全文获取类型
收费全文 | 7790篇 |
免费 | 396篇 |
国内免费 | 51篇 |
专业分类
电工技术 | 214篇 |
综合类 | 20篇 |
化学工业 | 1659篇 |
金属工艺 | 162篇 |
机械仪表 | 258篇 |
建筑科学 | 238篇 |
矿业工程 | 8篇 |
能源动力 | 528篇 |
轻工业 | 782篇 |
水利工程 | 91篇 |
石油天然气 | 156篇 |
武器工业 | 4篇 |
无线电 | 957篇 |
一般工业技术 | 1368篇 |
冶金工业 | 455篇 |
原子能技术 | 80篇 |
自动化技术 | 1257篇 |
出版年
2024年 | 23篇 |
2023年 | 181篇 |
2022年 | 451篇 |
2021年 | 541篇 |
2020年 | 393篇 |
2019年 | 413篇 |
2018年 | 502篇 |
2017年 | 341篇 |
2016年 | 383篇 |
2015年 | 238篇 |
2014年 | 367篇 |
2013年 | 594篇 |
2012年 | 396篇 |
2011年 | 446篇 |
2010年 | 282篇 |
2009年 | 244篇 |
2008年 | 229篇 |
2007年 | 207篇 |
2006年 | 172篇 |
2005年 | 154篇 |
2004年 | 126篇 |
2003年 | 102篇 |
2002年 | 118篇 |
2001年 | 62篇 |
2000年 | 65篇 |
1999年 | 76篇 |
1998年 | 126篇 |
1997年 | 108篇 |
1996年 | 71篇 |
1995年 | 79篇 |
1994年 | 54篇 |
1993年 | 50篇 |
1992年 | 40篇 |
1991年 | 23篇 |
1990年 | 28篇 |
1989年 | 42篇 |
1988年 | 47篇 |
1987年 | 29篇 |
1986年 | 28篇 |
1985年 | 42篇 |
1984年 | 49篇 |
1983年 | 41篇 |
1982年 | 26篇 |
1981年 | 21篇 |
1980年 | 28篇 |
1979年 | 23篇 |
1978年 | 18篇 |
1977年 | 21篇 |
1976年 | 31篇 |
1974年 | 16篇 |
排序方式: 共有8237条查询结果,搜索用时 15 毫秒
51.
Kiani Azaz Ahmed Hafeez Yaser Imran Muhammad Ali Sadia 《The Journal of supercomputing》2021,77(8):8391-8432
The Journal of Supercomputing - Agile software development (ASD) and software product line (SPL) have shown significant benefits for software engineering processes and practices. Although both... 相似文献
52.
Asim Muhammad Nabeel Ghani Muhammad Usman Ibrahim Muhammad Ali Mahmood Waqar Dengel Andreas Ahmed Sheraz 《Neural computing & applications》2021,33(11):5437-5469
Neural Computing and Applications - In order to provide benchmark performance for Urdu text document classification, the contribution of this paper is manifold. First, it provides a publicly... 相似文献
53.
Khan Muhammad Hussain Saleem Zainab Ahmad Muhammad Sohaib Ahmed Ayaz Hamail Mazzara Manuel Raza Rana Aamir 《Neural computing & applications》2021,33(21):14507-14521
Neural Computing and Applications - Preserving red-chili quality is of utmost importance in which the authorities demand quality techniques to detect, classify, and prevent it from impurities. For... 相似文献
54.
Kader Md. Abdul Zamli Kamal Z. Ahmed Bestoun S. 《Neural computing & applications》2021,33(23):15933-15953
Neural Computing and Applications - Emperor Penguin Optimizer (EPO) is a recently developed metaheuristic algorithm to solve general optimization problems. The main strength of EPO is twofold.... 相似文献
55.
Elkenawy Ahmed El-Nagar Ahmad M. El-Bardini Mohammad El-Rabaie Nabila M. 《Neural computing & applications》2021,33(15):9221-9240
Neural Computing and Applications - This study introduces a neural network (NN) adaptive tracking controller-based reinforcement learning (RL) scheme for unknown nonlinear systems. First, an... 相似文献
56.
