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排序方式: 共有387条查询结果,搜索用时 109 毫秒
1.
Fuente Silvia A. Zubieta Carolina Ferullo Ricardo M. Belelli Patricia G. 《Topics in Catalysis》2019,62(12-16):908-917
Topics in Catalysis - Using the density functional theory, the mechanism of the water–gas shift reaction has been investigated employing a model catalyst formed by a Au5 cluster supported on... 相似文献
2.
Rufo L Rodríguez N Amils R de la Fuente V Jiménez-Ballesta R 《The Science of the total environment》2007,378(1-2):223-227
The Tinto River (Iberian Pyritic Belt) is a unique ecosystem characterized by extreme acidity and abnormally high concentrations of heavy metals in water, sediments and alluvium, with high microbial diversity and low plant diversity. The low pH value, a direct consequence of the high amount of Fe and S derived from the bedrock, promotes the dispersion of heavy metals. Less mobile elements (Fe, As, Pb, Ag and Ti) show the highest concentrations in the mid stretches of the river while easily mobile metals (Cu, Zn and Cd) accumulate in the estuarine sediments. Tinto River soils show a scarcity of nutrients (Ca, K, P, Mg and Na) due to the lack of lithologic sources and to loss by acid washing. Sea water and phospho-gypsum deposits near Huelva contribute to increase the Na, Mg and P concentrations in the estuarine soils. As a whole these features represent an extreme habitat to which plants must adapt. 相似文献
3.
Francisco Rey-García María T. Flores-Arias Luis C. Estepa Wilfried Assenmacher Werner Mader German F. de la Fuente 《International Journal of Applied Glass Science》2017,8(3):329-336
This study presents a Laser Zone Melting method with potential for producing planar waveguides at large scale, based on the surface coupling of two chemically compatible glass layers which exhibit distinct indices of refraction. The method is based on a recent patent, particularly applicable to process glass and ceramics with low thermal shock resistance. Glass coatings containing 76.24% by weight PbO are thus here reported, as obtained by this method on commercial soda-lime planar glass substrates. Their higher indices of refraction (1.58 vs 1.52 for commercial soda-lime glass) result in attractive waveguiding potential, as demonstrated with measurements using focused light from a He-Ne laser beam. Scanning and transmission electron microscopy studies reveal excellent integration and compatibility between the observed coatings and substrates, where diffusion in the proximity of the interface was studied by EDS analysis. Crystalline phases have not been found within the coating, or within the substrate, as concluded from the absence of Bragg-peaks in XRD experiments. 相似文献
4.
5.
Abhishek Gawasane Laura Bix Javier de la Fuente Raghav Prashant Sundar Timothy J. Smith 《Packaging Technology and Science》2012,25(7):385-396
The study consisted of three objectives: (a) to test the relative prominence and conspicuousness of a warning required by US law to be conspicuous; (b) to explore whether or not the conspicuousness of the said warning can be enhanced graphically; and (c) to develop preliminary data for power analysis that would guide decisions related to sample size in future studies. Seventeen subjects viewed four over‐the‐counter drug packages (each with a different style of warning) along with five other products while wearing an eye tracking device. Four styles of warning were used on the over‐the‐counter drug packages: no outline and no fill, outline and no fill, no outline and fill, and outline and fill. The surface area and the placement of the warnings were held constant across all four designs and were consistent with those on commercially available products. Collected data were broken into five zones: warning, brand name, strength, product benefit and net weight. Despite the fact that US law requires it to be conspicuous, the tested warning was significantly less noticeable than the brand name (objective one) for all dependent variables analyzed (α = 0.05). No significant difference was indicated for the varied warning designs (objective two). This could be because not much can be done to enhance prominence when constrained to the limited space that is typically used for such warnings or because of the limited sample size. Power calculations suggest that a sample size of nearly 200 subjects would be required to detect a 2.5 s mean difference at 80% confidence (objective three). Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
6.
Long-term atmospheric corrosion of mild steel 总被引:3,自引:0,他引:3
A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4–6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals). 相似文献
7.
