全文获取类型
收费全文 | 7095篇 |
免费 | 622篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 59篇 |
综合类 | 5篇 |
化学工业 | 1904篇 |
金属工艺 | 79篇 |
机械仪表 | 208篇 |
建筑科学 | 276篇 |
矿业工程 | 15篇 |
能源动力 | 151篇 |
轻工业 | 1490篇 |
水利工程 | 72篇 |
石油天然气 | 16篇 |
无线电 | 454篇 |
一般工业技术 | 1170篇 |
冶金工业 | 323篇 |
原子能技术 | 16篇 |
自动化技术 | 1484篇 |
出版年
2024年 | 27篇 |
2023年 | 87篇 |
2022年 | 112篇 |
2021年 | 285篇 |
2020年 | 233篇 |
2019年 | 229篇 |
2018年 | 369篇 |
2017年 | 373篇 |
2016年 | 429篇 |
2015年 | 308篇 |
2014年 | 398篇 |
2013年 | 729篇 |
2012年 | 664篇 |
2011年 | 596篇 |
2010年 | 390篇 |
2009年 | 381篇 |
2008年 | 355篇 |
2007年 | 350篇 |
2006年 | 248篇 |
2005年 | 184篇 |
2004年 | 170篇 |
2003年 | 142篇 |
2002年 | 136篇 |
2001年 | 68篇 |
2000年 | 51篇 |
1999年 | 39篇 |
1998年 | 44篇 |
1997年 | 43篇 |
1996年 | 28篇 |
1995年 | 36篇 |
1994年 | 25篇 |
1993年 | 27篇 |
1992年 | 18篇 |
1991年 | 14篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1976年 | 4篇 |
1908年 | 2篇 |
1905年 | 2篇 |
1899年 | 2篇 |
排序方式: 共有7722条查询结果,搜索用时 15 毫秒
981.
982.
Cultivation of Solanum tuberosum in a former mining district for a safe human consumption integrating simulated digestion 下载免费PDF全文
983.
Bruno Esteves Luísa Cruz-Lopes Artur Figueirinha Luis Teixeira de Lemos José Ferreira Helena Pereira Idalina Domingos 《Holz als Roh- und Werkstoff》2017,75(6):903-909
Heavy metals adsorption with lignocellulosic materials has been heavily researched in the last years. Since heat activation has been used with good results to increase the adsorption capacity of some materials, heat-treated wood might be a better adsorbent. This hypothesis is the basis of the present study. The adsorption tests were made with powdered pine wood, heat-treated at 190–210?°C. All the heat-treated samples showed a significantly higher adsorption compared to untreated wood. The maximum adsorption was obtained at pH 3 for heat-treated wood at 210?°C. The kinetics of the adsorption process fitted a pseudo-second-order reaction (R2 0.990–0.996). Adsorption fitted well both the Langmuir and the Freundlich model, but the Freundlich model presented higher R2 (0.988–0.998). The qmax values estimated by the Langmuir plotting were in the range 15.6–19.4 mg/g and the n values from Freundlich isotherms between 1.87 and 2.39. Heat-treated wood was a better adsorption material than untreated wood for chromium adsorption. This can be a good application for the sawdust produced by the processing of heat-treated wood at primary and secondary wood processing mills or for the recycling of heat-treated wood at the end of product life. 相似文献
984.
Biochemical and Visual Changes in Cactus Stems (Opuntia ficus‐indica Mill.) Stored at 4, 12 and 26C 下载免费PDF全文
Lizette Liliana Rodríguez‐Verástegui Juliana Osorio‐Córdoba Fernando Díaz de León‐Sánchez Clara Pelayo‐Zaldívar David Manuel Díaz‐Pontones Elsa Bosquez‐Molina Guadalupe Judith Márquez‐Guzmán Héctor Bernardo Escalona‐Buendía José Ramón Verde‐Calvo Laura Josefina Pérez‐Flores 《Journal of Food Biochemistry》2015,39(4):449-461
985.
Discrimination of Euterpe oleracea Mart. (Açaí) and Euterpe edulis Mart. (Juçara) Intact Fruit Using Near‐Infrared (NIR) Spectroscopy and Linear Discriminant Analysis 下载免费PDF全文
986.
987.
988.
989.
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
990.
Effect of biodegradable film (lyophilised alga Fucus spiralis and sorbic acid) on quality properties of refrigerated megrim (Lepidorhombus whiffiagonis) 下载免费PDF全文
Bibiana García‐Soto José M. Miranda Ana Rodríguez‐Bernaldo de Quirós Raquel Sendón Ana V. Rodríguez‐Martínez Jorge Barros‐Velázquez Santiago P. Aubourg 《International Journal of Food Science & Technology》2015,50(8):1891-1900
The effect of replacing the on‐board currently employed polyethylene film by a novel type of environmentally friendly packaging was studied. For it, a polylactic acid (PLA) biodegradable film including lyophilised alga Fucus spiralis and sorbic acid was applied during megrim (Lepidorhombus whiffiagonis) refrigeration and its effect on fish quality loss was evaluated. Thus, sensory assessment showed that samples wrapped up with PLA film including 8% alga and 1% sorbic acid were still acceptable on day 11, while control fish specimens (kept under polyethylene film) were rejected at that time. Under such biodegradable film condition, a preservative effect was also implied according to chemical indices assessment related to microbial activity (trimethylamine–N) and lipid oxidation development (peroxide and fluorescent compounds formation); additionally, lower mean numbers for different microbiological groups (aerobes, Enterobacteriaceae and psychrotrophs) were detected. This result provides a promising replacement strategy to enhance refrigerated fish quality and reduce the waste material content. 相似文献