Biomarker evidence for paleoenvironmental changes in the southern Yellow Sea over the last 8200 years   总被引：2，自引：0，他引：2  

邢磊  赵美训  张海龙  赵晓晨  赵晓辉  杨作升  刘传联 《中国海洋湖沼学报》2012,30(1):1-11

Previous studies have indicated that the Yellow Sea underwent significant environmental changes during the Holocene, but many questions remain concerning the timing of the establishment of the modern circulation system, which would have major implications for the Yellow Sea ecosystem and carbon cycle. In this study, marine and terrestrial biomarkers were analyzed in Core YE-2 from a muddy area in the southern Yellow Sea to reconstruct Holocene environmental and phytoplankton community change. The content of three individual marine phytoplankton biomarkers (alkenones, brassicasterol and dinosterol) all display a similar trend, and their total contents during the early Holocene (362 ng/g) were lower than those during the mid-late Holocene (991 ng/g). On the other hand, the contents of terrestrial biomarkers (C27+C29+C31n-alkanes) during the early Holocene (1 661 ng/g) were about three times higher than those during the mid-late Holocene (499 ng/g). Our biomarker results suggest that the modern circulation system of the Yellow Sea was established by 5-6 ka, and resulted in higher marine productivity and lower terrestrial organic matter inputs. Biomarker ratios were used to estimate shifts in phytoplankton community structure in response to mid-Holocene (5-6 ka) environmental changes in the Yellow Sea, revealing a transition from a dinoflagellate-diatom dominant community structure during the early Holocene to a coccolithophore-dominant community structure during the mid-late Holocene.  相似文献   

REE geochemistry of surface sediments in the Chukchi Sea   总被引：4，自引：0，他引：4  

陈志华  高爱国  刘焱光  孙海清  石学法  杨作升 《中国科学D辑(英文版)》2003,46(6):603-611

Rare earth elements (including the lanthanides and Y) have analogical chemical properties and low solubility, and they are not easy to transfer and take inter-element fractionation during geological processes such as weathering, disintegration, transporta…  相似文献   

大洋钻探25年（一）     

杨作升  郭玉贵 《海洋地质与第四纪地质》1995,15(1):143-151

大洋钻探２５年（一）杨作升，郭志刚，郭玉贵，崔青编译（青岛海洋大学河口海岸带研究所，青岛，２６６００３）（地矿部海洋地质研究所，青岛，２６６０７１）译者注：为纪念大洋钻探（ＯｃｅａｎＤｒｉｌｌｉｎｇ）２５周年（１９６８－１９９３），美国《Ｏ－ｃｅａｎ...  相似文献   

现行黄河口海域泥沙冲淤的定量计算及其规律探讨     

孙效功  杨作升  陈彰榕 《海洋学报》1993,15(1):129-136

本文利用现行黄河口海域多年的水深测量资料,用计算机绘制了黄河口冲淤等值线图和冲淤立体图.在此基础上,详细地分析研究了黄河口海域泥沙冲淤变化的规律和特点.从定量的角度,为河口治理及各种海洋工程建设提供了科学依据.  相似文献   

MapInfo在黄河口拦门沙研究中的应用     

张彩云  杨作升  张勇  黄海挺 《海岸工程》2002,21(1):1-5

根据MapInfo所具有的功能特点,讨论了MapInfo在黄河口拦门沙中的应用.在黄河口拦门沙的研究中,通过使用MapInfo软件,使我们对拦门沙的研究从定性走向定量,从简单的文字描述达到直观的地图展示,为拦门沙的研究提供了一种新的手段.  相似文献