Pfund seriesn.

Brit.

/ˈfʊnt ˌsɪərɪz/,

/ˈfʊnd ˌsɪərɪz/, U.S.

/ˈfənd ˌsɪriz/

Origin: From a proper name, combined with an English element; modelled on a German lexical item. Etymons: proper name Pfund , series n.

Etymology: < the name of A. Herman Pfund (1879–1949), U.S. physicist, who discovered the phenomena + series n., after German Pfund-Serie (A. Sommerfeld Atombau u. Spektrallinien (ed. 5, 1931) I. ii. 80).

Physics.

A series of lines in the infrared part of the spectrum of atomic hydrogen, with wave numbers represented by R(1/5² − 1/m²) (where R is the Rydberg constant and m = 6, 7,…), of which the first line has a wavelength of 7.46 micrometres and the series limit is at 2.28 micrometres.

ΘΚΠ

the world > matter > physics > atomic physics > decomposition of light, spectrum > [noun] > component of wave number > formula giving wave numbers > constant appearing in > numbers calculated with

Pfund series1934

1934 H. H. L. A. Brose tr. A. J. W. Sommerfeld Atomic Struct. & Spectral Lines (ed. 3) ii. 73 A. H. Pfund found an infra-red line belonging to hydrogen at λ = 7·40μ, which is the first member of a ‘Pfund series’ and corresponds to n = 5, m = 6.

1970 D. W. Tenquist et al. Univ. Optics II. ii. 43 Lines in the infra-red part of the spectrum are caused by transitions terminating at n = 3 (Paschen series), n = 4 (Brackett series) and n = 5 (Pfund series).

1996 Astrophysical Jrnl. 461 299/1 The prominent features in this rich spectrum include emission from the Brackett and Pfund series of hydrogen.

This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022).

单词	pfund series
释义	Pfund seriesn. Brit. /ˈfʊnt ˌsɪərɪz/, /ˈfʊnd ˌsɪərɪz/, U.S. /ˈfənd ˌsɪriz/ Origin: From a proper name, combined with an English element; modelled on a German lexical item. Etymons: proper name Pfund , series n. Etymology: < the name of A. Herman Pfund (1879–1949), U.S. physicist, who discovered the phenomena + series n., after German Pfund-Serie (A. Sommerfeld Atombau u. Spektrallinien (ed. 5, 1931) I. ii. 80). Physics. A series of lines in the infrared part of the spectrum of atomic hydrogen, with wave numbers represented by R(1/5² − 1/m²) (where R is the Rydberg constant and m = 6, 7,…), of which the first line has a wavelength of 7.46 micrometres and the series limit is at 2.28 micrometres. ΘΚΠ the world > matter > physics > atomic physics > decomposition of light, spectrum > [noun] > component of wave number > formula giving wave numbers > constant appearing in > numbers calculated with Pfund series1934 1934 H. H. L. A. Brose tr. A. J. W. Sommerfeld Atomic Struct. & Spectral Lines (ed. 3) ii. 73 A. H. Pfund found an infra-red line belonging to hydrogen at λ = 7·40μ, which is the first member of a ‘Pfund series’ and corresponds to n = 5, m = 6. 1970 D. W. Tenquist et al. Univ. Optics II. ii. 43 Lines in the infra-red part of the spectrum are caused by transitions terminating at n = 3 (Paschen series), n = 4 (Brackett series) and n = 5 (Pfund series). 1996 Astrophysical Jrnl. 461 299/1 The prominent features in this rich spectrum include emission from the Brackett and Pfund series of hydrogen. This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022). < n.1934
随便看	key change key chord key cipher key clock key code key colour key course key cutter key deer key desk key down key drawing key drop key escrow key field key file key fob key fruit key grip key groove key gun key hammer key in key instrument key into