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   862873篇
  免费   82010篇
  国内免费   16060篇
耳鼻咽喉   11512篇
儿科学   22590篇
妇产科学   20948篇
基础医学   117508篇
口腔科学   23803篇
临床医学   101872篇
内科学   159127篇
皮肤病学   18312篇
神经病学   62373篇
特种医学   30938篇
外国民族医学   159篇
外科学   123225篇
综合类   42767篇
现状与发展   85篇
一般理论   211篇
预防医学   68130篇
眼科学   21243篇
药学   66669篇
  164篇
中国医学   11925篇
肿瘤学   57382篇
  2023年   8860篇
  2022年   11406篇
  2021年   17681篇
  2020年   15547篇
  2019年   13448篇
  2018年   20036篇
  2017年   17924篇
  2016年   18586篇
  2015年   22627篇
  2014年   29371篇
  2013年   33781篇
  2012年   35437篇
  2011年   38331篇
  2010年   27186篇
  2009年   26486篇
  2008年   30807篇
  2007年   30832篇
  2006年   31647篇
  2005年   29685篇
  2004年   24817篇
  2003年   22799篇
  2002年   21418篇
  2001年   31633篇
  2000年   32124篇
  1999年   28478篇
  1998年   11107篇
  1997年   10207篇
  1996年   9698篇
  1995年   8814篇
  1994年   7576篇
  1993年   6505篇
  1992年   18641篇
  1991年   18844篇
  1990年   18538篇
  1989年   17694篇
  1988年   16286篇
  1987年   15921篇
  1986年   14855篇
  1985年   13984篇
  1984年   10328篇
  1983年   8908篇
  1979年   9718篇
  1978年   7108篇
  1977年   5990篇
  1975年   6535篇
  1974年   7810篇
  1973年   7266篇
  1972年   7100篇
  1971年   6792篇
  1970年   6297篇
排序方式: 共有10000条查询结果,搜索用时 45 毫秒
91.
92.
93.
94.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy.  相似文献   
95.
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc.  相似文献   
96.
97.
98.
99.
Formulae for the calculation of the count of microorganisms isolated from natural bacterial biocenoses of a child's body have been derived. The authors suggest a variant of simplified drip method for the computation of microorganism colonies in solid media. The described method helps cut down the nutrient media consumption at least 3-fold and is time-saving.  相似文献   
100.
Perceptual asymmetry on a series of four specially constructed dichotic word tests was found to change as a function of the emotional quality of the words in the tests (P = 0.05). This was most pronounced in the case of positively valued words which produced an increase in asymmetry consistent with facilitated left-hemisphere function (P less than 0.004). Changes in asymmetry with emotion differed as a function of personality characteristics of the subjects, with repressors and high anxious subjects showing an increase with emotion while true low anxious subjects showed a decrease (P less than 0.02). Personality groups also differed in asymmetry on an emotionally neutral test (P less than 0.04) and in changes in asymmetry over time independent of emotion (P less than 0.001). These data suggest that emotion mediated activation of the left hemisphere may facilitate information processing within that hemisphere. Moreover, they indicate that dichotic listening tests may provide a non-invasive and inexpensive method for assessing emotion mediated changes in brain state that are clinically relevant.  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