Effects of prolonged exposure to 4-tert-octylphenol on toxicity and indices of oestrogenic exposure in the sand goby (Pomatoschistus minutus, Pallas)

Alkylphenolic compounds are present in estuarine and marine environments. They are moderately bioaccumulative, and oestrogenic to fish following three week, in vivo, exposures. The effects of prolonged exposure are, as yet, unclear. Sand goby (Pomatoschistus minutus) were exposed to measured concentrations of 4-tert-octylphenol (OP) in a 28-day, dose-ranging study, and a six month temporal response study. Following 28-days exposure to measured 31+/-6 or 101+/-47 microg l(-1) OP (mean+/-SD), immature male sand goby showed elevated vitellogenin (VTG) mRNA expression. Plasma alkali-labile phosphate concentrations were elevated in both sexes and were higher in females than males. Although measured OP concentrations were variable, they were significantly different for each treatment and a range of concentration-dependent effects were observed. The LC(50) for chronic OP exposure (8 weeks) was 29+/-6 microg l(-1), and both sexes demonstrated concentration and duration dependent increases in VTG mRNA expression. Exposure to 28+/-20 microg l(-1) OP (median+/-95% CI) for 6 months inhibited development of male nuptial colouration and sperm duct glands. These findings are discussed in relation to environmental concentrations of alkylphenols and ecological concerns.     

Long-Term Landscape Evolution of the Northparkes Region of the Lachlan Fold Belt, Australia: Constraints from Fission Track and Paleomagnetic Data

Apatite fission track thermochronology (AFTT) and paleomagnetic (PM) results have been used to constrain the Late Paleozoic to Cenozoic landscape evolution of the Lachlan Fold Belt (LFB) around the Northparkes copper-gold deposit in east-central New South Wales. The present-day landscape of this region of the LFB is relatively flat with little expression of the underlying rock and has previously been interpreted to indicate long-term stability of the region since the end of LFB orogenesis in the Early Carboniferous. This was presumably borne out by PM analyses from thick weathered horizons within open pits at the mine, which suggested that significant periods of weathering, and hence relative landscape stability, prevailed during the Early to middle Carboniferous and at some time during the Cenozoic. Results from AFTT analyses, however, indicate that the region must have experienced significant episodes of cooling/denudation during the mid-Permian to mid-Triassic and during the early Cenozoic, as well as episodes of heating/burial during the Late Carboniferous to mid-Permian and during the late Mesozoic. When combined, the AFTT and PM results are in fact consistent and indicate that since the late Paleozoic the landscape of the LFB around the Northparkes deposit has evolved through multiple episodes of denudation and deposition as well as periods of relative stability during which the thick weathering horizons formed. Together these results establish a complementary chronological framework that constrains the Late Palaeozoic to Cenozoic landscape evolution of the Northparkes region and highlights the importance of using dual data sets in elucidating the long-term landscape evolution of similar "stable" terranes.     

热力暗挖隧道工程施工新技术

本文通过在北京第三使馆区热力浅埋暗挖隧道工程施工中所采用的大管棚支护,插筋喷砼补强护面处理,地面深孔注浆及隧道结构防水和降水等技术,介绍了在松散软弱土质地层进行浅埋暗挖施工的一些成功经验,在此撰文以供工程之参考。     

截水帷幕技术在元宝山露天煤矿的应用与效果评价

内蒙古元宝山露天煤矿是国内外罕见的特大富水型露天煤矿,为解决多年疏干排水造成的生产成本高和环保风险大等问题,拟采用截水帷幕技术对矿坑渗流补给通道进行帷幕截流。通过分析矿坑水文地质和工程地质条件,提出弧形半封闭落底式帷幕与群井疏干水力帷幕相结合的地下水控制方式,采用防渗膜垂向隐蔽叠覆铺设与抗渗混凝土充填工艺,在矿坑高程+452 m平盘开展帷幕试验研究,建造一座平面长度1 369 m、平均深度29 m、有效厚度大于0.8 m、底部嵌入基岩面3 m的截水帷幕。试验研究过程中,确定了元宝山露天矿的截水帷幕工艺,获得其单幅槽段开挖长度(14 m)、护壁泥浆密度(1.05~1.25 g/cm3)和防渗膜叠覆宽度(1 m)等主要技术参数,提出防渗膜水下磁吸式连接技术,通过加装磁条,利用阴阳磁吸原理实现防渗膜叠覆处的水下自粘连。试验工程结束后,通过取心验证、流场分析和流量变化等方法检验帷幕墙的质量和截水效果。结果表明:混凝土浇筑充填连续、密实;墙体内外水位差已达15 m以上;盲沟补给流量消失,截水效果显著。试验研究证实截水帷幕技术适用于元宝山露天煤矿,为后续工程开展提供了关键技术参数,完善了我国露天煤矿截水帷幕技术体系。      

