全文获取类型
收费全文 | 2701篇 |
免费 | 179篇 |
国内免费 | 27篇 |
专业分类
电工技术 | 51篇 |
综合类 | 12篇 |
化学工业 | 604篇 |
金属工艺 | 63篇 |
机械仪表 | 106篇 |
建筑科学 | 140篇 |
矿业工程 | 4篇 |
能源动力 | 184篇 |
轻工业 | 186篇 |
水利工程 | 44篇 |
石油天然气 | 27篇 |
无线电 | 252篇 |
一般工业技术 | 439篇 |
冶金工业 | 167篇 |
原子能技术 | 27篇 |
自动化技术 | 601篇 |
出版年
2024年 | 8篇 |
2023年 | 51篇 |
2022年 | 98篇 |
2021年 | 171篇 |
2020年 | 152篇 |
2019年 | 181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 | 55篇 |
2005年 | 43篇 |
2004年 | 27篇 |
2003年 | 26篇 |
2002年 | 27篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 14篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 6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 |
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2907条查询结果,搜索用时 0 毫秒
21.
Tariq Junaid Armghan Ammar Ijaz Amir Ashraf Imran 《Multimedia Tools and Applications》2021,80(14):21449-21464
Multimedia Tools and Applications - The High Efficiency Video Coding (HEVC) efficiently reduces the size of the multimedia contents, but at the cost of high computation complexity. In order to make... 相似文献
22.
Mohammad-Ali Saeimi-Sadigh Amin Paykani Amir Afkar Dehghan Aminollah 《中南工业大学学报(英文版)》2014,(4):1307-1312
V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-shape plates were carried out using finite element analysis package ABAQUS. Various geometries of V-shape plates with and without interlayer of materials like Al-foams and honeycomb were employed to analyze their effects on the deformation of the plate and applied stresses and strains. The results obtained show that application of metallic foams leads to better response of the plate and consequently results in more energy dissipation, less dame to vehicle and enhances crew survivability. 相似文献
23.
Hossein Derakhshankhah Rana Jahanban-Esfahlan Somayeh Vandghanooni Sattar Akbari-Nakhjavani Bakhshali Massoumi Babak Haghshenas Aram Rezaei Amir Farnudiyan-Habibi Hadi Samadian Mehdi Jaymand 《应用聚合物科学杂志》2021,138(24):50578
Gelatin (Gel)-based pH- and thermal-responsive magnetic hydrogels (MH-1 and MH-2) were designed and developed as novel drug delivery systems (DDSs) for cancer chemo/hyperthermia therapy. For this goal, Gel was functionalized with methacrylic anhydride (GelMA), and then copolymerized with (2-dimethylaminoethyl) methacrylate (DMAEMA) monomer in the presence of methacrylate-end capped magnetic nanoparticles (MNPs) as well as triethylene glycol dimethacrylate (TEGDMA; as crosslinker). Afterward, a thiol-end capped poly(N-isopropylacrylamide) (PNIPAAm-SH) was synthesized through an atom transfer radical polymerization technique, and then attached onto the hydrogel through “thiol-ene” click grafting. The preliminary performances of developed MHs for chemo/hyperthermia therapy of human breast cancer was investigated through the loading of doxorubicin hydrochloride (Dox) as an anticancer agent followed by cytotoxicity measurement of drug-loaded DDSs using MTT assay by both chemo- and chemo/hyperthermia-therapies. Owing to porous morphologies of the fabricated magnetic hydrogels according to scanning electron microscopy images and strong physicochemical interactions (e.g., hydrogen bonding) the drug loading capacities of the MH-1 and MH-2 were obtained as 72 ± 1.4 and 77 ± 1.8, respectively. The DDSs exhibited acceptable pH- and thermal-triggered drug release behaviors. The MTT assay results revealed that the combination of hyperthermia therapy and chemotherapy has synergic effect on the anticancer activities of the developed DDSs. 相似文献
24.
