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51.
L. Calcagnile M. D’Elia G. Quarta M. Vidale 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(7-8):1030-1033
The low amount of material needed for the measurements makes AMS radiocarbon a technique suitable for the dating of ancient bronze artefacts through the analysis of the organic residues contained into the casting cores. We present the results of the AMS radiocarbon dating analyses carried out on the organic remains extracted from the casting cores of the Riace bronzes, among the most famous and well preserved sculptures of the Greek-Classical period. Although different dating hypotheses have been suggested on the base of stylistic considerations, no conclusive answers are, so far, available. The sample selection and preparation protocols of the different kind of organic materials (charred wood, vegetal remains and animal hairs) are described as well as the interpretation of the results in the frame of the current dating hypotheses and available analytical information about the casting technology. 相似文献
52.
Lucio Di Matteo 《Bulletin of Engineering Geology and the Environment》2012,71(1):79-85
For liquid limit determination, the European Standards require the cone penetrometer technique or, alternatively, the Casagrande
cup method; but the latter is widely used in practice. As most European soil classification systems are not adapted to the
new European Standards, a systematic study was carried out to verify the differences between the two techniques for liquid
limit determination, examining clayey soils from various geologic units. Comparison of 100 liquid limit values ranging between
20 and 50% indicates that the liquid limit obtained by the fall cone method is generally 2.2% points higher than that obtained
by the hard base Casagrande apparatus. Comparison of data from different sources consistently indicates that the equation
proposed in this study may be useful in revising existing soil classification systems, avoiding problems of soil classification
due to the technique used for liquid limit determination. 相似文献
53.
Andrea Martinelli Massimo Calì Lucio D'Ilario Iolanda Francolini Antonella Piozzi 《应用聚合物科学杂志》2012,123(5):2697-2705
In the first part of this article, we reported the crystalline memory effect on the nonisothermal crystallization of poly(L ‐lactide). The experiments were carried out by using polymer single crystals growth from dilute solution as standard starting material. In this article (Part II), we have analyzed in detail the effect of the melting condition on the overall crystallization kinetics by applying the Nakamura‐Avrami model to DSC results. The absence or the low concentration of foreign infusible heterogeneous nuclei in our system allowed us to exalt the self‐nuclei role in polymer crystallization, to follow their concentration decrease during the melting process and to find the limiting melting temperature for their disappearance. Below such a temperature, a stable equilibrium number of self‐nuclei was observed, probably deriving from ordered structures, persisting in the melt, and originated from the single crystals thickening process during the polymer dynamic melting in the DSC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
54.
E. Andrade A. Romero NúñezA. Ibarra Palos J. CruzM.F. Rocha C. SolisO.G. de Lucio E.P. Zavala 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(4):440-443
Lithium manganese oxide, LiMn2O4, has been studied by many research groups. This material is a great candidate to be used as positive electrode in rechargeable lithium-ion batteries because of its low cost, abundant precursors and non-toxicity. LiMn2O4 has a spinel Fd-3m structure and shows a reversible extraction and insertion of lithium ions that is one of the most important characteristic of positive electrodes in rechargeable batteries.In this work, LiMn2O4 samples were synthesized by solid state reaction. A partial lithium removal was performed on this system by chemical delithiation using HCl aqueous solutions at different concentrations. Six partial-extracted compounds were obtained and characterized by Ion beam analysis (IBA) in order to obtain the Li concentrations. X-ray diffraction (XRD) and Rietveld analyses were also performed. A rigorous study of lithium contents is critical to analyze the structure properties of these compounds and samples production parameters. The IBA method used in this work was the analysis of energy spectra of elastic backscattered (EBS) proton from Mn, O and Li nuclei and the α-particles energy from the 7Li(p,α)4He nuclear reaction (NR). 相似文献
55.
The deterioration attributable to corrosion of concrete structures reinforced with unbonded, posttensioned tendons is a costly problem. Recent research has shown composite materials such as fiber-reinforced polymers (FRP) to be suitable alternatives to steel because they provide similar strength without susceptibility to electrochemical corrosion. Carbon-FRP (CFRP) in particular has great promise for prestressed applications because it shows resistance to corrosion in environments that might be encountered in concrete and experiences less relaxation than steel. This paper outlines the testing and implementation of a posttensioned system that uses CFRP tendons to replace corroded, unbonded posttensioned steel tendons. This system was then implemented in a parking garage in downtown Toronto. To the writers’ knowledge, this is the first example of an unbonded, posttensioned tendon replacement using FRP tendons. The system used split-wedge anchors designed specifically for CFRP tendons. The dead end was anchored by directly bonding the tendon to the concrete slab. The CFRP tendon was successfully inserted in the opening created by the removal of the corroded tendon and stressed. Although the system was shown to be feasible, the current anchorage configuration results in load losses of up to 60% during the transfer. Changing the orientation of the anchor was found to reduce the load loss to an acceptable range of 1–9%. 相似文献
56.
