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   706286篇
  免费   48900篇
  国内免费   1306篇
耳鼻咽喉   9177篇
儿科学   23271篇
妇产科学   17606篇
基础医学   110420篇
口腔科学   19970篇
临床医学   63785篇
内科学   134386篇
皮肤病学   16167篇
神经病学   49478篇
特种医学   25756篇
外国民族医学   76篇
外科学   104598篇
综合类   14819篇
现状与发展   2篇
一般理论   160篇
预防医学   51402篇
眼科学   16322篇
药学   53991篇
  3篇
中国医学   2361篇
肿瘤学   42742篇
  2021年   5445篇
  2018年   7866篇
  2017年   6112篇
  2016年   6827篇
  2015年   7556篇
  2014年   10283篇
  2013年   15397篇
  2012年   20511篇
  2011年   21507篇
  2010年   12738篇
  2009年   11938篇
  2008年   19999篇
  2007年   21529篇
  2006年   21924篇
  2005年   20472篇
  2004年   20011篇
  2003年   18958篇
  2002年   18472篇
  2001年   36335篇
  2000年   36906篇
  1999年   30385篇
  1998年   7879篇
  1997年   6668篇
  1996年   6972篇
  1995年   6631篇
  1994年   6099篇
  1993年   5591篇
  1992年   22977篇
  1991年   22933篇
  1990年   22324篇
  1989年   22083篇
  1988年   20042篇
  1987年   19430篇
  1986年   18476篇
  1985年   17313篇
  1984年   12703篇
  1983年   10742篇
  1982年   5923篇
  1979年   11527篇
  1978年   8133篇
  1977年   6836篇
  1976年   6595篇
  1975年   7268篇
  1974年   8501篇
  1973年   8144篇
  1972年   7662篇
  1971年   7131篇
  1970年   6883篇
  1969年   6311篇
  1968年   5783篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Biliopancreatic diversion is a very effective method for weight reduction. In some instances it is too effective and needs to be revised.  相似文献   
82.
83.
In 1983, 1623 primary and secondary schoolchildren took part in a health survey which was organized by the Busselton Population Studies Group. Age, sex, weight, height and country of birth were recorded for each child. Where possible, the country of birth of parents and the occupation of the father were extracted from previous Busselton surveys of adults. Compared with Perth schoolchildren, the difference in the attained weight and height of Busselton children at any age was small. This was so even though the two communities differ in location (rural compared with metropolitan), in ethnic origin (mainly British compared with diverse origins) and, probably, in social-rank distribution. Data from the two communities showed that a similar small secular increase in height had occurred since 1970/1971. This increase averaged at 1.2 cm for children at each year of age in Busselton and 1.5 cm to 1.6 cm for children in Perth.  相似文献   
84.
85.
A novel approach for modelling the biological activity of organic molecules, which requires simultaneous consideration of the influence of all factors (topological, steric, hydrophobic, and electronic) that determine the bioactivity, is used to study the interaction of a series of benzoates with anti-p-(p'-azophenylazo)benzoate antibody. The results obtained suggest that this biological interaction proceeds by a two-step stereospecific mechanism. The first step requires a geometrical correspondence between the benzoates and the cavity in the biomacromolecule, which enables the pharmacophore to come into close contact with the receptor. The second step is the orbitally controlled electronic interaction between the active parts of the benzoates and the antibody. The electronic interaction results from pi-charge transfer from the pharmacophore to the biomacromolecule and from the formation of pi-complexes. A proposed mathematical model for this biological interaction exhibits some statistical advantages over existing models.  相似文献   
86.
87.
88.
Bromocriptine (0.5 mg/kg) and apomorphine (0.03 mg/kg) exert moderate aphrodisiac effect in sexually sluggish rats. This effect appears rapidly and reaches its peak within 24 h. Amphetamine (2 mg/kg) acts similarly but with a more rapid onset and offset of the effect. A single dose of (-)deprenyl, a selective inhibitor of MAO-B, exerts a much more potent effect in this test.  相似文献   
89.
90.
We review evidence suggesting that deaf speakers do not move their articulators toward the following open posture throughout closure and report results from a preliminary cinefluorographic study. Two prelingually deaf and two hearing speakers produced two different strings of alternating heterogeneous monosyllables as though speaking in time with a metronome (the so-called P-center task). Events traditionally associated with vowel production appeared evenly timed throughout the productions, and, in general, the deaf speakers performed similarly to the hearing speakers. We relate the results to Fowler's (1983) interpretation of the P-center phenomenon as an indicant of continuous vowel production.  相似文献   
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