花在飞行过程中形成一个分离的旋转环
Cathal Cummins1,2,3, Madeleine Seale2,3,4, Alice Macente2,4,5
1School of Engineering, Institute for Energy Systems, University of Edinburgh, Edinburgh, UK.
Nature
|October 19, 2018
概括
花种子使用独特的旋转环来散发风. 这一空气动力学发现揭示了生物和工程系统的新流体行为类.
科学领域:
- 流体动力学
- 生物物理
- 航空动力学
背景情况:
- 风驱散的植物使用专门的结构来散播种子.
- 常见的公花使用子来增强种子的飞行.
- 这种种子飞行的物理原理尚未完全被理解.
研究的目的:
- 为了研究花种子飞行的流体动力学.
- 在种子散布过程中揭示的有效机制.
- 在生物结构中识别新的流体行为.
主要方法:
- 在花种子周围的空气流动的可视化.
- 体结构的分析,包括它的多孔性.
- 使用可控孔径的微制造磁盘复制流动行为.
主要成果:
- 发现一个由形成的独特的分离环.
- 鉴定的圆盘状几何形状和多孔度是形成的关键.
- 证明优化的多孔性稳定了,最大化了空气动力学效率.
结论:
- 这种分离的环代表了水下物体周围的新一类流体行为.
- 这种流体机制可以为运动,减重和保持颗粒的设计提供信息.
- 公的气动性能和材料效率都非常精确.
相关概念视频
Separation of Sister Chromatids
4.5K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.5K
Optimizing Chromatographic Separations
1.0K
Optimizing chromatographic separations is crucial for obtaining clean separations in a minimum amount of time. Optimization is required for several factors, including kinetic effects related to band broadening, plate height, capacity factor, and separation factor.
Band broadening refers to spreading solute bands as they travel through the column. This broadening can impact resolution. Plate height (H) represents the length required for one theoretical plate. A lower plate height corresponds to...
Band broadening refers to spreading solute bands as they travel through the column. This broadening can impact resolution. Plate height (H) represents the length required for one theoretical plate. A lower plate height corresponds to...
1.0K
Separable Differential Equations
90
A separable differential equation is a type of first-order differential equation where the derivative dy/dx can be expressed as a product of two functions: one that depends only on x and another that depends only on y. This allows for the rearrangement of the equation so that all terms involving y are on one side, and all terms involving x are on the other. This process, known as the separation of variables, simplifies the process of solving the equation by enabling the integration of both...
90
Overview Of Cell Separation And Isolation
7.6K
Cell separation was first achieved in 1964 by S. H. Seal, who separated large tumor cells from the smaller blood cells using filtration. Two years later, Pohl and Hawk performed experiments on how cells respond differently to a nonuniform electric field based on the cell type. Such observations were the inception of cell separation methods, which allow isolating a single cell type from a heterogeneous sample.
7.6K
Types of Building Separation Joints
607
Building separation joints divide large or complex building structures into smaller, discrete units that can move independently. These joints are categorized into three types: volume-change joints, settlement joints, and seismic separation joints.
Volume-change joints address the effects of expansion and contraction due to temperature and moisture variations. They are strategically placed at discontinuities in a building's mass where cracking is most likely and are spaced about 150 to 200...
Volume-change joints address the effects of expansion and contraction due to temperature and moisture variations. They are strategically placed at discontinuities in a building's mass where cracking is most likely and are spaced about 150 to 200...
607
The Sympathetic Nervous System
103.6K
Overview
103.6K


