全文获取类型
收费全文 | 131篇 |
免费 | 12篇 |
国内免费 | 35篇 |
专业分类
测绘学 | 1篇 |
地球物理 | 11篇 |
地质学 | 156篇 |
综合类 | 2篇 |
自然地理 | 8篇 |
出版年
2024年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 9篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有178条查询结果,搜索用时 0 毫秒
1.
淮南煤田地下水类型及其特征 总被引:2,自引:0,他引:2
淮南煤田为全隐蔽煤田,松散层厚度大,主要含煤地层为二叠系。通过大量的勘探资料及生产矿井的开采成果,对影响煤层开采的地下水进行了分类,并对其水文地质特征进行了阐述,为新区的建井与开采提供了参考资料和决策依据。 相似文献
2.
3.
从淮南谢—矿五层煤(C_(13)、B_(11b)、B_(10)、B_(4b)和A_3)中精选出镜煤、壳质暗煤、惰性暗煤及构造煤,采用重量法,分别测定它们的甲烷吸附量,从而研究不同成分组成的煤其甲烷吸附性能。 相似文献
4.
疏降地下水引起地面塌陷浅析--以淮南煤矿区为例 总被引:4,自引:0,他引:4
以淮南西部矿区为例,介绍了该地区自20世纪60年代开采煤矿以来,由于疏降地下水,引起的地面塌陷。为了研究灰岩水动力场规律,先后在该区进行多时段、多水平放水试验。研究表明,覆盖粘土层、岩溶及人工疏降地下水,是该地区岩溶塌陷形成的基本条件。通过对粘土盖层性质、疏降地下水岩溶塌陷演化过程及塌陷机理与对应阶段过程综合分析,结合区域地质条件,掌握了塌陷点的分布规律。对目前西部地区塌陷“复活”、整治及未来城市规划,提出了建设性建议。 相似文献
5.
淮河以北矿区地面沉降及其成因 总被引:1,自引:0,他引:1
根据多年的高程实测资料,查明了淮河以北矿区(主要是潘集地区)地面沉降的幅度、速率及范围;分析了该区地面沉降的内因和外因,为区内地面沉降的防治提供了依据。 相似文献
6.
The No. 6 Coal-bed from the Heidaigou Mine, Jungar Coalfield, Inner Mongolia is a super-large Ga deposit. The dominant carrier of Ga is boehmite in coal. The study of coal facies may provide genetic enrichment information of Ga and its carrier (boehmite) in the Ga deposit. On the basis of study on coal petrology and mineralogy, it was found that the No. 6 Coal-bed from the Heidaigou Mine of Jungar was enriched in inertinites and the microlitho-types were dominated by clarodurite. The maceral morphological features and association indicate that the coal-bed was formed in a dry sedimentary environment or in a periodic dry sedimentary environment caused by the alternating variations of groundwater level. The optimum conditions for the enrichment of Ga and its particular carrier (boehmite) were dominated by four transitional conditions (1) the upper delta plain which was the transitional zone between alluvial and lower delta plains, (2) the transitional zone between the dry and wet forest swamps, being slightly apt to the dry one, (3) the transitional tree density between the thick and loose ones, and (4) the low moor that was the transitional zone between two high moors during peat accumulation. 相似文献
7.
Tatyana K. Dimitrova Erwin L. Zodrow Christopher J. Cleal Barry A. Thomas 《Geological Journal》2010,45(4):388-396
The palynology of clastic samples from seven stratigraphical levels in the late Moscovian Sydney Mines Formation, exposed along the shore at Bras d'Or, Nova Scotia, has been investigated. Most of the samples were from roof shales of major coals; the one sample that was not yielded a much higher proportion of pollen derived from extra‐basinal vegetation. The four stratigraphically lower roof shale samples yielded essentially similar palynological spectra, with 39 ± 4% lycophytes, 9 ± 4% sphenophylls, 23 ± 4% tree‐ferns, 12 ± 4% other ferns and 5 ± 3% cordaites. The palynology of the upper part of the investigated succession suggests a shift in vegetation towards one favouring more marattialean tree‐ferns, cordaites and conifers, and fewer lycophytes. This correlates with changes in drainage patterns as the alluvial plain migrated seawards and thus changed water tables. No evidence was found to suggest significant climate change at this time. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
8.
Dawei Lv Jitao Chen Zengxue Li Guiqiang Zheng Cuiyu Song Haiyan Liu Yanru Meng Dongdong Wang 《Resource Geology》2014,64(4):332-345
The Huanghebei Coalfield, one of the coal production bases in North China, was considered as a coalfield without coal‐bed methane (CBM) during past decades. In recent years, however, CBM has been discovered in coal‐bearing successions. In order to understand the CBM geological characteristics and accumulation process in this area, fifteen coal samples were collected and analyzed with respect to coal maceral and reflectance. The result shows that the gas distribution is uneven and the content varies in different areas even for the same coal bed. The storage of CBM is affected by geological factors such as burial depth, geological structures, and magmatic intrusion, among which the former two are more important in the formation of CBM. Deep burial of coal beds with the presence of cap‐rock mudstone can seal CBM. The CBM is also accumulated and preserved at the place where normal faults are distributed. Magmatic intrusion causes contact metamorphism and controls the CBM formation by heating the coal‐bearing successions. The obtained data indicate the geological conditions in northeastern Zhaoguan Mine are preferable for CBM formation and conservation; recent exploration estimates the CBM geological reserves up to 282.16 Mm3 and average of reserve abundance at 0.1662 × 108 m3 km?2. The Changqing Mine is a potential prospect in terms of CBM exploration since its geological conditions (structures and burial depth) are similar to the Zhaoguan Mine and its cap rock is even better. 相似文献
9.
10.
采取多种手段相结合的研究方法,对山东兖州煤田16号煤层的成煤植物进行了详细的研究。研究了16号煤层中的煤核植物群,还通过孢粉分析及分散角质层的研究,对成煤植物群及其在垂向上的演化进行了细致的研究。结合煤岩光片中煤植体的研究,并对照煤系地层大化石所反映的成煤期前后的植物群面貌恢复了16号煤层的成煤植物群。分析并讨论了上述研究方法在反映成煤植物及其演化方面的作用,认为只有通过这种综合研究才可以较准确地反映成煤植物群面貌及其在成煤过程中的变化。 相似文献