全文获取类型
收费全文 | 1440篇 |
免费 | 223篇 |
国内免费 | 137篇 |
专业分类
测绘学 | 20篇 |
大气科学 | 28篇 |
地球物理 | 758篇 |
地质学 | 695篇 |
海洋学 | 120篇 |
综合类 | 38篇 |
自然地理 | 141篇 |
出版年
2024年 | 13篇 |
2023年 | 46篇 |
2022年 | 38篇 |
2021年 | 43篇 |
2020年 | 59篇 |
2019年 | 76篇 |
2018年 | 59篇 |
2017年 | 98篇 |
2016年 | 81篇 |
2015年 | 65篇 |
2014年 | 76篇 |
2013年 | 94篇 |
2012年 | 91篇 |
2011年 | 111篇 |
2010年 | 102篇 |
2009年 | 83篇 |
2008年 | 64篇 |
2007年 | 87篇 |
2006年 | 74篇 |
2005年 | 74篇 |
2004年 | 41篇 |
2003年 | 39篇 |
2002年 | 35篇 |
2001年 | 23篇 |
2000年 | 19篇 |
1999年 | 28篇 |
1998年 | 30篇 |
1997年 | 27篇 |
1996年 | 30篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 21篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1800条查询结果,搜索用时 484 毫秒
121.
Paola De Rossi Fontanelli Luiz Fernando De Ros Marcus Vinicius Dorneles Remus 《Marine and Petroleum Geology》2009
The provenance of the Maastrichtian deep-water reservoir sandstones from the Jubarte oil field (Campos Basin, eastern Brazil), was studied using an integrated approach that included quantitative petrography, conventional heavy mineral analysis, garnet mineral chemistry and zircon geochronology. The reservoirs are predominantly coarse, poorly-sorted sandstones with feldspathic composition derived from uplifted basement terrains. The fourth- and fifth-order depositional sequences analyzed show no major variations in composition or in provenance through time. However, variations in apatite:tourmaline presents potential to be used as a parameter for sandstone correlation within the field. The composition of heavy minerals indicates derivation from high temperature and low-to-medium pressure aluminous metapelitic rocks, from granites and subordinate mafic rocks, derived from the Cabo Frio Tectonic Domain and the Oriental terrain of Ribeira orogen, characterizing a supply route from SW to NE. The low ZTR index, as well as the absence of low-grade stable heavy minerals and of metasedimentary rock fragments, suggest that by the end of Cretaceous all supracrustal, low-grade terrains had already been totally eroded, and that plutonic, infracrustal rocks were exposed, similarly to the present situation. 相似文献
122.
To unravel the mystery of the relationship between evaporates, Ca–Cl brines and accumulations of oil and N2 in the basins of ancient cratons, their N2, CH4 and He concentration ratios, as well as the isotopic composition (δ15N, δ13C and 3He/4He) were compared within the Volga-Ural basin. The study allowed subsalt fluids from Volga-Ural Basin to divide into two genetic groups. The first one is found within the basin's platform area. It includes Ca–Cl brines, high-viscosity heavy oil, bitumen and N2, which has concentrations higher than that of CH4 and positive values of δ15N. The second one is tied to the edge of the platform, the Ural Foredeep and Peri-Caspian Depression. In this group, only the oil and gas reservoirs, which have more CH4 than N2, and possibly negative values of δ15N, were discovered. Interaction of gas components in compared fluids indicates great role of degassing in the formation of their composition. It is suggested that the fluids of the first group (N2 > CH4) is what remains, and the second group (N2 < CH4) is what is disappears from the rocks during their metamorphism and degassing. 相似文献
123.
