nucleusn.

Brit.

/ˈnjuːklɪəs/, U.S.

/ˈn(j)ukliəs/

Inflections: Plural nuclei Brit.

/ˈnjuːklɪʌɪ/, U.S.

/ˈn(j)ukliˌaɪ/, (rare) nucleuses.

Origin: A borrowing from Latin. Etymon: Latin nucleus.

Etymology: < classical Latin nucleus (also nuculeus ) kernel, inner part, in post-classical Latin also core of a comet (1668 J. Hevelius Cometographia), central idea (1672), concentric layer within the earth (1702) < nuci- , nux nut (see nut n.¹) + -leus , suffix forming diminutives. Compare Spanish núcleo (1490 in sense 4a), Italian nucleo (a1674), French nucléus (1845), Portuguese núcleo (1858).

I. In scientific and other technical uses.

1. Astronomy.

a. Originally: a bright core forming the main part of the visible head of a comet or (occasionally) a meteor. Now: spec. the solid central core of a comet, composed of ice and dust.

ΘΚΠ

the world > the universe > constellation > comet or meteor > comet > [noun] > head > nucleus

nucleus1668

1668 Philos. Trans. (Royal Soc.) 3 807 Comets may more or less deviate from that streightness, both in appearance, and really;..the latter [arising] from the matter of their Bodies and Nucleus's (as he [sc. J. Hevelius] calls the substance of their Head) not increasing nor decreasing uniformly on all sides.

1678 R. Hooke Lect. & Coll. 3 The Comet, the middle of which appeared brighter than any other part;..and seemed to issue from the Nucleus or Star in the middle of the head.

1708 W. Whiston New Theory of Earth (ed. 2) ii. 76 The lowest part next the Nucleus, or Dense Body seems to be Opake.

1726 J. Swift Gulliver II. iii. ii. 30 If the Earth should pass at the Distance of one hundred thousand Miles from the Nucleus or main Body of the Comet, it must in its Passage be set on fire, and reduced to Ashes.

1784 Philos. Trans. (Royal Soc.) 74 458 It [sc. a meteor] became extinct in the S.S.E. a few sparks of the tail, nearest the nucleus, scattering themselves much in the same manner as those of a sky-rocket when burnt out.

1837 J. F. Cooper Recoll. Europe II. v. 99 The astronomers tell us that some of these comets have no visible nucleuses.

1868 J. N. Lockyer Elem. Lessons Astron. §291 The brighter part of the comet is called the head, or coma, and sometimes the head contains a brighter portion still, called the nucleus.

1887 Cent. Mag. Jan. 348/2 If we agree that meteorites were once part of a comet, say that it now seems probable that the nucleus is a hard, stone-like mass, or collection of such masses, which comes from ‘space’.

1929 Science 9 Aug. 133/1 N. T. Bobrovnikoff explained that the repulsive forces near the nucleus of Halley's comet are two to six times the gravitational force of the sun.

1950 Astrophysical Jrnl. 111 376 I propose to investigate the possibility that the molecules responsible for most of the light of comets near perihelion arise primarily from gases long frozen in the nuclei of comets.

1995 Astron. Now Dec. 4 New pictures from NASA's Hubble Space Telescope of the recently discovered comet Hale-Bopp show..a ‘Blob’ of free-flying debris near the comet's nucleus.

b. The darker central part of a sunspot. Now rare.Now usually called umbra: see umbra n.¹ 4b.

ΚΠ

1684 J. Flamsteed in Philos. Trans. (Royal Soc.) 14 536 When the Spot was near the middle of the Sun it appeared very broad and almost square, the Nucleus of the same Figure about 40″ diameter.

1712 Philos. Trans. 1710–12 (Royal Soc.) 27 275 Another thing that may be accounted for..is the Nuclei, or darker part of the Spots; generally in most Spots, and towards the middle of them.

1774 Philos. Trans. (Royal Soc.) 64 6 It was pleasant to see the nucleus of the spot, and the shady zone or umbra which surrounded it, so very distinct.

1871 R. A. Proctor Sun iv. 167 Spots such as the one observed by Cassini seldom exhibit the peculiarity in question [sc. the Wilson effect] in a manner which would enable the observer to theorise safely respecting the level at which nucleus, penumbra, and photosphere actually lie.

1884 Science 26 Dec. 564/1 According to the observations of Professor Langley, the black nucleus or umbra of a spot emits only about fifty-four per cent as much heat as an equal area of the normal surface.

1905 Proc. Royal Soc. 1904–5 74 54 The temperature of the Arcturian absorbing atmosphere is about the same as that of the sunspot nuclei.

1977 Jrnl. Royal Statist. Soc. A. 140 454 This change was due to an alteration in the method of counting sunspot nuclei.

c. A denser, usually brighter, central part of a galaxy or nebula.

ΘΚΠ

the world > the universe > constellation > galaxy > [noun] > nucleus

nucleus1784

the world > the universe > constellation > nebula > [noun] > nucleus

nucleus1784

1784 W. Herschel in Philos. Trans. (Royal Soc.) 74 443 I have seen double and treble nebulæ, variously arranged; large ones with small, seeming attendants;..others of the cometic shape, with a seeming nucleus in the center.

1811 W. Herschel Philos. Trans. (Royal Soc.) 101 307 In the following eighteen nebulæ we may see a still more advanced compression of it, amounting almost to the appearance of a nucleus.

1849 J. F. W. Herschel Outl. Astron. xvii. 601 The nebula in Andromeda..is visible to the naked eye... Mr. G. P. Bond, assistant at the observatory of Cambridge, U.S., describes and figures it as..very suddenly condensed at the nucleus almost to the semblance of a star.

1898 A. M. Clerke et al. Conc. Knowl. Astron. iv. vi. 534 The photograph shows both nuclei of the nebula to be stellar.

1955 Sci. Amer. May 48/3 Because of heavy dust clouds this nucleus [of the Milky Way] has not been observed visually or photographically; it was discovered by radio astronomy.

1970 Sci. Jrnl. Feb. 61/1 The emission line spectrum of a Seyfert nucleus is rather like that from typical hot clouds of gas such as the Orion Nebula.

1992 S. P. Maran Astron. & Astrophysics Encycl. 261/2 The nucleus of a galaxy is not a precisely defined entity or distinct subcomponent.

2. The core or central part of the earth or other planet (variously conceived according to the scientific thought of the time). Hence (formerly): (in some theories) †each of a supposed series of concentric layers within the earth (obsolete). Now rare in technical use.

ΘΚΠ

the world > the earth > structure of the earth > [noun] > crust > supposed interior crust

nucleus1693

1693 E. Halley in Philos. Trans. (Royal Soc.) 16 568 The External Parts of the Globe may well be reckoned as the Shell, and the internal as a Nucleus or inner Globe included within ours, with a fluid medium between... If the Internal Nucleus be likewise a Magnet, having its Poles in two other places distant also from the Axis..; we may than give a reasonable account..of the changes of the Needles Variations.

1715 tr. D. Gregory Elements Astron. I. i. §69. 144 He [sc. Kepler] found it necessary to suppose an interior Crust (which might be like a Nucleus, in regard of the exterior).

1715 tr. D. Gregory Elements Astron. I. i. §69. 145 And within this Nucleus, or rather Crust, he is forced to suppose again another interior Nucleus.

1741 Mem. Martinus Scriblerus 68 in A. Pope Wks. II A Proposal..to pierce the first crust or Nucleus of this our Earth, quite through, to the next concentrical Sphere.

a1802 E. Darwin Temple of Nature (1803) iv. 164 (note) It seems clearly to appear, that the nucleus of the globe beneath the ocean consisted of granite.

1828 H. Davy in Philos. Trans. (Royal Soc.) 118 250 The hypothesis of the nucleus of the globe being composed of fluid matter, offers a still more simple solution of the phænomena of volcanic fires.

1851 Abstr. Papers Royal Soc. 1843–50 5 807 His object here is to discover..the effects of the reaction of the fluid nucleus..upon the solid crust.

1929 Science 20 Dec. 589/1 The great deformations in the earth's crust have been caused by a cooling of the interior of the earth and the collapse of the crust to fit the reduced area of the surface of the nucleus.

1957 A. Synge tr. A. I. Oparin Origin Life on Earth iv. 125 In the centre of the Earth..there is a nucleus which is far denser than the superficial formations.

1984 D. Keane Universe & Other Poems 33 Jupiter..resembles the sun more than the earth, a massive drop of liquid hydrogen about an iron nucleus.

a. The centre or core of a material object; esp. a central part or thing around which other parts or things are grouped or collected; the centre or kernel of an aggregate or concretion.Now usually in any of various technical applications, as (Anatomy) the interior part of the lens of the eye, or of an intervertebral disc (cf. nucleus pulposus n.), (Geology) the central portion of a section of continental crust, etc.

ΘΚΠ

the world > space > relative position > central condition or position > [noun] > central part > central or innermost part

hearteOE

yolk1340

centruma1398

marrow1434

core1614

kernela1642

centrals1649

nucleus1702

centrepiece1739

1702 Philos. Trans. (Royal Soc.) 23 1284 These Balls seem to be form'd something after the manner of Bezoars, which generally have some seed for their Center or nucleus, on which Coats of another substance are gathered.

1744 Philos. Trans. 1740–41 (Royal Soc.) 41 460 In the 15th [section], he refutes..Huygen's Manner of accounting for Haloes, which is by a vast Number of very small Vapours, each with a snowy Nucleus, coated round with a transparent covering.

1793 M. Baillie Morbid Anat. xiv. 202 Some extraneous body, which becomes the nucleus of the calculus.

1819 S. Cooper First Lines Pract. Surg. (ed. 4) I. ii. vii. 85 Every portion of the gangrenous cellular membrane, or nucleus extracted.

1837 Abstr. Papers Royal Soc. 1830–37 3 340 There is, at first sight, a considerable resemblance between the nucleus of the vesicle of De Graaf and the immature yelk of the egg of a bird.

1877 T. H. Huxley Man. Anat. Invertebrated Animals x. 619 The relatively small alimentary and reproductive viscera are sometimes aggregated into a mass, the so-called nucleus, at the posterior end of the hæmal side of the body.

1939 Sci. Monthly Nov. 451 In central Asia the east-west trends are seen to be composed of arcs which frame the nuclei of ancient rocks.

1942 D. G. Cogen in A. Pirie Lens Metabolism 293 The morphological difference between the cortex, constituting the outer layers of the lens substance, and the nucleus, constituting the inner portion, is the difference in integrity of lens fibres.

1987 S. Sandler Osteopathy ii. 24 Sometimes the trauma is very great and the annulus actually ruptures or splits completely. Then a piece of the soft nucleus is squeezed out of the disc in the way that toothpaste is squeezed out of a tube.

