速度波动对活跃磁盘集体动态的影响
1Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA. akhair@andrew.cmu.edu.
Soft matter
|October 4, 2023
概括
活跃磁盘可以通过反转其自我推进方向来避免集群. 这一发现无论速度变化是周期性的还是随机的,都适用,为活性物质悬浮提供了洞察力.
科学领域:
- 物理 物理学 物理
- 软物质物理学 软物质物理学
- 统计力学 统计力学
背景情况:
- 活性物质系统表现出集体行为,如运动性诱导相分离 (MIPS).
- 活性粒子的动力学受到自行推进速度和方向的影响.
- 了解活性物质的相变对于设计新型材料和设备至关重要.
研究的目的:
- 研究具有时间变化的自动推进速度的活性磁盘的集体动力学.
- 探索如何确定性和随机速度变化,加上方向逆转,影响相位分离.
- 确定在活跃磁盘系统中可以避免或诱导MIPS的条件.
主要方法:
- 活跃磁盘经历旋转布朗运动的数值模拟.
- 对于时间变化的自动推进速度,有两种不同的协议:周期性 (频率 ω) 和随机性 (功率定律分布与速率 β).
- 在不同频率和逆转条件下分析系统状态 (集群与同质).
主要成果:
- 确定性速度变化的增加频率 (ω) 在自我推进方向逆转时,促进从集群到同质状态的过渡.
- 随机速度变化也导致较大的集群解体,允许方向逆转.
- 阶段分离可以通过允许自动推进方向逆转来抑制,无论时间协议如何.
结论:
- 自动推进方向的反转是防止活性物质悬浮中运动性诱导的相分离的关键.
- 即使没有净个体运动,也可以发生相分离,如果方向逆转速率低于方向扩散速率.
- 这些发现为控制活性物质系统中的自我组装和宏观模式提供了一条途径.
更多相关视频
11:51Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
8.7K
11:03An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
8.6K
相关概念视频
01:27Distribution of Molecular Speeds
4.0K
The motion of molecules in a gas is random in magnitude and direction for individual molecules, but a gas of many molecules has a predictable distribution of molecular speeds. This predictable distribution of molecular speeds is known as the Maxwell-Boltzmann distribution. The distribution of molecular speeds in liquids is comparable to that of gases but not identical and can help to understand the phenomenon of the boiling and vapor pressure of a liquid. Consider that a molecule requires a...
4.0K
01:23Electric Field of a Charged Disk
2.2K
The simplest case of a surface charge distribution is the uniformly charged disk. Calculating its electric field also helps us calculate the electric field of a large plane of charge.
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
2.2K
01:23Faraday Disk Dynamo
2.3K
A Faraday disk dynamo is a DC generator, producing an emf that is constant in time. It consists of a conducting disk that rotates with a constant angular velocity in the magnetic field, perpendicular to the disk's plane. The rotation of the disk causes a change in magnetic flux, which induces an emf, causing opposite charges to develop on the rim and in the center of the disk. The polarity of the induced emf can be determined by the direction of the magnetic field and the direction of the...
2.3K
01:30Dynamics of Circular Motion
13.6K
An object undergoing circular motion, like a race car, is accelerating because it is changing the direction of its velocity. This centrally directed acceleration is called centripetal acceleration. This acceleration acts along the radius of the curved path (thus is also referred to as radial acceleration).
Any acceleration must be produced by some force. Therefore, any force or combination of forces can cause centripetal acceleration. A few examples include the tension in the rope on a...
Any acceleration must be produced by some force. Therefore, any force or combination of forces can cause centripetal acceleration. A few examples include the tension in the rope on a...
13.6K
01:20Types of Damping
6.5K
If the amount of damping in a system is gradually increased, the period and frequency start to become affected because damping opposes, and hence slows, the back and forth motion (the net force is smaller in both directions). If there is a very large amount of damping, the system does not even oscillate; instead, it slowly moves toward equilibrium. In brief, an overdamped system moves slowly towards equilibrium, whereas an underdamped system moves quickly to equilibrium but will oscillate about...
6.5K
01:17Magnetic Damping
477
Eddy currents can produce significant drag on motion, called magnetic damping. For instance, when a metallic pendulum bob swings between the poles of a strong magnet, significant drag acts on the bob as it enters and leaves the field, quickly damping the motion.
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
477