南极普里兹湾海域铀系同位素的分布

DISTRIBUTION OF URANIUM-SERIES ISOTOPES IN THE PRYDZ BAY, ANTARCTICA

本文报道了南极普里兹湾海域U、2 2 6Ra、2 1 0 Pb、2 1 0 Po的分布以及2 34U/2 38U和2 1 0 Po/2 1 0 Pb放射性比值。研究结果表明 ,该海域表层水中的铀同位素分布基本均匀 ,铀含量范围为1 3 2 8— 1 4 2 0 μmol·m- 3,平均值为 ( 1 3.82± 0 .2 9) μmol·m- 3,2 34U/2 38U平均放射性比值为1 1 4± 0 0 3。铀含量与盐度之间存在良好的相关性 ,其相关系数达 0 895。该海域溶解态2 2 6Ra比活度范围为 1 37— 1 78Bq·m- 3,平均值为 1 5 5Bq·m- 3;颗粒态 2 2 6Ra比活度范围为0 0 0 6— 0 0 35Bq·m- 3,平均值为 0 0 1 5Bq·m- 3;2 1 0 Po比活度 0 80— 1 5 2Bq·m- 3,平均 1 1 4Bq·m- 3;2 1 0 Pb比活度 1 34— 2 1 5Bq·m- 3,平均 1 66Bq·m- 3;2 1 0 Po/2 1 0 Pb的放射性比值0 5 5— 0 84,平均 0 69。并对2 1 0 Po和2 1 0 Pb的不平衡作了讨论。还研究了 1个站位溶解态和颗粒态2 2 6Ra、2 1 0 Pb的深度分布及2 1 0

The distributions of 234U, 238U, 226Ra, 210Pb and 210Po in the Prydz Bay, Antarctic, 234U/ 238U and 210Po/ 210Pb activity ratios are reported. The results show that the concentration of uranium in surface water is varies from 13.28-14.20 μmol·m -3, with an average of (13.82±0.29) μmol·m -3. The mean values of ( 234U/ 238U) A.R. is 1.14±0.03. Uranium concentration-salinity relation is, U=0.443S-0.988 (r=0.895). The dissolved 226Ra varied from 1.37 to 1.78 Bq·m -3 with an average of 1.55 Bq·m -3. Particulate 226Ra in 5 surface water samples of studied areas range from 0.006-0.035 Bq·m -3 with an average of 0.015 Bq·m -3. The concentration ranges are 0.80-1.52 Bq·m -3 with an average of 1.14 Bq·m -3 for dissolved 210Po, and 1.34-2.15 Bq·m -3 with an average of 1.66 Bq·m -3 for dissolved 210Pb. The 210Po/ 210Pb activity ratios are 0.55-0.84 with a mean ratio of 0.69. The extent of 210Po/ 210Pb disequilibria is discussed. The vertical distributions of dissolved and particulate 210Pb, 226Ra in six layers from upper 200 m depths of ST station and Portioning between dissolved and particulate phases are presented.