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2 天前 · CRISPR (/ˈkrɪspər/) (an acronym for clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea.[2] These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote. They are used to detect and ...
1 天前 · Richard Phillips Feynman ( / ˈfaɪnmən /; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, as well as his work in particle physics for which he prop...
2 天前 · Recorded 4 October 1994. Nelson Rolihlahla Mandela ( / mænˈdɛlə / man-DEH-lə; [1] Xhosa: [xolíɬaɬa mandɛ̂ːla]; born Rolihlahla Mandela; 18 July 1918 – 5 December 2013) was a South African anti-apartheid activist, politician, and statesman who served as the first president of South Africa from 1994 to 1999. He was the country's ...
1 天前 · An m × n matrix: the m rows are horizontal and the n columns are vertical. Each element of a matrix is often denoted by a variable with two subscripts.For example, a 2,1 represents the element at the second row and first column of the matrix. In mathematics, a matrix (pl.: matrices) is a rectangular array or table of numbers, symbols, or expressions, arranged in rows and columns, which is ...
3 天前 · Cynthia Ann Stephanie Lauper (/ˈlɔːpər/; born June 22, 1953) is an American singer, songwriter, actress, and activist.[2] Her career has spanned over 40 years.[3] Her album She's So Unusual (1983) was the first debut album by a female artist to achieve four top-five hits on the Billboard Hot 100—"Girls Just Want to Have Fun", "Time After ...
2 天前 · Daniel Kahneman ( / ˈkɑːnəmən /; Hebrew: דניאל כהנמן; March 5, 1934 – March 27, 2024) was an Israeli-American cognitive scientist best-known for his work on the psychology of judgment and decision-making.
2 天前 · The Northrop B-2 Spirit, also known as the Stealth Bomber, is an American heavy strategic bomber, featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. A subsonic flying wing with a crew of two, the plane was designed by Northrop (later Northrop Grumman) as the prime contractor, with Boeing, Hughes, and ...
