全文获取类型
收费全文 | 487篇 |
免费 | 42篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 165篇 |
金属工艺 | 9篇 |
机械仪表 | 10篇 |
建筑科学 | 22篇 |
能源动力 | 20篇 |
轻工业 | 144篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 46篇 |
一般工业技术 | 50篇 |
冶金工业 | 13篇 |
原子能技术 | 1篇 |
自动化技术 | 42篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 32篇 |
2021年 | 29篇 |
2020年 | 25篇 |
2019年 | 27篇 |
2018年 | 23篇 |
2017年 | 30篇 |
2016年 | 31篇 |
2015年 | 15篇 |
2014年 | 33篇 |
2013年 | 53篇 |
2012年 | 47篇 |
2011年 | 35篇 |
2010年 | 29篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 0 毫秒
91.
92.
Jelena Vulić Jasna Čanadanović-Brunet Gordana Ćetković Vesna Tumbas Sonja Djilas Dragana Četojević-Simin Vladimir Čanadanović 《Journal of Functional Foods》2012,4(3):670-678
Beetroot (Beta vulgaris) pomace, processing by-product from food industry, was investigated in this work as a starting raw material. The contents of phenolics (1.87–11.98 mg GAE/g of dry weight) and betalains (0.75–3.75 mg betalains/g of dry weight) in the extracts were determinated spectrophotometrically. Some individual phenolic compounds, including ferulic, vanillic, p-hydroxybenzoic, caffeic and protocatehuic acids, were identified and quantified by HPLC. The antioxidative activity of beetroot extracts was tested using DPPH, hydroxyl and superoxide anion radicals by ESR spectroscopy. (0.05–0.108 mg/ml), (0.183–0.333 mg/ml), and (0.198–1.000 mg/ml) were calculated. The regression analysis produced moderate to high correlation coefficients between the scavenging activities and phenolics, and some individual phenolic compounds which indicated that beetroot pomace may be used as functional food ingredient. Cell growth effects were determined in MCF7 and MRC-5 cell lines, using SRB assay. IC50 values were in the range of 362.478–503.525 and 383–587.880 μg/ml in MRC-5 and MCF7, respectively. 相似文献
93.
Snežana Filip Branimir Pavlić Senka Vidović Jelena Vladić Zoran Zeković 《Food Analytical Methods》2017,10(7):2270-2280
Microwave-assisted extraction (MAE) was optimized by response surface methodology in order to enhance the extraction of polyphenols from basil (Ocimum basilicum L). Box–Behnken experimental design on three levels and three variables was used for optimization. Influence of ethanol concentration (50, 70, and 90%); microwave power (400, 600, and 800 W); and extraction time (15, 25, and 35 min) on each response were investigated. Experimental results were fitted to a second-order polynomial model, and multiple regression analysis and analysis of variance were used to evaluate model fitness and optimal conditions. Considering the maximum content of extracted total phenols, total flavonoids, and antioxidant activity, the optimal conditions for all investigated response were ethanol concentration of 50%, microwave power of 442 W, and extraction time of 15 min. Under the optimal conditions, obtained basil liquid extract contained 4.299 g gallic acid equivalents/100 g dry weight (DW) of total polyphenols, 0.849 g catechin equivalents/100 g DW of total flavonoids, and IC50 and EC50 values of 9.602 and 82.889 μg/mL, respectively. The development of simultaneous MAE procedure for extraction of total phenols, total flavonoids, and potential antioxidants from basil, represented valorization of basil as valuable source of bioactive compounds. 相似文献
94.
95.
Chiara E. Ghezzi Jelena Rnjak-Kovacina Anthony S. Weiss David L. Kaplan 《Israel journal of chemistry》2013,53(9-10):777-786
New multifunctional, degradable, polymeric biomaterial systems would provide versatile platforms to address cell and tissue needs in both in vitro and in vivo environments. While protein-based composites or alloys are the building blocks of biological organisms, similar systems have not been largely exploited, to date, to generate ad hoc biomaterials able to control and direct biological functions by recapitulating their inherent structural and mechanical complexities. Therefore, we have recently proposed silk tropoelastin material platforms that are able to conjugate a mechanically robust and durable protein, silk, to a highly flexible and biologically active protein, tropoelastin. This review focuses on the elucidation of the interactions between silk and tropoelastin to control the structure of the material its properties, and ultimately functions. In addition, an approach is provided for novel material designs to provide tools to control biological outcomes through surface roughness, elasticity, and net charge for neuronal and mesenchymal stem-cell-based tissue engineering. 相似文献
96.
