全文获取类型
收费全文 | 746篇 |
免费 | 69篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 16篇 |
综合类 | 2篇 |
化学工业 | 229篇 |
金属工艺 | 13篇 |
机械仪表 | 16篇 |
建筑科学 | 30篇 |
能源动力 | 23篇 |
轻工业 | 121篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 51篇 |
一般工业技术 | 100篇 |
冶金工业 | 38篇 |
原子能技术 | 6篇 |
自动化技术 | 168篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 27篇 |
2021年 | 46篇 |
2020年 | 25篇 |
2019年 | 35篇 |
2018年 | 42篇 |
2017年 | 37篇 |
2016年 | 45篇 |
2015年 | 32篇 |
2014年 | 47篇 |
2013年 | 58篇 |
2012年 | 42篇 |
2011年 | 58篇 |
2010年 | 39篇 |
2009年 | 46篇 |
2008年 | 24篇 |
2007年 | 28篇 |
2006年 | 25篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2003年 | 8篇 |
2002年 | 13篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有816条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
Ben‐Hur Ramos Ferreira Gonçalves Grazielly de Jesus Silva Silvania Farias Oliveira Pontes Rafael da Costa Ilhéu Fontan Antonio Silvio do Egito Sibelli Passini Barbosa Ferrão 《International Journal of Food Science & Technology》2016,51(7):1586-1593
Electrophoretic and chromatographic techniques were used to determine water‐soluble peptide profiles aiming to identify the adulteration of buffalo milk mozzarella cheese by the addition of cow's milk. Thus, cheeses were produced with contents of cow's milk varying from 0% to 100%, and the peptides extracted after production and after 20 days of refrigeration. Polyacrylamide gel electrophoresis under denaturing conditions in the presence of sodium dodecyl sulphate (SDS‐PAGE) identified a potential peptide marker of exclusively bovine origin with a size of about 21 kDa for the addition of cow's milk above 30%. Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) indicated the existence of two potential peptides present in higher concentrations in buffalo milk and one exclusive for cow's milk, the latter making it possible to estimate the addition of cow's milk to buffalo milk. Six commercial brands of buffalo mozzarella cheese were evaluated, and indications of adulteration found in four of them. 相似文献
35.
Jesus Israel Barraza-Fierro Bernardo Campillo-Illanes Ximing Li Homero Castaneda 《Metallurgical and Materials Transactions A》2014,45(9):3981-3994
Different thermomechanical treatments were applied to a high strength low carbon steel with a novel chemical composition. As a result, three different microstructures were produced with dissimilar mechanical and corrosion properties. Subsequently, a tempering heat treatment was applied to redistribute the phases in the steel. Microstructure A with 56 pct martensite and 32 pct bainite presented high strength but medium ductility; microstructure C with 95 pct ferrite and 3 pct martensite/austenite resulted in low strength and high ductility, and finally microstructure B with 98 pct bainite and 2 pct martensite/austenite resulted in high strength and ductility. Alternatively the corrosion behavior obtained by polarization curves was characterized in 0.1 M H2SO4, 3 M H2SO4, 3.5 wt pct NaCl, and NS4 solutions resulting in similar magnitudes, while the corrosion behavior acquired by electrochemical impedance spectroscopy had slightly differences in 3 M H2SO4. 相似文献
36.
37.
38.
Nucleation and Crystallization of New Glasses from Fly Ash Originating from Thermal Power Plants 总被引:1,自引:0,他引:1
Luisa Barbieri Isabella Lancellotti Tiziano Manfredini Gian Carlo Pellacani Jesus Ma. Rincòn Maximina Romero 《Journal of the American Ceramic Society》2001,84(8):1851-1858
The nucleation and crystallization kinetics of new glasses obtained by melting mixtures of a Spanish carbon fly ash with glass cullet and dolomite slag at 1500°C has been evaluated by a calculation method. These glasses, whose microstructure was examined by TEM carbon replica, were susceptible to controlled crystallization in the 800°–1100°C range. The resulting glass-ceramics developed acicular and branched wollastonite crystals or a network of dendritic pyroxene mixed with anorthite feldspar (SEM and EDX analysis). The time–temperature–transformation curves (processing of the XRD data) showed the crystallization kinetics and the critical cooling rate to be in the 12°–42°C/min range. 相似文献
39.
Francisco‐Javier Ruiz‐Rodriguez Jesus‐Casa Hernandez Francisco Jurado 《International Journal of Circuit Theory and Applications》2015,43(11):1541-1565
Probabilistic harmonic load flow (HLF) is currently enjoying renewed popularity. This is not surprising since in the near future, thousands of photovoltaic (PV) systems will be integrated into distribution systems. However, as yet, there is no model capable of explaining PV harmonic current behaviour in probabilistic HLF studies. To fill this gap, the harmonic modelling of PV systems proposed in this paper has three key points. First, it provides an effective model of the relationship between PV harmonic current emission and background harmonic voltages. Second, it statistically characterises PV harmonic currents (relative magnitude and phase angle) at different fundamental‐frequency current output intervals using historical time‐series data. In this statistical characterisation, the first fifth moments of each PV harmonic current are used to accurately approximate the raw probability density function (PDF) by means of the Legendre series. Finally, the third key point of this harmonic modelling is a method capable of determining the distribution functions of PV harmonic currents (absolute magnitude and phase angle), based on the statistical characterisation and a fundamental‐frequency probabilistic PV model. The numerical results obtained confirm the effectiveness of this PV model. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
40.
Wesley Pacheco Calixto A. Paulo Coimbra Jesus Carlos da Mota Marcel Wu Wander G. da Silva Bernardo Alvarenga Leonardo da Cunha Brito Aylton Jose Alves Elder Geraldo Domingues Daywes Pinheiro Neto 《International Journal of Numerical Modelling》2015,28(1):78-95
This work presents a genetic operator developed from mathematical methods of curve extrapolation applied in solving problems in geoelectrical prospection. This operator will assist the production of fitter individuals in the population of a genetic algorithm in which inherent patterns of the best individuals of each generation are recognized. The proposed operator in conjunction with a real‐coded genetic algorithm is compared to five alternative optimization techniques known and used in the application to problems in geoelectrical prospection. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献