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The classes of anomalous diffusions are classified as follows: α < 1: subdiffusion. This can happen due to crowding or walls. For example, a random walker in a crowded room, or in a maze, is able to move as usual for small random steps, but cannot take large random steps, creating subdiffusion.
Figure 1. Whole-cell current recordings of K ir 2 inwardly-rectifying potassium channels expressed in an HEK293 cell. (This is a strongly inwardly rectifying current. Downward deflections are inward currents, upward deflections outward currents, and the x-axis is time in seconds.)
Single-wavelength anomalous diffraction (SAD) is a technique used in X-ray crystallography that facilitates the determination of the structure of proteins or other biological macromolecules by allowing the solution of the phase problem.
Multi-wavelength anomalous diffraction (sometimes Multi-wavelength anomalous dispersion; abbreviated MAD) is a technique used in X-ray crystallography that facilitates the determination of the three-dimensional structure of biological macromolecules (e.g. DNA, drug receptors) via solution of the phase problem.
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
"Anomalous diffusion" commonly refers only to this very generic model, and not the many other possibilities that might be described as anomalous. Also, a power law is, in a strict sense, the expected form only for a narrow range of rigorously defined systems, for instance when the distribution of obstacles is fractal .
Whereas if the index increases with increasing wavelength (which is typically the case in the ultraviolet [4]), the medium is said to have anomalous dispersion. At the interface of such a material with air or vacuum (index of ~1), Snell's law predicts that light incident at an angle θ to the normal will be refracted at an angle arcsin( sin ...
The anomalous diffraction approximation offers a very approximate but computationally fast technique to calculate light scattering by particles. The ratio of refractive indices has to be close to 1, and the size parameter should be large. However, semi-empirical extensions to small size parameters and larger refractive indices are possible.