相关实验视频
Updated: Jun 4, 2025
08:52
Characterizing Electron Transport through Living Biofilms
Published on: June 1, 2018
8.4K
在地质相关的导电场中随机散步的统计数据
Shayan Jalalmanesh1, Muhammad Sahimi1, Felipe P J de Barros2
1Mork Family Department of Chemical Engineering and Materials Science, <a href="https://ror.org/03taz7m60">University of Southern California</a>, Los Angeles, California 90089-1211, USA.
Physical review. E
|December 18, 2024
概括
这项研究表明,在多孔介质中随机走路的统计数据取决于液压导电量的分布. 异常扩散发生在导电量分布广泛时,偏离标准模型.
科学领域:
- 物理 物理学 物理
- 地质物理学 地质物理学
- 应用数学 应用数学 应用数学
背景情况:
- 随机步行模型在各种媒体中扩散,为不同的访问站点和返回概率建立了权力规律.
- 之前的研究假定了统一的债券导电量,这限制了适用于多孔介质等异质系统的适用性.
研究的目的:
- 调查分布广泛的液压导电量如何影响多孔介质中的随机步行统计数据.
- 确定是否普遍的电力规律适用于异质地质媒体中的扩散.
主要方法:
- 广泛的蒙特卡洛模拟2D网格上的随机步行.
- 考虑五个地质相关的导电分布:正常,日志-正常,分数布朗运动 (FBM),日志-FBM和稳定分布.
- 关键扩散统计的分析:访问的不同地点的平均数量S(t),返回原点的平均概率P0(t),和平均平方位移
主要成果:
- 随机步行统计,包括指数p和 ζ对于S{\displaystyle S}t和P{\displaystyle P}t,取决于导电分布.
- 在至少三种分布中,扩散是异常的,
- 指数不同于同质格子和碎形结构中发现的指数.
结论:
- 在高度异质的多孔介质中扩散是异常的.
- 随机走路的统计数据对底层导电分布敏感.
- 在地质介质中的异常扩散可以用分数局部微分方程来描述,其顺序取决于导电分布的细节.
相关概念视频
01:17Theory of Metallic Conduction
1.3K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.3K
01:13Electrical Conductivity
1.1K
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
1.1K
01:17Wald-Wolfowitz Runs Test II
179
The Wald-Wolfowitz runs test, commonly referred to as the runs test, is a nonparametric test used to assess the randomness of ordered data. The test evaluates the number of runs, which are consecutive sequences of similar elements within the data. If the number of runs is significantly higher or lower than expected, the data is considered non-random, indicating a detectable pattern or structure.
For binary data, runs are identified using symbols such as + and −, or equivalently, 1s and...
For binary data, runs are identified using symbols such as + and −, or equivalently, 1s and...
179
01:21Carrier Transport
401
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
401
01:19Drift Velocity
4.0K
The high speed of electrical signals results from the fact that the force between charges acts rapidly at a distance. Thus, when a free charge is forced into a wire, the incoming charge pushes other charges ahead due to the repulsive force between like charges. These moving charges move the charges farther down the line. The density of charge in a system cannot easily be increased, so the signal is passed on rapidly. The resulting electrical shock wave moves through the system at nearly the...
4.0K
01:17Wald-Wolfowitz Runs Test I
604
The Wald-Wolfowitz test, also known as the runs test, is a nonparametric statistical test used to assess the randomness of a sequence of two different types of elements (e.g., positive/negative values, successes/failures). It examines whether the order of the elements in a sequence is random or if there is a pattern or trend present. This nonparametric test applies to any ordered data despite the population and sample data distribution, even if a higher sample size is available.
The test works...
The test works...
604