A sea-water sample which comprises the international standard for D:H and 18O:16O ratios. Differences in isotopic composition are expressed as parts per mille (‰) deviations from the isotopic composition of this standard.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。