全文获取类型
收费全文 | 1490篇 |
免费 | 109篇 |
国内免费 | 15篇 |
专业分类
电工技术 | 19篇 |
综合类 | 3篇 |
化学工业 | 355篇 |
金属工艺 | 37篇 |
机械仪表 | 71篇 |
建筑科学 | 65篇 |
矿业工程 | 1篇 |
能源动力 | 85篇 |
轻工业 | 134篇 |
水利工程 | 31篇 |
石油天然气 | 11篇 |
无线电 | 144篇 |
一般工业技术 | 320篇 |
冶金工业 | 62篇 |
原子能技术 | 42篇 |
自动化技术 | 234篇 |
出版年
2024年 | 4篇 |
2023年 | 16篇 |
2022年 | 65篇 |
2021年 | 108篇 |
2020年 | 96篇 |
2019年 | 106篇 |
2018年 | 96篇 |
2017年 | 98篇 |
2016年 | 119篇 |
2015年 | 55篇 |
2014年 | 91篇 |
2013年 | 137篇 |
2012年 | 98篇 |
2011年 | 109篇 |
2010年 | 80篇 |
2009年 | 57篇 |
2008年 | 52篇 |
2007年 | 31篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 22篇 |
1997年 | 9篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1614条查询结果,搜索用时 0 毫秒
41.
Ahmad Shaheryar Xu-Cheng Yin Hong-Wei Hao Zahid Mahmood Adnan O. M. Abuassba 《Artificial Intelligence Review》2018,50(3):341-382
Multilayered auto-associative neural architectures have widely been used in empirical sensor modeling. Typically, such empirical sensor models are used in sensor calibration and fault monitoring systems. However, simultaneous optimization of related performance metrics, i.e., auto-sensitivity, cross-sensitivity, and fault-detectability, is not a trivial task. Learning procedures for parametric and other relevant non-parametric empirical models are sensitive to optimization and regularization methods. Therefore, there is a need for active learning strategies that can better exploit the underlying statistical structure among input sensors and are simple to regularize and fine-tune. To this end, we investigated the greedy layer-wise learning strategy and denoising-based regularization procedure for sensor model optimization. We further explored the effects of denoising-based regularization hyper-parameters such as noise-type and noise-level on sensor model performance and suggested optimal settings through rigorous experimentation. A visualization procedure was introduced to obtain insight into the internal semantics of the learned model. These visualizations allowed us to suggest an implicit noise-generating process for efficient regularization in higher-order layers. We found that the greedy-learning procedure improved the overall robustness of the sensor model. To keep experimentation unbiased and immune to noise-related artifacts in real sensors, the sensor data were sampled from simulators of a nuclear steam supply system of a pressurized water reactor and a Tennessee Eastman chemical process. Finally, we compared the performance of an optimally regularized sensor model with auto-associative neural network, auto-associative kernel regression, and fuzzy similarity-based sensor models. 相似文献
42.
Hamed Safajou Mojgan Ghanbari Omid Amiri Hossein Khojasteh Farzad Namvar Sahar Zinatloo-Ajabshir Masoud Salavati-Niasari 《International Journal of Hydrogen Energy》2021,46(39):20534-20546
Recently, nanocomposite photocatalysts based on semiconductors have attracted much attention due to their suitable bandgap. Combination of tow of several semiconductors can slow down the electron-hole recombination. In this regard, we have depicted an eco-friendly and green fabrication technique to synthesize RGO/Cu nanocomposite by the reduction of graphene oxide and Cu2+ ion utilizing spearmint extract as a reductant and capping agent. The sample was identified by FTIR, XRD, FESEM, EDS, HRTEM, and CV. The results of photocatalytic performance revealed that RGO/Cu is an efficient catalyst for degrading organic pollutants. This compound can eliminate Rhodamine B (RhB) and Methylene blue (MB) 91.0% and 72.0%, respectively. 相似文献
43.