Improvement of pollutant drift forecast system applied to the Prestige oil spills in Galicia Coast (NW of Spain): development of an operational system

An integrated system named METEOMOHID, developed by MeteoGalicia in the first stage of the Prestige accident in November 2002 was used successfully in an operational form to support decision making and assist in recovering tasks. Afterwards, METEOMOHID has been enhanced with the aim of developing an operational oceanography system to be used in the NW of the Iberian Peninsula. The METEOMOHID system includes local area hydrodynamic coastal ocean modelling (MOHID), real time atmospheric forcing from a local meteorological model (ARPS). Using the available data from the Prestige crisis, a set of simulations were designed in order to reproduce the oil spill drift. The implementation of a detailed vertical resolution in the model has allowed obtaining a detailed surface dynamic, improving our knowledge of the behaviour of tarballs into the water column. Thus, the wind-driven Eckman drift, the direct dragging of the wind were detached, and the possible existence of subsurface oil was assessed. In addition, the present work evaluates the effects of introducing climatologic large scale currents in the METEOMOHID system.     

Impact of light regimes on productivity patterns of benthic microbial mats in an antarctic lake: a modeling study

Filamentous cyanobacteria often dominate benthic microbial communities of antarctic lakes and usually exhibit saturation of photosynthesis at light intensities approximately 100 microEinst m-2 s-1. Incident light regimes are controlled by ice and snow accumulations overlaying water columns during much of the year. Thus, light availability to microbial mats is often below saturation intensity and is strongly influenced by modest changes in climatic factors. A model of net primary production for benthic mat communities of the subantarctic Sombre Lake, Signy Island, was developed (1) to evaluate depth-specific productivities of mat communities, (2) to test the relative importances of model parameters to mat production, and (3) to explore the potential impacts of climate change on mat production as manifested through changes in light regime. Simulated rates of net primary production corresponded to observations on a daily basis (approximately 1-4 micrograms C fixed mg-1 ash-free DW of mat d-1) but were an order of magnitude lower than estimates of net annual production based on field measurements (< or = 3 vs. 11-45 g C m-2 yr-1, respectively). Close examination suggested that the simulated values were more plausible. A detailed sensitivity analysis of model behavior revealed that variations in the time of ice and snow melt in spring accounted for 40-60% of the total variation in model behavior, emphasizing the importance of climatic factors to net primary production of mat communities and the sensitivity of mat production to climate change.     

深呼吸小城绿色发展报告暨“美丽中国·深呼吸小城”预备名单发布

<正>本刊讯记者宫建郭英杰中国国土经济学会围绕“深呼吸幸福感”理念进行连续十年的科普传播、科研评价、生态责任共同体共建活动。十年来,来自学术层的积极响应,来自基层的热情呼应,态势逐渐升温。去年7月中旬,国家航天局通过官网面向全社会公开征集碳监测卫星名称,“深呼吸号”入围了各地网民踊跃投票出的候选名称。     

非均质介质中地下水流动与溶质运移模拟——问题与挑战

对大空间尺度和长时间跨度的地下水流动及污染物质运移进行预测的需求, 使水文地质研究面临异乎寻常的挑战.这些需求来自于对核废料地质储放方法的安全性评价、地下水污染状况评价及其治理方案的选择.流动系统的非均质性是地下水流动及物质运移模拟中最主要的困难之一, 这种困难来自对非均质系统进行特征描述(通过原位观测实现)、概念化及模拟.评述了非均质介质中流动运移模拟的一些重要问题与挑战, 讨论了解决的途径.讨论的主题包括: 动力流动的沟道化, 示踪剂穿透曲线, 裂隙岩石中流体流动的多尺度, 观测的不同尺度, 模拟、预测与非均质性以及系统特征描述和预测性模拟的分析.