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681.
A 400-year record of black carbon flux in the Xisha archipelago, South China Sea and its implication 总被引:2,自引:0,他引:2
Liu X Xu L Sun L Liu F Wang Y Yan H Liu Y Luo Y Huang J 《Marine pollution bulletin》2011,62(10):2205-2212
We reconstructed the first long-term (∼400 years) records of black carbon (BC) deposition flux from three ornithogenic sediment profiles, which were collected from three remote, isolated islets of the Xisha archipelago, South China Sea. The significant correlations between black carbon, organic matter and excess 210Pb suggested that black carbon was mainly derived from atmospheric deposition, and further enriched by plant-derived organic matter in sediments. During the past 400 years, the BC flux remained relatively low before the onset of 20th century; it started to increase from approximately 1900 AD, and peaked around the 1970s. In the recent 30 years, the BC flux seemed to display decreasing trend, very likely due to the change of energy structure and development of pollution control techniques. In comparison with marginal sea regions that are greatly impacted by anthropogenic activities, these pristine Xisha islands were not significantly influenced by black carbon of anthropogenic origin. 相似文献
682.
Two-month continuous waveforms of 108 broadband seismic stations in Fujian Province and its adjacent areas are used to compute noise cross-correlation function (NCF). The signal quality of NCF is improved via the application of time-frequency phase weighted stacking. The Rayleigh and Love waves group velocities between 1s-20s are measured on the symmetrical component of the NCF with the multiple filter method. More than 5,000 Rayleigh wave dispersion curves and about 4,000 Love wave dispersion curves are obtained and used to invert for group velocity maps. This data set provides about 50km resolution that is demonstrated with checkerboard tests. Considering the off great circle effect in inhomogeneous medium, the ray path is traced based on the travel time field computed with a finite difference method. The inverted group velocity maps show good correlation with the geological features in the upper and middle crust. The Fuzhou basin and Zhangzhou basin showed low velocity on the short period group velocity maps. On the long period group velocity maps, the low velocity anomaly in the high heat flow region near Zhangzhou and clear velocity contrast across the Zhenghe-Dapu faults, which suggests that the Zhenghe-Dapu fault might be a deep fault. 相似文献
683.
To study the dynamic response of vertical and batter pile groups in saturated sand, dynamic tests of these pile groups in saturated sand were carried out using the ZJU400 geotechnical centrifuge at Zhejiang University. The following results were obtained.(1) As the motion intensity increased, the peak acceleration in soil layers at different depths significantly decreased, indicating that the soil stiffness was significantly reduced.(2) During the motion process, the instantaneous bending moment... 相似文献
684.
WANG Feifei LIU Chiyang NIU Haiqing ZHOU Ningchao LI Xiuhu LUO Wei ZHANG Dongdong ZHAO Yan 《《地质学报》英文版》2018,92(1):406-407
正Objective The Ordos Basin located in the western part of the North China Craton bears various energy resources such as oil,gas,coal and uranium.It is one of the richest uranium-bearing basins in China.Since the discovery of the large-scale Dongsheng,Hangjinqi and Daying uranium deposits in the north of the Ordos Basin,a new 相似文献
685.
Actual granitoid analytical data of 767 composited samples are presented here.The data source is 6080 samples collected mainly from 750 large- to middle-sized granitoid bodies across China. Data from the composited samples,which includes that of 70 elements,is analyzed according to geological age—Archeozoic(Ar),Proterozoic(Pt),Eopaleozoic(Pz_1),Neopaleozoic(Pz_2),Mesozoic(Mz), and Cenozoic(Cz)—and three major compositional varieties,e.g.alkali-feldspar granite,syenogranite and adamellite.Petrochemical pa... 相似文献
686.
CHENG Yan REN Jingling LI Dandan LIU Sumei ZHANG Jing 《中国海洋大学学报(英文版)》2006,5(3):243-250
Water samples were collected in the coastal area of the Changjiang Estuary on four cruises from August 2002 to May 2003. The seasonal variations of dissolved inorganic arsenic (DIAs) distributions were analyzed. The results showed that the distributions of DIAs were mainly influenced by Water (KSSW). The concentration of the total dissolved the terrestrial input and the intrusion of the Kuroshio Subsurface inorganic arsenic (TDIAs) decreased consecutively from winter to summer, while it increased in autumn. The distributions of TDIAs showed some relationships with salinity and suspended particulate matter (SPM). The relationships between DIAs speciation (including arsenite [ As( Ⅲ ) ] and arsenate [ As( Ⅴ ) ]), biological activity and the availabilities of the phosphate were investigated in the study area for the cruise August 2002. The ratio of As (Ⅲ)/TDIAs increased with the decrease of phosphate concentrations. In the bottom water, the As( Ⅲ )/TDIAs ratio decreased with the increasing of N/P. The concentration of TDIAs decreased 28.7% approximately after the occurrence of harmful algal blooms (HAB) because of the uptake of arsenate by algae. Further study is needed about the arsenic source/sink relationships in their vertical or horizontal profiles and the uptake mechanism during the occurrence of harmful algal blooms. 相似文献
687.
After many years' endeavor of research and application practice, the ocean color remote sensing in China has been growing into a new technique with valuable practicality from its initiate stage of trial research. With the aim of operational service, several kinds of ocean color remote sensing application systems have been developed and realized the long-term marine environmental monitoring utilizing the real-time or near real-time satellite and airborne remote sensing data. New progresses in the technology and application of ocean color remote sensing in China are described, including the research of key techniques and the development of various application systems. Meanwhile, according to the application status and demand, the prospective development of Chinese ocean color remote sensing is brought forward. With Chinese second ocean color satellite ( HY-1 B) orbiting on 11 April 2007 and the development of airborne ocean color remote sensing system for Chinese surveillance planes, great strides will take place in Chinese ocean color remote sensing application with the unique function in marine monitoring, resources management and national security, etc. 相似文献
688.
Xiaohe Lai Chuqing Zeng Yan Su Shaoxiang Huang Jianping Jia Cheng Chen Jun Jiang 《海洋学报(英文版)》2023,(7):160-174
The change of coastal wetland vulnerability affects the ecological environment and the economic development of the estuary area. In the past, most of the assessment studies on the vulnerability of coastal ecosystems stayed in static qualitative research, lacking predictability, and the qualitative and quantitative relationship was not objective enough. In this study, the “Source-Pathway-Receptor-Consequence” model and the Intergovernmental Panel on Climate Change vulnerability definition were us... 相似文献
689.
Wanlin Zhai Jianhua Zhu Chuntao Chen Wu Zhou Longhao Yan Yufei Zhang Xiaoqi Huang Kai Guo 《海洋学报(英文版)》2023,(6):78-88
A dedicated GPS buoy is designed for calibration and validation(Cal/Val) of satellite altimeters since 2014. In order to evaluate the accuracy of the sea surface height(SSH) measured by the GPS buoy, twelve campaigns have been done within China sea area between 2014 and 2021. In six of these campaigns, two static Global Navigation Satellite System stations were installed at distances of <1 km and 19 km from the buoy to assess how the baseline length influenced the derived SSH from the buoy so... 相似文献
690.
Regional and persistent PM2.5 pollution seriously undermines the development of urban ecological civilizations and the advancement of high-quality economies. The producer service sector, an example of a typical knowledge-intensive service industry, plays an important role in advancing the manufacturing industry and fostering economic growth while concurrently improving urban environmental conditions. Based on panel data of prefecture-level cities in the Yellow River Basin from 2006 to... 相似文献