Ancilotto F, Chiarotti G L, Scandolo S, Tosatti E
Dipartimento di Fisica "G. Galilei," Universitá di Padova, Via Marzolo 8, I-35131 Padova, Italy.
Science. 1997 Feb 28;275(5304):1288-90. doi: 10.1126/science.275.5304.1288.
Constant-pressure, first-principles molecular dynamic simulations were used to investigate the behavior of methane at high pressure and temperature. Contrary to the current interpretation of shock-wave experiments, the simulations suggest that, below 100 gigapascals, methane dissociates into a mixture of hydrocarbons, and it separates into hydrogen and carbon only above 300 gigapascals. The simulation conditions (100 to 300 gigapascals; 4000 to 5000 kelvin) were chosen to follow the isentrope in the middle ice layers of Neptune and Uranus. Implications on the physics of these planets are discussed.
采用恒压第一性原理分子动力学模拟研究了甲烷在高压和高温下的行为。与当前对冲击波实验的解释相反，模拟结果表明，在100吉帕斯卡以下，甲烷分解为碳氢化合物混合物，只有在300吉帕斯卡以上才会分离成氢和碳。选择模拟条件（100至300吉帕斯卡；4000至5000开尔文）以跟踪海王星和天王星中间冰层中的等熵线。讨论了这些结果对这些行星物理学的影响。
