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   1368篇
  免费   3篇
  国内免费   2篇
化学工业   11篇
金属工艺   1篇
机械仪表   1篇
建筑科学   4篇
矿业工程   1篇
能源动力   9篇
轻工业   10篇
石油天然气   1篇
无线电   3篇
一般工业技术   15篇
冶金工业   1314篇
原子能技术   1篇
自动化技术   2篇
  2021年   1篇
  2020年   1篇
  2019年   3篇
  2018年   4篇
  2017年   1篇
  2016年   1篇
  2015年   2篇
  2013年   4篇
  2011年   1篇
  2008年   1篇
  2007年   1篇
  2005年   2篇
  2004年   3篇
  2003年   3篇
  2002年   5篇
  1999年   41篇
  1998年   392篇
  1997年   243篇
  1996年   146篇
  1995年   81篇
  1994年   68篇
  1993年   80篇
  1992年   9篇
  1991年   14篇
  1990年   8篇
  1989年   13篇
  1988年   18篇
  1987年   15篇
  1986年   13篇
  1985年   11篇
  1984年   3篇
  1983年   6篇
  1982年   8篇
  1981年   16篇
  1980年   16篇
  1978年   5篇
  1977年   47篇
  1976年   79篇
  1975年   4篇
  1974年   1篇
  1955年   3篇
排序方式: 共有1373条查询结果,搜索用时 468 毫秒
51.
52.
53.
54.
OBJECTIVE: To assess the outcomes of changes in mental health policy introduced in Italy in 1978. METHODS: Data on psychiatric services, before and after the policy change, are presented. Effects of change are evaluated through indicators related to four issues: transfer of care, criminalisation of the mentally ill, suicides, and homelessness. RESULTS: Admissions of new patients to mental hospitals have been stopped and the size of the mental hospital population is now very low (26 per 100,000 population). Psychiatric care has been shifted to community services including general hospital psychiatric units. There has been an overall reduction of psychiatric hospitalisation. However, the provision of residential facilities is inadequate and community services are unevenly distributed across the country. Few negative effects of changing patterns of care have been reported, although the low quality of data limits the validity of such a conclusion. Outcome of care in areas where the full range of community services is available has been rated as satisfactory. CONCLUSIONS: Although care of the mentally ill has been shifted to community services, we lack hard data on the social and clinical outcome of community care at the nation-wide level. Long-term monitoring and evaluation of community services is a high priority in Italy.  相似文献   
55.
56.
57.
58.
Two noninvasive tests for assessing pancreatic exocrine function, the cholesteryl-[14C]octanoate breath test and the HPLCN-benzoyl-tyrosyl-p-aminobenzoic acid/p-aminosalicylic acid (NBT-PABA/PAS) test, were simultaneously performed in nine patients with pancreatic exocrine insufficiency due to chronic pancreatitis and in nine healthy volunteers. 14CO2 output in breath and plasma PABA concentration rose slowly in patients but increased rapidly in healthy subjects. The measurement time giving the best discrimination between both groups was 120 min for the cholesteryl-[14C]octanoate breath test and 90 min for the plasma PABA test. At these points, both single-sample tests had essentially identical diagnostic sensitivity. The diagnostic sensitivities of the two single-sample tests were equal to that of the cumulative 6-h urinary PABA recovery and the cumulative 6-h urinary PABA/PAS ratio. We conclude that, for both the cholesteryl-[14C]octanoate breath test and the plasma PABA test, a single test sample is sufficient for rapid detection of impaired exocrine pancreatic function.  相似文献   
59.
The effect of two different methods of reconstruction of flatfoot deformity and the role of the posterior tibial tendon on the contact characteristics of the hindfoot joints were quantified using pressure-sensitive film. Each of 10 cadaver feet was loaded quasi-statically by an axial compressive force to simulate varying loads. First, a specimen was tested intact, then it was tested after sectioning the spring ligament and loading the specimen cyclically to create one type of flatfoot deformity. It was then tested again after reconstructing the deformity. Reconstructions used were the Dillwyn-Evans procedure (bone graft in osteotomy of the calcaneus) or the calcaneocuboid distraction arthrodesis (CCDA). We found that surgically produced flatfoot deformity altered mainly the talonavicular joint, by decreasing its contact area. The Dillwyn-Evans method had less effect on the talonavicular joint (altering 2 of 6 measured parameters) than the CCDA (3 of 6) and more effect on the anteriomedial facet (altering 3 of 6 parameters) than the CCDA (1 of 6). The Dillwyn-Evans method had more effect on the posterior facet (altering 2 of 6 measured parameters) than the CCDA (1 of 6). Function of the posterior tibial tendon had no effect on contact characteristics of the hindfoot joints after either type of reconstruction. These findings are based on measurements using a quasi-statically-loaded foot model at three selected positions, and results may be different with dynamic loading.  相似文献   
60.
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