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   630篇
  免费   2篇
  国内免费   4篇
电工技术   6篇
综合类   2篇
化学工业   17篇
金属工艺   7篇
机械仪表   3篇
建筑科学   2篇
矿业工程   1篇
轻工业   6篇
水利工程   10篇
石油天然气   17篇
无线电   3篇
一般工业技术   24篇
冶金工业   480篇
原子能技术   44篇
自动化技术   14篇
  2020年   2篇
  2019年   2篇
  2017年   3篇
  2016年   4篇
  2015年   5篇
  2014年   3篇
  2013年   4篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   6篇
  2008年   7篇
  2007年   7篇
  2006年   5篇
  2005年   10篇
  2004年   4篇
  2003年   2篇
  2000年   6篇
  1999年   2篇
  1998年   116篇
  1997年   74篇
  1996年   64篇
  1995年   31篇
  1994年   22篇
  1993年   27篇
  1992年   4篇
  1991年   4篇
  1990年   3篇
  1989年   4篇
  1988年   7篇
  1987年   5篇
  1986年   8篇
  1985年   7篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   6篇
  1980年   10篇
  1979年   7篇
  1978年   5篇
  1977年   33篇
  1976年   65篇
  1975年   9篇
  1974年   10篇
  1972年   4篇
  1970年   3篇
  1969年   2篇
  1965年   2篇
  1962年   3篇
  1955年   2篇
排序方式: 共有636条查询结果,搜索用时 15 毫秒
631.
632.
Guanylspecific RNAse C2 has been studied thermodynamically using a microcalorimetry technique. It is shown that at ph varying from 5,0 to 8,0 the RNAse C2 solution in a cacodylate buffer contains about 30% of monomeric and about 70% of dimeric forms of protein, each of them melting as a single cooperative system. Moreover, studies of the influence of phosphate ions have shown that they stabilize the system by 3-4 degrees and transform it into a monomeric form.  相似文献   
633.
The subcellular distribution and segmental variations in location of gp330, a scavenger receptor for filtered proteins in renal proximal tubules, was analyzed. Kidney tissue from rats (4 different strains), rabbits and humans were analyzed by light- and electron microscope immunocytochemistry, using cryosections or Lowicryl sections from cryosubstituted tissue. Gp330 was located mainly in apical coated pits, small and large endocytic vacuoles and in dense apical tubules in the proximal tubule cells. The labeling density was markedly higher in segments 1 and 2 as compared to segment 3 of the proximal tubule. In addition to the location in the early part of the endocytic pathway, gp330 was also present in lysosomes, especially in segments 1 and 2. The lysosomal labeling was not restricted to the membrane, but was also seen in the matrix. Localization of gp330 in lysosomes was confirmed on sections from purified lysosomal fractions from rat renal cortex. The brush border localization of gp330 in proximal tubules exhibited a characteristic segmental variation. In the initial part of segment 1, there was virtually no brush border labeling. In the remaining part of segment 1 and in segment 2, there was a distinct but sometimes patchy labeling of the brush border. In segment 3, groups of microvilli of approximately 10 as seen in sections were intensively labeled from bottom to tip and there were often more than one of these groups on a single cell, the remaining microvilli were unlabeled. No differences in the cellular and subcellular localization of gp330 were observed between species or rat strains. In conclusion, the present study demonstrates that in addition to its location in the early endocytic and recycling pathway, gp330 is also present in microvilli and the protein and degradation products thereof is present in lysosomes, consistent with its role as a protein scavenger receptor.  相似文献   
634.
This study investigated the relation of population size, amount of personal space, and population density to the incidence of disruptive behavior over a 3-year period in a correctional institution for male youthful offenders. Population size was significantly correlated with the number but not the rate of disciplinary violations. The total amount of personal space and the index of population density were significantly correlated with both the number and the rate of violations. A post hoc analysis showed that the incidence of uncomfortably hot days had no relation to disruptive behavior. These results are contrasted with laboratory data on human crowding reporting no relation between population density and behavior pathology. It is suggested that the chronic high density explored in the present field study differs from temporarily crowded conditions produced in laboratory research on human crowding.  相似文献   
635.
636.
Conclusions During the journal's 50-yr existence, it has shed light on a broad circle of problems associated with water management. As it developed and new problems were put forth by construction practice, the subject matter of papers was expanded, and many questions received a more profound and comprehensive coverage.In the modern stage of the development of our country's water-conservation construction, the journal should, together with traditional problems, focus more attention on questions of territorial flow redistribution, measures for protecting water resources from depletion and pollution, and measures for increasing the effectiveness of both reservoirs and natural water bodies due to their engineering layout; in all cases, the ecological and economic aspects of problems associated with water management should receive broader coverage.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 36–39, November, 1981.  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