

By automatically selecting the optimal diffusion constant and iterative number, the filtering process is totally automatic and does not require any operator assistance and the diffusion is suppressed or stopped at boundaries and edges and small structures are retained.

正是在这样的背景下，本研究针对计算机集成相控HIFU治疗计划中的两项关键技术：序列医学断层图像的分割及其体视化技术，进行了理论研究和算法的设计。

Illustrative results are presented for the radiation dose and dose profile with activity distributions: uniform, determined by steady-state diffusion into the target volume, or determined by steady-state diffusion with a constant rate of loss of activity from the target.

计算程序用Visual Basic V6.0编写，在微机上运行。为了验证计算结果，将均匀分布条件下的计算结果分别与文献报导的结果比较，发现它们是一致的。

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。

Gas diffusion electrode was applied in the reaction system in order to weaken control process of diffusion.

比较了两种方法制备的气体扩散电极对反应控制步骤的改进效果。

Analysis of its behavior shows that the generalized diffusion process combines properties of both forward and inverse diffusion.

其行为的分析表明，广义扩散过程结合了这两个属性正，逆扩散。

The hot-rolled composite is a diffusion process, and the diffusion range of the elements is about 50 μm.

热轧复合为扩散型冶金结合，元素扩散范围在50μm范围内。

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。