全文获取类型
收费全文 | 6438篇 |
免费 | 221篇 |
国内免费 | 26篇 |
专业分类
电工技术 | 82篇 |
综合类 | 22篇 |
化学工业 | 1371篇 |
金属工艺 | 255篇 |
机械仪表 | 151篇 |
建筑科学 | 95篇 |
矿业工程 | 21篇 |
能源动力 | 391篇 |
轻工业 | 389篇 |
水利工程 | 65篇 |
石油天然气 | 31篇 |
无线电 | 923篇 |
一般工业技术 | 1512篇 |
冶金工业 | 689篇 |
原子能技术 | 65篇 |
自动化技术 | 623篇 |
出版年
2024年 | 20篇 |
2023年 | 99篇 |
2022年 | 174篇 |
2021年 | 284篇 |
2020年 | 189篇 |
2019年 | 205篇 |
2018年 | 276篇 |
2017年 | 212篇 |
2016年 | 226篇 |
2015年 | 133篇 |
2014年 | 234篇 |
2013年 | 476篇 |
2012年 | 278篇 |
2011年 | 384篇 |
2010年 | 262篇 |
2009年 | 300篇 |
2008年 | 281篇 |
2007年 | 198篇 |
2006年 | 180篇 |
2005年 | 144篇 |
2004年 | 116篇 |
2003年 | 125篇 |
2002年 | 104篇 |
2001年 | 100篇 |
2000年 | 107篇 |
1999年 | 91篇 |
1998年 | 169篇 |
1997年 | 109篇 |
1996年 | 103篇 |
1995年 | 93篇 |
1994年 | 102篇 |
1993年 | 97篇 |
1992年 | 83篇 |
1991年 | 80篇 |
1990年 | 65篇 |
1989年 | 45篇 |
1988年 | 56篇 |
1987年 | 55篇 |
1986年 | 48篇 |
1985年 | 44篇 |
1984年 | 51篇 |
1983年 | 33篇 |
1982年 | 41篇 |
1981年 | 27篇 |
1980年 | 37篇 |
1979年 | 26篇 |
1978年 | 14篇 |
1977年 | 24篇 |
1976年 | 34篇 |
1973年 | 11篇 |
排序方式: 共有6685条查询结果,搜索用时 31 毫秒
1.
Prasad Ravi Kumar Madhu Santanoo Ramotra Prashant Edla Damodar Reddy 《Wireless Networks》2021,27(6):4111-4122
Wireless Networks - In Wireless Sensor Networks (WSNs), where power consumption is a huge concern, the improvement of the network’s lifetime is an area of constant study and innovation. The... 相似文献
2.
Gladson S. Chrisben Prasad P. Siva Manickam Bhaskar 《Analog Integrated Circuits and Signal Processing》2021,109(3):571-583
Analog Integrated Circuits and Signal Processing - As the 5G era beckons in the world of communication and information technology, there is a surge in demand for battery-operated, mobile wireless... 相似文献
3.
Wireless Personal Communications - Internet of Things (IoT) is one of the emerging technologies, which is widely used across the globe. As the idea of a smart city was founded, IoT has been... 相似文献
4.
Wireless Personal Communications - Internet of Things (IoT) offers complex networks of connected devices, which are used to serve in the real-time environment. Interestingly, Wireless Sensor... 相似文献
5.
Tuladhar Sanira Alsadoon Abeer Prasad P. W. C. Ali Akbas Ezaldeen Alrubaie Ahmad 《Multimedia Tools and Applications》2022,81(17):23845-23865
Multimedia Tools and Applications - Gastrointestinal stromal tumor is one of the critical tumors that doctors do not suggest to get frequent endoscopy, so there is a need for a diagnosis system... 相似文献
6.
In the present work, two types of shear thickening fluids have been synthesized by using neat and aminosilane functionalized silica nanoparticles and their viscosity curves have been obtained by the rheometer. Based on the values of peak viscosity of synthesized shear thickening fluids, the surface functionalized nanosilica based shear thickening fluid has been chosen as a best candidate due to the high viscosity for impregnation into the neat Kevlar of different layers viz. four (04) and eight (08) layers for velocity impact study. The experimental investigations reveal high energy absorption of shear thickening fluid impregnated Kevlar as compared to the neat Kevlar. The maximum energy absorption 62 J is achieved corresponding to the initial velocity 154 m∙s−1 for 08 layers shear thickening fluid impregnated Kevlar specimen. The data have also been analytically determined and validated with the experimental data. The experimental data have good agreement with the analytical data within the accuracy of around 15 to 20%. The present findings can have significant inferences towards the fabrication of shear thickening fluids using nanomaterials for numerous applications such as soft armors, dampers, nanofinishing and so forth. 相似文献
7.
8.
Dhirendra Kumar Mishra Gopal Pugazhenthi Tamal Banerjee 《International Journal of Hydrogen Energy》2021,46(29):15773-15779
The current work explores the usage of novel synthesized Deep Eutectic Solvent (DES) as a catalyst cum solvent media for the thermal dehydrogenation of chemical hydrides, namely Ammonia Borane (AB) and Ethylene diamine bisborane (EDAB). In the first instance, the quantum chemistry based COSMO-SAC (COnductor like Screening MOdel Segment Activity Coefficient) model was used for the selection of the pertinent solvent. 1-Butyl-3-methylimidazolium methanesulfonate: Imidazole ([BMIM][MeSO3]:[Im]) turned out to be an ideal eutectic mixture with the highest predicted solubility with amine boranes. The DES was synthesized by combining the Hydrogen Bond Acceptor (HBA), namely 1-Butyl-3-methylimidazolium methanesulfonate and Imidazole as Hydrogen Bond Donor (HBD) at a molar ratio of 1:2 and T = 70 °C. The formation of DES was confirmed by recording the NMR spectra. Further, the thermal dehydrogenation study was performed at a vacuum of 4 × 10?2 mbar (gauge pressure) of AB/DES and EDAB/DES systems at 105 °C, where a hydrogen equivalent of 1.40 and 2.55 was produced, respectively. The residual samples were further analyzed through 1H NMR analysis for the reaction mechanism and to confirm the role of Ionic Liquid-based DES as catalyst cum solvent media. 相似文献
9.
Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few... 相似文献
10.
ABSTRACTA mathematical model has been developed by coupling genetic algorithm (GA) with heat and material balance equations to estimate rate parameters and solid-phase evolution related to the reduction of iron ore-coal composite pellets in a multi-layer bed Rotary hearth Furnace (RHF). The present process involves treating iron ore-coal composite pellets in a crucible over the hearth in RHF. The various solid phases evolved at the end of the process are estimated experimentally, and are used in conjunction with the model to estimate rate parameters. The predicted apparent activation energy for the wustite reduction step is found to be lower than those of the reduction of higher oxides. The thermal efficiency is found to decrease significantly with an increase in the carbon content of the pellet. Thermal efficiency was also found to increase mildly up to three layers. Multilayer bed remains as a potential design parameter to increase thermal efficiency. 相似文献