全文获取类型
| 收费全文 | 81篇 |
| 免费 | 1篇 |
专业分类
| 测绘学 | 23篇 |
| 大气科学 | 4篇 |
| 地球物理 | 9篇 |
| 地质学 | 13篇 |
| 海洋学 | 2篇 |
| 天文学 | 8篇 |
| 自然地理 | 23篇 |
出版年
| 2020年 | 1篇 |
| 2019年 | 2篇 |
| 2017年 | 1篇 |
| 2015年 | 2篇 |
| 2014年 | 2篇 |
| 2012年 | 2篇 |
| 2011年 | 2篇 |
| 2010年 | 1篇 |
| 2008年 | 4篇 |
| 2007年 | 1篇 |
| 2005年 | 1篇 |
| 2004年 | 7篇 |
| 2003年 | 3篇 |
| 2001年 | 1篇 |
| 2000年 | 3篇 |
| 1998年 | 2篇 |
| 1997年 | 1篇 |
| 1995年 | 1篇 |
| 1994年 | 2篇 |
| 1993年 | 7篇 |
| 1992年 | 3篇 |
| 1991年 | 5篇 |
| 1990年 | 2篇 |
| 1989年 | 2篇 |
| 1987年 | 3篇 |
| 1985年 | 3篇 |
| 1984年 | 1篇 |
| 1983年 | 4篇 |
| 1982年 | 3篇 |
| 1981年 | 1篇 |
| 1979年 | 3篇 |
| 1977年 | 4篇 |
| 1975年 | 1篇 |
| 1974年 | 1篇 |
排序方式： 共有82条查询结果，搜索用时 15 毫秒
61.
62.
In order to improve understanding of the stratigraphy of the Lake Turkana Basin, one of the important sites in the evolution of early man, this study evaluates the usefulness of organic biological marker compounds, n-alkanes and fatty acids, for correlation of isolated sedimentary strata.Eighty-five paleosol samples were collected from well-defined sedimentary horizons in two regions (Area 103 and Area 130) of the Koobi Fora area of Lake Turkana. Results indicate that most of the organic matter present was derived from terrestrial plant waxes. In sediments where extensive diagenesis has occurred, microbial input of organic matter may have been substantial. Algae were either not an important source of organic matter, or their marker compounds have been removed or altered by degradative processes.The fate of the original paleosol organic matter has been governed to some extent by weathering processes, especially in Area 130. Weathering decreased the amount of extractable lipids, particularly fatty acids and the low molecular weight alkanes (C17C20); produced or retained relatively large amounts of alkanes greater than C21 within a unimodal distribution; and lowered CPI values. Consequently, stratigraphic correlation by unique alkane and fatty acid distributions has been confined to short distances (many meters).Both n-alkanes and fatty acids have been retained better by association with clay minerals than by sand matrices. The alkane distribution of sandstones differs from that of clay organics in having a narrower carbon chain length distribution and lower CPI values. In Area 103, where weathering was less severe, compositional variations with stratigraphic position indicate that lipid material has been retained within each of the facies examined. 相似文献
63.
The authors describe the method adopted to prepare a photogrammetric record drawing of both the interior and the exterior stonework tracery of the west window of York Minster. 相似文献
64.
R. W. A. Dallas 《The Photogrammetric Record》1991,13(77):834-835
65.
66.
67.
68.
In this ‘Thinking Space’ essay we revisit Maurie Daly’s 1982 book Sydney Boom, Sydney Bust, fuelled by concern for how Australian cities are being transformed by financialised real estate. Daly's insights remain highly relevant to Sydney and other cities around Australia and the world today. Poorly planned densification, inflated property markets, land speculation, and housing poverty are all outcomes of the (global) capitalist intersection of finance and land in Australia. The overwriting of Aboriginal country with colonial-capitalist systems of land ownership set in train a process of land and housing booms, bubbles and busts that are better understood by their circular continuity rather than as a set of ephemeral ruptures. It is the property and finance system itself, rather than any ruptures to it, that reproduces unequal and alienating social relations. Researchers investigating property speculation, global capital, urban planning and financialisation, we argue, ought to revisit this key text to inform their contemporary analyses. Moreover, those wielding power over Australian urban affairs would do well to read it too, lest its lessons be ignored for another generation. 相似文献
69.
Following the disastrous fire in the State Apartments at Windsor Castle in 1992, a programme of photogrammetric surveying followed by archaeological recording was carried out by English Heritage. This paper details the background to this work, the provision of the photogrammetric surveys and the use and analysis of the data by the archaeology team. 相似文献
70.
In order to alleviate the threat of global climate change, coordinated international action is needed. This cooperation should include multilateral agreements and new economic initiatives to help implement measures that will slow the accumulation of carbon dioxide in the Earth's atmosphere due to tropical deforestation and fossil-fuel use. An international market in environmental services can help to safeguard the Earth's climate and foster economic development through a North-South transfer of financial resources.We suggest international carbon-emission offsets (ICEOs) as a means by which international markets, under a policy umbrella such as a multilateral climate-protection treaty, could trade carbon-saving services. Such a market would provide a currency for rewarding actions that reduce global carbon emissions, allowing carbon emitters to seek the least expensive ways to reduce emissions. This currency would transfer cash and/or debt relief from industrialized nations to developing nations, allowing the developing nations to profit from the use of clean energy technologies and the protection, rather than depletion, of tropical forests. 相似文献