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   707642篇
  免费   48989篇
  国内免费   1309篇
耳鼻咽喉   9317篇
儿科学   23340篇
妇产科学   17609篇
基础医学   110622篇
口腔科学   20031篇
临床医学   63871篇
内科学   134767篇
皮肤病学   16176篇
神经病学   49602篇
特种医学   25805篇
外国民族医学   76篇
外科学   104653篇
综合类   14825篇
现状与发展   2篇
一般理论   160篇
预防医学   51449篇
眼科学   16340篇
药学   54114篇
  3篇
中国医学   2361篇
肿瘤学   42817篇
  2019年   5461篇
  2018年   7888篇
  2017年   6130篇
  2016年   6854篇
  2015年   7573篇
  2014年   10301篇
  2013年   15419篇
  2012年   20553篇
  2011年   21589篇
  2010年   12778篇
  2009年   11969篇
  2008年   20075篇
  2007年   21592篇
  2006年   21985篇
  2005年   20536篇
  2004年   20072篇
  2003年   19018篇
  2002年   18526篇
  2001年   36380篇
  2000年   36961篇
  1999年   30433篇
  1998年   7894篇
  1997年   6678篇
  1996年   6991篇
  1995年   6643篇
  1994年   6117篇
  1993年   5609篇
  1992年   23018篇
  1991年   22969篇
  1990年   22370篇
  1989年   22122篇
  1988年   20078篇
  1987年   19464篇
  1986年   18497篇
  1985年   17323篇
  1984年   12718篇
  1983年   10751篇
  1982年   5929篇
  1979年   11534篇
  1978年   8141篇
  1977年   6844篇
  1976年   6599篇
  1975年   7275篇
  1974年   8507篇
  1973年   8148篇
  1972年   7665篇
  1971年   7133篇
  1970年   6887篇
  1969年   6314篇
  1968年   5790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