等离子体层顶附近的电子浓度分布

本文处理了GEOS-2号卫星RS探测器所测得的磁层冷等离子体电子浓度资料,给出了电子浓度小时平均值的日变化,并分析了其月均值及年均值特征。发现在平均值的日变曲线中,电子浓度的极大值出现在1600LT,表明等离子体层突起的位置处于下午扇区。这一事实有利于磁层大尺度对流电场并不总是晨-昏指向这一观点。文中对电子浓度小时平均值的年均值日变曲线进行了拟合,给出了近似表达式,并计算了同步轨道上的积分电子浓度,其量级为10¹¹cm^-2。通过月均值和积分浓度的分析,发现同步轨道上的电子浓度存在季节变化。     

People’s perception and socioeconomic determinants of soil erosion:A case study of Samanalawewa watershed,Sri Lanka

Though soil erosion is an important concern in Sri Lanka, there is a dearth of baseline information on soil erosion in many ofits watersheds, which obstructs monitoring of soil erosion and mitigating its effects. In order to assess soil erosion in a critical watershed and to identify its determinants, the Samanalawewa watershed, which contains one of the main hydropower generating reservoirs in Sri Lanka, was selected for this study. Remote-sensing (RS) and geographic information system (GIS) based modeling...     

A survey of antifoulants in sediments from Ports and Marinas along the French Mediterranean coast

Due to deleterious effects on non-target organisms, the use of organotin compounds on boat hulls of small vessels (<25 m) has been widely prohibited. The International Maritime Organisation (IMO) resolved that the complete prohibition on organotin compounds acting as biocides in antifouling systems should commence in 2008. As a result of restrictions on the use of organotin based paints, other antifouling formulations containing organic biocides have been utilised. This survey was conducted to assess the contamination of replacement biocides in the marine environment following the ban of TBT-based paints. Surface sediments samples were collected in the major ports and marinas along the France Mediterranean coastline (Cote d’Azur) and analysed for organotin compounds, Irgarol 1051, Sea-nine 211^TM, Chlorothalonil, Dichlofluanid and Folpet. Every port and marina exhibited high levels of organotin compounds, with concentrations in sediments ranging from 37 ng Sn g⁻¹dry wt in Menton Garavan to over 4000 ng Sn g⁻¹dry wt close to the ship chandler within the port of Villefranche-sur-Mer. TBT degradation indexes suggested that fresh inputs are still made. Among the other antifoulants monitored, only Irgarol 1051 exhibited measurable concentrations in almost every port, with concentrations ranging from 40 ng g⁻¹dry wt (Cannes) to almost 700 ng g⁻¹dry wt (Villefranche-sur-Mer, ship chandler).     

Assessing estuarine environmental quality using fish-based indices: performance evaluation under climatic instability

The seasonal variation of five selected multimetric indices for the determination of the Ecological Quality Status (EQS) of transitional waters was evaluated, as well as the indices’ responses to an extreme drought event that occurred in 2005. The database used regards the Mondego River estuary, which was sampled from June 2003 to August 2006 on a monthly basis. Among the selected indices (EBI - Deegan et al. [Deegan, L., Finn, J.T., Ayvazlan, S.G., Ryder-Kieffer, C.A., Buonaccoesi, J., 1997. Development and validation of an Estuarine Biotic Integrity Index. Estuaries 30(3), 601-617], EDI - Borja et al. [Borja, A., Franco, J., Valencia, V., Bald, J., Muxika, I., Belzunce, M.J., Solaun, O., 2004. Implementation of the European Water Framework Directive from the Basque Country (northern Spain): a methodological approach. Marine Pollution Bulletin 48(3-4), 209-218], EFCI - Harrison and Whitfield [Harrison, T.D., Whitfield, A.K., 2004. A multi-metric fish index to assess the environmental condition of estuaries. Journal of Fish Biology 65, 683-710], EBI - Breine et al. [Breine, J.J., Maes, J., Quataert, P., Van den Bergh, E., Simoens, I., Van Thuyne, G., Belpaire, C., 2007. A fish-based assessment tool for the ecological quality of the brackish Scheldt estuary in Flanders (Belgium). Hydrobiologia 575, 141-159] and TFCI - Coates et al. [Coates, S., Waugh, A., Anwar, A., Robson, M., 2007. Efficacy of a multi-metric fish index as an analysis tool for the transitional fish component of the Water Framework Directive. Marine Pollution Bulletin 55, 225-240]), the EBI by Breine et al. (2007) was the only that evidenced clear interannual and seasonal variations. The EQS by the several indices ranged from “Low” to “High”, depending on the index considered, evidencing the high level of mismatch between indices. The results are discussed in the scope of the EU Water Framework Directive, regarding monitoring strategies, application of indices and EQS assessment.     

Spatial assessment of fishing effort around European marine reserves: implications for successful fisheries management

We examined the spatial dynamic of artisanal fishing fleets around five European marine protected areas (MPAs) to derive general implications for the evaluation of MPAs as fisheries management tools. The coastal MPAs studied were located off France, Malta and Spain and presented a variety of spatial designs and processes of establishment. We developed a standardized methodology to define factors influencing effort allocation and to produce fishing effort maps by merging GIS with geostatistical modelling techniques. Results revealed that in most cases the factors “distance to the no-take”, “water depth”, and “distance to the port” had a significant influence on effort allocation by the fishing fleets. Overall, we found local concentration of fishing effort around the MPA borders. Thus, neglecting the pattern of fishing effort distribution in evaluating MPA benefits, such as spillover of biomass, could hamper sound interpretation of MPAs as fisheries management tools.     

