查询词典 diffusion equation

Chapter 2 is devoted to study of exact solutions of the nonlinear evolution equations. Using solutions of a Bernoulli equation instead of tanh in tanh-function method we find some more general solutions of the KdV-Burgers-Kuramoto equation , and by using the nonlinear telegraph equation we show that there are many different choices on its balancing number m and the power n of the nonlinear term in Bernoulli equation by which we can recover the previously known solutions and also can derive new square root type solitary wave solutions. Exact solitary wave solutions for a surface wave equation are obtained by means of the homogeneous balance method. We also present an approach for constructing the solitary wave solutions and non-solitary wave solutions of the nonlinear evolution equations by using the homogeneous balance method directly, which is also used to find the steady state solutions, solitary wave solutions and the non-solitary wave solutions of the 2+1 dimensional dispersive long wave equations. The soliton-like solutions of the BLMP equation and the 2+1 dimensional breaking soliton equation are found by use of the symbolic-computation-based Method.

第二章中研究了非线性发展方程的精确解：用双曲正切函数法中的双曲正切函数换为Bernoulli方程的解的方法而给出KdV-Burgers-Kuramoto方程的精确解并用非线性电波方程为例说明了平衡数m和Bernoulli方程中非线性项的次数n有着多种选择的可能，它不但使我们能找到已知解而且也能找出新的根式孤立波解；用齐次平衡法给出一个曲面波方程的精确孤立波解，并提出直接用齐次平衡法寻找非线性发展方程的孤立波解、非孤立波解的方法，作为应用给出2+1维色散长波方程组等的定态解、孤立波解、非孤立波解等；用Symbolic-computation-basedMethod获得BLMP方程和2+1维破裂孤子方程的类孤子解；提出sine-Gordon型方程的直接求解方法，并获得sine-Gordon方程、双sine-Gordon方程、sinh-Gordon方程、MKdV-sine-Gordon方程和Born-Infeld方程等的精确孤立波解。

The microstructure evolution and composition distribution of the 7A55 cast and homogenized alloy were studied by optical microscopy, scanning electron microcopy, energy dispersive spectrometer, transmission electron microscopy and X-ray diffractometry. The homogenizing and overburnt temperatures of the alloy were determined. Meanwhile, the diffusion kinetics of the alloy elements during homogenizing treatment was investigated and the homogenizing kinetic equation was deduced according to Fick's First Law of diffusion. The diffusion of alloy elements, precipitation of Al3Zr particles and the conglomeration and globe of the insoluble phases were explained by the equation during homogenization.

摘 要：采用光学显微镜、扫描电镜、能谱分析、透射电镜和X射线衍射分析等研究了7A55合金铸态与均匀化显微组织演化与成分分布，确定了该合金的均匀化处理温度与过烧温度，研究了铸锭均匀化动力学过程，利用菲克定理导出了均匀化动力学方程，利用动力学方程对均匀化过程中合金元素的扩散、 Al3Zr的析出、难熔相的聚集和球化现象进行了解释。

Diffusion problem of a predator-prey model with Holling typeⅡfunctional capturing function is studied. Stability condition is obtained when diffusion is absent, and the effect on stability of positive equilibrium is studied when diffusion is present. In the end, the problem of existence of limit cycle is proved in the first quadrant when diffusion is absent.

针对一类具有HollingⅡ型功能捕获函数的捕食－食饵模型的扩散问题进行了研究，得到了无扩散时正平衡点的稳定条件，以及扩散存在时对正平衡点稳定性产生的影响，最后证明了无扩散时系统在第一象限存在极限环的问题。

This dissertation involves the study of the growth dynamics of colloidal particles under unequilibrium and irreversibility condition. Firstly, it is of interest to investigate whether the ideal diffusion or reaction-limited aggregation universal behavior can be observed for the initially polydisperse practical system of basic yttrium carbonate as well. The fractal structure of basic yttrium carbonate aggregate cluster was observed using transmission eletron microscopy. The aggregation kinetics of basic yttrium carbonate colloids was studed using dynamic 1ight-scattering techniques. At 1.00mol/l NaCl solution the fast diffusion-limited aggregation behavior was observed with an increase in the aggregate size over time described by a power law. The aggregates are characterized by a fractal dimension D=1.82. The disordered and ramified cluster is consisted of primary colloidal particles and tenuous and more open. These are in good agreement with those observed for other colloidal system such as colloidal gold (1.86), silica (1.85) and polystyrene latex (1.82) in diffusion-limited aggregation from the static and dynamic light scattering by Lin. Therefore ideal diffusion-limited aggregation behavior can be observed in practical polydisperse system as well. Smoluchwski and fractal theories were used to obtain the aggregation rate constant for initially polydisperse system for the first time.

