全文获取类型
收费全文 | 835篇 |
免费 | 27篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 24篇 |
综合类 | 2篇 |
化学工业 | 175篇 |
金属工艺 | 28篇 |
机械仪表 | 25篇 |
建筑科学 | 28篇 |
矿业工程 | 1篇 |
能源动力 | 83篇 |
轻工业 | 55篇 |
水利工程 | 10篇 |
石油天然气 | 21篇 |
无线电 | 80篇 |
一般工业技术 | 138篇 |
冶金工业 | 43篇 |
原子能技术 | 21篇 |
自动化技术 | 132篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 17篇 |
2021年 | 46篇 |
2020年 | 27篇 |
2019年 | 29篇 |
2018年 | 51篇 |
2017年 | 29篇 |
2016年 | 42篇 |
2015年 | 24篇 |
2014年 | 36篇 |
2013年 | 82篇 |
2012年 | 39篇 |
2011年 | 51篇 |
2010年 | 39篇 |
2009年 | 40篇 |
2008年 | 25篇 |
2007年 | 37篇 |
2006年 | 25篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 12篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1987年 | 2篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有866条查询结果,搜索用时 78 毫秒
1.
Safa Meraghni Labib Sadek Terrissa Meiling Yue Jian Ma Samir Jemei Noureddine Zerhouni 《International Journal of Hydrogen Energy》2021,46(2):2555-2564
Prognostics and health management of proton exchange membrane fuel cell (PEMFC) systems have driven increasing research attention in recent years as the durability of PEMFC stack remains as a technical barrier for its large-scale commercialization. To monitor the health state during PEMFC operation, digital twin (DT), as a smart manufacturing technique, is applied in this paper to establish an ensemble remaining useful life prediction system. A data-driven DT is constructed to integrate the physical knowledge of the system and a deep transfer learning model based on stacked denoising autoencoder is used to update the DT with online measurement. A case study with experimental PEMFC degradation data is presented where the proposed data-driven DT prognostics method has applied and reached a high prediction accuracy. Furthermore, the predicted results are proved to be less affected even with limited measurement data. 相似文献
2.
Enas Taha Sayed Hussain Alawadhi A.G. Olabi Aisha Jamal Menna Salah Almahdi Juiaria Khalid Mohammad Ali Abdelkareem 《International Journal of Hydrogen Energy》2021,46(8):5975-5983
Microbial fuel cell (MFC) is a promising technology for simultaneous wastewater treatment and energy harvesting. The properties of the anode material play a critical role in the performance of the MFC. In this study, graphene oxide was prepared by a modified hummer's method. A thin layer of graphene oxide was incorporated on the carbon brush using an electrophoretic technique. The deoxygenated graphene oxide formed on the surface of the carbon brush (RGO-CB) was investigated as a bio-anode in MFC operated with real wastewater. The performance of the MFC using the RGO-CB was compared with that using plain carbon brush anode (PCB). Results showed that electrophoretic deposition of graphene oxide on the surface of carbon brush significantly enhanced the performance of the MFC, where the power density increased more than 10 times (from 33 mWm?2 to 381 mWm?2). Although the COD removal was nearly similar for the two MFCs, i.e., with PCB and RGO-CB; the columbic efficiency significantly increased in the case of RGO-CB anode. The improved performance in the case of the modified electrode was related to the role of the graphene in improving the electron transfer from the microorganism to the anode surface, as confirmed from the electrochemical impedance spectroscopy measurements. 相似文献
3.
AbstractGeneralized thermoelastic interactions due to three-phase-lag time-nonlocal heat transfer in a Kelvin-Voigt type infinitely extended visco-thermoelastic continuum with cylindrical cavity has been investigated. The two-temperature generalized thermoelasticity theory has also been taken into account. The problem has been solved in the domain of Laplace on the assumption that the surface of the cavity is free from traction and is subjected to a smooth and time-dependent-heating effect. Laplace inversion of the transformed solutions has been carried out numerically. The obtained numerical data for different considerations are plotted in graphs to study the effects of time-nonlocal parameter, two-temperature parameter and visco-thermoelastic relaxation parameter on different thermoelastic quantities of physical interest. 相似文献
4.
Conductance measurements are reported for s-alkylisothiouronium bromide, iodide and picrate salts in the dipolar aprotic solvent DMSO at 25°C. The data were analysed by Fuoss's equation (1975–1980) for 1:1 electrolytes, from which the values of Λ0, the Gurney's cosphere diameter R and KA are obtained. The results are discussed in the light of the recorded values of the constants KR and KS and the free energy term Gs. 相似文献
5.
6.
Jan Langer Marian Klasztorny Salah El-Sayed El-Bagalaty' 《International journal for numerical methods in engineering》1992,33(5):889-905
The paper presents a family of methods with postintegration, for numerical integration of non-linear dynamic equations of motion of discrete systems. Both explicit and implicit algorithms of these methods are conditionally stable, but can give solutions of accuracy of a few orders higher than the known methods with preintegration, corresponding to them. A general analysis of stability and accuracy of single-step methods is carried out. The postintegration methods have been tested on a single-degree-of-freedom non-linear system. 相似文献
7.
Mohamed Salah Foda 《Journal of the science of food and agriculture》1981,32(11):1109-1114
A fermentation procedure using wheys from buffalo milk, sweet rennet and salted wheys containing up to 15% NaC1, and based on the selection of salt-tolerant fungal cultures for production of microbial proteins and some economically important enzymes, is described. Certain strains of Aspergillus flavus, A. niger, A. ochraceus and A. terreus gave yields of mycelium ranging between 1.5 and 30 g on a dry weight basis. Strong proteolytic activities were exhibited by A. ochraceus, A. flavus and, to a lesser extent, by A. niger in the presence of salt up to 10% as final concentration. Powerful milk-clotting activities were also detected in culture supernatants of A. flavus and A. ochraceus. Extracellular β-galactosidases were released in to the culture fluids of these fungal strains with variable activities, depending upon the salt content of the growth medium. The application of the procedure is discussed. 相似文献
8.
9.
10.