全文获取类型
| 收费全文 | 120篇 |
| 免费 | 1篇 |
| 国内免费 | 1篇 |
专业分类
| 测绘学 | 6篇 |
| 大气科学 | 10篇 |
| 地球物理 | 33篇 |
| 地质学 | 36篇 |
| 海洋学 | 20篇 |
| 天文学 | 6篇 |
| 自然地理 | 11篇 |
出版年
| 2023年 | 2篇 |
| 2021年 | 1篇 |
| 2020年 | 2篇 |
| 2019年 | 4篇 |
| 2018年 | 5篇 |
| 2017年 | 1篇 |
| 2016年 | 6篇 |
| 2015年 | 4篇 |
| 2014年 | 4篇 |
| 2013年 | 13篇 |
| 2012年 | 4篇 |
| 2011年 | 5篇 |
| 2010年 | 3篇 |
| 2009年 | 6篇 |
| 2008年 | 2篇 |
| 2007年 | 8篇 |
| 2006年 | 7篇 |
| 2005年 | 3篇 |
| 2004年 | 2篇 |
| 2003年 | 4篇 |
| 2002年 | 7篇 |
| 2001年 | 6篇 |
| 2000年 | 3篇 |
| 1999年 | 4篇 |
| 1998年 | 1篇 |
| 1997年 | 1篇 |
| 1996年 | 2篇 |
| 1995年 | 1篇 |
| 1991年 | 3篇 |
| 1990年 | 2篇 |
| 1987年 | 1篇 |
| 1982年 | 1篇 |
| 1981年 | 3篇 |
| 1976年 | 1篇 |
排序方式： 共有122条查询结果，搜索用时 31 毫秒
101.
102.
103.
104.
Thermal modeling of the Southern Alps,New Zealand 总被引：1，自引：0，他引：1
Finite-element modeling of the thermal regime across the Southern Alps of New Zealand has been carried out along two profiles situated near the Franz Josef and Haast valleys. The modeling involves viscous deformation beneath the Southern Alps, including both uplift and erosion, and crustal/lithospheric thickening, as a result of crustal shortening extending to 20 mm/y of a 25-km thick crust. Published uplift rates and crustal thickness variations along the two profiles are used to constrain the modeled advection of crustal material, and results are compared with the recent heat flow determinations, 190±50 mW/m2 in the Franz Josef valley and 90±25 mW/m2 in the Haast valley. Comparisons of the model with published K–Ar and fission track ages, show that the observed heat flow in the Franz Josef valley is consistent with observed zircon fission track ages of around 1 Ma, if the present-day uplift rate is close to 10 mm/y. Major thermal differences between the Franz Josef and Haast profiles appear to be due to different uplift and erosion rates. There is weak evidence that frictional heating close to the Alpine fault zone is not significant. The modeling provides explanations for the distribution of seismicity beneath the Southern Alps, and predicts a low surface heat flow over the eastern foothills due to the dominant thermal effect of crustal thickening beneath this region. Predicted temperatures at mid-crustal depth beneath the zone of maximum uplift rate are 50–100°C cooler than those indicated in previously published models, which implies that thermal weakening of the crust may not be the main factor causing the aseismicity of the central Southern Alps. The results of the modeling demonstrate that the different types of reset age data in the region within 25 km of the Alpine fault are critical for constraining models of the deformation and the thermal regime beneath the Southern Alps. 相似文献
105.
Rick A. Hagen Nancy A. Baker David F. Naar R. N. Hey 《Marine Geophysical Researches》1990,12(4):297-315
SeaMARC II side-scan sonar data reveal that a large area of seafloor north and west of Easter Island has been disrupted by
recent submarine volcanism. A large volcanic area begins approximately 60 km WNW of the island and extends for over 130 km
to the west. The volcanic field is characterized by high backscatter intensity in the side-scan sonar records and is elevated
400–1000 m above the N-S seafloor fabric that surrounds it. This field, the Abu Volcanic Field, covers at least 2500 km2 and appears to consist of recent lava flows and small volcanoes. Backscatter intensity of the Abu Volcanic Field is similar
to that of the adjacent ridge flank which is less than 0.4 Ma, suggesting a similar age for its formation.
