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Dilatant
A dilatant, or shear-thickening, fluid is a material whose apparent viscosity rises under shear, as with cornstarch and water, a term rooted in Osborne Reynolds' 1885 dilatancy.
Dilatometry
Dilatometry is a thermal analysis technique that measures how a specimen's length changes with temperature, yielding thermal expansion coefficients and phase transformations in metals, glass, and ceramics.
Dilaton
The dilaton is a spin-0 scalar field, the partner of the graviton in string theory, that sets coupling strengths and is searched for as a dark matter or dark energy candidate.
Dilemma
A dilemma is a logical argument form built from two conditional statements and a disjunctive premise, so a stated conclusion follows from either alternative; in ethics it names conflicting obligations.
Dillon D. Fong
Dillon D. Fong is a condensed matter physicist and staff scientist at Argonne National Laboratory who studies oxide thin films using in situ synchrotron x-ray scattering.
Dilute magnetic semiconductor
A dilute magnetic semiconductor (DMS) is a semiconductor doped with a few atomic percent of a magnetic transition metal, such as Mn in (Ga,Mn)As, which is ferromagnetic up to 190 K.
Dilution refrigerator
A dilution refrigerator is a cryogenic device that cools to around 10 millikelvin by circulating a helium-3 and helium-4 mixture, the workhorse for superconducting quantum processors and sub-Kelvin detectors.
Dilworth's theorem
Dilworth's theorem is a 1950 result in order theory stating that a finite poset can be partitioned into chains, whose minimum number equals its largest antichain.
Dimas G. de Oteyza
Dimas G. de Oteyza is a nanoscale physicist at the Donostia International Physics Center in San Sebastián, known for graphene nanoribbon synthesis and imaging covalent bonds in single-molecule reactions.
Dimedone
Dimedone, also called methone or dimethyldihydroresorcinol, is a cyclic diketone used in organic chemistry as a classical reagent for detecting aldehydes and as a precursor for heterocycles.
Dimension
Dimension in topology is a numerical invariant, usually the Lebesgue covering dimension, counting a space's independent directions; homeomorphic spaces share it, and Euclidean space Rn has dimension n.
Dimension (vector space)
In linear algebra, the dimension of a vector space, also called its Hamel dimension, is the number of vectors in any basis of the space.
Dimension theory (algebra)
Dimension theory in commutative algebra studies the Krull dimension of a ring, the supremum of lengths of chains of prime ideals, introduced by Wolfgang Krull in 1928 and matching the geometric dimension of varieties.
Dimensional analysis
Dimensional analysis is a method in physics and engineering that uses physical dimensions like mass, length, and time to check equations, suggest relationships, and reduce variables in experiments.
Dimensional matrix
A dimensional matrix is a table whose columns are a problem's physical variables and whose rows are fundamental dimensions, central to dimensional analysis and the Buckingham pi theorem.
Dimensional regularization
Dimensional regularization is a quantum field theory technique that handles ultraviolet divergences by evaluating loop integrals in d dimensions, introduced in 1972 by 't Hooft and Veltman and others.
Dimensionless physical constant
A dimensionless physical constant is a pure number in physics, such as the fine-structure constant, whose value does not depend on the choice of units.
Dimensionless quantity
A dimensionless quantity, also called a dimensionless or unitless quantity, is a physical quantity with no units, such as the Mach number, refractive index, and plane angle.
Dimensions (research database)
Dimensions is a multidisciplinary research database and analytics platform launched by Digital Science in January 2018, linking publications and citations with grants, patents, clinical trials, and policy documents.
Dimercaprol
Dimercaprol, also known as British anti-Lewisite (BAL), is a dithiol chelating agent, 2,3-dimercapto-1-propanol, used to treat poisoning by arsenic, gold, inorganic mercury, and, with edetate calcium disodium, acute lead poisoning.
Dimethoate
Dimethoate is a systemic organophosphate insecticide and acaricide, introduced on the market in 1956 to control insects including mites, flies, aphids, and plant hoppers; it kills by inhibiting acetylcholinesterase.
Dimethoxyethane
Dimethoxyethane, formally 1,2-dimethoxyethane and commonly called monoglyme, is a colorless, water-miscible ether used as an aprotic solvent in organic synthesis and as the principal ether solvent in lithium battery electrolytes.
Dimethyl carbonate
Dimethyl carbonate, also called carbonic acid dimethyl ester, is a colorless, flammable liquid ester of carbonic acid used as a green methylating agent, solvent, and battery electrolyte co-solvent.
Dimethyl carbonate synthesis from carbon dioxide
Dimethyl carbonate synthesis from carbon dioxide converts CO₂ and methanol into dimethyl carbonate (DMC), directly or via intermediates like ethylene carbonate; low yields from water formation remain the main obstacle.
Dimethyl disulfide
Dimethyl disulfide is a colorless, oily organosulfur liquid with a garlic-like odor, the most commonly used sulfiding agent for activating petroleum refining catalysts and, under the name Paladin, a preplant soil fumigant.
Dimethyl ether
Dimethyl ether (DME, CH₃OCH₃), also called methoxymethane, is the simplest ether, a highly flammable gas used mainly as an aerosol propellant and studied as a soot-free alternative diesel fuel.
Dimethyl isosorbide
Dimethyl isosorbide (DMI) is a high-boiling dipolar aprotic solvent derived from the plant sugar sorbitol, promoted as a bio-based replacement for the reproductive-toxic solvents NMP and DMF.
Dimethyl malonate
Dimethyl malonate is the dimethyl ester of malonic acid, a colorless liquid whose acidic central methylene underlies the malonic ester synthesis used to build pharmaceuticals and fragrances.
Dimethyl methylphosphonate
Dimethyl methylphosphonate (DMMP) is a colorless, water-miscible organophosphorus compound used mainly as an additive flame retardant and as the standard simulant for nerve agents such as sarin in detector testing.
Dimethyl oxalate
Dimethyl oxalate is the dimethyl ester of oxalic acid, a crystalline solid made industrially by coupling carbon monoxide with methyl nitrite and hydrogenated to ethylene glycol.