Fayyaz Ahmad Iftikhar Ahmad Zaibun Nisa Shahid Mahmood Ramay 《International journal of imaging systems and technology》2016,26(4):264-269
In this era, the neuroscientists get attention to find a network of brain which is activated in resting state of mind. It is challenging for any analytical technique to find out the connectivity among Brodmann areas of brain in resting state. To find network, a study was conducted in which brains are scan by functional magnetic resonance imaging of four healthy right handed individuals. Exploratory factor analysis was used to explore that which Brodmann areas are related to each other and then structural equation model has applied on explored factors (lobes) to find a network of activated brain in resting state. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 264–269, 2016 相似文献
44.
45.
The aim of this study was to fabricate antimicrobial calcium-alginate-based films containing the self-microemulsifying thyme essential oil (TEO) formulations using Tween 80 as the surfactant, and acetic (AA) or propionic (PA) acids as the cosurfactants. A Ca-alginate film containing nano-emulsified TEO as well as a neat Ca-alginate film were considered as the controls. The scanning electron microscopy micrographs showed a highly porous texture for SME films, which resulted in an increase in water vapor permeability and water absorption capacity of these films. The SME films released the TEO completely within 155 min and inhibited the growth of S. aureus and E. coli in in vitro antimicrobial tests. The population of S. aureus and E. coli reduced significantly in ground beef covered with SME films. The results of this study showed that self-microemulsifying TEO films could effectively increase the shelf life of ground beef by controlling its microbial population. 相似文献
46.
Kamran Ghasemzadeh Milad Ghahremani Taher Yousefi Amiri Angelo Basile Adolfo Iulianelli 《International Journal of Hydrogen Energy》2021,46(37):19768-19777
A comprehensive computational fluid dynamic model has been developed using COMSOL Multiphysics 5.4 software to predict the behavior of a membrane reactor in dehydrogenation of methylcyclohexane for hydrogen production. A reliable reaction kinetic of dehydrogenation reaction and a permeation mechanism of hydrogen through silica membrane have been used in computational fluid dynamic modeling. For performance comparison, an equivalent traditional fixed bed reactor without hydrogen removal has been also modeled. After model validation, it has been used to evaluate the operating parameters effect on the performance of both the silica membrane reactor and the equivalent traditional reactor as well. The operating temperature ranged between 473 and 553 K, pressure between 1 and 2.5 bar, sweep factor from ?6.22 to 25 and feed flow rate from 1 to 5 × 10?6 mol/s. The membrane reactor performed better than the equivalent traditional reactor, achieving as best result complete methylcyclohexane conversion and 96% hydrogen recovery. 相似文献
47.
Afarin Bahrami Zainal Abidin Talib Wan Mahmood Mat Yunus Kasra Behzad Mahnaz M. Abdi Fasih Ud Din 《International journal of molecular sciences》2012,13(11):14917-14928
Polypyrrole (PPy) and polypyrrole-carboxylic functionalized multi wall carbon nanotube composites (PPy/f-MWCNT) were synthesized by in situ chemical oxidative polymerization of pyrrole on the carbon nanotubes (CNTs). The structure of the resulting complex nanotubes was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The effects of f-MWCNT concentration on the electrical properties of the resulting composites were studied at temperatures between 100 K and 300 K. The Hall mobility and Hall coefficient of PPy and PPy/f-MWCNT composite samples with different concentrations of f-MWCNT were measured using the van der Pauw technique. The mobility decreased slightly with increasing temperature, while the conductivity was dominated by the gradually increasing carrier density. 相似文献
48.
49.
50.
Sotoodeh Mahmood Tajeripour Farshad Teimori Sadegh Jorgensen Kirk 《Multimedia Tools and Applications》2018,77(13):16833-16866
Multimedia Tools and Applications - Optical Music Recognition (OMR) can be divided into three main phases: (i) staff line detection and removal. The goal of this phase is to detect and to remove... 相似文献