42,772 articles
Hemocytometer
A hemocytometer, also called a counting chamber or Neubauer chamber, is a thick glass slide with an etched grid used to count cells in a known volume.
Hemodynamics
Hemodynamics is the study of the physical principles governing blood flow and blood pressure in the cardiovascular system, relating the heart's driving pressure, vascular resistance, and flow.
Hemphillian
The Hemphillian is a North American Land Mammal Age, from about 9.0 to 4.9 million years ago, defined by its mammal fauna rather than the standard geologic time scale.
Hen 1-5
Hen 1-5 is a planetary nebula in Sagitta, cataloged by Karl Henize in 1961, whose central star FG Sagittae evolved from hot nucleus to cool supergiant in a century.
Henderson molybdenum mine
The Henderson molybdenum mine is an underground block-cave mine beneath Red Mountain in Clear Creek County, Colorado, opened in 1976 and owned by Climax Molybdenum.
Henderson–Hasselbalch equation
The Henderson–Hasselbalch equation, derived by Henderson in 1908 and put in logarithmic form by Hasselbalch in 1916, calculates buffer pH from a weak acid's pKa and the base-to-acid concentration ratio.
Hendrik C. van de Hulst
Hendrik C. van de Hulst (1918–2000) was a Dutch astronomer at Leiden University who predicted the 21-centimeter hydrogen line in 1944 and wrote the classic Light Scattering by Small Particles.
Hendrik Casimir
Hendrik Casimir (1909–2000) was a Dutch theoretical physicist, trained by Ehrenfest, Bohr, and Pauli, who predicted the Casimir effect in 1948 and directed research at Philips until 1972.
Hendrik Jan Vink
Hendrik Jan Vink (1915–2009) was a Dutch solid-state physicist who spent his career at Philips NatLab in Eindhoven and, with F.A. Kröger, founded defect chemistry.
Hendrik Kloosterman
Hendrik Douwe Kloosterman (1900–1968) was a Dutch mathematician and Leiden professor known for the Kloosterman sums, introduced in his 1926 paper, and his refinement of the Hardy–Littlewood circle method.
Hendrik Lenstra
Hendrik Willem Lenstra Jr., born 1949, is a Dutch number theorist who created the LLL lattice reduction and elliptic curve factoring algorithms and taught at Berkeley and Leiden.
Hendrik Lorentz
Hendrik Lorentz, fully Hendrik Antoon Lorentz, was a Dutch theoretical physicist who refined Maxwell's electromagnetic theory, developed the electron theory, and shared the 1902 Nobel Prize in Physics.
Hendrik van der Bijl
Hendrik Johannes van der Bijl (1887–1948) was a South African physicist who gave the triode vacuum tube its mathematical basis and founded Eskom and Iscor.
Hendrika Johanna van Leeuwen
Hendrika Johanna van Leeuwen was a Dutch physicist whose 1919 Leiden thesis proved the Bohr–van Leeuwen theorem, that classical statistical mechanics gives zero magnetization; she later became the first female lector at TU Delft.
Hening Lin
Hening Lin is a chemical biologist and Howard Hughes Medical Institute investigator who joined the University of Chicago in 2024, known for establishing lysine succinylation and malonylation as regulated protein modifications.
Henize 2-10
He 2-10 (Henize 2-10) is a blue compact dwarf starburst galaxy in Pyxis, about 30 million light-years away, whose massive black hole appears to trigger star formation.
Henk Dorgelo
Hendrik Berend (Henk) Dorgelo (1894–1961) was a Dutch physicist who established the empirical intensity rules for multiplet spectral lines and, with Burger, the summation rule.
Henk J. Bolink
Henk J. Bolink (Hendrik Bolink) is a Spanish-based inorganic chemist and professor at the Universitat de València known for vacuum-deposited perovskite solar cells and LEDs.
Henning Sirringhaus
Henning Sirringhaus is a physicist who holds the Hitachi Professorship at the University of Cambridge, known for pioneering polymer transistor mobility improvements and co-founding Plastic Logic.
Hénon map
The Hénon map is a two-dimensional discrete dynamical system introduced by Michel Hénon in 1976, a standard example of chaos with a strange fractal attractor.
Henri Abraham
Henri Abraham (Henri Azariah Abraham, 1868–1943) was a French experimental physicist who directed the ENS physics laboratory, designed the T.M. triode tube, and developed the multivibrator.
Henri B. Kagan
Henri B. Kagan, born 1930 in France, is a French chemist who pioneered asymmetric catalysis and shared the 2026 Nobel Prize in Chemistry with Kenso Soai for discovering nonlinear effects.
Henri Becquerel
Antoine Henri Becquerel (1852–1908) was a French physicist who discovered natural radioactivity in 1896 and shared the 1903 Nobel Prize in Physics with Pierre and Marie Curie.
Henri Bénard
Henri Bénard (1874–1939) was a French physicist who in 1900 gave the first quantitative description of cellular convection, the hexagonal pattern now known as Bénard cells.
Henri Bouasse
Henri Bouasse (1866–1953) was a French physicist and professor at the Faculty of Sciences of Toulouse, best known for the 45-volume Bibliothèque scientifique de l'ingénieur et du physicien.
Henri Brocard
Henri Brocard (1845–1922) was a French army officer, meteorologist, and mathematician who co-founded the modern geometry of the triangle with Émile Lemoine and gave his name to the Brocard points, angle, and circle.
Henri Cartan
Henri Cartan (1904–2008) was a French mathematician, eldest son of geometer Élie Cartan and a founding member of Bourbaki, known for several complex variables, topology, and homological algebra.
Henri Delannoy
Henri-Auguste Delannoy (1833–1915) was a French army officer, trained at the École Polytechnique, who became an amateur mathematician and is remembered for the Delannoy numbers.
Henri Lebesgue
Henri Léon Lebesgue (1875–1941) was a French mathematician whose 1902 thesis founded measure theory; his integral generalizes the Riemann integral and underlies modern probability theory.
Henri Moissan
Henri Moissan (1852–1907) was a French chemist who isolated fluorine in 1886, developed the electric-arc furnace in 1892, and won the 1906 Nobel Prize in Chemistry.