全文获取类型
| 收费全文 | 61篇 |
| 免费 | 7篇 |
| 国内免费 | 12篇 |
专业分类
| 测绘学 | 3篇 |
| 地球物理 | 9篇 |
| 地质学 | 44篇 |
| 海洋学 | 19篇 |
| 综合类 | 5篇 |
出版年
| 2024年 | 4篇 |
| 2023年 | 2篇 |
| 2022年 | 4篇 |
| 2021年 | 4篇 |
| 2020年 | 2篇 |
| 2019年 | 6篇 |
| 2018年 | 1篇 |
| 2017年 | 9篇 |
| 2016年 | 3篇 |
| 2015年 | 2篇 |
| 2014年 | 5篇 |
| 2013年 | 6篇 |
| 2012年 | 11篇 |
| 2011年 | 6篇 |
| 2010年 | 3篇 |
| 2009年 | 2篇 |
| 2008年 | 2篇 |
| 2007年 | 1篇 |
| 2006年 | 1篇 |
| 2005年 | 1篇 |
| 2003年 | 1篇 |
| 2002年 | 1篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1988年 | 1篇 |
排序方式： 共有80条查询结果，搜索用时 15 毫秒
41.
《Applied Geochemistry》1997,12(1):37-54
The Cadjebut MVT mineralization is hosted by carbonate-evaporite units in the Givetian lower dolomite sequence of the Pillara platform, northern Western Australia, and occurs as 2 ore types: (1) An early Zn-rich, stratiform and rhythmically banded ore and its laterally equivalent halo of banded marcasite, barite ± calcite; and (2) a later cross-cutting, breccia-fill, Pb-rich ore. The 2 ore types are exploited through 2 mining lenses; an upper lens 1 and lower lens 2. The orebody is sited N of the normal, basin-side down, Cadjebut Fault. Rhythmically banded marcasite completely envelopes the orebody in both lenses, whereas banded barite occurs N of the lower lens 2 only where the barite is partially to completely replaced by late cloudy calcite + marcasite. Barite replacement by marcasite and cloudy calcite increases northwards. Petrographic and trace element data indicate 3 types of Fe-sulfides: (1) low-Pb Fe-sulfides with Pb contents <5300 ppm; high-Pb Fe-sulfides with Pb contents <30 000 ppm and, extremely high-Pb Fe-sulfides with > 30 000 ppm Pb. Only the ‘colloform’ pyrites exhibit Pb contents above 30 000 ppm, and SEM images show these elevated Pb contents are due to micron-scale galena inclusions. Mineral chemical data from sulfides in the stratiform Fe-sulfide and barite halos indicate that main ore-stage fluids of the rhythmically banded ore event were enriched in Zn, Pb, Cd, As and, to a minor extent Ni and Cu. Late-stage fluids of the rhythmically banded ore event were not saturated with respect to galena, precipitating low-Pb marcasites along the very outer fringes of the orebody, and replacing rhythmically banded barite in lens 2. Only the low-Pb marcasites show various stages of pyrite inversion. Petrographic and trace element mineral chemistry of the 2 stratiform halos are best explained by a model in which main ore stage fluids of the early rhythmically banded ore event emanated from below the Cadjebut orebody along an inferred antithetic reverse fault. The presence of a laterally zoned alteration halo with a pattern of proximal higher Pb and trace element-bearing Fe-sulfides provides a vector towards the ore zone, and has important exploration significance for this style of base-metal mineralization. 相似文献
42.
东海盆地西湖凹陷花港组砂岩储层作为西湖凹陷的重要勘探目的层,储层非均质性研究至关重要,笔者等基于储层成岩作用和成岩演化分析,明确中央反转带南北差异,进一步分析其差异成因。研究结果表明,北部地区具有更强的压实作用和溶蚀作用,纵向上以3500 m和4000 m为界划分为酸性、酸碱过渡和碱性3个成岩带,经历两期硅质胶结和三期钙质胶结;而南部地区埋深浅、地温低,仅具有两期钙质胶结,纵向上以4000 m为界划分为酸性和碱性两个成岩带;由于北部地区具有更多的岩浆岩母源贡献使得储层抗压实能力较差,遭受压实更强,但烃源岩较强的生烃强度使得储层遭受溶蚀作用更强,因此北部地区花港组储层具有低孔高渗的特征。该研究对优质储层发育研究和甜点预测具有重要意义。 相似文献
43.
