全文获取类型
收费全文 | 241篇 |
免费 | 26篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
综合类 | 2篇 |
化学工业 | 71篇 |
金属工艺 | 2篇 |
机械仪表 | 8篇 |
建筑科学 | 3篇 |
矿业工程 | 2篇 |
能源动力 | 4篇 |
轻工业 | 109篇 |
水利工程 | 5篇 |
石油天然气 | 24篇 |
无线电 | 2篇 |
一般工业技术 | 13篇 |
自动化技术 | 22篇 |
出版年
2024年 | 5篇 |
2023年 | 13篇 |
2022年 | 11篇 |
2021年 | 24篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 11篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 23篇 |
2013年 | 22篇 |
2012年 | 12篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 1篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 15 毫秒
41.
Hui Du Jie Wu Hui Li Pei-Xing Zhong Yan-Jun Xu Chong-Hui Li Kui-Xian Ji Liang-Sheng Wang 《Food chemistry》2013
Mugua, fruit of the genus Chaenomeles, is a valuable source of health food and Chinese medicine. To elucidate the bioactive compounds of five wild Chaenomeles species, extracts from fresh fruits were investigated by HPLC-DAD/ESI-MS/MS. Among the 24 polyphenol compounds obtained, 20 were flavan-3-ols (including catechin, epicatechin and procyanidin oligomers). The mean polymerisation degree (mDP) of procyanidins was examined by two acid-catalysed cleavage reactions; the mDP value was the highest in Chaenomeles sinensis and the lowest in Chaenomeles japonica. Total polyphenol content (TPC) reached 46.92 and 46.28 mg/g gallic acid equivalents (GAE) in Chaenomeles speciosa and Chaenomeles thibetica, respectively, although their main bioactive compounds were different (being epicatechin and procyanidin B2 in the former, and catechin and procyanidin B1 in the latter). These two species also exhibited equally strong free radical scavenging activities. Our results further showed that the antioxidant ability of Chaenomeles fruits was significantly correlated to their total polyphenol contents. Two triterpenes (oleanolic acid and ursolic acid) were the highest quantity in Chaenomeles cathayensis and C. thibetica, respectively. 相似文献
42.
采用商品蛋白酶Alcalase和Protamex对灵芝蛋白进行水解,并对灵芝蛋白水解前后抗氧化活性的变化进行了比较。结果表明:灵芝蛋白经过蛋白酶Alcalase和Protamex水解10 h后,氨基酸态氮含量从酶解前的0.15 mg/mL分别增长到0.61 mg/mL和0.54 mg/mL;Protamex酶解得到的游离氨基酸Lys、Val、Leu、Thr、Phe、Ala、Arg、Ile、Cys、His和Try含量较高,Alcalase酶解得到的游离氨基酸Ala、Val、Glu、Leu、Arg、Try和Thr含量较高;灵芝蛋白经过蛋白酶Alcalase和Protamex水解后,清除羟自由基的能力显著增强,水解前.OH自由基清除率为28.70%,水解后分别为39.10%和33.30%;还原力亦显著增强,水解前OD700值为0.21,水解后分别为0.35和0.34。 相似文献
43.
《Catalysis communications》2001,2(10):323-327
Hydrogenation of (E)-2-hexenal was carried out in a liquid phase using Co-based bimetallic catalysts (M–Co/Al2O3, M=Pd, Pt, Ru, Rh, Sn, Fe, or Cu). Pd–Co/Al2O3 showed the highest activity among the catalysts tested and catalyzed the hydrogenation of CC bond predominantly to produce hexanal and 1-hexanol. Pt–Co/Al2O3 was more active than monometallic Co/Al2O3 for the hydrogenation of CO bond. The excellent result, 92% selectivity to (E)-2-hexen-1-ol formation at 90% conversion, was obtained by the hydrogenation over Pt–Co/Al2O3 bimetallic catalyst. No improved activities were observed for the other bimetallic catalysts. 相似文献
44.
