the high spectral purity
11Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
12White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …
13rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
14Monochromator — in a x ray beamline at the Advanced Photon Source, Argonne National Laboratory. A monochromator is an optical device that transmits a mechanically selectable narrow band of wavelengths of light or other radiation chosen from a wider range of… …
15photography, technology of — Introduction equipment, techniques, and processes used in the production of photographs. The most widely used photographic process is the black and white negative–positive system (Figure 1 >). In the camera the lens projects an image of… …
16X-ray fluorescence — (XRF) is the emission of characteristic secondary (or fluorescent) X rays from a material that has been excited by bombarding with high energy X rays or gamma rays. The phenomenon is widely used for elemental analysis and chemical analysis,… …
17Synthetic diamond — Synthetic diamonds of various colors grown by the high pressure high temperature technique Synthetic diamond is diamond produced in a technological process; as opposed to natural diamond, which is created in geological processes. Synthetic… …
18Phase-locked loop — PLL redirects here. For other uses, see PLL (disambiguation). A phase locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input reference signal. It is an electronic… …
19Daoism — or Taoism Major Chinese religio philosophical tradition. Though the concept of dao was employed by all Chinese schools of thought, Daoism arose out of the promotion of dao as the social ideal. Laozi is traditionally regarded as the founder of… …
20Iron — Fe redirects here. For other uses, see Fe (disambiguation). This article is about the chemical element. For other uses, see Iron (disambiguation). manganese …
