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   374篇
  免费   20篇
  国内免费   1篇
电工技术   11篇
综合类   2篇
化学工业   85篇
金属工艺   14篇
机械仪表   23篇
建筑科学   24篇
能源动力   26篇
轻工业   18篇
水利工程   1篇
石油天然气   2篇
无线电   32篇
一般工业技术   60篇
冶金工业   10篇
原子能技术   9篇
自动化技术   78篇
  2024年   1篇
  2023年   10篇
  2022年   7篇
  2021年   29篇
  2020年   27篇
  2019年   31篇
  2018年   35篇
  2017年   21篇
  2016年   36篇
  2015年   14篇
  2014年   24篇
  2013年   42篇
  2012年   19篇
  2011年   30篇
  2010年   20篇
  2009年   11篇
  2008年   6篇
  2007年   4篇
  2006年   6篇
  2005年   3篇
  2004年   3篇
  2002年   1篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1994年   3篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
排序方式: 共有395条查询结果,搜索用时 0 毫秒
391.
Mehrdad  Farzad  Ahangari  Zahra 《SILICON》2022,14(13):7567-7576
Silicon - In this paper, we comprehensively assess the unique features, feasibility and limitations of dual material gate fin field effect transistor for tuning the threshold voltage in nanoscale...  相似文献   
392.
This paper presents applications of a new class of fibre optic acoustic emission (FOAE) sensor to monitor the operation of fluidized bed reactors used in polyethylene production. Specifically, the sensor was implemented to detect undesired, abnormal phenomena related to particle agglomeration, wall sheeting, fine overflow, and variations in the superficial gas velocity. The experiments were executed using a fluidized bed cold model setup for polyethylene powders with average particle sizes of 250, 1000, and 2000 μm. The results demonstrated that the presence of agglomerated particles in the fluidized bed reactor increases the kurtosis of the acoustic emission (AE) signal. Furthermore, the overflow of small particles can be detected by mounting the FOAE sensor below the gas distributor plate and monitoring an increase in the root mean square (RMS) of the AE signal. The AE signal RMS increased with the rising superficial gas velocity. Besides, forming a sheet layer on the reactor wall decreased the AE signal RMS. The proposed sensor's main benefits are its simple design, rapid response to abnormal conditions in the fluidized bed reactor, immunity against electromagnetic noise, high-temperature resistance, and safety in hazardous areas.  相似文献   
393.
Soluble N‐functionalized basic and cationic polysaccharides have been synthesized using polysaccharide phenyl carbonate as a precursor. The products and intermediates were thoroughly characterized by conventional methods. The quaternization of amino intermediates in various conditions was studied. Moreover, the potential of basic polymers as green and selective catalysts in Knoevenagel reaction was investigated. In all cases, only one isomer was obtained.  相似文献   
394.
Journal of Inorganic and Organometallic Polymers and Materials - Dimethyltin(IV) complex SnMe2(NCS)2 form two coordination polymers when react with the tetradentate 2,2′-bipyrimidine (bpym)...  相似文献   
395.
The present framework proposed the development of a Hybrid Rubber-Concrete Isolation Slab System (HRCISS) to support building structures subjected to horizontal and vertical vibration due to ground motion and machine or equipment operation in the structure. Given that the effect of the shape factor on both horizontal and vertical stiffness has yet to be reported, the proposed composite system was comprised of two layers under the nodal points of the upper layer near the slab corners with four High Damping Rubber (HDR) components positioned between the slab layers to dissipate multidirectional (horizontal and vertical directions) vibrations. The ABAQUS software was utilized to model the finite element model (FEM) and simulate the HRCISS subjected to cyclic horizontal and vertical displacements. For the optimal HDR design, the model was applied in five 3-story buildings, and the effect of distinct shape factors (0 < S < 2) of the HDR bearings—the ratio of bearing's loaded area to unloaded area (free to bulge)—within the hybrid system was evaluated. For each building with a specific HDR shape factor, the HRCISS was installed in the first, second, and third stories, separately, to investigate the influence of the installation level of the isolation system on the overall structural performance. The multistory buildings were subjected to two types of vibration loads: the interior machine-induced vibrations, and the exterior seismic-induced vibrations in the horizontal and vertical directions. Based on the results, the FEM results proved the significant influence of the shape factors on the dynamic response of the HRCISS under both interior and exterior 3D vibrations when applied in multistory buildings. The lateral drift of the three-story one-bay buildings decreased with the decrement of shape factor with buildings of HRCISS installed in 1st story recording more reduction. Moreover, the deflection in the structural slab under the HRCISS decreased for lower shape factor bearings. Nevertheless, the reduced deflection was less affected by the level of the machine-equipped story. The rubber layer also stiffened in shear and compression directions with a higher shape factor.  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