南沙海区中生界岩相分布及构造特征

为了了解南中国海南部南沙群岛陆架-陆坡区中生代地层发育情况,作者通过综合分析该海区钻井、拖网及1987年以来采集的20000多公里的多道反射地震勘探等资料,得到了对该区中生界基本特征的如下新认识:空间分布上,南沙的中生界具有从北部的郑和-礼乐隆起南缘向南增厚的趋势;沉积岩相方面,东部三叠纪时为深海相,侏罗纪为浅海与三角洲相,白垩纪为浅海-内浅海相,而往西南部中生代的海水深度有变深的趋势;中-新生代变形上,在南沙西部的曾母盆地,中生界褶皱为复式的、非协调性的,南沙中部多为舒缓褶皱,东部仅在近巴拉望海槽地带出现小幅度的褶皱。结合围区中生界及特提斯构造域的发育特征,作者提出南沙地块上的海相中生界在大地构造上归属于残留在中特提斯洋北部减薄陆缘地壳上的中特提斯期海相沉积地层,是该海域油气资源勘探不可忽视的对象。     

A finite differences formulation for the linear and nonlinear dynamics of 2D catenary risers

A finite differences (FD) solution method is proposed for the numerical treatment of the dynamic equilibrium problem of 2D catenary risers. The method is based on the so-called Box approximation, which in the scope of the present contribution is applied to the complete nonlinear model as well as to the reduced linearized formulation. The application of the Box method transforms the original governing systems into convenient sets of algebraic equations, which in turn are solved efficiently by the relaxation method. Extensive numerical calculations are presented that describe the dynamic behaviour of the structure and evaluate the amplification in loading due to the dynamic components. The effect of the geometric nonlinearities is assessed through comparative calculations that concern both mathematical formulations examined in the present, i.e. the complete nonlinear, and the reduced linearized model. Special attention is paid to the heave excitations as they amplify significantly the magnitudes of the loading components.     

养殖水体环境参数随潮汐变化特征及相关性分析——以湛江特呈岛东近岸海域为例

利用2018年4-5月在湛江特呈岛东边海域养殖区内测定的数据,以及海事服务网提供的潮汐数据,分析了研究区域潮汐、流速和流向的变化规律,研究了溶解氧(Dissolved Oxygen,DO)、化学需氧量CODMn(Chemical Oxygen Demand)、二氧化碳CO2浓度和pH等海水环境参数随潮汐变化的特征以及相关性,建立了分别利用DO和pH值来估算海水CO2浓度的新算法,平均估算精度分别达到90%和95%。分析结果表明:(1)研究区域呈现不规则半日潮,流速随潮汐变化分为正相关和负相关两种类型;流向随着潮汐变化基本是东南与西北向;(2) CODMn的变化完全取决于涨落潮过程,涨潮时CODMn值逐渐下降,而落潮过程CODMn值逐渐上升;(3) CO2浓度呈现出明显的日变化,在午后数值达到最低值,不完全受制于潮汐过程的控制;(4) DO和pH两者的变化趋势高度一致,其变化过程与CO2浓度变化过程正好相反;(5)同一地点的海洋环境参数随潮汐涨落有很大的变异性,因而在进行空间大面海洋环境参数调查时,用某时刻的值代表该点的全天情况会出现较大的误差。     

三种海洋硅藻胞外多聚物形态、微细结构及组成的初步研究

利用光镜和扫描电镜对厦门近海三种常见附着硅藻——爪哇曲壳藻亚缢变种(Achnanthes javanica var．subconstricta)、咖啡形双眉藻(Amphora coffeaeformis)和多枝舟形藻(Nav-icula ramosissima)胞外多聚物(Extracellular polymeric substances,EPSs)的形态和微细结构进行了研究,并初步分析了其化学组成。结果表明,A．javanica var．subconstricta的胞外多聚物为透明的长柄,分为领、柄及垫状物三部分,电镜显示其徽细结构为由许多纤维组成的双层实心管;Amphora coffeaeformis分泌的EPS为由串连的小节组成的实心管状结构,许多管交织成厚的胶质块;Navicula ramosissima的EPSs则为透明的薄膜并形成胶质膜。三种硅藻胞外多聚物的水溶性和水不溶性的主要成分均为多糖类,达总量的70％以上,蛋白质含量次之．不含脂类物质,但不同藻类EPS的组成差异较大。此外,还探讨了EPSs的功能及其分泌机理。     

基于逆散射级数法的鬼波压制方法

鬼波问题是影响海上地震资料分辨率和保真度提高的最重要因素之一.详细论述了逆散射级数理论和逆散射级数法鬼波压制原理,说明了逆散射级数方法进行鬼波压制理论的完善性和对鬼波描述的精确性.实现了基于逆散射级数理论的鬼波压制方法,方法以波动方程和Lippmann-Schwinger方程为基础,在频率-波数-波数域内构造与鬼波相关的压制算子,在不需要对地下介质作任何假设条件下实现地震数据驱动鬼波压制,并通过改善消除鬼波的压制算子,提高算法的稳定性.资料处理试验与处理结果分析表明,基于逆散射级数鬼波压制方法能在实现鬼波压制的同时较好保留有效反射波的信息,从而补偿地震资料低频损失和提高地震数据的保真度.数据处理试验还表明,研究方法能对低信噪比的地震资料进行有效的鬼波压制处理.建立了基于逆散射级数鬼波压制处理流程.     

