首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8587篇
  免费   306篇
  8893篇
  2020年   115篇
  2019年   161篇
  2018年   171篇
  2017年   211篇
  2016年   287篇
  2015年   182篇
  2014年   168篇
  2013年   2184篇
  2012年   211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   114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8893条查询结果,搜索用时 15 毫秒
991.
992.
993.
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   
994.
995.
996.
997.
998.
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   
999.
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   
1000.
The approaches of comparative studies and profile measurements, often used in order to detect post‐depositional alterations of ceramics, have been applied simultaneously to two sets of Roman pottery, both of which include altered individuals. As analytical techniques, Neutron Activation Analysis and X‐Ray Diffraction have been used. Both approaches lead to substantially different results. This shows that they detect different levels of alteration and should complement each other rather than being used exclusively. For the special process of a glassy phase decomposition followed by a crystallization of the Na‐zeolite analcime, the results suggest that it changes high‐fired calcareous pottery rapidly, and so fundamentally that the results of various archaeometric techniques can be severely disturbed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号