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   1059篇
  免费   5篇
  国内免费   1篇
电工技术   18篇
化学工业   146篇
金属工艺   118篇
机械仪表   28篇
建筑科学   3篇
矿业工程   10篇
能源动力   5篇
轻工业   3篇
水利工程   8篇
石油天然气   36篇
无线电   160篇
一般工业技术   280篇
冶金工业   140篇
原子能技术   66篇
自动化技术   44篇
  2021年   13篇
  2020年   15篇
  2019年   21篇
  2018年   35篇
  2017年   28篇
  2016年   33篇
  2015年   11篇
  2014年   32篇
  2013年   33篇
  2012年   35篇
  2011年   35篇
  2010年   30篇
  2009年   42篇
  2008年   23篇
  2007年   41篇
  2006年   35篇
  2005年   25篇
  2004年   24篇
  2003年   21篇
  2002年   23篇
  2001年   14篇
  2000年   24篇
  1999年   27篇
  1998年   22篇
  1997年   13篇
  1996年   10篇
  1995年   11篇
  1994年   10篇
  1993年   10篇
  1992年   13篇
  1991年   13篇
  1990年   13篇
  1989年   12篇
  1987年   17篇
  1986年   18篇
  1985年   19篇
  1984年   14篇
  1982年   13篇
  1981年   12篇
  1979年   9篇
  1978年   13篇
  1977年   12篇
  1976年   16篇
  1975年   13篇
  1974年   12篇
  1973年   11篇
  1972年   22篇
  1971年   18篇
  1970年   12篇
  1969年   16篇
排序方式: 共有1065条查询结果,搜索用时 15 毫秒
1.
The Chelyabinsk Metallurgical Combine has periodically used Kachkanar agglomerate to make conversion pig iron since 1972. Use of this material reached a peak in 1998, when it comprised an average of 27.1% of the charge. In some months, the amount of this material charged into the furnace reached highs of 45.6 and 74.1% on certain furnaces. The coolers on the iron notches of furnaces 4 and 5 burned during that year, the quality of the smelting products and the condition of the ladles rapidly deteriorated, and the smelting rate declined. No Kachkanar agglomerate was used in 2000–2001, but it was again added to the charge in February 2002. The amount used was smaller than previously, averaging 10.7% for the shop as a whole. It was determined that using a charge with 15% Kachkanar agglomerate has both positive and negative consequences. N. N. Gorshkov, A. V. Denisov, and V. Kh. Barinov also participated in this study. __________ Translated from Metallurg, No. 3, pp. 43–45, March, 2006.  相似文献   
2.
Increasing attention at oil refineries is being focused on solving environmental problems caused by stiffening of the requirements for emissions of harmful substances into air and water. Advanced technologies that reduce the effect of industrial enterprises on the environment to the minimum are becoming increasingly in demand. Treatment of process wastewaters to remove hydrogen sulfide and ammonia is one such problem of the modern refinery with cat crackers. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 52–55, May–June, 2006.  相似文献   
3.
Changes in the activity of acid phosphatase (AP) and its isoenzymes (tartrate-insensitive AP and formalin-insensitive AP) were investigated in patients with food poisoning in the course of the disease. The activity of AP and its isoenzymes in the serum started to grow in early convalescence and reached maximum in late convalescence. Total activity of AP in food toxic infections consists primarily of the activity of its platelet fraction. AP activity may serve as an additional criterion to predict vascular platelet involvement of hemostasis.  相似文献   
4.
Catalytic oxidation of sulfide ions over nickel hydroxides   总被引:2,自引:0,他引:2  
The catalytic sulfide ion oxidation by oxygen to elemental sulfur over β-Ni(OH)2 and LiNiO2 has been studied. As a result of experimental investigation performed, a reaction mechanism is suggested which involves heterogeneous and homogeneous processes. Dioxygen activation in the heterogeneous process proceeds via a redox Ni2+ ↔ Ni3+ transition and participation of OH groups. The active HO2 species thus formed carries on the reaction in homogeneous phase. Nickel hydroxides are promising catalysts for practical application.  相似文献   
5.
The catalytic activity of a wide range of transition metal oxides in oxidation of sulphide ions by air in aqueous medium was studied. Some specific features of the reaction mechanism on some of the studied oxides were considered. The transition metal oxides are promising catalysts for practical application. Some of these oxides will allow the preparation of catalysts possessing activity comparable to that of the cobalt phthalocyanine based catalysts, popular in industrial practice.  相似文献   
6.
7.
8.
A new superfluid specific additive integral of motion is found. This facilitates investigation of the general thermodynamic equilibrium conditions of a superfluid. The analysis is performed in an extended space of thermodynamic variables containing (along with the usual thermodynamic coordinates such as pressure and temperature) superfluid velocity and momentum density. The equilibrium stability conditions lead to thermodynamic inequalities which replace the Landau superfluidity criterion at finite temperatures.  相似文献   
9.
10.
Results are offered from a study of heat liberation in boiling of liquid helium upon a heated wall under impulsive thermal action conditions.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 3, pp. 373–376, September, 1987.  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