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    請使用永久網址來引用或連結此文件: https://ir.lib.ncu.edu.tw/handle/987654321/101162


    題名: Irradiation of pyrimidine in pure H2O ice with high-energy ultraviolet photons
    作者: 葉永烜;Nuevo, Michel;Chen, Yu-Jung;Hu, Wei-Jie;Qiu, Jun-Ming;Wu, Shang-Ruei;Fung, Hok-Sum;Chu, Ching-Chi;Yih, Tai-Sone;Ip, Wing-Huen;Wu, C.-Y. Robert
    貢獻者: 理學院天文研究所
    關鍵詞: Chromatography, High Pressure Liquid;Gas Chromatography-Mass Spectrometry;Half-Life;Ice;Photons;Pyrimidines - radiation effects;Spectrophotometry, Infrared;Synchrotrons;Ultraviolet Rays
    日期: 2014-02-01
    上傳時間: 2026-04-21 14:25:45 (UTC+8)
    出版者: Mary Ann Liebert Inc.;Los Angeles, CA: SAGE Publications
    摘要: 摘要: The detection of nucleobases, the informational subunits of DNA and RNA, in several meteorites suggests that these compounds of biological interest were formed via astrophysical, abiotic processes. This hypothesis is in agreement with recent laboratory studies of irradiation of pyrimidine in H2O-rich ices with vacuum UV photons emitted by an H2-discharge lamp in the 6.9–11.3 eV (110–180 nm) range at low temperature, shown to lead to the abiotic formation of several compounds including the nucleobases uracil, cytosine, and thymine. In this work, we irradiated H2O:pyrimidine ice mixtures under astrophysically relevant conditions (14 K, ≤10−9 torr) with high-energy UV photons provided by a synchrotron source in three different ranges: the 0th order light (4.1–49.6 eV, 25–300 nm), the He i line (21.2 eV, 58.4 nm), and the He ii line (40.8 eV, 30.4 nm). The photodestruction of pyrimidine was monitored with IR spectroscopy, and the samples recovered at room temperature were analyzed with liquid and gas chromatographies. Uracil and its precursor 4(3H)-pyrimidone were found in all samples, with absolute and relative abundances varying significantly from one sample to another. These results support a scenario in which compounds of biological interest can be formed and survive in environments subjected to high-energy UV radiation fields. Key Words: Pyrimidine—Nucleobases—Interstellar ices—Cometary ices—High-energy photons—Molecular processes—Prebiotic chemistry. Astrobiology 14, 119–131.
    其他題名: Astrobiology
    出版者: Los Angeles, CA: SAGE Publications
    出版日期: 2014-02
    出處: Astrobiology, 2014-02, Vol.14 (2), p.119-131
    版權: Copyright 2014, Mary Ann Liebert, Inc.
    版權: Copyright 2014, Mary Ann Liebert, Inc. 2014
    識別號: ISSN: 1531-1074
    識別號: ISSN: 1557-8070
    識別號: EISSN: 1557-8070
    識別號: DOI: 10.1089/ast.2013.1093
    識別號: PMID: 24512484
    顯示於類別:[天文研究所] 期刊論文

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