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181.
Administration of footshock (500-ms duration, 0.2–2.4 mA) increased the amplitude of the startle reflex for a long time after its presentation. The effect occurred with a single footshock, although its magnitude and consistency across animals were greater with 5 or 10 footshocks presented 1/s. The facilitatory effect came on within 2–4 min with a 0.6-mA shock, peaking in about 10 min and then dissipating over the next 40 min. Stronger shocks also increased startle, but with a more delayed onset of facilitation (8–20 min). Footshocks increased startle in rats not previously given startle-eliciting stimuli, indicating sensitization rather than dishabituation. The facilitatory effect may not be attributable to a rapid conditioning to the experimental context, because a change in lighting conditions from shock presentation to testing did not attenuate shock sensitization. This excitatory effect of shock on startle may represent the unconditioned effect of shock that can become associated with a neutral stimulus to support classical fear conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
182.
John M Veranth Erin G Kaser Martha M Veranth Michael Koch Garold S Yost 《Particle and fibre toxicology》2007,4(1):2-18
Background
The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-α, and VOSO4. 相似文献183.
184.
Mass transport in wood during drying can have different mechanisms at different periods of drying. Depending on the current moisture content (MC) and the structure of the wood, the driving forces for the mass transport are essentially different. Above the fiber saturation point (FSP), the lumens are partially saturated and the transport of liquid (free) water occurs as a consequence of capillary action. On the other hand, below the FSP, bound water within the cell walls is conveyed by diffusion, and water vapor in the lumens moves under influence of pressures gradient. Based on these considerations, a unified model is presented that takes into account the transport of the different moisture phases. Simulation of the drying of a Norway spruce sample at 50°C from about 135 to 7% MC is carried out using the finite element method (FEM). Comparison between the simulated average MC and the experimental observations obtained from X-ray computed tomography (CT) shows reasonable agreement. Possible simplifications in the model are briefly discussed as well as some aspects of the numerical implementation. Finally, the influence of absolute permeability on the average MC is studied. 相似文献
185.
Michael Brady 《Energy》1985,10(10):1113-1118
Current energy policies have severely eroded the earth's natural atmospheric waste-receptor capacity. Present acid rain concentrations may require a switch to an alternative energy-resource emphasis. This policy recommendation follows directly from a deductive control theory demonstration which shows that, if fossil-fuel use is continued at present rates, then there is an ever-increasing risk of a man-made environmental crisis of uncertain nature and scope. 相似文献
186.
Michael Maiwald Hongping Li Thorsten Schnabel Kay Braun Hans Hasse 《The Journal of Supercritical Fluids》2007,43(2):267
On-line NMR spectroscopy can beneficially be applied to studies of supercritical and near-critical fluids as an alternative to optical spectroscopy. Up to now high pressure NMR experiments are predominantly accomplished using custom made NMR batch reactors. The authors present a novel high pressure cell with displacement plunger for on-line NMR experiments on compressible fluids which can be used in conjunction with commercially available SCF NMR flow probes. The on-line technique offers advantages compared to stopped flow techniques such as enhanced control of mixture composition and reaction parameters as well as the facility of engagement into the reaction. The new apparatus is used for NMR studies on hydrogen bonding of methanol in near critical and supercritical carbon dioxide up to 403 K and 35 MPa for which data on the chemical shift of the hydroxyl group and methyl group are reported and interpreted. 相似文献
187.
Estrogenic personal care products in a greywater reuse system. 总被引:1,自引:0,他引:1
H R Andersen M Lundsbye H V Wedel E Eriksson A Ledin 《Water science and technology》2007,56(12):45-49
The occurrence and fate of parabens in a greywater system was assessed. The potential for removal of residual paraben concentrations in effluent greywater with chlorine dioxide was also investigated. The influent to the greywater plant was characterised by considerable variation, with concentrations from below the detection limit to 40 microg/L and the five commonly used parabens in consumer products were frequently detected. After the biological treatment only two paraben were detected with concentration from 65-120 ng/L. Chlorine dioxide treatment of the biologically treated effluent with dosages down to 0.75 mg/L resulted in more than 97% reduction of all parabens. Formation of the by-product chloroform was insignificant from the chlorine dioxide treatment. 相似文献
188.
189.
Burgess Curt; Tanenhaus Michael K.; Seidenberg Mark S. 《Canadian Metallurgical Quarterly》1989,15(4):620
To eliminate potential "backward" priming effects, S. Glucksberg et al (see record 1986-29080-001) introduced a variant of the cross-modal lexical priming task in which subjects made lexical decisions to nonword targets that were modeled on a word related to either the contextually biased or unbiased sense of an ambiguous word. Lexical decisions to nonwords were longer than controls only when the nonword was related to the contextually biased sense of the ambiguous word, leading Glucksberg et al to conclude that context does constrain lexical access and that the multiple access pattern observed in previous studies was probably an artifact of backward priming. We did not find nonword interference when the nonword targets used by Glucksberg et al were preceded by semantically related ambiguous or unambiguous word primes. However, we did replicate their sentence context results when the ambiguous words were removed from the sentences. We conclude that the interference obtained by Glucksberg et al is due to postlexical judgments of the congruence of the sentence context and the target, not to context constraining lexical access. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
190.
This article describes a circuit model for infinitesimally thin inductive strips centered in homogeneous finline. The model is valid for 0.1 ≤ W/b ≤ 1.0, 0.01 ≤ T/a, and 0.4 ≤ b/a ≤ 0.5 when frequency is in the normal operating band for the rectangular waveguide shield. The error is less than 2.5%. 相似文献