首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   280篇
  免费   42篇
电工技术   1篇
化学工业   88篇
金属工艺   3篇
机械仪表   21篇
建筑科学   5篇
能源动力   6篇
轻工业   142篇
石油天然气   8篇
一般工业技术   33篇
冶金工业   3篇
自动化技术   12篇
  2024年   3篇
  2023年   10篇
  2022年   13篇
  2021年   25篇
  2020年   13篇
  2019年   16篇
  2018年   21篇
  2017年   22篇
  2016年   16篇
  2015年   21篇
  2014年   22篇
  2013年   21篇
  2012年   29篇
  2011年   23篇
  2010年   10篇
  2009年   12篇
  2008年   11篇
  2007年   11篇
  2006年   9篇
  2005年   2篇
  2004年   4篇
  2003年   3篇
  2002年   3篇
  1996年   1篇
  1991年   1篇
排序方式: 共有322条查询结果,搜索用时 15 毫秒
91.
92.
The effectiveness of grape extracts as food ingredient has been tested in various systems. The objective of this study was to evaluate the efficiency of four concentrations of residues of the wine industry in delaying lipid oxidation in processed chicken meat stored under refrigeration. The development of oxidation during the 14‐day storage was evaluated through the thiobarbituric acid reactive substances method (TBAS). The analyses of phenolic compounds and antioxidant activity were performed in grape residue extracts through DPPH (1,1‐difenil‐2‐picrilidrazil) method, lipid peroxidation inhibition and Rancimat. The profile of polyphenols was determined using reversed‐phase high‐performance liquid chromatography. Isabel grape extract (IGE) and Niagara grape extract (NGE) showed significant content of phenolic compounds. NGE and IGE had high antioxidant activity. The addition of grape extracts significantly increased the oxidative stability of processed and cooked chicken meat during the storage time. The extracts from both grape varieties when applied in concentrations of 40 and 60 mg of GAE, presented results similar to that of Butyl hydroxy toluene (BHT).  相似文献   
93.
Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.  相似文献   
94.
The ethanol extract from Vernonia polyanthes leaves (EEVP) was investigated for antinociceptive and anti-inflammatory effects at the doses (p.o.) of 100, 200 and 400 mg/kg in animal models. The extract reduced the number of abdominal contortions by 16.75% and 31.44% at a dose of 200 and 400 mg/kg, respectively. The results obtained showed that EEVP exerted a significant antinociceptive effect in the two phases of formalin. The EEVP increased the reaction time on a hot plate at the doses of 100, 200 and 400 mg/kg after 90 min of treatment. The paw edema was reduced by EEVP at the doses of 100, 200 and 400 mg/kg after 4 h of application of carrageenan. Doses of 200 and 400 mg/kg, administered 4 h before the carrageenan injection, significantly reduced the exudate volume (29.25 and 45.74%, respectively) and leukocyte migration (18.19 and 27.95%, respectively). These results suggest that V. polyanthes can be an active source of substances with antinociceptive and anti-inflammatory activities.  相似文献   
95.
In a previous work, succinylated sugarcane bagasse (SCB 2) was prepared from sugarcane bagasse (B) using succinic anhydride as modifying agent. In this work the adsorption of cationic dyes onto SCB 2 from aqueous solutions was investigated. Methylene blue, MB, and gentian violet, GV, were selected as adsorbates. The capacity of SCB 2 to adsorb MB and GV from aqueous single dye solutions was evaluated at different contact times, pH, and initial adsorbent concentration. According to the obtained results, the adsorption processes could be described by the pseudo-second-order kinetic model. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities for MB and GV onto SCB 2 were found to be 478.5 and 1273.2 mg/g, respectively.  相似文献   
96.
Waste cooking oils (WCO) can be used as feedstock for biodiesel (fatty acid ethyl or methyl esters—FAEE or FAME) production. Their usual high acidity, high moisture, and low stability can impair the reaction yield and generate a low-quality biodiesel. Here, we performed liquid–liquid washings using WCO and ethanol-based solvents with the goal of generating oil-rich miscella as FAEE feedstocks with a higher quality than WCO. Three different solvents were evaluated: 99% ethanol, 95% ethanol, and the soybean oil extraction ethanolic phase (SEP), a by-product with immense unexplored antioxidant potential obtained by extracting soybean oil using ethanol. Washings were performed in a 1000 mL flat-bottom flask at 78.1 °C, using a 1:2 (w/v) oil/solvent ratio, under magnetic stirring (1200 rpm) for 10 min. Ethyl esters were prepared via homogeneous alkali transesterification using WCO and oil-rich miscella as feedstocks. Treatments reduced the acid value by 40–61% and the peroxide value by 15–50%. Improvements in feedstock quality generated 24–54% higher biodiesel yields. The oil-rich phase produced with SEP was 15% more resistant to oxidation than WCO. This was attributed to the transference of isoflavones from the SEP. However, biodiesel from treated samples presented equal or lower oxidative stability than FAEE from WCO. High-performance liquid chromatography (HPLC) analysis showed that no isoflavones remained in biodiesel after purification. Pretreatment of WCO with ethanol-based extracts such as the SEP has great potential to improve WCO quality for biodiesel production as it can be a source of plant-based antioxidants.  相似文献   
97.
98.
Methodi Ordinatio is a methodology used to accomplish systematic literature reviews, to build bibliographical portfolios, and to map the state of the art of a research theme. It is composed of nine phases. The 7th phase, named InOrdinatio, applies an equation that orders the papers according to its scientific relevance. The equation applies the alpha (α) element, which can vary from 0 to 10 depending on the research need of currentness and according to the researcher’s perception for its variation. Therefore, the aim of this paper is to test and analyse the variations of the alpha (α) values in the equation InOrdinatio and its influence in the qualification of the items that composes a portfolio. In order to reach this purpose, a practical application was performed and a bibliographic portfolio on the theme Horizontal Business Networks and Trust was built. Using the data from the bibliographic portfolio, the alpha values from 0 to 10 were applied and their influence on the final qualification of the articles was analysed. As a complementary objective, the areas where the methodology was successfully applied until now are also identified. The results show that the methodology is coherent, reproducible and useful to sort the most relevant articles in accordance with what is internationally recognized as valid scientific criteria: the impact factor, year of publication, and number of citations.  相似文献   
99.
Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (°Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1, ω9) and 37.10% and 37.63% (C18:2, ω6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 μmol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples.  相似文献   
100.
This paper aims to study discontinuous deep frying of potatoes, milanesas (breaded bovine Semimembranosus muscle) and churros (flour, water, milk, lemon and salt) in soybean oil, sunflower oil and partially hydrogenated fats, monitored by conventional and unconventional methods. With the exception of partially hydrogenated fat after 80.5 h of deep-frying churros, all the oils exceeded 25% of total polar compounds (TPC) and the content of polymeric and dimerized triacylglycerols were higher than 10%, prevailing thermal alterations. For none of the samples the percentage of free fatty acids exceeded 2% of oleic acid. The losses of tocopherols during frying reached 76.0%. Little significant alterations occurred in the fatty acids composition, iodine index calculated, saponification index and formation of trans isomers after frying. The rapid tests used to determine TPC, malondialdehyde and alkenals have proved to be viable alternatives to monitor the quality of frying oils.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号