All articles starting with B
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Bloc Québécois
Bloc Québécois (BQ), Quebec sovereigntist federal party founded 1990-1991 by Lucien Bouchard after Meech Lake; runs candidates only in Quebec, was Official Opposition with 54 seats in 1993, led since 2019 by Yves-François Blanchet.
BLOC-3 complex member HPS1
HPS1 (Hermansky-Pudlak syndrome 1 protein) forms the BLOC-3 heterodimer with HPS4, a Rab32/38 guanine nucleotide exchange factor for lysosome-related organelle biogenesis; HPS1 mutations cause the most common, pulmonary-fibrosis-prone HPS subtype.
BlocBoy JB
BlocBoy JB (James Baker, born 1996) is a Memphis rapper behind the 2017 viral "Shoot" dance and the Drake collaboration "Look Alive," a Billboard top-five hit with over a billion Spotify streams.
Bloch equations
The Bloch equations are differential equations describing how a sample's nuclear magnetization evolves in a magnetic field, combining Larmor precession with T1 and T2 relaxation.
Bloch MB.150
The Bloch MB.150 was a French all-metal fighter developed in the mid-1930s by Avions Marcel Bloch, whose production version, the MB.152, served in the Battle of France.
Bloch oscillations
Bloch oscillations are the coherent back-and-forth motion a quantum wave packet performs in a periodic potential under a constant force, first observed in 1992 in semiconductor superlattices.
Bloch points
A Bloch point is a point-like topological defect in the magnetization of a ferromagnet, a hedgehog singularity named for physicist Felix Bloch and first imaged in 3D by X-ray tomography.
Bloch sphere
The Bloch sphere is a unit sphere representing a single qubit's states as points, with pure states on the surface, mixed states inside, and unitary gates acting as rotations.
Bloch–Kato conjecture
The Bloch–Kato conjecture, now the norm residue isomorphism theorem, identifies Milnor K-theory modulo ℓ with étale cohomology; proved by Rost, Voevodsky, and Weibel.
Bloch's higher Chow group
Bloch's higher Chow groups are invariants CH^p(X, n) of algebraic varieties, defined by Spencer Bloch in 1986, recovering the classical Chow groups at n = 0.
Bloch's theorem
Bloch's theorem, proved by Felix Bloch in 1928, states that electron states in a periodic crystal potential are plane waves modulated by a lattice-periodic function, founding band theory.
Block
Block, Inc., formerly Square, Inc., is an American financial technology company founded by Jack Dorsey and Jim McKelvey in 2009, operating the Square and Cash App platforms from Oakland, California.
Block (Internet)
A block, or Internet blocking, is the deliberate prevention of network traffic or access to a resource, performed by firewalls, packet filters, and DNS filtering resolvers.
Block (periodic table)
A block of the periodic table is a set of elements grouped by which orbital type, s, p, d, or f, receives the last electron.
Block 6 (Oman)
Block 6 is Petroleum Development Oman's main onshore oil and gas concession in Oman, covering roughly a third of the country and most of its oil output.
Block A-18 (Malaysia–Thailand Joint Development Area)
Block A-18 is a natural gas production block in the Malaysia–Thailand Joint Development Area of the lower Gulf of Thailand, producing since 2005 and split equally between Thailand and Malaysia.
Block and tackle
A block and tackle, also called a block and fall, is a system of pulleys mounted in blocks and threaded with a single rope, multiplying force for lifting loads.
Block B (블락비)
Block B (블락비, short for Blockbuster) is a seven-member South Korean hip-hop boy group formed in 2011 by Cho PD, known for Zico's self-produced hits Very Good and H.E.R, the Blooming Period EP, and the Bastarz sub-unit.
Block bootstrap
The block bootstrap is a resampling method for time-series data that resamples blocks of consecutive observations to preserve autocorrelation, proposed by Hans R. Künsch in 1989.
Block cipher
A block cipher, or symmetric block cipher, is a cryptographic algorithm that encrypts fixed-length blocks of data under a secret key; AES, NIST's standard since 2001, replaced DES.
Block cipher mode of operation
A block cipher mode of operation is a method for using a block cipher such as AES to encrypt messages of any length, providing confidentiality or authentication.
Block code
A block code is an error-control method that maps fixed-length k-bit message blocks to longer n-bit codewords so a receiver can detect or correct transmission errors, with rate k/n.
Block construction (shipbuilding)
Block construction is a shipbuilding method in which a ship is divided into prefabricated structural blocks, joined on a dock or slipway to form the hull.
Block copolymer
A block copolymer is a copolymer whose molecules consist of chemically distinct blocks joined by covalent bonds, causing microphase separation into periodic nanoscale domains used in thermoplastic elastomers, membranes, drug delivery, and lithography.
Block design
A block design, also called a balanced incomplete block design, is a system of subsets of a finite point set with prescribed equal frequencies, used in statistics and combinatorics.
Block diagram
A block diagram is a diagram representing a system's functions or elements as blocks connected by lines showing signals and relationships, used in control engineering, systems engineering, and electrical practice.
Block encoding
Block encoding is a quantum algorithm technique that embeds a matrix as a block of a larger unitary, enabling non-unitary linear algebra on quantum computers.
Block floating point
Block floating point (BFP) is a number representation where a block of numbers shares a single exponent, saving storage and offering more stability than fixed point.
Block grant
A block grant is a fixed-sum transfer from a central government to state or local governments, spendable within a broad area like community development or family assistance.
Block graph
A block graph, also called a clique tree, is an undirected graph in which every block (maximal 2-connected component) is a clique, a class introduced by Frank Harary in 1963.