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   1814篇
  免费   0篇
化学工业   9篇
机械仪表   1篇
建筑科学   7篇
能源动力   1篇
轻工业   5篇
石油天然气   17篇
无线电   1篇
一般工业技术   2篇
冶金工业   1745篇
自动化技术   26篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2015年   1篇
  2014年   7篇
  2013年   4篇
  2012年   3篇
  2011年   1篇
  2010年   5篇
  2009年   5篇
  2008年   1篇
  2007年   3篇
  2006年   1篇
  2005年   5篇
  2004年   2篇
  2003年   16篇
  2002年   6篇
  2001年   4篇
  2000年   3篇
  1999年   54篇
  1998年   522篇
  1997年   291篇
  1996年   226篇
  1995年   110篇
  1994年   98篇
  1993年   104篇
  1992年   11篇
  1991年   30篇
  1990年   32篇
  1989年   23篇
  1988年   37篇
  1987年   22篇
  1986年   22篇
  1985年   13篇
  1983年   3篇
  1982年   10篇
  1981年   12篇
  1980年   11篇
  1978年   3篇
  1977年   36篇
  1976年   71篇
  1966年   1篇
排序方式: 共有1814条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
Mortality rates among White Leghorn-Rhode Island Red pure-line and reciprocal cross adult female progeny were recorded for 8 years. The mortality rate among progeny of White Leghorn males exceeded that of the progeny of Rhode Island Red males in both pure-line and crossbreds. White Leghorn X Rhode Island Red crossbred progeny had the highest mortality rate. In a second phase of the study, a comparison was made between mortality rates of male and female progeny of White Leghorn-Rhode Island Red reciprocal crosses. Rate of loss was significantly lower in males than in females but did not differ between crosses. These results support a conclusion that sex linkage is a major factor in differential mortality rates between progeny of White Longhorn-heavy breed reciprocal crosses.  相似文献   
95.
96.
Biomechanical analysis using nondestructive and destructive investigative methods was performed to evaluate the mechanisms of cervical compression injuries. These injuries produce two basic modes of failure: 1) anterior dislocation; and 2) rupture of the anterior ligamentous complex of the vertebral body. Distribution of these two failure patterns was determined by the initial cervical spine position; translational alignment did not have a significant effect. Different results were observed between spines positioned in flexion and extension, indicating that the most important factor determining the mode of failure was rotational alignment in the sagittal plane.  相似文献   
97.
The increased incidence of drowsiness in hypoalbuminemic patients administered diazepam and more rapid clearance of tolbutamide in cirrhotics may be due to changes in plasma protein binding. The binding of diazepam and tolbutamide was studied by equilibrium dialysis at 37degreesC over a total drug concentration range of 1 to 10 mug/ml and 50 to 300 mug/ml, respectively, in plasma from 21 normal and 14 alcoholic subjects. At 1 mug/ml, diazepam plasma protein binding (+/- S.D.) was 98.5+/-0.4 per cent in normals and 97.8+/-1.2 per cent in alcoholics; at 100 mug/ml, tolbutamide binding was 97.8+/-0.3 per cent in normals and 95.1+/-4.2 per cent in alcoholics. For both agents at all concentrations, the binding to plasma from alcoholics was significantly decreased (P less than 0.01-less than 0.02). The extent of binding of both drugs was dependent on the albumin concentration. These findings suggest that important changes in pharmacologic effect, distribution, and clearance of diazepam and tolbutamide can be anticipated in alcoholics with hypoalbuminemia.  相似文献   
98.
99.
100.
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