全文获取类型
收费全文 | 285篇 |
免费 | 19篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 85篇 |
金属工艺 | 11篇 |
机械仪表 | 10篇 |
建筑科学 | 11篇 |
能源动力 | 18篇 |
轻工业 | 58篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 33篇 |
冶金工业 | 12篇 |
自动化技术 | 54篇 |
出版年
2024年 | 3篇 |
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 25篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 15 毫秒
1.
Acar Seda Bekin Tasdelen Mehmet Atilla Karaagac Bagdagul 《Iranian Polymer Journal》2021,30(7):697-705
Iranian Polymer Journal - The addition of methacrylate-functional polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles to styrene-butadiene rubber (SBR) composites was evaluated in terms of... 相似文献
2.
Neural Computing and Applications - In this paper, we consider a system of nonlinear delay integro-differential equations with convolution kernels, which arises in biology. This problem... 相似文献
3.
Martti Heinonen Miltiadis Anagnostou Stephanie Bell Mark Stevens Robert Benyon Reidun Anita Bergerud Jovan Bojkovski Rien Bosma Jan Nielsen Norbert B?se Plunkett Cromwell Aliye Kartal Dogan Seda Aytekin Ali Uytun Vito Fernicola Krzysztof Flakiewicz Bertrand Blanquart Domen Hudoklin Per Jacobson Anders Kentved Isabel Lóio George Mamontov Alexandra Masarykova Helmut Mitter Regina Mnguni Jan Otych Anton Steiner Nagyné Szilágyi Zsófia Davor Zvizdic 《International Journal of Thermophysics》2012,33(8-9):1422-1437
In the field of humidity quantities, the first CIPM key comparison, CCT-K6 is at its end. The corresponding European regional key comparison, EUROMET.T-K6, was completed in early 2008, about 4?years after the starting initial measurements in the project. In total, 24 NMIs from different countries took part in the comparison. This number includes 22 EURAMET countries, and Russia and South Africa. The comparison covered the dew-point temperature range from ?50?°C to +20?°C. It was carried out in three parallel loops, each with two chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. It is shown that the standard uncertainty due to the long-term instability was smaller than 0.008?°C in all loops. The standard uncertainties due to links between the loops were found to be smaller than 0.025?°C at ?50?°C and 0.010?°C elsewhere. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from the EURAMET comparison reference values (ERV). Taking into account 16 different primary dew-point realizations and 8 secondary realizations, the results demonstrate the equivalence of a large number of laboratories at an uncertainty level that is better than achieved in other multilateral comparisons so far in the humidity field. 相似文献
4.
This paper reports the charge transport mechanism of polythiophene (PT) matrix composites having various concentrations of copper(II) acetylacetonate. Characterization and structural analyses of the samples were carried out via Fourier transform infrared spectroscopy, atomic absorption spectroscopy, differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy (SEM). The alternating current electrical properties were investigated as a function of temperature. The change of free energy of adsorption calculated from the Langmuir adsorption isotherm showed that metal ions were electrostatically adsorbed onto polymer chains. Significant morphological changes were observed from SEM images of PT depending on doping process which in turn affected the thermal degradation of PT. The charge transport mechanism determined from a power law showed that there was one frequency‐dependent conductivity region for PT, while there were two regions for the composites in contrast to studies reported in the literature. © 2013 Society of Chemical Industry 相似文献
5.
6.
Healthcare facilities are often complex and overwhelming for visitors, and wayfinding in healthcare facilities can be challenging. As there is an increasing number of global citizens who travel to seek medical care in another country, it is critical to make wayfinding easy for visitors who are not familiar with the language in a foreign country. Among many wayfinding aids, symbols are helpful for those visitors who have limited ability to understand written language. This study tested universal healthcare symbols in the United States, South Korea, and Turkey to compare the comprehension of symbols cross-country and identify predictors of the correct comprehension. To explore statistically significant relationships between symbol comprehension and countries, Pearson's Chi-square tests, logistic regression, and ANOVA were conducted. The test results showed that ten symbols among 14 tested have significant relationship with countries. Results of this study demonstrate that symbol comprehension can be varied significantly in different countries. 相似文献
7.
8.
Seda Karaboğa 《International Journal of Hydrogen Energy》2021,46(34):17763-17775
It reports the preparation and characterization of tungsten(VI) oxide supported rhodium(0) nanoparticles (Rh0/WO3 NPs) being used as catalysts in releasing H2 from dimethylamine borane (DMAB). The reducible nature of WO3 plays a significant role in the catalytic efficiency of rhodium(0) nanoparticles in the dehydrogenation of DMAB. The Rh0/WO3 NPs were in-situ generated from the reduction of Rh2+ ions on the surface of WO3 during the catalytic dehydrogenation of dimethylamine borane in toluene and isolated from the reaction solution after the dehydrogenation to be characterized by using SEM, TEM, XPS, ATR-IR and XRD. The results reveal the formation of Rh0 NPs with a mean particle size of 1.92 ± 0.34 nm dispersed on the surface of tungsten(VI) oxide. Rh0/WO3 NPs are found to be very active catalyst releasing 1.0 equiv. H2 per mole of dimethylamine borane under ambient conditions. Among the various WO3 supported Rh0 NPs with different metal loadings, the sample with 0.1% wt. Rh provide the record catalytic activity (TOF = 2816 h?1) which is one of the highest value ever reported for rhodium-based catalysts in H2 generation from DMAB at 60.0 ± 0.5 °C. Rh0/WO3 NPs were also reusable catalyst in dehydrogenation of DMAB retaining 55% of their initial catalytic activity in the 3rd run of the dehydrogenation reaction. Control experiments were performed at various catalyst concentrations and temperatures to investigate the kinetics of dehydrogenation and to calculate the activation parameters for the reaction. 相似文献
9.
10.
The aim of the present work was to determine the applicability of raw and modified brown macroalga Cystoseira sp. as a biosorbent material for the sorption of uranium ions from aqueous solutions. Equilibrium of uranium biosorption was analyzed under isotherm models and thermodynamic parameters of the process. Recovery of uranium from acidic mine wastewater was also applied. The mechanism of biosorption was discussed considering experimental data and theoretical models. The bioremoval efficiency of modified biomass was higher than raw Cystoseira sp. and the theoretical biosorption capacity of modified biosorbent was calculated to be 468.01 mg U/g. 相似文献