首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2篇
  免费   1篇
地质学   2篇
自然地理   1篇
  2007年   1篇
  2003年   2篇
排序方式: 共有3条查询结果,搜索用时 0 毫秒
1
1.
The isotopic composition of dissolved boron, in combination with the elemental concentrations of B, Cl and salinities in freshwater-seawater mixed samples taken from the estuary of the Changjiang River, the largest one in China, was investigated in detail in this study. Brackish water and seawater samples from the estuary of the Changjiang River were collected during low water season in November, 1998. Boron isotopic compositions were determined by the Cs2BO^+2-graphite technique with a analytical uncertainty of 0.2‰ for NIST SRM 951 and an average analytical uncertainty of 0.8‰ for the samples. The isotopic compositions of boron, expressed in δ^11B, and boron concentrations in the Changjiang River at Nanjing and seawater from the open marine East Sea, China, are characterized by δ^11B values of -5.4‰ and 40.0‰, as well as 0.0272 and 4.43 mg B/L, respectively. Well-defined correlations between δ^11B values, B concentrations and Cl concentrations are interpreted in terms of binary mixing between fiver input water and East Sea seawater by a process of straightforward dilution. The offsets of δ^11B values are not related to the contents of clastic sediment and to the addition of boron. These relationships favor a conservative behavior of boron at the estuarine of the Changjiang River.  相似文献   
2.
采用Cs2BO2^ -石墨技术对长江口咸淡水混合过程中溶解态的硼同位素组成进行了测定,得到混合水的δ^11B的变化范围是39.9‰~12.δ^11‰,硼浓度的变化范围是2.07~O.0429μg/mL。结果表明,混合水的硼浓度和δ^11B均随离长江口岸距离的增加而增加,但硼浓度与其它所有水化学成分一样,只呈线性关系而增加。而δ^11B值是呈对数关系而增加,即在混合的初期,混合水的δ^11B值随海水的掺入而急剧增加至海水的δ^11B值后趋于稳定。混合水δ^11B值的这种变化是长江淡水与海水简单混合的结果。  相似文献   
3.
以NBSSRM 95 1硼标准溶液为研究对象 ,测定了不同温度以及是否加入甘露醇的情况下浓缩硼酸溶液后硼的回收率和11B 10 B比值。通过分析硼回收率和11B 10 B比值随温度和甘露醇变化的趋势 ,初步得出了浓缩硼酸样品的较佳条件为 :在被浓缩样品中加入甘露醇并在 85℃左右的温度下进行浓缩。  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号