†b. Mineralogy. The most simple or basic form to which a crystal may be reduced by successive cleavage, corresponding to the fundamental form of the system in which it crystallizes. Obsolete.

ΚΠ

1798 Philos. Trans. (Royal Soc.) 88 429 The regular hexaedral prism of these crystals, cannot..be considered as the form of the nucleus of the crystal; and consequently is not the primitive form of the crystals of this substance.

1816 R. Jameson Treat. External Characters Minerals (ed. 2) 131 We obtain a regular figure, whose contour is very different from that which the crystal first exhibited, and which may now be further subdivided in the direction of its planes, without undergoing any further change of form. This new regular form is by Hauy named the Primitive nucleus; and the crystal whose form is the same, the Primitive form.

1855 J. D. Dana Man. Mineral. (ed. 7) ii. 23 They..have the same nucleus or fundamental form.

c. Chemistry. A particle in a fluid on which a crystal, droplet, or bubble can form; (originally) a particle that initiates nucleation, a nucleant; (in later technical use) a small crystal, droplet, or bubble formed spontaneously in a homogeneous metastable phase which is large enough to be stable and continue to grow. Also, in extended use (Materials Science): a flaw by which a crack in a crystalline or other solid material can be initiated.

ΘΚΠ

the world > matter > chemistry > crystallography (general) > crystal (general) > crystals (other miscellaneous) > [noun] > a particle on which crystals, droplets or bubbles can form

nucleus1815

1815 H. Davy in Philos. Trans. (Royal Soc.) 105 111 Amongst the substances found in the baths of Titus were some masses of a grass green colour... They proved..to be carbonate of copper, but it had formed round longitudinal nuclei of red oxide of copper.

1857 W. A. Miller Elements Chem.: Org. (1862) ii. §1. 90 Small pieces of wood are then introduced to act as nuclei upon which the crystals of lactose are deposited.

1886 Proc. Royal Soc. Edinb. 13 79 If this were the case, no nucleus would be absolutely requisite for the formation either of liquid from vapour or of vapour from liquid.

1922 T. M. Lowry Inorg. Chem. xxix. 494 The local deposition of amorphous silica around nuclei of organic matter in beds of chalk.

1952 Industr. & Engin. Chem. June 1273/1 A nucleus in water-fog formation consists of about 80 water molecules.

1967 A. H. Cottrell Introd. Metall. xii. 154 When the probability of forming a nucleus is the same everywhere, the system is in a state suitable for homogeneous nucleation.

1989 A. C. Davies Sci. & Pract. Welding (ed. 9) I. ii. 150 Faults in a weld such as slag inclusion..may serve as nuclei for a crack from which the brittle fracture may be projected.

1990 C. Pellant Rocks, Minerals & Fossils 45/3 The ooliths are small.., rounded or sub-rounded grains made of concentric layers of calcite precipitated around a nucleus.

4. Botany.

†a. The innermost, often edible portion of a nut. Obsolete.

ΘΚΠ

the world > plants > part of plant > reproductive part(s) > fruit or reproductive product > nut > [noun] > kernel

nut kerneleOE

kernelc1000

gristle?1537

kern1570

nucleus1704

nut-meat1860

1704 J. Harris Lexicon Technicum I Nucleus is the Edible part of the Kernel of any Nut, which is contained within the Skin of the Kernel.

1738 E. Chambers Cycl. (ed. 2) at Nut A hard cortex, or shell; which contains a softer edible nucleus, or kernel.

1785 T. Martyn tr. J.-J. Rousseau Lett. Elements Bot. xxviii. 439 The fruit is a drupe containing a nut, with a furrowed shell, within which is a four-lobed, irregularly furrowed nucleus.

1845 A. Wood Class-bk. Bot. ii. 338 J. cinerea..nucleus oblong, acuminate, deeply and irregularly furrowed.

†b. The part of a seed enclosed by integuments. Obsolete.

ΘΚΠ

the world > plants > part of plant > reproductive part(s) > seed > [noun] > parts of > body within covering

nucleus1704

kernel1796

1704 J. Harris Lexicon Technicum I Nucleus..in a larger sense is by Botanists used for any Fruit or Seed contained within an Husk or Shell.

1745 Philos. Trans. 1744–5 (Royal Soc.) 43 186 The second Specimen is that of the Angelica... When [t]he Husk is pull'd off, the Nucleus appears of a brownish Colour, and its Shape is elliptical.

1829 P. Clinton tr. A. Richard New Elem. Bot. (ed. 4) 387 The kernel or nucleus is the whole of the ripe and perfect seed contained in the cavity of the episperm.

1861 R. Bentley Man. Bot. i. iv. 343 The nucleus of the seed may either consist of the embryo alone..or of the embryo enclosed in albumen or perisperm.

1877 Philos. Trans. (Royal Soc.) 167 244 Towards the lower part of the seed we only see traces of one membrane..investing the nucleus.

1908 B. L. Robinson & M. L. Fernald Gray's New Man. Bot. (ed. 7) 880/2 Nucleus, the kernel of a seed.]

c. The nucellus of an ovule. Now disused.

ΘΚΠ

the world > life > biology > biological processes > procreation or reproduction > reproductive substances or cells > [noun] > ovum or ootid > nucleus

nucleus1827

Purkinje's vesicle1836

1827 R. Brown Char. & Descr. Kingia in P. P. King Narr. Surv. Intertropical Coasts Austral. II. App. 540 I had ascertained that in Phænogamous plants the unimpregnated Ovulum very generally consisted of two concentric membranes or coats, enclosing a Nucleus of a pulpy cellular texture.

1829 P. Clinton tr. A. Richard New Elem. Bot. (ed. 4) 383 The nucleus contained within both the integuments of the ovule is a cellular body.

1832 J. Lindley Introd. Bot. i. ii. 155 The central part is a fleshy, pointed, pulpy mass, called the nucleus or nucelle.

1861 R. Bentley Man. Bot. ii. iv. 330 As development proceeds a cavity is formed at or near the apex of the nucleus..in which the embryo..is developed.

1904 F. W. Oliver et al. tr. A. Kerner von Marilaun Nat. Hist. Plants (ed. 2) I. 644 In them [sc. the ovules] may be distinguished the nucellus (nucleus), surrounded by two, or less frequently only one coat (integumentum).

d. In lichens: the disc of an apothecium. Now rare.

ΚΠ

1832 J. Lindley Introd. Bot. i. iii. 206 Nucleus, is the disk of the shield which contains the sporules and their cases. Asci, are tubes, in which the sporules are contained while in the nucleus.

1882 Encycl. Brit. XIV. 554/2 When the pyrenium quite covers the nucleus it is said to be entire.

1885 Cassell's Encycl. Dict. V. i. (at cited word) Proligerous nucleus, a distinct cartilaginous body coming out from the apothecia of a lichen and containing the sporules. (Greville).

1953 Ann. Missouri Bot. Garden 40 293 Melanotheca angolensis... Pseudostromata thin, ostiole small, without a white annulus; nucleus almost hemispheric or depressed conoid-subspherical.

†e. Mycology. In ascomycetes: the totality of structures within the perithecial wall. Obsolete.

ΚΠ

1832 J. Lindley Introd. Bot. i. iii. 209 Nucleus, is the central part of a perithecium.

1866 J. Lindley & T. Moore Treasury Bot. Nucleus.., the gelatinous mass of asci or spores which is found in the perithecia of Sphæriæ or the analogous fungi.

1875 M. C. Cooke Fungi 79 Fruit consisting of sporidia,..contained in asci,..forming a hymenium or nucleus = Ascomycetes.

1887 H. E. F. Garnsey & I. B. Balfour tr. H. A. de Bary Compar. Morphol. & Biol. Fungi v. 193 Hence the old expression kernel or nucleus of the perithecium, which included..the asci first of all, and then the paraphyses, periphyses, hypothecium, and the soft layers of the wall.

f. The hilum of a starch-granule. Now rare.

ΘΚΠ

the world > plants > part of plant > reproductive part(s) > seed > [noun] > parts of > hilum or cicatrix

hilum1753

cicatrix1826

cicatricula1828

caruncle1830

omphalodium1832

strophiole1839

omphalode1850

nucleus1861

wound stump1923

1861 R. Bentley Man. Bot. i. i. 23 Starch granules, when fully formed, usually present a small rounded spot, which is commonly situated at one end..this is called the hilum or nucleus.

1875 Amer. Naturalist 9 197 If the drying is carried far enough, cracks may be seen extending from the nucleus.

1904 F. W. Oliver et al. tr. A. Kerner von Marilaun Nat. Hist. Plants (ed. 2) I. 460 Many starch-grains exhibit a ‘nucleus’ or hilum which is rich in water, and which is situated excentrically in the grains of the Potato and of Canna.

1957 Encycl. Brit. XXI. 329 a/2 Granules or cells [of starch] which are usually oval in shape are found to be composed of a series of concentric layers arranged round a nucleus or hilum which appears as a dark spot.

†a. Palaeontology. The phragmocone of a belemnite. Obsolete.

ΘΚΠ

the world > life > biology > organism > fossil > [noun] > particular parts of

ostracite1601

horse-head1708

nucleus1734

orthoceras1734

orthoceratite1734

alveolus1747

volutite1802

strombite1811

helicite1828

turbinite1828

phragmocone1843

pro-ostracum1864

orthoceratoid1885

nema1901

1734 Philos. Trans. 1733–4 (Royal Soc.) 38 192 In his note concerning the Belemnites Prussici..he takes notice that the stony Cone, or Nucleus of it, is never found articulate, as in those that come from Sweden.

1747 Philos. Trans. (Royal Soc.) 44 399 Their inner Layer or Nucleus is as equally regular as the outer Crust or whole Body.

1765 Philos. Trans. 1764 (Royal Soc.) 54 42 The conical cavity and its nucleus are always proportioned to the bulk of the Belemnite.

b. Conchology. The first-formed part of the shell of a gastropod (occasionally of a foraminiferan) which forms the basis for subsequent growth; (also) the equivalent part of the operculum of a gastropod.

