全文获取类型
收费全文 | 2103篇 |
免费 | 177篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 42篇 |
综合类 | 4篇 |
化学工业 | 504篇 |
金属工艺 | 78篇 |
机械仪表 | 126篇 |
建筑科学 | 44篇 |
矿业工程 | 1篇 |
能源动力 | 96篇 |
轻工业 | 190篇 |
水利工程 | 7篇 |
石油天然气 | 8篇 |
无线电 | 453篇 |
一般工业技术 | 474篇 |
冶金工业 | 68篇 |
原子能技术 | 15篇 |
自动化技术 | 179篇 |
出版年
2024年 | 6篇 |
2023年 | 40篇 |
2022年 | 69篇 |
2021年 | 97篇 |
2020年 | 50篇 |
2019年 | 62篇 |
2018年 | 87篇 |
2017年 | 85篇 |
2016年 | 104篇 |
2015年 | 87篇 |
2014年 | 90篇 |
2013年 | 167篇 |
2012年 | 169篇 |
2011年 | 206篇 |
2010年 | 136篇 |
2009年 | 129篇 |
2008年 | 115篇 |
2007年 | 72篇 |
2006年 | 58篇 |
2005年 | 56篇 |
2004年 | 55篇 |
2003年 | 60篇 |
2002年 | 46篇 |
2001年 | 34篇 |
2000年 | 38篇 |
1999年 | 29篇 |
1998年 | 39篇 |
1997年 | 23篇 |
1996年 | 22篇 |
1995年 | 16篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有2289条查询结果,搜索用时 0 毫秒
91.
92.
93.
Yon-Suk Kim Jin-Woo Hwang Si-Heung Sung Sun-Joo Park Yong-Tae Kim Eun-Kyung Kim Sang-Ho Moon Byong-Tae Jeon Pyo-Jam Park 《Food science and biotechnology》2015,24(2):735-741
Carvacrol is a monoterpenic phenol present in Thymus quinquecostatus Celak. The protective effects of carvacrol against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage were investigated in human Chang cells. Cells treated with carvacrol extracts promoted Chang cell survival and protection was associated with stabilization of the mitochondrial membrane potential (MMP), prevention of oxidative stress-triggered reactive oxygen species (ROS), and lipid peroxidation (MDA production). In addition, Annexin V/PI, observed using Hoechst staining, indicated that carvacrol inhibited t-BHP-induced cell damage and stimulated the antioxidant capability of Chang cells due to elevation of glutathione (GSH) levels, which were reduced by t-BHP treatment. Carvacrol prevented oxidative stress-induced Chang cell damage via suppression of ROS and MDA levels, and increased GSH levels. 相似文献
94.
Ko-Eun Hwang Tae-Kyung Kim Hynu-Wook Kim Nam-Su Oh Young-Boong Kim Ki-Hong Jeon Yun-Sang Choi 《Food science and biotechnology》2017,26(4):929-936
The effect of fermented red beet (FRB) on shelf-life of low-salt frankfurters stored for 4 weeks was investigated. The pH, volatile basic nitrogen (VBN), lightness, and yellowness of frankfurters decreased with increasing levels of FRB, whereas the redness of frankfurters increased with increasing levels of FRB. The VBN, thiobarbituric acid reactive substance values, total viable count, and redness of all treatments decreased with increasing period of refrigeration storage. The appearance, color, and juiciness scores of the control and treatments decreased with increasing period of refrigeration storage. However, there was no significant (p > 0.05) difference among the treatments except for the color of T3 (3.0% FRB) and juiciness of T4 (5.0% FRB). The flavor, tenderness, and overall acceptability scores of all the treatments decreased with increasing storage periods. These results demonstrated that FRB can be added to low-salt frankfurters to maintain their qualities and extend the shelf-life of refrigerated storage. 相似文献
95.
