42,772 articles
Dirichlet process mixture model
A Dirichlet process mixture model is a Bayesian mixture model whose mixing distribution is random, allowing the number of components to be inferred from data.
Dirichlet series
A Dirichlet series is an infinite series of the form of a sum of coefficients divided by n to the power s, with s a complex variable.
Dirichlet space
The Dirichlet space is the Hilbert space of functions analytic on the open unit disk whose Dirichlet integral is finite, one of the three classical Hilbert spaces of holomorphic functions.
Dirichlet-multinomial distribution
The Dirichlet-multinomial distribution, also known as the multivariate Pólya distribution, is a probability distribution for count vectors whose category probabilities are drawn from a Dirichlet distribution.
Dirichlet's theorem on arithmetic progressions
Dirichlet's theorem on arithmetic progressions, or Dirichlet's theorem on primes, states that for coprime integers a and q, infinitely many primes satisfy p ≡ a (mod q), proved in 1837.
Dirk Bouwmeester
Dirk Bouwmeester (born 1967) is an experimental physicist in quantum optics, professor at Leiden and UC Santa Barbara, known for early quantum teleportation demonstrations and the 2014 Spinoza Prize.
Dirk Brockmann
Dirk Brockmann is a physicist and complexity scientist who works on complex networks, human mobility, and epidemic spreading, known for the effective-distance method introduced in a 2013 Science paper.
Dirk Brouwer
Dirk Brouwer (1902–1966) was a Dutch-born American celestial mechanician who spent his career at Yale University and was elected to the National Academy of Sciences in 1951.
Dirk Coster
Dirk Coster (1889–1950) was a Dutch experimental physicist who discovered hafnium with George de Hevesy in Copenhagen in 1923, then served as professor of experimental physics at Groningen from 1924 to 1949.
Dirk De Vos
Dirk De Vos, publishing as Dirk E. De Vos, is a Belgian inorganic chemist born in Mechelen in 1967, known for catalysis with zeolites and metal–organic frameworks, including shuttle catalysis.
Dirk Grundler
Dirk Grundler, born 1966, is a German physicist working on magnonics and spintronics, full professor at EPFL in Lausanne after holding a chair at TU München from 2005 to 2015.
Dirk J. Broer
Dirk J. Broer is a Dutch polymer chemist, inventor of reactive mesogens, who spent most of his career at Philips Research in Eindhoven and became a professor at TU/e.
Dirk M. Guldi
Dirk M. Guldi is a German physical chemist and Chair of Physical Chemistry I at FAU Erlangen-Nürnberg since 2004, known for charge transfer in nanocarbons and solar energy conversion.
Dirk Trauner
Dirk Trauner is an Austrian-born organic chemist known for pioneering photopharmacology, the use of synthetic light-switching molecules to control biological processes, and for total syntheses of more than 120 natural products.
Disaccharide
A disaccharide is a carbohydrate in which two monosaccharide sugars are joined by a glycosidic bond; the common ones, sharing formula C12H22O11, include sucrose, lactose, and maltose.
Disagreements on the intensity of tornadoes
Disagreements on the intensity of tornadoes, also known as tornado rating controversies, arise because tornado winds are inferred from damage, so different scales like the Fujita and TORRO systems assign different ratings.
Disc brake
A disc brake, also called a disk brake, is a friction brake in which a caliper squeezes brake pads against a rotor on the wheel hub.
Discharge (hydrology)
Discharge, also called streamflow or river discharge, is the volume of water passing a point in a channel per unit time, measured in cubic feet or meters per second.
Discharge coefficient
The discharge coefficient, also called the coefficient of discharge, is the dimensionless ratio of actual to theoretical flow rate through a restriction such as an orifice, nozzle, or Venturi tube.
Discontinuous Galerkin method
The discontinuous Galerkin (DG) method is a finite element method for numerically solving partial differential equations, using discontinuous polynomials coupled through numerical fluxes at element boundaries.
Discontinuous precipitation
Discontinuous precipitation, also called cellular precipitation, is a solid-state reaction in which a supersaturated alloy decomposes at a migrating grain boundary into lamellar phases, discovered in 1930.
Discontinuous shear thickening
Discontinuous shear thickening is the abrupt, large jump in viscosity seen in dense particle suspensions like cornstarch in water, when a critical shear stress is exceeded.
Discotic liquid crystal
A discotic liquid crystal is a liquid crystal formed by disc-shaped molecules with flat aromatic cores, first recognized in 1977, used in LCD compensation films and organic electronics.
Discoveries of exoplanets
The discoveries of exoplanets, planets orbiting stars other than the Sun, began with confirmed detections in 1992 and now total more than 6,400 confirmed worlds, found mainly by transit and radial-velocity methods.
Discovery and exploration of the Solar System
The discovery and exploration of the Solar System spans naked-eye antiquity, telescopic finds like Uranus in 1781 and Neptune in 1846, and spacecraft that have reached every planet since 1962.
Discovery of cosmic microwave background radiation
The discovery of the cosmic microwave background radiation was made by Arno Penzias and Robert Wilson at Bell Labs in Holmdel, New Jersey, in 1964–65.
Discovery of cosmic rays
The discovery of cosmic rays was Victor Hess's 1912 balloon finding that penetrating ionizing radiation reaches Earth from above, confirmed by Kolhörster and named by Millikan in the mid-1920s.
Discovery of Neptune
The discovery of Neptune was the finding of the eighth planet on 23 September 1846, when Galle and d'Arrest located it near the position Le Verrier predicted from Uranus's orbit.
Discovery of nuclear fission
The discovery of nuclear fission was the 1938–1939 finding that a uranium nucleus splits into two fragments when struck by a neutron, explained by Meitner and Frisch.
Discovery of radioactivity
The discovery of radioactivity was Henri Becquerel's 1896 finding that uranium salts spontaneously emit invisible radiation that fogs photographic plates, opening the study of nuclear physics.