全文获取类型
收费全文 | 564篇 |
免费 | 10篇 |
专业分类
测绘学 | 14篇 |
大气科学 | 109篇 |
地球物理 | 114篇 |
地质学 | 220篇 |
海洋学 | 38篇 |
天文学 | 40篇 |
自然地理 | 39篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 19篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 27篇 |
2010年 | 37篇 |
2009年 | 21篇 |
2008年 | 18篇 |
2007年 | 24篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 26篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1993年 | 4篇 |
1992年 | 12篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1973年 | 6篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1954年 | 3篇 |
排序方式: 共有574条查询结果,搜索用时 176 毫秒
31.
R. Müller J.-U. Grooß D. S. McKenna P. J. Crutzen C. Brühl J. M. Russell III L. L. Gordley J. P. Burrows A. F. Tuck 《Annales Geophysicae》1998,17(1):101-114
Severe chemical ozone loss has been detected in the Arctic in the winter and spring of 1995–96 by a variety of methods. Extreme reductions in column ozone due to halogen catalysed chemistry were derived from measurements of the Halogen Occultation Experiment (HALOE) on board the Upper Atmosphere Research Satellite in the Arctic vortex. Here, we discuss further aspects of the HALOE observations in the Arctic over this period. Potential problems, both in the data themselves and in the methodology of the data analysis are considered and the reason for the differences between the Arctic ozone losses deduced from HALOE data version 17 and 18 is analysed. Moreover, it is shown that HALOE measurements in the Arctic in winter and spring 1995–96 compare well with observations by other ground-based and satellite instruments. 相似文献
32.
Cluster correspondence analysis examines the spatial autocorrelation of multi-location events at the local scale. This paper
argues that patterns of cluster correspondence are highly sensitive to the definition of operational neighborhoods that form
the spatial units of analysis. A subset of multi-location events is examined for cluster correspondence if they are associated
with the same operational neighborhood. This paper discusses the construction of operational neighborhoods for cluster correspondence
analysis based on the spatial properties of the underlying zoning system and the scales at which the zones are aggregated
into neighborhoods. Impacts of this construction on the degree of cluster correspondence are also analyzed. Empirical analyses
of cluster correspondence between paired vehicle theft and recovery locations are conducted on different zoning methods and
across a series of geographic scales and the dynamics of cluster correspondence patterns are discussed.
相似文献
33.
Until the mid-1980s, transport policy was considered by many as one of the least successful domains of the European integration project. However, from the early 1990s onwards, there are clear signs of a single European transport policy, along with the accompanying implementation of infrastructure projects. What is the explanation for such a change in pace? This paper aims to offer insight in these processes by looking at the mechanisms which form and transform this policy domain. To understand the state of a policy domain and its dynamics over time an institutional approach is taken. Two concepts in political science, ‘policy arrangements’ and ‘supranational governance’ are combined and used as a framework to analyse the European transport policy domain. This analysis describes the development of several elements: organisations, rules, the transnational society, power, resources, and the central transport discourse. It demonstrates that all of these elements have developed from an intergovernmental setting towards a more supranational one. This development was slow in the first decennia when European transport policy was rather passive, but it picked up speed in the 1980s and 1990s. In the pivotal year of 1985, pressure from the transnational society resulted in a rapid change of the rules, the resources and the discourse. 相似文献
34.
Wilckens W. Brückner Wasmund Leuchs Bubnoff 《International Journal of Earth Sciences》1936,27(4):393-397
Ohne Zusammenfassung 相似文献
35.
Werner Brückner 《International Journal of Earth Sciences》1951,39(1):196-212
Ohne Zusammenfassung 相似文献
36.
Nicolas Mazzella Josiane Molinet Agung Dhamar Syakti Jean-Claude Bertrand Pierre Doumenq 《Marine Chemistry》2007,103(3-4):304-317
This in situ study reports on the relevance of intact phospholipids as new biomarkers and highlights the limits of the classical fatty acid analysis after the hydrolysis of the polar lipid fraction. The analysis of polar lipid fractions revealed significant contributions of marine macrophytes with either non-phospholipid compounds (sulfoquinovosyl diacylglycerol) or with both non-bacterial phospholipid classes (phosphatidylcholine) and non-bacterial phospholipid molecular species (some molecular species of phosphatidylglycerol). The analysis of intact phospholipids showed also the predominance of gram-negative bacteria in sediments whereas the analysis of fatty acids alone cannot confirm such information. Lastly, as regard to the effects of petroleum hydrocarbons on the sedimentary bacterial communities, we observed a higher degree of saturation of the fatty acyl chains of the phospholipids extracted from sediment exposed to a massive and chronic crude oil contamination. Such a result was interpreted as an adaptive response resulting in higher membrane rigidity of the bacterial communities. 相似文献
37.
Since the beginning of formation of Proto-Taiwan, the subducting Philippine (PH) Sea plate has moved continuously through
time in the N307° direction with respect to Eurasia (EU), tearing the EU plate. The subducting EU plate includes a continental
part in the north and an oceanic part in the south. The boundary B between these two domains corresponds to the eastern prolongation
of the northeastern South China Sea ocean-continent transition zone. In the Huatung Basin (east of Taiwan), the Taitung Canyon
is N065° oriented and is close and parallel to B. Seismic profiles show that the southern flank of the canyon corresponds
to a fault with a normal component of a few tens of meters in the sediments and possible dextral shearing. Several crustal
earthquakes of magnitude >%6 are located beneath the trend of the Taitung Canyon and focal mechanisms suggest that the motion
is right-lateral. Thus, faulting within the sedimentary sequence beneath the Taitung Canyon is a consequence of underlying
dextral strike-slip crustal motions. As the continental part of the EU slab located north of B has been recently detached,
some subsequent dextral strike-slip motion might be expected within the EU slab, along the ocean-continent transition zone,
which is a potential zone of weakness. We suggest that the dextral strike-slip motion along the ocean-continent boundary of
the EU slab might trigger the observed dextral strike-slip motion within the overlying PH Sea crust and the associated faulting
within the sediments of the Huatung Basin, beneath the Taitung Canyon.
An erratum to this article is available at . 相似文献
38.
Combining indicator trends to assess ongoing changes in exploited fish communities: diagnostic of communities off the coasts of France 总被引:1,自引:1,他引:1
39.
Hans Olav Bråtå 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(5):301-312
The aim of the article is to analyse challenges facing the commercial production of historical beers, which are ‘extinct’ beers. The concept of ‘fictive terroir’ is introduced to emphasize these challenges. The author addresses the following questions: What kind of knowledge is needed to produce historical beers? How can this knowledge be acquired? How can it be used commercially in craft breweries? The studied case is Vossaøl, a craft beer imitation of a beer produced in the early 19th century. The data were obtained from written sources and interviews with local home brewers and brewers at Voss Brewery in Norway. The study revealed the need to reconstruct the terroir in the early 19th century. Additionally, Voss Brewery had to acquire knowledge about how to process and combine the ingredients, which included the traditional yeast (kveik). Involving traditional home brewers was crucial to determine how ingredients could be combined to produce Vossaøl. The author concludes that a synthetic knowledge base was a useful point of departure in this respect. Participation in the traditional culture of brewing proved an important means when working with this knowledge base. The results are interesting in the broader context of the reconstruction of beverages and food. 相似文献
40.