| 单词 | emission line |
| 释义 | > as lemmasemission line emission line n. (in spectroscopy) a bright line in the spectrum of electromagnetic radiation coming from a source or substance, caused by emission at a particular wavelength; cf. emission spectrum n. at Compounds.Analysis of the emission spectrum of a given source (e.g. a star) can be used to determine the chemical composition of that source, as every atom and molecule emits electromagnetic radiation at a characteristic set of wavelengths whenever it returns to a lower-energy configuration from a higher-energy one. Cf. absorption line n. at absorption n. Compounds 2. ΚΠ 1878 Nature 18 Apr. 499/1 An absorption-line is seen, with a wave-length of about 5,730, which is more refrangible than the yellow double emission line of potassium. 1922 A. D. Udden tr. N. Bohr Theory of Spectra iii. iv. 118 Emission lines of the X-ray spectra [are] due to transitions between the stationary states corresponding to these energy levels. 2012 R. B. Thompson & B. F. Thompson Illustr. Guide Home Forensic Sci. Exper. 71/1 Iron is present in some soils..in amounts large enough to provide prominent emission lines. < as lemmas |
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