全文获取类型
收费全文 | 779篇 |
免费 | 40篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 14篇 |
综合类 | 1篇 |
化学工业 | 150篇 |
金属工艺 | 19篇 |
机械仪表 | 21篇 |
建筑科学 | 40篇 |
矿业工程 | 1篇 |
能源动力 | 70篇 |
轻工业 | 60篇 |
水利工程 | 8篇 |
石油天然气 | 6篇 |
无线电 | 97篇 |
一般工业技术 | 158篇 |
冶金工业 | 12篇 |
原子能技术 | 3篇 |
自动化技术 | 162篇 |
出版年
2024年 | 3篇 |
2023年 | 16篇 |
2022年 | 52篇 |
2021年 | 76篇 |
2020年 | 28篇 |
2019年 | 37篇 |
2018年 | 45篇 |
2017年 | 41篇 |
2016年 | 29篇 |
2015年 | 27篇 |
2014年 | 30篇 |
2013年 | 74篇 |
2012年 | 29篇 |
2011年 | 37篇 |
2010年 | 30篇 |
2009年 | 31篇 |
2008年 | 29篇 |
2007年 | 23篇 |
2006年 | 21篇 |
2005年 | 13篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有822条查询结果,搜索用时 15 毫秒
811.
Meshal Alzaid Fai Alsalh Rizwan Ahmed Malik Adnan Maqbool Noha Almoisheer N.M.A. Hadia W.S. Mohamed 《Ceramics International》2021,47(11):15710-15721
Piezoceramics with composition (1–z) [Bi0.5(Na0.84K0.16)0.5TiO3]0.96–0.04SrTiO3–zLiTaO3 (z = 0.00–0.030) were formulated by ordinary firing process following by rapid quenching treatment. Effect of LiTaO3 on the structural, electrical and energy-storage properties were analyzed. For the composition with molar ratio 0.025, room temperature large-field piezoelectric coefficient (Smax/Emax = d33*) of 885 pm/V at 3.6 kV/mm was recorded. Furthermore, for compositions z = 0.025 and 0.030, broad temperature stable dielectric constants and low losses from ~135 to 350 °C with a small variation of ± 15% was observed. Additionally, the energy density for z = 0.025 was ~0.60 J/cm3 in the broader temperature range of 75–125 °C, along with the energy-storage efficiency of greater than 70%. These observations suggest that the studied piezo-material compositions are promising for the ceramic actuators and capacitor applications. 相似文献
812.
Abdul Jabbar Ahsan Ahmad Muhammad Adnan Yasir Nawab Zafar Javed Muhammad Irfan 《应用聚合物科学杂志》2021,138(25):50683
In this study, high-performance polyethylene (HPPE) fiber-based needle punched nonwovens were interleaved in cross-plied woven carbon fabric/epoxy composite laminates to enhance their interlaminar and impact properties. The placement of needle punched nonwoven interleaves exhibited considerable enhancement in interlaminar shear strength (ILSS), impact damage tolerance, and compression after impact (CAI) strength of laminates as evidenced by higher interlaminar strength, less absorbed energy, higher elastic energy, reduced damage degree, reduced out-of-plane deformation, higher load-bearing capacity, and higher residual compressive strength as compared to control sample. In particular, the composite laminate with placement of interleaves in alternating sequence between carbon plies resulted in 205.76% increase in ILSS and 129, 103 and 85% increase in CAI at 10, 25, and 40 J impact energy, respectively. Moreover, damaged surface area and out-of-plane deformation reduced to 38.75% and 62.5%, respectively for the same specimen impacted at 40 J energy. These results suggest that the HPPE fiber-based needle punched nonwoven interleaving can be adopted as a simple and low-cost approach compared with other interleaving techniques, to enhance the resistance to delamination, impact performance, and damage tolerance of traditional structural laminates. 相似文献
813.
