全文获取类型
收费全文 | 2314篇 |
免费 | 113篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 48篇 |
综合类 | 7篇 |
化学工业 | 615篇 |
金属工艺 | 49篇 |
机械仪表 | 20篇 |
建筑科学 | 137篇 |
矿业工程 | 10篇 |
能源动力 | 67篇 |
轻工业 | 275篇 |
水利工程 | 12篇 |
石油天然气 | 2篇 |
无线电 | 175篇 |
一般工业技术 | 378篇 |
冶金工业 | 309篇 |
原子能技术 | 8篇 |
自动化技术 | 317篇 |
出版年
2023年 | 33篇 |
2022年 | 18篇 |
2021年 | 105篇 |
2020年 | 67篇 |
2019年 | 54篇 |
2018年 | 62篇 |
2017年 | 45篇 |
2016年 | 75篇 |
2015年 | 59篇 |
2014年 | 95篇 |
2013年 | 113篇 |
2012年 | 95篇 |
2011年 | 127篇 |
2010年 | 90篇 |
2009年 | 78篇 |
2008年 | 78篇 |
2007年 | 87篇 |
2006年 | 57篇 |
2005年 | 47篇 |
2004年 | 55篇 |
2003年 | 43篇 |
2002年 | 41篇 |
2001年 | 19篇 |
2000年 | 31篇 |
1999年 | 20篇 |
1998年 | 54篇 |
1997年 | 45篇 |
1996年 | 33篇 |
1995年 | 27篇 |
1994年 | 30篇 |
1993年 | 25篇 |
1992年 | 36篇 |
1991年 | 20篇 |
1990年 | 33篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 26篇 |
1986年 | 18篇 |
1985年 | 32篇 |
1984年 | 25篇 |
1983年 | 27篇 |
1982年 | 19篇 |
1981年 | 24篇 |
1979年 | 14篇 |
1978年 | 25篇 |
1977年 | 16篇 |
1976年 | 19篇 |
1972年 | 15篇 |
1970年 | 14篇 |
1963年 | 13篇 |
排序方式: 共有2429条查询结果,搜索用时 15 毫秒
1.
Konstantinos Spyrou Matteo Calvaresi Evmorfia K. Diamanti Theodoros Tsoufis Dimitrios Gournis Petra Rudolf Francesco Zerbetto 《Advanced functional materials》2015,25(2):263-269
Experimental and theoretical studies are performed in order to illuminate, for first time, the intercalation mechanism of polycyclic aromatic molecules into graphite oxide. Two representative molecules of this family, aniline and naphthalene amine are investigated. After intercalation, aniline molecules prefer to covalently connect to the graphene oxide matrix via chemical grafting, while napthalene amine molecules bind with the graphene oxide surface through π–π interactions. The presence of intercalated aromatic molecules between the graphene oxide layers is demonstrated by X‐ray diffraction, while the type of interaction between graphene oxide and polycyclic organic molecules is elucidated by X‐ray photoelectron spectroscopy. Combined quantum mechanical and molecular mechanical calculations describe the intercalation mechanism and the aniline grafting, rationalizing the experimental data. The present work opens new perspectives for the interaction of various aromatic molecules with graphite oxide and the so‐called “intercalation chemistry”. 相似文献
2.
Kooij Julian F. P. Flohr Fabian Pool Ewoud A. I. Gavrila Dariu M. 《International Journal of Computer Vision》2019,127(3):239-262
International Journal of Computer Vision - Anticipating future situations from streaming sensor data is a key perception challenge for mobile robotics and automated vehicles. We address the problem... 相似文献
3.
Annika Jahn Anton Hoffmann Luisa Blaesing Fabian Kunde Martin Bertau Martina Bremer Steffen Fischer 《化学,工程师,技术》2020,92(11):1733-1740
The enzymatic conversion of lignins, possibly in combination with electrochemical oxidation, makes aromatics such as syringol, guaiacol, vanillin and catechol available in the qualities required by the fragrance industry. The lignins were obtained by soda digestion from wheat straw and Miscanthus, characterized and then converted with laccases. The overall yield amounted up to 9 wt % with a product spectrum confined to four substances. Catechol was the major product, with a fraction of ≈75 %. It can easily be isolated by extraction with acetone. 相似文献
4.
Makrina A. Chairopoulou Fabian Kratzer Roland Gross Michael Herrmann Ulrich Teipel 《化学工程与技术》2020,43(5):904-912
Thermogravimetric analysis of a coccolith-containing biogenic broth showed a three-step degradation process. According to this system behavior, the biogenic broth was heated to specific temperatures and characterized in terms of its morphology, surface chemistry, and crystallinity. The elemental and organic composition of the treated samples was also evaluated and compared to the reference material. The presented results were acquired in an effort to exploit pretreatment scenarios for such a biogenic system that would improve and support a separation process. 相似文献
5.
6.
Rudolf Habison 《International Journal of Project Management》1985,3(3):178-181
Meeting time and cost objectives in complex projects involves specific problems and risks. An attempt is made to analyse the components of total cost increase of a project caused by time delay. An outline is given as to how these considerations can be used to estimate cost increases in investors' decision situations as well as to ascertain fair contractual penalties and claims for compensation and for the evaluation of justified project acceleration costs. 相似文献
7.
8.
9.
10.