摘要
研究了1994年8－9月南海东北部表层海水中228Ra的分布特征。采用Mn－纤维富集海水中的Ra同位素，通过其子体228Ac的β计数法来测量228Ra。表层海水中228Ra的放射性比活度从2．48Bq·m－3变化到4.47Bq·m－3，平均值为3.24Bq·m－3。228Ra的水平分布表现为调查海区东北部比活度较高，这与该航次的226Ra的分布特征相一致。根据各断面的228Ra放射性比活度与离岸距离之间的负相关关系，计算了它们所对应的水平涡动扩散系数，并讨论海域的地貌特征对228Ra比活度分布的影响。这些研究结果对表层水体的混合、交换，尤其是可溶性污染物的迁移、扩散以及海域的自净作用的研究都具有实际意义。
The distribution of 228 Ra in the surface water of the northeastern South China Sea during 1994 cruise was studied. Mn-fibre was used to concentrate radium isotopes from the sea water and are Ra activity was measured through β-counting of 228Ac. 228Ra specific activity in the surface water varied from 2.48 to 4.47 Bq' m-3,averaging 3.24 Bq' m-3. The horizontal distribution of 228 Ra showed that greater specific activity appeared in the northeastern part of this studied area, which is similar to that of 226 Ra during this cruise. Based on the exponential correlation between 228 Raspecific activity and the distance away from the shoreline in a section, the corresponded horizontal eddy diffusion coefficient was calculated' These research results undoubtedly are practically significant for the future studies on the mixing and exchange of surface water, the transportation and diffusion of dissoluble pollutants as well as the self-cleaning capacity of this sea area.
出处
《热带海洋》
CSCD
1997年第2期67-74,共8页
基金
国家自然科学基金!49456001
高等学校博士学科点专项科研基金
关键词
南海
表层水体
水平涡动扩散
同位素示踪
镭228
Northeastern South China Sea,^(228) Ra, horizontal eddy diffusion, surface water
