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Hokkaido University Collection of Scholarly and Academic Papers >
Institute of Low Temperature Science >
低温科学 = Low Temperature Science >
第64巻 >
Ｘ線回折によるガスハイドレートの高圧相変化と地球惑星科学的意義
| Title: | Ｘ線回折によるガスハイドレートの高圧相変化と地球惑星科学的意義 |
| Other Titles: | In-situ X-ray diffraction study on phase changes of gas hydrates and the significance for geological and planetary sciences |
| Authors: | 平井, 寿子1 Browse this author →KAKEN DB | | 山本, 佳孝2 Browse this author →KAKEN DB | | 川村, 太郎3 Browse this author |
| Authors(alt): | Hirai, Hisako1 | | Yamamoto, Yoshitaka2 | | Kawamura, Tarou3 |
| Issue Date: | 22-Mar-2006 |
| Publisher: | 北海道大学低温科学研究所 |
| Journal Title: | 低温科学 |
| Journal Title(alt): | Low temperature science |
| Volume: | 64 |
| Start Page: | 191 |
| End Page: | 197 |
| Abstract: | ガスハイドレートは，従来，内包するゲストサイズにより構造が選択されると考えられていたが，近
年ダイヤモンドアンビルを用いた高圧Ｘ線回折実験によって新たな相の存在や多様な相変化が明らか
となった．本稿では水素からキセノンまでのガスハイドレートに対し，ゲストサイズと圧力とをパラ
メータとする相変化を概観する．また，メタンハイドレートの特異的な高圧安定性を基に，海王星や
タイタンなどの氷惑星・衛星における存在の可能性を検討する． | | Recent high-pressure studies on gas hydrates, including methane hydrate, have accumulated to the extent that we now have a better understanding of the phase changes in gas hydrates. A feature of phase changes in terms of pressure and guest size was summarised earlier in this paper. Gas hydrates with a guest size from argon to methane eventually take a common filled ice Ih structure, although they have different initial and intermediate structures. In the latter part, retention by the filled ice Ih structure of methane hydrate up to 42 GPa is described. In-situ x-ray diffractometry and optical observation revealed the existence of the filled ice structure with as volume change of 40% and large anisotropic compressibility. Symmetrization of the hydrogen bonds in water molecules forming the fundamental structure was suggested to occur. The meanings for geological and planetary sciences of the phase changes and the retention of a very high pressure of methane hydrate are also discussed. |
| Description: | 3章 クラスレートハイドレート研究のフロンティア |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/8333 |
| Appears in Collections: | 低温科学 = Low Temperature Science > 第64巻
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