全文获取类型
收费全文 | 323篇 |
免费 | 33篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 109篇 |
机械仪表 | 2篇 |
建筑科学 | 30篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 74篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 14篇 |
一般工业技术 | 54篇 |
冶金工业 | 5篇 |
原子能技术 | 1篇 |
自动化技术 | 53篇 |
出版年
2023年 | 3篇 |
2022年 | 24篇 |
2021年 | 26篇 |
2020年 | 16篇 |
2019年 | 21篇 |
2018年 | 11篇 |
2017年 | 22篇 |
2016年 | 22篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 21篇 |
2009年 | 9篇 |
2008年 | 18篇 |
2007年 | 17篇 |
2006年 | 12篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 31 毫秒
21.
Carolina Merheb-Dini Graziele Aparecida Chiuchi Garcia Ana Lúcia Barretto Penna Eleni Gomes Roberto da Silva 《Food chemistry》2012
Prato cheeses were manufactured using coagulant from Thermomucor indicae-seudaticae N31 or a commercial coagulant. Cheeses were characterised using the following analysis: yield; fat; acidity; moisture; ash; salt; pH; total nitrogen; total protein; NS-pH 4.6/NT*100; NS-TCA 12%/NT*100; casein electrophoresis; and RP-HPLC. The results were statistically analysed and revealed that the proteolytic indices were not significantly different throughout the 60 days of ripening of cheeses made with either coagulant. Even though there were some quantitative differences in the peptide profile of cheeses, the enzyme from T. indicae-seudaticae N31 was used in the production of good quality Prato cheese without having to change the established technological parameters of the process. 相似文献
22.
Rebecca Kokkinofta Charalambos Fotakis Maria Zervou Panagiotis Zoumpoulakis Chara Savvidou Konstantina Poulli Charalambos Louka Naso Economidou Eleni Tzioni Katerina Damianou Sofia Loupasaki Panagiotis Kefalas 《Food Analytical Methods》2017,10(12):3902-3913
This study monitors variations in isotopes and elements in relation to grape variety, environmental factors and provenance in order to address the wine authenticity issue. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) assessed the wines’ elemental content. Site-specific nuclear isotope fractionation-nuclear magnetic resonance and isotope ratio mass spectrometry methodologies determined in authentic and commercial wines the distribution of the naturally occurring stable isotopes of the deuterium/hydrogen (D/H) ratios and carbon (13C/12C) in ethanol of wine and oxygen ratio (18O/16O) in wine water. Chemometrics delineated the elements and isotopes responsible for wine classification. Specifically, unsupervised principal component analysis (PCA) framed the importance of grape variety and provenance, while supervised analysis pinpointed the vineyard effect and highlighted the contribution of the vintage year. Validation steps ensured that the extracted models do not predict randomly and their results are reliable. In fact, the acquired results can be incorporated to the EU Wine Isotopic Databank database providing both a guide and a tool for eventual candidatures for denomination of origin and support both Cypriot wine and winemakers. In this context, this research contributes to authenticity assurance of wines and adds value to final products, while it helps controlling hazards arising from environmental changes. 相似文献
23.
Eleni E. Varsaki Vassilis Fotopoulos Athanassios N. Skodras 《Signal, Image and Video Processing》2013,7(2):247-253
In this paper, a new pattern-based fragile, semi-blind, spatial domain data hiding scheme is proposed. The Local Binary Pattern texture classification approach is used, in order to transparently and securely embed secret data into an image. Pixel values are modified in such a way that the texture satisfies the message requirements. The method is thoroughly studied and compared to other techniques in spatial domain in terms of capacity and image quality. The scheme performs well in images with smooth areas and can be used for authentication, tamper proofing, and secret communications. 相似文献
24.
A New Methodology for Efficient Classification of Multispectral Satellite Images Using Neural Network Techniques 总被引:1,自引:0,他引:1
A methodology based on self-organizing feature maps and indexing techniques for time and memory efficient neural network training and classification of large volumes of remotely sensed data is presented. Results on land-cover classification of multispectral satellite images using two popular neural models show orders of magnitude of speedup with respect to both training and classification times. The generality of the proposed methodology is demonstrated with a dramatic improvement of the classification time of the k-nearest neighbors statistical classifier. 相似文献
25.
26.
Sueva Cantalupo Vito Alessandro Lasorsa Roberta Russo Immacolata Andolfo Giuseppe DAlterio Barbara Eleni Rosato Giulia Frisso Pasquale Abete Gian Marco Cassese Giuseppe Servillo Ivan Gentile Carmelo Piscopo Matteo Della Monica Giuseppe Fiorentino Giuseppe Russo Pellegrino Cerino Carlo Buonerba Biancamaria Pierri Massimo Zollo Achille Iolascon Mario Capasso 《International journal of molecular sciences》2021,22(10)
Genome-wide association studies (GWAS) found locus 3p21.31 associated with severe COVID-19. CCR5 resides at the same locus and, given its known biological role in other infection diseases, we investigated if common noncoding and rare coding variants, affecting CCR5, can predispose to severe COVID-19. We combined single nucleotide polymorphisms (SNPs) that met the suggestive significance level (P ≤ 1 × 10−5) at the 3p21.31 locus in public GWAS datasets (6406 COVID-19 hospitalized patients and 902,088 controls) with gene expression data from 208 lung tissues, Hi-C, and Chip-seq data. Through whole exome sequencing (WES), we explored rare coding variants in 147 severe COVID-19 patients. We identified three SNPs (rs9845542, rs12639314, and rs35951367) associated with severe COVID-19 whose risk alleles correlated with low CCR5 expression in lung tissues. The rs35951367 resided in a CTFC binding site that interacts with CCR5 gene in lung tissues and was confirmed to be associated with severe COVID-19 in two independent datasets. We also identified a rare coding variant (rs34418657) associated with the risk of developing severe COVID-19. Our results suggest a biological role of CCR5 in the progression of COVID-19 as common and rare genetic variants can increase the risk of developing severe COVID-19 by affecting the functions of CCR5. 相似文献
27.
28.
Two carbon samples derived from poly(4-styrenesulfonic acid-co-maleic acid) based polymer by carbonization between 700 and 800 °C were oxidized to two different levels of surface acidity. The surfaces of resulting adsorbents were characterized by potentiometric titration, adsorption of nitrogen, FTIR, SEM/EDAX and thermal analysis. The materials were used as adsorbents of 4,6-dimethyldibenzothiophene (4,6-DMDBT) from hexadecane with initial concentration of sulfur between 10-150 ppmw. Although it was found that pores with diameter less than 10 Å govern the amount of 4,6-DMDBT adsorbed, that amount is enhanced when acidic groups are present in the larger pores owing to the contributions of specific interactions. Surface chemistry plays an important role in reactive adsorption and deposition of the products of surface reactions in the pore system. 相似文献
29.