Ivor M. do Prado Willyan M. Giufrida Víctor H. Alvarez Vladimir F. Cabral Sócrates Quispe-Condori Marleny D. A. Saldaña Lucio Cardozo-Filho 《Journal of the American Oil Chemists' Society》2011,88(8):1263-1269
New data on phase equilibria for Sacha inchi seed oil in carbon dioxide have been measured using a variable volume cell phase
equilibria system at temperatures of 303, 313 and 323 K and at pressures ranging from 4.3 to 27.7 MPa. The CO2 mole fraction varied from 0.7488 to 0.9997. At the studied concentrations, phase transitions of vapor-liquid, liquid-liquid-vapor
and liquid-liquid were observed. Sacha inchi oil contains 47% of omega-3 fatty acids, with a ratio of 0.76:1 for omega-6:omega-3,
which is good for human health. The Peng-Robinson equation of state was used to describe the experimental data. A qualitative
agreement was obtained between experimental and calculated data for the binary system CO2 and Sacha inchi seed oil. 相似文献
57.
58.
Lucio Boschetti Matteo Ottavian Pierantonio Facco Massimiliano Barolo Lorenzo Serva Stefania Balzan Enrico Novelli 《Meat science》2013
The use of near-infrared spectroscopy (NIRS) is proposed in this study for the characterization of the quality parameters of a smoked and dry-cured meat product known as Bauernspeck (originally from Northern Italy), as well as of some technological traits of the pork carcass used for its manufacturing. In particular, NIRS is shown to successfully estimate several key quality parameters (including water activity, moisture, dry matter, ash and protein content), suggesting its suitability for real time application in replacement of expensive and time consuming chemical analysis. Furthermore, a correlative approach based on canonical correlation analysis was used to investigate the spectral regions that are mostly correlated to the characteristics of interest. The identification of these regions, which can be linked to the absorbance of the main functional chemical groups, is intended to provide a better understanding of the chemical structure of the substrate under investigation. 相似文献
59.
Comparison of nine common coffee extraction methods: instrumental and sensory analysis 总被引:3,自引:0,他引:3
Alexia N. Gloess Barbara Schönbächler Babette Klopprogge Lucio D`Ambrosio Karin Chatelain Annette Bongartz André Strittmatter Markus Rast Chahan Yeretzian 《European Food Research and Technology》2013,236(4):607-627
The preparation of a cup of coffee may vary between countries, cultures and individuals. Here, an analysis of nine different extraction methods is presented regarding analytical and sensory aspects for four espressi and five lunghi. This comprised espresso and lungo from a semi-automatic coffee machine, espresso and lungo from a fully automatic coffee machine, espresso from a single-serve capsule system, mocha made with a percolator, lungo prepared with French Press extraction, filter coffee and lungo extracted with a Bayreuth coffee machine. Analytical measurements included headspace analysis with HS SPME GC/MS, acidity (pH), titratable acidity, content of fatty acids, total solids, refractive indices (expressed in °Brix), caffeine and chlorogenic acids content with HPLC. Sensory analysis included visual, aroma, flavor and textural attributes as well as aftersensation. The technical differences in the extraction methods led to a higher concentration of the respective quantities in the espressi than in the lunghi. Regarding the contents per cup of coffee, the lunghi generally had a higher content than the espressi. The extraction efficiency of the respective compounds was mainly driven by their solubility in water. A higher amount of water, as in the extraction of a lungo, generally led to higher extraction efficiency. Comparing analytical data with sensory profiles, the following positive correlations were found total solids ? texture/body, headspace intensity ? aroma intensity, concentrations of caffeine/chlorogenic acids ? bitterness and astringency. 相似文献
60.
Demétrius Paiva Arçari Juliana Carvalho Santos Alessandra Gambero Lucio Fábio Caldas Ferraz Marcelo Lima Ribeiro 《Molecular nutrition & food research》2013,57(10):1882-1885
The aim of this study was to evaluate the effects of yerba maté (YM) extract on the phosphatidylinositol 3‐kinase (PI3K)‐AKT signaling pathway in vivo. The mice were introduced to either standard‐ or high‐fat diet (HFD). After 8 weeks on an HFD, mice were randomly assigned to one of the two treatment conditions, water or yerba maté extract at 1.0 g/kg. After treatment, glucose blood level and hepatic insulin response were evaluated. Liver tissue was examined to determine the mRNA levels using the PI3K‐AKT PCR array. The nuclear translocation of forkhead box O1 (FOXO1) was determined by an electrophoretic mobility‐shift assay. Our data demonstrated that yerba maté extract significantly decreased the final body weight, glucose blood levels, and insulin resistance of mice. Molecular analysis demonstrated that an HFD downregulated Akt2, Irs1, Irs2, Pi3kca, Pi3kcg, and Pdk1; after yerba maté treatment, the levels of those genes returned to baseline. In addition, an HFD upregulated Pepck and G6pc and increased FOXO1 nuclear translocation. The intervention downregulated these genes by decreasing FOXO1 nuclear translocation. The results obtained demonstrate for the first time the specific action of yerba maté on the PI3K‐AKT pathway, which contributed to the observed improvement in hepatic insulin signaling. 相似文献