全文获取类型
收费全文 | 1176篇 |
免费 | 39篇 |
出版年
2022年 | 6篇 |
2020年 | 10篇 |
2019年 | 26篇 |
2018年 | 29篇 |
2017年 | 38篇 |
2016年 | 34篇 |
2015年 | 26篇 |
2014年 | 30篇 |
2013年 | 422篇 |
2012年 | 20篇 |
2011年 | 30篇 |
2010年 | 31篇 |
2009年 | 15篇 |
2008年 | 10篇 |
2007年 | 25篇 |
2006年 | 11篇 |
2005年 | 17篇 |
2004年 | 18篇 |
2003年 | 18篇 |
2002年 | 13篇 |
2001年 | 15篇 |
2000年 | 19篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1996年 | 9篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 6篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1983年 | 10篇 |
1982年 | 16篇 |
1981年 | 9篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 19篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1974年 | 14篇 |
1973年 | 13篇 |
1972年 | 15篇 |
1971年 | 6篇 |
1970年 | 5篇 |
排序方式: 共有1215条查询结果,搜索用时 31 毫秒
41.
42.
43.
44.
William A. Koelsch 《Journal of Historical Geography》1982,8(4):362-372
This paper examines a nineteenth-century geographic activity, the recreational exploration of the wilderness areas of northern New England and nearby environments by Harvard students. Conventions of literary expression and social behaviour spurred and shaped such activity, but undergirding these temporally-specific patterns were more universal characteristics of late-adolescent behaviour. Biological, anthropological and what may be called geographical imperatives led students to explore the limits of their regional environment and incorporate the values of the wilderness experience into their own maturational processes. The early journeys into the eastern wilderness of the geographical historian Francis Parkman are set in the context of these more universal institutional and behavioural patterns. 相似文献
45.
William R. Farrand 《Journal of archaeological science》1979,6(4):369-392
Analysis of sediments from the sites of et-Tabun, Jebel Qafza, and Sefunim in Israel, of Ksar 'Aqil in Lebanon, and of Yabrud Rockshelter I and Jerf 'Ajla in Syria leads to a reconstruction of the environments of deposition, periods of weathering and erosion, and relations to changing sea level during the times of occupation of these sites by prehistoric man. The overlapping sequences span the interval from part or all of the last interglaciation through the time of the last glaciation into historic time. Aeolians and from the last interglacial littoral zone and aeolian silt from more distant deserts dominate the site sediments until the early part of the last glaciation (especially at Tabun), whereas colluvial slope deposits, alluvium (Ksar 'Aqil), and angular rockfall debris are characteristic of the mid-last glaciation sediments in most sites, commonly with an admixture of reworked terra rossa soil sediment. These latter sediments seem to reflect a period or periods of greater available moisture or surface run-off. Prominent unconformities mark many sites at times coincident with the final middle palaeolithic (mousterian) occupations or in the interval between middle palaeolithic and upper palaeolithic occupations. It is not clear, in the absence of firm radiometric dates, whether these hiatuses should be correlated from site-to-site or whether they are site-specific. Freeze/thaw phenomena appear not to have played a significant role, if any at all, in the origin of sediments in coastal Levantine sites, although the middle palaeolithic of the Syrian Desert (Yabrud, Jerf 'Ajla) is contained in typical cryoclastic rubble. Finally, the reconstructed sedimentary environments are compared with the still-too-sparse palynological record for the Near East. Parallels of more humid and less humid climatic intervals throughout the past 60,000 to 70,000 years in both of these records reinforce the growing impression of a regionally fluctuating climate in the eastern Mediterranean region during the time of the last glaciation. 相似文献
46.
47.
48.
49.
50.