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   132篇
  免费   9篇
  国内免费   4篇
电工技术   10篇
综合类   2篇
化学工业   27篇
金属工艺   2篇
机械仪表   6篇
建筑科学   5篇
能源动力   3篇
轻工业   44篇
水利工程   1篇
无线电   5篇
一般工业技术   21篇
冶金工业   3篇
原子能技术   6篇
自动化技术   10篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   6篇
  2016年   5篇
  2015年   1篇
  2013年   24篇
  2012年   1篇
  2011年   2篇
  2010年   5篇
  2009年   8篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   6篇
  2004年   3篇
  2003年   1篇
  2002年   3篇
  2001年   2篇
  1999年   1篇
  1998年   2篇
  1997年   6篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   5篇
  1986年   1篇
  1985年   2篇
  1984年   4篇
  1983年   1篇
  1982年   4篇
  1981年   8篇
  1980年   3篇
  1978年   2篇
  1974年   1篇
  1973年   1篇
  1972年   2篇
  1971年   3篇
  1970年   1篇
排序方式: 共有145条查询结果,搜索用时 0 毫秒
31.
本文例举了目前智能建筑领域中的几种控制系统的应用,并根据这些应用阐述了采用开放式系统的重要性。  相似文献   
32.
Synthesis and Thermal Stability of Aluminum Titanate Solid Solutions   总被引:4,自引:0,他引:4  
Aluminum titanate solid solutions with empirical formulas of Al2Ti1-xZrxO5, Al6(2-x)(6+x)Si6x/(6+x)6x/(6+x)TiO5, and Al2(1-x)MgxTi1+xO5 were synthesized by reaction sintering and annealed at 900° to 1300°C in air to evaluate the thermal stability. Substitution of Al in Al2TiO5 by Si and 2Al by Mg and Ti ions to form solid solutions such as AI6(2-x)/(6+x)l-Si6x/(6+x)□6x/(6+x)TiO5, and Al2(1-x)MgxTi1+xO5 was effective in controlling the thermal decomposition, but substitution of Ti by Zr had little effect.  相似文献   
33.
Laser-induced breakdown spectroscopy(LIBS) was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded. As an example of Si contamination, silicone oil was employed and sprayed onto substrates with a controlled surface concentration. LIBS measurements employing nanosecond UV pulses(λ?=?266 nm) and an off-axis emission collection system with different detecting heights were performed. Because surface contaminants are involved in the plasma formed by laser ablation of the substrates, the relative contribution of the surface contaminants and the substrates to the plasma emission could be changed depending on the conditions for plasma formation. The limit of detection(LOD) was evaluated under several detecting conditions for investigating the factors that affected the LOD. A significant factor was the standard deviation values of signal intensities obtained for the clean substrates. This value varied depending on the measurement conditions.For the Al alloy(A6061), the smallest LOD obtained was 0.529 μg?·?cm~(-2). Furthermore, an improved LOD(0.299 μg?·?cm~(-2)) was obtained for the Al alloy with a lower Si content.  相似文献   
34.
The objective of the present study is to compare the protein cross‐linking reaction in Alaska pollock surimi that is catalyzed by a commercially available microbial transglutaminase and by endogenous Alaska pollock transglutaminase. The endogenous transglutaminase was inhibited by EGTA and activated by CaCl2 The microbial transglutaminase was added to the salted surimi with and without EGTA and CaCl2. These surimi pastes were incubated at 25C up to 24 h followed by cooking at 90C. The resultant gels were fractionated into soluble and insoluble (aggregate) fractions by SDS‐urea extraction. Compositional analysis revealed that the aggregate consisted predominantly of cross‐linked myosin heavy chain. The distribution of ?‐(γ‐glutamyl)lysine isopeptide in the soluble and aggregate fractions andpeptide mapping analyses of the aggregate fraction demonstrate that the formation of isopeptide cross‐links in Alaska pollock surimi proteins during suwari process differs when catalyzed by the microbial transglutaminase and endogenous transglutaminase.  相似文献   
35.
Recently, with the expansion of communication network areas, the number of radio communication stations built in the neighborhood of customer houses has increased. If lightning strikes a communication radio tower, part of the lightning current flows into the distribution line and into customer houses. This may cause the failure of distribution lines or customer equipment. To protect distribution lines and customer equipment from lightning faults, it is necessary to analyze the surge phenomena in distribution lines and customer equipment and take appropriate protection measures. In this study, we examined the effect of lightning protection measures for distribution lines and customer equipment against lightning strikes to a communication tower. First, using an actual‐scale test distribution line, we measured the lightning current flowing into distribution lines and customer equipment. Second, we quantitatively examined the effect of lightning protection measures by lighting surge analysis while changing each parameter. From the experimental and analytical results, we show that the proposed protection measures can reduce the lightning current flowing into distribution lines and customer equipment.  相似文献   
36.
Hydrated alkaline earth cyclo-octaphosphates were made by adding an aqueous solution of alkaline earth chlorides into an aqueous solution of sodium cyclo-octaphosphate. Thermal properties of the compounds were studied by TG-DTA analysis. The water of crystallization was removed below 200°C. The cyclo-octaphosphates decomposed to produce many phosphate species up to about 500°C, and they finally reorganized to metaphosphates. The overall thermal reaction of alkaline earth cyclo-octaphosphates can be written by the equation. M4(PO3)8 · nH2O 4M(PO3)2 + nH2O  相似文献   
37.
The auto-resonant peniotron has been theoretically expected to have a very high conversion efficiency (nearly 100%) for an ideal electron beam with an appropriate value for the velocity ratio interacting in a suitable circuit with an electromagnetic wave whose phase velocity is equal to the velocity of light in free space. This paper presents experimental results showing more than 70% electronic efficiency obtained from an auto-resonant peniotron oscillator with a magnetron type cavity.  相似文献   
38.
39.
Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
40.
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