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151.
Nuno Rodrigues Susana Casal Rebeca Cruz António M. Peres Paula Baptista José A. Pereira 《Journal of the American Oil Chemists' Society》2020,97(5):497-507
Tocopherols are compounds with high biological activity, beneficial for human health that can be found in vegetable oils like olive oil, contributing for its resistance to oxidation. In this work, the tocopherol contents of olive oils extracted from centenarian olive trees of six cultivars (cvs. Lentisca, Madural, Rebolã, Redondal, Verdeal, and Verdeal Transmontana) were evaluated during five consecutive crop seasons (2013–2017). Three tocopherol isoforms (α-, β- and γ-tocopherols) were detected in all analyzed olive oils, and their content varied significantly with the cultivar and year of production. The highest amounts were found in cv. Lentisca (456 ± 122 mg/kg olive oil), while the lowest were observed in cv. Verdeal (179 ± 45 mg/kg olive oil). Crop year was the most influential factor, with the highest contents observed in 2013 and lowest in 2014. Principal component analysis and hierarchical clustering analysis helped differentiate olive oils according to cultivar or production year. These data suggest that tocopherol composition may serve as a chemical marker to distinguish the subject cultivar olive oils from centenarian trees either by olive cultivar or by crop year, being some cultivars identified as potential candidates for guaranteeing the production of olive oils rich in these compounds. 相似文献
152.
Gabriel Morales Jose Iglesias Juan A. Melero Jovita Moreno Rebeca Sánchez-Vázquez Ángel Peral Alberto Cubo 《Topics in Catalysis》2017,60(15-16):1027-1039
The catalytic performance of two types of heterogeneous acid catalysts—sulfonic acid-functionalized materials and aluminum containing zeolites,—in the dehydration of sorbitol to isosorbide, in solventless and autogenous pressure conditions, has been studied. Catalysts screening evidenced strong differences between sulfonic acid-based materials and acid zeolites in terms of catalytic performance. Whereas sulfonic materials, such as Amberlyst-70 and SBA-15-Pr-SO3H, showed a very high catalytic activity, zeolites with beta structure evidenced good catalytic performance together with minimized promotion of side reactions (production of non-desired sorbitans, humins, etc.). Kinetic studies performed at different temperatures, adjusting to a Langmuir–Hinshelwood type model, allowed correlating the physicochemical properties of the acid materials with their catalytic performance in sorbitol dehydration. Thus, the analysis of initial selectivity through kinetic constants comparison indicated that commercial beta zeolite with a Si/Al ratio of 19 is the most selective catalyst for the production of isosorbide, though following a slower kinetics than the sulfonic materials. Furthermore, an equivalent hierarchical beta zeolite has been synthesised and evaluated, resulting in a slight improvement of the catalytic performance, in terms of both yield and selectivity to isosorbide. This improvement is attributed to the superior textural properties. 相似文献
153.
Alberto Canfrán-Duque Luis C. Barrio Milagros Lerma Gema de la Pe?a Jorge Serna Oscar Pastor Miguel A. Lasunción Rebeca Busto 《International journal of molecular sciences》2016,17(3)
First- and second-generation antipsychotics (FGAs and SGAs, respectively), have the ability to inhibit cholesterol biosynthesis and also to interrupt the intracellular cholesterol trafficking, interfering with low-density lipoprotein (LDL)-derived cholesterol egress from late endosomes/lysosomes. In the present work, we examined the effects of FGA haloperidol on the functionality of late endosomes/lysosomes in vitro. In HepG2 hepatocarcinoma cells incubated in the presence of 1,1′-dioctadecyl-3,3,3,3′-tetramethylindocarbocyanineperchlorate (DiI)-LDL, treatment with haloperidol caused the enlargement of organelles positive for late endosome markers lysosome-associated membrane protein 2 (LAMP-2) and LBPA (lysobisphosphatidic acid), which also showed increased content of both free-cholesterol and DiI derived from LDL. This indicates the accumulation of LDL-lipids in the late endosomal/lysosomal compartment caused by haloperidol. In contrast, LDL traffic through early endosomes and the Golgi apparatus appeared to be unaffected by the antipsychotic as the distribution of both early endosome antigen 1 (EEA1) and coatomer subunit β (β-COP) were not perturbed. Notably, treatment with haloperidol significantly increased the lysosomal pH and decreased the activities of lysosomal protease and β-d-galactosidase in a dose-dependent manner. We conclude that the alkalinization of the lysosomes’ internal milieu induced by haloperidol affects lysosomal functionality. 相似文献
154.
