全文获取类型
收费全文 | 392篇 |
免费 | 22篇 |
专业分类
化学工业 | 115篇 |
金属工艺 | 1篇 |
机械仪表 | 7篇 |
建筑科学 | 30篇 |
能源动力 | 3篇 |
轻工业 | 111篇 |
水利工程 | 3篇 |
石油天然气 | 3篇 |
无线电 | 16篇 |
一般工业技术 | 45篇 |
冶金工业 | 43篇 |
原子能技术 | 1篇 |
自动化技术 | 36篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 17篇 |
2021年 | 20篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 29篇 |
2012年 | 32篇 |
2011年 | 28篇 |
2010年 | 23篇 |
2009年 | 29篇 |
2008年 | 25篇 |
2007年 | 20篇 |
2006年 | 26篇 |
2005年 | 15篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有414条查询结果,搜索用时 15 毫秒
411.
Sarah Bernardis Bonna K. Newman Marisa Di Sabatino Sirine C. Fakra Mariana I. Bertoni David P. Fenning Rune B. Larsen Tonio Buonassisi 《Progress in Photovoltaics: Research and Applications》2012,20(2):217-225
Using synchrotron‐based analytical microprobe techniques, we determine micrometer‐scale elemental composition, spatial distribution, and oxidation state of impurities in raw feedstock materials used in the photovoltaic industry. Investigated Si‐bearing compounds are pegmatitic quartz, hydrothermal quartz, and quartzite. Micrometer‐scale clusters containing Fe, Ti, and/or Ca are frequently observed at structural defects in oxidized states and in bulk concentrations equivalent to inductively coupled plasma mass spectroscopy measurements. Investigated C‐bearing compounds are pine wood, pine charcoal, and eucalyptus charcoal. Clustered metals are observed only in the charcoal samples. Impurity clustering implies that industrial processing could be adapted to take advantage of this “natural gettering” phenomenon, expanding the usable range of raw feedstock materials to dirtier, cheaper, and more abundant ones, currently underexploited for solar‐grade silicon production. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
412.
The Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria, Acinetobacter baumannii, are pathogens responsible for millions of nosocomial infections worldwide. Due to the threat of bacteria evolving resistance to antibiotics, scientists are constantly looking for new classes of compounds to treat infectious diseases. The biphenolic analogs of honokiol that were most potent against oral bacteria had similar bioactivity against MRSA. However, all the compounds proved ineffective against A. baumannii. The inability to inhibit A. baumannii is due to the difficult-to-penetrate lipopolysaccharide-coated outer membrane that makes it challenging for antibiotics to enter Gram-negative bacteria. The C 2 scaffold was optimized from the inhibition of Gram-positive bacteria to broad-spectrum antibacterial compounds that inhibit the dangerous Gram-negative pathogen A. baumannii. 相似文献
413.
Forty-four analogs of honokiol, a compound with known antibacterial activity, especially with respect to oral bacteria, were synthesized to explore the structure-activity relationships against the ESKAPE pathogens. Compounds with high therapeutic indices (hemolysis20/MIC) were identified. In particular, ester-linked compounds that would be less than environmentally durable than biaryl ether antibacterials such as the broadly used triclosan were found to be active. MRSA mutants could be generated against some, but not all, of the highly active compounds. Based on gene sequencing results, membrane permeability, intracellular sodium, and intracellular pH assays revealed overlapping mechanisms of action. 相似文献
414.
Mathematical modeling of eggplant drying: Shrinkage effect 总被引:1,自引:0,他引:1
Antonio Brasiello Giuseppina Adiletta Paola Russo Silvestro Crescitelli Donatella Albanese Marisa Di Matteo 《Journal of food engineering》2013
In this paper two mathematical models with shrinkage effect describing eggplant drying are developed and discussed. The models are both modified diffusion equations and take differently into account changes of eggplant slice structure during drying. In the first model a diffusion coefficient variable with the water content is considered while in the second model a fictitious convective term is introduced. The two models are both suitable to describe the analyzed drying processes. Moreover, their equivalence is analytically demonstrated. Parameters values are estimated through a nonlinear regression procedure by comparison with the drying experiments carried out at different temperatures. Information about thickness evolution, derived from the models, are found to be in agreement with experimental data. 相似文献