Four seasonal field investigations have been conducted in the Seven Stars Lake in Zhaoqing between Apr.1996 and Jan.1997. The water of the lake was sampled once for each season. Three major eutrophication elements, ph...Four seasonal field investigations have been conducted in the Seven Stars Lake in Zhaoqing between Apr.1996 and Jan.1997. The water of the lake was sampled once for each season. Three major eutrophication elements, phytoplankton,nitrate and phosphate were analyzed quantitatively. According to the monitoring data,the concectration levels of the elements and their distributions,relationships among the elements were analyzed. The results are important for predicting eutrophication of the water and studying the mechanisms of the eutrophication in the Seven Sear Lake.展开更多
本文研究了五个土壤剖面(10个土壤层次)硒的含量范围及其分布特征。对于土壤含硒量的 DAN 荧光分光光度法的测定作了较为详尽的介绍。对土壤样品的消解处理作了较深入的研究。并对分析结果进行了论证。该方法相对标准偏差为3.3%,加标回...本文研究了五个土壤剖面(10个土壤层次)硒的含量范围及其分布特征。对于土壤含硒量的 DAN 荧光分光光度法的测定作了较为详尽的介绍。对土壤样品的消解处理作了较深入的研究。并对分析结果进行了论证。该方法相对标准偏差为3.3%,加标回收率在89.7%~93.5%之间。结果是满意的。该调查区内土壤中硒有如下分布特征:表层含量高于底层,由上而下呈递降趋势。且不同土质硒的含量分布有差异,一般粘土壤中硒的含量大于砂壤土。展开更多
文摘Four seasonal field investigations have been conducted in the Seven Stars Lake in Zhaoqing between Apr.1996 and Jan.1997. The water of the lake was sampled once for each season. Three major eutrophication elements, phytoplankton,nitrate and phosphate were analyzed quantitatively. According to the monitoring data,the concectration levels of the elements and their distributions,relationships among the elements were analyzed. The results are important for predicting eutrophication of the water and studying the mechanisms of the eutrophication in the Seven Sear Lake.
文摘本文研究了五个土壤剖面(10个土壤层次)硒的含量范围及其分布特征。对于土壤含硒量的 DAN 荧光分光光度法的测定作了较为详尽的介绍。对土壤样品的消解处理作了较深入的研究。并对分析结果进行了论证。该方法相对标准偏差为3.3%,加标回收率在89.7%~93.5%之间。结果是满意的。该调查区内土壤中硒有如下分布特征:表层含量高于底层,由上而下呈递降趋势。且不同土质硒的含量分布有差异,一般粘土壤中硒的含量大于砂壤土。