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nucleus 音标拼音: [n'ukliəs] n. 核心,核子,原子核,中坚 核心,核子,原子核,中坚 nucleus 核( 心 ); 核心; 核心程序; 核 nucleus 核心 nucleus n 1: a part of the cell containing DNA and RNA and responsible for growth and reproduction [synonym: {nucleus}, {cell nucleus}, {karyon}] 2: the positively charged dense center of an atom 3: a small group of indispensable persons or things; "five periodicals make up the core of their publishing program" [synonym: {core}, {nucleus}, {core group}] 4: (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail 5: any histologically identifiable mass of neural cell bodies in the brain or spinal cord 6: the central structure of the lens that is surrounded by the cortex [synonym: {lens nucleus}, {nucleus}] Nucleus \Nu"cle*us\, n.; pl. E. {Nucleuses}, L. {Nuclei}. [L., a kernel, dim. fr. nux, nucis, nut. Cf. {Newel} post.] [1913 Webster] 1. A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively. [1913 Webster] It must contain within itself a nucleus of truth. --I. Taylor. [1913 Webster] 2. (Astron.) The body or the head of a comet. [1913 Webster] 3. (Bot.) (a) An incipient ovule of soft cellular tissue. (b) A whole seed, as contained within the seed coats. [1913 Webster] 4. (Biol.) A body, usually spheroidal, in a eukaryotic cell, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents, which contains the chromosomal genetic material, including the chromosomal DNA. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see {Nucleoplasm}). See {Cell division}, under {Division}. [1913 Webster PJC] Note: The nucleus is sometimes termed the endoplast or endoblast, and in the protozoa is supposed to be concerned in the female part of the reproductive process. See {Karyokinesis}. [1913 Webster] 5. (Zool.) (a) The tip, or earliest part, of a univalve or bivalve shell. (b) The central part around which additional growths are added, as of an operculum. (c) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks. [1913 Webster] 112 Moby Thesaurus words for "nucleus":
Anlage, Kern, NMR, alpha particle, antibaryon, antilepton, antimeson, atomic nucleus, atomic particle, axiom, axis, baryon, basichromatin, beta particle, bud, center, center of action, center of gravity, centroid, centrum, chromatin, chromatin strands, core, dead center, diameter, diaphragm, egg, electron, elementary particle, elixir, embryo, epicenter, equator, essence, essential, flower, focus, fundamental, germ, germen, gist, gravamen, heart, heterochromatin, hub, hypostasis, inner essence, interior, karyosome, karyotin, kernel, lepton, loins, macronucleus, marrow, mean, meat, median, medulla, meganucleus, meson, metacenter, micronucleus, middle, midmost, midriff, midst, nave, navel, neutron, nub, nuclear force, nuclear magnetic resonance, nuclear particle, nuclear resonance, nucleolus, nucleon, nucleosynthesis, nuts and bolts, omphalos, ovum, photon, pith, pivot, plasmosome, postulate, principle, proton, quid, quiddity, quintessence, rudiment, sap, seed, soul, spark, spermatozoon, spirit, storm center, strangeness, strong interaction, stuff, substance, the nitty-gritty, thick, thick of things, triton, umbilicus, valence electron, waist, waistline, zone
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