The grain boundary embrittlement in Cu-AI-Ni-phase alloys has been investigated. The study included both the bulk alloys and rapidly solidified ribbons. It was observed that the fracture characteristics and the phase transformations in rapidly solidified ribbons were similar to those in the bulk alloys. Various factors responsible for intergranular fracture were considered. It was found that intrinsic or extrinsic precipitates at the grain boundaries are not responsible for the embrittlement. It was further observed that the segregation of impurities does not occur at the grain boundaries and hence is not a factor contributing to the embrittlement. The intrinsic characteristics, however, appear to play an important role. These may include high elastic anisotropy, ordered structure and plastic incompatibility. Severe embrittlement in high-nickel alloys is associated with spinodal decomposition occurring in these alloys. The large grain size exhibited by these alloys is found not to be a significant factor contributing to the embrittlement. 相似文献
57.
A.c. susceptibility measurements were carried out on the disordered spinel system Co2–x
Zn
x
TiO4 (0<x<1) between 10 and 80 K. Our measurements show three peaks in the versus T curve for Co2TiO4 and CoZnTiO4 compounds. In both compounds two peaks are very close to each other, indicating that the Néel and semi-spin glass temperatures are very close. A third peak indicates the presence of the semi-spin glass to spin glass transition. In Co1.5Zn0.5TiO4 only one peak is observed which indicates spin glass ordering at 26 K. Furthermore, the A-site canting present in Co2TiO4 and CoZnTiO4 has a collinear and magnetic structure, indicating strong A-B coupling. X-ray analysis indicated that compounds of the system Co2ZnxTiO4 synthesized with cubic symmetry. From transport properties it was found that the activation energy and thermoelectric coefficient decrease with increasing concentration of Zn in the system. The mobility of the system calculated from infrared measurements is typically of the order of 10–9cm2V–1s–1. 相似文献
58.
Malgorzata Kloc Ahmed Uosef Jacek Z. Kubiak Rafik Mark Ghobrial 《International journal of molecular sciences》2021,22(1)
The development, progression, or stabilization of the atherosclerotic plaque depends on the pro-inflammatory and anti-inflammatory macrophages. The influx of the macrophages and the regulation of macrophage phenotype, inflammatory or anti-inflammatory, are controlled by the small GTPase RhoA and its downstream effectors. Therefore, macrophages and the components of the RhoA pathway are attractive targets for anti-atherosclerotic therapies, which would inhibit macrophage influx and inflammatory phenotype, maintain an anti-inflammatory environment, and promote tissue remodeling and repair. Here, we discuss the recent findings on the role of macrophages and RhoA pathway in the atherosclerotic plaque formation and resolution and the novel therapeutic approaches. 相似文献
59.
Silicon - In this study, inorganic-organic hybrid material consisting of tetraethyl orthosilicate (TEOS) and 3-methacryloxypropyl trimethoxysilane (MAPTMS) were prepared with sol-gel process and... 相似文献
60.
Amr Fouda Mohamed A. Awad Ahmed M. Eid Ebrahim Saied Mohammed G. Barghoth Mohammed F. Hamza Mohamed F. Awad Salah Abdelbary Saad El-Din Hassan 《International journal of molecular sciences》2021,22(10)
The discovery of eco-friendly, rapid, and cost-effective compounds to control diseases caused by microbes and insects are the main challenges. Herein, the magnesium oxide nanoparticles (MgO-NPs) are successfully fabricated by harnessing the metabolites secreted by Penicillium chrysogenum. The fabricated MgO-NPs were characterized using UV-Vis, XRD, TEM, DLS, EDX, FT-IR, and XPS analyses. Data showed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with sizes of 7–40 nm at a maximum wavelength of 250 nm. The EDX analysis confirms the presence of Mg and O ions as the main components with weight percentages of 13.62% and 7.76%, respectively. The activity of MgO-NPs as an antimicrobial agent was investigated against pathogens Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans, and exhibited zone of inhibitions of 12.0 ± 0.0, 12.7 ± 0.9, 23.3 ± 0.8, 17.7 ± 1.6, and 14.7 ± 0.6 mm respectively, at 200 µg mL−1. The activity is decreased by decreasing the MgO-NPs concentration. The biogenic MgO-NPs exhibit high efficacy against different larvae instar and pupa of Anopheles stephensi, with LC50 values of 12.5–15.5 ppm for I–IV larvae instar and 16.5 ppm for the pupa. Additionally, 5 mg/cm2 of MgO-NPs showed the highest protection percentages against adults of Anopheles stephensi, with values of 100% for 150 min and 67.6% ± 1.4% for 210 min. 相似文献