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   709561篇
  免费   49036篇
  国内免费   1320篇
耳鼻咽喉   9196篇
儿科学   23370篇
妇产科学   17754篇
基础医学   110880篇
口腔科学   19998篇
临床医学   64008篇
内科学   135383篇
皮肤病学   16204篇
神经病学   49688篇
特种医学   25880篇
外国民族医学   76篇
外科学   105022篇
综合类   14830篇
现状与发展   2篇
一般理论   161篇
预防医学   51456篇
眼科学   16417篇
药学   54157篇
  3篇
中国医学   2362篇
肿瘤学   43070篇
  2021年   5510篇
  2018年   7928篇
  2017年   6173篇
  2016年   6889篇
  2015年   7619篇
  2014年   10351篇
  2013年   15495篇
  2012年   20698篇
  2011年   21691篇
  2010年   12809篇
  2009年   12020篇
  2008年   20171篇
  2007年   21700篇
  2006年   22084篇
  2005年   20611篇
  2004年   20183篇
  2003年   19099篇
  2002年   18610篇
  2001年   36441篇
  2000年   37044篇
  1999年   30474篇
  1998年   7914篇
  1997年   6686篇
  1996年   6994篇
  1995年   6643篇
  1994年   6124篇
  1993年   5611篇
  1992年   23045篇
  1991年   23004篇
  1990年   22396篇
  1989年   22152篇
  1988年   20111篇
  1987年   19487篇
  1986年   18525篇
  1985年   17343篇
  1984年   12735篇
  1983年   10781篇
  1982年   5941篇
  1979年   11553篇
  1978年   8141篇
  1977年   6857篇
  1976年   6601篇
  1975年   7275篇
  1974年   8513篇
  1973年   8155篇
  1972年   7670篇
  1971年   7132篇
  1970年   6884篇
  1969年   6322篇
  1968年   5790篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
142.
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   
143.
144.
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   
145.
The influence of food and water intake on mefenamic acid (N-2,3-xylylanthranilic acid) bioavailability from commercial capsules of high bioavailability was studied in four healthy male volunteers. The drug was administered as a single oral dose of 250 mg, under fasting or nonfasting conditions, and a 4 X 4 Latin-square design was used. Eight blood samples were collected over a 24-h period following drug administration, and the drug plasma concentrations were determined by HPLC. The bioavailability of mefenamic acid from capsules was markedly influenced in the fasting subjects by the water but not by the food intake. A good correlation was found between the bioavailability and amount of water ingested with the drug in the fasting subjects. The area under the plasma concentration-time curve (AUC0-infinity) of mefenamic acid was highest when the capsule was taken with 50 mL of water or immediately after a meal. Increasing the amount of water from 50 to 500 mL in the fasting subjects caused a significant reduction in AUC0-infinity.  相似文献   
146.
147.
148.
149.
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   
150.
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