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21.
巴布亚新几内亚西部Fubilan山奥克泰迪矿床是一个世界级铜金矿床,在大地构造上位于新几内亚造山带的巴布亚褶皱带。该矿床的铜金矿化赋存于Fubilan二长斑岩及其周边的磁铁矿夕卡岩和硫化物夕卡岩中。矿石类型以原生硫化物矿石为主,金属矿物包括磁铁矿、黄铁矿、磁黄铁矿、白铁矿、黄铜矿、斑铜矿等。蚀变类型包括夕卡岩化、钾化、泥化和青盘岩化。矿床氧化次生富集带发育,表生矿石矿物为蓝辉铜矿、辉铜矿、自然铜、铜蓝和银金矿。成矿作用主要受区域构造、侵入杂岩体、Darai组灰岩地层、断裂等因素的控制。根据矿床的主岩、矿石特征、蚀变特征和控矿因素,认为该矿床成因类型属于较为典型的夕卡岩—斑岩型矿床。 相似文献
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催化臭氧化降解有机废水及影响因素 总被引:2,自引:0,他引:2
主要论述了自制的V-O型催化荆催化臭氧化降解有机废水的研究。试验表明,以TiO2,SiO2,ZrO2作栽体,在氮气或氧气中焙烧,而制得的6种催化荆中,V-O/SiO2/N2显示了较好的催化性能和活性;通过催化荆吸附试验和在反应体系中加入一定量的自由基猝灭荆,初步探讨了其催化机理,即催化荆和臭氧反应,生成了氧化性极强的羟基自由基;催化臭氧化时间、催化荆用量、进气臭氧浓度、体系pH值等因素均对降解产生一定的影响。 相似文献
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深海水道作为深水环境中重要的储层类型,具有极为丰富的深海油气资源,近年来一直是深海油田勘探和开发的重点区域,但对水道内部构型边界的识别刻画仍然是一个难点。依据三维地震数据以及测井和岩心资料,对西非X油藏水道进行了内部构型边界的精细划分,并分析了其水道演化模式。研究表明:区内水道体系边界可通过地震相特征差异进行识别,并将其分为限制性、半限制性和非限制性3种类型;复合水道边界可通过“垂向分期”和“侧向划界”原则进行确定;单一水道边界可通过水道边界振幅强弱变化进行识别,其在平面上有单侧向迁移和沿下游摆动迁移2种迁移模式,在剖面上单向侧向迁移段水道呈侧向迁移的特征,沿下游摆动段呈现出多期水道相互摆动切叠的特征;水道体系的演化可划分为初始形成、快速发育、平稳发育以及水道消亡4个阶段,对应一个完整的海平面变化旋回。 相似文献
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《Marine Policy》2015
While the notion of results based management has been devoted recent attention in the context of reforming European fisheries management, it remains unclear what it entails. A conceptual model of results based management in fisheries is proposed as a way for public authorities to delegate specific management and documentation responsibilities to resource users. The model comprises three defining features: (1) That authorities define measurable objectives for the utilization of fisheries resources; (2) that resource users are made responsible for achieving these objectives and for (3) providing documentation that allows for an audit of the extent to which they are met. Selected cases are used to illustrate these features. Rationales and prospects of introducing results based management as an alternative in a European fisheries management context are discussed, giving consideration to how it may be pursued under the reformed common fisheries policy. 相似文献
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The development of expulsion fractures in organic-rich shale is closely related to hydrocarbon generation and expulsion from kerogen. Organic-rich shales from the upper part of the fourth member and the lower part of the third member of the Paleogene Shahejie Formation in the Jiyang Depression, Bohai Bay Basin, East China, are used as an example. Based on thin sections, SEM and thermal simulation experiments, the characteristics of hydrocarbon generation and the conditions supporting the development of expulsion fractures were explored. The key factors influencing these fractures include the presence of kerogens, their distribution along laminae and around particle boundaries, their exposure to heat and the build-up in pressure due to confinement by low permeability. The development of excess pore fluid pressures and intrinsic low rock fracture strength are the main influencing factors. Pressurization by rapid generation of hydrocarbon provides impetus for fracture initiation and cause bitumen to migrate quickly. The shale laminae results in distinctly lower fracture strength laminae-parallel than laminae-normal and this directs the formation of new fractures in the direction of weakness. When pore fluid pressure increases, maximum and minimum principal effective stresses decrease by different proportions with a larger reduction in the maximum principal effective stress. This increases the deviatoric stress and reduces the mean stress, thus driving the rock towards failure. Moreover, the tabular shape of the kerogen aids the generation of hydrocarbon and the initiation of expulsion fractures from the tip and edge. The resulting fractures extend along the laminae when the tensile strength is lower in the vertical direction than in the horizontal direction. Particle contact boundaries are weak and allow fractures to expand around particles and to curve as the stress/strength regime changes. When pore fluid pressure fields at different fracture tips overlap, fractures will propagate and interconnect, forming a network. This paper could provide us more detailed understanding of the forming processes of expulsion fractures and better comprehension about hydrocarbon expulsion (primary migration) in source rocks. 相似文献
29.
Harmonic analysis, the traditional tidal forecasting method, cannot take into account the impact of noncyclical factors, and is also based on the BP neural network tidal prediction model which is easily limited by the amount of data. According to the movement of celestial bodies, and considering the insufficient tidal characteristics of historical data which are impacted by the nonperiodic weather, a tidal prediction method is designed based on support vector machine (SVM) to carry out the simulation experiment by using tidal data from Xiamen Tide Gauge, Luchaogang Tide Gauge and Weifang Tide Gauge individually. And the results show that the model satisfactorily carries out the tide prediction which is influenced by noncyclical factors. At the same time, it also proves that the proposed prediction method, which when compared with harmonic analysis method and the BP neural network method, has faster modeling speed, higher prediction precision and stronger generalization ability. 相似文献
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根据2018年秋季至2019年夏季4个季节的海滩剖面形态测量和表层沉积物粒度分析结果,研究了海阳万米海滩地形和表层沉积物粒度季节变化特征,探讨了控制研究区砂质岸滩季节性演化的因素。结果表明:连理岛-东村河口以西海滩剖面形态在强动力和弱动力条件下分别呈“上蚀下淤”和“下冲上塑”特征,夏季台风造成的滩肩侵蚀量大于冬季风,在滩面形成的沙坝数量多、规模小且离岸距离较之冬季风更远。连理岛-东村河口处海滩剖面形态整体呈淤积状态,且在强动力条件下的淤积量大于弱动力条件。连理岛-东村河口以东海滩剖面形态的季节性变化幅度小于以西海滩,同时滩肩顶剖面形态在夏季出现明显下凹特征。表层沉积物粒度特征变化同样呈现东西差异的特点,秋季到冬季,西侧海滩表层沉积物粒度变粗、分选变差,而东侧海滩变细、分选基本不变;冬季到春季,海滩表层沉积物粒度总体变细、分选较好;夏季变化趋势与冬季相似,但变化幅度有所差异。人工岛和港口等海岸工程建设是导致海滩剖面形态和表层沉积物粒度东西差异的主导因素;波浪和台风事件等是控制砂质岸滩季节性演化的主要动力因素;潮汐作用、旅游开发等人类活动也对岸滩演化造成一定影响。 相似文献