Relationships between persistent organic pollutants and carbonaceous materials in aquatic sediments of Taiwan   总被引：4，自引：0，他引：4  

Chin-Chang Hung  Gwo-Ching Gong  Hung-Yu Chen  Jian-Ming Wu  Fan-Hua Nan  Peter H. Santschi 《Marine pollution bulletin》2010,60(7):1010-1017

Recent studies have shown that many persistent organic pollutants (POPs, e.g., polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and various pesticides), are strongly associated with carbonaceous materials (including organic carbon (OC) and black carbon (BC)). We hypothesize that carbonaceous materials can be used as a first-order pollution index, to indicate areas where POP pollution may require further investigation. We tested our hypothesis and found that strong, positive correlations between BC and OC contents versus the concentrations of PCBs (and PAHs) existed in estuarine sediments of the Danshui River in 2005 and 2008. Thus, our preliminary results demonstrate that POC and BC are potential indicators of the POP pollution potential in fluvial sediments of the Danshui River in Taiwan. This innovative approach can provide a simple, relatively inexpensive and expedient means to monitor concentrations of POPs in polluted aquatic sediments of Taiwan, and/or those having a legacy of POP inputs.  相似文献   

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巩岩  党亚民 《大地测量与地球动力学》2010,30(5):86-89

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许双安  姚宜斌  孔建  龚佩佩 《大地测量与地球动力学》2010,30(4):117-121

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Molecular phylogeny and species separation of five morphologically similar Holosticha-complex ciliates (Protozoa, Ciliophora) using ARDRA riboprinting and multigene sequence data     

高凤  伊珍珍  龚骏  宋微波 《中国海洋湖沼学报》2010,28(3):542-548

  相似文献   

联合速度建模及其在反射波法隧道超前预报中的应用     

巩向博  韩立国  牛建军  张晓培  王德利  杜立志 《应用地球物理》2010,7(3):265-271

We propose a combined migration velocity analysis and imaging method based on Kirchhoff integral migration and reverse time migration, using the residual curvature analysis and layer stripping strategy to build the velocity model. This method improves the image resolution of Kirchhoff integral migration and reduces the computations of the reverse time migration. It combines the advantages of efficiency and accuracy of the two migration methods. Its application in tunnel seismic prediction shows good results. Numerical experiments show that the imaging results of reverse time migration are better than the imaging results of Kirchhoff integral migration in many aspects of tunnel prediction. Field data show that this method has efficient computations and can establish a reasonable velocity model and a high quality imaging section. Combination with geological information can make an accurate prediction of the front of the tunnel geological structure.  相似文献   

Late Cretaceous-Cenozoic exhumation of the Yanji area, northeast China: Constraints from fission-track thermochronology     

Xiaoming  Li  Guilun  Gong  Xiaoyong  Yang  Qiaosong  Zeng 《Island Arc》2010,19(1):120-133

The Yanji area, located at the border of China, Russia, and Korea, where the Phanerozoic granitoids have been widely exposed, was considered part of the orogenic collage between the North China Block in the south and the Jiamusi–Khanka Massifs in the northeast. In this study, the cooling and inferred uplift and denudation history since the late Mesozoic are intensively studied by carrying out apatite and zircon fission-track analyses, together with electron microprobe analyses (EMPA) of chemical compositions of apatite from the granitoid samples in the Yanji area. The results show that: (i) zircon and apatite fission-track ages range 91.7–99.6 Ma and 76.5–85.4 Ma, respectively; (ii) all apatite fission-track length distributions are unimodal and yield mean lengths of 12–13.2 µm, and the apatites are attributed to chlorine-bearing fluorapatite as revealed by EMPA results; and (iii) the thermal history modeling results based on apatite fission-track grain ages and length distributions indicate that the time–temperature paths display similar patterns and the cooling has been accelerated for each sample since ca 15 Ma. Thus, we conclude that sequential cooling, involving two rapid (95–80 Ma and ca 15–0 Ma) and one slow (80–15 Ma) cooling, has taken place through the exhumation of the Yanji area since the late Cretaceous. The maximum exhumation is more than 5 km under a steady-state geothermal gradient of 35°C/km. Combined with the tectonic setting, this exhumation is possibly related to the subduction of the Pacific Plate beneath the Eurasian Plate since the late Cretaceous.  相似文献   

赣南葛廷坑钼矿辉钼矿Re-Os年龄及其地质意义   总被引：1，自引：0，他引：1       下载免费PDF全文

吴俊华  赵赣  屈文俊  袁承先  龚敏  刘爽  李牟  周雪桂  廖明和  魏俊浩  马振东 《地学前缘》2011,18(3):261-267

赣南葛廷坑钼矿为产在花岗斑岩与围岩内外接触带的中型斑岩型钼矿床。通过对矿区含矿石英脉中7个辉钼矿样品进行Re Os同位素测定,获得等时线年龄及模式年龄的加权平均值分别为(1594±16)和(1588±13) Ma。等时线初始187Os为(0001±0055)ng/g,MSWD=17。葛廷坑钼矿形成于中侏罗世中晚期,其成矿年龄对应于华南中晚侏罗世第二成矿阶段(170～150 Ma),与区域内160 Ma左右的钨锡矿成矿作用基本一致。区域上华南钼的成矿时间具有连续性,在165～90 Ma均有发生。  相似文献   

