全文获取类型
收费全文 | 885篇 |
免费 | 60篇 |
专业分类
电工技术 | 19篇 |
综合类 | 3篇 |
化学工业 | 264篇 |
金属工艺 | 12篇 |
机械仪表 | 21篇 |
建筑科学 | 20篇 |
矿业工程 | 3篇 |
能源动力 | 21篇 |
轻工业 | 65篇 |
水利工程 | 9篇 |
石油天然气 | 11篇 |
无线电 | 128篇 |
一般工业技术 | 171篇 |
冶金工业 | 65篇 |
原子能技术 | 5篇 |
自动化技术 | 128篇 |
出版年
2024年 | 4篇 |
2023年 | 26篇 |
2022年 | 35篇 |
2021年 | 46篇 |
2020年 | 34篇 |
2019年 | 52篇 |
2018年 | 70篇 |
2017年 | 42篇 |
2016年 | 46篇 |
2015年 | 36篇 |
2014年 | 49篇 |
2013年 | 76篇 |
2012年 | 51篇 |
2011年 | 72篇 |
2010年 | 40篇 |
2009年 | 40篇 |
2008年 | 26篇 |
2007年 | 20篇 |
2006年 | 24篇 |
2005年 | 11篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 11篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有945条查询结果,搜索用时 0 毫秒
941.
Proteolysis and antioxidant activity of peptic,tryptic and chymotryptic hydrolysates of cow,buffalo, goat and camel caseins 下载免费PDF全文
Fayza M Assem Mona A M Abd El‐Gawad Jihan M Kassem Mohamed H Abd El‐Salam 《International Journal of Dairy Technology》2018,71(1):236-242
Caseins of cow, buffalo, goat and camel milks were hydrolysed using pepsin, trypsin and chymotrypsin. The rate and degree of casein hydrolysis and the antioxidant activity (AA) of the casein hydrolysates (CH) were followed. Camel casein showed the highest rate and degree of hydrolysis with pepsin and trypsin, while cow casein was more rapidly hydrolysed with chymotrypsin than other caseins studied. The AA of all CH increased to a maximum after 24 h of hydrolysis. The AA of tryptic hydrolysates was higher (P < 0.002) than that of peptic hydrolysates. Camel CH exhibited higher AA than hydrolysates of other caseins. 相似文献
942.
Effects of Hot Water Treatments on Antioxidant Enzymatic System in Reducing Flesh Browning of Persimmon 总被引:1,自引:0,他引:1
Orang Khademi Alejandra Salvador Zabiollah Zamani Christina Besada 《Food and Bioprocess Technology》2013,6(11):3038-3046
The flesh browning that appears during commercialization period is the main postharvest disorder that is limiting the market of “Rojo Brillante” persimmon in the Mediterranean area. Previous studies have suggested that mechanical damage suffered by the fruit during packing line operations is the trigger of this alteration when fruit is previously subjected to the required deastringecy treatment. In the present work, the effect of hot water treatments (HWTs) on flesh browning incidence of Rojo Brillante persimmon has been investigated. For that, fruits submitted to the commercial deastringency treatment were hot water treated at 45 °C for 30 min or 50 °C for 20 min and then subjected to different intensity of mechanical damage in packing line. Fruit bathed at 25 °C for 25 min and fruit hand-packed acted as control treatments. Our results confirmed that mechanical damage during packing is a decisive factor in the incidence of flesh browning, and this alteration is found to increase the damage intensity. HWTs significantly alleviated flesh browning disorder by affecting the antioxidative system enzymes; the activity of catalase and ascorbate peroxidase was increased by HWTs while the activity of peroxidases was reduced. No changes were observed in polyphenol oxidase and phenylalanine ammonia lyase activity. Therefore, the application of HWTs may be a useful postharvest technology to reduce flesh browning of persimmon induced by packing line operations. 相似文献
943.
Mahshad Maghoumi Younes Mostofi Zabihollah Zamani Alireza Talaie Masoud Boojar Perla A. Gómez 《International Journal of Food Science & Technology》2014,49(1):153-159
The impact of heat treatment using hot air (HT 45 °C and 55 °C for 1 h) and two active modified atmosphere packaging (MAP) conditions of high oxygen atmosphere (HOA: 80 kPa O2, 20 kPa N2) and high CO2 atmosphere (HCA: 20 kPa CO2, 80 kPa N2), individually or combined, on the antioxidant capacity, polyphenols, vitamin C content, total anthocyanins, polyphenoloxydase (PPO) activity and shelf life of fresh‐cut (FC) pomegranate arils stored for 14 days at 4 °C was studied. The results indicate that HT 45 °C along with HOA inhibited PPO activity and prevented loss of antioxidant capacity, vitamin C and phenolic compounds in arils, in comparison with control and HT 55 °C. All treatments reduced the accumulation of anthocyanins, but HCA‐treated arils lost more anthocyanins besides having worse a* colour parameter values. No significant differences in titrable acidity (TA) and total soluble solids (TSS) were observed between treatments. The combination of HOA and HT 45 °C enhanced the benefits of applying each treatment separately and could be useful to improve and extend postharvest life of pomegranate FC arils. 相似文献
944.
The synthesis, some dyeing, and fastness properties of several new dispersed and acid dyes derived from the amino-benzotriazoles 1 & 3 and the aminobenzimidazoles 2a , 2b & 4 are described. The suitability of the amino derivatives 1 , 2a , 2b , 3 & 4 as bases for azoic dyeing has also been studied. Several interesting observations between the properties of some synthesised dyes and the corresponding benzene or naphthalene analogues are cited. 相似文献
945.
Nadia Sobhy Ibrahim Mona Hassan Mohamed Youssef Mahfouz Mohamed Hilmy Elnagdi 《Advanced Synthesis \u0026amp; Catalysis》1989,331(3):375-379
The reaction of diethyl monoiminomalonate with benzoylacetonitrile affords the ethyl 3-amino-4-cyanopentanoate derivative 1 a . Compound 1 a condensed with salicylaldehyde to yield the coumarin 5 and coupled with arenediazonium salts to yield the arenehydrazones 6a – c . Compounds 6a , b could be converted into the aminopyridazinium carboxylate 8a , b on treatment with aqueous sodium hydroxide. The reaction of 6a – c with hydrazine and phenyl hydrazine is reported. 相似文献