全文获取类型
收费全文 | 9521篇 |
免费 | 27篇 |
专业分类
电工技术 | 137篇 |
综合类 | 2篇 |
化学工业 | 301篇 |
金属工艺 | 292篇 |
机械仪表 | 50篇 |
建筑科学 | 52篇 |
矿业工程 | 2篇 |
能源动力 | 40篇 |
轻工业 | 59篇 |
水利工程 | 1篇 |
无线电 | 337篇 |
一般工业技术 | 150篇 |
冶金工业 | 65篇 |
原子能技术 | 88篇 |
自动化技术 | 7972篇 |
出版年
2023年 | 10篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 15篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 14篇 |
2014年 | 225篇 |
2013年 | 191篇 |
2012年 | 771篇 |
2011年 | 2299篇 |
2010年 | 1129篇 |
2009年 | 971篇 |
2008年 | 692篇 |
2007年 | 602篇 |
2006年 | 461篇 |
2005年 | 579篇 |
2004年 | 530篇 |
2003年 | 580篇 |
2002年 | 279篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1974年 | 3篇 |
1943年 | 2篇 |
1941年 | 3篇 |
1936年 | 2篇 |
1924年 | 3篇 |
1909年 | 4篇 |
1908年 | 4篇 |
1905年 | 2篇 |
1904年 | 2篇 |
1901年 | 6篇 |
1898年 | 2篇 |
排序方式: 共有9548条查询结果,搜索用时 31 毫秒
1.
Khutoryan Eduard Kuleshov Alexei Ponomarenko Sergey Lukin Konstantin Tatematsu Yoshinori Tani Masahiko 《Journal of Infrared, Millimeter and Terahertz Waves》2021,42(6):671-683
Journal of Infrared, Millimeter, and Terahertz Waves - Various regimes of hybrid, bulk-surface, modes being excited in the clinotron oscillator with a sheet electron beam and nonuniform grating... 相似文献
2.
3.
Shafirah Samsuri Ngiam Li Jian Farah Wahida Jusoh Eduard Hernández Yáñez Noor Yahida Yahya 《化学工程与技术》2020,43(3):447-456
The application of solvent-aided crystallization (SAC) is based on the addition of a solvent, here 1-butanol, to crude biodiesel to catalyze the purification process by separating biodiesel from contaminants via crystallization process. Response surface methodology was applied to optimize the process parameters of SAC, represented by biodiesel purity. The purified biodiesel was analyzed by means of gas chromatography-mass spectrometry for the composition of the present fatty acid methyl ester (FAME). Under the predicted optimum process conditions within the experimental ranges for the highest biodiesel purity, the predicted biodiesel purity was 99.375 %. 相似文献
4.
Valentina Shkodich Nadezhda Temnikova Irina Boyko Heinrich Leicht Eduard Kraus Natalia Shkodich Oleg Stoyanov 《应用聚合物科学杂志》2020,137(16):48582
Using the methods of infrared spectroscopy (IRS) and X-ray photoelectron spectroscopy (XPS), it was shown that short-term high-energy machining of detonation nanodiamonds (DND) leads to structural changes in the crystal structure and functional composition of the surface layer on particles. The possibility of spontaneous formation for stable colloidal systems with a narrow size distribution of mechanically activated DND in phenol-formaldehyde oligomers (PFO) was established. By molecular spectroscopy it was revealed that π → π* interactions of the aromatic rings of PFO are caused by orientational phenomena as a result of hydrogen bonds between an activated DND surface and functional groups of PFO. The effect of DND concentration on the curing reaction parameters ofpsgr the phenol-formaldehyde oligomer was determined by differential scanning calorimetry (DSC). The concentration effect of mechanically activated nanodiamonds on the physical and mechanical characteristics of a composite material based on phenol-formaldehyde binder and polyamide paper (Nomex) was studied. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48582. 相似文献
5.
Bezene Detection: Deep Cavitand Self‐Assembled on Au NPs‐MWCNT as Highly Sensitive Benzene Sensing Interface (Adv. Funct. Mater. 26/2015) 下载免费PDF全文
6.
Carolin Braun Eduard Spuling Niklas B. Heine Murat Cakici Martin Nieger Stefan Brse 《Advanced Synthesis \u0026amp; Catalysis》2016,358(10):1664-1670
Pyridyl‐substituted [2.2]paracyclophanes build a multifunctional structural motif that is useful in material chemistry, catalysis and for luminescent structures. Nonetheless, there is still a lack of general methods for the synthesis of these structures tolerating easily accessible bromides as well as different isomeric pyridyl groups. Hence the coupling of functionalized [2.2]paracyclophanes with various substituted and functionalized pyridyl derivatives was achieved using Stille, Suzuki and Kumada coupling conditions. Hereby the Stille coupling of a [2.2]paracyclophane is presented as a versatile reaction for the formation of heteromeric [2.2]paracyclophane‐containing biaryl structures.
7.
Solid desiccant air-conditioning systems present a promising solution, in terms of performance level and environmental protection, pointing out their potential to be coupled with thermal solar or waste heat energy source. Nevertheless, these systems are characterized by constraints to the load they can satisfy, through the trade-off between the dehumidification cooling capacity and the latent load of the conditioned space. On that level, one has to note that, for steady environmental conditions, the conditioned space does not present unique value of load, but range of load, corresponding to an array of acceptable temperature and (usually relative) humidity values. In this work a methodology is proposed for the definition of the system's achievable working range under specific set of space (comfort) requirements. Through this approach, the systems present greater potential for covering the space requirements, thus presenting more possibilities on a design basis, and more flexible control strategies, as well. The proposed methodology is presented and discussed through the case study of a solar desiccant air-conditioning system coupled to a typical residential building. 相似文献
8.
9.
Steve Mansfield-Devine Author Vitae 《Network Security》2014,2014(8):14-17
10.
Richard MouldsAuthor Vitae 《Network Security》2014,2014(1):16-17