- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A Depolarized Dynamic Light Scattering Method to Calculate Translational and Rotational Diffusion Coefficients of Nanorods
摘要： A new analysis of depolarized dynamic light scattering data is presented, which allows the unambiguous determination of rotational and translational diffusions coefficients of nanorods in suspension. By visualizing data scaling, purely translational diffusive motions can be isolated from vertically polarized scattering, allowing the unique determination of rotational diffusion from the depolarized scattering. The method is applied to nanorods with four different aspect ratios, and compared with theoretical predictions. Diffusion coefficients obtained show good agreement with calculations based on the direct measurements of rod length and diameter. Where the theories are shown to be valid, the method allows the measurement of statistically meaningful particle sizes and aspect ratios.
关键词： depolarized dynamic light scattering,gold nanorods,Brownian motion,translational diffusion,rotational diffusion
更新于2025-09-10 09:29:36
-
Tuning phototactic robots with sensorial delays
摘要： The presence of a delay between sensing and reacting to a signal can determine the long-term behavior of autonomous agents whose motion is intrinsically noisy. In a previous work [Mijalkov, McDaniel, Wehr, and Volpe, Phys. Rev. X 6, 011008 (2016)], we have shown that sensorial delay can alter the drift and the position probability distribution of an autonomous agent whose speed depends on the illumination intensity it measures. In this work, we consider an agent whose speed and rotational diffusion both depend on the illumination intensity and are subject to two independent sensorial delays. Using theory, simulations, and experiments with a phototactic robot, we study the dependence of the drift and of the probability distribution of the robot’s position on the sensorial delays. In particular, the radial drift may have a positive as well as negative sign, and the position probability density peaks in different regions, depending on the choice of the model’s parameters. This not only generalizes previous work but also explores new phenomena resulting from the interaction between the two delay variables.
关键词： autonomous agents,phototactic robot,sensorial delay,rotational diffusion,position probability distribution
更新于2025-09-10 09:29:36