本论文研究胶粒的非平衡不可逆聚集动态学，分为两个部分，第一部分是通过实验研究一个新的初始多分散的碱式碳酸钇胶粒实际体系中，聚集标度性质的普适性，即使用透射电子显微技术观测聚集粒子簇的分形结构，使用动态激光光散射研究碱式碳酸钇胶粒的聚集动力学，胶粒带电而产生静电排斥作用使得碱式碳酸钇胶粒处于稳定状态，当加入电解质NaCl溶液时，碱式碳酸钇胶粒间的Debye-Hückel屏蔽距离缩短，从而降低静电排斥能垒，引起胶粒发生不可逆聚集，加入电解质NaCl的浓度为1.00mol/l时，碱式碳酸钇胶粒进行快速聚集，经历扩散控制聚集机理，形成结构疏松、更为开放的分形聚集粒子簇，其分形维数为1.82，碱式碳酸钇胶粒聚集增长动力学遵循幂函数增长规律，与Lin等使用静态激光光散射和动态激光光散射测量硅胶(1.85)、金胶(1.86)和聚苯乙烯胶乳(1.82)在扩散控制聚集状态形成聚集粒子簇的分形维数值以及粒子簇聚集增长的动力学规律相一致，表明胶粒聚集标度性质的普适性质在初始多分散的实际体系中也是存在的，首次由动态激光光散射的实验数据得到初始多分散胶粒分形粒子簇的聚集速率常数，并且其值与Smoluchowski聚集速率理论预期相符。

Diffusion tensor imaging is a kind of new technique after diffusion weighted imaging.DTI can reflect anisotropy hydrone molecular diffusion features of damaged myeloid tissue through measuring apparent diffusion coefficient and fractional anisotropy.Accordingly,we can make more precise and allround estimate about spinal compression on microscopic scale.

磁共振扩散张量成像是继扩散加权成像后发展起来的一种新技术，它通过测量表观扩散系数及部分各向异性值来反映损伤脊髓组织的各向异性水分子扩散特征，从而在微观水平对脊髓压迫症做出更精确和全面的评价。

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。

Finally, in the third section, by constructing some functional which similar to the conservation law of evolution equation and the technical estimates, we prove that in the inviscid limit the solution of generalized derivative Ginzburg—Landau equation converges to the solution of derivative nonlinear Schrodinger equation correspondently in one-dimension; The existence of global smooth solution for a class of generalized derivative Ginzburg—Landau equation are proved in two-dimension, in some special case, we prove that the solution of GGL equation converges to the weak solution of derivative nonlinear Schr〓dinger equation; In general case, by using some integral identities of solution for generalized Ginzburg—Landau equations with inhomogeneous boundary condition and the estimates for the L〓 norm on boundary of normal derivative and H〓 norm of solution, we prove the existence of global weak solution of the inhomogeneous boundary value problem for generalized Ginzburg—Landau equations.

第三部分：在一维情形，我们考虑了一类带导数项的Ginzburg—Landau方程，通过构造一些类似于发展方程守恒律的泛函及巧妙的积分估计，证明了当粘性系数趋于零时，Ginzburg—Landau方程的解逼近相应的带导数项的Schr〓dinger方程的解，并给出了最优收敛速度估计；在二维情形，我们证明了一类带导数项的广义Ginzburg—Landau方程整体光滑解的存在性，以及在某种特殊情形下，GL方程的解趋近于相应的带导数项的Schr〓dinger方程的弱解；在一般情形下，我们讨论了一类Ginzburg—Landau方程的非齐次边值问题，通过几个积分恒等式，同时估计解的H〓模及法向导数在边界上的模，证明了整体弱解的存在性。

The equation for item level from item slot is a logarithmic equation and the equation from item level to weapon DPS would require an exponential equation, therefore an equation from item slot value, the value prior to item level, to weapon DPS would be a linear equation.

武器DPS是物品等级中一个很有趣的属性，因为它似乎有多种计算方法。最近加入的传家宝物品可以提出和回答这个问题。物品等级在57以前的时候，它的计算方法和蓝装的线形公式一样，传家宝武器不是线形增长的，似乎是介于线形和多项式增长之间。在58-67的时候，传家宝武器的DPS随物品等级成指数增长。在68-80的时候，武器DPS也是成指数增长，但是速度不同。在100-226之间的史诗物品成相同的指数增长。

The asymptotical properties of KdV equation and KP equation exhibit the soliton behavior when some conditions are satisfied, and in some cases the parameter matrices describing the interaction between two solutions is quite simple. Two kinds of solutions of the second coupled equations of AKNS hierarchy are provided and applied to NLS equation. A systemical way of construction of special solutions is also tried for DS equation. Most of the results on a scalar equation can often be directly generalized to some matrix equation, and the difference between the ω in scalar form and ω in matrix form lies only in the replacement of vector p, q by matrices p, q.

对KdV方程和KP方程渐近性质的讨论显现出解在一定条件下的孤子特性，从而使得一些情形下，同类解的相互作用体现在参数矩阵上变的较简单；我们给出了AKNS方程的两类不同解，并约化到NLS；对DS方程，我们从另一个方面初步探讨了形式化推导矩阵方程特解的方法；把这些有关标量ω的结果推广到ω为矩阵上往往只要把p，q变为矩阵即可，进而可以再推广到方程组上。

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。