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   564篇
  免费   1篇
电工技术   2篇
化学工业   36篇
金属工艺   12篇
机械仪表   5篇
建筑科学   3篇
矿业工程   9篇
轻工业   6篇
水利工程   3篇
石油天然气   20篇
无线电   6篇
一般工业技术   85篇
冶金工业   331篇
原子能技术   42篇
自动化技术   5篇
  2013年   3篇
  2010年   2篇
  2008年   2篇
  2005年   2篇
  2004年   3篇
  2003年   11篇
  2002年   5篇
  2001年   2篇
  1999年   6篇
  1998年   67篇
  1997年   43篇
  1996年   45篇
  1995年   18篇
  1994年   22篇
  1993年   19篇
  1992年   3篇
  1991年   13篇
  1990年   6篇
  1989年   8篇
  1988年   13篇
  1987年   10篇
  1986年   11篇
  1985年   12篇
  1984年   7篇
  1983年   7篇
  1982年   5篇
  1981年   12篇
  1980年   15篇
  1979年   7篇
  1978年   9篇
  1977年   21篇
  1976年   40篇
  1975年   10篇
  1974年   7篇
  1973年   13篇
  1972年   12篇
  1971年   7篇
  1970年   9篇
  1969年   8篇
  1968年   9篇
  1967年   6篇
  1966年   5篇
  1965年   8篇
  1964年   3篇
  1962年   1篇
  1961年   3篇
  1960年   3篇
  1959年   4篇
  1958年   3篇
  1957年   1篇
排序方式: 共有565条查询结果,搜索用时 15 毫秒
1.
A probabilistic image model is proposed. According to the model, the noise of the boundaries has the principal effect on the precision with which the dimensions of optical monitoring objects are measured. Results of theoretical and experimental investigations of measurement precision are presented. An approach to the determination of monitoring reliability and the selection of the resolution of a machine vision system based on structural requirements is formulated.  相似文献   
2.
The article presents the results of experimental investigations of critical (limit) heat fluxes upon evaporation on porous coatings, and it substantiates the physical model of the process.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 4, pp. 607–614, October, 1985.  相似文献   
3.
4.
Experiments were performed for comparative assessment of the effect of ionizing radiation on the service characteristics of 30% TBP solutions in various diluents: hexachlorobutadiene (HCBD), mixtures of n-paraffins (RED diluent), and fraction of naphthenic hydrocarbons (RZh diluent). The following main parameters were chosen for comparative assessment of the quality of irradiated extractant solutions: composition and behavior of diluent radiolysis products, effect of diluents on the TBP radiolysis, and aggregative stability of emulsions in the main operations of the extraction cycle. The service life of the extraction mixtures was estimated from variation of the above parameters with the irradiation dose. Principles for choosing solvents with increased service life under irradiation were substantiated.  相似文献   
5.
6.
7.
BACKGROUND: The matrix metalloproteinases (MMPs) MMP2 and MMP9 play a significant role in epidermal detachment, inflammation and re-epithelialization. We have evaluated their activity in toxic epidermal necrolysis (TEN). DESIGN: The level and pattern of activity of MMP2 and MMP9 were investigated by measuring the degradation of 3H-labelled gelatin and by zymography in blister fluid from six TEN patients and compared the results with three other blistering conditions: bullous pemphigoid (n = 6), second-degree burn (n = 13) or suction blister (n = 3). RESULTS: A higher amount of MMP2 was found in TEN blister fluid with the constant presence of a significantly larger proportion of the activated forms of MMP2, a particular feature of TEN, than the other blistering diseases studied. CONCLUSION: This study emphasizes the potential role of MMP2 in the specific inflammatory reaction and reparation process in TEN skin.  相似文献   
8.
A simple method has been developed for continuous monitoring of metabolic activity of an isolated, perfused rat heart by O2/CO2 respirometer. Since respirometer provides vital data on oxygen consumption and carbon dioxide production of a preserved organ on a continuous basis over a long period of time, it will be possible to use this method to monitor viability of not only isolated heart but also any given donor organ under preservation.  相似文献   
9.
In sheet stamping, friction appears between the tool and the deformed preform. It is of interest to evaluate the difference in the friction coefficient in stamping by tools subjected to different kinds of heat treatment and chemical heat treatment.  相似文献   
10.
Release of Ca2+ from mitochondria into cytosol in intact thymocytes was studied using the fluorescent dye Fluo-3. It was shown that the release of Ca2+ induced by the dithiol cross-linking agent phenylarsine oxide or by uncoupler was strongly inhibited by cyclosporin A, a specific inhibitor of the permeability transition pore (PTP) in mitochondria. Oxidative stress sensitized the pore so even partial uncoupling caused rapid cyclosporin A-sensitive release of Ca2+. The experiments on digitonin-permeabilized cells confirmed that uncoupling induced opening of the PTP, which forms the major pathway for rapid release of Ca2+ from thymocyte mitochondria.  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