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   481篇
  免费   17篇
  2023年   3篇
  2020年   5篇
  2019年   17篇
  2018年   14篇
  2017年   18篇
  2016年   28篇
  2015年   19篇
  2014年   10篇
  2013年   124篇
  2012年   15篇
  2011年   16篇
  2010年   13篇
  2009年   9篇
  2008年   17篇
  2007年   10篇
  2006年   12篇
  2005年   7篇
  2004年   10篇
  2003年   4篇
  2002年   7篇
  2001年   4篇
  2000年   9篇
  1999年   10篇
  1998年   9篇
  1997年   7篇
  1996年   8篇
  1995年   2篇
  1994年   9篇
  1993年   5篇
  1992年   3篇
  1991年   7篇
  1990年   3篇
  1989年   3篇
  1988年   4篇
  1987年   5篇
  1986年   6篇
  1985年   6篇
  1984年   6篇
  1983年   4篇
  1982年   5篇
  1981年   3篇
  1978年   3篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
  1973年   3篇
  1972年   2篇
  1971年   2篇
  1970年   1篇
排序方式: 共有498条查询结果,搜索用时 15 毫秒
1.
While food allergy prevalence has been studied at the national level, we know little of food allergy prevalence or perceptions of prevalence/management at the local level. This paper uses Waterloo Region as a case study to 1) document self-reported individual and household food allergy and sensitivity prevalence at the local level; 2) investigate perceptions of food allergy prevalence; and 3) explore perceived confidence in anaphylaxis management. Survey data were collected from January to March 2019. Respondents (n = 500) self-reported individual and household food allergy and sensitivity, estimated the percentage of Canadians with food allergy, and were queried about their knowledge of food allergy management. Prevalence estimates were weighted to the structure of the 2016 Canadian Census, and univariate and bivariate analysis were conducted. Prevalence of self-reported food allergy was 12.1% (95%CI, 8.8%-15.3%), and prevalence of self-reported food sensitivity was 26.3% (95%CI, 21.9%-30.7%). When asked to estimate the percentage of Canadians with food allergy, the mean perceived percentage was 35.1% (SD = 22.96). Self-reported prevalence of food allergy appears higher in Waterloo Region, and the estimated percentage of Canadians with food allergy is inflated. Understanding prevalence and perceptions at the local level is important for targeted allocation of public health resources to ensure safe spaces for individuals with food allergy.  相似文献   
2.
3.
Ancient Mesopotamian scholars examined problematic aspects of male erotic desire within the discourse of divination. They documented an array of sexual acts, reading each as an omen, a sign signifying an aspect of the future. Guinan shows that the omens are informed by a coherent perspective and, in general, are concerned with the impact of erotic desire on notions of male identity and expectations of gender hierarchy. The omens oppose masculine hegemony and male/female eroticism in such a way that the denial of one is the assertion of the other. In these omens, masculine power and agency are both expressed and preserved by the disavowal of erotic interactions with women.  相似文献   
4.
5.
6.
Many timber finds lack some or all of the outer, sapwood rings formed in the years just before felling. In order to estimate felling date once the outermost remaining ring has been dated, it is necessary to estimate the number of sapwood rings originally present. Methods doing this for oak are reviewed in the light of an intensive study of living trees at one site and an extensive study of 175 samples from living trees in North Wales and northwest England. Some methods reported in the literature are found to be invalid. A method reported by Hollstein (1965) is most reliable, with modifications for known variations in sapwood number with position in the tree. At present the best available estimate is that a value of 30 sapwood rings be used (95% confidence limits: 19–50).  相似文献   
7.
8.
9.
10.
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