Ahn Eunyeong Lee Jimin Jeon Young-Hee Choi Sang-Won Kim Eunjung 《Food science and biotechnology》2017,26(6):1693-1702
Food Science and Biotechnology - Despite with accumulating evidences on the anti-diabetic effects of mulberry branch (MB), the major active component for the activity has not been known. Oral... 相似文献
96.
Anindita Mitra Yang-Fang Li Tobias G. Klämpfl Tetsuji Shimizu Jin Jeon Gregor E. Morfill Julia L. Zimmermann 《Food and Bioprocess Technology》2014,7(3):645-653
Sustaining the quality of seeds is a major task in attempting to supply nutrition to the growing world population. In this study, the seeds of Cicer arietinum were exposed to cold atmospheric plasma (CAP). A significant reduction of the natural microbiota attached to the seed surface was observed for increasing CAP treatment times—2 and 5 min were sufficient to achieve a 1 and 2 log reductions, respectively. Furthermore a 1 min CAP treatment showed a strongly improved seed germination (89.2 %), speed of germination (7.1?±?0.1 seeds/day), and increased seed vigor, beside a decrease in the mean germination time (2.7 days) compared with controls. The roughness profile of the seed cotyledon was altered significantly, only in case of longer treatment times from 5 min. These results suggest that CAP technology has the potentiality to reduce health risks associated with contaminated seeds, while improving food quality. 相似文献
97.
98.
99.
Royer RA Burgos WD Fisher AS Jeon BH Unz RF Dempsey BA 《Environmental science & technology》2002,36(13):2897-2904
The effects of natural organic matter (NOM), ferrozine, and AQDS (anthraquinone-2,6-disulfonate) on the reduction of hematite (alpha-Fe2O3) by Shewanella putrefaciens CN32 were studied. It has been proposed that NOM enhances the reduction of Fe(III) by means of electron shuttling or by Fe(II) complexation. Previously both mechanisms were studied separately using "functional analogues" (AQDS for electron shuttling and ferrozine for complexation) and are presently compared with seven different NOMs. AQDS enhanced hematite reduction within the first 24 h of incubation, and this had been ascribed to electron shuttling. Most of the NOMs enhanced hematite reduction after 1 day of incubation indicating that these materials could also serve as electron shuttles. The effect of ferrozine was linear with concentration, and all of the NOMs exhibited this behavior. Fe(II) complexation only enhanced hematite reduction after sufficient Fe(II) had accumulated in the system. Fe(II) complexation appeared to alleviate a suppression of the hematite reduction rate caused by accumulation of Fe(II) in the system. Addition of Fe(II) to the hematite suspension, prior to inoculation with CN32, significantly inhibited hematite reduction and greatly diminished the effects of all of the organic materials, although some enhancement was observed due to addition of anthroquinone-2,6-disulfonate. These results demonstrate that NOM can enhance iron reduction by electron shuttling and by complexation mechanisms. 相似文献
100.
ABSTRACT: The ability of 13 different strains of psychrotrophs to release free fatty acids in milk was evaluated by using GC analysis. The 13 strains could be categorized into 3 groups: Group 1 consisted of bacteria that grew well and released large quantities of free fatty acids, group 2 consisted of bacteria that grew well but released low amounts of free fatty acids, and group 3 consisted of bacteria that did not grow well nor released large quantities of fatty acids. In group 1, 3 strains were determined to be highly lipolytic, releasing short‐chain fatty acids in amounts greater than reported threshold values. Group 3 consisted of 2 strains, which did not grow well in heat‐treated milk, and the subsequent release of free fatty acids was minor during the 10‐d monitoring time. The other 8 strains tested showed no specific pattern of fatty acid release and quantities of short‐chain fatty acids were not large, despite the ability to grow to high numbers in the treated milk. This work indicates that the lipolytic activity of psychrotrophs common in raw milk is specific to the species and a general prediction of free fatty acid release may not be possible. 相似文献