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自70年代以来,对湖泊沉积物中核试验散落核素的研究已成为研究现代湖泊沉积过程和沉积年代及沉积速率的一个重要方面,本文通过对分别采自云南省滇池、剑湖的两个沉积孔柱中~(137)Cs和~(241)Am蓄积分布的研究,测定了它们60、70年代以来的沉积速率分别是42.1和28.7mg/(cm~2·a)。研究发现,虽然~(241)Am的含量远低于~(137)Cs,但~(241)Am具有沉积后迁移能力较小,半衰期长等特点,因而随着时间的推移,在未来湖泊现代沉积作用的研究中将会显示出越来越重要的作用。
Since the 1970s, the study on the nuclear test of scattered nuclides in lake sediments has become an important aspect to study the sedimentation process and depositional age of modern lakes and sedimentation rates. In this paper, two sediments collected from Dianchi and Jian’en in Yunnan Province, The accumulation distribution of ~ (137) Cs and ~ (241) Am in the pore column was measured and the deposition rates since 60s and 70s were 42.1 and 28.7 mg / (cm ~ 2 · a), respectively. The results show that although the content of ~ (241) Am is much lower than that of ~ (137) Cs, ~ (241) Am has the characteristics of small migration capacity and long half-life after sedimentation. Therefore, with the lapse of time, Deposition studies will show an increasingly important role.