Zofia Lisiewska Jacek Słupski Radosława Skoczeń-Słupska Waldemar Kmiecik 《International Journal of Refrigeration》2009,32(2):272-278
The aim of the investigation was to evaluate the content of amino acids and the quality of protein in Brussels sprouts. The investigation included the raw material, cooked sample and two types of frozen product stored at ?20 °C for 12 months and then prepared for consumption. The frozen products investigated were obtained using the traditional method (blanching before freezing) and the modified method (cooking before freezing, then defrosting and heating in microwave oven after refrigerated storage) of the ready-to-eat type. Brussels sprouts, both fresh and prepared for consumption, were a good source of protein and amino acids. Proline and glutamic acid were dominating; leucine and tyrosine with phenylalanine were limiting amino acids. The product obtained by modified method contained 16% less amino acids in 16 g N than the raw material and 14% less than the raw material after cooking, and also 10% lower than that of the traditionally obtained product. 相似文献
45.
An advanced acoustic emission analysis method was used to study the dynamics and sequence of microfractures in uni-directional glass-fiber reinforced plastics (UD-GFRPs). UD-GFRPs (60 wt% fiber) with different interfacial qualities were prepared by adding a small amount (4 or 8 wt%) of paraffin wax into vinylester matrix without affecting much the mechanical properties of the matrix. The orientation dependence of both the P-wave velocity and attenuation were accurately measured by the laser ultrasonic method, and incorporated into the acoustic emission analysis of visco-elastic media. The analysis iteratively compares the acoustic emission signals (measured as out-of-plane displacements) with theoretical waveforms calculated assuming the time history and type of an acoustic emission source. The waveform simulation allows us to estimate the fracture dynamics and the sequence of the Mode-I fiber fracture (Type 1), Mode-I debonding (Type 2) and Mode-II disbonding (Type 3). The fiber fracture in UD-GFRPs without wax started at 0.1% strain. The initiation strain increased to 0.25 and 0.3% in the specimens with wax. The specimens with lower interfacial strength showed rapid succession of microfractures at higher stresses (above 100–200 MPa). Fracture dynamics showed distinct differences by wax addition. Using the present analysis method, we can determine quantitatively effects of interfacial quality on the microfracture processes and assess the integrity of UD-GFRPs. 相似文献
46.
47.
《Food Control》2014,35(2):714-718
Total 221 samples of milk and milk products were collected during winter (November 2011–February 2012) and 212 samples were collected during summer (May–August 2012) from central areas of Punjab, Pakistan. The samples were analyzed for the presence of aflatoxin M1 (AFM1) with a validated HPLC method equipped with florescence detector. The results revealed that from winter season almost 45% samples of milk and milk products were found to be contaminated with AFM1 i.e. 40% of raw milk, 51% of UHT milk, 37% of yogurt, 60% of butter and 43% of ice cream samples and 27, 24, 25, 34 and 17% of samples were found above the recommended limit for AFM1, respectively. However, from summer season 32% samples of milk and milk products were found to be contaminated i.e. 36% of raw milk, 31% of UHT milk, 29% of yogurt, 40% of butter and 24% of ice cream and 23, 23, 18, 20 and 5% of samples were found above the permissible limit for AFM1, respectively. The levels of contamination in winter milk and milk product samples were significantly higher (α ≤ 0.05) than in summer season. The occurrence of AFM1 in milk and milk products were higher, demanding to implement strict regulations and also urged the need for continuous monitoring of milk and milk products in order to minimize the health hazards. 相似文献
48.
49.
50.
黄秋葵属于锦葵科秋葵属的一年生草本开花植物,其绿色豆荚是一种具有很高营养价值和潜在益生功效的新型保健蔬菜,有很高的应用价值和开发潜力。从营养学角度,秋葵果荚是一种优质的蛋白质来源,含有多种矿质元素,具有增稠、稳定等一系列独特的食品加工性能,秋葵籽油具有较高的营养和保健价值。在功能特性方面,黄秋葵具有降血脂、抗疲劳、提高机体免疫力等作用。目前,黄秋葵保鲜主要采用真空预冷以及低温配合保鲜方式。黄秋葵产品主要集中在罐头、干制品、以及复合饮品等方面。本文主要介绍了黄秋葵的营养和功能特性、贮藏与保鲜、加工等进展,在综述黄秋葵营养与保健功能特性的基础上,对其产品的开发研究进行探讨,综述了黄秋葵研究现状,并展望了其发展前景,以期为黄秋葵产品的深度开发提供指导。 相似文献