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991.
A study of bending deformations of sandwich plates using a layerwise theory of laminated or sandwich plates is presented. The analysis is based on a wavelet collocation technique to produce highly accurate results. Numerical results for symmetric laminated composite and sandwich plates are presented and discussed. 相似文献
992.
Raphael Pfattner Marta Mas‐Torrent Ivano Bilotti Aldo Brillante Silvia Milita Fabiola Liscio Fabio Biscarini Tomasz Marszalek Jacek Ulanski Andrzej Nosal Maciej Gazicki‐Lipman Michael Leufgen Georg Schmidt Laurens W. Molenkamp Vladimir Laukhin Jaume Veciana Concepció Rovira 《Advanced materials (Deerfield Beach, Fla.)》2010,22(37):4198-4203
993.
994.
Silvia Orsi Daniela Guarnieri Paolo A. Netti 《Journal of materials science. Materials in medicine》2010,21(3):1013-1020
The ability to genetically modify cells seeded inside synthetic hydrogel scaffolds offers a suitable approach to induce and
control tissue repair and regeneration guiding cell fate. In fact the transfected cells can act as local in vivo bioreactor,
secreting plasmid encoded proteins that augment tissue regeneration processes. We have realized a DNA bioactivated high porous
poly(ethylene glycol) (PEG) matrix by polyethyleneimine (PEI)/DNA complexes adsorption. As the design of the microarchitectural
features of a scaffold also contributes to promote and influence cell fate, we appropriately designed the inner structure
of gene activated PEG hydrogels by gelatine microparticles templating. Microarchitectural properties of the scaffold were
analysed by scanning electron microscopy. 3D cell migration and transfection were monitored through time-lapse videomicroscopy
and confocal laser scanning microscopy. 相似文献
995.
M. Ángeles Gil M. Teresa López-García M. Asunción Lubiano Manuel Montenegro 《TEST》2001,10(1):183-201
In this paper we develop regression and corrclation analyses of a certain general linear relation between two random elements
whose values are non-empty compact intervals. To this purpose, we firstly extend the least-squares method to deal with the
involved random elements on the basis of a generalized metric defined on the space of the considered intervals. As a complementary
study, a coefficient quantifying the strength of the linear relation between the two random elements is also presented, and
a discussion of the extreme values for this measure is presented. A real-life example illustrates these studies.
Research partially supported by DGESIC/MEC Grants No. DGE-99-PB98-1534 and No. DGE-98-PB97-1282. 相似文献
996.
Roberto Cárcoba Teresa Delgado A. Rodríguez 《European Food Research and Technology》2000,211(2):141-146
Lactococcus lactis ssp. lactis IPLA 947, L. lactis ssp. lactis biovar. diacetylactis IPLA 838 and Leuconostoc citreum IPLA 616 and designed for Afuega'l Pitu cheese manufacture from pasteurized milk was assayed in cow's and ewe's milk, and
in mixtures containing 10% and 20% ewe's milk in cow's milk. The evolution of microbial counts, pH, titratable acidity, organic
acids and volatile compounds production throughout the incubation period was determined. The use of ewe's milk as a culture
medium increased the metabolic activity of the starter culture reflected in a higher lactose consumption, significantly higher
acidity and some carbon source-derived organic acids and volatile compounds production, as well as in slightly higher starter
strains growth, although the latter was not statistically significant. Thus, it is suggested that ewe's milk or mixtures of
ewe's with cow's milk can be satisfactorily used in the manufacture of this traditional cheese.
Received: 27 August 1999 相似文献
997.