ΘΚΠ

the world > animals > invertebrates > subkingdom Metazoa > grade Triploblastica or Coelomata > phylum Mollusca > [noun] > Testacea (shelled molluscs) > shelled mollusc > shell > part of

auricle1665

heel1673

lip1681

mouth1681

whirl1681

rib1711

antihelix1721

canal1734

columella1755

vesture1755

body whirl1776

fent1776

pillar1776

pillar-lip1776

septum1786

aperture1794

body whorl1807

costa1812

seam1816

spine1822

umbo1822

varix1822

peristome1828

summit1828

nucleus1833

concameration1835

lunula1835

nympha1836

nymph1839

lunule1842

peritreme1848

body chamber1851

axis1866

umbone1867

liration1904

1833 J. E. Gray in Philos. Trans. (Royal Soc.) 123 772 The embryo shells are generally of a pale horn colour, and destitute of markings: when, therefore, they remain attached to the apex of the spire of adult shells, they may be easily distinguished..; and as, in such cases, they offer some characters of importance, it has been proposed to call them by the name of the Nucleus of the shell.

1851 S. P. Woodward Man. Mollusca i. 36 A rudimental shell..which becomes the nucleus of the adult shell.

1866 R. Tate Plain & Easy Acct. Mollusks Great Brit. iii. 64 The operculum is horny with the nucleus lateral.

1889 H. A. Nicholson & R. Lydekker Man. Palæontol. (ed. 3) I. 682 In the Spiral Gastropods the embryonic shell, or ‘nucleus’, is placed at the apex of the permanent shell.

1901 E. Step Shell Life xv. 253 The operculum is pear-shaped, with the nucleus at the narrow end.

1945 Amer. Midland Naturalist 33 795 The protoconch begins with a small more or less round nucleus.

1980 D. S. Brown Freshwater Snails Afr. ii. 14 Operculum concentric with spiral nucleus, or paucispiral.

6. Anatomy. An anatomically and functionally discrete collection of neurons in the central nervous system. Chiefly with modifying word, or with postmodifying Latin adjectives.lenticular, olivary nucleus etc.: see the first element. See also amygdaloid nucleus n. at amygdaloid adj. and n. Additions 3, nucleus accumbens n., nucleus ambiguus n., nucleus ruber n., suprachiasmatic adj. at supra- prefix 1a(b).

ΘΚΠ

the world > life > the body > nervous system > cerebrospinal axis > [noun] > grey matter > nucleus

nucleus1828

the world > life > the body > nervous system > substance of nervous system > [noun] > nucleus

nucleus1881

1828 J. Quain Elements Anat. x. 622 If a vertical section be made of one of the lobes of the cerebellum, in such a way as that two-thirds of its breadth shall lie external to the incision, an oval nucleus of grey substance (corpus dentatum, vel rhomboideum) will be exposed.

1875 Encycl. Brit. I. 878/1 The upper mass of grey matter projects into the lateral ventricle, and is called the intra-ventricular portion or nucleus caudatus.

1881 St. G. Mivart Cat 271 The third pair of nerves..arise deeply from a grey nucleus..close to the origin of the fourth nerve.

1934 W. B. Pillsbury Fund. Psychol. (ed. 3) ii. 45 The cerebellum..receives ascending or sensory tracts and sends down motor paths by way of the red nucleus.

1968 R. Passmore & J. S. Robson Compan. Med. Stud. I. xix. 12/1 Masses of grey matter are called nuclei, some of which, e.g. the basal nuclei, are large and embedded in the depths of the brain.

1972 Sci. Amer. Dec. 73/1 A sensory pathway consists of peripheral sense organs and several clusters of nerve cells called nuclei. Sensory information is processed in several stages, so that each nucleus receives input from the preceding one, processes the input and sends an output to the next nucleus.

1990 Omni Oct. 76/3 Sometimes a given nucleus can have multiple functions. Take the VMN, near the center of the hypothalamus. If you lesion it, animals cannot be sated; some of these rats become so fat they can barely move.

7. Biology. An organelle that is present in the cells of all organisms except bacteria and similar forms, consisting of a rounded body, enclosed in a double membrane, containing the genetic material of the cell. Also: the nucleoid of a prokaryotic cell (rare).Quot. 1833 at sense 5b is from a paper read to the Linnean Society by Robert Brown in 1831.

ΘΚΠ

the world > life > biology > substance > cell > cell organelle or contents > [noun] > nucleus

nucleus1833

cell nucleus1846

karyosome1894

1833 R. Brown in Trans. Linn. Soc. 16 710 This areola, or nucleus of the cell as perhaps it might be termed.

1842 W. B. Carpenter Princ. Human Physiol. 618 At first having but one nucleus and afterwards presenting several; these nuclei..it is probable..are to be regarded as cytoblasts.

1849 J. H. Balfour Man. Bot. 7 Each cell is found to contain, at some period of its existence, a small body, called a nucleus.

1880 H. C. Bastian Brain 35 Nerve cells are more or less granular bodies, each of which contains a large nucleus.

1882 S. H. Vines tr. J. von Sachs Text-bk. Bot. (ed. 2) 551 In most Monocotyledons the large central nucleus divides, and two fresh nuclei make their appearance.

1918 J. M. Coulter & M. C. Coulter Plant Genetics xv. 152 Endosperm formation begins with free nuclear division, the resulting nuclei being free in the cytoplasm of the sac.

1946 E. A. Steinhaus Insect Microbiol. iv. 194 As the egg nucleus migrates back towards the center of the egg, it unites with the spermatozoon nucleus (pronucleus), producing the so-called fusion nucleus, which now contains the diploid number of chromosomes again.

1962 Brit. Med. Bull. 18 31/1 (heading) Morphology of the bacterial nucleus.

1991 Discover Mar. 73/3 What had been thought of as a floppy little bag of cytoplasmic goo studded with floating organelles—the cell's internal organs, such as the nucleus and the mitochondria—came to be seen as a stiffer structure shaped by a dense forest of fibers.

8. Physics. Originally: (in speculative theories of the atom) a hypothetical core or concentration of mass, charge, etc., supposed to exist at the centre of an atom. In later use: (following the work of Rutherford) the positively charged central core of the atom, comprising most of its mass but occupying only a very small part of its volume, and now known to be composed of protons and (usually) neutrons. Also called atomic nucleus.In Rutherford's first accounts of his work, published in 1911 ( Proc. Manchester Lit. & Philos. Soc. 4 lv. 18 and Philos. Mag. 21 669), it is called only a ‘central charge’.

ΘΚΠ

the world > matter > chemistry > atomic chemistry > [noun] > nucleus

nucleus1844

atomic nucleus1851

nucleant1959

the world > matter > physics > atomic nucleus > [noun]

nucleus1912

1844 M. Faraday in Philos. Mag. 24 141 If, in the ordinary view of atoms, we call the particle of matter away from the powers a, and the system of powers or forces in and around it m, then in Boscovitch's theory a disappears, or is a mere mathematical point... To my mind..the a or nucleus vanishes, and the substance consists of the powers or m.

1851 W. J. M. Rankine in London, Edinb., & Dublin Philos. Mag. 4th Ser. 1 443 The fundamental suppositions of the hypothesis of molecular vortices are the following:—First. That each atom of matter consists of a nucleus or central physical point enveloped by an elastic atmosphere, which is retained around it by attraction.

1851 W. J. M. Rankine in London, Edinb., & Dublin Philos. Mag. 4th Ser. 1 443 If an indefinitely extended vibrating medium..consist of a system of atomic nuclei.

1900 Rep. Brit. Assoc. Advancem. Sci. 1900 619 The material atom must be some kind of permanent nucleus that retains around itself an æthereal field of physical influence.

1900 Rep. Brit. Assoc. Advancem. Sci. 1900 619 If..the distances at which they [sc. atoms] are kept apart are large compared with the diameters of the atomic nuclei.

1903 O. Lodge Mod. Views on Matter 5 If the charge of electricity usually associated with a single monad atom of matter were concentrated on to a spherical nucleus one hundred-thousandth of an atom's dimension in diameter, it would thereby possess a mass about one-thousandth of that of the lightest atom known... Such a hypothetical concentrated unit of electricity it has become customary to call an ‘electron’.

1912 E. Rutherford in London, Edinb., & Dublin Philos. Mag. 6th Ser. 24 461 In a previous paper I have given reasons for believing that the atom consists of a positively charged nucleus of very small dimensions, surrounded by a distribution of electrons in rapid motion, possibly of rings of electrons rotating in one plane.

1919 Conquest 1 i. 36/2 An atom is a sort of solar system in miniature, and comprises a central core or nucleus..and a number of particles, called corpuscles, circulating round the nucleus.

1942 J. D. Stranathan ‘Particles’ of Mod. Physics xi. 417 The nucleus must be very small, not larger than 10⁻¹² cm.

1962 H. D. Bush Atomic & Nucl. Physics iii. 62 The hypothesis that every nucleus consisted of protons and neutrons, was first suggested by Heisenberg (1932).

1999 R. Morris Universe, Eleventh Dimension, & Everything i. iii. 43 Quantum mechanics tells us that an atomic nucleus can possess only certain definite amounts of energy.

9. Chemistry. A central arrangement of atoms, esp. an aromatic ring structure, that is characteristic of a group of organic compounds.

ΘΚΠ

the world > matter > chemistry > chemical structure or stereochemistry > [noun] > ring of atoms

nucleus1845

ring1869

closed chain1904

1845 W. Gregory Outl. Chem. ii. 512 Laurent considers benzole as in some measure the fundamental compound, or nucleus, and calls it phene.

1886 E. F. Smith tr. V. von Richter Chem. Carbon Compounds 465 The azo-group, NN, decomposes, each nitrogen atom remaining attached as NH₂ to a benzene nucleus.

1932 Jrnl. Chem. Soc. 1132 Table III summarises the effect of varying the nature of the side-chain halogen in the compounds with an unsubstituted phenyl nucleus.

1951 I. L. Finar Org. Chem. x. 185 If one acetic acid nucleus is blocked off, the fragment required is ethyl chloroacetate.

1971 Nature 7 May 25/1 Many psychotomimetic substances possess an indole nucleus.

1990 Mutagenesis 5 531/2 This type of mutagenesis does not necessarily require the acridine nucleus.

10. A small colony of bees, including a queen, esp. as used to found a new colony. Also attributive, as nucleus hive, etc.

ΘΚΠ

the world > animals > invertebrates > phylum Arthropoda > class Insecta > order Hymenoptera > [noun] > suborder Apocrita, Petiolata, or Heterophaga > group Aculeata (stinging) > superfamily Apoidea (bees) > group used as foundation for new colony

nucleus1863

1863 L. L. Langstroth Pract. Treat. on Hive & Honey-bee 197 If the colonies are to be multiplied rapidly, the nuclei must never be allowed to become too much reduced in numbers, or to be destitute of brood or honey.

1869 Amer. Naturalist 3 52 The Paper Hornet..often enters my nucleus hives, when I am rearing Italian queen bees, and captures the young queen in the midst of her little colony.