Sameer Adnan Ansari Mohammad Kazim Muhammad Areeb Khaliq Tahir Abdul Hussain Ratlamwala 《International Journal of Hydrogen Energy》2021,46(6):4724-4738
The study presented in this paper examines the operation of an integrated system. The study aims to present a method for utilizing geothermal energy in a way that minimizes energy waste and delivers maximum efficiency. A high-temperature geothermal well with a temperature of 300 °C is used as its primary source of energy. The system produces space heating, space cooling, electric power, hot water, freshwater and hydrogen as its outputs. These outputs utilize the excess energy that is obtained from the geothermal well, and by doing so, reduces waste, and increases the overall efficiency of the system. Among these outputs, freshwater and hydrogen are considered the most valuable, as water is an essential life resource and hydrogen is a prized form of energy. The novelty of this system compared to other geothermal sources is that it does not rely on any other source of input energy. It produces both freshwater, hydrogen and considerable amounts of electric power for commercial, industrial and/or residential use. Electric power is produced by two power cycles; the first one is a double flash steam cycle in the geothermal system and the second one is an organic Rankine cycle. 40% of the total electric power produced is sent to an electrolyzer to produce hydrogen gas. Freshwater is produced by single flash desalination. The system produces 22.1 MW of power as net electricity output. The system is assessed energetically and exergetically; it is found that the energy efficiency is 49.1%, while the exergy efficiency is 67.9%. Further parametric studies are carried out using Engineering Equation Solver (EES) to investigate the influence of operating conditions on the energy and exergy of the system. Moreover, major exergy destruction areas in the system are also identified. 相似文献
814.
Naeimeh Rajabalizadeh Mojarrad Bilal Iskandarani Adnan Taşdemir Alp Yürüm Selmiye Alkan Gürsel Begüm Yarar Kaplan 《International Journal of Hydrogen Energy》2021,46(25):13583-13593
In this study, novel nanofiber based-hybrid proton conducting membranes for polymer electrolyte membrane (PEM) fuel cells were fabricated via electrospinning method using sulfonated silica particles (S–SiO2) as a functional additive. Here, poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) was used as the carrier polymer during electrospinning step for the fabrication of PEM fuel cell membrane structure for the first time in literature. The effect of electrospinning conditions, i.e. namely, solvent, carrier polymer, electrospinning voltage, relative humidity, and flow rate on the uniformity of the resultant electrospun mats, and the average fiber diameter, respectively, were investigated in detail. Furthermore, electrospinning was conducted with poly(vinylidene fluoride) (PVDF) as the carrier polymer to compare with (P(VDF-TrFE)) as well. S–SiO2 particles were homogeneously distributed along the carrier polymer without any noticeable bead formation. After electrospinning, fiber mats were transformed into dense membranes via hot-pressing and subsequent Nafion® impregnation. After obtaining the densified membrane, proton conductivity, water uptake and mechanical strength of the hybrid membranes were examined and reported as well. Consequently, hybrid membrane with P(VDF-TrFE) carrier exhibited a superior proton conductivity (102 mS/cm) benchmarked with PVDF carrier polymer containing membrane (43 mS/cm) and solution casted Nafion® membrane (95 mS/cm) at the same conditions. 相似文献
815.
Adnan Midilli Haydar Kucuk Muhammed Emin Topal Ugur Akbulut Ibrahim Dincer 《International Journal of Hydrogen Energy》2021,46(50):25385-25412
This paper comparatively discusses hydrogen production options through coal gasification, including plasma methods, and evaluate them for practical applications. In this regard, it focuses on numerous aspects of hydrogen production from coal gasification, including (i) state of the art and comparative evaluation, (ii) environmental and economic dimensions, (iii) energetic and exergetic aspects, (iv) challenges, opportunities and future directions. Furthermore, this review paper outlines what differences it brings in and what contributions it makes to the current literature about such a significant domain of potential hydrogen production which can be used as clean fuel, energy carrier and feedstock. Accordingly, this comprehensive review offers some results as follows: (i) plasma gasification system produces higher amount of hydrogen from other gasification processes, (ii) less amounts of solid wastes (slag, ash, tar, etc.) are released during plasma gasification process compared to other gasification processes, and (iii) it is overall more sustainable Thus, plasma gasification is proposed as a potential option for hydrogen fuel production from coals and for practical application in energy sector. As a case study, some plasma gasifiers in the literature are analyzed in terms of the exergetic sustainability. Furthermore, the case study results show that the exergetic sustainability index decreases from 0.642 to 0.186, and the exergetic efficiency drops from 0.342 to 0.156, while the environmental impact factor increases from 1.556 to 5.372 with an increase of waste exergy ratio from 0.839 to 0.532, respectively. 相似文献
816.
