42,772 articles
Johnson solid
A Johnson solid, also called a Johnson polyhedron, is one of the 92 strictly convex polyhedra with regular polygon faces that are not Platonic or Archimedean solids, prisms, or antiprisms.
Johnson-Kendall-Roberts theory
The Johnson-Kendall-Roberts theory, abbreviated JKR, is a 1971 contact mechanics model describing adhesive contact between elastic bodies by balancing elastic deformation energy against surface energy.
Johnson–Corey–Chaykovsky reaction
The Johnson–Corey–Chaykovsky reaction is an organic reaction in which a sulfur ylide transfers a methylene group, converting aldehydes and ketones to epoxides, imines to aziridines, and alkenes to cyclopropanes.
Johnson–Nyquist noise
Johnson–Nyquist noise, also called thermal noise or Johnson noise, is electrical noise generated by random thermal motion of charge carriers in any conductor, first measured in 1928.
JOIDES Resolution
The JOIDES Resolution was a riserless scientific drillship that drilled the ocean floor for core samples, serving international ocean drilling programs from 1985 until its retirement in September 2024.
Joinpoint analysis
Joinpoint analysis is a statistical method that fits segmented linear regression to time-trend data such as disease rates, identifying where the trend changes; it is widely used in cancer surveillance.
Joint Center for Quantum Information and Computer Science
The Joint Center for Quantum Information and Computer Science (QuICS) is a joint University of Maryland and NIST research center in quantum information, founded in 2014.
Joint characteristic function
The joint characteristic function of a random vector is φ(t) = E[exp(i·tᵀX)], the ordinary characteristic function extended to several arguments; it always exists and uniquely determines the joint distribution.
Joint Committee for Guides in Metrology
The Joint Committee for Guides in Metrology (JCGM) is a joint committee of eight international organizations, formed in 1997, that maintains the GUM and the International Vocabulary of Metrology.
Joint Committee of the Regional Bodies
The Joint Committee of the Regional Bodies (JCRB) is the committee of regional metrology organizations that coordinates mutual recognition of calibration and measurement certificates under the CIPM Mutual Recognition Arrangement.
Joint Entrance Examination
The Joint Entrance Examination (JEE) is India's national entrance exam for undergraduate engineering admission, with JEE (Main) for NITs and IIITs and JEE (Advanced) the sole route to the IITs.
Joint Global Ocean Flux Study
The Joint Global Ocean Flux Study (JGOFS) was an international marine research program launched in 1987 under SCOR to quantify carbon fluxes in the ocean and atmosphere.
Joint Hurricane Testbed
The Joint Hurricane Testbed was a NOAA program established in 2001 to transfer tropical cyclone research into forecast operations at the National Hurricane Center in Miami.
Joint Implementation
Joint Implementation is one of the Kyoto Protocol's flexibility mechanisms under Article 6, allowing Annex I countries to earn emission reduction units from projects hosted in other industrialized countries.
Joint Institute for Nuclear Research
The Joint Institute for Nuclear Research (JINR; Объединенный институт ядерных исследований) is an international intergovernmental research organization in Dubna, Russia, founded in 1956, known for superheavy element discoveries.
Joint probability distribution
The joint probability distribution, or joint distribution function, gives the probability law of two or more random variables together, and is the basis for marginal and conditional distributions.
Joint Quantum Institute
The Joint Quantum Institute (JQI) is a research institute for quantum physics and quantum information science, founded in 2006 by the University of Maryland and NIST at College Park.
Joint Typhoon Warning Center
The Joint Typhoon Warning Center (JTWC) is a joint U.S. Navy and Air Force command issuing tropical cyclone forecasts and warnings for the Pacific and Indian Oceans.
Jökulhlaup
Jökulhlaup, an Icelandic word now used internationally, is a glacial outburst flood caused by failure of an ice or sediment dam or by volcanic melting.
Jombolok
Jombolok, also written Jom-Bolok or Zhom-Bolok, is a Holocene basaltic volcanic field in the East Sayan Mountains of Siberia, Russia, whose youngest flows erupted around 737 CE, among Central Asia's most recent eruptions.
Jon Folkman
Jon Hal Folkman (1938–1969) was an American mathematician who earned his Ph.D. at Princeton under John Milnor and worked at RAND; his Folkman numbers and finite-sums theorem are named for him.
Jon Kosloski
Jon Kosloski is an American NSA research scientist in quantum optics and crypto-mathematics, named in August 2024 as director of the Pentagon's UAP office, AARO.
Jon M. Miller
Jon M. Miller (Jon Matthew Miller) is an American high-energy astrophysicist at the University of Michigan who studies black holes and neutron stars through X-ray spectroscopy.
Jon Magne Leinaas
Jon Magne Leinaas, born 1946 in Oslo, is a Norwegian theoretical physicist and professor at the University of Oslo whose 1977 work with Jan Myrheim first described anyons.
Jon R. Pratt
Jon R. Pratt is an American mechanical engineer who leads the Quantum Measurement Division at NIST and managed the measurement that redefined the kilogram in 2019.
Jon Sobus
Jon Sobus is an environmental health scientist at the United States Environmental Protection Agency who studies cumulative chemical exposures and received the Presidential Early Career Award for Scientists and Engineers.
Jonas C. Peters
Jonas C. Peters is an inorganic chemist and Bren Professor of Chemistry at Caltech, where he directs the Resnick Sustainability Institute and is known for iron catalysts that convert nitrogen gas to ammonia.
Jonas Kubilius
Jonas Kubilius (1921–2011) was a Lithuanian mathematician who founded probabilistic number theory, created the Kubilius model, and led Vilnius University as rector for over three decades.
Jonathan A. Ellman
Jonathan A. Ellman is a Yale chemistry professor elected to the National Academy of Sciences in 2025, known for his chiral sulfinamide reagent and catalytic C–H functionalization methods.
Jonathan A. Foley
Jonathan A. Foley is an American earth-systems scientist whose research linked climate, land use, and the global food system, and who leads the climate-solutions organization Project Drawdown.