1875 Encycl. Brit. III. 497/2 Nucleus Queen-rearing.

1888 F. R. Cheshire Bees & Bee-keeping II. vii. 306 These small nuclei will sustain themselves, in average seasons.

1915 E. F. Phillips Beekeeping iii. 39 A mere handful of bees (perhaps 200) may constitute a small colony (usually called a nucleus).

1952 H. Mace Bee-keeper's Handbk. xxxiii. 154 Nucleus hives can be purchased or made, either to hold a single nucleus up to four combs, or two or more separate nuclei, separated by partitions.

1976 T. Hooper Guide to Bees & Honey iv. 80 He may buy a full colony, a four or five frame nucleus, or get a swarm.

11. Archaeology. A stone from which flakes have been removed to make implements; a core (cf. core n.¹ 5).

ΘΚΠ

the world > the earth > structure of the earth > constituent materials > stone > [noun] > hard stone > flint > from which implements cut

nucleus1869

1869 J. Lubbock Prehist. Times (ed. 2) iv. 87 These ‘livres de beurre’ appear to have been the blocks or nuclei from which they were obtained.

1877 J. B. Holder Hist. Amer. Fauna in J. Richardson et al. Museum Nat. Hist. III. p. v/2 Among the latter, not fewer than a hundred flint knives, projectiles, sling stones and chips, and among them one of those silicious cores or nuclei, with numerous facets, from which flint flakes or knives had been struck off.

1899 R. Munro Prehist. Scotl. v. 143 Nuclei of obsidian have also been found in Greece.

1917 Jrnl. Royal Anthropol. Inst. Great Brit. & Ireland 47 396 The true nuclei or cores found at the lower level were not numerous, but such as have been recovered demonstrate that flakes were removed in all directions from the parent block, quartzite pebbles being used as hammer-stones.

1939 Science 29 Sept. 297/2 With the animal bones were found typical mousterian-like discoid nuclei.

1977 Kwang-chih Chang Archaeol. Anc. China (ed. 3) ii. 66 The stone implements include in the terminology of the archaeologists reporting..bipolar nuclei and flakes, polyhedral nuclei, flakes, microflakes, [etc.]

12.

a. Phonetics. The most prominent syllable or syllables in a word or utterance; the central or principal part of a syllable (usually the vowel).

ΘΚΠ

the mind > language > linguistics > study of speech sound > speech sound > intonation, pitch, or stress > [noun] > accent > stress accent > stress group > syllables with respect to

subtonic1827

pretone1884

pretonic1892

head1922

nucleus1922

tail1922

peak1935

post-nuclear1944

precontour1945

nuclear1949

tonic1962

1922 H. E. Palmer Eng. Intonation ii. 7 Each Tone-Group contains a Nucleus, which is the stressed syllable of the most prominent word in the Tone-Group. The nucleus corresponds to what is usually called sentence-stress.

1922 H. E. Palmer Eng. Intonation ii. 8 In Southern English there are four characteristic Nucleus Tones.

1941 Language 17 224 The present study..will deal with junctures, stresses, and consonants only in summary, and then devote itself to the syllabic nuclei.

1962 A. C. Gimson Introd. Pronunc. Eng. x. 244 The primary accent (or accents) in a sentence is shown by initiating a change of pitch direction, with the nucleus (falling, rising, or a combination of the two) on the appropriate syllable of the word (or words) on which attention is particularly to be concentrated.

1987 Canad. Jrnl. Linguistics 32 227 In N[orth] A[merican], //t// is deleted when it is followed by an unstressed nucleus and preceded by an //n// that is..preceded by a stressed nucleus.

b. Linguistics. The main or central word or words in a compound, phrase, or sentence; (also) = kernel n.¹ 8b(a).

ΘΚΠ

the mind > language > linguistics > study of grammar > morphology > morpheme > [noun] > stem or base

theme1530

thema1615

crude form1805

base1836

stem1851

base form1864

word base1865

kernel1894

stem-form1928

nucleus1932

base word1935

the mind > language > linguistics > study of grammar > syntax or word order > syntactic unit or constituent > [noun] > minimal sequence

nucleus1932

minimal (also minimum) terminable unit1965

T-unit1965

1932 W. L. Graff Lang. & Langs. v. 202 Subiya, a language of South Africa, classifies all things into twenty-one categories regularly represented by twenty-one different propositions. The indication of one of these categories constitutes the nucleus of the sentence to which everything else is to be subordinated.

1934 R. C. Priebsch & W. E. Collinson German Lang. ii. v. 258 Composite words consisting of a determinant word (Bestimmungswort) and a nucleus (Grundwort). The determinant may be an adjective..or a substantive.

1949 E. A. Nida Morphol. (ed. 2) iv. 83 The nucleus of a morphological construction consists of (1) a root or (2) a combination of roots... The nonnucleus is made up of nonroots. In the construction boyishness the element boy is the nucleus and -ishness constitutes the nonnucleus.

1961 R. B. Long Sentence & its Parts 497 Nucleuses, minimal sequences made up of subjects, predicators, and complements, or of such of these as occur... In come in! the nucleus is made up of the predicator come and the complement in.

1968 J. Lyons Introd. Theoret. Linguistics viii. 334 The subject and the predicate together form the nucleus of the sentence.

II. General uses.

13.

a. A person or group of people that provides or forms the central or originating core, heart, or foundation of a community, society, organization, etc. nucleus crew n. British Navy (now rare) the essential members of a ship's crew; a skeleton crew.

ΚΠ

1753 T. Smollett Ferdinand Count Fathom I. xxxv. 258 Fathom, as usual, formed the nucleus or kernel of the beau monde; and the season soon became so crouded, that many people of fashion were obliged to quit the place for want of lodging.

1798 W. Hutton Life 120 About 700 individuals..were the nucleus of his colony of Georgia.

1853 C. Merivale Fall Rom. Republic v. 150 The few hundred families, which formed the original nucleus of her citizenship.

1868 J. H. Blunt Reformation Church of Eng. II. 95 A Protestant party which crystallized around the nucleus of antisacerdotalists.

1904 Westm. Gaz. 10 Dec. 11/1 They will have a nucleus crew of two-fifths of their war complement.

1914 C. F. Tweney Dict. Naval & Mil. Terms 163 Nucleus crew, the essential members of a ship's crew, such as petty officers, gunners, etc., the crew being raised to full strength in case of mobilisation.

1922 Morning Post 29 Dec. 8/2 A nucleus is a [Communist] Party organisation working inside an organisation.

1965 M. Morse Unattached i. 57 The mood of each rehearsal..depended very much on the attitude of the nucleus group.

1987 Christian Aid News Jan. 7 9/1 Those units were eventually to form the nucleus of the new Sudan People's Liberation Army (SPLA).

b. Of immaterial things: that which is most central or fundamental; a central point, idea, etc., from or around which something can develop or has developed; (of a written or oral composition) the material on which the complete work was based.

ΚΠ

1820 Edinb. Rev. May 314 The nucleus of fine thought is there.

1835 C. Thirlwall Hist. Greece I. vi. 248 They manifestly formed the basis or nucleus of the epic cycle.

1876 ‘G. Eliot’ Daniel Deronda IV. vii. li. 26 Each nucleus of pain or pleasure.

1887 Dict. National Biogr. at W. Christian The original nucleus of the ballad seems to have been composed shortly after Christian's death.

1890 W. James Princ. Psychol. I. 298 Let us settle for ourselves as definitely as we can, just how this central nucleus of the Self may feel, no matter whether it be a spiritual substance or only a delusive word.

1905 E. Wharton House of Mirth i. iii. 53 Lily's beauty..was the last asset in their fortunes, the nucleus around which their life was to be rebuilt.

1927 Amer. Mercury Feb. 232/1 A brief examination of his system of selection will reveal the nucleus of the fiasco.

1992 C. F. Lummis & R. F. Gish Pueblo Indian Folk-stories xvii. 117 (note) We may always depend upon it that there is a nucleus of truth in all these folk-myths.

c. A place, building, etc., which constitutes a centre around which development has taken or can take place; (also) a place which provides the focus for a particular activity.

ΚΠ

1839 G. P. R. James Louis XIV I. 266 A town was the nucleus round which a province, a kingdom, an empire was gathered together.

1865 W. E. H. Lecky Hist. Rationalism II. vi. 261 When a monastery was planted, it soon became the nucleus around which the inhabitants of the neighbourhood clustered.

1872 S. W. Baker Nile Tributaries Abyssinia (new ed.) v. 73 It formed a nucleus for the general gathering of the people with their flocks.

1896 Dict. National Biogr. at R. Le Poor The greater part of his work, recently identified, still remains as the nucleus of the present building.

1910 Encycl. Brit. I. 25/2 The nucleus of the estate was a small farm of 100 acres, called Cartleyhole.

1947 W. Lowrie Art in Early Church iii. 48 The name Lucina..is associated with the burial place of St. Paul and with the earliest nucleus of the cemetery of Callistus.

1984 J. Morris Journeys (1985) 129 The tight, tough island quarter called Garnla Stan, Old Town, the original nucleus of the city.

d. A collection or group of things which forms the core or foundation for a larger collection or group; a sum of money which forms the basis of a larger amount.

ΚΠ

1857 T. Hughes Tom Brown's School Days ii. iv. 309 The kestrel's eggs..formed the nucleus of Arthur's collection.

1863 C. Reade Hard Cash II. xi. 139 With your abilities and experience five thousand pounds may yet be the nucleus of a fortune.

1870 J. H. Bennet Winter & Spring Mediterranean viii. 221 There is already a very fair collection of modern books in hand, as the nucleus of a library.

1899 J. Sartain Reminisc. Very Old Man i. 17 Sir Hans Sloane, whose collection became the nucleus of the present fine assemblage of curious and beautiful objects housed in the British Museum.

1921 A. R. Williams Through Russ. Revol. v. 84 The club boasted a much-used magazine room, the nucleus of a library, and an excellent illustrated weekly.

1940 L. P. Stebbins Enchanted Wanderer xix. 286 There had been a residue of money and it was proposed to make this the nucleus of a fund for a monument.

1998 M. Jacobs Budapest 118 The present light and airy setting..makes for an excellent, clear display of the old Hungarian instruments that form the nucleus of the collections.

This entry has been updated (OED Third Edition, December 2003; most recently modified version published online June 2022).

