42,772 articles
Digital physics
Digital physics, also called computational universe theory or digital ontology, is the hypothesis that space, time, and all physical quantities are discrete and the universe is a computation.
Digital root
The digital root, also called the repeated digital sum, is the single digit left after repeatedly summing an integer's digits; it equals the remainder modulo 9.
Digital single-lens reflex camera
A digital single-lens reflex camera, or DSLR, is a digital camera whose hinged mirror and pentaprism direct light from the interchangeable lens into an optical viewfinder.
Digital soil mapping
Digital soil mapping (DSM) is a geospatial method that predicts soil properties or classes across a landscape by fitting quantitative relationships between soil observations and environmental data layers.
Digital trace data
Digital trace data are records of activity people leave when interacting with websites, social media, apps, sensors, and telecommunication networks, and are a major data source for computational social science.
Digital-analog quantum simulation
Digital-analog quantum simulation is a hybrid method combining digital quantum gates with analog evolution blocks, reproducing target system dynamics with fewer gates and less error than purely digital circuits.
Digitonin
Digitonin is a steroidal saponin glycoside extracted from the seeds of the purple foxglove, Digitalis purpurea, used in biochemistry as a membrane detergent and as a reagent that precipitates cholesterol.
Diglyme
Diglyme, also known as diethylene glycol dimethyl ether, is a colorless, water-miscible glyme solvent used in organic synthesis, coatings, semiconductor photolithography, and lithium battery electrolytes, and is classified in the EU as toxic to reproduction.
Digoxigenin
Digoxigenin is a cardenolide steroid from Digitalis foxglove plants and the aglycone of digoxin, used as a hapten for non-radioactive labeling of DNA and RNA probes.
Dihedral angle
A dihedral angle is the angle between two intersecting planes, measured on a plane normal to their shared edge; it describes faces of polyhedra and molecular torsion.
Dihedral group
The dihedral group is the group of symmetries of a regular n-sided polygon, consisting of n rotations and n reflections for 2n elements, and is a standard first example of a finite non-abelian group.
Dihedral group of order 8
The dihedral group of order 8, also called the symmetry group of a square, is the group of the eight symmetries of a square: four rotations and four reflections.
Dihomo-gamma-linolenic acid
Dihomo-gamma-linolenic acid (DGLA), also known as bishomo-gamma-linolenic acid, is a 20-carbon omega-6 fatty acid formed from gamma-linolenic acid and convertible to arachidonic acid, known as a precursor of anti-inflammatory eicosanoids such as prostaglandin E1.
Dihydrogen monoxide parody
The dihydrogen monoxide parody, also called the DHMO hoax, presents water under its chemical-sounding name with true but alarming descriptions, famously fooling officials in Aliso Viejo, California, in 2004.
Dihydropyridines
Dihydropyridines, first made by Arthur Hantzsch in 1881, are six-membered nitrogen heterocycles whose 1,4 isomer is the scaffold of calcium channel blocker drugs including nifedipine and amlodipine.
Dihydrostreptomycin
Dihydrostreptomycin is an aminoglycoside antibiotic, made by catalytic hydrogenation of streptomycin and introduced in 1946, later withdrawn from human use in the United States for ototoxicity.
Dihydrouracil
Dihydrouracil is a saturated pyrimidine, uracil with the 5,6 double bond reduced, that is the first intermediate in pyrimidine catabolism and the base of the tRNA modification dihydrouridine.
Dihydroxyacetone
Dihydroxyacetone (DHA) is the simplest ketose sugar, a three-carbon compound used almost universally in sunless tanning products, where it browns the skin through a reaction with surface amino acids.
Dihydroxylation
Dihydroxylation is the addition of two hydroxyl groups across an alkene's double bond to give a vicinal diol, done syn with osmium tetroxide or anti via epoxidation and hydrolysis.
Diimine (functional group)
Diimine, or diazene (diimide), HN=NH, is an unstable nitrogen hydride used as a reducing agent for alkenes, and by extension any compound bearing two imine (C=N) groups.
Diisobutylene
Diisobutylene (DIB) is a colorless liquid mixture of two C8 olefin isomers, produced by dimerizing isobutylene over acid catalysts and used as a chemical intermediate and fuel blending component.
Diisononyl phthalate
Diisononyl phthalate (DINP) is a mixture of branched C9 phthalate esters, used mainly as a plasticizer for polyvinyl chloride in flooring, cable, and coated products.
Diisopropyl ether
Diisopropyl ether, also known as isopropyl ether, is a highly flammable liquid ether used as an extraction solvent and gasoline additive, and it forms explosive peroxides in storage.
Diisopropyl fluorophosphate
Diisopropyl fluorophosphate, also called diisopropyl phosphorofluoridate or isoflurophate, is an organophosphorus compound synthesized in Britain in 1941 as a potential chemical warfare agent, later a glaucoma drug.
Diisopropylammonium bromide
Diisopropylammonium bromide (DIPAB) is a hydrogen-bonded molecular ferroelectric salt whose 2013 report gave it a Curie temperature of 426 K and polarization of 23 μC cm⁻², rivaling barium titanate.
Diisopropylcarbodiimide
Diisopropylcarbodiimide (DIC, also written DIPCDI) is a liquid carbodiimide coupling reagent, formula C₇H₁₄N₂, that activates carboxylic acids to form amide and peptide bonds; its soluble urea byproduct makes it preferred for solid-phase peptide synthesis.
Dike (geology)
A dike, also spelled dyke, is a sheet-like igneous intrusion that cuts across the layering of the rock it penetrates, the main path magma takes toward eruptions.
Diketene
Diketene, the dimer of ketene, is a toxic, reactive C₄H₄O₂ liquid with a strained β-lactone ring, used industrially to make acetoacetic acid derivatives for dyes, pigments, pharmaceuticals, and polymers.
Diketopyrrolopyrrole
Diketopyrrolopyrrole (DPP) is an organic pigment with a deep red color, first synthesized in the 1970s and commercialized in the 1980s for inks, paints, and plastics.
Dilatancy
Dilatancy is the volume change, dilative or compressive, induced by shear deformation of a granular material; Reynolds named it in 1885, and dense sand expands when sheared while loose sand collapses.