全文获取类型
收费全文 | 584篇 |
免费 | 64篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 159篇 |
金属工艺 | 4篇 |
机械仪表 | 5篇 |
建筑科学 | 29篇 |
能源动力 | 24篇 |
轻工业 | 95篇 |
水利工程 | 7篇 |
无线电 | 45篇 |
一般工业技术 | 124篇 |
冶金工业 | 42篇 |
原子能技术 | 6篇 |
自动化技术 | 105篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 31篇 |
2020年 | 24篇 |
2019年 | 16篇 |
2018年 | 23篇 |
2017年 | 28篇 |
2016年 | 23篇 |
2015年 | 21篇 |
2014年 | 44篇 |
2013年 | 40篇 |
2012年 | 38篇 |
2011年 | 40篇 |
2010年 | 31篇 |
2009年 | 30篇 |
2008年 | 22篇 |
2007年 | 22篇 |
2006年 | 18篇 |
2005年 | 21篇 |
2004年 | 16篇 |
2003年 | 10篇 |
2002年 | 21篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有648条查询结果,搜索用时 203 毫秒
1.
Policicchio Alfonso Putz Ana-Maria Conte Giuseppe Stelitano Sara Bonaventura Carlo Poselle Ianăşi Cătălin Almásy László Wacha András Horváth Zsolt Endre Agostino Raffaele G. 《Journal of Porous Materials》2021,28(4):1049-1058
Journal of Porous Materials - The present study reports a systematic analysis of morphology and hydrogen sorption capacity of mesoporous organic-inorganic silica prepared by varying the silica... 相似文献
2.
Matteo Bordiga Raffaele Guzzon Roberto Larcher Fabiano Travaglia Marco Arlorio Jean Daniel Coïsson 《International Journal of Food Science & Technology》2020,55(2):559-568
Wine is a fermented beverage that could be affected by high concentrations of biogenic amines, thus altering organoleptic and health properties. In this work, the capacity of different selected yeast strains regarding to affect the content of tyramine, histamine, 2-phenylethylamine, tryptamine and their precursor amino acids (pAA) during fermentation has been described. Overall, biogenic amines (BAs) and pAA contents appeared significantly related both to the strain and to the nutrient supplementation applied. Among BAs, without and (with) nitrogen source addition, the concentrations covered a range between 0.1 and 9.5 (0.1–10.3) mg L−1 for tyramine; 0.1 and 4.4 (0.1–4.6) mg L−1 for histamine; 0.4 and 1.1 (0.4–1.4) mg L−1 for 2-phenylethylamine; and 0.02 and 0.14 (0.01–0.12) mg L−1 for tryptamine, respectively. Considering that also wine yeast species are responsible for BAs formation, the evidence from fermentation trials underlined the relevance of a careful choice of ADY strains and nitrogen sources in the management of alcoholic fermentation in wine. 相似文献
3.
4.
5.
Water Resources Management - The provision of critical services, such as drinking water, is crucial both in ordinary and in emergency conditions due to either natural (e.g. earthquakes, droughts,... 相似文献
6.
Raffaele Romano Alessandra Aiello Fabiana Pizzolongo Andrea Rispoli Lucia De Luca Paolo Masi 《International Journal of Food Science & Technology》2020,55(10):3334-3342
Tomato waste is characterised by high amounts of bioactive compounds, such as carotenoids, polyphenols and essential fatty acids. In this work, oleoresins were produced from tomato waste (skins + seeds) and skins using carbon dioxide under liquid and supercritical conditions. The use of ethanol as a co-solvent was also evaluated. Compositions of the oleoresins were analysed and compared to oleoresin obtained by means of an organic solvent, which was used as the control. Oleoresin extraction from the waste by liquid and supercritical CO2 provided the highest yields (12.5%–12.9%). The extracts obtained from the skins with supercritical CO2 without ethanol had the highest content of α- and γ-tocopherols (80 and 575 mg/100 g oleoresin, respectively), while lycopene and β-carotene were found at 205 and 75 mg/100 g oleoresin, respectively. The highest quantity of polyphenols (9305 mg GAE/100 g oleoresin) was found in the oleoresin extracted from skin by supercritical CO2 with ethanol. All oleoresins were characterised by a high antioxidant activity, which improved with the synergy of carotenoids, tocopherols and polyphenols. 相似文献
7.