单词	nucleus
释义	nucleusn. Brit. /ˈnjuːklɪəs/, U.S. /ˈn(j)ukliəs/ Inflections: Plural nuclei Brit. /ˈnjuːklɪʌɪ/, U.S. /ˈn(j)ukliˌaɪ/, (rare) nucleuses. Origin: A borrowing from Latin. Etymon: Latin nucleus. Etymology: < classical Latin nucleus (also nuculeus ) kernel, inner part, in post-classical Latin also core of a comet (1668 J. Hevelius Cometographia), central idea (1672), concentric layer within the earth (1702) < nuci- , nux nut (see nut n.¹) + -leus , suffix forming diminutives. Compare Spanish núcleo (1490 in sense 4a), Italian nucleo (a1674), French nucléus (1845), Portuguese núcleo (1858). I. In scientific and other technical uses. 1. Astronomy. a. Originally: a bright core forming the main part of the visible head of a comet or (occasionally) a meteor. Now: spec. the solid central core of a comet, composed of ice and dust. ΘΚΠ the world > the universe > constellation > comet or meteor > comet > [noun] > head > nucleus nucleus1668 1668 Philos. Trans. (Royal Soc.) 3 807 Comets may more or less deviate from that streightness, both in appearance, and really;..the latter [arising] from the matter of their Bodies and Nucleus's (as he [sc. J. Hevelius] calls the substance of their Head) not increasing nor decreasing uniformly on all sides. 1678 R. Hooke Lect. & Coll. 3 The Comet, the middle of which appeared brighter than any other part;..and seemed to issue from the Nucleus or Star in the middle of the head. 1708 W. Whiston New Theory of Earth (ed. 2) ii. 76 The lowest part next the Nucleus, or Dense Body seems to be Opake. 1726 J. Swift Gulliver II. iii. ii. 30 If the Earth should pass at the Distance of one hundred thousand Miles from the Nucleus or main Body of the Comet, it must in its Passage be set on fire, and reduced to Ashes. 1784 Philos. Trans. (Royal Soc.) 74 458 It [sc. a meteor] became extinct in the S.S.E. a few sparks of the tail, nearest the nucleus, scattering themselves much in the same manner as those of a sky-rocket when burnt out. 1837 J. F. Cooper Recoll. Europe II. v. 99 The astronomers tell us that some of these comets have no visible nucleuses. 1868 J. N. Lockyer Elem. Lessons Astron. §291 The brighter part of the comet is called the head, or coma, and sometimes the head contains a brighter portion still, called the nucleus. 1887 Cent. Mag. Jan. 348/2 If we agree that meteorites were once part of a comet, say that it now seems probable that the nucleus is a hard, stone-like mass, or collection of such masses, which comes from ‘space’. 1929 Science 9 Aug. 133/1 N. T. Bobrovnikoff explained that the repulsive forces near the nucleus of Halley's comet are two to six times the gravitational force of the sun. 1950 Astrophysical Jrnl. 111 376 I propose to investigate the possibility that the molecules responsible for most of the light of comets near perihelion arise primarily from gases long frozen in the nuclei of comets. 1995 Astron. Now Dec. 4 New pictures from NASA's Hubble Space Telescope of the recently discovered comet Hale-Bopp show..a ‘Blob’ of free-flying debris near the comet's nucleus. b. The darker central part of a sunspot. Now rare.Now usually called umbra: see umbra n.¹ 4b. ΚΠ 1684 J. Flamsteed in Philos. Trans. (Royal Soc.) 14 536 When the Spot was near the middle of the Sun it appeared very broad and almost square, the Nucleus of the same Figure about 40″ diameter. 1712 Philos. Trans. 1710–12 (Royal Soc.) 27 275 Another thing that may be accounted for..is the Nuclei, or darker part of the Spots; generally in most Spots, and towards the middle of them. 1774 Philos. Trans. (Royal Soc.) 64 6 It was pleasant to see the nucleus of the spot, and the shady zone or umbra which surrounded it, so very distinct. 1871 R. A. Proctor Sun iv. 167 Spots such as the one observed by Cassini seldom exhibit the peculiarity in question [sc. the Wilson effect] in a manner which would enable the observer to theorise safely respecting the level at which nucleus, penumbra, and photosphere actually lie. 1884 Science 26 Dec. 564/1 According to the observations of Professor Langley, the black nucleus or umbra of a spot emits only about fifty-four per cent as much heat as an equal area of the normal surface. 1905 Proc. Royal Soc. 1904–5 74 54 The temperature of the Arcturian absorbing atmosphere is about the same as that of the sunspot nuclei. 1977 Jrnl. Royal Statist. Soc. A. 140 454 This change was due to an alteration in the method of counting sunspot nuclei. c. A denser, usually brighter, central part of a galaxy or nebula. ΘΚΠ the world > the universe > constellation > galaxy > [noun] > nucleus nucleus1784 the world > the universe > constellation > nebula > [noun] > nucleus nucleus1784 1784 W. Herschel in Philos. Trans. (Royal Soc.) 74 443 I have seen double and treble nebulæ, variously arranged; large ones with small, seeming attendants;..others of the cometic shape, with a seeming nucleus in the center. 1811 W. Herschel Philos. Trans. (Royal Soc.) 101 307 In the following eighteen nebulæ we may see a still more advanced compression of it, amounting almost to the appearance of a nucleus. 1849 J. F. W. Herschel Outl. Astron. xvii. 601 The nebula in Andromeda..is visible to the naked eye... Mr. G. P. Bond, assistant at the observatory of Cambridge, U.S., describes and figures it as..very suddenly condensed at the nucleus almost to the semblance of a star. 1898 A. M. Clerke et al. Conc. Knowl. Astron. iv. vi. 534 The photograph shows both nuclei of the nebula to be stellar. 1955 Sci. Amer. May 48/3 Because of heavy dust clouds this nucleus [of the Milky Way] has not been observed visually or photographically; it was discovered by radio astronomy. 1970 Sci. Jrnl. Feb. 61/1 The emission line spectrum of a Seyfert nucleus is rather like that from typical hot clouds of gas such as the Orion Nebula. 1992 S. P. Maran Astron. & Astrophysics Encycl. 261/2 The nucleus of a galaxy is not a precisely defined entity or distinct subcomponent. 2. The core or central part of the earth or other planet (variously conceived according to the scientific thought of the time). Hence (formerly): (in some theories) †each of a supposed series of concentric layers within the earth (obsolete). Now rare in technical use. ΘΚΠ the world > the earth > structure of the earth > [noun] > crust > supposed interior crust nucleus1693 1693 E. Halley in Philos. Trans. (Royal Soc.) 16 568 The External Parts of the Globe may well be reckoned as the Shell, and the internal as a Nucleus or inner Globe included within ours, with a fluid medium between... If the Internal Nucleus be likewise a Magnet, having its Poles in two other places distant also from the Axis..; we may than give a reasonable account..of the changes of the Needles Variations. 1715 tr. D. Gregory Elements Astron. I. i. §69. 144 He [sc. Kepler] found it necessary to suppose an interior Crust (which might be like a Nucleus, in regard of the exterior). 1715 tr. D. Gregory Elements Astron. I. i. §69. 145 And within this Nucleus, or rather Crust, he is forced to suppose again another interior Nucleus. 1741 Mem. Martinus Scriblerus 68 in A. Pope Wks. II A Proposal..to pierce the first crust or Nucleus of this our Earth, quite through, to the next concentrical Sphere. a1802 E. Darwin Temple of Nature (1803) iv. 164 (note) It seems clearly to appear, that the nucleus of the globe beneath the ocean consisted of granite. 1828 H. Davy in Philos. Trans. (Royal Soc.) 118 250 The hypothesis of the nucleus of the globe being composed of fluid matter, offers a still more simple solution of the phænomena of volcanic fires. 1851 Abstr. Papers Royal Soc. 1843–50 5 807 His object here is to discover..the effects of the reaction of the fluid nucleus..upon the solid crust. 1929 Science 20 Dec. 589/1 The great deformations in the earth's crust have been caused by a cooling of the interior of the earth and the collapse of the crust to fit the reduced area of the surface of the nucleus. 1957 A. Synge tr. A. I. Oparin Origin Life on Earth iv. 125 In the centre of the Earth..there is a nucleus which is far denser than the superficial formations. 1984 D. Keane Universe & Other Poems 33 Jupiter..resembles the sun more than the earth, a massive drop of liquid hydrogen about an iron nucleus. 3. a. The centre or core of a material object; esp. a central part or thing around which other parts or things are grouped or collected; the centre or kernel of an aggregate or concretion.Now usually in any of various technical applications, as (Anatomy) the interior part of the lens of the eye, or of an intervertebral disc (cf. nucleus pulposus n.), (Geology) the central portion of a section of continental crust, etc. ΘΚΠ the world > space > relative position > central condition or position > [noun] > central part > central or innermost part hearteOE yolk1340 centruma1398 marrow1434 core1614 kernela1642 centrals1649 nucleus1702 centrepiece1739 1702 Philos. Trans. (Royal Soc.) 23 1284 These Balls seem to be form'd something after the manner of Bezoars, which generally have some seed for their Center or nucleus, on which Coats of another substance are gathered. 1744 Philos. Trans. 1740–41 (Royal Soc.) 41 460 In the 15th [section], he refutes..Huygen's Manner of accounting for Haloes, which is by a vast Number of very small Vapours, each with a snowy Nucleus, coated round with a transparent covering. 1793 M. Baillie Morbid Anat. xiv. 202 Some extraneous body, which becomes the nucleus of the calculus. 1819 S. Cooper First Lines Pract. Surg. (ed. 4) I. ii. vii. 85 Every portion of the gangrenous cellular membrane, or nucleus extracted. 1837 Abstr. Papers Royal Soc. 1830–37 3 340 There is, at first sight, a considerable resemblance between the nucleus of the vesicle of De Graaf and the immature yelk of the egg of a bird. 1877 T. H. Huxley Man. Anat. Invertebrated Animals x. 619 The relatively small alimentary and reproductive viscera are sometimes aggregated into a mass, the so-called nucleus, at the posterior end of the hæmal side of the body. 1939 Sci. Monthly Nov. 451 In central Asia the east-west trends are seen to be composed of arcs which frame the nuclei of ancient rocks. 1942 D. G. Cogen in A. Pirie Lens Metabolism 293 The morphological difference between the cortex, constituting the outer layers of the lens substance, and the nucleus, constituting the inner portion, is the difference in integrity of lens fibres. 