【摘要】 本文着重讨论了已往大气中¹⁴C浓度的长期、中期和短期变化,以及这些变化与地球磁场的变化、人为活动因素、太阳活动和气候变化等的密切关系。已知年代树木年轮的¹⁴C含量的测定,为研究大气¹⁴C浓度的变化及其原因提供了可靠的依据。更多还原

【Abstract】 In this paper, we discuss the long, medium and shortterm changes of 14C concentration in the atmosphere in the past, and their relations with the fluctuations of the earth’s magnetic dipole moment, human activities, solar activities and the change of climate. The measurements of the variations of 14C contents in dated tree rings have provided valuable information on these changes.更多还原