pionn.

Brit.

/ˈpʌɪɒn/, U.S.

/ˈpaɪˌɑn/

Origin: Formed within English, by derivation. Etymons: pi n.¹, -on suffix¹, pi-meson n.

Etymology: < pi n.¹ + -on suffix¹, as alteration of pi-meson n. Compare muon n.

Particle Physics.

Any of a group of mesons that have masses of approx. 140 MeV (270 times that of the electron), zero spin, zero hypercharge, and isospin of 1, on decaying usually produce a muon and a neutrino (in the case of charged pions) or two photons (in the case of the neutral pion), and are constituents of cosmic rays at the earth's surface; a pi-meson.Pions are now regarded as composed of a quark and an antiquark.

ΘΚΠ

the world > matter > physics > atomic physics > particle physics > particle participating in strong interaction > meson > [noun] > pion

pi-meson1947

pion1951

1951 Sci. News 21 21 The mass of π-mesons, or pions as they are called in short,..appears to be in the neighbourhood of 276 times that of the electron.

1968 M. S. Livingston Particle Physics vi. 124 The neutral pion π° can be formed through the charge-exchange process π⁻ + p → n + π° following capture of the π⁻ in a Bohr orbit.

1988 T. Ferris Coming of Age in Milky Way (1989) iii. xvi. 321 Musset..discerned a kink in the recorded path of a particle that gave away its identity as a pion rather than a muon.

2002 F. Close et al. Particle Odyssey v. 73 (caption) The decay of a positive pion is captured by a device called a streamer chamber.

This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2022).

† pionv.

Origin: Either (i) a borrowing from French. Or (ii) formed within English, by clipping or shortening. Etymons: French pionner ; pioneer n.

Etymology: Either < Middle French pionner to dig, to excavate (c1380; < peon , pion foot soldier: see pawn n.¹), or < pion- (in pioneer n.). Compare earlier pioning n., pioning adj., pioned adj.

Obsolete. rare.

intransitive. To dig, excavate; to do the work of a pioneer.

ΘΚΠ

society > occupation and work > industry > earth-moving, etc. > [verb (intransitive)] > dig or excavate

gravea1000

delvec1000

wrootc1325

minec1330

gruba1350

sinkc1358

undermine1382

diga1387

spit1393

to pick upc1400

holk1513

graff1532

pion1643

excavate1843

throw1843

crow1853

spade1869

1643 T. Goodwin Vanity of Thoughts 27 He'll digge and fall a pioning, with his thoughts, his engins, in the night.

This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2020).

单词	pion
释义	pionn. Brit. /ˈpʌɪɒn/, U.S. /ˈpaɪˌɑn/ Origin: Formed within English, by derivation. Etymons: pi n.¹, -on suffix¹, pi-meson n. Etymology: < pi n.¹ + -on suffix¹, as alteration of pi-meson n. Compare muon n. Particle Physics. Any of a group of mesons that have masses of approx. 140 MeV (270 times that of the electron), zero spin, zero hypercharge, and isospin of 1, on decaying usually produce a muon and a neutrino (in the case of charged pions) or two photons (in the case of the neutral pion), and are constituents of cosmic rays at the earth's surface; a pi-meson.Pions are now regarded as composed of a quark and an antiquark. ΘΚΠ the world > matter > physics > atomic physics > particle physics > particle participating in strong interaction > meson > [noun] > pion pi-meson1947 pion1951 1951 Sci. News 21 21 The mass of π-mesons, or pions as they are called in short,..appears to be in the neighbourhood of 276 times that of the electron. 1968 M. S. Livingston Particle Physics vi. 124 The neutral pion π° can be formed through the charge-exchange process π⁻ + p → n + π° following capture of the π⁻ in a Bohr orbit. 1988 T. Ferris Coming of Age in Milky Way (1989) iii. xvi. 321 Musset..discerned a kink in the recorded path of a particle that gave away its identity as a pion rather than a muon. 2002 F. Close et al. Particle Odyssey v. 73 (caption) The decay of a positive pion is captured by a device called a streamer chamber. This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2022). † pionv. Origin: Either (i) a borrowing from French. Or (ii) formed within English, by clipping or shortening. Etymons: French pionner ; pioneer n. Etymology: Either < Middle French pionner to dig, to excavate (c1380; < peon , pion foot soldier: see pawn n.¹), or < pion- (in pioneer n.). Compare earlier pioning n., pioning adj., pioned adj. Obsolete. rare. intransitive. To dig, excavate; to do the work of a pioneer. ΘΚΠ society > occupation and work > industry > earth-moving, etc. > [verb (intransitive)] > dig or excavate gravea1000 delvec1000 wrootc1325 minec1330 gruba1350 sinkc1358 undermine1382 diga1387 spit1393 to pick upc1400 holk1513 graff1532 pion1643 excavate1843 throw1843 crow1853 spade1869 1643 T. Goodwin Vanity of Thoughts 27 He'll digge and fall a pioning, with his thoughts, his engins, in the night. This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2020). < n.1951v.1643
随便看	peculia peculiar peculiar domestic institution peculiar institution peculiar metre peculiar nation peculiar people peculiar race peculiar to peculiar-looking peculiar-shaped peculiar-tasting peculiarise peculiarised peculiarises peculiarising peculiarism peculiarities peculiarity peculiarize peculiarized peculiarizes peculiarizing peculiarlooking peculiarly