其中,dx=limΔt→0(xt+Δt−xt), f(⋅,t):Rd→Rd 是drift coefficient(向量函数),g(⋅,t) 是diffusion coefficient(标量函数),w 是标准维纳过程(标准布朗运动),dw 可以看作是无限小的白噪声。 SDE 方程中 f,g 的设置并不是固定的,而是人为设计的。后面我们会看到,其实 NCSN 和 DDPM 本质上就...
G. Diffusion Coefficient-Formula Weight Correlation Analysis via Diffusion-Ordered Nuclear Magnetic Resonance Spec- troscopy (DOSY NMR) to Examine Acylglycerol Mixtures and Biodiesel Production. Energy Fuels 2010, 24, 4518-4521.Socha AM, Kagan G, Li W, et al. Diffusion coefficient-for- mula ...
其中f(\cdot) 被称为 漂移系数 (drift coefficient),g(t) 被称为 扩散系数 (diffusion coefficient),\boldsymbol{w} 是一个标准的布朗运动,\mathrm{d}\boldsymbol{w} 就可以被看成是一个白噪声。这个随机微分方程的解就是一组连续的随机变量 \{\boldsymbol{x}(t)\}_{t\in[0, T]},这里 t 就是把...
A Diffusion Coefficient is defined as a parameter related to the size and shape of a molecule and the viscosity of the solvent. It provides an estimate of the radius of a particle based on specific formulas for different shapes such as spheres and ellipsoids. ...
美 英 un.扩散系数;扩散率 英汉 网络释义 un. 1. 扩散系数 2. 扩散率 释义: 全部,扩散系数,扩散率
The Darcy permeability is similar to the diffusion coefficient, which represents the viscous resistance of a solid material to fluid flow under a pressure gradient, and is related to the microstructure of the solid skeleton and the viscosity of the fluid. ...
The density dependence of the self-diffusion coefficient of liquid methane electron channelingSelf-diffusion coefficients for liquid methane obtained by the NMR spin-echo technique are reported at 110, 140 and 160 K. The density ... Harris, K.R.,Trappeniers, N.J. - 《Physica A Statistical ...
The effect of stress on the diffusion of water in glassy polymers is analytically treated. Utilizing the free volume concept the effect of stress on the free volume fraction is established and in turn is related to the diffusion coefficient yielding the following formula: Dσ = Doe(6 to 10)...
The expressions for effective diffusion coefficient are obtained in the mean field approximation for two-phase system for spatial dimensions of 1, 2 and 3. The existence of potential barrier for diffusion on the phase boundary was taken into account via the boundary conditions. Obtained formulae co...
Multiparametric MRI for detection of radiorecurrent prostate cancer: added value of apparent diffusion coefficient maps and dynamic contrast-enhanced images Multiparametric magnetic resonance imaging (mp-MRI) is increasingly advocated for prostate cancer detection. There are limited reports of its use in th...