The fisherly imagination: The promise of geographical approaches to marine management

The management of the sea has increased exponentially in the last half-century, and different academic disciplines have been vital in shaping this management. Human geography, despite its explicit focus on the human–environment nexus, has so far had little impact on human relations with the sea. Based on empirical research conducted in England and Scotland, we argue that human geography is uniquely placed to offer effective solutions to marine resource management problems, and that geographers have the potential to offer key insights into how human populations can best interact with the living seas. Three of the most important current scholarly ‘imaginations’ of the sea, and the policies they inform (economics and market-based management, conservation biology and area based protection, and anthropology and community management), are outlined. A potential ‘geographical imagination’ of the sea, drawing on key themes in contemporary scholarship is then presented, and grounded in empirical research. It is argued that human–ocean relations should be a key feature of geographical research agendas.     

A land controlled‐source electromagnetic experiment using a deep vertical electric dipole: experimental settings,processing, and first data interpretation

A multichannel borehole‐to‐surface controlled‐source electromagnetic experiment was carried out at the onshore CO₂ storage site of Hontomín (Spain). The electromagnetic source consisted of a vertical electric dipole located 1.5 km deep, and the electric field was measured at the surface. The subsurface response has been obtained by calculating the transfer function between the transmitted signal and the electric field at the receiver positions. The dataset has been processed using a fast processing methodology, appropriate to be applied on controlled‐source electromagnetics (CSEM) data with a large signal‐to‐noise ratio. The dataset has been analysed in terms of data quality and repeatability errors, showing data with low experimental errors and good repeatability. We evaluate if the induction of current along the casing of the injection well can reproduce the behaviour of the experimental data.     

The marine and coastal access act—A hornets' nest?

The Marine and Coastal Access Act 2009 is now enacted into law. This paper looks at predictions made about new law by one of the authors, Peter Jones, in his paper The Marine Bill: Cornucopia or Pandora's Box [1] and assesses how successful the Act has been in turning aspirations into law. The paper focuses on the following areas: ecosystem protection, stakeholder engagement, marine spatial planning and the provision of a network of highly protected marine reserves, and raises concerns that the ecosystem approach has progressively been dropped in the drafting process of the legislation. Concerns are raised that the new Inshore Fisheries and Conservation Authorities have similar inherent conflicts of interest to those exhibited by Sea Fisheries Committees, which they sought to replace. The effectiveness of marine planning is questioned, as there appear to be inbuilt loopholes for public authorities to avoid complying with the marine plans. The draft marine policy statement (MPS), published in July 2010, includes appropriate environmental safeguards, but the MPS has not yet been formally adopted. The absence of a concrete target for highly protected marine reserves means there is a danger that designations under the Act may have little effect on the ground. In conclusion the Act provides some new mechanisms for marine protection, but arguably does not yet provide a framework for implementing the ecosystem approach and is not an end in itself.     

Predicting copper toxicity in estuarine and marine waters using the Biotic Ligand Model

The Biotic Ligand Model (BLM) has proven efficient in predicting the toxicity of a variety of metals to freshwater organisms. Consequently, the US EPA has proposed its use for calculating freshwater copper criteria. This study evaluates the BLM for use in estuarine and marine waters. Studies were conducted using the bivalve, Mytilus sp. and 48-h embryo-larval development chronic estimator test methods. These are the most sensitive taxa and test in the US EPA saltwater copper criteria database. Samples from five locations around the USA were tested. There is a strong relationship between measured and BLM predicted copper EC50s (log transformed data, r² = 0.76, p < 0.001, n = 44). The BLM predicted within a factor ±2 of measured EC50s in 41 of 44 cases. However, the BLM tends to predict lower EC50s when measured EC50s are approximately 10 μg Cu/L. This may be due to limitations of the metal-dissolved organic matter interaction model.     

滇南勐野井钾盐矿床成因新解

勐野井钾盐矿床的成因,众说纷纭.笔者将此矿床和兰坪思茅坳陷沉积盆地的演化与板块构造活动相结合,提出侏罗纪古钾盐矿经再溶蚀、再沉积、再改造的成因假说.认为今后在兰坪思茅坳陷探盐找钾的新方向是深埋在地下的中侏罗统和平乡组及下侏罗统,有可能在此层位找到大型或超大型的海相固体古钾盐矿床.