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   1044篇
  免费   0篇
化学工业   11篇
能源动力   1篇
轻工业   2篇
冶金工业   1029篇
自动化技术   1篇
  2023年   1篇
  2022年   1篇
  2019年   1篇
  2010年   1篇
  2009年   1篇
  2008年   1篇
  2005年   2篇
  2003年   1篇
  1999年   18篇
  1998年   307篇
  1997年   202篇
  1996年   117篇
  1995年   68篇
  1994年   59篇
  1993年   54篇
  1992年   7篇
  1991年   15篇
  1990年   8篇
  1989年   9篇
  1988年   19篇
  1987年   13篇
  1986年   8篇
  1985年   8篇
  1983年   2篇
  1982年   8篇
  1981年   8篇
  1980年   8篇
  1978年   8篇
  1977年   28篇
  1976年   59篇
  1975年   1篇
  1954年   1篇
排序方式: 共有1044条查询结果,搜索用时 0 毫秒
131.
This report describes an acute right coronary artery dissection occurring during diagnostic cardiac catheterization. Following catheter manipulation in the vicinity of the aortic valve, the patient complained of mild chest discomfort and had transient electrocardiographic evidence of acute inferior wall myocardial infarction with runs of 2:1 atrioventricular block. Within 5 min, the EKG reverted to precatheterization appearance, and the patient was asymptomatic. Coronary angiography revealed a dissection of the proximal vessel without obstruction. The patient had no clinical sequelae while monitored in the intensive care unit. The patient underwent elective aortic and mitral valve replacement. The area of the dissection was directly visualized, and no abnormality was noted. We review the literature of spontaneous and iatrogenic coronary artery dissections with regard to pathology, diagnosis, and prognosis, and make recommendations for therapy.  相似文献   
132.
133.
134.
135.
136.
Empirical interatomic potential for Si-H interactions   总被引:1,自引:0,他引:1  
  相似文献   
137.
The paper presents the data available in the literature on computed tomographic angiography and the first experience with it to study thoracic vessels. It details the principles of spiral computed tomography and CT angiography. Practical aspects of their implementation, as well as basic concepts are outlined. It is concluded that CT angiography is promising in studying thoracic vessels in various abnormalities.  相似文献   
138.
The activity of metabolism changed in the cultures of Streptococcus diacetilactis, strain Bogdan, with aging. The number of viable cells decreased as well as the ability to evolve oxygen, to produce C-4 compounds, and to react to pH changes by liberating acids upon alkalifying or neutral products upon acidifying. After the culture had been grown during 72 hours, 2,3-butyleneglycol was found in the cultural broth, and the number of viable cells was low. As was revealed by electron microscopy, the cells were intact during 48 hours; they started to disintegrate by 72 hours. After 120 hours all cells were disintegrated. First, the cells produced no more mesosomes, became less electron dense; then the cell wall was decomposed and the contents of the cell poured through disruptions in the cytoplasmic membrane.  相似文献   
139.
Enterolobin, a 55-kDa cytolytic, inflammatory, and insecticidal protein isolated from seeds of the Brazilian tree Enterolobium contortisiliquum (Leguminosae-Mimosoideae) has been further purified and partially sequenced by using both manual and automated methods. A computational search of enterolobin partial amino acid sequence against the PIR database revealed possible sequence similarities with aerolysins, cytolytic proteins from Aeromonas species. An alignment of enterolobin partial sequence to the amino acid sequences of A. hydrophila and A. sobria aerolysins showed several similar regions with many residue identities. The seed protein enterolobin and the bacterial aerolysins may be homologous proteins despite the distant phylogenetic relationship.  相似文献   
140.
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