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   566篇
  免费   35篇
  国内免费   3篇
电工技术   5篇
综合类   1篇
化学工业   101篇
金属工艺   14篇
机械仪表   20篇
建筑科学   11篇
能源动力   33篇
轻工业   31篇
水利工程   9篇
石油天然气   1篇
无线电   94篇
一般工业技术   132篇
冶金工业   25篇
原子能技术   2篇
自动化技术   125篇
  2024年   2篇
  2023年   12篇
  2022年   35篇
  2021年   38篇
  2020年   21篇
  2019年   33篇
  2018年   41篇
  2017年   23篇
  2016年   22篇
  2015年   19篇
  2014年   24篇
  2013年   51篇
  2012年   41篇
  2011年   29篇
  2010年   31篇
  2009年   22篇
  2008年   26篇
  2007年   21篇
  2006年   25篇
  2005年   19篇
  2004年   9篇
  2003年   13篇
  2002年   10篇
  2001年   10篇
  2000年   2篇
  1999年   5篇
  1998年   4篇
  1997年   3篇
  1996年   3篇
  1994年   3篇
  1993年   1篇
  1992年   4篇
  1990年   1篇
  1978年   1篇
排序方式: 共有604条查询结果,搜索用时 15 毫秒
601.
Solar energy is widely acknowledged as one of the most promising renewable energy sources for addressing future electrical energy demands. Photovoltaic modules (PVms) convert solar energy into electrical energy and are highly sensitive to nonlinear changes in environmental circumstances, which in turn affect the generation of electricity from the PVms. The module-level maximum power point tracking (MPPT) of PVms using multiple input converters (MICs) is the effective and cost-efficient method among all the methodologies and techniques. MICs, on the other hand, suffer from a cross power-sharing difficulty due to their modular design, which implies that the individual cells that make up the device impact on each other's power-sharing operation. The solution to which have been ignored in the literature. The objective of this paper is to employ the maximum power point resistance (MPPR) approach to determine an appropriate duty ratio range for the proposed MIC while taking into consideration the cross effect of different cells. Steady-state, power loss, and efficiency analysis of the proposed MIC structure with less component count have been included. The proposed approach has been validated experimentally and further, a comparative analysis with recently reported various approaches has also been included to prove the suitability of the proposed approach.  相似文献   
602.
Si–O deoxidation equilibria in liquid steel are not reliably known, especially in the high silicon concentration range. Herein, Si–O deoxidation equilibria in liquid steel at 1823–1873 K have been investigated for a wide range of silicon concentrations. Thermodynamic analysis was carried out using Wagner's interaction parameter formalism (WIPF) and FactSage 8.1. The first and second-order cross-interaction parameters estimated at 1873 K are as follows: e O Si = 0.086 , e Si O = 0.154 , r O Si = 0.0016 . Moreover, nonmetallic inclusion characteristics were also investigated for varying silicon concentrations.  相似文献   
603.
Verma  Manish  Mishra  Guru Prasad 《SILICON》2022,14(7):3439-3448
Silicon - A modified structure of Anti reflection coating (ARC) less wafer based 200 μm thick c-Si Solar cell with tunnel oxide passivated contact (TOPCon) solar cell is proposed with...  相似文献   
604.
Recent advances in 2D magnetism have heightened interest in layered magnetic materials due to their potential for spintronics. In particular, layered semiconducting antiferromagnets exhibit intriguing low-dimensional semiconducting behavior with both charge and spin as carrier controls. However, synthesis of these compounds is challenging and remains rare. Here, first-principles based high-throughput search is conducted to screen potentially stable mixed metal phosphorous trichalcogenides (MMP2X6, where M and M are transition metals and X is a chalcogenide) that have a wide range of tunable bandgaps and interesting magnetic properties. Among the potential candidates, a stable semiconducting layered magnetic material, CdFeP2Se6, that exhibits a short-range antiferromagnetic order at TN = 21 K with an indirect bandgap of 2.23 eV is successfully synthesized . This work suggests that high-throughput screening assisted synthesis can be an effective method for layered magnetic materials discovery.  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