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   1103篇
  免费   56篇
  国内免费   1篇
电工技术   27篇
化学工业   244篇
金属工艺   31篇
机械仪表   40篇
建筑科学   38篇
矿业工程   25篇
能源动力   23篇
轻工业   45篇
水利工程   12篇
石油天然气   24篇
无线电   69篇
一般工业技术   243篇
冶金工业   143篇
原子能技术   61篇
自动化技术   135篇
  2023年   10篇
  2022年   26篇
  2021年   52篇
  2020年   28篇
  2019年   24篇
  2018年   40篇
  2017年   41篇
  2016年   47篇
  2015年   32篇
  2014年   49篇
  2013年   55篇
  2012年   50篇
  2011年   54篇
  2010年   41篇
  2009年   55篇
  2008年   47篇
  2007年   50篇
  2006年   27篇
  2005年   37篇
  2004年   26篇
  2003年   34篇
  2002年   24篇
  2001年   14篇
  2000年   13篇
  1999年   9篇
  1998年   19篇
  1997年   7篇
  1996年   13篇
  1994年   9篇
  1993年   14篇
  1992年   12篇
  1991年   14篇
  1990年   9篇
  1988年   6篇
  1987年   6篇
  1986年   8篇
  1985年   12篇
  1983年   8篇
  1980年   9篇
  1979年   11篇
  1977年   6篇
  1976年   8篇
  1975年   5篇
  1974年   8篇
  1973年   9篇
  1972年   9篇
  1970年   7篇
  1969年   5篇
  1968年   7篇
  1967年   5篇
排序方式: 共有1160条查询结果,搜索用时 15 毫秒
51.
Plasma excited by a longitudinal pulse-periodic discharge in a mixed flow of a buffer gas (Ar), oxidizer (H2O), and aluminum dust is studied. The salient features of its kinetics are the atomic and molecular electronic channels of Al atom transformation, which were not taken into account earlier. They accelerate not only the oxidation process but also aluminum vaporization because the excitation and ionization energies are finally released on the surface of aluminum particles. This work is devoted to experimental and theoretical analysis of these channels.  相似文献   
52.
Relations for sampling functions in nonuniform sampling of a trigonometric polynomial and its derivatives are obtained.  相似文献   
53.
Photo-stimulated interdiffusion in a-Se/As2S3 amorphous chalcogenide nano-multilayers (ANML) is known as a useful method for amplitude-phase optical relief formation besides the known amorphous–amorphous or amorphous–crystalline photo-induced structural transformations (PST) in homogeneous chalcogenide layers, but it has a relatively narrow sensitivity spectral range and small amplitude modulation. Experimental evidences of improvement of optical recording processes were obtained in Te-, Bi-, Sb-containing nano-layered structures based on As2S3 matrix. The influence of nano-structuring and combination of components on the sensitivity, type of the recorded relief is discussed.  相似文献   
54.
The problem of active fault‐tolerant control with reconfiguration mechanism for uncertain linear systems with external disturbances is addressed applying the supervisory control approach. A key feature of the proposed approach is establishment of a set of conditions providing mutual performance in the sense of taking into account the interaction of the fault detection, isolation, and accommodation subsystems in order to achieve global fault‐tolerance performance with guaranteed global stability. The efficiency of the approach is demonstrated in an example of computer simulation for a flight system benchmark. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
55.
The paper discusses the data of four-point bending strength for various rock types. Different nonlocal strength criteria are applied to the tensile strength assessments based on measuring the bending strength. The tensile strength calculated using a bar bending model under plastic deformation turns out to be the closest in value to the experimental strength.  相似文献   
56.
57.
The article sheds new light on sensory elements in legal cases concerning misleading food labelling. It presents the findings of a qualitative review of 821 cases on misleading food labelling registered in 2002–2007 by the Danish food authorities. The cases show that sensory tends to be backgrounded by other arguments more easily verbalized. A taxonomy of the sensory dimensions of the cases is set up and different sensory aspects are analyzed in order to establish to what the extent and how sensory variables can be integrated into experimental setups for testing the misleading potential of food naming and labelling solutions with a view to promoting “fair speak” principles for in-store food-to-consumer communication. The study is part of the cross-disciplinary research project “Spin or fair speak – when foods talk” which aims at providing new knowledge, tools, and experimental evidence for self-regulation, public control, and innovation in food naming and labelling.  相似文献   
58.
In rolling shop 1 at OAO ChMK, reconstruction of the pass-through furnaces associated with the 780, 300-2, and 240 bar mills, together with the introduction of automated fuel-consumption meters and other resource-conserving measures, has reduced fuel consumption by 12%, with some decrease in output. Information is presented regarding the structural changes associated with the use of thicker billet. Furnaces of the new design are promising in terms of improvements in performance and energy conservation.  相似文献   
59.
60.
Efimov OM  Glebov LB  Andre HP 《Applied optics》2002,41(10):1864-1871
A liquid-cell shearing interferometer was developed to measure refractive-index variations (delta n) in transparent materials. The cell was filled with a liquid having a matched refractive index. The achieved resolution was better than 1/1000 of a fringe shift and resulted in a delta n measurement sensitivity down to 10(-7) for 1-mm-thick samples. A refractive-index increment in photothermorefractive glass of up to 5 x 10(-6) was observed after UV exposure at 325 nm. A refractive-index decrement of up to 1 x 10(-3) was observed after thermal development of the exposed sample. It was proved that photothermorefractive glass obeys the reciprocity law; i.e., delta n depends on the UV dosage but does not depend on the irradiance.  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