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   1936篇
  免费   16篇
  1952篇
  2024年   6篇
  2023年   23篇
  2022年   5篇
  2021年   9篇
  2020年   37篇
  2019年   33篇
  2018年   348篇
  2017年   256篇
  2016年   286篇
  2015年   58篇
  2014年   41篇
  2013年   137篇
  2012年   57篇
  2011年   176篇
  2010年   184篇
  2009年   51篇
  2008年   82篇
  2007年   79篇
  2006年   2篇
  2005年   30篇
  2004年   9篇
  2003年   4篇
  2002年   5篇
  2001年   9篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   3篇
  1996年   2篇
  1995年   7篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1982年   1篇
  1979年   1篇
排序方式: 共有1952条查询结果,搜索用时 0 毫秒
81.
There is limited available data on the environmental context of the arrival of the first anatomically modern humans (AMH) in North Africa, and subsequent Paleolithic and Neolithic occupations within this region. Microvertebrates such as rodents, shrews, amphibians, and squamates are known to be good indicators of climate and landscape changes. They also represent continental paleoecological records that can be directly related to human occupations. Moreover, faunas and humans have been subjected to several dispersal waves through similar routes, and some rodents may present anthropophilous behavior. Therefore, by understanding the dispersal pattern and pathways of these microvertebrates, it is possible to propose scenarios for human dispersal events. In this study we took the rich microfaunal assemblages from the Témara region, Atlantic Morocco (El Harhoura 2 and El Mnasra Caves), and placed them within a broader synthesis, in order to highlight the role of microvertebrates in providing a better understanding of the human-environment relationship during the Late Quaternary in North Africa.  相似文献   
82.
83.
84.
85.
86.
87.
    
Quaternary stratigraphy and sea level changes have been extensively investigated in many areas of the Mediterranean. However, numerical dating of coastal deposits and the associated paleoenvironmental information are limited for the coasts of Cyprus, principally based on radiometric and radiation-exposure geochronological techniques on fossils which bear a range of limitations and uncertainties. As such, optically stimulated luminescence (OSL) dating techniques are deemed to be the most suitable in direct dating of the coastal sediments of Cyprus. In the southeastern Cyprus, coastal dunes (aeolianites) now forming elongated ridges appear as morphological features running parallel to the current shoreline presenting an indicator of sea level and climate changes of great paleoenvironmental significance. We present our first chronological results for the exposed aeolianites and underlying littoral deposits formed along the southeastern coastal Cyprus ranging from 78.4 ± 9.9 to 56.2 ± 7.4 ka. The post-infrared–infrared stimulated luminescence (pIR-IRSL) revealed that dune formation took place during the marine isotope stages (MISs) 3, 4, and possibly 5a. Late Holocene reworking is proposed for a distinctively isolated dune with an age of ~1.3 ka ago. This study also showed that pIR-IRSL dating of feldspars may be a reliable alternative to quartz OSL dating when the quartz luminescence characteristics are unsuitable.  相似文献   
88.
The place of propaganda in a democratic society has been discussed long before the age of fake news, as the heated debate on this issue that took place in the UK and other democracies from around 1914 to 1950 clearly shows. Drawing upon a variety of published and archival sources, the article examines the changing views of British political elites, intellectuals, publicity experts and the public on the proper role of government in the public sphere, while discussing their influence on government policies and exploring the light they shed on British—and, more broadly, liberal democratic—culture and identity.  相似文献   
89.
90.
This paper explores regional (département or NUTS3) income inequality in France between 1860 and 1954. To this end we first document the existing evidence, evaluate the estimation methods and findings, assess the suitability of each approach and address potential concerns. We then present our own subnational estimates of per-capita income, derived following Geary and Stark. Overall, we find that indirect estimation (or top-down) methods provide somewhat differing results, thereby calling into question the validity of some of these approaches. Our estimates, meanwhile, appear to fit reasonably well with direct estimations (or bottom-up) of value-added and income and provide evidence in support of a decline in regional inequality over the period of study.  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