Roberta D’Ambrosio Alessio Aghemo Raffaele De Francesco Maria Grazia Rumi Enrico Galmozzi Stella De Nicola Cristina Cheroni Paul J. Clark Guido Ronchi Pietro Lampertico Massimo Colombo 《International journal of molecular sciences》2014,15(5):7213-7224
The interleukin 28B (IL28B) rs12979860 polymorphism is associated with treatment outcome in hepatitis C virus (HCV) genotype 1 and 4 patients. Its association with the histological features of chronic hepatitis C and disease severity needs further clarifications. To assess the correlation between IL28B genotype, HCV genotype and liver biopsy findings in untreated patients.
Materials and Methods
Pre-treatment liver biopsies from 335 HCV Caucasian patients (59% males, age 50 years) enrolled in the MIST study were staged for fibrosis and inflammation according to the METAVIR and the Ishak scoring systems; steatosis was dichotomized as <5% or ≥5%. IL28B was typed by Taqman Single Nucleotide Polymorphism (SNP) genotyping assay. HCV genotype was 1 in 151 (45%), 2 in 99 (30%), 3 in 50 (15%) and 4 in 35 (10%) patients. IL28B genotype was CC in 117 (34%), CT in 166 (49%) and TT in 52 (15%). At univariate analysis, the IL28B CC genotype was associated with severe portal inflammation in HCV-1 patients (CC vs. CT/TT: 86% vs. 63%, p = 0.005), severe lobular inflammation in HCV-2 patients (CC vs. CT/TT: 44% vs. 23%, p = 0.03), and less fatty infiltration in HCV-1 patients (CC vs. CT/TT: 72% vs. 51%, p = 0.02). Despite the lack of any association between IL28B and fibrosis stage, in HCV-3 patients IL28B CC correlated with METAVIR F3–F4 (CC vs. CT/TT: 74% vs. 26%, p = 0.05). At multivariate analysis, the genotype CC remained associated with severe portal inflammation in HCV-1, only (Odds Ratio (OR): 95% Confidence Interval (CI): 3.24 (1.23–8.51)). IL28B genotype is associated with the histological features of chronic hepatitis C in a HCV genotype dependent manner, with CC genotype being independently associated with severe portal inflammation. 相似文献8.
Raffaele Vinai Fabrice Ntimugura Will Cutbill Robert Evans Yize Zhao 《International Journal of Applied Ceramic Technology》2022,19(3):1235-1248
Alkali activated binders are a promising alternative to the use of Portland cement in the manufacture of concrete for curbing CO2 emissions. Novel sources of silicates have been investigated in recent years for reducing cost and environmental impacts associated with the use of chemical activators. This study describes the production of solid sodium silicate (SS) activating powder from bamboo leaf ash (BLA). Bamboo leaves were calcined at 550–800°C, mixed with NaOH pellets, and heated in an oven at 300°C. The obtained silicate powder was used for activating blended fly ash/slag samples. Mechanical and microstructural properties of BLA-based samples were compared to those of samples made with commercially available chemicals. The strength of BLA-activated mortars matched the commercially-sourced activators, being 25–30 MPa at 7 days and exceeding 40 MPa at 28 days. The microstructural analysis suggested that BLA-based SS showed a lesser degree of dissolution of precursors at 7 days, but the quality of the matrix was higher than that of NaOH-activated samples. These results confirmed that the reactivity of BLA-silicate powder was similar to that of commercial SS solutions, and show the potential valorization of future biomass renewable waste in the production of low carbon, alkali-activated concretes. 相似文献
9.
Enrico Binetti Marinella Striccoli Teresa Sibillano Cinzia Giannini Rosaria Brescia Andrea Falqui Roberto Comparelli Michela Corricelli Raffaele Tommasi Angela Agostiano M Lucia Curri 《Science and Technology of Advanced Materials》2015,16(5)
Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700–850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices. 相似文献
10.
Metal–Organic Frameworks: Biomimetic Replication of Microscopic Metal–Organic Framework Patterns Using Printed Protein Patterns (Adv. Mater. 45/2015) 下载免费PDF全文