全文获取类型
收费全文 | 8593篇 |
免费 | 308篇 |
专业分类
8901篇 |
出版年
2020年 | 115篇 |
2019年 | 161篇 |
2018年 | 171篇 |
2017年 | 211篇 |
2016年 | 287篇 |
2015年 | 185篇 |
2014年 | 169篇 |
2013年 | 2186篇 |
2012年 | 212篇 |
2011年 | 256篇 |
2010年 | 235篇 |
2009年 | 207篇 |
2008年 | 198篇 |
2007年 | 170篇 |
2006年 | 161篇 |
2005年 | 111篇 |
2004年 | 114篇 |
2003年 | 103篇 |
2002年 | 115篇 |
2001年 | 126篇 |
2000年 | 136篇 |
1999年 | 172篇 |
1998年 | 114篇 |
1997年 | 75篇 |
1996年 | 87篇 |
1995年 | 94篇 |
1994年 | 91篇 |
1993年 | 93篇 |
1992年 | 96篇 |
1991年 | 75篇 |
1990年 | 75篇 |
1989年 | 78篇 |
1988年 | 85篇 |
1987年 | 92篇 |
1986年 | 86篇 |
1985年 | 122篇 |
1984年 | 121篇 |
1983年 | 129篇 |
1982年 | 99篇 |
1981年 | 104篇 |
1980年 | 107篇 |
1979年 | 102篇 |
1978年 | 94篇 |
1977年 | 108篇 |
1976年 | 86篇 |
1975年 | 95篇 |
1974年 | 83篇 |
1973年 | 79篇 |
1972年 | 62篇 |
1971年 | 65篇 |
排序方式: 共有8901条查询结果,搜索用时 46 毫秒
991.
The BUNTEP programme has established itself as a successful innovator and purveyor of higher education to a hitherto neglected segment of the Canadian mosaic the isolated lndian reserves of northern Manitoba. BUNTEP comes at a time, however, when the reserves isolation from the outside world is breaking down. Combined with the stresses imposed by the post-war nuclear settlement policy of the government and the stresses of the population explosion, the formerly isolated bands are confronting challenges they are ill-equipped to meet. Television (which reached some reserves as recently as December 1977). the telephone, airplanes, motorboats, snowmobiles, and all the convenience goods sold at the local Hudson's Bay Company stores are steadily undermining whatever traditional culture is left. It is hoped that BUNTEP, and the successful graduates of BUNTEP, may provide these isolated communities with a means of coming to terms with the increasingly intrusive greater Canadian society. 相似文献
992.
993.
994.
S.?WurzEmail author P.?Van?Peer N.?le?Roux S.?Gardner H.?J.?Deacon 《African Archaeological Review》2005,22(1):1-24
The technology of the end products i.e. blades and points in Late Pleistocene stone artefact assemblages from Klasies River, South Africa, and the Nile Valley, Egypt, are compared. The comparison includes univariate and multivariate analysis of metrical attributes enhanced by graphical biplot displays. The end products in these assemblages are either dominantly points or blades and this is related to the core reduction strategy adopted. The MSA 11 from Klasies River and the Nubian Complex industry from the Nile Valley are point industries made in the Levallois tradition, while the MSA 1 from Klasies River and the Taramsan from the Nile Valley may be non-Levallois or adapted Levallois blade industries. Dating of the assemblages shows the changes between dominant core reduction strategies are sequential and time restricted in both South and North Africa. It is concluded that variability of the same kind occurs in Middle Stone Age and Middle Palaeolithic assemblages south and north of the Sahara in the early Late Pleistocene.Dans cet article, les technologies des produits recherchés, des lames et des pointes, pour certains ensembles lithiques de Klasies River, Afrique du Sud et la Vallée du Nil, Egypte, sont comparées. Cette comparaison implique des analyses univariées et multivariées de variables métriques biplot. Les produits recherchés sont bien des pointes que des lames, selon les stratégies dexploitation adoptées. Le MSA II de Klasies River et le Complexe nubien de la Vallée du Nil sont des industries à pointes issues de la tradition Levallois. Par contre, le MSA I de Klasies River et le Taramsien de la Vallée du Nil évoquent une technologie de production non-Levallois ou Levallois modifiée. Les éléments de datation disponibles indiquent que les changements dans la prépondérance des stratégies dexploitation senchaînent dans une séquence chronologique bien identifiable, aussibien dans lAfrique du Sud que lAfrique du Nord. On arrive à la conclusion quune variabilité du même caractère est attestée dans les ensembles du Middle Stone Age et du Paléolithique moyen au sud et au nord du Sahara, pendant le Pléistocène supérieur ancien. 相似文献
995.
996.
997.
998.
999.
This paper details the discovery of two perinatal individuals interred simultaneously at the archaeological site of Olèrdola, Barcelona, Spain. Information from the excavation and from the subsequent anthropological study of the recovered skeletal and dental remains suggests that these individuals (OL–2000–8245 and OL–2000–8246) are the first documented case of twins in Iberian period. The possibility of a simultaneous perinatal twins burial at Olèrdola raises new questions concerning about the frequency of twins in prehistory and protohistory. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
1000.
J. David Wood 《The Canadian geographer》2006,50(1):38-55
As the twentieth century opened, there were rumours that the cheap land underpinning the dramatic spread of settlement in the previous century might be running out. There were strong motivations, generated particularly by the large body of land seekers with a passion for farming, to hold off the demise of the famous agricultural frontier. Also wedded to the continuation of a frontier were politicians and civil servants across the country. Whether it was a subconscious expectation that the frontier would simply continue or a fear that its disappearance would lead to unpredictable social disturbance, politicians encouraged expansion beyond what was known to be good farmland. The major source of new land, from c . 1910, was the boreal forest. There was a steady accumulation of information about the North that was readily available to government officials but only indirectly to ordinary land seekers. Although the news about farming conditions in the boreal margin was unpromising except for a few pockets, independent and assisted farm settlements continued into the 1930s. The typical two-thirds of farm failure within one generation in most of the new boreal settlements caused a great deal of settler grief and forced reluctant officials to respond to the negative scientific evidence and to reassess frontier nostalgia. The Second World War provided both a denouement of the northern farm settlement and a reason for many people to depart the 'last frontier'. 相似文献