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伴随着20世纪50年代及60年代初大规模的大气层核试验活动,原本稳定的大气中CO2的14C含量迅速升高,并通过生物地球化学循环渗透到整个生物圈,自1963年《部分禁止核试验条约》签订后,大气中CO2的14C含量开始迅速减少,其速度却远超过了14C自身的衰变速度,树轮和珊瑚等环境信息载体的14C记录都体现了这一迅速增长而后又衰减的过程。近50年对全球大气中CO2的14C含量的数据采集和发布,使人们发现了14C含量作为现代时间标尺的可行性。介绍了现代核试验14C在法医学鉴定中新的应用方向——根据牙釉质的14C含量确定不明身份死者的出生年代。对于无法判定样品形成于大气14C含量峰值前后的问题,尝试应用同一个人釉质完成时间不同的两颗牙齿的14C含量比较,来予以解决。实验数据结果与真实记录之间的绝对误差为1.4a,优于以前骨龄和牙齿磨损度等传统的法医鉴定方法。
Accompanied by large-scale atmospheric nuclear testing activities in the 1950s and early 1960s, the 14C content of the originally stable atmospheric CO2 rapidly increased and penetrated the entire biosphere through biogeochemical cycles. Since the partial banning of nuclear tests After the Treaty was signed, the 14C content of atmospheric CO2 began to decrease rapidly, but its speed far exceeded the decay rate of 14C itself. The 14C records of environmental information carriers such as tree rings and corals embody this process of rapid growth and then decay . The data collection and release of 14C content of CO2 in the global atmosphere in the past 50 years has led to the discovery of the 14C content as a modern time scale. The new application of modern nuclear test 14C in the forensic identification is introduced. The birth date of the unidentified dead is determined according to the 14C content of enamel. For the determination of the sample before and after the formation of the peak 14C content in the atmosphere, try to use the same human enamel finish time 14C content of two different teeth to be resolved. The absolute error between the experimental data and the real record is 1.4a, which is superior to traditional forensic methods such as previous bone age and tooth wear.