absorption négative
61poison — poisoner, n. poisonless, adj. poisonlessness, n. /poy zeuhn/, n. 1. a substance with an inherent property that tends to destroy life or impair health. 2. something harmful or pernicious, as to happiness or well being: the poison of slander. 3.… …
62Mathematical descriptions of opacity — When an electromagnetic wave travels through a medium in which it gets absorbed (this is called an opaque or attenuating medium), it undergoes exponential decay as described by the Beer–Lambert law. However, there are many possible ways to… …
63star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
64ion-exchange reaction — ▪ chemical reaction Introduction any of a class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions (ion)) that involves an exchange of one or more ionic components.… …
65photography, 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… …
66Nutrition — The Nutrition Facts table indicates the amounts of nutrients which experts recommend to limit or consume in adequate amounts. Nutrition (also called nourishment or aliment) is the provision, to cells and organisms, of the materials necessary (in… …
67Optics — For the book by Sir Isaac Newton, see Opticks. Optical redirects here. For the musical artist, see Optical (artist). Optics includes study of dispersion of light. Optics is the branch of …
68colour — /kul euhr/, n., adj. v.t., v.i. Chiefly Brit. color. Usage. See or1. * * * I Aspect of any object that may be described in terms of hue, brightness, and saturation. It is associated with the visible wavelengths of electromagnetic radiation, which …
69optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …
70Russia — /rush euh/, n. 1. Also called Russian Empire. Russian, Rossiya. a former empire in E Europe and N and W Asia: overthrown by the Russian Revolution 1917. Cap.: St. Petersburg (1703 1917). 2. See Union of Soviet Socialist Republics. 3. See Russian… …
