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   2505792篇
  免费   182661篇
  国内免费   3872篇
耳鼻咽喉   34307篇
儿科学   80343篇
妇产科学   66153篇
基础医学   369249篇
口腔科学   67206篇
临床医学   228255篇
内科学   488107篇
皮肤病学   54091篇
神经病学   200711篇
特种医学   93184篇
外国民族医学   501篇
外科学   376141篇
综合类   49926篇
现状与发展   13篇
一般理论   1045篇
预防医学   195994篇
眼科学   58321篇
药学   185660篇
  11篇
中国医学   4774篇
肿瘤学   138333篇
  2021年   21373篇
  2019年   21886篇
  2018年   29985篇
  2017年   22408篇
  2016年   25214篇
  2015年   28517篇
  2014年   40252篇
  2013年   60667篇
  2012年   83844篇
  2011年   89315篇
  2010年   52740篇
  2009年   49733篇
  2008年   83862篇
  2007年   89479篇
  2006年   89816篇
  2005年   87494篇
  2004年   83594篇
  2003年   80624篇
  2002年   78035篇
  2001年   110666篇
  2000年   113083篇
  1999年   95352篇
  1998年   29025篇
  1997年   25405篇
  1996年   25555篇
  1995年   24144篇
  1994年   22220篇
  1993年   20967篇
  1992年   73415篇
  1991年   71384篇
  1990年   69588篇
  1989年   66818篇
  1988年   61405篇
  1987年   60216篇
  1986年   56350篇
  1985年   54225篇
  1984年   40625篇
  1983年   34663篇
  1982年   21384篇
  1979年   36854篇
  1978年   26670篇
  1977年   22110篇
  1976年   21152篇
  1975年   22472篇
  1974年   26891篇
  1973年   25397篇
  1972年   23728篇
  1971年   22487篇
  1970年   20605篇
  1969年   19682篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
The purpose of this study was to evaluate a single-session peer-led safer sex intervention, based on the Information-Motivation-Behavioral Skills theoretical model, for college students residing in campus residence halls. Participants (N = 108) were assigned to either an hour long control or 5-module intervention session. Compared to the control condition, the intervention increased participants’ information and women’s subjective norms about preventative behavior. Both the control and intervention sessions increased intentions to perform preventative behaviors (e.g., keep condoms available). These preliminary results suggest that this intervention is promising for increasing constructs associated with safer sexual behavior and could easily be implemented by residence hall staff.  相似文献   
994.
An inverse relationship between workplace status and morbidity is well established; higher job status has been associated with reduced risks of heart disease, hypertension, and injury. Most research on job status, however, has focused on salaried populations, and it remains unclear whether job status operates similarly among hourly workers. Our objectives were to examine whether hourly status itself influences risk of hypertension after adjustment for socioeconomic confounders, and to explore the role of fine-scale job grade on hypertension incidence within hourly and salaried groups. We examined data for 14,999 aluminum manufacturing employees in 11 plants across the U.S., using logistic regression with adjustment for age, sex, race/ethnicity and other individual characteristics. Propensity score restriction was used to identify comparable groups of hourly and salaried employees, reducing confounding by sociodemographic characteristics. Job grade (coded 1 through 30, within hourly and salaried groups) was examined as a more refined measure of job status. Hourly status was associated with an increased risk of hypertension, after propensity restriction and adjustment for confounders. The observed effect of hourly status was stronger among women, although the propensity-restricted cohort was disproportionately male (96%). Among salaried workers, higher job grade was not consistently associated with decreased risk; among hourly employees, however, there was a significant trend, with higher job grades more protective against hypertension. Increasing the stringency of hypertension case criteria also increased the risk of severe or persistent hypertension for hourly employees.  相似文献   
995.
996.
997.
998.
999.
1000.
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