1987 S. Sandler Osteopathy ii. 24 Sometimes the trauma is very great and the annulus actually ruptures or splits completely. Then a piece of the soft nucleus is squeezed out of the disc in the way that toothpaste is squeezed out of a tube. †b. Mineralogy. The most simple or basic form to which a crystal may be reduced by successive cleavage, corresponding to the fundamental form of the system in which it crystallizes. Obsolete. ΚΠ 1798 Philos. Trans. (Royal Soc.) 88 429 The regular hexaedral prism of these crystals, cannot..be considered as the form of the nucleus of the crystal; and consequently is not the primitive form of the crystals of this substance. 1816 R. Jameson Treat. External Characters Minerals (ed. 2) 131 We obtain a regular figure, whose contour is very different from that which the crystal first exhibited, and which may now be further subdivided in the direction of its planes, without undergoing any further change of form. This new regular form is by Hauy named the Primitive nucleus; and the crystal whose form is the same, the Primitive form. 1855 J. D. Dana Man. Mineral. (ed. 7) ii. 23 They..have the same nucleus or fundamental form. c. Chemistry. A particle in a fluid on which a crystal, droplet, or bubble can form; (originally) a particle that initiates nucleation, a nucleant; (in later technical use) a small crystal, droplet, or bubble formed spontaneously in a homogeneous metastable phase which is large enough to be stable and continue to grow. Also, in extended use (Materials Science): a flaw by which a crack in a crystalline or other solid material can be initiated. ΘΚΠ the world > matter > chemistry > crystallography (general) > crystal (general) > crystals (other miscellaneous) > [noun] > a particle on which crystals, droplets or bubbles can form nucleus1815 1815 H. Davy in Philos. Trans. (Royal Soc.) 105 111 Amongst the substances found in the baths of Titus were some masses of a grass green colour... They proved..to be carbonate of copper, but it had formed round longitudinal nuclei of red oxide of copper. 1857 W. A. Miller Elements Chem.: Org. (1862) ii. §1. 90 Small pieces of wood are then introduced to act as nuclei upon which the crystals of lactose are deposited. 1886 Proc. Royal Soc. Edinb. 13 79 If this were the case, no nucleus would be absolutely requisite for the formation either of liquid from vapour or of vapour from liquid. 1922 T. M. Lowry Inorg. Chem. xxix. 494 The local deposition of amorphous silica around nuclei of organic matter in beds of chalk. 1952 Industr. & Engin. Chem. June 1273/1 A nucleus in water-fog formation consists of about 80 water molecules. 1967 A. H. Cottrell Introd. Metall. xii. 154 When the probability of forming a nucleus is the same everywhere, the system is in a state suitable for homogeneous nucleation. 1989 A. C. Davies Sci. & Pract. Welding (ed. 9) I. ii. 150 Faults in a weld such as slag inclusion..may serve as nuclei for a crack from which the brittle fracture may be projected. 1990 C. Pellant Rocks, Minerals & Fossils 45/3 The ooliths are small.., rounded or sub-rounded grains made of concentric layers of calcite precipitated around a nucleus. 4. Botany. †a. The innermost, often edible portion of a nut. Obsolete. ΘΚΠ the world > plants > part of plant > reproductive part(s) > fruit or reproductive product > nut > [noun] > kernel nut kerneleOE kernelc1000 gristle?1537 kern1570 nucleus1704 nut-meat1860 1704 J. Harris Lexicon Technicum I Nucleus is the Edible part of the Kernel of any Nut, which is contained within the Skin of the Kernel. 1738 E. Chambers Cycl. (ed. 2) at Nut A hard cortex, or shell; which contains a softer edible nucleus, or kernel. 1785 T. Martyn tr. J.-J. Rousseau Lett. Elements Bot. xxviii. 439 The fruit is a drupe containing a nut, with a furrowed shell, within which is a four-lobed, irregularly furrowed nucleus. 1845 A. Wood Class-bk. Bot. ii. 338 J. cinerea..nucleus oblong, acuminate, deeply and irregularly furrowed. †b. The part of a seed enclosed by integuments. Obsolete. ΘΚΠ the world > plants > part of plant > reproductive part(s) > seed > [noun] > parts of > body within covering nucleus1704 kernel1796 1704 J. Harris Lexicon Technicum I Nucleus..in a larger sense is by Botanists used for any Fruit or Seed contained within an Husk or Shell. 1745 Philos. Trans. 1744–5 (Royal Soc.) 43 186 The second Specimen is that of the Angelica... When [t]he Husk is pull'd off, the Nucleus appears of a brownish Colour, and its Shape is elliptical. 1829 P. Clinton tr. A. Richard New Elem. Bot. (ed. 4) 387 The kernel or nucleus is the whole of the ripe and perfect seed contained in the cavity of the episperm. 1861 R. Bentley Man. Bot. i. iv. 343 The nucleus of the seed may either consist of the embryo alone..or of the embryo enclosed in albumen or perisperm. 1877 Philos. Trans. (Royal Soc.) 167 244 Towards the lower part of the seed we only see traces of one membrane..investing the nucleus. 1908 B. L. Robinson & M. L. Fernald Gray's New Man. Bot. (ed. 7) 880/2 Nucleus, the kernel of a seed.] c. The nucellus of an ovule. Now disused. ΘΚΠ the world > life > biology > biological processes > procreation or reproduction > reproductive substances or cells > [noun] > ovum or ootid > nucleus nucleus1827 Purkinje's vesicle1836 1827 R. Brown Char. & Descr. Kingia in P. P. King Narr. Surv. Intertropical Coasts Austral. II. App. 540 I had ascertained that in Phænogamous plants the unimpregnated Ovulum very generally consisted of two concentric membranes or coats, enclosing a Nucleus of a pulpy cellular texture. 1829 P. Clinton tr. A. Richard New Elem. Bot. (ed. 4) 383 The nucleus contained within both the integuments of the ovule is a cellular body. 1832 J. Lindley Introd. Bot. i. ii. 155 The central part is a fleshy, pointed, pulpy mass, called the nucleus or nucelle. 1861 R. Bentley Man. Bot. ii. iv. 330 As development proceeds a cavity is formed at or near the apex of the nucleus..in which the embryo..is developed. 1904 F. W. Oliver et al. tr. A. Kerner von Marilaun Nat. Hist. Plants (ed. 2) I. 644 In them [sc. the ovules] may be distinguished the nucellus (nucleus), surrounded by two, or less frequently only one coat (integumentum). d. In lichens: the disc of an apothecium. Now rare. ΚΠ 1832 J. Lindley Introd. Bot. i. iii. 206 Nucleus, is the disk of the shield which contains the sporules and their cases. Asci, are tubes, in which the sporules are contained while in the nucleus. 1882 Encycl. Brit. XIV. 554/2 When the pyrenium quite covers the nucleus it is said to be entire. 1885 Cassell's Encycl. Dict. V. i. (at cited word) Proligerous nucleus, a distinct cartilaginous body coming out from the apothecia of a lichen and containing the sporules. (Greville). 1953 Ann. Missouri Bot. Garden 40 293 Melanotheca angolensis... Pseudostromata thin, ostiole small, without a white annulus; nucleus almost hemispheric or depressed conoid-subspherical. †e. Mycology. In ascomycetes: the totality of structures within the perithecial wall. Obsolete. ΚΠ 1832 J. Lindley Introd. Bot. i. iii. 209 Nucleus, is the central part of a perithecium. 1866 J. Lindley & T. Moore Treasury Bot. Nucleus.., the gelatinous mass of asci or spores which is found in the perithecia of Sphæriæ or the analogous fungi. 1875 M. C. Cooke Fungi 79 Fruit consisting of sporidia,..contained in asci,..forming a hymenium or nucleus = Ascomycetes. 1887 H. E. F. Garnsey & I. B. Balfour tr. H. A. de Bary Compar. Morphol. & Biol. Fungi v. 193 Hence the old expression kernel or nucleus of the perithecium, which included..the asci first of all, and then the paraphyses, periphyses, hypothecium, and the soft layers of the wall. f. The hilum of a starch-granule. Now rare. ΘΚΠ the world > plants > part of plant > reproductive part(s) > seed > [noun] > parts of > hilum or cicatrix hilum1753 cicatrix1826 cicatricula1828 caruncle1830 omphalodium1832 strophiole1839 omphalode1850 nucleus1861 wound stump1923 1861 R. Bentley Man. Bot. i. i. 23 Starch granules, when fully formed, usually present a small rounded spot, which is commonly situated at one end..this is called the hilum or nucleus. 1875 Amer. Naturalist 9 197 If the drying is carried far enough, cracks may be seen extending from the nucleus. 1904 F. W. Oliver et al. tr. A. Kerner von Marilaun Nat. Hist. Plants (ed. 2) I. 460 Many starch-grains exhibit a ‘nucleus’ or hilum which is rich in water, and which is situated excentrically in the grains of the Potato and of Canna. 1957 Encycl. Brit. XXI. 329 a/2 Granules or cells [of starch] which are usually oval in shape are found to be composed of a series of concentric layers arranged round a nucleus or hilum which appears as a dark spot. 5. †a. Palaeontology. The phragmocone of a belemnite. Obsolete. ΘΚΠ the world > life > biology > organism > fossil > [noun] > particular parts of ostracite1601 horse-head1708 nucleus1734 orthoceras1734 orthoceratite1734 alveolus1747 volutite1802 strombite1811 helicite1828 turbinite1828 phragmocone1843 pro-ostracum1864 orthoceratoid1885 nema1901 1734 Philos. Trans. 1733–4 (Royal Soc.) 38 192 In his note concerning the Belemnites Prussici..he takes notice that the stony Cone, or Nucleus of it, is never found articulate, as in those that come from Sweden. 1747 Philos. Trans. (Royal Soc.) 44 399 Their inner Layer or Nucleus is as equally regular as the outer Crust or whole Body. 1765 Philos. Trans. 1764 (Royal Soc.) 54 42 The conical cavity and its nucleus are always proportioned to the bulk of the Belemnite. b. Conchology. The first-formed part of the shell of a gastropod (occasionally of a foraminiferan) which forms the basis for subsequent growth; (also) the equivalent part of the operculum of a gastropod. ΘΚΠ the world > animals > invertebrates > subkingdom Metazoa > grade Triploblastica or Coelomata > phylum Mollusca > [noun] > Testacea (shelled molluscs) > shelled mollusc > shell > part of auricle1665 heel1673 lip1681 mouth1681 whirl1681 rib1711 antihelix1721 canal1734 columella1755 vesture1755 body whirl1776 fent1776 pillar1776 pillar-lip1776 septum1786 aperture1794 body whorl1807 costa1812 seam1816 spine1822 umbo1822 varix1822 peristome1828 summit1828 nucleus1833 concameration1835 lunula1835 nympha1836 nymph1839 lunule1842 peritreme1848 body chamber1851 axis1866 umbone1867 liration1904 1833 J. E. Gray in Philos. Trans. (Royal Soc.) 123 772 The embryo shells are generally of a pale horn colour, and destitute of markings: when, therefore, they remain attached to the apex of the spire of adult shells, they may be easily distinguished..; and as, in such cases, they offer some characters of importance, it has been proposed to call them by the name of the Nucleus of the shell. 1851 S. P. Woodward Man. Mollusca i. 36 A rudimental shell..which becomes the nucleus of the adult shell. 1866 R. Tate Plain & Easy Acct. Mollusks Great Brit. iii. 64 The operculum is horny with the nucleus lateral. 