42,772 articles
Phloroglucinol
Phloroglucinol (benzene-1,3,5-triol) is an organic compound with three hydroxy groups on alternating carbons of a benzene ring, a parent of many natural products, and a musculotropic antispasmodic sold as Spasfon.
Phobos (Φόβος) (moon)
Phobos is the larger and innermost of Mars's two moons, an irregular, dark body discovered in 1877 that orbits closer to its planet than any other moon.
Phoebus Levene
Phoebus Levene (born Fishel Aaronovich Levin) was a Russian-born American biochemist who spent his career at the Rockefeller Institute studying nucleic acids, identifying ribose and deoxyribose and proposing the tetranucleotide hypothesis.
Phoenix Cluster
The Phoenix Cluster, also known as the Phoenix galaxy cluster, is a massive galaxy cluster about 5.8 billion light-years from Earth whose central galaxy forms stars at hundreds of solar masses per year.
Phon
The phon is a psychoacoustic unit of loudness level: the sound pressure level in decibels of a 1,000-Hz tone that listeners judge equally loud to a given sound.
Phonetica
Phonetica (ISSN 0031-8388) is a peer-reviewed phonetic science journal founded in 1957 by Eberhard Zwirner, published by Karger until 2020 and by De Gruyter Mouton since 2021, now open access with editors Benjamin Tucker and Richard Wright.
Phonon
A phonon is a quantum of vibrational energy in a crystal lattice, a quasiparticle that is the main vehicle through which solids store and conduct heat.
Phonon bottleneck
A phonon bottleneck is a slowdown of hot-carrier relaxation in semiconductors, caused when energy gaps fail to match available phonon energies, relevant to hot-carrier solar cells.
Phonon density of states
The phonon density of states, also called the vibrational density of states, counts the vibrational modes of a crystal per frequency interval and determines heat capacity, entropy, and free energy.
Phonon drag
Phonon drag is a solid-state transport effect in which phonons carrying heat transfer momentum to charge carriers, adding an extra contribution to the thermoelectric power, described theoretically by Conyers Herring in 1954.
Phonon engineering
Phonon engineering is the deliberate design of a material's structure, composition, or interfaces to control phonons, the quasiparticles of crystal-lattice vibration that carry heat, enabling thermoelectrics and device cooling.
Phonon hydrodynamics
Phonon hydrodynamics is a regime of heat transport in crystals in which phonons move collectively like a fluid, producing second sound, Poiseuille flow, and thermal vortices instead of ordinary diffusion.
Phonon magnetic moment
The phonon magnetic moment is a magnetic moment carried by a circularly polarized crystal vibration, or chiral phonon, detectable as Zeeman splitting in a magnetic field.
Phonon mean free path
The phonon mean free path (MFP) is the average distance a phonon, the quantum of lattice vibration, travels between scattering events, spanning nanometers to millimeters within one material.
Phonon polariton
A phonon polariton is a quasiparticle formed by strong coupling between infrared photons and polar optical phonons in crystals like silicon carbide and boron nitride, first predicted in 1951.
Phonon polariton canalization
Canalization of hyperbolic phonon polaritons is a propagation regime in which polaritons in anisotropic crystals travel as highly collimated, diffraction-free beams with a nearly fixed group velocity direction.
Phonon thermal Hall effect
The phonon thermal Hall effect is a magnetic-field-induced transverse heat current carried by phonons, first observed in 2005 in terbium gallium garnet; its mechanism remains debated.
Phonon-glass electron-crystal
Phonon-glass electron-crystal (PGEC) is a design concept for thermoelectric materials, introduced by Glen A. Slack in 1995, calling for solids that conduct heat poorly but electricity well.
Phonon-liquid electron-crystal in copper selenide
The phonon-liquid electron-crystal (PLEC) concept describes copper selenide, where a rigid selenium sublattice conducts charge while liquid-like copper ions suppress heat transport, proposed in 2012.
PhononDB
PhononDB is an open database of first-principles phonon calculations covering roughly 10,000 inorganic crystals, created by Atsushi Togo and Isao Tanaka at Kyoto University using VASP and phonopy.
Phononic crystal
A phononic crystal is an artificial, periodically structured material that controls sound and elastic waves through acoustic band gaps, a concept developed since the 1990s by analogy to photonic crystals.
Phorbol
Phorbol is a tetracyclic diterpenoid alcohol, first characterized from croton oil in 1930, whose esters are potent protein kinase C activators and classic tumor-promoting research tools.
Phorbol 12-myristate 13-acetate
Phorbol 12-myristate 13-acetate (PMA), also called TPA, is a potent phorbol ester from croton oil that mimics diacylglycerol and is widely used to activate protein kinase C in cells.
Phosgene
Phosgene, also known as carbonyl chloride, is a colorless, highly toxic gas produced on a large industrial scale, chiefly for polyurethane manufacture, and once used in chemical warfare.
Phoslock
Phoslock is a lanthanum-modified bentonite clay, about 95% bentonite and 5% lanthanum, that binds phosphorus in lakes and reservoirs to control eutrophication and cyanobacterial blooms.
Phosmet
Phosmet is a non-systemic organophosphate insecticide and acaricide that kills insects by contact and ingestion through inhibition of acetylcholinesterase, used mainly on fruit crops and first registered in the United States in 1966.
Phosphaalkyne
A phosphaalkyne is an organophosphorus compound of the general formula R–C≡P, containing a phosphorus–carbon triple bond; the parent compound, phosphaethyne, was synthesized in 1961.
Phosphate
Phosphate is any salt or ester of the tetrahedral phosphate ion PO₄³⁻, the form in which nearly all natural phosphorus occurs and a nutrient essential to DNA, cellular energy, and cell membranes.
Phosphate minerals
Phosphate minerals are naturally occurring crystalline compounds built around the phosphate anion, forming a major mineral class dominated by apatite and supplying nearly all phosphorus used in fertilizers.
Phosphate rock
Phosphate rock is a natural rock containing apatite, a calcium phosphate mineral mined as the primary source of phosphorus for phosphate fertilizers vital to agriculture.