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   2402篇
  免费   0篇
电工技术   2篇
化学工业   7篇
建筑科学   2篇
轻工业   2篇
石油天然气   2篇
无线电   3篇
一般工业技术   6篇
冶金工业   2377篇
自动化技术   1篇
  2021年   1篇
  2019年   1篇
  2018年   1篇
  2012年   1篇
  2009年   3篇
  2008年   1篇
  2006年   2篇
  2003年   3篇
  2002年   2篇
  2001年   2篇
  2000年   2篇
  1999年   75篇
  1998年   695篇
  1997年   405篇
  1996年   249篇
  1995年   144篇
  1994年   146篇
  1993年   149篇
  1992年   31篇
  1991年   32篇
  1990年   40篇
  1989年   66篇
  1988年   40篇
  1987年   36篇
  1986年   26篇
  1985年   24篇
  1983年   3篇
  1982年   11篇
  1981年   13篇
  1980年   18篇
  1979年   2篇
  1978年   7篇
  1977年   55篇
  1976年   113篇
  1975年   1篇
  1955年   2篇
排序方式: 共有2402条查询结果,搜索用时 15 毫秒
91.
The neuropeptide galanin (GAL) has a widespread distribution throughout the human cortex. The entorhinal cortex (ENT) plays a crucial role in the transfer of cortico-cortical information related to memory and displays severe degeneration in Alzheimer's disease (AD). However, very little is known about the pharmacology of the GAL receptor (GALR) in normal human ENT. Therefore, we pharmacologically visualized their distribution and characterized GALRs using in vitro receptor autoradiography and radioligand binding assays. Autoradiograms revealed intense GALR labeling, mainly in the substantia innominata, hypothalamus, the bed nucleus of the stria terminalis and within layers 2 and 4 of the ENT. Kinetic experiments showed that saturation of GALR sites by [125I]GAL (human) (hGAL) occurred within 2 h and that this binding readily reversed in the presence of a GTP analog, but not in the presence of excess unlabeled hGAL. Analysis of [125I]hGAL binding data from saturation experiments gave KD values of 98.6+/-21.6 pM, Bmax values of 52.9+/-32.4 fmol/mg protein and identified a high and low affinity state of the GALR. The presence of 5'-guanylylimidodiphosphate (GppNHp) or NaCl reduced the agonist labeling of hGALR in ENT membranes.  相似文献   
92.
93.
94.
95.
96.
Factors contributing to subsidence were analyzed by radiographic evaluation and mechanical testing of 36 canine cadaver femora during and after insertion of an uncemented porous-coated femoral stem and by radiographic evaluation of 35 canine total hip arthroplasties. Mean percentage of canal fill in immediate postoperative radiographs, and percentage of canal fill at midimplant and distal implant locations, were accurate predictors of subsidence. Force required to implant the femoral stem was strongly correlated with force required for implant subsidence. Femoral morphology and percentage of canal fill at the middle and distal sites were accurate predictors of subsidence. Implants in femora with a stovepipe morphology (canal flare index less than or equal to 1.8) were six times more likely to subside than implants in femora that had a normal appearance (canal flare index 1.8 to 2.5), and 72 times more likely to subside than implants in champagne-fluted femora (canal flare index greater than or equal to 2.5). Femora with more than 85% mean, middle, or distal canal fill were less likely to subside.  相似文献   
97.
98.
Anal warts in a population of gay men in New York City   总被引:3,自引:0,他引:3  
  相似文献   
99.
The St. Agnes Community Health Centre was established in October 1974, in the rapidly growing area of Tea Tree Gully, South Australia. It was built to provide additional facilities to an already existing comprehensive medical centre. The embryo centre is described during the first year of operation through the eyes of the health team.  相似文献   
100.
An analysis of the results of a study of a group of post-infarction patients who had received group instruction concerning the nature of myocardial infarction, compared with patients not so instructed, is presented. Contrary to expectation, anxiety levels as measured by the Catel IPTA Anxiety Scale were significantly higher in patients who experienced group education. Regardless of this finding, patients were subjectively appreciative of education.  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