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   2473篇
  免费   6篇
  国内免费   1篇
化学工业   15篇
金属工艺   2篇
机械仪表   5篇
建筑科学   11篇
能源动力   2篇
轻工业   54篇
石油天然气   1篇
无线电   2篇
一般工业技术   3篇
冶金工业   2379篇
原子能技术   1篇
自动化技术   5篇
  2020年   3篇
  2017年   5篇
  2016年   2篇
  2015年   2篇
  2013年   8篇
  2012年   2篇
  2011年   3篇
  2010年   9篇
  2009年   4篇
  2008年   2篇
  2007年   4篇
  2006年   6篇
  2005年   3篇
  2003年   7篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1999年   68篇
  1998年   722篇
  1997年   398篇
  1996年   274篇
  1995年   168篇
  1994年   114篇
  1993年   159篇
  1992年   17篇
  1991年   19篇
  1990年   32篇
  1989年   28篇
  1988年   32篇
  1987年   14篇
  1986年   20篇
  1985年   14篇
  1984年   2篇
  1983年   4篇
  1982年   11篇
  1981年   17篇
  1980年   26篇
  1979年   2篇
  1978年   9篇
  1977年   77篇
  1976年   179篇
  1975年   3篇
  1974年   1篇
  1968年   1篇
  1965年   2篇
  1962年   1篇
  1955年   1篇
排序方式: 共有2480条查询结果,搜索用时 15 毫秒
11.
The nature of disturbed thinking is explained from two different psychological perspectives and six major types of thought disorder are presented, classified, and discussed. The overlap between these different types of thought disturbance and some possible functions of disturbed thinking are outlined. A heuristic model for detecting thought disorder is presented; and, in addition, some complex conceptual and research issues involved with investigating and systematizing knowledge about disturbed thinking are explained.  相似文献   
12.
13.
14.
15.
16.
Jejunal lamina propria plasma cells and eosinophils and intraepithelial lymphocytes were raised in coeliac children on gluten-containing diets, but only intraepithelial lymphocytes were increased in patients on gluten-free diets. In contrast, lamina propria lymphocytes were reduced in children with coeliad disease on gluten-containing diets but were normal in paitents on gluten-free diets. In children with coeliac disease who were studied serially, lamina propria plasma cells and eosinophils and intraepithelial lymphocytes increased, and lamina propria lymphocytes decreased, within three months of the reintroduction of gluten to the diet. These observations are essentially similar to those made in the adult form of the disease and suggest that more than one type of immunological reaction is involved in the pathogenesis of the jejunal lesion.  相似文献   
17.
We studied in 130 parturients during childbirth the effects of general anaesthesia by Alfatesine on the state of the foetus at birth. The examinations took into account the APGAR score, blood gas analysis, pH, bases excess in the umbilical artery and vein and the foetal EEG. The subjects are divided into three groups: prophylactic caesarians, extractions during labor in the absence of any foetal distress and extractions for reasons of acute or chronic foetal distress. The results are evaluated in comparison with the same tests conducted on a series of newborn infants in normal conditions and without anaesthesia. The APGAR score is hardly affected by the Alfatesine; the EEG is perturbed (but without any clinical manifestations) during the two hours following delivery. However, theses modifications are less pronounced than those observed with barbiturates. The study of blood gases and pH shows lower values under anaesthesia than without.  相似文献   
18.
19.
20.
Cytophotometric, interferometric and autoradiographic methods were applied to evaluate hyperchromic motoneurons (HM) from spinal cord of mice which were allowed to swim for 4 hours. The HM in comparison with the normochromic motor nerve cells are characterized by a higher RNA content and a lower dry weight of perikaria. The autoradiographic data with H3-uridane make it possible to suggest that RNA exchange between the nucleus and cytoplasm of HM is accelerated. The mode of distribution of labelled proteins along the sciatic nerve 6 days after the local injection of H3-leucine in the ventral horn of L3--L4 spinal cord segments allows to conclude that the amount of protein transported with the slow component of axonal flow in the cases connected with the increase of the number of HM in corresponding nuclei is changed.  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