使用气象目标物验证珠海〖CDF*2〗澳门双偏振雷达的差分反射率标定     

詹棠  龚志鹏  郑浩阳  夏冬  滕超  邱国强 《气象科技》2019,47(1):10-18

为了寻求适合珠海-澳门双偏振雷达的差分反射率标定方法,提升其探测的准确性和稳定性,对珠澳雷达的太阳法和垂直指向法的标定结果进行了分析对比。对比表明两个标定方法确定的系统偏差之间存在较大的差异。为了确定真实的系统偏差,基于业务运行的体积扫描数据,在初始差分相移订正的基础上,用差分相移、反射率、信噪比和相关系数作为筛选条件,筛选了适合作为标定参照物的小雨和干雪,对珠澳雷达的标定结果进行了验证并分析了标定误差的成因。结果表明以小雨和干雪作为目标物得到的差分反射率系统偏差和太阳扫描法得到的结果非常一致,且在超过两个月时间内表现较为稳定,可以用于对雷达系统的差分反射率偏差进行长期的在线监控。垂直指向法标定的结果存在明显偏差。与英国Thurnham C波段雷达以及南京大学C波段雷达的垂直入射标定数据的横向对比和分析表明,珠澳雷达的垂直指向法标定受到位于天线罩顶部的航空障碍灯和维护窗的影响,使得标定结果出现偏差。  相似文献   

海河流域水汽输送及其变化特征分析          下载免费PDF全文

朱玲  柳艳香  左洪超  向卫国  龚强  于华深  蔺娜  晁华  顾正强 《气候变化研究进展》2011,7(3):184-188

根据海河流域测站降水资料、NCEP/NCAR再分析资料和日本气象厅JRA-25资料,分析了1951—2008年夏季海河流域大气水汽含量的变化以及不同环流形势下的水汽输送特征,结果表明：海河流域大气水汽含量存在显著的年代际变化特征,与降水量存在显著统计相关;海河流域上空纬向水汽输送主要发生在850~700 hPa之间,经向水汽输送在850 hPa以下存在强的水汽输送带,它是海河流域水汽的主要贡献者,也是影响海河流域降水的最主要因素之一。气旋型环流和南风型环流对海河流域水汽输送有较大影响。  相似文献   

The water content and hydrogen isotope composition of continental lithospheric mantle and mantle-derived mafic igneous rocks in eastern China     

Zheng Xu  Bin Gong  Zifu Zhao 《中国科学:地球科学(英文版)》2016,59(5):910-926

The water contents of minerals and whole-rock in mantle-derived xenoliths from eastern China exhibit large variations and are generally lower than those from other on- and off-craton lithotectonic units. Nevertheless, the water contents of mineral and whole-rock in Junan peridotite xenoliths, which sourced from the juvenile lithospheric mantle, are generally higher than those elsewhere in eastern China. This suggests that the initial water content of juvenile lithospheric mantle is not low. There is no obvious correlation between the water contents and Mg^# values of minerals in the mantle xenoliths and no occurrence of diffusion profile in pyroxene, suggesting no relationship between the low water content of mantle xenolith and the diffusion loss of water during xenolith ascent with host basaltic magmas. If the subcontinental lithospheric mantle (SCLM) base is heated by the asthenospheric mantle, the diffusion loss of water is expected to occur. On the other hand, extraction of basaltic melts from the SCLM is a more efficient mechanism to reduce the water content of xenoliths. The primary melts of Mesozoic and Cenozoic basalts in eastern China have water contents, as calculated from the water contents of phenocrysts, higher than those of normal mid-ocean ridge basalts (MORB). The Mesozoic basalts exhibit similar water contents to those of island arc basalts, whereas the Cenozoic basalts exhibit comparable water contents to oceanic island basalts and backarc basin basalts with some of them resembling island arc basalts. These observations suggest the water enrichment in the mantle source of continental basalts due to metasomatism by aqueous fluids and hydrous melts derived from dehydration and melting of deeply subducted crust. Mantle-derived megacrysts, minerals in xenoliths and phenocrysts in basalts from eastern China also exhibit largely variable hydrogen isotope compositions, indicating a large isotopic heterogeneity for the Cenozoic SCLM in eastern China. The water content that is higher than that of depleted MORB mantle and the hydrogen isotope composition that is deviated from that of depleted MORB mantle suggest that the Cenozoic continental lithospheric mantle suffered the metasomatism by hydrous melts derived from partial melting of the subducted Pacific slab below eastern China continent. The metasomatism would lead to the increase of water content in the SCLM base and then to the decrease of its viscosity. As a consequence, the SCLM base would be weakened and thus susceptible to tectonic erosion and delamination. As such, the crust-mantle interaction in oceanic subduction channel is the major cause for thinning of the craton lithosphere in North China.  相似文献