1889 H. A. Nicholson & R. Lydekker Man. Palæontol. (ed. 3) I. 682 In the Spiral Gastropods the embryonic shell, or ‘nucleus’, is placed at the apex of the permanent shell. 1901 E. Step Shell Life xv. 253 The operculum is pear-shaped, with the nucleus at the narrow end. 1945 Amer. Midland Naturalist 33 795 The protoconch begins with a small more or less round nucleus. 1980 D. S. Brown Freshwater Snails Afr. ii. 14 Operculum concentric with spiral nucleus, or paucispiral. 6. Anatomy. An anatomically and functionally discrete collection of neurons in the central nervous system. Chiefly with modifying word, or with postmodifying Latin adjectives.lenticular, olivary nucleus etc.: see the first element. See also amygdaloid nucleus n. at amygdaloid adj. and n. Additions 3, nucleus accumbens n., nucleus ambiguus n., nucleus ruber n., suprachiasmatic adj. at supra- prefix 1a(b). ΘΚΠ the world > life > the body > nervous system > cerebrospinal axis > [noun] > grey matter > nucleus nucleus1828 the world > life > the body > nervous system > substance of nervous system > [noun] > nucleus nucleus1881 1828 J. Quain Elements Anat. x. 622 If a vertical section be made of one of the lobes of the cerebellum, in such a way as that two-thirds of its breadth shall lie external to the incision, an oval nucleus of grey substance (corpus dentatum, vel rhomboideum) will be exposed. 1875 Encycl. Brit. I. 878/1 The upper mass of grey matter projects into the lateral ventricle, and is called the intra-ventricular portion or nucleus caudatus. 1881 St. G. Mivart Cat 271 The third pair of nerves..arise deeply from a grey nucleus..close to the origin of the fourth nerve. 1934 W. B. Pillsbury Fund. Psychol. (ed. 3) ii. 45 The cerebellum..receives ascending or sensory tracts and sends down motor paths by way of the red nucleus. 1968 R. Passmore & J. S. Robson Compan. Med. Stud. I. xix. 12/1 Masses of grey matter are called nuclei, some of which, e.g. the basal nuclei, are large and embedded in the depths of the brain. 1972 Sci. Amer. Dec. 73/1 A sensory pathway consists of peripheral sense organs and several clusters of nerve cells called nuclei. Sensory information is processed in several stages, so that each nucleus receives input from the preceding one, processes the input and sends an output to the next nucleus. 1990 Omni Oct. 76/3 Sometimes a given nucleus can have multiple functions. Take the VMN, near the center of the hypothalamus. If you lesion it, animals cannot be sated; some of these rats become so fat they can barely move. 7. Biology. An organelle that is present in the cells of all organisms except bacteria and similar forms, consisting of a rounded body, enclosed in a double membrane, containing the genetic material of the cell. Also: the nucleoid of a prokaryotic cell (rare).Quot. 1833 at sense 5b is from a paper read to the Linnean Society by Robert Brown in 1831. ΘΚΠ the world > life > biology > substance > cell > cell organelle or contents > [noun] > nucleus nucleus1833 cell nucleus1846 karyosome1894 1833 R. Brown in Trans. Linn. Soc. 16 710 This areola, or nucleus of the cell as perhaps it might be termed. 1842 W. B. Carpenter Princ. Human Physiol. 618 At first having but one nucleus and afterwards presenting several; these nuclei..it is probable..are to be regarded as cytoblasts. 1849 J. H. Balfour Man. Bot. 7 Each cell is found to contain, at some period of its existence, a small body, called a nucleus. 1880 H. C. Bastian Brain 35 Nerve cells are more or less granular bodies, each of which contains a large nucleus. 1882 S. H. Vines tr. J. von Sachs Text-bk. Bot. (ed. 2) 551 In most Monocotyledons the large central nucleus divides, and two fresh nuclei make their appearance. 1918 J. M. Coulter & M. C. Coulter Plant Genetics xv. 152 Endosperm formation begins with free nuclear division, the resulting nuclei being free in the cytoplasm of the sac. 1946 E. A. Steinhaus Insect Microbiol. iv. 194 As the egg nucleus migrates back towards the center of the egg, it unites with the spermatozoon nucleus (pronucleus), producing the so-called fusion nucleus, which now contains the diploid number of chromosomes again. 1962 Brit. Med. Bull. 18 31/1 (heading) Morphology of the bacterial nucleus. 1991 Discover Mar. 73/3 What had been thought of as a floppy little bag of cytoplasmic goo studded with floating organelles—the cell's internal organs, such as the nucleus and the mitochondria—came to be seen as a stiffer structure shaped by a dense forest of fibers. 8. Physics. Originally: (in speculative theories of the atom) a hypothetical core or concentration of mass, charge, etc., supposed to exist at the centre of an atom. In later use: (following the work of Rutherford) the positively charged central core of the atom, comprising most of its mass but occupying only a very small part of its volume, and now known to be composed of protons and (usually) neutrons. Also called atomic nucleus.In Rutherford's first accounts of his work, published in 1911 ( Proc. Manchester Lit. & Philos. Soc. 4 lv. 18 and Philos. Mag. 21 669), it is called only a ‘central charge’. ΘΚΠ the world > matter > chemistry > atomic chemistry > [noun] > nucleus nucleus1844 atomic nucleus1851 nucleant1959 the world > matter > physics > atomic nucleus > [noun] nucleus1912 1844 M. Faraday in Philos. Mag. 24 141 If, in the ordinary view of atoms, we call the particle of matter away from the powers a, and the system of powers or forces in and around it m, then in Boscovitch's theory a disappears, or is a mere mathematical point... To my mind..the a or nucleus vanishes, and the substance consists of the powers or m. 1851 W. J. M. Rankine in London, Edinb., & Dublin Philos. Mag. 4th Ser. 1 443 The fundamental suppositions of the hypothesis of molecular vortices are the following:—First. That each atom of matter consists of a nucleus or central physical point enveloped by an elastic atmosphere, which is retained around it by attraction. 1851 W. J. M. Rankine in London, Edinb., & Dublin Philos. Mag. 4th Ser. 1 443 If an indefinitely extended vibrating medium..consist of a system of atomic nuclei. 1900 Rep. Brit. Assoc. Advancem. Sci. 1900 619 The material atom must be some kind of permanent nucleus that retains around itself an æthereal field of physical influence. 1900 Rep. Brit. Assoc. Advancem. Sci. 1900 619 If..the distances at which they [sc. atoms] are kept apart are large compared with the diameters of the atomic nuclei. 1903 O. Lodge Mod. Views on Matter 5 If the charge of electricity usually associated with a single monad atom of matter were concentrated on to a spherical nucleus one hundred-thousandth of an atom's dimension in diameter, it would thereby possess a mass about one-thousandth of that of the lightest atom known... Such a hypothetical concentrated unit of electricity it has become customary to call an ‘electron’. 1912 E. Rutherford in London, Edinb., & Dublin Philos. Mag. 6th Ser. 24 461 In a previous paper I have given reasons for believing that the atom consists of a positively charged nucleus of very small dimensions, surrounded by a distribution of electrons in rapid motion, possibly of rings of electrons rotating in one plane. 1919 Conquest 1 i. 36/2 An atom is a sort of solar system in miniature, and comprises a central core or nucleus..and a number of particles, called corpuscles, circulating round the nucleus. 1942 J. D. Stranathan ‘Particles’ of Mod. Physics xi. 417 The nucleus must be very small, not larger than 10⁻¹² cm. 1962 H. D. Bush Atomic & Nucl. Physics iii. 62 The hypothesis that every nucleus consisted of protons and neutrons, was first suggested by Heisenberg (1932). 1999 R. Morris Universe, Eleventh Dimension, & Everything i. iii. 43 Quantum mechanics tells us that an atomic nucleus can possess only certain definite amounts of energy. 9. Chemistry. A central arrangement of atoms, esp. an aromatic ring structure, that is characteristic of a group of organic compounds. ΘΚΠ the world > matter > chemistry > chemical structure or stereochemistry > [noun] > ring of atoms nucleus1845 ring1869 closed chain1904 1845 W. Gregory Outl. Chem. ii. 512 Laurent considers benzole as in some measure the fundamental compound, or nucleus, and calls it phene. 1886 E. F. Smith tr. V. von Richter Chem. Carbon Compounds 465 The azo-group, NN, decomposes, each nitrogen atom remaining attached as NH₂ to a benzene nucleus. 1932 Jrnl. Chem. Soc. 1132 Table III summarises the effect of varying the nature of the side-chain halogen in the compounds with an unsubstituted phenyl nucleus. 1951 I. L. Finar Org. Chem. x. 185 If one acetic acid nucleus is blocked off, the fragment required is ethyl chloroacetate. 1971 Nature 7 May 25/1 Many psychotomimetic substances possess an indole nucleus. 1990 Mutagenesis 5 531/2 This type of mutagenesis does not necessarily require the acridine nucleus. 10. A small colony of bees, including a queen, esp. as used to found a new colony. Also attributive, as nucleus hive, etc. ΘΚΠ the world > animals > invertebrates > phylum Arthropoda > class Insecta > order Hymenoptera > [noun] > suborder Apocrita, Petiolata, or Heterophaga > group Aculeata (stinging) > superfamily Apoidea (bees) > group used as foundation for new colony nucleus1863 1863 L. L. Langstroth Pract. Treat. on Hive & Honey-bee 197 If the colonies are to be multiplied rapidly, the nuclei must never be allowed to become too much reduced in numbers, or to be destitute of brood or honey. 1869 Amer. Naturalist 3 52 The Paper Hornet..often enters my nucleus hives, when I am rearing Italian queen bees, and captures the young queen in the midst of her little colony. 1875 Encycl. Brit. III. 497/2 Nucleus Queen-rearing. 1888 F. R. Cheshire Bees & Bee-keeping II. vii. 306 These small nuclei will sustain themselves, in average seasons. 1915 E. F. Phillips Beekeeping iii. 39 A mere handful of bees (perhaps 200) may constitute a small colony (usually called a nucleus). 1952 H. Mace Bee-keeper's Handbk. xxxiii. 154 Nucleus hives can be purchased or made, either to hold a single nucleus up to four combs, or two or more separate nuclei, separated by partitions. 1976 T. Hooper Guide to Bees & Honey iv. 80 He may buy a full colony, a four or five frame nucleus, or get a swarm. 11. Archaeology. A stone from which flakes have been removed to make implements; a core (cf. core n.¹ 5). ΘΚΠ the world > the earth > structure of the earth > constituent materials > stone > [noun] > hard stone > flint > from which implements cut nucleus1869 1869 J. Lubbock Prehist. Times (ed. 2) iv. 87 These ‘livres de beurre’ appear to have been the blocks or nuclei from which they were obtained. 