全文获取类型
收费全文 | 2625篇 |
免费 | 206篇 |
国内免费 | 25篇 |
专业分类
电工技术 | 51篇 |
综合类 | 10篇 |
化学工业 | 580篇 |
金属工艺 | 61篇 |
机械仪表 | 106篇 |
建筑科学 | 138篇 |
矿业工程 | 4篇 |
能源动力 | 181篇 |
轻工业 | 184篇 |
水利工程 | 42篇 |
石油天然气 | 25篇 |
无线电 | 250篇 |
一般工业技术 | 434篇 |
冶金工业 | 167篇 |
原子能技术 | 27篇 |
自动化技术 | 596篇 |
出版年
2023年 | 51篇 |
2022年 | 81篇 |
2021年 | 161篇 |
2020年 | 152篇 |
2019年 | 180篇 |
2018年 | 175篇 |
2017年 | 165篇 |
2016年 | 152篇 |
2015年 | 110篇 |
2014年 | 181篇 |
2013年 | 278篇 |
2012年 | 196篇 |
2011年 | 221篇 |
2010年 | 142篇 |
2009年 | 140篇 |
2008年 | 82篇 |
2007年 | 44篇 |
2006年 | 54篇 |
2005年 | 43篇 |
2004年 | 26篇 |
2003年 | 26篇 |
2002年 | 27篇 |
2001年 | 16篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 19篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 5篇 |
1993年 | 10篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 6篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有2856条查询结果,搜索用时 62 毫秒
1.
In this work, we designed a magnetically-separable Fe3O4-rGO-ZnO ternary catalyst, ZnO anchored on the surface of reduced graphene oxide (rGO)-wrapped Fe3O4 magnetic nanoparticles, where rGO, as an effective interlayer, can enhance the synergistic effect between ZnO and Fe3O4. The effects of three operational parameters, namely irradiation time, hydrogen peroxide dosage, and the catalyst dosage, on the photo-Fenton degradation of methylene blue and methyl orange were investigated. The results showed that the Fe3O4-rGO-ZnO had great potential for the destruction of organic compounds from wastewater using the Fenton chemical oxidation method at neutral pH. Repeatability of the photocatalytic activity after 5 cycles showed only a tiny drop in the catalytic efficiency. 相似文献
2.
Wireless Networks - Orthogonal frequency-division multiplexing with random multiple access (OFDRMA) is discussed for down-link communications, whereby a single base-station transmits information... 相似文献
3.
Amini Amir Jafari Azin Vafaei Mostafa Mahmoodian Mehrnoosh 《Journal of Materials Science: Materials in Electronics》2022,33(3):1293-1306
Journal of Materials Science: Materials in Electronics - The main weakness of polymer gas sensors is its stability. Here, we report stability enhancement of a 100 nm polypyrrole (PPy) thin... 相似文献
4.
Jabbari Ghazal Chalish Negin Ghiasian Ali Khorsandi Koohanestani Amir 《Wireless Personal Communications》2022,126(2):1301-1319
Wireless Personal Communications - The importance of environmental pollution has motivated the researchers to investigate the electrical power consumption of any emerging technology. Edge Computing... 相似文献
5.
Baig Md Amir Moinuddin Athar A. Khan E. Ghanbari M. 《Multimedia Tools and Applications》2022,81(6):7895-7916
Multimedia Tools and Applications - In this paper, blind image quality assessment (IQA) of Gaussian blurred images based on Discrete Fourier Transform (DFT) is proposed. The proposed work is based... 相似文献
6.
Kiani Farzad Seyyedabbasi Amir Mahouti Peyman 《Analog Integrated Circuits and Signal Processing》2021,109(3):599-609
Analog Integrated Circuits and Signal Processing - Modern time microwave stages require low power consumption, low size, low-noise amplifier (LNA) designs with high-performance measures. These... 相似文献
7.
Al-Musawi Tariq J. Mahvi Amir Hossein Khatibi Aram Dokht Balarak Davoud 《Journal of Porous Materials》2021,28(3):835-852
Journal of Porous Materials - In the present work, the adsorption performance of powdered activated carbon magnetized by iron(III) oxide magnetic nanoparticles (PAC@Fe3O4-MN) for the removal of... 相似文献
8.
Mozhgan Shahmirzaee Ahmad Iran Nejhad Amir Masoud Arabi 《Particulate Science and Technology》2019,37(1):110-117
ZnAl2O4 and ZnO nanostructure particles and in situ crystallization of zinc aluminate and zinc oxide coating layers on sintered α-Al2O3 and γ-Al2O3 granules by the microwave-assisted combustion method were investigated. For powders, the effects of solution pH value and for coated samples the influence of support type on the structure, microstructure, and photocatalytic activity of powders were studied. Results showed that variation of synthesis pH value caused to considerable change in agglomeration, specific surface area, obtaining up to 88 and 92% yields for zinc aluminate and zinc oxide nanoparticles, respectively. γ-alumina granules were more appropriate supports than the α-alumina ones because of the better photocatalytic activities and lower extent of the attritions for both zinc aluminate and zinc oxide coating layers. 相似文献
9.
Amir Movafeghi Yahaghi Effat Rokrok Behrouz Mirzapour Mahdi 《Russian Journal of Nondestructive Testing》2020,56(4):361-368
Russian Journal of Nondestructive Testing - The location of reinforcement bar in concrete, the bar corrosion, diameter and the depth below the surface are important factors in the evaluation of the... 相似文献
10.
Amir Naderolasli Mahnaz Hashemi Khoshnam Shojaei 《International Journal of Adaptive Control and Signal Processing》2020,34(3):298-313
An observer-based adaptive fuzzy backstepping approach is proposed for nonlinear systems with respect to fractional-order differential equations, unmatched uncertainties, unmeasured states, and actuator faults. The approximation capability of fuzzy logic system and minimal learning parameter approaches are applied to identify uncertain functions in a simultaneous manner. For estimating the unavailable conditions, a fuzzy fractional-order state-observer is extended. Applying fault-tolerant approach in a backstepping design methodology would provide a new fault-tolerant adaptive fuzzy output-feedback approach for fractional-order strict-feedback systems. This control structure would assure the considered system stability through selection of the appropriate Lyapunov candidate function. Two numerical simulations are run to exhibit the validity herein. 相似文献