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柴达木盆地察尔汗古湖贝壳堤剖面碳酸盐和瓣鳃化石碳氧稳定同位素 被引量:21
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作者 常凤琴 张虎才 +5 位作者 陈玥 牛洁 杨明生 张文翔 雷国良 樊红芳 《第四纪研究》 CAS CSCD 北大核心 2007年第3期427-436,共10页
通过对柴达木盆地察尔汗古湖贝壳堤剖面沉积物、生物壳体碳酸盐同位素及沉积物碳酸盐含量等多项指标的分析,探讨了贝壳堤剖面记录39.6~17.1kaB.P.(未校正14C测年,下同)期间碳酸盐和贝壳化石碳氧稳定同位素的特征和相关关系,指出壳体化... 通过对柴达木盆地察尔汗古湖贝壳堤剖面沉积物、生物壳体碳酸盐同位素及沉积物碳酸盐含量等多项指标的分析,探讨了贝壳堤剖面记录39.6~17.1kaB.P.(未校正14C测年,下同)期间碳酸盐和贝壳化石碳氧稳定同位素的特征和相关关系,指出壳体化石及沉积物碳酸盐的碳氧同位素是湖泊水体温度和盐度的反映,其中δ18O对温度的指示意义更敏感,是湖泊和古气候演化很好的代用指标。根据这些指标重建的古气候与环境变化显示,在39.6~35.5kaB.P.期间,柴达木盆地处于温暖湿润期,周围山地降水增加,盆地内湖泊发育;自35.5kaB.P.开始,气候较前期更加湿润,是湖泊发育的最佳期;22.1kaB.P.以后,气候逐步转入较温暖的干燥期,湖泊开始萎缩、退化;末期17.1kaB.P.气候环境急剧恶化,形成石盐结晶,湖泊高湖面演化史结束。 展开更多
关键词 柴达木盆地 贝壳化石 碳酸盐稳定同位素 古气候
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Evaluation of nitrate source in groundwater of southern part of North China Plain based on multi-isotope 被引量:1
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作者 方晶晶 周爱国 +4 位作者 马传明 刘存富 蔡鹤生 甘义群 刘运德 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期610-618,共9页
Nitrate pollution in groundwater is a serious water quality problem that increases the risk of developing various cancers.Groundwater is the most important water resource and supports a population of 5 million in Anya... Nitrate pollution in groundwater is a serious water quality problem that increases the risk of developing various cancers.Groundwater is the most important water resource and supports a population of 5 million in Anyang area of the southern part of the North China Plain. Determining the source of nitrate pollution is the challenge in hydrology area due to the complex processes of migration and transformation. A new method is presented to determine the source of nitrogen pollution by combining the composition characteristics of stable carbon isotope in dissolved organic carbon in groundwater. The source of groundwater nitrate is dominated by agricultural fertilizers, as well as manure and wastewater. Mineralization, nitrification and mixing processes occur in the groundwater recharge area, whereas the confined groundwater area is dominated by denitrification processes. 展开更多
关键词 δ^12NNO3 δ^18ONO3 δ^13CDOC esophageal cancer GROUNDWATER
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