42,772 articles
Dudley's theorem
Dudley's theorem, also called the Dudley entropy integral bound, bounds the expected supremum of a sub-Gaussian process by an integral of the metric entropy of its index set.
Duffin–Schaeffer conjecture
The Duffin–Schaeffer conjecture, posed by R. J. Duffin and A. C. Schaeffer in 1941, gave a criterion for when almost every real number is approximated infinitely often by reduced fractions.
Duffing equation
The Duffing equation is a nonlinear second-order differential equation modeling an oscillator with a cubic restoring force, published by Georg Duffing in 1918 and a classical example of chaos.
Dugald River mine
The Dugald River mine is an underground zinc, lead, and silver mine about 65 km north-west of Cloncurry, Queensland, wholly owned by MMG Limited and ranked among the world's top 10 zinc mines.
Duhem–Quine thesis
The Duhem–Quine thesis is the philosophy of science claim that hypotheses are tested only as part of a bundle of auxiliary assumptions, named for Pierre Duhem and Willard Van Orman Quine.
Duilio Arigoni
Duilio Arigoni (1928–2020) was a Swiss organic chemist and professor at ETH Zurich, known for work on natural-product biosynthesis and the stereochemistry of enzymatic reactions.
Dulbecco's Modified Eagle Medium
Dulbecco's Modified Eagle Medium, known as DMEM, is a cell culture medium described by Renato Dulbecco in 1959 and now widely used for mammalian cell culture.
Dummy variable (statistics)
A dummy variable, also called an indicator variable, is a binary variable that takes the value 1 or 0 to include categorical data in regression models.
Dunam
The dunam, from Ottoman dönüm and also spelled dunum, is a Middle Eastern land unit of 1,000 square meters, still used in Israel, Palestine, Jordan, Lebanon, and Syria.
Duncan A. MacInnes
Duncan A. MacInnes (1885–1965) was an American electrochemist at the Rockefeller Institute for Medical Research, known for the glass electrode for pH measurement, the moving-boundary method for transference numbers, and experimental confirmation of the Debye-Hückel theory.
Duncan Ross Lorimer
Duncan Ross Lorimer is a West Virginia University astronomer best known for co-discovering the first fast radio burst, the Lorimer Burst, and sharing the 2023 Shaw Prize in Astronomy.
Duncan Sommerville
Duncan Sommerville, fully Duncan McLaren Young Sommerville (1879–1934), was a mathematician who worked on non-Euclidean and higher-dimensional geometry, first at St Andrews and from 1915 as professor at Victoria College, Wellington, New Zealand.
Dune
A dune, also called a sand dune, is a mound or ridge of wind-blown sand with a steep slipface, formed mainly in deserts and along sandy coasts.
Dung-Hai Lee
Dung-Hai Lee is a theoretical condensed matter physicist and professor of physics at UC Berkeley since 1994, known for work on high-temperature superconductors and topological phases of matter.
Dunham Jackson
Dunham Jackson (1888–1946) was an American mathematician who founded quantitative approximation theory, proved Jackson's inequality, and was professor of mathematics at the University of Minnesota from 1919 until his death.
Dunhuang Star Chart
The Dunhuang Star Chart (Dunhuang xingtu, 敦煌星图) is a Chinese star atlas of the Tang dynasty, the oldest complete star atlas known, held in the British Library.
Dunite
Dunite is a coarse-grained ultramafic igneous rock of more than 90 percent olivine, named by Ferdinand von Hochstetter in 1859 after New Zealand's Dun Mountain.
Dunwei Wang
Dunwei Wang is a chemist at Boston College whose research stores solar energy in chemical fuels, chiefly through photoelectrochemical water splitting, and he has led a laboratory there since 2007.
Duodecimal
Duodecimal, also called dozenal or base twelve, is a positional numeral system using twelve digits. Its base twelve divides evenly by 2, 3, 4, and 6, so fractions like 1/3 terminate.
Duplex (geology)
In structural geology, a duplex is an array of thrust faults splaying up from a floor thrust and recombining onto a roof thrust, stacking slices called horses.
DuPont Experimental Station
The DuPont Experimental Station, founded in 1903, is DuPont's principal research and development campus in Wilmington, Delaware, and the birthplace of nylon, Kevlar, and Tyvek.
Durango Volcanic Field
Durango Volcanic Field (Campo Volcánico de Durango), a Pliocene-Quaternary monogenetic basaltic field of ~100 cinder cones and maars covering 2,100 km2 northeast of Durango city, Mexico, with the young La Breña-El Jagüey maar complex and mantle xenolith localities.
Durban Platform
The Durban Platform for Enhanced Action is a UNFCCC decision adopted at COP 17 in Durban, South Africa, in December 2011, launching negotiations that produced the Paris Agreement.
Duricrust
Duricrust is a hard, near-surface crust formed by low-temperature weathering that cements minerals in soil, sediment, or bedrock, shaping landscapes especially in arid and tropical regions.
Đuro Kurepa
Đuro Kurepa (1907–1993) was a Yugoslav mathematician whose 1935 Paris dissertation gave the first systematic study of trees in set theory, and whose name survives in the Kurepa hypothesis and left factorial conjecture.
Dusa McDuff
Dusa McDuff, born in London in 1945, is a British mathematician who helped establish symplectic geometry as a core field and teaches at Barnard College, Columbia University.
Dusk
Dusk is the darker part of evening twilight, after sunset. In technical use it has three stages, civil, nautical, and astronomical dusk, defined by the Sun's depth below the horizon.
Dust
Dust, also known as beggar's velvet, is mineral particulate matter lifted from dry land surfaces by wind and carried in the air, reducing visibility and degrading air quality.
Dust Bowl
The Dust Bowl, also called the Dirty Thirties, was a 1930s period of drought and dust storms on the Great Plains that drove farming families to migrate.
Dust devil
A dust devil is a small, rapidly rotating whirlwind made visible by dust, formed by surface heating on hot, dry afternoons rather than by a storm cloud.