The Basque–Cantabrian Basin (NE Spain) has been considered one of the most interesting areas for hydrocarbon exploration in the Iberian Peninsula since the 60th to 70th of last century. This basin is characterized by the presence of numerous outcrops of tar sands closely associated with fractures and Triassic diapirs. The aims of this work is to establish the diagenetic evolution of the Upper Cretaceous reservoir rocks with special emphasis in the emplacement of oil and their impact on reservoir quality. The studied rocks are constituted of carbonates and sandstones that contain massive quantities of bitumen filling vugs and fractures.Petrographic results indicate that the carbonate rocks from Maestu outcrops are bioclastic grainstones and wackestones, whereas the tar sandstones from Atauri and Loza outcrops are dominated by quartzarenites and subordinated subarkoses. The paragenetic sequence of the main diagenetic phases and processes include, pyrite, bladed and drusy calcite cement, calcite overgrowths, silicification of bioclasts and microcrystalline rhombic dolomite cement, and first stage of oil emplacement, blocky calcite cement, coarse crystalline calcite cement, calcitized dolomite, calcite veins, saddle dolomite and stylolites filled by the second phase of oil entrance. Together with the above mentioned diagenetic alterations, the arenites are affected by early kaolinitization of feldspars and the scarce formation of clay rim and epimatrix of illite. All sandstones and dolomitized carbonate rocks show high intercrystalline and intergranular porosity which is full by biodegraded hydrocarbons (solid bitumen). The biodegradation affects alkanes, isoprenoids and partially hopanes and steranes saturated hydrocarbons. Aromatics hydrocarbons, like naphthalenes, phenanthrenes, dibenzothiophenes and triaromatics are also affected by biodegradation. Results indicate that the first HC emplacement corresponds to early stage of calcite and dolomite cementation, and the second and more important emplacement is related to fracturation processes resulting in the formation of excellent reservoirs. 相似文献
124.
本文在简要介绍三峡重庆库区基本情况的基础上,分析了库区生态问题,科学合理地提出了重庆库区生态监测的布站原则、站点选择、监测方式、监测项目和监测方法,为三峡库区生态监测进行了前瞻性的研究. 相似文献
125.
滑坡灾害的易发性评价方法和模型有很多,不同的学者又对其进行了不同的改进,形成了不同的方法。究竟哪种方法更好,还需要结合实际进行方法的比较分析。论文应用基于专家经验值的二元统计法分析了四川平武高坪铺库区(约32 km2)高程、岩性、与居民点距离、与河流距离、坡度和坡向6种因素对滑坡灾害影响,并在此基础上进行了滑坡易发性评价。 相似文献
126.
127.
岩性油藏地震描述技术在准噶尔盆地春光油田的应用 总被引:1,自引:1,他引:0
准噶尔盆地春光油田新近系沙湾组岩性油藏埋藏浅、厚度薄、成岩作用差,勘探效果不理想。利用层拉平切片技术确定有利储集相带、分频技术雕刻砂体、"类亮点"特征检测流体、进一步采用拟声波+电阻率反演两步法鉴别流体,这一技术方法系列在春光油田的实际应用效果良好。用拟声波+电阻率反演两步法可以检测出无亮点特征的含油砂体或含水砂体。对于不具备"类亮点"特征的滩坝砂油藏的勘探,可由原来的应用"类亮点"特征直接找油转为寻找有效圈闭,并在此基础上应用合适的流体检测技术,这同样可以发现有利的滩坝砂油藏。 相似文献
128.
中国海相油气田勘探实例之十三 塔里木盆地东河塘海相砂岩油田勘探与发现 总被引:3,自引:1,他引:2
东河塘油田位于新疆库车县,构造上隶属于塔里木盆地塔北隆起轮台凸起东河塘断裂构造带,是我国发现的第一个高产高丰度海相砂岩油田,它的发现是中国海相砂岩油气勘探理论和实践的一次重大突破。油田发现于1990年7月,至1994年探明石油地质储量3323.13×104t,天然气地质储量15.5×108m3,至2009年底累计产原油825.75×104t。石炭系东河砂岩油藏是东河塘油田的主体,其储层东河砂岩段是一套滨岸相砂体,具有厚度巨大、埋深大、储集性能好的特点;其油藏类型为块状底水背斜油藏,产能高,储量丰度高。论述了东河塘油田勘探与发现的历程,剖析了取得勘探成功的实践认识与意义。 相似文献
129.
130.