水平井分段压裂技术已在低渗透油气藏及煤层气开发过程中得到了较为广泛的应用,并取得了良好的经济效果。但是,由于分段压裂会使直井段的套管承受交变应力作用,进而造成其在软硬交错地层处发生严重变形,从而影响压裂安全作业,甚至引发所有剩余压裂段报废。为探索其破坏机理,开发一个类似弹簧单元的用户子程序来模拟循环荷载作用下套管-水泥环界面的受力情况,并将该单元植入到套管-水泥环-岩层系统的ABAQUS轴对称有限元模型中,模拟水平井分段压裂过程中套管的力学行为。结果表明,在软硬交错地层中,采用水平井分段压裂时,注入压力与地应力之间的交变应力差会造成套管的大变形。此外,基于ABAQUS的数值模拟结果,采用FE-safe评估套管疲劳寿命,发现处于软硬交错地层处套管的疲劳寿命最短。基于上述研究,建议在具有软硬交错地层的低渗透油藏及煤层气储层中进行分段压裂时,应设法提高非压裂阶段压力,以减轻交变应力对软硬交错地层处的套管损伤。 相似文献
44.
《Applied Geochemistry》1988,3(6):573-582
Detailed molecular and isotopic analysis of near surface liquid hydrocarbon seepage is useful not only in determining the presence of petroleum hydrocarbons but also to indicate the type and quality of deeper seated hydrocarbons. Near surface sediment bitumens collected over known production in the offshore Santa Maria basin were shown to be similar to reservoired petroleum in the adjacent onshore. Triterpane, sterane and aromatized sterane compositional similarities between oils and near surface sediment bitumens suggest a common source in the Monterey Formation. An empirical model based on the relation between oil composition (pristane/phytane and bisnorhopane/hopane ratios) and API gravity was applied to the near surface bitumens and accurately predicted the API gravity of the nearest known production. The improvement and refinement of geochemical prospecting techniques has greatly enhanced their use and reliability as exploration tools. 相似文献
45.
大地热流值是表征地球热状态的重要参数,也是进行深部地温预测和评价一个地区地热资源的最基本数据。受钻孔测温的影响,盆地外的无钻孔测温地区缺少实测的大地热流值。目前的热流分布图都是依据相邻盆地的实测值进行插值绘制的,无钻孔区热流值可信度较低。由于岩石居里点与温度密切相关,可以通过居里面深度来研究地表热流值。本文依据东北地区现有的居里面深度分布图,结合实测的岩石热导率、岩石生热率数据和相应的地壳分层状况,计算了东北地区的大地热流值,重新绘制了中国东北地区精细的大地热流分布图。东北地区整体大地热流处于42.5~95 mW/m 2 之间,热流高值位于五大连池及敦化 密山断裂带海龙—牡丹江一带,松辽盆地内部、小兴安岭和长春 延吉缝合带也有局部的高热流值。热流高值与居里面隆起区域有较高的一致性,即居里面隆起处热流较高,而坳陷区热流较低。本次研究填补了中国东部地区热流实测值空白,为该区深部地温预测和地热资源评价提供了更加准确的参数。 相似文献
46.
