Comparative petroleum hydrocarbons levels and biochemical responses in mussels from hydrothermal vents (Bathymodiolus azoricus) and coastal environments (Mytilus galloprovincialis)

Aliphatic hydrocarbons and PAHs in the whole soft tissues of Bathymodiolus azoricus from three Mid-Atlantic Ridge hydrothermal vents (Menez-Gwen, Lucky Strike and Rainbow), and Mytilus galloprovincialis from three contaminated coastal sites in South Portugal were analysed, and its effects on the digestive gland microsomes mixed-function oxygenase system (MFO) were assessed. Aliphatic hydrocarbons levels were present in the same magnitude in both coastal and hydrothermal environments, while the UCM (unresolved complex mixture) for coastal mussels were higher than in vent mussels. In general, significantly higher PAHs concentrations were found in coastal mussels, compared to B. azoricus where low molecular weight PAHs (2-3 rings) represented the majority of PAHs contrarily to what was observed in M. galloprovincialis. The MFO components were present in both mussel species, and were detected in vent mussels for the first time. However this system seems to have different roles in species from these contrasting environments. In coastal mussels MFO responded to hydrocarbon contamination while response in hydrothermal organisms appeared to be related mainly to endogenous factors.     

Lung function in subjects exposed to crude oil spill into sea water

A Greek oil-tanker ran aground, resulting in a huge oil spill along the costal areas of Karachi, Pakistan. The purpose of this study was to assess the lung function and follow up change after one year in subjects exposed to crude oil spill in sea water. It was a cross sectional study with follow up in 20 apparently healthy, non-smoking, male workers, who were exposed to a crude oil spill environment during oil cleaning operation. The exposed group was matched with 31 apparently healthy male control subjects. Pulmonary function test was performed using an electronic Spirometer. Subjects exposed to polluted air have significant reduction in forced vital capacity (FVC), forced expiratory volume in first second (FEV(1)), forced expiratory flow (FEF(25-75%)) and maximum voluntary ventilation (MVV) compared to their matched controls. This impairment was reversible and lung functions parameters were improved when the subjects were withdrawn from the polluted air environment.     

从深海花粉记录看末次冰消期寒冷阶段北大西洋东部反气旋环流的增强

极地高压以及与之有关的气团和能量从高纬度传送到低纬度可从理论上解释末次冰消期风力和气团途径的变化．我们在这里使用采自葡萄牙滨外和象牙海岸滨外两个岩心（编号为SU8118和KS84063；地点分别为37°46′N，10°11′W和4°23’80″N，4°11′W；水深分别为3135m和周05m）的花粉资料来证实这个理论并用文字确定这些大气交流变化的时间。两个钻位目前处于北部西风带和南部信风热带辐合区的影响范围。两个钻孔在未次冰消期的寒冷阶段（约在15ha冰消期开始阶段和10．3ha新仙女木期）记录下了相似的大气模式，均为花粉输入量增加和东北一…     

从大偏移距震源的垂直地震剖面法数据得到的西西伯利亚沉积的横波型首波

在上一篇文章里叙述了利用西西伯亚沙依姆油田罗文采油场的垂直地震剖面资料使用纵波型首波构制速度的剖面二篇文章则介绍用其横波型首波构造制该地区速度剖面的方法及研究结果。     

用三分量台站和台阵资料估计方位角和慢度

用NORESS台阵记录的短周期P波比较了用三分量台站和台阵估算方位角和慢度的能力。对垂直台阵的资料,方位角和慢度用宽带频率-波数(f-k)分析方法得到。对三分量资料采用偏振分析方法,应用NORESS公报中的波至时间和主频信息,资料处理是自动的。用NEIS(美国地震情报处)公报或区域台网公报的定位结果独立确定的方位角和/或慢度作参考。对100多个远震和区域事件进行了分析。它们是从各种不同距离、方位角和较大范围的信噪比(SNR)资料中挑选出来的。三分量台站估算方位角和慢度的能力很大程度上取决于资料的信噪比。大约在信噪比阈值为2以下的资料,对两个参数的估算结果分散都很大,对远震事件的慢度倾向于估计过高。并且三分量资料结果在NORESS台阵内依赖于位置而变化,用宽带f-k方法获得的台阵测量在一定信噪比水平上不受噪声的明显影响。对于具有足够信噪比的事件,两种方法都很好,但f-k方法更好一点。     

有限频率地震层析成像方法及研究进展

本文从基于射线理论的走时地震层析成像的发展引出有限频率地震层析成像, 说明两者最为本质的差别是有限频率灵敏度核函数。 概述了有限频率层析成像方法和基本原理, 详细阐述了国内外有关有限频率层析成像方法的研究进展和应用成果, 强调有限频率层析成像对全球地幔柱研究的重要意义, 最后指出有限频率层析成像方法在理论上的诸多优点目前还没有在实际应用中得到充分体现, 还存在一些问题需要解决。     

工程物探中地震层析成像的研究

从实际情况出发,讨论工程中应用地震层析成像方法几个环节中的一些具体问题,包括资料采集中观测系统的装置,原始资料的分析和预处理,以及资料处理时如何选择合适的参数等。文中提出的扫描法、快速搜索法等弯曲射线校正方法克服了以往方法计算量大、存在盲区等缺点。反演实测资料效果良好。     

应用接收函数方法研究海南及其邻区地幔转换带结构

利用海南、广东及广西区域台网和国家台网共88个宽频带地震台站记录的2007年8月至2010年3月75个远震事件波形资料,采用接收函数共面元叠加的方法,得到了海南及其邻区上地幔410 km和660 km间断面结构和转换带厚度.结果表明,研究区410 km间断面形态较复杂,局部下沉到447 km,而660 km间断面相对简单,其深度分布在670 km左右.海南岛东北部存在一个直径约200 km的转换带异常薄的区域,其厚度较全球平均值薄25±5 km,相当于转换带中存在约180℃的高温异常,转换带厚度局部偏薄暗示海南地幔柱可能起源于下地幔.     

PCB, PCDD/F and PBDE levels and profiles in crustaceans from the coastal waters of Brittany and Normandy (France)

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analysed in the muscle of various edible marine crustaceans (spider crab, edible crab, velvet swimming crab and Norway lobster) from the Brittany and Normandy coasts (France). The highest concentrations were measured in species collected from Antifer (Seine Bay). PCB and PBDE patterns in crustacean muscles were similar and independent of the geographical area with the predominance of the high chlorinated PCBs (CB153, 138, 118 and 180), and of a few PBDE congeners (BDE47, BDE99, BDE100 and BDE28). Oppositely, dioxin contamination differed with site. The major component in crustaceans from the Seine Bay was 2378-TCDF, whereas specimens from cleaner areas had higher relative concentrations of OCDD. Finally, the comparison of the spider crab contaminant profiles to those measured in mussel and sea bass highlighted two different trends: decapod crustaceans possess relatively strong capacity to metabolise PCBs and PBDEs; however these species might be used as bioindicators for dioxin pollution monitoring in the marine coastal environment.