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   42220篇
  免费   1651篇
  2020年   546篇
  2019年   839篇
  2018年   967篇
  2017年   1164篇
  2016年   1248篇
  2015年   940篇
  2014年   912篇
  2013年   14156篇
  2012年   1068篇
  2011年   1088篇
  2010年   1092篇
  2009年   1087篇
  2008年   1023篇
  2007年   929篇
  2006年   840篇
  2005年   590篇
  2004年   578篇
  2003年   536篇
  2002年   519篇
  2001年   527篇
  2000年   467篇
  1999年   532篇
  1998年   471篇
  1997年   430篇
  1996年   409篇
  1995年   414篇
  1994年   365篇
  1993年   416篇
  1992年   396篇
  1991年   298篇
  1990年   294篇
  1989年   313篇
  1988年   314篇
  1987年   331篇
  1986年   319篇
  1985年   424篇
  1984年   455篇
  1983年   472篇
  1982年   401篇
  1981年   394篇
  1980年   435篇
  1979年   431篇
  1978年   412篇
  1977年   427篇
  1976年   387篇
  1975年   390篇
  1974年   292篇
  1973年   274篇
  1972年   248篇
  1970年   221篇
排序方式: 共有10000条查询结果,搜索用时 272 毫秒
891.
Structural adjustment, democratization and rising ethnic tensions characterize the current situation in much of Africa today. This article examines how these tendencies interact causally. It begins by describing Africa's growing debt (combined with defence) burden, the nature of the structural adjustment programme (SAP), particularly its pressures and contradictions, and the increasingly authoritarian responses generated by these. After illustrating the linkage between SAP and rising ethnic tensions, it is suggested that the issue of the distribution of power, wealth and ethnicity, especially under conditions of increasing scarcity, needs to be reconsidered. There are a number of reasons why ethnic and regional tensions are exacerbated by debts, economic crisis and adjustment in Africa; a core argument of this article is that the current ethnic tensions, like the ongoing democratic struggles, are arising as part of the general resistance against both SAP, because of its pauperizing impact, and against the state, which is seen as increasingly coercive and as negligent of its basic welfare responsibilities towards its citizens. The article ends by considering the implications of the coincidence of these two foci of resistance not only for the democratization project, but also for the survival of the state in Africa.  相似文献   
892.
Reviews     
  相似文献   
893.
894.
895.
896.
897.
898.
The Pacific Coast of North America was occupied by many distinctive groups of coastal hunter-gatherers at the times of early contacts with Europeans. Despite significant cultural diversity, Pacific Coast peoples shared lifeways oriented toward generally similar marine, nearshore, littoral, and estuarine habitats. In this paper, we examine some major issues that guide much of the archaeology done along the Pacific Coast, then discuss some of the theoretical and methodological problems that limit the efficacy of archaeological reconstructions. Most archaeological research conducted on North America's Pacific Coast has been oriented toward the search for the origins and development of a variety of cultural patterns. A comparative review of California and Northwest Coast sequences provides interesting parallels and discrepancies in the approaches taken in studying some of the major issues in Pacific Coast prehistory.  相似文献   
899.
The fossil record suggests that modern human morphology evolved in Africa between 150,000 and 50,000 years ago, when the sole inhabitants of Eurasia were the Neanderthals and other equally nonmodern people. However, the earliest modern or near-modern Africans were behaviorally (archaeologically) indistinguishable from their nonmodern, Eurasian contemporaries, and it was only around 50,000-40,000 years ago that a major behavioral difference developed. Archaeological indications of this difference include the oldest indisputable ornaments (or art broadly understood); the oldest evidence for routine use of bone, ivory, and shell to produce formal (standardized) artifacts; greatly accelerated variation in stone artifact assemblages through time and space; and hunting-gathering innovations that promoted significantly larger populations. As a complex, the novel traits imply fully modern cognitive and communicative abilities, or more succinctly, the fully modern capacity for Culture. The competitive advantage of this capacity is obvious, and preliminary dates suggest that it appeared in Africa about 50,000 years ago and then successively in western Asia, eastern Europe, and western Europe, in keeping with an African origin. Arguably, the development of modern behavior depended on a neural change broadly like those that accompanied yet earlier archaeologically detectable behavioral advances. This explanation is problematic, however, because the putative change was in brain organization, not size, and fossil skulls provide little or no secure evidence for brain structure. Other potential objections to a neural advance in Africa 50,000-40,000 years ago or to the wider Out-of-Africa hypothesis, include archaeological evidence (1) that some Neanderthals were actually capable of fully modern behavior and (2) that some Africans were behaviorally modern more than 90,000 years ago.  相似文献   
900.
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