Vast parts of the Australian continent are prospective for precious and base metal mineralisation, but exploration is hindered by extensive cover of often deeply reaching regolith. New operational exploration methods are required that can help to characterise the cover and provide information about bedrock signatures. This paper shows how mineral mapping information from a combination of satellite multispectral Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery and drill core hyperspectral profiling data (HyLogging™) can be used to unravel the regolith stratigraphy and to describe regional variations of regolith landforms, delivering important information for mineral exploration.The case study is located in the Neale tenements in the northeastern Albany–Fraser Orogen (Western Australia), which is prospective for Tropicana-style gold mineralisation. By interpretation of indicator minerals from hyperspectral drill hole logging data the regolith stratigraphy atop a metamorphic basement, comprising saprock, ferrugineous saprolite, kaolinitic saprolite, silcrete and transported cover, is recorded in cm-detail. Important mineralogical parameters extracted from the hyperspectral subsurface data and validated by XRD and FTIR, are 1) the abundance and type of iron oxides, 2) the abundance and crystallinity of kaolinite, 3) the abundance and composition of primary minerals, such as white mica, and 4) the abundance of quartz.The HyLogging™ data served as ground control points for mineral mapping information provided by CSIRO's ASTER Geoscience Products, which are a collection of mineral maps that highlight variations in the abundance, type or chemistry of selected mineral groups. Key ASTER Geoscience Products for regolith characterisation were the Ferric Oxide and AlOH abundance and composition images. The comparison of the surface with the subsurface data suggests three major different regolith landforms, including erosional, depositional and relict areas, which were used to generate a map showing transported versus relict and erosional areas. Erosional domains were mapped out in great detail, providing important information for exploration in saprolite dominated areas. Furthermore, source areas of transported material could be identified, which may help to understand the distribution of geochemical signatures collected during, for example, geochemical soil sampling projects. 相似文献
47.
基于淮北矿区4个矿井共15块煤定向样品的镜质组反射率测试数据,在相容性调整的基础上,开展煤样镜质组反射率三维椭球体进行拟合。结合区域及采样地成煤后构造演化分析及煤样变形类型特征,深入研究煤镜质组反射率三维椭球体的方位和形状对应力、温度和变形结构的响应,并探讨其内在机理。结果显示:煤镜质组反射率三维椭球体最大—中间反射率所在平面的倾向多与区域应力来源方向相近,其原因可能归结于煤中芳香片层向垂直于岩石圈当中近水平构造应力和上覆地层压力的合力方向优势发育。垂直于挤压应力方向延伸的断层的干扰、煤变形程度和多期应力场的叠加效应是导致少数样品指示异常的主因。在多期应力场叠加影响区域,镜质组反射率定向会向后期应力方向发生不同程度偏转。但对于强变形构造煤,煤体颗粒间的移位旋转会削弱镜质组反射率重新定向偏转的程度,使其镜质组最大—中间反射率平面倾向主要指示前期应力来源方向。岩浆热异常是导致最大—中间反射率所在平面陡倾的主要因素之一。根据弗林参数,多数样品表现为扁椭球型,仅是煤正常演化的反映,而长椭球型则主要反映了岩浆热异常的的影响。 相似文献
48.
The present paper addresses the mechanical behavior of buried steel pipes crossing active strike-slip tectonic faults. The pipeline is assumed to cross the vertical fault plane at angles ranging between zero and 45 degrees. The fault moves in the horizontal direction, causing significant plastic deformation in the pipeline. The investigation is based on numerical simulation of the nonlinear response of the soil–pipeline system through finite elements, accounting for large strains and displacements, inelastic material behavior of the pipeline and the surrounding soil, as well as contact and friction on the soil–pipe interface. Steel pipes with D/t ratio and material grade typical for oil and gas pipelines are considered. The analysis is conducted through an incremental application of fault displacement. Appropriate performance criteria of the steel pipeline are defined and monitored throughout the analysis. The effects of various soil and line pipe parameters on the mechanical response of the pipeline are examined. The numerical results determine the fault displacement at which the specified performance criteria are reached, and are presented in diagram form, with respect to the crossing angle. The effects of internal pressure on pipeline performance are also investigated. In an attempt to explain the structural behavior of the pipeline with respect to local buckling, a simplified analytical model is also developed that illustrates the counteracting effects of pipeline bending and axial stretching for different crossing angles. The results from the present study can be used for the development of performance-based design methodologies for buried steel pipelines. 相似文献
50.