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681.
Rocha MA Winnischofer H Araki K Anaissi FJ Toma HE 《Journal of nanoscience and nanotechnology》2011,11(5):3985-3996
Nickel hydroxide can provide an outstanding cathode material in alkaline secondary batteries, however the progressive decrease of the charge capacity as a function of the number of oxidation/reduction cycles is a challenging problem to be solved. New improvements on the electrochemical properties of electrode materials can be achieved by exploiting the much better performance of alpha-nickel hydroxide. Such materials were obtained in a stable form by sol-gel method and characterized by thermogravimetric analyses, UV-Vis spectroscopy, X-ray diffractometry, scanning and transmission electron microscopy, cyclic voltammetry and electrochemical quartz crystal microbalance techniques. The results revealed not only the formation of the alpha-Ni(OH)2 phase, but also a much better electrochemical reversibility and stability as compared with similar materials obtained by electrochemical precipitation method. 相似文献
682.
Sílvia Tondella Dantas Beatriz Maria Curtio Soares Elisabete Segantini Saron Fiorella Balardin Hellmeister Dantas Jozeti Aparecida Barbutti Gatti Paulo Henrique Massaharu Kiyataka 《Packaging Technology and Science》2014,27(6):449-456
The consumption of canned food products from dented cans is not recommended by surveillance and consumer protection agencies due to the possibility of aluminium pick up, which may migrate from package to food/beverage. However, it is necessary to raise scientific data that will support any decision concerning the consumption of this kind of food, especially when the percentage of undernourished persons all over the world is considerable. Drawn and wall ironing–type aluminium cans with 330 ml of ready‐to‐drink grape juice, under three different controlled conditions of can damage as well as without damage, were evaluated for 1 year at 35°C. Aluminium migration, internal pressure and can internal surface appearance were periodically evaluated in order to monitor the package/beverage interaction. The results showed very small variation on the can internal surface appearance and pressure. Even after storage for 365 days, no can presented perforation, although the aluminium migration was increased. The highlight of this work is that after 1 year, for all the evaluated damage conditions, the ready‐to‐drink grape juice in aluminium cans could be considered adequate for human consumption in terms of metal migration from packaging. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
683.
Incorporation of high oil content in polyvinyl acetate nanoparticles produced by batch miniemulsion polymerization stabilized with a polymeric stabilizer
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Nanoparticles (NPs) have been widely applied in the biomedical area. In order to satisfy the requirements for biomedical applications, sodium lauril sulfate (SLS) and hexadecane, widely used as anionic surfactant and co‐stabilizer, were successfully replaced by biocompatible compounds, in order to obtain poly(vinyl acetate) (PVAc) NPs via miniemulsion polymerization. The incorporation of high oil content in PVAc NPs was investigated, using different poly(vinyl alcohol) (PVOH) concentrations as polymeric surfactant. Besides the polymeric surfactant, lecithin and Miglyol 812, a triacylglycerol of saturated fatty acids obtained from coconut oil, were used as surfactant and co‐stabilizer, respectively. A high Miglyol 812 content was incorporated in the PVAc NPs and the morphology was investigated by TEM. The influence of PVOH concentration on the droplet nucleation mechanism and final morphology of PVAc NPs was evaluated. High PVOH concentration favored micellar particle nucleation. According to the TEM images, hemispheres nanoparticles were obtained. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41365. 相似文献
684.
The oriented strandboard (OSB) has less dimensional stability than plywood, but they are competitive panels and have been used for similar ends. The wood-water relation variables, such as thickness swelling and water absorption, express this OSB dimensional instability and can be explained by two main factors: wood hygroscopicity and imposed hot-pressing stresses. The objective of this present paper was to propose a thermal post-treatment as a method to improve OSB dimensional stability by decreasing wood hygroscopicity and releasing hot-pressing stress. OSB panels from Pinus taedawood were produced in laboratory, and their characteristics were: single layer, 0.8 g/cm3; 8% phenolic resin and without wax. The OSB panels were treated in a laboratory press at 250 °C for about 4, 7 and 10 minutes. The wood-water relation variables, thickness swelling (TS), water absorption (WA), equilibrium moisture content (EMC) and springback or permanent thickness swelling (PTS) were determined and compared with untreated panels. The results showed that the proposed thermal treatment was effective to reduce TS, EMC and PTS, but didn’t affect WA which was affected by panel density reduction. The longer the treatment the higher the dimensional stability, and panel weight loss could be used as predictive variable for the efficiency of the treatment. 相似文献
685.
