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   1867363篇
  免费   139632篇
  国内免费   4341篇
耳鼻咽喉   23676篇
儿科学   60334篇
妇产科学   49829篇
基础医学   264358篇
口腔科学   52618篇
临床医学   168425篇
内科学   369481篇
皮肤病学   40959篇
神经病学   148367篇
特种医学   69571篇
外国民族医学   255篇
外科学   284201篇
综合类   41895篇
现状与发展   6篇
一般理论   808篇
预防医学   140812篇
眼科学   43784篇
药学   135883篇
  8篇
中国医学   4770篇
肿瘤学   111296篇
  2021年   15553篇
  2019年   16257篇
  2018年   23216篇
  2017年   17827篇
  2016年   19393篇
  2015年   22292篇
  2014年   31212篇
  2013年   45322篇
  2012年   63536篇
  2011年   67353篇
  2010年   39521篇
  2009年   36858篇
  2008年   62950篇
  2007年   66850篇
  2006年   66963篇
  2005年   64571篇
  2004年   62425篇
  2003年   59092篇
  2002年   56960篇
  2001年   93381篇
  2000年   94818篇
  1999年   78694篇
  1998年   22121篇
  1997年   19334篇
  1996年   19299篇
  1995年   18399篇
  1994年   16812篇
  1993年   15474篇
  1992年   58384篇
  1991年   56230篇
  1990年   53848篇
  1989年   51557篇
  1988年   47003篇
  1987年   45804篇
  1986年   43087篇
  1985年   40927篇
  1984年   30614篇
  1983年   26164篇
  1982年   15454篇
  1981年   13782篇
  1979年   26222篇
  1978年   18406篇
  1977年   15695篇
  1976年   14602篇
  1975年   15153篇
  1974年   18207篇
  1973年   17461篇
  1972年   16054篇
  1971年   14760篇
  1970年   13726篇
排序方式: 共有10000条查询结果,搜索用时 547 毫秒
51.
Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day''s more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form.  相似文献   
52.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
53.
54.
David Marr's three-level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal-mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily.  相似文献   
55.
56.
57.
58.
59.
60.
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