Effects of temperature and pressure on the transformation rate from air bubbles to air-hydrate crystals in ice sheets
Effects of temperature and pressure on the transformation rate from air bubbles to air-hydrate crystals in ice sheets
复制标题
温度和压力对冰盖中气泡向空气水合物晶体转化速率的影响
DOI：
10.3189/1994aog20-1-143-147
复制
发表时间：
1994
影响因子：
2.9
通讯作者：
V. Lipenkov
中科院分区：
文献类型：
--
作者：
T. Uchida;T. Hondoh;S. Mae;P. Duval;V. Lipenkov
对深厚冰盖中空气水合物晶体的形成和生长过程进行了实验研究，以确定气泡向空气水合物晶体的转变过程。显微镜观察显示，这种转变始于气泡和冰的交界处。沿边界发生了较快的相变，随后相变以较低的速度向气泡中心推进。各转化率均随压力和温度的升高而增加。一次相变的激活能约为0.52 eV，后续相变的激活能约为0.90 eV。这些结果表明，决定转化过程的速率主要是水分子对转化部位的补充。对深冰盖中气泡转变为空气水合物晶体的周期的估计表明，它大约是过渡带时间周期的千分之一，在过渡带，空气水合物和气泡都存在。
Experimental investigations on the formation and growth processes of air-hydrate crystals were carried out to determine the transformation process of air bubbles into air-hydrate crystals in deep ice sheets. The microscopic observations revealed that the transformation began at the boundary between a bubble and ice. Faster transformation occurred along the boundary and, subsequently, the transformation progressed towards the center of the bubble at a lower rate. Each transformation rate increased with pressure and also with temperature. The activation energy of the transformation was about 0.52 eV for the primary transformation process and about 0.90 eV for subsequent processes. These results indicate that the rate determining the process of transformation is mainly supplementation of water molecules to the transformation site. An estimation of the transformation period of an air bubble into an air-hydrate crystal in a deep ice sheet reveals that it is about one thousandth of the time period of the transition zone, where both air-hydrates and air bubbles exist