Henrique Silvano Arruda Gustavo Araujo Pereira Glaucia Maria Pastore 《Food Analytical Methods》2017,10(1):100-110
In this study, response surface methodology was used to optimize the extraction temperature (25–75 °C) and ethanol concentration (0–70 %, ethanol/water, v/v) to maximize the extraction of total phenolic compounds (TPC) from araticum pulp. The efficiency of the extraction process was monitored over time, and equilibrium conditions were reached between 60–90 min. A second-order polynomial model was adequately fit to the experimental data with an adjusted R 2 of 0.9793 (p < 0.0001) showing that the model could efficiently predict the TPC content. Optimum extraction conditions were ethanol concentration of 46 % (v/v), extraction temperature of 75 °C and extraction time of 90 min. Under the optimum conditions, the araticum pulp showed high TPC content (4.67 g GAE/100 g dw) and also high antioxidant activity in the different assays used (46.56 μg/mL, 683.65 μmol TE/g and 1593.72 μmol TE/g for DPPH IC50, TEAC and T-ORACFL, respectively). From our extraction procedure, we successfully recovered a significantly higher amount of TPC compared to other studies in the literature to date (1.5–22-fold higher). Furthermore, TPC and antioxidant activity were present in the fruit in levels that are difficult to find in other common fruits. These results expose a potential approach for improving human health through consumption of araticum fruit. 相似文献
686.
Marcelo Rodrigues da Silva Pelissari Luan Pereira Camargo Fenelon Martinho Lima Pontes Luiz Henrique Dall'Antonia 《Coloration Technology》2023,139(6):742-757
In this work, bismuth oxychloride with a rose-type flower shape was successfully synthesised using the easy and low-cost successive ionic layer adsorption and reaction process. The tetragonal crystalline structure with a flower-like shape and thickness of 150-nm nanosheets was used as electrode material in an exciting approach for the photoelectrochemical discoloration reaction of methyl orange. The structure, morphology and optical properties of the obtained bismuth oxychloride sample were evaluated through X-ray diffraction, Raman spectroscopy, the Brunauer–Emmett–Teller method, diffuse reflectance ultraviolet–visible spectroscopy and scanning electron microscopy. Through photoelectrochemical characterisation measurements (linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques), the bismuth oxychloride electrode showed remarkable electroactivity under ultraviolet light irradiation. The methyl orange discoloration reaction, performed under ultraviolet light incidence and potential application of −0.5 V (vs silver/silver chloride) for 60 minutes, produced a higher degradation percentage (ca. 82%) and kobs of 29 × 10−3 min−1. 相似文献
687.
688.
Amélia Guimarães Carvalho Antonio José Vinha Zanuncio Benedito Rocha Vital Angélica de Cássia Oliveira Carneiro Carlos Miguel Simões da Silva Gustavo Henrique Denzin Tonoli 《Holz als Roh- und Werkstoff》2018,76(1):155-162
The aim of this study was to evaluate the effect of hydrothermal treatment in strand particles of pine used for oriented strand boards (OSB) production. Strand particles of pine were hydrothermally treated at 130, 150 and 170 °C for 7 and 21 min, for the determination of chemical composition, pH, equilibrium moisture content, particles mass loss, and contact angle of these particles with phenol–formaldehyde resin. Afterwards, OSB panels were produced using 8% phenol–formaldehyde resin, with a nominal density of 0.7 g/cm3, and pressing cycle at 170 °C and 3.14 MPa for 8 min. Then, the panels were kept in climate chamber until mass stabilization for the determination of their physical and mechanical properties, and for comparison with the European standards. The hydrothermal treatment in the particles decreased carbohydrate, especially mannan, xylan and arabinans, resulting in reduced equilibrium moisture content, pH, and contact angle, and increasing buffer capacity and mass loss. In OSB panels, treated particles caused the drop in the equilibrium moisture content and reduction of the thickness swelling of the panel, without reducing the mechanical strength, making the hydrothermal treatment very attractive. The hydrothermal treatment at 170 °C for 7 min allowed the resulting OSB panel being classified into the categories 1 and 2 of the European standard, expanding its range of use. 相似文献
689.
690.
Caroline Ramos-Souza Daniel Henrique Bandoni Adriana Pavesi Arisseto Bragotto Veridiana Vera De Rosso 《Comprehensive Reviews in Food Science and Food Safety》2023,22(1):380-407
The food industry uses dyes mainly to overcome color loss during the processing and storage of products, with the azo dyes currently being the most employed. Studies on the safety of using these dyes in foods started in the 1950s and have indicated the potential for concern. This review discusses the risk assessment of food intake containing artificial azo dyes. There are case reports and, subsequently, double-blind placebo-controlled trials in some individuals who may experience adverse effects from the intake of azo dyes, but it is unclear whether these adverse effects are restricted to specific populations or more generalized. In view of this, different toxicological endpoints are evaluated to verify toxic effects in in vitro and in vivo models and to establish the no observed adverse effect level. Exposure estimation studies have shown that human exposure to azo dyes via oral intake is mainly below the acceptable daily intake established by advisory bodies. However, most countries do not have studies that estimate the oral intake of azo dyes. In this case, local food diversity and racial–ethnic specificities are not considered when stating the exposure estimate is below the acceptable daily intake for the human population and thus may not represent actual intake. Concerning the scenario established above, this review discusses the most critical gaps to be overcome to contribute to the direction of future studies and the development of more effective public policies concerning the safety of the intake of artificial azo dyes. 相似文献