全文获取类型
收费全文 | 4036篇 |
免费 | 298篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 45篇 |
综合类 | 13篇 |
化学工业 | 978篇 |
金属工艺 | 145篇 |
机械仪表 | 107篇 |
建筑科学 | 148篇 |
矿业工程 | 27篇 |
能源动力 | 176篇 |
轻工业 | 646篇 |
水利工程 | 33篇 |
石油天然气 | 20篇 |
无线电 | 244篇 |
一般工业技术 | 823篇 |
冶金工业 | 170篇 |
原子能技术 | 55篇 |
自动化技术 | 714篇 |
出版年
2023年 | 49篇 |
2022年 | 42篇 |
2021年 | 113篇 |
2020年 | 101篇 |
2019年 | 127篇 |
2018年 | 184篇 |
2017年 | 178篇 |
2016年 | 169篇 |
2015年 | 161篇 |
2014年 | 223篇 |
2013年 | 433篇 |
2012年 | 226篇 |
2011年 | 265篇 |
2010年 | 282篇 |
2009年 | 222篇 |
2008年 | 150篇 |
2007年 | 110篇 |
2006年 | 81篇 |
2005年 | 46篇 |
2004年 | 81篇 |
2003年 | 65篇 |
2002年 | 70篇 |
2001年 | 54篇 |
2000年 | 46篇 |
1999年 | 34篇 |
1998年 | 70篇 |
1997年 | 64篇 |
1996年 | 47篇 |
1995年 | 33篇 |
1994年 | 29篇 |
1993年 | 38篇 |
1992年 | 25篇 |
1991年 | 17篇 |
1990年 | 14篇 |
1989年 | 18篇 |
1988年 | 13篇 |
1986年 | 11篇 |
1985年 | 20篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 25篇 |
1981年 | 39篇 |
1980年 | 30篇 |
1979年 | 24篇 |
1978年 | 30篇 |
1977年 | 27篇 |
1976年 | 38篇 |
1975年 | 26篇 |
1974年 | 18篇 |
1973年 | 23篇 |
排序方式: 共有4344条查询结果,搜索用时 15 毫秒
1.
2.
Golam Haider Krishna Sampathkumar Tim Verhagen Lukáš Nádvorník Farjana J. Sonia Václav Valeš Jan Sýkora Peter Kapusta Petr Němec Martin Hof Otakar Frank Yang-Fang Chen Jana Vejpravová Martin Kalbáč 《Advanced functional materials》2021,31(29):2102196
Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability. 相似文献
3.
Machine Learning - Anomaly detection is a hard data analysis process that requires constant creation and improvement of data analysis algorithms. Using traditional clustering algorithms to analyse... 相似文献
4.
Mobile Networks and Applications - Solid fuels combustion is rather complicated because there is always environment pollution by emissions, mainly by particulate matter. The efforts of heat sources... 相似文献
5.
Aurita Butkevičiūtė Darius Kviklys Kristina Zymonė Raimondas Raudonis Jonas Viškelis 《International Journal of Food Properties》2018,21(1):1716-1727
A new technique for the rapid detection and analysis of triterpenic compounds in apple extracts using HPLC was developed and validated. The main advantage of this technique is the short duration of the analysis – this makes this technique superior to others currently applied for the routine HPLC analysis of triterpenic compounds. The developed, optimized, and validated technique was used for the evaluation of triterpenic compounds in samples of different cultivars of apples, their peels, and flesh. In total, four triterpenic compounds were isolated and identified. Ursolic acid was the dominant compound in all the tested apple samples. The highest amounts of triterpenic compounds were detected in the peels of the ‘Lodel’ apple cultivar, and thus apples of this cultivar may be potentially useful for the isolation of individual compounds and the production of functional food and dietary supplements. 相似文献
6.
7.
8.
Jiří Bednář Ladislav Svoboda Pavel Mančík Richard Dvorský 《Materials Science & Technology》2019,35(7):775-781
Zinc sulphide (ZnS) nanoparticles were prepared by an aerosol method from zinc acetate and sodium sulphide (Na2S) aqueous solutions. Aqueous solution of zinc acetate was dispersed into the form of microdroplets, which were introduced by airflow to vigorously stirred aqueous solution of Na2S, which was in excess. Microdroplets served as microreactors, so the reaction took place only in limited volume. Particle size distribution was studied by transmission electron microscopy and by dynamic light scattering measurements. In this work, the equation that allows us to predict the final size distribution of ZnS nanoparticles using exact concentration of zinc acetate was derived and ZnS nanoparticles with predicted mean particle diameter around 50 and 70?nm were successfully synthetised. 相似文献
9.
10.