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   1266691篇
  免费   95171篇
  国内免费   1618篇
耳鼻咽喉   16360篇
儿科学   41067篇
妇产科学   34987篇
基础医学   189820篇
口腔科学   34770篇
临床医学   118071篇
内科学   248387篇
皮肤病学   27382篇
神经病学   102068篇
特种医学   47015篇
外国民族医学   265篇
外科学   178801篇
综合类   25771篇
现状与发展   3篇
一般理论   568篇
预防医学   104802篇
眼科学   28083篇
药学   92830篇
  7篇
中国医学   2082篇
肿瘤学   70341篇
  2018年   13593篇
  2017年   10465篇
  2016年   11420篇
  2015年   13189篇
  2014年   18134篇
  2013年   27644篇
  2012年   37818篇
  2011年   40197篇
  2010年   23196篇
  2009年   22372篇
  2008年   37929篇
  2007年   40530篇
  2006年   40085篇
  2005年   39233篇
  2004年   37648篇
  2003年   36047篇
  2002年   34939篇
  2001年   56082篇
  2000年   57096篇
  1999年   48145篇
  1998年   13412篇
  1997年   12239篇
  1996年   12648篇
  1995年   11924篇
  1994年   11111篇
  1993年   10408篇
  1992年   38215篇
  1991年   37691篇
  1990年   36455篇
  1989年   35275篇
  1988年   32699篇
  1987年   32038篇
  1986年   30529篇
  1985年   28790篇
  1984年   21948篇
  1983年   19197篇
  1982年   11366篇
  1981年   10322篇
  1979年   20944篇
  1978年   15394篇
  1977年   12791篇
  1976年   11845篇
  1975年   12810篇
  1974年   15588篇
  1973年   15362篇
  1972年   14513篇
  1971年   13554篇
  1970年   12787篇
  1969年   12068篇
  1968年   11234篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
75.
76.
77.
Background: Excessive drinking is commonplace at UK Universities. Individuals may misperceive how much they drink compared to others and are less likely to think that they will suffer adverse consequences. Young people often distance themselves and their friends from ‘problem drinkers’. Objectives: The aim of the study was to explore how student drinkers compared their own drinking behaviors to the drinking behaviors of others. Methods: An online survey was completed by 416 students aged 18–30 (68.5% female). They were asked ‘how do you think your drinking compares with other people like you?' and ‘how do you think your behavior when you drink compares with other people like you?’ Answers were subjected to thematic analysis. Results: The first main theme was about ‘identification as a ‘good’ drinker’. Participants suggested their own behavior when drinking was similar to their sober behavior. Further, they viewed themselves as more able to maintain a balance between staying in control and having fun while drinking. The second main theme was about ‘distancing from being a ‘bad’ drinker. Participants distanced themselves from negative prototypical drinkers, such compulsive or anti-social drinkers. They also attributed their own drinking behaviors to situational factors, but described other people as intentionally violent or aggressive. Conclusions/Importance: These findings may explain the failure of some health messages to change drinking behaviors. If drinkers perceive that their behavior when they drink is better than other people's then they may discount intervention messages. Targeting these biases could be incorporated into future interventions.  相似文献   
78.
Pharmaceuticals are ubiquitous in the natural environment with concentrations expected to rise as human population increases. Environmental risk assessments are available for a small portion of pharmaceuticals in use, raising concerns over the potential risks posed by other drugs that have little or no data. With >1900 active pharmaceutical ingredients in use, it would be a major task to test all of the compounds with little or no data. Desk-based prioritization studies provide a potential solution by identifying those substances that are likely to pose the greatest risk to the environment and which, therefore, need to be considered a priority for further study. The aim of this review was to (1) provide an overview of different prioritization exercises performed for pharmaceuticals in the environment and the results obtained; and (2) propose a new holistic risk-based prioritization framework for drugs in the environment. The suggested models to underpin this framework are discussed in terms of validity and applicability. The availability of data required to run the models was assessed and data gaps identified. The implementation of this framework may harmonize pharmaceutical prioritization efforts and ensure that, in the future, experimental resources are focused on molecules, endpoints, and environmental compartments that are biologically relevant.  相似文献   
79.
80.
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