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   726689篇
  免费   50413篇
  国内免费   1374篇
耳鼻咽喉   9490篇
儿科学   23986篇
妇产科学   17907篇
基础医学   112536篇
口腔科学   20446篇
临床医学   65650篇
内科学   138944篇
皮肤病学   16623篇
神经病学   50579篇
特种医学   26684篇
外国民族医学   77篇
外科学   108503篇
综合类   15098篇
现状与发展   2篇
一般理论   175篇
预防医学   52421篇
眼科学   17034篇
药学   55727篇
  3篇
中国医学   2394篇
肿瘤学   44197篇
  2021年   6318篇
  2019年   6163篇
  2018年   8717篇
  2017年   6641篇
  2016年   7407篇
  2015年   8133篇
  2014年   11160篇
  2013年   16415篇
  2012年   22071篇
  2011年   22999篇
  2010年   13499篇
  2009年   12635篇
  2008年   21117篇
  2007年   22597篇
  2006年   22919篇
  2005年   21309篇
  2004年   20773篇
  2003年   19612篇
  2002年   19033篇
  2001年   36782篇
  2000年   37335篇
  1999年   30777篇
  1998年   8015篇
  1997年   6784篇
  1996年   7088篇
  1995年   6752篇
  1994年   6184篇
  1992年   23191篇
  1991年   23167篇
  1990年   22522篇
  1989年   22270篇
  1988年   20212篇
  1987年   19602篇
  1986年   18629篇
  1985年   17467篇
  1984年   12791篇
  1983年   10851篇
  1982年   5997篇
  1979年   11626篇
  1978年   8189篇
  1977年   6886篇
  1976年   6637篇
  1975年   7318篇
  1974年   8547篇
  1973年   8212篇
  1972年   7702篇
  1971年   7168篇
  1970年   6925篇
  1969年   6334篇
  1968年   5820篇
排序方式: 共有10000条查询结果,搜索用时 12 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