Intratumoral Thermal Reading During Photo‐Thermal Therapy by Multifunctional Fluorescent Nanoparticles 下载免费PDF全文
Elisa Carrasco Blanca del Rosal Francisco Sanz‐Rodríguez Ángeles Juarranz de la Fuente Patricia Haro Gonzalez Ueslen Rocha Kagola Upendra Kumar Carlos Jacinto José García Solé Daniel Jaque 《Advanced functional materials》2015,25(4):615-626
The tremendous development of nanotechnology is bringing us closer to the dream of clinical application of nanoparticles in photothermal therapies of tumors. This requires the use of specific nanoparticles that must be highly biocompatible, efficient light‐to‐heat converters and fluorescent markers. Temperature reading by the heating nanoparticles during therapy appears of paramount importance to keep at a minimum the collateral damage that could arise from undesirable excessive heating. In this work, this thermally controlled therapy is possible by using Nd3+ ion‐doped LaF3 nanocrystals. Because of the particular optical features of Nd3+ ions at high doping concentrations, these nanoparticles are capable of in vivo photothermal heating, fluorescent tumor localization and intratumoral thermal sensing. The successful photothermal therapy experiments here presented highlight the importance of controlling therapy parameters based on intratumoral temperature measurements instead of on the traditionally used skin temperature measurements. In fact, significant differences between intratumoral and skin temperatures do exist and could lead to the appearance of excessive collateral damage. These results open a new avenue for the real application of nanoparticle‐based photothermal therapy at clinical level. 相似文献
8.
Structural Determinants of the Selectivity of 3‐Benzyluracil‐1‐acetic Acids toward Human Enzymes Aldose Reductase and AKR1B10 下载免费PDF全文
Dr. Francesc X. Ruiz Alexandra Cousido‐Siah Dr. Sergio Porté Dr. Marta Domínguez Isidro Crespo Chris Rechlin Dr. André Mitschler Prof. Dr. Ángel R. de Lera Dr. María Jesús Martín Dr. Jesús Ángel de la Fuente Prof. Dr. Gerhard Klebe Prof. Dr. Xavier Parés Prof. Dr. Jaume Farrés Dr. Alberto Podjarny 《ChemMedChem》2015,10(12):1989-2003
The human enzymes aldose reductase (AR) and AKR1B10 have been thoroughly explored in terms of their roles in diabetes, inflammatory disorders, and cancer. In this study we identified two new lead compounds, 2‐(3‐(4‐chloro‐3‐nitrobenzyl)‐2,4‐dioxo‐3,4‐dihydropyrimidin‐1(2H)‐yl)acetic acid (JF0048, 3 ) and 2‐(2,4‐dioxo‐3‐(2,3,4,5‐tetrabromo‐6‐methoxybenzyl)‐3,4‐dihydropyrimidin‐1(2H)‐yl)acetic acid (JF0049, 4 ), which selectively target these enzymes. Although 3 and 4 share the 3‐benzyluracil‐1‐acetic acid scaffold, they have different substituents in their aryl moieties. Inhibition studies along with thermodynamic and structural characterizations of both enzymes revealed that the chloronitrobenzyl moiety of compound 3 can open the AR specificity pocket but not that of the AKR1B10 cognate. In contrast, the larger atoms at the ortho and/or meta positions of compound 4 prevent the AR specificity pocket from opening due to steric hindrance and provide a tighter fit to the AKR1B10 inhibitor binding pocket, probably enhanced by the displacement of a disordered water molecule trapped in a hydrophobic subpocket, creating an enthalpic signature. Furthermore, this selectivity also occurs in the cell, which enables the development of a more efficient drug design strategy: compound 3 prevents sorbitol accumulation in human retinal ARPE‐19 cells, whereas 4 stops proliferation in human lung cancer NCI‐H460 cells. 相似文献
9.
ABSTRACT To study the importance of hydrophobic interaction on the mechanism of acid milk gel formation, milk coagulation process was monitored at 30 °C in presence of various levels of sodium dodecyl sulphate (SDS). As a function of the SDS concentration, acid milk coagulability was either enhanced or reduced. Main pH‐induced biochemical changes were preserved despite the presence of SDS (such as pH‐induced demineralization and pH‐induced protein solubilization). It could be assumed that SDS‐modified casein micelles ability to coagulate by lowering of pH might seem to be governed essentially by the level of SDS‐induced k‐casein micellar dissociation, at natural milk pH. 相似文献
10.
The observation that carbon activation by KOH gives rise to a significant formation of cyanide moieties is confirmed. However, contrary to what has been reported, our results show that the N2 used as an atmosphere during the activation process has little to do with the formation of such cyanide moieties. The main source of cyanides is ascribed to structural nitrogen already present in the precursors. Reducing species (H2 and metallic K) formed during the KOH carbon activation process might promote the transformation of that structural nitrogen to cyanides. In order to minimise cyanide formation (and related environmental concerns), materials with low nitrogen content should be selected as precursors for the preparation of KOH-activated carbons. 相似文献