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991.
José M. Sendra José V. Carbonell Maria J. Gosalbes Victoria Todo 《Journal of the Institute of Brewing》1989,95(5):327-332
The FIA-fluorimetric methods for the determination of β-glucan in worts and beers have been investigated, modified and improved. Fluorescence is excited by using a mercury lamp and a 338 nm band-pass excitation filter, and detected using a 425 nm long-pass emission filter. It has been found that an increase of the ionic strength of the eluent, up to a maxium of 1% Sodium Chloride, increases the range of β-glucan molecular weights effectively bound by Calcofluor. The influence of the low molecular weight components of wort and beer: dextrins, aminoacids, etc, has been studied and found that their effect is negligible. The interference of wort and beer colour on the measurement of β-glucan has been quantified and several approaches are given to overcome it. Thirty-six European beers have been analyzed for β-glucan content. The possible detection of the addition of exogenous β-glucanases to wort and beer is discussed. 相似文献
992.
Stuchly Maria A. Kraszewski Andrzej Stuchly Stanislaw S. 《IEEE transactions on bio-medical engineering》1985,(8):609-616
The specific absorption rate (SAR) was measured in over 650 locations in a full-scale model of man exposed in the far and near field of antennas at 350 and 915 MHz. The whole-body average, the body-parts average, and the distributions of the SAR's are compared for three wave polarizations for the far and the near-field exposures. Effects on the energy deposition of the antenna type, gain, and location in the near field are discussed. 相似文献
993.
Roser Canals María del Carmen Llaudy Joan Miquel Canals Fernando Zamora 《European Food Research and Technology》2008,226(5):1183-1190
Several winemaking techniques have been developed to eliminate seeds to prevent the release of high amounts of very astringent
proanthocyanidins, especially when the grapes are unripe. However, there is no scientific information on the effects of this
practice. The aim of this paper is to study how the elimination and addition of seeds influence the colour, phenolic composition
and astringency of red wine. The elimination of around 80% of the seeds led to a significant decrease of colour intensity
and anthocyanin concentration. The addition of seeds originated wines with a greater concentration of total anthocyanin, but
did not significantly affect the wine colour. These wines also presented significantly higher levels of proanthocyanidins,
a greater proportion of epicatechin-3-gallate, a lower mean degree of polymerization, and, in particular, a drastic increase
in astringency. Wines obtained with the elimination of seeds, on the other hand, had exactly the opposite characteristics. 相似文献
994.
Miguel Angelo Faria Eugénia Nunes Maria Beatriz P. P. Oliveira 《European Food Research and Technology》2008,227(3):845-850
Varietal wines are defined as made primarily from a single variety of grape, which is identified on the label. However the
inclusion of other varieties in their production is permitted under defined percentages. The fact that different grape varieties/varietal
wines present far different economical values can attract fraudulent practices. Thus the development of methods, which allow
the quantification of those varieties, is of crucial importance. The first approach to the method for the relative quantification
of must containing two varieties based on microsatellite DNA analysis is presented. Quantification was achieved by densitometry
measurements of the amplification products of the pooled varieties, obtained with loci VVMD6 and VVMD7, after their separation and staining on polyacrilamide gels. We have found that a good correlation between
the proportion of each variety in must and the signal intensity of the alleles are dependent on the variety (varietal effect)
and the microsatellite locus used. The relative quantification of musts can be accomplished by the presented method depending on the presence of overlapping
alleles, and the composition of the varieties and their relative amounts. 相似文献
995.
From 2010 government funding for UK research will be based partly on metrics. One of the key metrics will be citations, with research income and postgraduate student numbers also assessed. While citation metrics seem sensible, there is a serious issue of what topics one researches, the methods used and the way in which a move to the use of citations will induce a change in research behaviour – especially a move to the dull middle ground. This paper investigates the potential impact of such a move on niche areas of IS research – here research on small- and medium-sized enterprises. However, the arguments hold for any new, emerging, or non-mainstream research area. The impacts of citation metrics on publication outlets and research method choice are assessed. 相似文献
996.
Current capabilities of Large-Eddy Simulation (LES) in Eulerian–Lagrangian studies of dispersed flows are limited by the modeling of the Sub-Grid Scale (SGS) turbulence effects on particle dynamics. These effects should be taken into account in order to reproduce accurately the physics of particle dispersion since the LES cut-off filter removes both energy and flow structures from the turbulent flow field. In this paper, we examine the possibility of including explicitly SGS effects by incorporating ad hoc closure models in the Lagrangian equations of particle motion. Specifically, we consider candidate models based on fractal interpolation and approximate deconvolution techniques. Results show that, even when closure models are able to recover the fraction of SGS turbulent kinetic energy for the fluid velocity field (not resolved in LES), prediction of local segregation and, in turn, of near-wall accumulation may still be inaccurate. This failure indicates that reconstructing the correct amount of fluid and particle velocity fluctuations is not enough to reproduce the effect of SGS turbulence on particle near-wall accumulation. 相似文献
997.
Maria Laura Martins‐Costa Rogrio M. Saldanha da Gama 《International journal for numerical methods in engineering》2001,52(10):1047-1067
This work studies an unsaturated flow of a Newtonian fluid through a rigid porous matrix, using a mixture theory approach in its modelling. The mixture consists of three overlapping continuous constituents: a solid (porous medium), a liquid (Newtonian fluid) and an inert gas (to account for the mixture compressibility). A set of two nonlinear partial differential equations describes the problem, which is approximated by means of a Glimm's scheme, combined with an operator splitting technique. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
998.
999.
Patterson Teresa A.; Alvarado Maria C.; Warner Irene T.; Bennett Edward L.; Rosenzweig Mark R. 《Canadian Metallurgical Quarterly》1986,100(6):856
Stages of formation of memory and the roles of different forebrain structures in memory formation were investigated by injecting various agents into the brains of chicks close to the time of peck-avoidance training. With L-glutamate injected bilaterally into the hyperstriatum 5 min pretraining, retention was good 1 min posttraining but significantly impaired at 5 min and each subsequent time point from 10 min to 24 hr. With ouabain, retention declined more slowly, showing significant impairment at 15 min and thereafter. With any of 3 protein synthesis inhibitors, retention was still good 60 min posttraining but significantly impaired at 90 min. The 3 time courses of decline of retention are consistent with hypotheses of 3 sequentially dependent stages of memory formation. It appears that both the medial hyperstriatum and the lateral neostriatum are required for formation of memory. Agents that are specific for a presumed stage of memory formation and whose action is restricted spatially should help reveal the roles of different brain structures in different stages of memory formation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
1000.