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   1808篇
  免费   48篇
  国内免费   4篇
电工技术   116篇
综合类   3篇
化学工业   466篇
金属工艺   44篇
机械仪表   37篇
建筑科学   33篇
矿业工程   1篇
能源动力   136篇
轻工业   123篇
水利工程   2篇
石油天然气   1篇
无线电   139篇
一般工业技术   303篇
冶金工业   268篇
原子能技术   71篇
自动化技术   117篇
  2023年   12篇
  2022年   27篇
  2021年   38篇
  2020年   23篇
  2019年   22篇
  2018年   29篇
  2017年   22篇
  2016年   44篇
  2015年   25篇
  2014年   56篇
  2013年   98篇
  2012年   75篇
  2011年   97篇
  2010年   70篇
  2009年   69篇
  2008年   83篇
  2007年   76篇
  2006年   77篇
  2005年   53篇
  2004年   54篇
  2003年   55篇
  2002年   38篇
  2001年   40篇
  2000年   33篇
  1999年   44篇
  1998年   100篇
  1997年   83篇
  1996年   47篇
  1995年   35篇
  1994年   41篇
  1993年   35篇
  1992年   14篇
  1991年   22篇
  1990年   13篇
  1989年   17篇
  1988年   11篇
  1987年   17篇
  1986年   14篇
  1985年   8篇
  1984年   14篇
  1983年   8篇
  1982年   11篇
  1981年   14篇
  1980年   11篇
  1979年   8篇
  1978年   10篇
  1977年   11篇
  1976年   14篇
  1973年   6篇
  1970年   7篇
排序方式: 共有1860条查询结果,搜索用时 15 毫秒
51.
This paper proposes a multi-agent system that carries out cooperative work. To achieve this, we use Fuzzy Associative Memory Organizing Unit Systems (FAMOUS) and Conceptual Fuzzy Sets (CFS). By using these proposed methods, each agent robot can decide its own behaviour to suit the situation in its environment. We apply this system to an Intelligent Transportation System (ITS) and do simulations.  相似文献   
52.
NO reduction experiment was performed by injecting ammonia radicals, which were externally generated by flowing the NH3 gas diluted with Ar gas through a dielectric barrier discharge with a one-cycle sinusoidal-wave power source. The discharge was intermittently formed between coaxial cylindrical electrodes with a space of 1.5 mm at an applied peak-to-peak voltage of 3-25 kV. The generated radicals were injected into simulation gas (NO/O2/N2). The simulation gas contained 0-5.6% O2, and the effect of O2 on NOx removal was discussed. The minimum reaction temperature for NO reduction was low when simulation gas contained O2. High O2 concentration (O2=5.6%) in simulation gas, high repetition rate to NH3, and high applied power to NH3 decreased NO removal efficiency.  相似文献   
53.
Lesion studies have shown that the avian hippocampus plays a crucial role in homing pigeon (Columba livia) navigation. Using the expression of the immediate early gene protein ZENK in intact pigeons, the authors found regional variation in hippocampal activation as a consequence of homing and, necessarily, the behavior and internal states that accompany it. Specifically, pigeons that homed displayed a significant increase in the number of ZENK-labeled cells in the lateral hippocampal formation compared with pigeons that did not home, whereas no difference was seen in the medial hippocampus. Significant changes in ZENK expression were also found in the medial striatum, which resembles the mammalian ventral striatum. The results identify portions of the hippocampal formation and the medial striatum as sites of plasticity associated with homing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
54.
In this paper, we first study strong positive-realness of sampled-data systems and introduce a measure called positive-realness gap index. We show that this index can be computed efficiently with a bisection method, and provide state space formulas for its computation. The importance of this index lies in that it is useful for robust stability analysis of sampled-data systems. An iterative procedure for computing an exact robust stability margin is given and illustrated through a numerical example.  相似文献   
55.
This paper proposes a power integrity control technique for dynamically controlling power supply voltage fluctuations for a device under test (DUT), and demonstrates its effectiveness for eliminating the overkills/underkills due to the difference of power supply impedance between an automatic test equipment (ATE) and a practical operating environment of the DUT. The proposed method injects compensation currents into the power supply nodes on the ATE system in a feed-forward manner such that the ATE power supply waveform matches with the one on the customer’s operating environment of the DUT. A method for calculating the compensation current is also described. Experimental results show that the proposed method can emulate the power supply voltage waveform under a customer’s operating condition and eliminate 95 % of overkills/underkills in the maximum operating frequency testing with 105 real silicon devices. Limitations and applications of the proposed method are also discussed.  相似文献   
56.
57.
58.
59.
Dysregulation of tumor necrosis factor-α (TNFα), a pro-inflammatory cytokine, causes several diseases, making it an important therapeutic target. Here, we identified a novel DNA aptamer against human TNFα using in vitro selection, which included a high exclusion pressure process against non-binding and weak binders through microbead-assisted capillary electrophoresis (MACE) in only three rounds. Among the 15 most enriched aptamers, Apt14 exhibited the highest inhibitory activity for the interaction between TNFα and its cognate receptor in mouse L929 cells. For further improving the bioactivity of the aptamer, dimerization programed by hybridization was evaluated, resulting in the Apt14 dimer exhibited a twofold higher binding affinity and stronger inhibition compared to the monomer counterpart. Rapid identification of bioactive aptamers using MACE in combination with facile dimerization by hybridization accelerates the discovery of novel bioactive aptamers, paving the way toward replacing current monoclonal antibody therapy with the less expensive and non-immunogenic aptamer therapy.  相似文献   
60.
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