首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   59篇
  免费   3篇
  国内免费   6篇
测绘学   2篇
地球物理   8篇
地质学   31篇
海洋学   19篇
天文学   1篇
自然地理   7篇
  2023年   3篇
  2022年   2篇
  2021年   4篇
  2020年   2篇
  2018年   2篇
  2017年   2篇
  2016年   5篇
  2015年   4篇
  2014年   2篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2010年   3篇
  2009年   5篇
  2008年   2篇
  2006年   4篇
  2005年   2篇
  2003年   5篇
  2002年   2篇
  2001年   2篇
  2000年   2篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1990年   1篇
  1982年   1篇
  1981年   1篇
  1977年   1篇
  1967年   1篇
排序方式: 共有68条查询结果,搜索用时 15 毫秒
11.
Both Pinghu and Huagang formations are important hydrocarbon reservoirs of the Xihu Depression in the East China Sea Shelf Basin. Clarifying the source suppliers and restoring source-to-sink transport routes are of great significance to the future petroleum and gas undertakings. Previous researchers were largely confined by either limitation of geological records, highly dependence on a singular method or low-precision dating techniques. Our study integrated heavy mineral assemblages, geochemica...  相似文献   
12.
The East China Sea Shelf Basin generated a series of back-arc basins with thick successions of marine- and terrestrial-facies sediments during Cenozoic. It is enriched with abundant oil and gas resources and is of great significance to the petroleum exploration undertakings. Therein, the Lishui Sag formed fan delta, fluvial delta and littoral-to-neritic facies sediments during Paleocene–Eocene, and the research on its sedimentary environment and sediment source was controversial. This study analyzed the paleontological combination characteristics, and conducted a source-to-sink comparative analysis to restore the sedimentary environment and provenance evolution of the Lishui Sag during Paleocene–Eocene based on the integration of detrital zircon U-Pb age spectra patterns with paleontological assemblages. The results indicated that Lishui Sag was dominated by littoral and neritic-facies environment during time corroborated by large abundance of foraminifera, calcareous nannofossils and dinoflagellates. Chronological analysis of detrital zircon U-Pb revealed that there were significant differences in sediment sources between the east and west area of the Lishui Sag. The western area was featured by deeper water depths in the Paleocene–Eocene, and the sediment was characterized by a single Yanshanian peak of zircon U-Pb age spectra, and mainly influenced from Yanshanian magmatic rocks of South China Coast and the surrounding paleo-uplifts. However, its eastern area partly showed Indosinian populations. In particular, the upper Eocene Wenzhou sediments were featured by increasingly plentiful Precambrian zircons in addition to the large Indosinian-Yanshanian peaks, indicating a possible impact from the Yushan Low Uplift to the east. Therefore, it is likely that the eastern Lishui Sag generated large river systems as well as deltas during time. Due to the Yuquan Movement, the Lishui Sag experienced uplifting and exhumation in the late stage of the late Eocene and was not deposited with sediments until Miocene. Featured by transitional-facies depositions of Paleocene–Eocene, the Lishui Sag thus beared significant potential for source rock and oil-gas reservoir accumulation.  相似文献   
13.
There are many large-scale Cenozoic sedimentary basins with plentiful river deltas, deep-water fans and carbonate platforms in the southern South China Sea. The Crocker Fan was deposited as a typical submarine fan during the late Eocene–early Miocene, and stretches extensively across the entire Sarawak–Sabah of the northern Borneo area. However, systematic analyses are still lacking regarding its sediment composition and potential source suppliers. No consensus has been reached yet on the provenance evolution and sedimentary infilling processes, which seriously impeded the oil-and-gas exploration undertakings. By combining with sedimentary-facies identification, heavy mineral assemblages, elemental geochemistry and detrital zircon U-Pb dating, this paper aims to generalize an integrated analysis on the potential provenance terranes and restore source-to-sink pathways of the Crocker Fan. In general, the Crocker Fan was initially formed over the Cretaceous–lower/middle Eocene Rajang Group by an angular Rajang unconformity. The continual southward subduction of the proto-South China Sea resulted in magmatic activities and subsequent regional deformation and thrusting along the Lupar Line in the northern Borneo. The lowermost Crocker sequence is featured by a thick conglomerate layer sourced from in-situ or adjacent paleo-uplifts. From the late Eocene to the early Miocene, the Crocker Fan was constantly delivered with voluminous detritus from the Malay Peninsula of the western Sundaland. The Zengmu Basin was widely deposited with delta plain and neritic facies sediments, while the Brunei-Sabah Basin, to the farther east, was ubiquitously characterized by turbiditic sequences. The Crocker Fan successions are overall thick layers of modest-grained sandstones, which formed high-quality reservoirs in the southern South China Sea region.  相似文献   
14.
Water quality in Singapore's coastal area was evaluated with microbial indicators, pathogenic vibrios, chemical tracers and physico-chemical parameters. Sampling sites were grouped into two clusters (coastal sites at (i) northern and (ii) southern part of Singapore). The coastal sites located at northern part of Singapore along the Johor Straits exhibited greater pollution. Principal component analysis revealed that sampling sites at Johor Straits have greater loading on carbamazepine, while turbidity poses greater influence on sampling sites at Singapore Straits. Detection of pathogenic vibrios was also more prominent at Johor Straits than the Singapore Straits. This study examined the spatial variations in Singapore's coastal water quality and provided the baseline information for health risk assessment and future pollution management.  相似文献   
15.
Gahyun Goh  Yign Noh 《Ocean Dynamics》2013,63(9-10):1083-1092
Large eddy simulation (LES) reveals that the Coriolis force plays an important role in seasonal thermocline formation. In the high-latitude ocean, a seasonal thermocline is formed at a certain depth, across which the downward transports of heat and momentum are prohibited. On the other hand, in the equatorial ocean, heat and momentum continue to propagate downward to the deeper ocean without forming a well-defined thermocline. Mechanism to clarify the latitudinal difference is suggested. The depth of a seasonal thermocline h is scaled in terms of both the Ekman length scale λ and the Monin–Obukhov length scale L, as h ??? 0.5()1/2, which is in contrast to the earlier suggestion as h?∝?L.  相似文献   
16.
Zhang  Runhong  Goh  Anthony Teck Chee  Li  Yongqin  Liu  Hanlong  Wang  Lin  Chen  Zhixiong  Zhang  Wengang 《Acta Geotechnica》2022,17(12):5789-5800
Acta Geotechnica - The basal heave stability of the excavation and support system is a major concern to geotechnical design engineers, particularly in soft clay deposits. Conventional methods for...  相似文献   
17.
18.
19.
20.
Hydrological Studies and Water Resource Concerns in Southeast Asia   总被引:1,自引:0,他引:1  
Water supply shortage has become a pressing issue in Southeast Asia in recent years. While on the one hand water demand is escalating with rapid economic development, urbanisation and related population concentrations, on the other, surface water supply sources are increasingly being threatened by the resultant land use changes. Therefore, any understanding of the region's water supply concerns necessarily takes into account the hydrological processes and changes consequent to human interference of the natural environment. Changes to the environment that curtail the quantity of water supply and affect its quality will in turn have implications for water resource issues in megacities and other urban areas. Equally critical to the supply of water are water resource and management issues, in particular, the adequate provision of safe water for human consumption, regarded as not only meeting a basic need but also a human right. This paper provides an overview of hydrological processes and water resource concerns and suggests the scope for further investigation, particularly by geographers.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号