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891.
以褐菖鲉(Sebastiscus marmoratus)细胞色素P4501A四种生物标志物,即鳃丝EROD活性、肝EROD活性、肝CYP1A mRNA和肝CYP1A蛋白为指标,在泉州湾海域选择6个站位(包括1个对照站位),开展了为期两周的野外监测实验,研究了上述生物标志物的变化特征以及它们同表层海水中石油类含量和沉积物物中16种优先监控的PAHs含量之间的相关性,并利用新一代综合生物标志物响应指数法(IBRv2)对监测站位石油类和PAHs污染效应进行了评价.结果显示,不同站位的上述四种生物标志物变化趋势基本一致;生物标志物的变化与相应站位表层水中石油类含量及沉积物中PAHs总含量相吻合;IBRv2分析结果表明,各监测站位IBRv2指数介于1.5~4.2之间,其中2号站环境污染压力最大,4号站最小.在复杂的海洋污染条件下,采用CYP1A多种生物标志物监测技术能够更加全面反映石油类等污染及其生物效应状况. 相似文献
892.
We studied high-grade metamorphic rocks of the El Cristo hill area of the Tandilia belt. Mineral analyses and thermodynamic calculations were carried out for two adjacent rock samples: an amphibole–biotite gneiss and a garnet–biotite-bearing migmatite. Peritectic garnets in the migmatite show core compositions of pyr4.5(gro + andr)10spes6alm79.5 changing to pyr3.5(gro + andr)17spes6alm73.5 at their thin rims. Garnet compositions in the gneiss are pyr6.5(gro + andr)26spes12alm55.5 and pyr4.5(gro + andr)34spes12alm49.5 for core and rim, respectively. A P–T path was constructed by calculating pseudosections in the 11-component system Si–Ti–Al–Fe–Mn–Mg–Ca–Na–K–O–H and contouring them by isopleths for garnet components using the PERPLE_X software package. Supra-solidus crystallization of garnet cores in the migmatite began at 5.8 kbar and 660 °C. Garnet rims equilibrated at 7.0 kbar and 640 °C compatible with garnet cores in the amphibole–biotite gneiss (7.6 kbar and 660 °C). The further chemical development of garnet in this rock points to P–T conditions of 11.6 kbar and 620 °C and 12.2 kbar and 595 °C (outermost garnet rim). At this high-pressure stage Ca-amphibole was not stable. Most biotite formed during exhumation whereas the high-pressure accessory minerals, titanite and epidote, persisted. According to the obtained anti-clockwise P–T path the originally partly melted material was tectonically transported from ∼22 km (middle crust) to ∼40 km (lower crust) depths reaching a geothermal gradient as low as 15 °C km−1. This transport probably occurred along a major suture zone, which was active during the Paleoproterozoic (2.25–2.10 Ga), before a terminating collision of terranes near the SW boundary of the Rio de la Plata craton. 相似文献
893.
主要研究视频图像监控系统中的云台控制器,以CAN总线为数据传输核心,采用P89C51单片机芯片作为下位机的微处理器。PC机通过并口与CAN总线控制器SJA1000进行通信,整个控制器系统中采用Ph ilips公司的SJA1000、82C250芯片和高速光电耦合器6N137。SJA1000是独立的CAN通信控制器,82C250为高性能CAN总线收发器。微处理器负责SJA1000的初始化,设定所要控制的云台转动和镜头变焦转换等相关数据,通过控制SJA1000来实现数据的接收和发送等通信任务。 相似文献
894.
Qing LIN Xinying ZHANG Guijin LU 《中国地球化学学报》2006,25(B08):215-216
Lead is one of the major heavy-metal contaminants in water environments. It can exert a stress on the growth of submersed plants through changing the activities of carbon-fixation enzymes in their photosynthesis. In this work, a worldwide distributed species of submersed plants- Potamogeton pectinatus, which can survive in different water environments such as in Dianchi Lake, a severe eutrophic lake, was cultivated in improved Hoagland's solution and treated with different concentrations of lead. In order to realize the effect of lead on the photosynthesis of this plant, the chlorophyll contents were determined and the activities of carbon-fixation enzymes including ribulose bisphosphate carboxylase (RuBPc), phosphoenolpyruvate carboxylase (PEPc) and carbonic anhydrase (CA) were analyzed. 相似文献
895.
PP/PS Wavefield separation by independent component analysis 总被引:1,自引:0,他引:1
Mirko van der Baan 《Geophysical Journal International》2006,166(1):339-348
896.
897.
陈培善 《地震学报(英文版)》2007,20(4):477-478
Illustration All the data in this catalog are chosen from the ″Preliminary Seismological Report of Chinese Seismic Stations″ (Its abbreviation is ″Monthly Report″). The catalog includes the events of M≥4.7 in and near China and M≥6 all over the world. The ″Monthly Report″ is monthly compiled by the Ninth Section of Institute of Geophysics, China Earthquake Administration. 相似文献
898.
HUANG XianYu JIAO Dan LU LiQiang XIE ShuCheng HUANG JunHua WANG YongBiao YIN HongFu WANG HongMei ZHANG KeXin & LAI XuLong Key Laboratory of Biogeology Environmental Geology Ministry of Education and the State Key Laboratory of GPMR China University of Geosciences Wuhan China Faculty of Material Science Chemical Engineering China University of Geosciences Wuhan China School of Environmental Studies China University of Geosciences Wuhan China 《中国科学D辑(英文版)》2007,50(7):1052-1059
The environmental conditions and the biotic crisis during the Permo-Triassic (Tr/P) transition received increasing attention in the past decades. Presented herein are the molecular fossil records of cyano-bacteria and green sulfur bacteria,the base of the marine ecosystem,to highlight the episodic nature of both the environment and the biotic crisis during this critical period. At least two episodes of cyano-bacterial expansion are documented by 2-methylhopanes ranging from C28 to C32 in carbon number,indicative of the instable marine ecosystem and the fluctuant aquatic nutrients. Meanwhile,the index of 2-alkyl-1,3,4-trimethylbenzenes (biomarkers of green sulfur bacteria) and the ratio of pristane to phy-tane (Pr/Ph) witness the fluctuation of sedimentary environmental redox conditions. The above mo-lecular evidence suggests the occurrence of highly fluctuating environmental conditions during the Tr/P transition,which is consistent with,and probably the cause of,the multi-phased biotic crisis and the prolonged faunal recovery. 相似文献
899.
基于中国新疆及中亚地区大量天然地震和地下爆炸,检验了较大震级情况下得到的区域P/S震相幅值比识别判据对低震级地震事件的适用性. 分析结果表明,对较大震级地震事件具有较好识别效果的P/S震相幅值比判据对低震级事件同样适用,而且对低震级事件也具有与较大震级事件大致相当的识别效果. 据WMQ、BLK、MUL和MAK台的25个识别效果较好的P/S震相幅值比判据统计, 大于ML3.5和ML3.5以下地震事件的误识率之差约为2个百分点. 相似文献
900.
陈培善 《地震学报(英文版)》2006,19(4):483-484
All the data in this catalog are chosen from the "Preliminary Seismological Report of Chinese Seismic Stations" (Its abbreviation is "Monthly Report"). The catalog includes the events of M≥4.7 in and near China and M≥6 all over the world. The "Monthly Report" is monthly compiled by the Ninth Section of Institute of Geoohysics, China Earthquake Administration. 相似文献