Two additional areas of high backscatter immediately north of Easter Island cover a combined area of over 300 km2. The sidescan sonar records show that these features are clearly of volcanic origin and are not debris flows from the nearby
island. The flows are nearly 300 m thick and are morphologically similar to subaerial pahoehoe lava shields. Their high backscatter
indicates that they are also the products of relatively recent submarine volcanic activity.
The presence of these large areas of recent volcanism in the vicinity of Easter Island has important implications for the
various models that have been proposed to explain the origin of the Easter Seamount Chain. In addition, the similar ages of
Easter Island and the Easter Microplate suggest that the presence of a hotspot near or beneath this fast-spreading portion
of the East Pacific Rise about 4.5 m.y. ago may have initiated the large-scale rift propagation that created the microplate. 相似文献
106.
The Mersey estuary is the most contaminated estuary in British waters. Detailed studies are underway on the pathology of flounder (Platichthys flesus) from the Mersey and on flounder from the nearby, but less contaminated, Dee estuary. Flounder breed offshore but spend a lot of time in the estuaries, penetrating into freshwater. These flatfish are in close contact with sediments and will be exposed to exenobiotic stored in the sediments. Plaice (Pleuronectes platessa) are flatfish which enter the Mersey with the tidal flow but spend less time in the estuary than flounder and are less likely to show evidence of pollutant exposure. Over 20 plaice were collected from the Mersey. Samples of the liver, kidney and gonad were fixed in 10% formal saline, processed into paraffin wax and 5 microm sections cut and stained with haematoxylin and eosin. Liver changes consisted of variable amounts of glycogen/lipid storage product, minor perivenular and perivascular fibrosis, and helminth parasitisation. No tumours or foci of cellular alteration, necrosis and inflammation were seen. In the gonad only changes consistent with normal gonadal cycling was seen. These studies provide evidence that plaice show little or no evidence of toxic pathological damage resulting from their stay in the estuary. 相似文献
107.
David Petruska Jeff Geyer Rick Macon Michael Craig Alex Ran Neil Schulz 《Ocean Engineering》2005,32(7):767-782
The Mad dog project will use a polyester mooring system on the drilling and production truss spar. This will be the first use of a permanent polyester mooring system on a Floating Production System (FPS) outside of Brazil and the first time polyester has been used on a spar. As such, there were many challenges, which include:
- • Regulatory approval.
- • Designing a mooring system which is dominated by current loadings.
- • Largest polyester rope break load ever required.
- • Rope design qualification and testing.
- • Quality control and assurance.
- • Inspection, Maintenance, Repair and Retirement (IMRR) of such a mooring system.
108.
109.
Jun Wang Daniel G. Brown Rick L. Riolo Scott E. Page Arun Agrawal 《Global Environmental Change》2013,23(5):1266-1276
There has been a decrease in grazing mobility in the Mongolian grasslands over the past decades. Sedentary grazing with substantial external inputs has increased the cost of livestock production. As a result, the livelihoods of herders have become more vulnerable to climate variability and change. Sedentary grazing is the formal institutional arrangement in Inner Mongolia, China. However, this may not be an efficient institutional arrangement for climate change adaptation. Self-organized local institutions for climate change adaptation have emerged and are under development in the study area. In this study, we did exploratory analyses of multiple local institutions for climate change adaptation in the Mongolian grasslands, using an agent-based modeling approach. Empirical studies from literature and our field work show that sedentary grazing, pasture rental markets, and reciprocal pasture-use groups are three popular institutional arrangements in the study area. First, we modeled the social–ecological performance (i.e., livelihood benefits to herders and grassland quality) of these institutions and their combinations under different climate conditions. Second, we did exploratory analyses of multiple social mechanisms for facilitating and maintaining cooperative use of pastures among herders. The modeling results show that in certain value-ranges of some model parameters with assumed values, reciprocal pasture-use groups had better performance than pasture rental markets; and the comparative advantage of cooperative use of pastures over sedentary grazing without cooperation becomes more evident with the increase in drought probability. Agent diversity and social norms were effective for facilitating the development of reciprocal pasture-use groups. Kin selection and punishments on free-riders were useful for maintaining cooperation among herders. 相似文献
110.