Mrcia Regina de Moura Fauze Ahmad Aouada Silvia Luciana Favaro Eduardo Radovanovic Adley Forti Rubira Edvani C. Muniz 《Materials science & engineering. C, Materials for biological applications》2009,29(8):2319-2325
The synthesis of thermosensitive Interpenetrating Polymer Network (IPN) hydrogels and the release of Bovine Serum Albumin (BSA) from the hydrogels were reported. The hydrogels, constituted of poly(N-isopropyl acrylamide) PNIPAAm network interpenetrated in alginate–Ca2+ network, were synthesized in a two-stepped process. In the first step, PNIPAAm network was synthesized from an aqueous solution containing N-isopropyl acrylamide (NIPAAm) monomers and N,N′-methylene-bis-acrylamide (MBAAm) co-monomers, and sodium alginate (SA) (1 or 2% w/v). The concentration of NIPAAm monomers in the hydrogel-forming solution was always 2.5, 5.0 or 10.0% (w/v). In the second step, alginate–Ca2+ networks were formed by immersion of the membrane, obtained on the first step, in a 1.0% (w/v) aqueous calcium chloride. The IPN hydrogels were characterized as a function of temperature (from 25 to 45 °C) through the following measurements: drop water contact angle (DWCA), compression elastic modulus (E) and cross-linking density (νe). The morphology was investigated using scanning electronic microscopy (SEM). In vitro release of BSA from the hydrogels was monitored by UV–Vis spectroscopy at 22 °C and 37 °C. DWCA results showed a decrease in the hydrogel hydrophilicity when the temperature and/or the PNIPAAm amount on hydrogels were increased. PNIPAAm-loader hydrogels are more compacted and presented elevated rigidity, mainly above 35 °C. This trend was attributed to the collapsing of PNIPAAm chains as the hydrogels were warmed above its Lower Critical Solution Temperature (LCST), which in aqueous solution is ca. 32–33 °C. The amount of BSA released from the alginate–Ca2+/PNIPAAm hydrogels changes inversely to both amount of PNIPAAm and temperature. The transport of BSA from the hydrogels was evaluated through a conventional model. In the lesser-compacted hydrogels the release occurs mostly by diffusion. In the more compacted ones the chain relaxation contributes to the BSA release. Thus, the alginate–Ca2+/PNIPAAm IPN-typed matrixes may be considered as smart hydrogels for the release of BSA, because the amount and rate of BSA released may be tailored by both the NIPAAm concentration in the hydrogel-forming solution and the control of temperature of hydrogel. 相似文献
998.
Kinetics of para-nitrophenol and chemical oxygen demand removal from synthetic wastewater in an anaerobic migrating blanket reactor 总被引:1,自引:0,他引:1
A laboratory scale anaerobic migrating blanket reactor (AMBR) was operated at different HRTs (1-10.38 days) in order to determine the para-nitrophenol (p-NP) and COD removal kinetic constants. The reactor was fed with 40 mg L(-1)p-NP and 3000 mg L(-1) glucose-COD. Modified Stover-Kincannon and Grau second-order kinetic models were applied to the experimental data. The predicted p-NP and COD concentrations were calculated using the kinetic constants. It was found that these data were in better agreement with the observed ones in the modified Stover-Kincannon compared to Grau second-order model. The kinetic constants calculated according to Stover-Kincannon model are as follows: the saturation value constant (K(B)) and maximum utilization rate constants (R(max)) were found as 31.55 g CODL(-1)day(-1), 29.49 g CODL(-1)day(-1) for COD removal and 0.428 g p-NPL(-1)day(-1), 0.407 g p-NPL(-1)day(-1) for p-NP removal, respectively (R(2)=1). The values of (a) and (b) were found to be 0.096 day and 1.071 (dimensionless) with high correlation coefficients of R(2)=0.85 for COD removal. Kinetic constants for specific gas production rate were evaluated using modified Stover-Kincannon, Van der Meer and Heerrtjes and Chen and Hasminoto models. It was shown that Stover-Kincannon model is more appropriate for calculating the effluent COD, p-NP concentrations in AMBR compared to the other models. The maximum specific biogas production rate, G(max), and proportionality constant, G(B), were found to be 1666.7 mL L(-1) day(-1) and 2.83 (dimensionless), respectively in modified Stover-Kincannon gas model. The bacteria had low Haldane inhibition constants (K(ID)=14 and 23 mg L(-1)) for p-NP concentrations higher than 40 mg L(-1) while the half velocity constant (K(s)) increased from 10 to 60 and 118 mg L(-1) with increasing p-NP concentrations from 40 to 85 and 125 mg L(-1). 相似文献
999.
1000.
Rafael F. Cossiello Ali Cirpan Frank E. Karasz Leni Akcelrud Teresa D.Z. Atvars 《Synthetic Metals》2008,158(6):219-225
This work reports the electroluminescence of poly[2-methoxy-5(2′-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) and poly(styrene-co-acrylic acid-co-1-pyrenylmethyl methacrylate) (SAA) blends in ratios from 0 to 100 wt.% in mass of MEH-PPV. The styrene-co-acrylic copolymer was synthesized with 3 mol% of acrylic acid units to simultaneously enhance blend miscibility and charge transport in MEH-PPV. The morphology was studied using epifluorescence microscopy and scanning electron microscopy in which the pyrenyl-labeled copolymer is used to enhance microscopic contrast. Device performances were compared: those using MEH-PPV have a turn-on voltage of 3.5 V, luminance of 500 cd/m2 and current density of 430 mA/cm2 at 5 V, while MEH-PPV blended with 50 wt.% styrene–acrylic copolymer showed a turn-on voltage of 2.5 V, a luminance of 2300 cd/A and a current density of 640 mA/cm2 at 5 V. 相似文献