The compulsion to use bioplastics has increased significantly today. One of the important aspects of plastics is their recyclability. Therefore, the important question of this research is that although bio-based compounds containing starch are sensitive to thermal-mechanical recycling processes, are such products thermally recyclable? To answer the question, polypropylene (PP)/thermoplastic starch (TPS) compound granules were extruded up to five times, and in the other part, single-extruded granules were blended at different ratios with virgin granules by extrusion. In order to characterize these samples, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, rotational disc rheometry, tensile properties, and appearance evaluation were used. The results showed that it is possible to recycle PP/TPS granules up to four times repetition of the extrusion operation and the fifth repetition also showed slight changes. There was also a blend of single-extruded granules with virgin material up to a 50:50% composition without significant variation. 相似文献
25.
Facial features under variant-expressions and partial occlusions could have degrading effect on overall face recognition performance. As a solution, we suggest that the contribution of these features on final classification should be determined. In order to represent facial features contribution according to their variations, we propose a feature selection process that describes facial features as local independent component analysis(ICA) features. These local features are acquired using locally lateral subspace(LLS) strategy.Then, through linear discriminant analysis(LDA) we investigate the intraclass and interclass representation of each local ICA feature and express each feature s contribution via a weighting process. Using these weights, we define the contribution of each feature at local classifier level. In order to recognize faces under single sample constraint, we implement LLS strategy on locally linear embedding(LLE) along with the proposed feature selection. Additionally, we highlight the efficiency of the implementation of LLS strategy. The overall accuracy achieved by our approach on datasets with different facial expressions and partial occlusions such as AR, JAFFE,FERET and CK+ is 90.70%. We present together in this paper survey results on face recognition performance and physiological feature selection performed by human subjects. 相似文献
26.
Ghazanfar Shahgholian Amir Movahedi Jawad Faiz 《International Journal of Control, Automation and Systems》2015,13(2):398-409
Thyristor controlled series capacitor (TCSC) can regulate line impedance and therefore increase transferred power of the system. On the other hand power system stabilizer (PSS) increases dynamic stability of generator. To enhance the stability, combination of TCSC and PSS can be applied, and in such a case coordination of TCSC and PSS is essential. This paper applies this combined controller in order to enhance the stability of multi-machine system. Parameters of these controllers are optimized by velocity update relaxation particle swarm optimization (VURPSO) algorithm and Genetic algorithm (GA). The simulation results show that the combination of VURPSO algorithm and GA leads to a better design and stability. 相似文献
27.
Fouzhan Hosseini Amir Fijany Saeed Safari Jean-Guy Fontaine 《Journal of Real-Time Image Processing》2013,8(4):421-435
In this paper, we present faster than real-time implementation of a class of dense stereo vision algorithms on a low-power massively parallel SIMD architecture, the CSX700. With two cores, each with 96 Processing Elements, this SIMD architecture provides a peak computation power of 96 GFLOPS while consuming only 9 Watts, making it an excellent candidate for embedded computing applications. Exploiting full features of this architecture, we have developed schemes for an efficient parallel implementation with minimum of overhead. For the sum of squared differences (SSD) algorithm and for VGA (640 × 480) images with disparity ranges of 16 and 32, we achieve a performance of 179 and 94 frames per second (fps), respectively. For the HDTV (1,280 × 720) images with disparity ranges of 16 and 32, we achieve a performance of 67 and 35 fps, respectively. We have also implemented more accurate, and hence more computationally expensive variants of the SSD, and for most cases, particularly for VGA images, we have achieved faster than real-time performance. Our results clearly demonstrate that, by developing careful parallelization schemes, the CSX architecture can provide excellent performance and flexibility for various embedded vision applications. 相似文献
28.
Amir Khakbaz Ali S. Nookabadi S. Nader Shetab-bushehri 《Networks and Spatial Economics》2013,13(1):43-66
Traffic congestion is one of the main problems in large cities for which several approaches have been proposed. Park-and-ride is one of the best approaches that can remove traffic from the traffic network. Park-and-ride facilities are an important part of urban mass transit systems, effectively extending the service area and attracting commuters and other people who may not otherwise have used mass transit. However, its efficiency depends on its location in the urban network. In this research, we focus on travel time of shortest paths instead of the distance criterion for computing network traffic and develop a model for finding the best location(s) for siting park-and-ride systems so as to minimize the network traffic. The model is formulated based on population points, potential sites for park-and-ride establishment, and several Central Business District (CBDs). Then we present a Genetic algorithm that has been proved to be efficient in solving large size problems. Finally, the proposed model is used to locate park-and-ride facilities in the city of Isfahan, Iran. 相似文献
29.
30.