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   5805篇
  免费   147篇
  5952篇
  2020年   47篇
  2019年   92篇
  2018年   380篇
  2017年   300篇
  2016年   338篇
  2015年   97篇
  2014年   88篇
  2013年   1348篇
  2012年   157篇
  2011年   268篇
  2010年   318篇
  2009年   182篇
  2008年   165篇
  2007年   230篇
  2006年   99篇
  2005年   91篇
  2004年   61篇
  2003年   56篇
  2002年   61篇
  2001年   71篇
  2000年   54篇
  1999年   64篇
  1998年   63篇
  1997年   49篇
  1996年   60篇
  1995年   45篇
  1994年   49篇
  1993年   46篇
  1992年   44篇
  1991年   38篇
  1990年   27篇
  1989年   44篇
  1988年   38篇
  1987年   52篇
  1986年   38篇
  1985年   42篇
  1984年   52篇
  1983年   43篇
  1982年   33篇
  1981年   45篇
  1980年   52篇
  1979年   45篇
  1978年   29篇
  1977年   56篇
  1976年   37篇
  1975年   43篇
  1974年   23篇
  1972年   26篇
  1970年   23篇
  1969年   23篇
排序方式: 共有5952条查询结果,搜索用时 15 毫秒
151.
152.
153.
154.
155.
Developers seeking to assemble complementary parcels of land will likely encounter strategic behavior by landowners. Using a property‐level data set from Florida's Department of Transportation covering the period January 2000 to July 2014, I test whether bargaining delays lead to higher final transaction prices. Given the nature of the data, I can compare properties within the same roadway project to estimate the effect of delayed negotiations. My empirical estimates indicate that bargaining delays lead to increased final transaction prices. The magnitude of this effect is approximately 7 percent for the average holdout, however, the effect is nonlinear and diminishes over time.  相似文献   
156.
Archaeologists have debated the degree of complexity at Mississippian period polities with some arguing that they were highly stratified and centralized and others arguing that they were politically decentralized. Faunal analyses from the Cahokia Mounds and Moundville polities have been used to suggest that there were significant differences in the foodways of elite and nonelite peoples and that deer remains were part of redistributive economies. In this article, I discuss the distribution of faunal remains from five archaeological contexts at the Kincaid Mounds site in southern Illinois. In particular, I explore species diversity and the distribution of deer body parts using utility indices and anatomical units and compare these results to Cahokia Mounds and other Mississippian period villages in southern Illinois. The distribution of taxa and deer elements from both the mound- and nonmound-related contexts at Kincaid follows patterns of possible elite consumption at Cahokia and restricted use of rare species.  相似文献   
157.
The period comprising the end of the Early Neolithic and the Middle Neolithic, dated broadly within the fifth millennium cal BC, corresponds to an interval that remains largely unknown in the extreme north-western tip of Africa. This situation contrasts with that of the Early Neolithic, a period characterised by the earliest evidence of the diffusion of a productive economy, cultivated plants and domestic animals. The paucity of data for these later phases can be explained in part by the lack of secure contexts and sequences based on radiocarbon datings of short-lived samples. The current study presents the results of the excavations of El-Khil Caves B and C that yield materials allowing re-evaluation of the chronology of a type of ceramic known as Ashakar ware. The study also identifies two traditions in the northern Moroccan Middle Neolithic. The first is heir to the so-called Impressa Mediterranean ware and rooted in the Cardial Neolithic, while the second is characterised by roulette cord impressions, red slip and tunnel lugs and probably rooted in the region of the Sahara, and has no technological precedents in the study area.  相似文献   
158.
The study presents the results of neutron activation analysis (NAA) of contemporary pottery from Tigray Regional State, northern highland Ethiopia. This is the first regional-scale study of ceramic composition of Tigray’s pottery and is part of an ethnoarchaeological study of the material and social contexts of pottery production and consumption in Tigray’s Eastern (Misraqawi), Central (Mehakelegnaw), and North-western (Semien Mi’irabawi) zones. The analysis identifies clear compositional groups with strong regional patterns, an encouraging result for the use of NAA to study Tigray’s ancient pottery trade. Significantly, the study further contributes to discussions of how mutually constituted social identities of potters and consumers affect compositional patterning in the distribution of pottery in market networks.  相似文献   
159.
Four decades have passed since Harlan and Stemler (1976) proposed the eastern Sahelian zone as the most likely center of Sorghum bicolor domestication. Recently, new data on seed impressions on Butana Group pottery, from the fourth millennium BC in the southern Atbai region of the far eastern Sahelian Belt in Africa, show evidence for cultivation activities of sorghum displaying some domestication traits. Pennisetum glaucum may have been undergoing domestication shortly thereafter in the western Sahel, as finds of fully domesticated pearl millet are present in southeastern Mali by the second half of the third millennium BC, and present in eastern Sudan by the early second millennium BC. The dispersal of the latter to India took less than 1000 years according to present data. Here, we review the middle Holocene Sudanese archaeological data for the first time, to situate the origins and spread of these two native summer rainfall cereals in what is proposed to be their eastern Sahelian Sudan gateway to the Red Sea and the Indian Ocean trade.  相似文献   
160.
First visited by westerners in the mid-nineteenth century, Saharan rock art has since received a great deal of attention. The richness and diversity of this region is recognised by the inclusion on the UNESCO World Heritage list of three properties: Tassili-n-Ajjer in Algeria, Tadrart Acacus in Libya, and Ennedi in Chad. The situation in many North African countries now makes this vast region very difficult to access: safety in the field is not guaranteed and few research funds are available. Today, a new generation of African and foreign scientists has no access to rock art sites in the north of the continent and the lack of fieldwork may entail a lack of safeguard and awareness. The growth of digital technologies over the last 15 years has revolutionised methods for recording rock art sites. Digital technologies are also used to mitigate the gap between artworks and accessibility in those countries where turmoil and social instability make fieldwork impossible. However, much of the documentation and most digital recordings of artworks currently available on the Internet lack an archaeological context. Equally, many of these websites barely mention methodological and theoretical aspects. It is also difficult to understand the extent of awareness among local communities in remote areas—sometimes suffering a digital and linguistic divide—and if (and how) they are genuinely able to exploit these digital resources. Here, I collate some examples from different parts of the Sahara illustrating that the recording, management and dissemination of rock art still present highs and lows. I argue that we should share theories and methods within the digital scientific community, with a view to adopting a shared nomenclature and a public thesaurus, making our cataloguing criteria explicit and, finally, developing an ethical code of conduct involving local communities.  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