Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Divergence and Curl of Magnetic Field01:26

Divergence and Curl of Magnetic Field

2.8K
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
2.8K
Atomic Nuclei: Nuclear Magnetic Moment00:59

Atomic Nuclei: Nuclear Magnetic Moment

1.0K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.0K
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

622
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis.
622
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

866
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
866
Magnetic Field Lines01:19

Magnetic Field Lines

4.0K
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
4.0K
Magnetic Field due to Moving Charges01:23

Magnetic Field due to Moving Charges

8.4K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
8.4K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Comprehensive analysis of the elemental composition and isotope ratios of honeys from US East Coast.

Food chemistry·2026
Same author

Isotope analyses reveal chronological and bioarchaeological consistency at a tribal community of the Sântana de Mureș-Chernyakhov culture in Transylvania.

Scientific reports·2026
Same author

Murder in cold blood? Forensic and bioarchaeological identification of the skeletal remains of Béla, Duke of Macsó (c. 1245-1272).

Forensic science international. Genetics·2025
Same author

Isotope and archaeobotanical analysis reveal radical changes in mobility, diet and inequalities around 1500 BCE at the core of Europe.

Scientific reports·2025
Same author

Macroscopic transport in mixed phase space Hamiltonian systems and the role of a distinct time-scale for the power-law decay.

Chaos (Woodbury, N.Y.)·2024
Same author

[Outlines - Vivian Maier's self-portraits].

Psychiatria Hungarica : A Magyar Pszichiatriai Tarsasag tudomanyos folyoirata·2024

相关实验视频

Updated: Jun 4, 2025

Magnetic Tweezers for the Measurement of Twist and Torque
11:41

Magnetic Tweezers for the Measurement of Twist and Torque

Published on: May 19, 2014

23.2K

显式依赖时间的无地图中的磁性结构.

Dániel Jánosi1,2, Anikó Horváth1, Lili Édes3,4

  • 1Department of Theoretical Physics, Eötvös Loránd University, 1117 Pázmány Péter sétány 1A, Budapest, Hungary.

Chaos (Woodbury, N.Y.)
|December 19, 2024
PubMed
概括

托卡马克中的等离子磁结构在被时间变化的参数的ergodic磁极限器扰动时变得混乱. 这项研究揭示了混乱过渡和利亚普诺夫指数的权力定律关系,提供了对等离子体限制的见解.

更多相关视频

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements
08:50

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

Published on: May 12, 2023

2.0K
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.5K

相关实验视频

Last Updated: Jun 4, 2025

Magnetic Tweezers for the Measurement of Twist and Torque
11:41

Magnetic Tweezers for the Measurement of Twist and Torque

Published on: May 19, 2014

23.2K
High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements
08:50

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements

Published on: May 12, 2023

2.0K
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.5K

科学领域:

  • 等离子体物理学的物理学
  • 非线性动力学是一种非线性动力学.
  • 统计力学 统计力学

背景情况:

  • 托卡马克磁性结构对于等离子体限制至关重要.
  • 埃尔戈迪磁极限器用于控制等离子体的行为.
  • 了解动态系统中向混乱的过渡是必不可少的.

研究的目的:

  • 为了研究非adiabatic参数变化对托卡马克磁性结构的影响.
  • 为了模拟ergodic磁极限器电流随时间变化的影响.
  • 分析扰动磁系统中向混乱的过渡.

主要方法:

  • 使用Ullmann-Caldas nontwist地图,显式时间依赖.
  • 适用于参数漂移的混乱哈密尔顿系的应用工具.
  • 追踪轨迹组合 (快照 tori) 并分析它们的演变.
  • 计算利亚普诺夫指数和识别混乱过渡的关键时刻.

主要成果:

  • 快照Tori在参数漂移时呈现时间依赖的形状.
  • 观察到一个向混乱的过渡,其特点是正的利亚普诺夫指数.
  • 在莱普诺夫指数,临界瞬间和参数漂移率之间发现了实证的权力规律关系.
  • 利亚普诺夫指数增加,而临界瞬间随着漂移率的增加而减少.

结论:

  • 一致的磁结构 (tori,岛屿) 倾向于随着扰动的增加而分裂成混乱,类似于恒定扰动.
  • 持续的参数漂移允许一些结构比静态扰动场景持续更长时间.
  • 这些发现提供了关于在不同时间条件下的托卡马克磁场扰动动态的见解.