全文获取类型
收费全文 | 1338篇 |
免费 | 71篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 38篇 |
综合类 | 2篇 |
化学工业 | 427篇 |
金属工艺 | 10篇 |
机械仪表 | 31篇 |
建筑科学 | 45篇 |
能源动力 | 44篇 |
轻工业 | 155篇 |
水利工程 | 10篇 |
石油天然气 | 5篇 |
无线电 | 144篇 |
一般工业技术 | 212篇 |
冶金工业 | 63篇 |
原子能技术 | 8篇 |
自动化技术 | 217篇 |
出版年
2024年 | 5篇 |
2023年 | 27篇 |
2022年 | 59篇 |
2021年 | 95篇 |
2020年 | 46篇 |
2019年 | 48篇 |
2018年 | 50篇 |
2017年 | 37篇 |
2016年 | 50篇 |
2015年 | 35篇 |
2014年 | 81篇 |
2013年 | 84篇 |
2012年 | 88篇 |
2011年 | 103篇 |
2010年 | 82篇 |
2009年 | 58篇 |
2008年 | 51篇 |
2007年 | 60篇 |
2006年 | 58篇 |
2005年 | 35篇 |
2004年 | 30篇 |
2003年 | 30篇 |
2002年 | 20篇 |
2001年 | 21篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 19篇 |
1997年 | 21篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 4篇 |
1993年 | 10篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1411条查询结果,搜索用时 11 毫秒
21.
22.
Eleonora Di Campi Mauro Di Pasquale 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2020,37(5):753-762
ABSTRACTFatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated. 相似文献
23.
Mauro D. Santos Ivonne Delgadillo Jorge A. Saraiva 《International Journal of Food Science & Technology》2020,55(3):1171-1179
Hyperbaric storage (HS) was evaluated as a new food preservation methodology at room temperature (RT) for beef and pork meat, both minced and in pieces, and compared to refrigeration (RF) storage. The meat samples were stored at 50, 75 and 100 MPa and variable RT up to 60 days. HS at 75 and 100 MPa could not only inhibit microbial growth but also inactivate microorganisms. Regarding physicochemical analyses, an overall equal to better pH maintenance in HS samples was achieved, and similar colour differences between HS and RF were observed. Generally, similarities in moisture content and drip loss between HS (mostly 75 and 100 MPa) and RF were detected (tendency for lower values in the former and higher values in the latter for the higher pressure level). Protein solubility revealed a decrease of sarcoplasmic protein values during storage with a pressure level dependency in some samples. 相似文献
24.
25.
26.
27.
Valentina Paracchini Mauro Petrillo Antoon Lievens Dafni-Maria Kagkli Alexandre Angers-Loustau 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2019,36(1):1-14
Gadoids are a group of fish with historical importance in the fishing industry. The high demand for cod is one of the reasons why cod products are often mislabelled, and numerous observations have been made on the replacement of Atlantic cod (Gadus morhua) by cheaper species or its illegal capture in contravention of fish quotas. Fish species identification is traditionally based on morphological features, but this may be difficult in case of heat-treated or processed products, or where the species look similar, as in the Gadoid group. DNA-based approaches (using either nuclear or mitochondrial DNA) are most commonly used in this case, due to their high specificity and to the high resilience of the target molecules to food processing techniques. In this article, we identified, using an automated screening approach, novel barcode regions and their associated primers in the nuclear genome, to be used for the efficient identification of Gadoids. The barcode regions were tested on official and commercial samples, raw or mildly treated products, like frozen, or salted, as well as pre-cooked complex mixtures and processed samples, using next-generation sequencing (NGS) technique. The method proposed could complement existing fish identification strategies in establishing an efficient framework to detect and prevent frauds along the food chain. 相似文献
28.
29.
在意大利Aquafil公司与特伦托大学合作进行的科研工作的基础上,介绍和讨论了用于地毯和纺织品的新纤维的新的试验方法.此外,指出了各种创新的多种聚合物复合所得的结果.结果证实,由反应纺丝得到的多种聚合物的复合纤维,力学性质具有单值性. 相似文献
30.
In Vitro Starch Digestibility of Commercial Gluten‐Free Pasta: The Role of Ingredients and Origin 下载免费PDF全文
Alessandra Marti Parisa Abbasi Parizad Mauro Marengo Daniela Erba Maria Ambrogina Pagani Maria Cristina Casiraghi 《Journal of food science》2017,82(4):1012-1019
Gluten replacement in gluten‐free (GF) products presents major challenges for the food industry in terms of sensorial, technological and nutritional characteristics. The absence of gluten reportedly affects starch digestibility, thus increasing the postprandial glycaemic response. However, the role of ingredients and processing conditions has been addressed only seldom. We investigated the in vitro starch digestibility of 9 commercial GF products (5 Italian pasta and 4 Oriental noodles) differing in formulation and processing conditions. Content of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) were assessed and combined with information on starch pasting properties and on the overall protein organization. Oriental noodles presented higher relative levels of RS and RDS than Western‐style pasta, that often had SDS levels compatible with low rates of starch digestion. As regard formulation, presence of multiple ingredients seems to likely increase the RDS level, as did the different protein organization in the various samples. 相似文献