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quantum chromodynamics

(Encyclopedia)quantum chromodynamics (QCD), quantum field theory that describes the properties of the strong interactions between quarks and between protons and neutrons in the framework of quantum theory. Quarks p...

Leiter, Saul

(Encyclopedia)Leiter, Saul lītˈər [key], 1923–2013, American photographer, b. Pittsburgh. A painter in the early 1940s, Leiter switched to photography late in the decade. Along with Robert Frank and Diane Arbu...

buoy

(Encyclopedia)buoy boi, bo͞oˈē [key], float anchored in navigable waters to mark channels and indicate dangers to navigation (isolated rocks, mine fields, cables, and the like). The shape, color, number, and mar...

Olitski, Jules

(Encyclopedia)Olitski, Jules ŏlĭtˈskē [key], 1922–2006, American painter, b. Russia as Jevel Demikovsky. While considered a color-field painter (see color-field painting), Olitski produced works that are free...

photochemistry

(Encyclopedia)photochemistry, study of chemical processes that are accompanied by or catalyzed by the emission or absorption of visible light or ultraviolet radiation. A molecule in its ground (unexcited) state can...

Ashkin, Arthur

(Encyclopedia)Ashkin, Arthur, 1922–2020, American physicist, b. Brooklyn, N.Y., Ph.D. Cornell, 1952. Ashkin worked for four decades at Bell Laboratories, retiring in 1992. Ashkin researched microwaves, nonlinear ...

standard of living

(Encyclopedia)standard of living, level of consumption that an individual, group, or nation has achieved. The evaluation of a standard of living is relative, depending upon the judgment of the observer as to what c...

Lippman, Gabriel Jonas

(Encyclopedia)Lippman, Gabriel Jonas, 1845–1921, French physicist, Ph.D. Sorbonne, 1875. He was a professor at the Sorbonne from 1883 until his death in 1921. Lippman received the 1908 Nobel Prize in Physics for ...

bead test

(Encyclopedia)bead test, test used in the identification of certain metals. Some metallic ions that cannot be identified by a flame test are identified by a bead test. The test can also be used to confirm the resul...

Tibetan terrier

(Encyclopedia)Tibetan terrier, breed of medium-sized dog originating in Tibet probably several thousand years ago. It stands from 14 to 16 in. (35.6–40.6 cm) high at the shoulder and weighs from 15 to 30 lb (6.8�...