The viability of vinyltrimethoxy silane was investigated as a coupling agent for the manufacture of wood–plastic composites (WPC). The effect of silane pretreatment of the wood flour on the thermal and the dynamic mechanical properties and thermal degradation properties of the composites were studied. Moreover, the effect of organosilane on the properties of composites was compared with the effect of maleated polypropylene (MAPP). DSC studies indicated that the wood flour acts as a PP-nucleating agent, increasing the PP crystallization rate. In general, pretreatment with small amounts of silane improved this behavior in all the WPCs studied. Thermal degradation studies of the WPCs indicated that the presence of wood flour delayed degradation of the PP. Silane pretreatment of the wood flour augmented this effect, though without significantly affecting cellulose degradation. Studies of dynamic mechanical properties revealed that the wood flour (at up to 30 wt %) increased storage modulus values with respect to those of pure PP; in WPCs with a higher wood flour amount, there was no additional increase in storage modulus. Pretreatment of the wood flour with silane basically had no effect on the dynamic mechanical properties of the WPC. These results show that with small amounts of vinyltrimethoxy silane similar properties to the MAPP are reached. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
155.
María Sánchez-Campillo Elvira Larqué Daniel González-Silvera Rebeca Martínez-Tomás Manuel García-Fernández Francisco Avilés Anna Wellner Lucy Bialek Soledad Parra Marie Alminger Salvador Zamora Francisca Pérez-Llamas 《Food chemistry》2012
Ten subjects consumed one serving of an optimised or a reference soup produced using modified or traditional processing methods, respectively. Both soups contained the same proportions of carrot, tomato and broccoli, but with 5% olive oil in the optimised soup and 2.5% in the reference soup. The β-carotene content in 600 mL of the optimised/reference soups was 4.10/2.90 mg, and the lycopene content was 3.90/2.71 mg. The β-carotene and lycopene concentrations in chylomicrons isolated from blood serum samples were similar for both groups. Only 50% of subjects could be considered as carotenoid responders and, in agreement with in vitro accessibility data, the β-carotene concentration in the chylomicrons of these subjects was significantly higher in the group consuming the optimised soup, while no changes were found for lycopene. Postprandial chylomicrons from the optimised soup group exhibited significantly higher antioxidant activity in HepG2 cells than the other group. The stimulation of HepG2 cells by human postprandial chylomicrons seems useful for evaluating the antioxidant effect of different food matrices. 相似文献
156.
Pedro Daniel Alaniz-Lumbreras Roberto Augusto Gómez-Loenzo René de Jesús Romero-Troncoso Rebeca del Rocío Peniche-Vera Juan Carlos Jáuregui-Correa 《Machining Science and Technology》2013,17(2):263-274
One of the most important research topics in the area of Intelligent Manufacture Systems (IMS) is the automatic detection of tool breakage, wear of chipping during the cutting process. Sensor-based techniques are available for cutting force measurements, but there are drawbacks in this approach in cost and idle times. This work proposes a sensorless monitoring system for tool monitoring in order to detect breakage and chipping by exploiting the wavelet transform and a neural network. Previous works have made use of these tools for monitoring several machining parameters, but we propose an integrated low-cost approach to detect quickly the changes in the tool integrity for monitoring. The system output produces an accurate detection of the tool integrity that enables the system to prevent damage due to tool breakage. This approach allows for an industrial solution to be developed. 相似文献
157.
Trans fatty acids (TFA) are strongly correlated with an increased risk of cardiovascular and other chronic diseases. Current dietary recommendations exclude bakery products from frequent consumption basically due to their traditionally high content of TFA. 相似文献
158.
A social gamification framework for a K-6 learning platform 总被引:1,自引:0,他引:1
As video games, particularly, social games are growing in popularity and number of users, there has been an increasing interest in its potential as innovative teaching tools. Gamification is a new concept intending to use elements from video games in non-game applications. Education is an area with high potential for application of this concept since it seeks to promote people’s motivation and engagement. The research in progress will try to find how to apply social gamification in education, testing and validating the results of that application. To fulfil these objectives, this paper presents the guidelines and main features of a social gamification framework to be applied in an existent K-6 social learning environment. 相似文献
159.
A Six-valued Logic to Reason about Uncertainty and Inconsistency in Requirements Specifications 总被引:2,自引:0,他引:2
160.
Pereira BF Da Silva Alves RM Pitol DL Senhorini JA De Cássia Gimenes De Alcântara Rocha R Caetano FH 《Microscopy research and technique》2012,75(5):571-575
In this study, we investigated the effects of contaminated water on the blood parameters of the fish Prochilodus lineatus exposed during 7 and 20 days. Blood was collected with heparinized syringes, and blood smears were prepared and stained with Leishman stain. Slides were examined and photographed using a Leica light microscope. Total white blood cell counts and differential counts of thrombocytes and leukocytes were obtained for statistical analysis. The group exposed to water samples from Lago Azul exhibited an increase in the number of leukocytes and in the total number of white blood cells, suggesting that the chemical contaminants in this environment were acting similarly to antigens in this fish species, causing the proliferation of defense cells. In the group exposed to detergent during 20 days, the number of thrombocytes decreased. These results suggest that the variations in the number of leukocytes were indicators of environmental pollution and that biodegradable detergents may, after a certain time of exposure, affect vital functions in fish, such as coagulation and prevention of infections, which directly involves thrombocytes. 相似文献