Muflih A. Adnan Abdulhadi A. Al-Zahrani Tamanna I. Haque Shaikh A. Razzak Mohammad M. Hossain 《International Journal of Hydrogen Energy》2021,46(50):25500-25512
A new MnOx/Ce-γAl2O3 oxygen carrier is developed for liquid fuel based fluidized chemical looping combustion (CLC) process. The developed material serves both as a catalyst and as a source of solid phase oxygen for gasification/reforming of liquid fuel followed by the combustion of the gasified products. The support γAl2O3 is modified with cerium, improved thermal stability and minimized the interaction with the main active component MnOx. In order to validate the desired properties, the prepared MnOx/Ce-γAl2O3 samples are characterized using various physicochemical characterizations, including X-ray fluorescence (XRF), nitrogen adsorption, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), temperature programmed reduction (TPR), and temperature programmed desorption (TPD). TPR, TGA and XRD analysis confirm that the Ce modification improves the thermal stability of γAl2O3 and hinders the formation of difficult reducing manganese aluminate. TPR profiles show excellent reduction and re-oxidation performances of the Ce modified samples. Based on characterizations, a selected sample is further evaluated in a fluidized CREC Riser Simulator (CREC: Chemical Reactor Engineering Centre) using n-hexane as a liquid fuel surrogate. Under the studied reaction conditions (500–650 C; 10–45 s reaction time), CO2 and CO are the main combustion products. At 650 °C, approximately 92% n-hexane combustion and 60% of CO2 selectivity was achieved, which is very encouraging, given the complexity of the interaction of liquid fuel with the solid metal oxides. 相似文献
817.
Chen Junde Zeb Adnan Yang Shuangyuan Zhang Defu Nanehkaran Y. A. 《Neural computing & applications》2021,33(21):14413-14428
Neural Computing and Applications - Recent research has raised interest in applying image classification techniques to automatically identify the commodity label images for the business automation... 相似文献
818.
Adnan Harb 《Renewable Energy》2011,36(10):2641-2654
This paper presents a brief history of energy harvesting for low-power systems followed by a review of the state-of-the-art of energy harvesting techniques, power conversion, power management, and battery charging. The advances in energy harvesting from vibration, thermal, and RF sources are reviewed as well as power management techniques. Examples of discrete form implementation and integrated form implementation using microelectromechanical systems (MEMS) and CMOS microelectronic processes are also given. The comparison between the reviewed works concludes this paper. 相似文献
819.
Zhimin Chai Adnan Korkmaz Cihan Yilmaz Ahmed A. Busnaina 《Advanced materials (Deerfield Beach, Fla.)》2020,32(22):2000747
Printing of electronics has been receiving increasing attention from academia and industry over the recent years. However, commonly used printing techniques have limited resolution of micro- or sub-microscale. Here, a directed-assembly-based printing technique, interfacial convective assembly, is reported, which utilizes a substrate-heating-induced solutal Marangoni convective flow to drive particles toward patterned substrates and then uses van der Waals interactions as well as geometrical confinement to trap the particles in the pattern areas. The influence of various assembly parameters including type of mixing solvent, substrate temperature, particle concentration, and assembly time is investigated. The results show successful assembly of various nanoparticles in patterns of different shapes with a high resolution down to 25 nm. In addition, the assembly only takes a few minutes, which is two orders of magnitude faster than conventional convective assembly. Small-sized (diameter below 5 nm) nanoparticles tend to coalesce during the assembly process and form sintered structures. The fabricated silver nanorods show single-crystal structure with a low resistivity of 8.58 × 10−5 Ω cm. With high versatility, high resolution, and high throughput, the interfacial convective assembly opens remarkable opportunities for printing next generation nanoelectronics and sensors. 相似文献
820.