排序方式： 共有15条查询结果，搜索用时 15 毫秒
1.
2.
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 Pb在两相中的分配 相似文献
3.
Oxygen isotopic composition and its application to the study of tracing oceanographical process in Bering Sea and Chukchi Sea 
下载免费PDF全文
下载免费PDF全文 In this paper, the 18 O distribution of surface water from the central sea areas of the Bering Sea and the Chukchi Sea was studied. The δ 18 O value of surface water from the Bering Sea is averagely -0.5‰; the δ 18 O contents of the Chukchi Sea are distributionally lower in northeast and higher in southwest; the δ 18 O value at the margin of Canadian Basin is -2.8‰, and averagely -0.8‰ in the southern area of the Chukchi Sea. The δ 18 O vertical distribution in some deep water stations from the Chukchi Sea and the Bering Sea is also studied. In the southern margin of Canadian Basin, the δ 18 O value is -2‰ -3‰ for surface layer and rises to 0 at 100 m depth layer. In the Bering Sea, the δ 18 O is about -0.5‰ for surface layer and increases to 0 at the depth of 300 m. The NO tracer can reflect obviously three water masses vertically distributed in the central Bering Sea: the upper Bering water mass, the middle Bering water mass and the deep Pacific water mass. The distributive ranges of NO and temperature for the various water masses are T<7℃, NO>780 μmol/dm 3 and T≥7℃, NO>650 μmol/dm 3 for upper Bering water mass, T<4℃, 550相似文献
4.
5.
世界大洋表层水中的210Pb 总被引：2，自引：0，他引：2
本工作获得了西太平洋,东印度洋和南大西洋15个站位表层水中的溶解态210Pb和颗粒态210Pb的浓度.溶解态210Pb的浓度范围为西太平洋0.71～3.80Bq/m3;东印度洋0.42～2.15Bq/m3;南大西洋0.97～1.78Bq/m3.210Pb最大值3.80Bq/m3是在27°18′N,125°40′E(北太平洋)测得的,而最小值0.42Bq/m3是在远离澳大利亚西岸的25°18′S,111°38′E(东印度洋)测得的.在26°56′S,166°07′E(南太平洋)观测到颗粒态210Pb浓度的最大值0.35Bq/m3,而在东南印度洋颗粒态210Pb的浓度都小于0.03Bq/m3.表层水中溶解态210Pb含量一般呈现出地理性变化,其随纬度的变化与文献报道的结果很相符. 相似文献
6.
本文提供了1989～1991年广东近岸表层水中~(90)Sr和~(137)Cs含量的分析结果。在调查海区,~(90)Sr含量为2.31～3.75mBq/L,平均值为3.21±0.45mBq/L。~(137)Cs含量为2.10～4.49mBq/L,平均值为3.47±0.89mBq/L。~(137)Cs/~(90)Sr放射性的比值为0.63～1.69,平均值为1.11±0.35。调查结果表明,近三年来未发现广东近岸海域有明显的人工放射性污染。目前广东近岸海水中的~(90)Sr和~(137)Cs主要仍是以往核试验所产生的放射性落下灰残余。 相似文献
7.
The methods of ion exchange-elcctrodcposition, ion exchange-precipitation for source-making, and for determining 65Zn in marine environment have been studied in detail. The chemical and radiochemical yields are 90% for organism and sediment, and 85% for seawater. They have good repeatability with a precision of 3%. The decontamination factors for radioactive nuclides are larger than 103. The preconcentration of seawater and the electrode position for source-making are significantly improved and can be used on thin and even source-measucing, applicable to low background β counting. 相似文献
8.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ18Ｏｉｎｍａｒｉｎｅｅｎｖｉｒｏｎｍｅｎｔｐｌａｙｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｏｃｅａｎｏｇｒａｐｈｉｃａｌｓｔｕｄｙ .Ａｓａｓｔａｂｌｅｉｓｏｔｏｐｅｏｆｏｘｙｇｅｎ ,18ＯｔｏｇｅｔｈｅｒｗｉｔｈｈｙｄｒｏｇｅｎａｔｏｍｓｃｏｎｓｔｉｔｕｔｅｓｗａｔｅｒｍｏｌｅｃｕｌｅＨ218ＯａｎｄｍｏｖｅｓｗｉｔｈａｌａｒｇｅａｍｏｕｎｔｏｆＨ2 Ｏｍｏｌｅｃｕｌｅｓｉｎｓｅａｗａｔｅｒ.Ｓｏｔｈａｔδ18Ｏｂｅｃｏｍｅｓａｎｉｄｅａｌｔｒａｃｅｒｆｏｒｔｈｅｍｏｖｅｍｅｎｔｏ… 相似文献
9.
加速器质谱法测定深海锰结核样品中的^10Be 总被引：1，自引：0，他引：1
本文研究深海锰结核中＾１０Ｂｅ的加速器质谱法分析。提出了ＮａＯＨ和ＥＤＴＡ分离纯化－ＢｅＯ制样－加速器质谱法测量＾１０ＢｅＯ制样－加速器质谱法测量＾１０Ｂｅ的分析程序。研究结果表明,该法回收率较高,分离效果较好,按该法制备的ｅＯ靶能较好地满足加速器质谱法对测量＾１０Ｂｅ的要求。利用该法测得北太平洋两个锰结核的生长速率分别为２．７ｍｍ／Ｍａ和１．５ｍｍ／Ｍａ。这些结果与其他研究者所测数据相比,非常一 相似文献
10.