首钢工业区土壤剖面重金属含量及其结合态的磁指示作用的研究

对取自首都钢铁厂附近的土壤样芯进行了重金属含量、形态分析和的磁学测量.探讨了利用磁参数追踪和指示重金属污染和有机结合态和铁锰氧化结合态重金属的可行性.结果表明:土壤样芯中Cu、Pb、Zn、Fe和Mn的含量与χ、SIRM和ARM存在着十分相似的垂向变化特征,且相关关系显著(0.98>R>0.86).进一步对磁化率和Cu、Pb、Zn、Fe和Mn各结合态进行相关分析表明:五种元素的有机结合态与铁锰结合态和磁化率呈显著相关关系(0.98>R>0.56),而交换态和残渣态重金属与磁化率基本不存在相关关系.反映了磁性矿物和和重金属在赋存状态的本质联系.表明了磁性测量可作为工业区土壤重金属污染及有机结合态与铁锰结合态重金属记录信息提取的辅助手段.     

俯冲带火山下岩浆的形成、上升和存储的时间尺度

现在有足够的资料可用来尝试建立一个关于俯冲带火山下熔体的产生、迁移和存储的完整的模型。在喷发前的几十万年到少于一千年的时间里,都可以发生流体从俯冲的洋壳流到地幔楔中的现象。这支持了认为流体的加入是与部分熔融紧密相关的模型,但也有一些证据可以证明流体是降压熔融的结果。流体开始加入的时间可能与俯冲的速率(例如,水供应的速率)、俯冲的角度以及由此决定的地幔楔的热结构有关。相反,俯冲沉积物到俯冲带熔岩源区的贡献在喷发前大约35万年到4百万年的时候看来就发生了。沉积组分的部分熔融证据与短的流体迁移时间、斑晶平衡温度及其他观测结果的结合都指出,地幔楔在接近于俯冲板块边界上的地方具有相当高的温度。新的226Ra资料表明,在流体加入和火山喷发之间只有很短的时间。这就要求快速的熔体分凝、沿通道流动的岩浆上升过程以及在岩石层内最短的停滞时间。一般说来,在上升期间或者在岩浆房里,发生从玄武岩到安山岩的演化是快速的,这可以从一些有关地幔的地球物理资料来推断。矿物等时线资料表明,一些安山质岩浆后来停在了更浅的岩浆房中。它们可以在那里以几万年或更短些的时间尺度通过分异作用演化成英安质成分,通常都伴有同化作用。     

Toxicity of a secondary-treated sewage effluent to marine biota in Bass Strait, Australia: development of action trigger values for a toxicity monitoring program

Melbourne Water's Eastern Treatment Plant (ETP) produces a secondary-treated sewage effluent which is chlorinated and discharged into Bass Strait at Boags Rocks, Victoria, Australia. Disappearance of the sensitive brown seaweed Hormosira banksii from rock platforms immediately adjacent to the shore-line discharge was identified in the early 1990s. Subsequently, Melbourne Water and CSIRO undertook an environmental impact assessment and review of land and marine effluent disposal options, which included ambient water quality monitoring, biological monitoring, bioaccumulation studies and toxicity testing of existing effluent to assess the nature and magnitude of the environmental effects. This paper presents data from the toxicity monitoring programs since 2001. Chronic toxicity testing using macroalgal germination and cell division (H. banksii), microalgal growth rate (Nitzschia closterium) and scallop larval development (Chlamys asperrima), confirmed that ammonia was the major cause of effluent toxicity. Results from this toxicity monitoring program were used to develop action trigger values for toxicity for each species, which were then used in a refined monitoring program in 2005-2007. An upgrade of the ETP is in progress to improve nitrification/denitrification in order to reduce ammonia concentrations and the toxicity of the effluent. Toxicity testing with a simulated upgraded effluent confirmed that ammonia concentrations and toxicity were reduced. Estimated "safe" dilutions of effluent, calculated using species sensitivity distributions, decreased from 1:140-300 for existing ETP effluent to 1:20 for nitrified effluent, further confirming that treatment improvements should reduce the impact on marine biota in the vicinity of the discharge.     

Adsorption of tributyltin by tributyltin resistant marine Pseudoalteromonas sp. cells

The isolate, Pesudoalteromonas sp. TBT1, could grow to overcome the toxicity of tributyltin chloride (TBTCl) up to 30 microM in the absence of Cl(-) in the medium until the cells reached an exponential phase of growth. The viability, however, was reduced after the cells reached a stationary phase. The degradation products, such as dibutyltin (DBT) and monobutyltin (MBT), were not detected in the growth medium, indicating that the isolate has no ability to degrade TBT into less toxic DBT and MBT. Up to about 10(7.5) TBT molecules were adsorbed by a single cell. The observation of morphological changes with an electron microscope showed that the cell surface became wrinkled after exposure to the lethal concentration of 10 mM TBTCl. These results indicate that the resistance of the isolate toward the toxicity of TBTCl is not related to the unique cell surface, which seems to play an important role in preventing the diffusion of TBTCl into the cytoplasm.     

Geodynamic Technique Applied to the Volcanic Activity Forecast of Lanzarote Island in Spain

In accordance with the Agreement of Sino-Spain Science and Technology Cooperation,the Institute of Seismology,SSB of China and the Institute of Astronomy and Geodesy of Spain have together performed research at the Geodynamics Laboratory of Lanzarote(Canary Islands)with geodynamic instrumentation.Researchers conducted observation and then analyzed the data compiled.Researchers using the advanced geodynamic instruments could monitor the volcanic activity and seismicity in order to forecast the volcanic eruption and earthquakes.The results of this paper are obtained from this scientific and technological cooperation of the two institutes between China and Spain.