查询词典 diffusion equation

This thesis consists of three chapters .In chapter one , the distributions of the last exit time and the corresponding results of Brownian motion in Markov process are introduced ,and previous remarkable achievements on the excursion of Brownian motion are numerated too ,also ,we introduce the main results and the history of elliptic diffusion process; In chapter two ,we summarily describe the excursion in Markov process and the result of the first hitting time of the elliptic diffusion process ; In last chapter ,we study estimates for the distributions of above three maximum excursions and minimum excursion in the elliptic diffusion process on R (d≥3), which leads the excursion of Brownian motion on ball on R (d≥3) to become a particular case .

全文共分三章，第一章介绍对称Markov过程中布朗运动的未离时分布及相关研究结果，列举了前人对布朗运动的游程问题的研究成果，并用较多篇幅介绍了一类特殊且非常重要的扩散过程——一致椭圆扩散过程的研究历史和本文的主要研究结果；第二章介绍Markov过程有关停时及游程的概念，叙述了一致椭圆扩散过程的定义，并给出了一致椭圆扩散过程有关首中时的结果；第三章是本文的核心部分，详细讨论了暂留一致椭圆扩散过程关于R~d(d≥3)上球的三类极大游程和极小游程的分布估计，使得布朗运动关于球的游程问题成为特例。

It implies that the diffusive atoms teaseling along a dislocation pipe may diffuse outward into the bulk material for diffusion and may again diffuse into another dislocation pipe to continue this sequence of diffusion processes, showing a complex diffusion course.

它意味着，这时在一个位错管内运动的扩散原子，可以离开位错管渗透到晶体中继续扩散，还可以又回到另一个位错管中作扩散运动，从而表现出一个复杂的扩散过程。

Meanwhile, by modeling the sewage diffusion, it is found that the range of the Changjiang Estuary sewage diffusion area can reach the East Chongming Bank, the Deep water Channel, and the Nanhui Bank, while the COD concentration near Meimaosha is especially high so that the sewage diffusion constitutes a threat to the water quality of Meimaosha area.

同时，通过对污染物扩散的数值模拟，本文发现长江口污染物的扩散范围能够到达崇明东滩、深水航道和南汇边滩，而没冒沙附近区域的COD浓度更是尤其地高，所以污染物扩散对没冒沙地区的水质也形成了一定的威胁。

The results show that, by plane spacing of holes in the distribution of gas diffusion layer of the fuel cell components, the performance of the higher than normal diffusion layer components battery performance because of the plane hole spacing distribution of the gas diffusion layer can improve the adoption of its liquid water, and improve the passage of air, thereby improving battery performance.

结果表明，由平面内孔隙率间隔分布的气体扩散层组成的燃料电池，其性能高于由普通扩散层组成电池的性能，因为平面内孔隙率间隔分布的气体扩散层都能够提高其液态水的通过能力，提高气体的通过能力，从而提高电池的性能。

A drain diffusion layer connected to an output end of the internal circuit is formed in one of two diffusion regions of the surface of the semiconductor substrate that are defined by the gate electrode, and a source diffusion layer grounded is formed in the other region.

与内电路输出端相连的漏扩散层形成在由栅电极确定的半导体基片表面的两扩散区之一的区内，而接地的源扩散层形成在另一区内。

The new model adapts an operator like coherence enhancement diffusion for edge orientation, and defines eigenvalues based on edgers orientation such that the new tensor has positive diffusion coefficient in edge direction and negative diffusion coefficient in gradient direction.

采用类似相干增强扩散的边缘定向算子实现对边缘的定向，然后根据边缘定向的结果设置扩散张量的特征根，使扩散张量沿边缘方向为正向扩散以增强边缘，而垂直于边缘方向为逆扩散以锐化边缘。

The effect of solidgrain diffusion was reflected by f0. The core diffusion could be excluded by minishing theparticle scales, but the solid grain diffusion could not.

在常见幂函数形式的速率方程中引入修正系数f0体现了固体扩散对反应的影响，说明减小催化剂粒径，只能排除孔扩散的影响，并不能排除固体扩散对反应的影响。

The results show that, the chloride concentrations and diffusion coefficients are both a one-humped function of elevations (can also be the time scale of seawater infiltration), they increase with the increase of elevation until they get to the peak value, and then decrease with the increase of elevation; an evident relationship is being between the surface chloride concentrations and the wave forces acted on the concrete surface, while there is no much difference among the diffusion coefficients; the diffusion coefficients get to bigger as the depth from the concrete surface increase in the influence of the capillary structures evolution and chloride concentration, but this tendency of change was alleviated with the increase of depth.

研究结果表明：氯离子侵蚀混凝土设施的竖向分布规律为氯离子浓度、扩散系数与标高之间同为单峰函数分布，先随高程变大而变大，达到峰值后，随高程变大而减小；氯离子侵蚀混凝土设施的环向分布规律为混凝土构件表面氯离子浓度、氯离子通量与波浪力之间有明显的对应关系，波浪力越大，则表面氯离子浓度和氯离子通量越高，而扩散系数在各方位角差别不明显；由于混凝土长期服役过程中内部毛细孔隙结构演化以及氯离子浓度的影响，氯离子扩散系数随混凝土深度变大而变大，但这种变化趋势随深度逐渐趋缓。

The effects of electroplated Ni layer and electroless plated Ni-P layer on the diffusion behavior in Sn-Ag/Cu solder joint were studied. The results by EPMA analysis showed that the electroless plated Ni-P layer acted as a good diffusion barrier between Sn-Ag solder and Cu substrate. However, the electroplated Ni layer can not hinder the inter-diffusion and reaction between molten Sn-Ag solder and Cu substrate when reflowing, and there was a layer of IMC (Cu6Sn5) at interface of Sn-Ag/C u solder joint.

摘 要：研究了电镀Ni层和化学镀Ni-P合金层对Sn-Ag/Cu焊点扩散行为的影响，电子探针分析表明：化学镀Ni-P合金层能很好地阻止Sn-Ag/Cu焊点在焊接过程中的Cu，Sn互扩散和相互反应；而电镀Ni层则不能阻止Sn-Ag/Cu焊点在焊接过程中的Cu，Sn互扩散和相互反应，界面反应产物仍以Cu6Sn5为主。

The improved model possesses band-pass filer characteristic, diffuses processing stability and satisfies the max-min principle. The simulation results show that the median filter is only proper for outlies noise and removes the thin line and corners of image. The linear filter extends or blurs the boundary of image. The anisotropic diffusion removes random noise effectively, but it brings about illusive edge and back diffusion for outlies noise. The improved model that possesses both median filter characteristics and anisotropic diffusion capability is proper for various mixed noise and can sufficiently protect the detailed characteristic such as corner, thin line and edge.

研究结果表明：中值滤波作为一种经典的非线性滤波方法仅适合于&飞点&噪声的滤波并引起图像的角点、线条损失，线性滤波扩大或使图像边界范围模糊；传统的各向异性扩散能对随机噪声有效地压制，但对&飞点&噪声会产生虚假的边缘甚至反扩散，而改进模型既具有中值滤波的特性又具有传统各向异性扩散的性能，适合于平滑不同强度与形状的混合噪声，并对角点、线条、边缘等细节信息提供足够保护。

In the chapter 2, the theoretic knowledge about the photosensitive resin and the grinding tools was firstly introduced.

第二章阐述了光固化树脂结合剂磨具的相关理论研究。

Do not use the program's indenting or margin-setting features; these will be added during typesetting.

不要使用缩排，页面边缘设置之类的选项，偶看不大懂。