Search results
Results from the WOW.Com Content Network
Photo 51 is an X-ray based fiber diffraction image of a paracrystalline gel composed of DNA fiber [1] taken by Raymond Gosling, [2] [3] a postgraduate student working under the supervision of Maurice Wilkins and Rosalind Franklin at King's College London, while working in Sir John Randall's group.
X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering , when there is no change in the energy of the waves.
A year later, X-ray diffraction was further applied to visualize the three-dimensional structure of an unstained human chromosome. [20] X-ray microscopy has thus shown its great ability to circumvent the diffractive limit of classic light microscopes; however, further enhancement of the resolution is limited by detector pixels, optical ...
An X-ray filter (or compensating filter) is a device placed in front of an X-ray source in order to reduce the intensity of particular wavelengths from its spectrum and selectively alter the distribution of X-ray wavelengths within a given beam before reaching the image receptor. [1]
X-ray optics is the branch of optics dealing with X-rays, rather than visible light.It deals with focusing and other ways of manipulating the X-ray beams for research techniques such as X-ray diffraction, X-ray crystallography, X-ray fluorescence, small-angle X-ray scattering, X-ray microscopy, X-ray phase-contrast imaging, and X-ray astronomy.
An X-ray generator generally contains an X-ray tube to produce the X-rays. Possibly, radioisotopes can also be used to generate X-rays. [1]An X-ray tube is a simple vacuum tube that contains a cathode, which directs a stream of electrons into a vacuum, and an anode, which collects the electrons and is made of tungsten to evacuate the heat generated by the collision.
Crick, however, knowing the Fourier transforms of Bessel functions that represent the X-ray diffraction patterns of helical structures of atoms, correctly interpreted further one of Franklin's experimental findings as indicating that DNA was most likely to be a double helix with the two polynucleotide chains running in opposite directions ...
X-ray diffraction topography is one variant of X-ray imaging, making use of diffraction contrast rather than absorption contrast which is usually used in radiography and computed tomography (CT). Topography is exploited to a lesser extent with neutrons , and is the same concept as dark field imaging in an electron microscope .