全文获取类型
收费全文 | 453篇 |
免费 | 20篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 89篇 |
金属工艺 | 8篇 |
机械仪表 | 17篇 |
建筑科学 | 15篇 |
能源动力 | 39篇 |
轻工业 | 30篇 |
石油天然气 | 2篇 |
无线电 | 72篇 |
一般工业技术 | 82篇 |
冶金工业 | 25篇 |
自动化技术 | 90篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 9篇 |
2021年 | 13篇 |
2020年 | 23篇 |
2019年 | 21篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 20篇 |
2013年 | 40篇 |
2012年 | 13篇 |
2011年 | 22篇 |
2010年 | 18篇 |
2009年 | 21篇 |
2008年 | 18篇 |
2007年 | 8篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有473条查询结果,搜索用时 0 毫秒
471.
Transmissive Labyrinthine Acoustic Metamaterial-Based Holography for Extraordinary Energy Harvesting
Shubhi Bansal Christabel Choi James Hardwick Biswajoy Bagchi Manish K. Tiwari Sriram Subramanian 《Advanced Engineering Materials》2023,25(4):2370017
Conventional energy sources are continuously depleting, and the world is actively seeking new green and efficient energy solutions. Enormous amounts of acoustic energy are dissipated daily, but the low intensity and limited efficiency of current harvesting techniques are preventing its adoption as a ubiquitous method of power generation. Herein, a strategic solution to increase acoustic energy harvesting efficiency using a specially designed metamaterial is implemented. A scalable transmissive labyrinthine acoustic metamaterial (LAM) is designed, developed, and employed to maximize ultrasound (40 kHz) capture over its large surface area (>27 k mm2), which is focused onto a piezoelectric film (78.6 mm2), thus magnifying incident sound pressure by 13.6 times. Three different piezoelectric films – two commercial and one lab-made nanocomposite film are tested with LAM in the acoustic energy harvesting system. An extraordinary voltage gain of 157–173% and a maximum power gain of 272% using the LAM compared to the case without the LAM are achieved. Multipoint focusing using holographic techniques, showcasing acoustic patterning to allow on-demand simultaneous harvesting in separate locations, is demonstrated. Our versatile approach for high-intensity acoustic energy harvesting opens future opportunities to exploit sound energy as a resource to contribute toward global sustainability. 相似文献
472.
Silicon - The investigation aims to study the microstructure and mechanical property changes of various silicon added WE43 alloys. With the increase in Si addition, the Mg2Si phase forms randomly... 相似文献
473.
Intended for good productivity and perfect operation of the solar power grid a failure-free system is required. Therefore, thermal image processing with the thermal camera is the latest non-invasive (without manual contact) type fault identification technique which may give good precision in all aspects. The soiling issue, which is major productivity affecting factor may import from several reasons such as dust on the wind, bird mucks, etc. The efficient power production sufferers due to accumulated soil deposits reaching from 1%–7% in the county, such as India, to more than 25% in middle-east countries country, such as Dubai, Kuwait, etc. This research offers a solar panel soiling detection system built on thermal imaging which powers the inspection method and mitigates the requirement for physical panel inspection in a large solar production place. Hence, in this method, solar panels can be verified by working without disturbing production operation and it will save time and price of recognition. India ranks 3rd worldwide in the usage use age of Photovoltaic (PV) panels now and it is supported about 8.6% of the Nation’s electricity need in the year 2020. In the meantime, the installed PV production areas in India are aged 4–5 years old. Hence the need for inspection and maintenance of installed PV is growing fast day by day. As a result, this research focuses on finding the soiling hotspot exactly of the working solar panels with the help of Principal Components Thermal Analysis (PCTA) on MATLAB Environment. 相似文献