42,772 articles
De novo design
De novo design, also known as de novo drug design, is a computational method that generates novel molecular structures with desired properties from scratch rather than modifying known compounds.
de Rham cohomology
De Rham cohomology assigns real vector spaces to a smooth manifold by taking closed differential forms modulo exact ones; Georges de Rham pioneered the approach in 1931.
De Sitter space
De Sitter space is the maximally symmetric solution of Einstein's equations for empty space with positive cosmological constant, a spacetime of constant positive curvature known since 1917.
de Sitter swampland conjecture
The de Sitter swampland conjecture, proposed in 2018 by Obied, Ooguri, Spodyneiko, and Vafa, states that consistent quantum gravity forbids stable or metastable de Sitter vacua.
De Sitter universe
The de Sitter universe is a 1917 cosmological model by Willem de Sitter, describing a matter-free universe with a positive cosmological constant whose expansion grows exponentially.
De-en Jiang
De-en Jiang is a computational chemist known for first-principles studies of nanomaterials, nanocatalysis, and molecular separations, who won a PECASE at Oak Ridge and now holds a chair at Vanderbilt.
Dead Sea (ים המלח)
The Dead Sea (ים המלח) is a hypersaline terminal lake in the Jordan Rift Valley between Jordan and Israel, about ten times saltier than the ocean.
Dead Sea Transform
The Dead Sea Transform, also called the Dead Sea Fault, is a roughly 1,000-km-long left-lateral fault system between the Arabian plate and the Sinai subplate.
Dead storage
Dead storage is the volume of reservoir water below the lowest outlet that cannot be drained by gravity, traditionally sized to hold decades of sediment.
Dead time
Dead time, or insensitive time, is the interval after a radiation detector records a pulse during which further ionizing events are lost, causing count loss at high rates.
Dead-weight tester
A dead-weight tester, also called a piston gauge or pressure balance, is a primary pressure standard that generates known pressure by balancing calibrated masses on a piston of known area.
Deadbeat escapement
The deadbeat escapement is a recoilless escapement for pendulum clocks, usually credited to English clockmaker George Graham around 1715, which became the standard for precision regulator clocks.
Deadweight tonnage
Deadweight tonnage (DWT) measures how much weight a ship can carry: the total mass of cargo, fuel, water, stores, crew, and passengers that brings it to its summer load line.
DEAE-cellulose
DEAE-cellulose (diethylaminoethyl cellulose) is a weakly basic anion-exchange material made by attaching diethylaminoethyl groups to cellulose; introduced in 1956, it binds and separates negatively charged molecules such as proteins, nucleic acids, and acidic polysaccharides.
deal.II
deal.II is an open-source C++ library for solving partial differential equations with adaptive finite elements, providing meshes, solvers, and scalable parallelism from laptops to supercomputers.
Deaminative alkylation
Deaminative alkylation is a set of synthetic methods in which amines replace alkyl halides as alkylating reagents, forming C–C and C–X bonds under mild conditions.
Deaminative functionalization
Deaminative functionalization is a strategy in organic synthesis in which the carbon–nitrogen bonds of abundant amines are cleaved and replaced with new carbon–carbon or carbon–heteroatom bonds, useful for late-stage functionalization.
Deaminative functionalization via Katritzky pyridinium salts
Deaminative functionalization via Katritzky pyridinium salts converts primary amines into 2,4,6-triphenylpyridinium salts whose reduction cleaves the C–N bond, releasing alkyl radicals that form new bonds.
Dean E. Eastman
Dean E. Eastman (1940–2018) was an American physicist and IBM Fellow who pioneered photoelectron spectroscopy of surfaces and directed Argonne National Laboratory from 1996 to 1998.
Dean J. Tantillo
Dean J. Tantillo (born 1973) is an American computational organic chemist and Distinguished Professor at the University of California, Davis, known for post-transition-state bifurcations in terpene biosynthesis.
Deane Montgomery
Deane Montgomery (1909–1992) was an American topologist at the Institute for Advanced Study in Princeton, best known for solving Hilbert's fifth problem with Gleason and Zippin in 1952.
DEAP-3600
DEAP-3600 (Dark matter Experiment using Argon Pulse-shape discrimination) is a liquid argon detector 2 km underground at SNOLAB in Sudbury, Canada, that searches for WIMP dark matter.
Dearomative functionalization
Dearomative functionalization is a class of organic reactions that destroys the aromaticity of an arene while installing new functionality, converting flat aromatic feedstocks into saturated three-dimensional structures.
Dearomative photoredox functionalization of pyridines
Dearomative photoredox functionalization of pyridines is a family of visible-light-driven reactions in which a photocatalyst generates radical intermediates that convert aromatic pyridines into dearomatized products under mild conditions.
Dearomatization
Dearomatization is a chemical transformation that destroys the aromatic stabilization of an arene, converting a flat aromatic ring into a nonaromatic saturated or partially saturated molecule.
Death of Colin Scott
The death of Colin Nathaniel Scott occurred in 2016, when the 23-year-old slipped into a boiling, acidic hot spring in Yellowstone National Park, and his body dissolved.
Deaths due to the Chernobyl disaster
Deaths due to the Chernobyl disaster refers to fatalities from the 1986 explosion at the Chernobyl Nuclear Power Plant in Ukraine, including both immediate and projected deaths.
Debabrata Basu
Debabrata Basu (1924–2001) was an Indian mathematical statistician, born in Dacca, whose 1955 Basu's theorem on independence of sufficient and ancillary statistics became a foundation of statistical theory.
Debabrata Maiti
Debabrata Maiti (দেবব্রত মৈতি) is an Indian chemist and Institute Chair Professor at IIT Bombay, known for distal C–H functionalization and the 2022 Bhatnagar Prize.
Deben (unit)
The deben (Egyptian dbn, meaning ring) was the standard unit of weight in ancient Egypt, equal to 91 grams in the New Kingdom, when it was divided into 10 qedet.