1877 J. B. Holder Hist. Amer. Fauna in J. Richardson et al. Museum Nat. Hist. III. p. v/2 Among the latter, not fewer than a hundred flint knives, projectiles, sling stones and chips, and among them one of those silicious cores or nuclei, with numerous facets, from which flint flakes or knives had been struck off. 1899 R. Munro Prehist. Scotl. v. 143 Nuclei of obsidian have also been found in Greece. 1917 Jrnl. Royal Anthropol. Inst. Great Brit. & Ireland 47 396 The true nuclei or cores found at the lower level were not numerous, but such as have been recovered demonstrate that flakes were removed in all directions from the parent block, quartzite pebbles being used as hammer-stones. 1939 Science 29 Sept. 297/2 With the animal bones were found typical mousterian-like discoid nuclei. 1977 Kwang-chih Chang Archaeol. Anc. China (ed. 3) ii. 66 The stone implements include in the terminology of the archaeologists reporting..bipolar nuclei and flakes, polyhedral nuclei, flakes, microflakes, [etc.] 12. a. Phonetics. The most prominent syllable or syllables in a word or utterance; the central or principal part of a syllable (usually the vowel). ΘΚΠ the mind > language > linguistics > study of speech sound > speech sound > intonation, pitch, or stress > [noun] > accent > stress accent > stress group > syllables with respect to subtonic1827 pretone1884 pretonic1892 head1922 nucleus1922 tail1922 peak1935 post-nuclear1944 precontour1945 nuclear1949 tonic1962 1922 H. E. Palmer Eng. Intonation ii. 7 Each Tone-Group contains a Nucleus, which is the stressed syllable of the most prominent word in the Tone-Group. The nucleus corresponds to what is usually called sentence-stress. 1922 H. E. Palmer Eng. Intonation ii. 8 In Southern English there are four characteristic Nucleus Tones. 1941 Language 17 224 The present study..will deal with junctures, stresses, and consonants only in summary, and then devote itself to the syllabic nuclei. 1962 A. C. Gimson Introd. Pronunc. Eng. x. 244 The primary accent (or accents) in a sentence is shown by initiating a change of pitch direction, with the nucleus (falling, rising, or a combination of the two) on the appropriate syllable of the word (or words) on which attention is particularly to be concentrated. 1987 Canad. Jrnl. Linguistics 32 227 In N[orth] A[merican], //t// is deleted when it is followed by an unstressed nucleus and preceded by an //n// that is..preceded by a stressed nucleus. b. Linguistics. The main or central word or words in a compound, phrase, or sentence; (also) = kernel n.¹ 8b(a). ΘΚΠ the mind > language > linguistics > study of grammar > morphology > morpheme > [noun] > stem or base theme1530 thema1615 crude form1805 base1836 stem1851 base form1864 word base1865 kernel1894 stem-form1928 nucleus1932 base word1935 the mind > language > linguistics > study of grammar > syntax or word order > syntactic unit or constituent > [noun] > minimal sequence nucleus1932 minimal (also minimum) terminable unit1965 T-unit1965 1932 W. L. Graff Lang. & Langs. v. 202 Subiya, a language of South Africa, classifies all things into twenty-one categories regularly represented by twenty-one different propositions. The indication of one of these categories constitutes the nucleus of the sentence to which everything else is to be subordinated. 1934 R. C. Priebsch & W. E. Collinson German Lang. ii. v. 258 Composite words consisting of a determinant word (Bestimmungswort) and a nucleus (Grundwort). The determinant may be an adjective..or a substantive. 1949 E. A. Nida Morphol. (ed. 2) iv. 83 The nucleus of a morphological construction consists of (1) a root or (2) a combination of roots... The nonnucleus is made up of nonroots. In the construction boyishness the element boy is the nucleus and -ishness constitutes the nonnucleus. 1961 R. B. Long Sentence & its Parts 497 Nucleuses, minimal sequences made up of subjects, predicators, and complements, or of such of these as occur... In come in! the nucleus is made up of the predicator come and the complement in. 1968 J. Lyons Introd. Theoret. Linguistics viii. 334 The subject and the predicate together form the nucleus of the sentence. II. General uses. 13. a. A person or group of people that provides or forms the central or originating core, heart, or foundation of a community, society, organization, etc. nucleus crew n. British Navy (now rare) the essential members of a ship's crew; a skeleton crew. ΚΠ 1753 T. Smollett Ferdinand Count Fathom I. xxxv. 258 Fathom, as usual, formed the nucleus or kernel of the beau monde; and the season soon became so crouded, that many people of fashion were obliged to quit the place for want of lodging. 1798 W. Hutton Life 120 About 700 individuals..were the nucleus of his colony of Georgia. 1853 C. Merivale Fall Rom. Republic v. 150 The few hundred families, which formed the original nucleus of her citizenship. 1868 J. H. Blunt Reformation Church of Eng. II. 95 A Protestant party which crystallized around the nucleus of antisacerdotalists. 1904 Westm. Gaz. 10 Dec. 11/1 They will have a nucleus crew of two-fifths of their war complement. 1914 C. F. Tweney Dict. Naval & Mil. Terms 163 Nucleus crew, the essential members of a ship's crew, such as petty officers, gunners, etc., the crew being raised to full strength in case of mobilisation. 1922 Morning Post 29 Dec. 8/2 A nucleus is a [Communist] Party organisation working inside an organisation. 1965 M. Morse Unattached i. 57 The mood of each rehearsal..depended very much on the attitude of the nucleus group. 1987 Christian Aid News Jan. 7 9/1 Those units were eventually to form the nucleus of the new Sudan People's Liberation Army (SPLA). b. Of immaterial things: that which is most central or fundamental; a central point, idea, etc., from or around which something can develop or has developed; (of a written or oral composition) the material on which the complete work was based. ΚΠ 1820 Edinb. Rev. May 314 The nucleus of fine thought is there. 1835 C. Thirlwall Hist. Greece I. vi. 248 They manifestly formed the basis or nucleus of the epic cycle. 1876 ‘G. Eliot’ Daniel Deronda IV. vii. li. 26 Each nucleus of pain or pleasure. 1887 Dict. National Biogr. at W. Christian The original nucleus of the ballad seems to have been composed shortly after Christian's death. 1890 W. James Princ. Psychol. I. 298 Let us settle for ourselves as definitely as we can, just how this central nucleus of the Self may feel, no matter whether it be a spiritual substance or only a delusive word. 1905 E. Wharton House of Mirth i. iii. 53 Lily's beauty..was the last asset in their fortunes, the nucleus around which their life was to be rebuilt. 1927 Amer. Mercury Feb. 232/1 A brief examination of his system of selection will reveal the nucleus of the fiasco. 1992 C. F. Lummis & R. F. Gish Pueblo Indian Folk-stories xvii. 117 (note) We may always depend upon it that there is a nucleus of truth in all these folk-myths. c. A place, building, etc., which constitutes a centre around which development has taken or can take place; (also) a place which provides the focus for a particular activity. ΚΠ 1839 G. P. R. James Louis XIV I. 266 A town was the nucleus round which a province, a kingdom, an empire was gathered together. 1865 W. E. H. Lecky Hist. Rationalism II. vi. 261 When a monastery was planted, it soon became the nucleus around which the inhabitants of the neighbourhood clustered. 1872 S. W. Baker Nile Tributaries Abyssinia (new ed.) v. 73 It formed a nucleus for the general gathering of the people with their flocks. 1896 Dict. National Biogr. at R. Le Poor The greater part of his work, recently identified, still remains as the nucleus of the present building. 1910 Encycl. Brit. I. 25/2 The nucleus of the estate was a small farm of 100 acres, called Cartleyhole. 1947 W. Lowrie Art in Early Church iii. 48 The name Lucina..is associated with the burial place of St. Paul and with the earliest nucleus of the cemetery of Callistus. 1984 J. Morris Journeys (1985) 129 The tight, tough island quarter called Garnla Stan, Old Town, the original nucleus of the city. d. A collection or group of things which forms the core or foundation for a larger collection or group; a sum of money which forms the basis of a larger amount. ΚΠ 1857 T. Hughes Tom Brown's School Days ii. iv. 309 The kestrel's eggs..formed the nucleus of Arthur's collection. 1863 C. Reade Hard Cash II. xi. 139 With your abilities and experience five thousand pounds may yet be the nucleus of a fortune. 1870 J. H. Bennet Winter & Spring Mediterranean viii. 221 There is already a very fair collection of modern books in hand, as the nucleus of a library. 1899 J. Sartain Reminisc. Very Old Man i. 17 Sir Hans Sloane, whose collection became the nucleus of the present fine assemblage of curious and beautiful objects housed in the British Museum. 1921 A. R. Williams Through Russ. Revol. v. 84 The club boasted a much-used magazine room, the nucleus of a library, and an excellent illustrated weekly. 1940 L. P. Stebbins Enchanted Wanderer xix. 286 There had been a residue of money and it was proposed to make this the nucleus of a fund for a monument. 1998 M. Jacobs Budapest 118 The present light and airy setting..makes for an excellent, clear display of the old Hungarian instruments that form the nucleus of the collections. This entry has been updated (OED Third Edition, December 2003; most recently modified version published online June 2022). † nucleusv. Origin: Formed within English, by conversion. Etymon: nucleus n. Etymology: < nucleus n. Obsolete. rare. intransitive and transitive. To form a nucleus; to group together into a nucleus. ΘΚΠ the world > space > relative position > central condition or position > mark or be the centre of [verb (transitive)] > make into a nucleus or node nucleus1826 nucleate1856 nodalize1915 1826 S. T. Coleridge Coll. Lett. (1971) VI. 655 An erysipelatous affection..which a too free use of my Nails..has nucleus'd with an orifice that shews no disposition to heal. 1899 R. Kipling Stalky & Co. 252 They'd withdrawn all the troops they could, but I nucleused about forty Pathans. This entry has been updated (OED Third Edition, December 2003; most recently modified version published online June 2021). < n.1668v.1826
随便看	convallamarin convallaretin convallarin convally convanesce convanescible convanescible edge convanquish convect convected convecting convection convection cell convection current convection oven convectional convections convective convectively convector convector heater convectors convects convell convelled

nucleusn.

† nucleusv.