相关实验视频
Updated: Jun 30, 2026
10:56
Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 21, 2014
中子测绘聚合物流动:散射,流动可视化和分子理论.
J Bent1, L R Hutchings, R W Richards
1Department of Chemistry, Durham University, UK.
Science (New York, N.Y.)
|September 23, 2003
概括
了解复杂的流体流动需要检查宏观和分子尺度. 这项研究表明,在较大的尺度上,聚合物链的方向衰变速度比以前想象的要慢,这影响了质性质.
科学领域:
- 聚合物物理 聚合物物理
- 类风病学 类风病学 类风病学
- 复杂的流体动力学.
背景情况:
- 宏观流体的行为是由底层的分子相互作用决定的.
- 纠的聚合物化物表现出复杂的质性质,对于加工至关重要.
- 了解分子配置和宏观流动之间的相互作用是必不可少的.
研究的目的:
- 为了研究纠的聚合物融在延长收缩的流场.
- 为了将宏观应力场与微观聚合物配置相关联.
- 为了验证纠聚合物融流的管道模型理论.
主要方法:
- 光学成像用于探测宏观流动.
- 微角中子散射用于探测分子配置.
- 一种双探头技术,结合了这两种方法.
主要成果:
- 该研究成功地同时成像了流场和分子配置.
- 结果与来自管模型理论的预测进行了比较.
- 在考虑重复,轮长度波动和对流约束释放时,发现了定量一致.
结论:
- 基本纠的过程的联合作用对于准确的类风学预测是必要的.
- 一个新的发现是,大型聚合物链的方向衰变速度比纠长度的方向慢.
- 这种多尺度的方法为复杂的流体流动行为提供了更深入的见解.
相关概念视频
03:48Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion
Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...
01:11Relative Velocity in Two Dimensions
Relative velocity is the velocity of an object as observed from a particular reference frame, or the velocity of one reference frame with respect to another reference frame. The concept of relative velocity can be used to describe motion in two dimensions. Consider a particle P and two reference frames S and S′. The position of the origin of S′ as measured in S is , the position of P as measured in S′ is , and the position of P as measured in S is , which can be evaluated by utilizing vector...
01:27Distribution of Molecular Speeds
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...