全文获取类型
收费全文 | 3855篇 |
免费 | 551篇 |
国内免费 | 104篇 |
专业分类
电工技术 | 33篇 |
综合类 | 222篇 |
化学工业 | 1123篇 |
金属工艺 | 55篇 |
机械仪表 | 17篇 |
建筑科学 | 245篇 |
矿业工程 | 41篇 |
能源动力 | 150篇 |
轻工业 | 2047篇 |
水利工程 | 70篇 |
石油天然气 | 269篇 |
武器工业 | 2篇 |
无线电 | 19篇 |
一般工业技术 | 114篇 |
冶金工业 | 44篇 |
原子能技术 | 21篇 |
自动化技术 | 38篇 |
出版年
2024年 | 32篇 |
2023年 | 103篇 |
2022年 | 187篇 |
2021年 | 273篇 |
2020年 | 218篇 |
2019年 | 230篇 |
2018年 | 189篇 |
2017年 | 187篇 |
2016年 | 203篇 |
2015年 | 172篇 |
2014年 | 207篇 |
2013年 | 252篇 |
2012年 | 254篇 |
2011年 | 256篇 |
2010年 | 199篇 |
2009年 | 167篇 |
2008年 | 134篇 |
2007年 | 184篇 |
2006年 | 167篇 |
2005年 | 152篇 |
2004年 | 113篇 |
2003年 | 92篇 |
2002年 | 123篇 |
2001年 | 59篇 |
2000年 | 47篇 |
1999年 | 37篇 |
1998年 | 19篇 |
1997年 | 30篇 |
1996年 | 28篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 31篇 |
1992年 | 21篇 |
1991年 | 20篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1977年 | 1篇 |
1951年 | 4篇 |
排序方式: 共有4510条查询结果,搜索用时 15 毫秒
1.
Anne Gabrielle Mathot Florence Postollec Ivan Leguerinel 《Comprehensive Reviews in Food Science and Food Safety》2021,20(1):840-862
Production and world consumption of spices are constantly increasing. Although the antimicrobial properties of some spices are well documented, their use in the agri-food industry is also responsible for microbial contamination and spoilage. Bacterial spores introduced by spices can withstand different preparation processes, particularly thermal treatments, leading to food alterations during storage. This review brings together data from the literature about the prevalence and concentrations of spore-forming bacteria in all commercially available spices. The sporeformers found in spices belong mainly to the genera Bacillus and Clostridium. Such contaminations are very common and sometimes reach high levels, as in pepper and turmeric. Bacillus licheniformis and Bacillus cereus are the most frequently detected species. Studying the harvesting, processing, and storage procedures for spices provides elements to explain why high prevalence and concentrations are observed. Spices are mostly produced in developing countries on small farms using traditional production methods. Spices become contaminated by bacterial spores in two main ways: by contact with soil during harvesting or drying, as for pepper, or by cross-contamination during the water-cooking step, as for turmeric. From these observations, we propose some recommendations. Different methods that can be used to eliminate bacterial spores from spices are presented indicating their efficiency and the limitations of their use. 相似文献
2.
Xuejie Li Yaqing Wen Jian Zhang Dongyun Ma Jie Zhang Yanxia An Xiaoyan Song Xiujuan Ren Weifeng Zhang 《International Journal of Food Science & Technology》2022,57(3):1544-1553
The effects of non-thermal plasma (NTP) on the physicochemical properties of wheat flour and the quality of fresh wet noodles ( FWN) were investigated. The results showed that NTP effectively decreased the total plate count (TPC), yeast and mould count (YMC) and Bacillus spp. in wheat flour. Wet gluten contents and the stability time reached the maximum when treated for 20 s. The viscosity of starch increased significantly after treatment due to the increased of damaged starch. The contents of secondary structure were altered to some extent, which was because that the ordered network structure of gluten protein broken. Furthermore, compared with the control, texture properties of FWN were enhanced significantly at 20 s, and the darkening rate of FWN was greatly inhibited due to the low polyphenol oxidase (PPO) activity. Consequently, the most suitable treatment was 500 W for 20 s, providing a basis for the application of NTP in flour products. 相似文献
3.
SPEEK/cSMM membrane for simultaneous electricity generation and wastewater treatment in microbial fuel cell 下载免费PDF全文
4.
Quality enhancement of the abundant under‐valued crustacean,lobster krill (Munida spp.), during its chilled storage 下载免费PDF全文
Bibiana García‐Soto José M. Miranda Jorge Barros‐Velázquez Santiago P. Aubourg 《International Journal of Food Science & Technology》2015,50(3):708-716
Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product. 相似文献
5.
以模拟生活污水为处理对象,三种不同填料为生物膜载体,运行 A、B、C三个SBBR,通过逐步降温(25、20、15、10、6和5℃)培养驯化处理低温污水的生物膜。运行251周期,三个反应器COD出水浓度均低于50 mg/L;B反应器对氨氮去除效果优于A和C。特别在低温5℃时,A、B和C三个反应器氨氮平均出水浓度分别为14.1、3.79和14.1 mg/L。高通量测序结果显示,5℃时,三个反应器中均以降解有机物的微生物为主;只有B反应器中驯化富集出了嗜冷硝化菌(Candidatus Nitrotoga);而其他有硝化作用的菌属在B反应器中的丰度也高于A和C反应器;不利于脱氮的类固氮菌(Elstera)在A和C反应器中丰度较高。此结果可从微生物角度解释三个反应器处理效果的差异性,表明B反应器处理低温污水有显著优势,其所用填料可结合低温菌进一步开发利用。 相似文献
6.
7.
8.
9.
10.
Qiuping Wang Bojan Šarkanj Jasna Jurasovic Yusuf Chisti Michael Sulyok Jiashun Gong Sarote Sirisansaneeyakul Draženka Komes 《International Journal of Food Science & Technology》2019,54(5):1541-1549
Theabrownins (TB) are polymeric phenolic compounds associated with the multiple bioactivities of Pu-erh tea, a post-fermented Chinese dark tea. High-TB instant Pu-erh tea was produced via a novel submerged fermentation (SF) using Aspergillus tubingensis and compared with samples produced commercially via the conventional solid-state fermentation (SSF). Viable microorganisms and microbial toxins, especially aflatoxins B1, G1, B2, G2, cyclopiazonic acid, fumonisins B1, B2, B3 and ochratoxin A, were below the detection limit in all samples. Fewer microbial metabolites were found in SF instant tea compared with the SSF teas. Based on an adult consuming 1 g of instant Pu-erh tea daily, the dietary intake of investigated elements was below the safe limits recommended by various authorities. Tasters viewed the instant tea infusions as very mild, smooth, mellow and full. This suggested that submerged fermentation using A. tubingensis offers a speedy and safe alternative to commercial production of instant Pu-erh tea. 相似文献