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   340篇
  免费   20篇
  360篇
  2023年   2篇
  2022年   5篇
  2021年   8篇
  2020年   3篇
  2019年   4篇
  2018年   7篇
  2017年   6篇
  2016年   6篇
  2015年   16篇
  2014年   23篇
  2013年   24篇
  2012年   32篇
  2011年   35篇
  2010年   25篇
  2009年   20篇
  2008年   23篇
  2007年   17篇
  2006年   19篇
  2005年   16篇
  2004年   11篇
  2003年   9篇
  2002年   7篇
  2001年   4篇
  2000年   2篇
  1999年   1篇
  1998年   7篇
  1997年   3篇
  1996年   4篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1991年   1篇
  1989年   1篇
  1987年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   2篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
排序方式: 共有360条查询结果,搜索用时 0 毫秒
351.
352.
This paper examines whether obesity is associated with the likelihood of arrest. We hypothesize that obese individuals are less likely to commit crime and be arrested because their body weights may prevent them from successfully engaging in certain criminal activities, particularly those that are physically intensive. To test this hypothesis, we use the National Longitudinal Survey of Youth 1997 and panel data techniques and find that obesity is negatively related to arrest. In one specification, for example, we found that the odds of an obese man being arrested are 64% of those of a healthy weight man. The social costs of obesity may be overstated if obesity reduces the likelihood of arrest because the obese are less criminally active.  相似文献   
353.
Freddy De Bock 《Geobios》1982,15(6):845-871
The Silurian-Devonian boundary beds of the southeastern Montagne Noire contain few but well-preserved Chitinozoans. A total of 20 species have been recognized. We distinguish 4 assemblages which characterize the Upper Ludlovian, the Pridolian and the Lochkovian sediments.  相似文献   
354.
355.
356.
Helicobacter equorum colonizes the caecum, colon and rectum of horses. The agent is highly prevalent in <6-month-old foals. In adult horses, the prevalence of H. equorum seems to be rather low, but these animals may harbour low, subdetectable numbers of this microorganism in their intestines. So far, no association could be made between the presence of H. equorum and clinical disease or intestinal lesions in adult horses. Further research is necessary to elucidate the pathogenic potential of this bacterial species towards young foals. Helicobacter equorum DNA was not detected in human faeces, indicating that this microorganism does not commonly spread from horses towards humans.  相似文献   
357.
358.
An adult male of a newly discovered strepsipteran species from Brazil— Bahiaxenos relictus— is described. A new family Bahiaxenidae is suggested based on cladistic analyses of comprehensive morphological data sets with a broad taxon sampling including the stem group. It is unambiguously placed as the sister group of all other extant families of Strepsiptera. Bahiaxenos relictus is the only species of basal, i.e. non-stylopidian, Strepsiptera occurring in the New World. It appears to be a relict taxon that has survived in the fossil sand dunes of the São Francisco River (Bahia State). The loss of the 8th antennomere and the greatly reduced labrum are autapomorphies of Strepsiptera s.s . excluding Bahiaxenidae. The sister group relationship between†Protoxenidae and the remaining Strepsiptera, and between † Cretostylops and a clade comprising † Mengea and Strepsiptera s.s. , is confirmed, as is the monophyly of Stylopidia and Stylopiformia.  相似文献   
359.
360.
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