全文获取类型
收费全文 | 584篇 |
免费 | 46篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 10篇 |
综合类 | 4篇 |
化学工业 | 105篇 |
金属工艺 | 13篇 |
机械仪表 | 39篇 |
建筑科学 | 5篇 |
能源动力 | 54篇 |
轻工业 | 81篇 |
水利工程 | 3篇 |
无线电 | 43篇 |
一般工业技术 | 147篇 |
冶金工业 | 26篇 |
原子能技术 | 1篇 |
自动化技术 | 103篇 |
出版年
2024年 | 6篇 |
2023年 | 14篇 |
2022年 | 67篇 |
2021年 | 81篇 |
2020年 | 40篇 |
2019年 | 49篇 |
2018年 | 48篇 |
2017年 | 42篇 |
2016年 | 39篇 |
2015年 | 21篇 |
2014年 | 28篇 |
2013年 | 31篇 |
2012年 | 21篇 |
2011年 | 26篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 15篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有634条查询结果,搜索用时 0 毫秒
41.
42.
Hassan Zaheer-ul- Munir Tariq Ahmad Naseeb Hashmi M. Ibad Ullah Ali Yasir Tahir Muhammad Bilal Hussain Abid Rehman Jalil ur Wattoo Abdul Ghafar Alrobei Hussein 《Journal of Superconductivity and Novel Magnetism》2021,34(12):3237-3242
Journal of Superconductivity and Novel Magnetism - Silver-substituted Fe–Ni nano invar alloy is a new and innovative field of research due to their interesting invar, magnetic and electrical... 相似文献
43.
Jingxing Wu Sailin Liu Yaser Rehman Taizhong Huang Jiachang Zhao Qinfen Gu Jianfeng Mao Zaiping Guo 《Advanced functional materials》2021,31(27):2010832
Sulfides are promising anode candidates because of their relatively large theoretical discharge/charge specific capacity and pretty small volume changes, but suffers from sluggish kinetics and structural instability upon cycling. Phase engineering can be designed to overcome the weakness of the electrochemical performance of sulfide anodes. By choosing nickel sulfides (α-NiS, β-NiS, and NiS2) supported by reduced graphene oxide (rGO) as model systems, it is demonstrated that the nickel sulfides with different crystal structures show different performances in both sodium-ion and potassium-ion batteries. In particular, the α-NiS/rGO display superior stable capacity (≈426 mAh g−1 for 500 cycles at 500 mA g−1) and exceptional rate capability (315 mAh g−1 at 2000 mA g−1). The combined density functional theory calculations and experimental studies reveal that the hexagonal structure is more conducive to ion absorption and conduction, a higher pseudocapacitive contribution, and higher mechanical ability to relieve the stress caused by the volume changes. Correspondingly, the phase engineered nickel sulfide coupled with the conducting rGO network synergistically boosts the electrochemical performance of batteries. This work sheds light on the use of phase engineering as an essential strategy for exploring materials with satisfactory electrochemical performance for sodium-ion and potassium-ion batteries. 相似文献
44.
Abbas Sohail Nasir Qassim Nouichi Douae Abdelsalam Mohamed Abu Talib Manar Abu Waraga Omnia Khan Atta ur Rehman 《Neural computing & applications》2021,33(21):14753-14769
Neural Computing and Applications - Security is one of the primary concerns when designing wireless networks. Along detecting user identity, it is also important to detect the devices at the... 相似文献
45.
46.
FT-Raman spectroscopy proves to be a powerful technique to study surface reactions on bioactive glasses and it eliminates the fluorescence of the organic phase of whole bone, thereby making it possible to compare the reaction layers formed on bioactive glasses with the mineral phase of bone. The spectrum of hydroxycarbonate apatite (HCA) developed on the bioactive glasses is closer to that of bone than synthetic hydroxyapatite (HA) and closely matches that of bone mineral obtained by deproteination of whole human femoral cortical bone. 相似文献
47.
Uncertainty modeling and robust minimax LQR control of multivariable nonlinear systems with application to hypersonic flight 总被引:1,自引:0,他引:1
For a class of multi‐input and multi‐output nonlinear uncertainty systems, a novel approach to design a nonlinear controller using minimax linear quadratic regulator (LQR) control is proposed. The proposed method combines a feedback linearization method with the robust minimax LQR approach in the presence of time‐varying uncertain parameters. The uncertainties, which are assumed to satisfy a certain integral quadratic constraint condition, do not necessarily satisfy a generalized matching condition. The procedure consists of feedback linearization of the nominal model and linearization of the remaining nonlinear uncertain terms with respect to each individual uncertainty at a local operating point. This two‐stage linearization process, followed by a robust minimax LQR control design, provides a robustly stable closed loop system. To demonstrate the effectiveness of the proposed approach, an application study is provided for a flight control problem of an air‐breathing hypersonic flight vehicle (AHFV), where the outputs to be controlled are the longitudinal velocity and altitude, and the control variables are the throttle setting and elevator deflection. The proposed method is used to derive a linearized uncertainty model for the longitudinal motion dynamics of the AHFV first, and then a robust minimax LQR controller is designed, which is based on this uncertainty model. The controller is synthesized considering seven uncertain aerodynamic and inertial parameters. The stability and performance of the synthesized controller is evaluated numerically via single scenario simulations for particular cruise conditions as well as a Monte‐Carlo type simulation based on numerous cases. It is observed that the control scheme proposed in this paper performs better, especially from the aspect of robustness to large ranges of uncertainties, than some controller design schemes previously published in the literature. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
48.
Jamil Ahmad Wajahat Ur Rehman Shaik Khadheer Basha Basheer Ahamed Kuppanna Chidambaram 《Polymer-Plastics Technology and Engineering》2019,58(4):366-383
Polyamide-b-ethylene (Pebax) is a promising material for membrane-based gas separation application with excellent CO2 capturing potential. Pebax is a rubbery elastomer which offers good mechanical support with its hard crystalline phase and excellent gas transport through its amorphous polyether phase. This review article includes recent advances in Pebax based membrane synthesis, solvent selection for membrane synthesis, compatible fillers with Pebax matrix and the improved gas separation performance of the prepared membranes. The literature review shows that Pebax based membranes are a good candidate for separation of CO2 from flue gases and can be used for commercial applications. 相似文献
49.
Silicon - Silicon (Si) is very effective in the amelioration of heavy metal (HM) stress in different crop plants. This investigation was conducted to assess the protective role of Si in modulating... 相似文献
50.
Sardar Muhammad Bilal Atta ur Rehman Khan Samee Ullah Khan Sajjad A. Madani Babar Nazir Mazliza Othman 《Wireless Personal Communications》2014,77(4):2497-2515
Over the last few years, vehicular ad hoc networks (VANETs) have gained popularity for their interesting applications. To make efficient routing decisions, VANET routing protocols require road traffic density information for which they use density estimation schemes. This paper presents a distributed mechanism for road vehicular density estimation that considers multiple road factors, such as road length and junctions. Extensive simulations are carried out to analyze the effectiveness of the proposed technique. Simulation results suggested that, the proposed technique is more accurate compared to the existing technique. Moreover, it facilitate VANET routing protocols to increase packet delivery ratio and reduce end-to-end delay. 相似文献