Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in ...Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in the sea area,with surface salinity>30,(NO_3)^-concentration has shown an obvious increase,(PO_4)^(3-) has not changed greatly and dissolved reactive silica((SiO_3)^(2-)) has deceased dramatically.An examination of the elemental ratio of(NO_3)^-to(PO_4)^(3-) at the mouth of the Changjiang River did not show a systematic trend from the 1960s to 2000s largely because both nutrients increased simultaneously.In comparison,the elemental ratio of dissolved inorganic nitrogen(DIN) to(PO_4)^(3-) in surface seawater,with salinity>22,has shown a clearly increasing trend.Furthermore,an overall historical change of the(SiO_3)^(2-):(PO_4)^(3-) ratio has undergone a reverse trend in this area.Based on the changes of(SiO_3)^(2-):(PO_4)^(3-) and DIN:(PO_4)^(3-) ratios,we can conclude that an overall historical change of(SiO_3)^(2-):DIN ratio has decreased in this area from the 1950-1960s to 2000s.The argument that phytoplankton productivity in the Changjiang estuary has been enhanced by increasing nutrient input from the riverine transport was supported by these results.A comparative study analyzing the shift of phytoplankton composition from the mid-1980s to 2000s was also made.The results indicated that the average yearly percentage of diatom species in the Changjiang estuary has decreased from 84.6% during 1985-1986 to 69.8% during 2004-2005.Furthermore,the average yearly percentage of diatom abundance in the Changjiang estuary decreased from 99.5% during to 75.5% over the same time period,while the abundance of dinoflagellates has increased dramatically,from 0.7% to 25.4%.展开更多
Based on the custom of stone bridge and village, by categorizing and interpreting the relationship between Lufeng Bridge （鲁封桥） and Luqiao Village （鲁桥村） in Southern Shandong Province, China, this paper focuse...Based on the custom of stone bridge and village, by categorizing and interpreting the relationship between Lufeng Bridge （鲁封桥） and Luqiao Village （鲁桥村） in Southern Shandong Province, China, this paper focuses on discussing the dynamic of rural society change in China and the practice of village life world. It provides detailed materials of field research about folk life of stone bridge and village in North China. Here village life world not only includes the folk integration of their everyday life, but also covers local villagers cognitive attitude towards village, such as village history, legend, belief, ritual, clan and other everyday life styles. Expounding and reconstructing of village life world, shows the essential meanings and categories of bridge folklore, it also demonstrates the consequence of shifting connection between stone bridge and village life. Firstly, the crucial context of understanding village life world is still promising. Secondly, folklore fieldwork is an significant part to comprehend the connotation of village life world.展开更多
基金Supported by the National Natural Science Foundation of China for Creative Research Groups(No.40821004)the High Technology Research and Development Program of China(863 Program)(No.2008AA09Z107)the National Basic Research Program of China(973 Program)(No.2010CB428706)
文摘Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in the sea area,with surface salinity>30,(NO_3)^-concentration has shown an obvious increase,(PO_4)^(3-) has not changed greatly and dissolved reactive silica((SiO_3)^(2-)) has deceased dramatically.An examination of the elemental ratio of(NO_3)^-to(PO_4)^(3-) at the mouth of the Changjiang River did not show a systematic trend from the 1960s to 2000s largely because both nutrients increased simultaneously.In comparison,the elemental ratio of dissolved inorganic nitrogen(DIN) to(PO_4)^(3-) in surface seawater,with salinity>22,has shown a clearly increasing trend.Furthermore,an overall historical change of the(SiO_3)^(2-):(PO_4)^(3-) ratio has undergone a reverse trend in this area.Based on the changes of(SiO_3)^(2-):(PO_4)^(3-) and DIN:(PO_4)^(3-) ratios,we can conclude that an overall historical change of(SiO_3)^(2-):DIN ratio has decreased in this area from the 1950-1960s to 2000s.The argument that phytoplankton productivity in the Changjiang estuary has been enhanced by increasing nutrient input from the riverine transport was supported by these results.A comparative study analyzing the shift of phytoplankton composition from the mid-1980s to 2000s was also made.The results indicated that the average yearly percentage of diatom species in the Changjiang estuary has decreased from 84.6% during 1985-1986 to 69.8% during 2004-2005.Furthermore,the average yearly percentage of diatom abundance in the Changjiang estuary decreased from 99.5% during to 75.5% over the same time period,while the abundance of dinoflagellates has increased dramatically,from 0.7% to 25.4%.
文摘Based on the custom of stone bridge and village, by categorizing and interpreting the relationship between Lufeng Bridge （鲁封桥） and Luqiao Village （鲁桥村） in Southern Shandong Province, China, this paper focuses on discussing the dynamic of rural society change in China and the practice of village life world. It provides detailed materials of field research about folk life of stone bridge and village in North China. Here village life world not only includes the folk integration of their everyday life, but also covers local villagers cognitive attitude towards village, such as village history, legend, belief, ritual, clan and other everyday life styles. Expounding and reconstructing of village life world, shows the essential meanings and categories of bridge folklore, it also demonstrates the consequence of shifting connection between stone bridge and village life. Firstly, the crucial context of understanding village life world is still promising. Secondly, folklore fieldwork is an significant part to comprehend the connotation of village life world.