Cyclic conjugation in corannulene and its benzo-derivatives is studied by means of the π-electron contents and the energy effects of individual rings, with particular attention to the structural effects influencing the magnitude of cyclic conjugation in the 5-membered ring. Two main general regularities were observed: (a) the PCP effect (6-membered rings connected by a single bond to the 5-membered ring increase in it the intensity of cyclic conjugation), and (b), the linear effect (6-membered rings separated from the 5-membered ring by another 6-membered ring, but not in PCP constellation, decrease the magnitude of cyclic conjugation in the 5-membered ring). 相似文献
97.
98.
Mihailović Mirjana Arambašić Jelena Uskoković Aleksandra Dinić Svetlana Grdović Nevena Marković Jelena Mujić Ibrahim Šijački D. Ana Poznanović Goran Vidaković Melita 《Journal of Functional Foods》2013,5(1):267-278
The mechanisms underlying the beneficial effect observed in diabetic rats after treatment with a commercially available β-glucan-enriched extract (BGEE) were examined. Multiple low-dose streptozotocin (STZ) diabetes was used (40 mg STZ/kg) as a model for type 1 diabetes. BGEE was administered daily (80 mg/kg) for 4 weeks, starting from the last day of the STZ treatment. In vitro and in vivo experiments suggest that significant free radical scavenging and antioxidant activities of BGEE were responsible for a systemic adjustment of the redox disturbance and reduction of DNA damage in the liver and kidney of diabetic rats. BGEE-treated diabetic rats also displayed increased Akt kinase activity and decreased pro-caspase-3 degradation, implying that BGEE mediates its beneficial effects through activation of the cellular pro-survival pathway. We conclude that β-glucan administration under diabetic conditions promotes a systemic improvement that can be expected to increase the organism’s resistance to the onset of diabetic complications. 相似文献
99.
Ljerka Prester Jelena Macan Veda Marija Varnai Tatjana Orct Jelena Vukušić Dubravka Kipčić 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(3):355-362
Whole Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) from the Croatian Adriatic were stored at 22 °C and changes in histamine, putrescine, tyramine and cadaverine levels were monitored in relation to bacterial endotoxin. After 12 h, histamine levels in sardine were above the legal limit of 50 mg kg?1, set by the US Food and Drug Administration, and an increase in putrescine content preceded the increase in histamine. After 24 h, histamine contents in mackerel and sardine reached 1090 ± 101 and 577 ± 275 mg kg?1, respectively, which exceeded the toxic threshold of 500 mg kg?1. At the same time, the putrescine content was also high in both fish (353–420 mg kg?1). The time-course of endotoxin production was similar in all fish species stored at 22 °C. A high correlation was found between endotoxin and histamine, and between endotoxin and putrescine in mackerel and sardine. On the other hand, high endotoxin levels in hake, after 24 h, were associated with the low histamine and putrescine content (40–60 mg kg?1). 相似文献
100.
Jelena Stojanović Miodrag Lazić Gordana Stojanović 《International Journal of Food Properties》2013,16(8):1861-1871
The content, composition, and radical scavenging capacity of phenolic compounds in wheat-chickpea (60:40, w/w) flour and dough were studied in this research. The content of phenolic compounds in wheat-chickpea dough was almost twice as high as in the flour from which the dough was made. The addition of chickpea flour to wheat flour contributed to the improved scavenging capacity of dough. The wheat-chickpea dough had a lower maximal achieved scavenging capacity than wheat-chickpea flour, but higher than that of the wheat dough. The quercetin, genkwanin, and apigenin glucosides could be considered as stable components during the mixing of the wheat-chickpea dough. The wheat-chickpea bread retained the radical scavenging capacity which the dough had. 相似文献