小角散射的维基解释.docxVIP

Small-angle scatteringFrom Wikipedia, the free encyclopediaSmall-angle scattering?(SAS) is a?scattering?technique based on deflection of collimated radiation away from the straight trajectory after it interacts with structures that are much larger than the wavelength of the radiation. The deflection is small (0.1-10°) hence the name?small-angle. SAS techniques can give information about the size, shape and orientation of structures in a sample.Small-angle scattering (SAS) is a powerful technique for investigating large-scale structures from 10 ? up to thousands and even several tens of thousands of angstroms. The most important feature of the SAS method is its potential for analyzing the inner structure of disordered systems, and frequently the application of this method is a unique way to obtain direct structural information on systems with random arrangement of density inhomogeneities in such large-scales.Currently, the SAS technique, with its well-developed experimental and theoretical procedures and wide range of studied objects, is a self-contained branch of the structural analysis of matter. Reflecting these situations, the international meeting on the small-angle scattering studies have been held in every three years. SAS can refer to:ApplicationsSmall-angle scattering is particularly useful because of the dramatic increase in forward scattering that occurs at phase transitions, known as?critical opalescence, and because many materials, substances and biological systems possess interesting and complex features in their structure, which match the useful length scale ranges that these techniques probe. The technique provides valuable information over a wide variety of scientific and technological applications including chemical aggregation, defects in materials,?surfactants,?colloids,?ferromagnetic?correlations in magnetism,?alloy?segregation,?polymers,?proteins, biological membranes,?viruses,?ribosome?and?macromolecules. While analysis of the data can give inf