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131.
Early Herbivore Alert: Insect Eggs Induce Plant Defense 总被引:14,自引:5,他引:9
Plants are able to “notice” insect egg deposition and to respond by activating direct and indirect defenses. An overview of these defenses and the underlying mechanisms is given from a tritrophic perspective. First, the interface between plant and eggs is addressed with respect to the mode of attachment of eggs on the plant surface. It is elucidated which plant cells might respond to components from insect eggs or the egg deposition. The scarce knowledge on the elicitors associated with the eggs or the egg-laying female is outlined. Since endosymbiotic microorganisms are often present on the eggs, and microorganisms are also abundant on the leaf surface, the role of these hidden players for eliciting oviposition-induced plant responses is considered. Furthermore, the question of which physiological and molecular processes are induced within the plant in response to egg deposition is addressed. Second, studies on the response of the herbivorous insect to oviposition-induced plant defenses are outlined. Third, the importance of oviposition-induced plant volatiles and contact cues for host and prey location of parasitoids and predators is discussed in the context of other informative chemicals used by carnivores when searching for food. Finally, physiological and ecological costs of oviposition-induced plant responses are addressed. 相似文献
132.
A. V. Shlyakhtina S. N. Savvin A. V. Levchenko A. V. Knotko Petra Fedtke Andreas Busch Torsten Barfels Marion Wienecke L. G. Shcherbakova 《Journal of Electroceramics》2010,24(4):300-307
The electrical conductivity of new solid electrolytes Eu2.096Hf1.904O6.952 and Gd2Hf2O7 have been compared with those for different pyrochlores including titanates and zirconates Ln2+xМ2−xO7−δ (Ln = Sm-Lu; M = Ti, Zr; x = 0−0.81). Impedance spectroscopy data demonstrate that Eu2.096Hf1.904O6.952 and Gd2Hf2O7 synthesized from mechanically activated oxides have high ionic conductivity, comparable to that of their zirconate analogues.
The bulk and grain-boundary components of conductivity in Sm2.096Hf1.904O6.952 (Тsynth = 1600oС), Eu2.096Hf1.904O6.952 and Gd2Hf2O7 (Тsynth = 1670oС) have been determined. The highest bulk conductivity is offered by the disordered pyrochlores prepared at 1600oC
and 1670oC: ~1.5 × 10−4 S/cm for Sm2.096Hf1.904O6.952, 5 × 10−3 S/cm for Eu2.096Hf1.904O6.952 and 3 × 10−3 S/cm for Gd2Hf2O7 at 780oС, respectively. The conductivity of the fluorite-like phases at the phase boundaries of the Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x ~ 0.286) solid solutions, as well as that of the high-temperature fluorite-like phases Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0−0.286), is lower than the conductivity of the disordered pyrochlores Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0−0.096). 相似文献
133.
Bastian?RistauEmail author Torsten?Limberg Gerhard?Fettweis 《Journal of Signal Processing Systems》2009,57(1):45-56
The computational demand of signal processing algorithms is rising continuously. Heterogeneous embedded multiprocessor systems-on-chips
are one solution to satisfy this demand. But to be able to take advantage of these systems, new strategies are required to
map applications to such a system and to evaluate the systems performance at a very early design stage. We will present a
framework for static, analytical, bottom-up temporal and spatial mapping of applications to MPSoCs based on packing. This
mapping framework allows easy performance evaluation and design space exploration of heterogeneous systems on chip.
相似文献
Gerhard FettweisEmail: |
134.
A novel concept for the measurement of proton transport properties and electrode kinetics in proton exchange membrane fuel cells (PEMFC) is presented. The “proton pump” is essentially a fuel cell operated with pure nitrogen or very low hydrogen partial pressure instead of oxygen-containing gas on the cathode side, avoiding the complicated electrode kinetics of oxygen reduction. In this first study using this concept, we investigated the proton transport in high temperature PEMFC based on polybenzimidazole (PBI)/phosphoric acid membranes. The impedance spectra of the proton pump allow the clear distinction between anode and cathode kinetics and proton transport in the membrane. Identifying and analyzing the contribution of the anodic processes in the impedance spectra enabled the quantitative investigation of anode kinetics based on the Butler-Volmer equation. The proton transport was investigated in more detail in the current saturation region, where proton transport turned out to be the limiting process in case of sufficient H2 supply at the anode. The maximum proton transport capacity of the PBI/phosphoric acid membrane was found to be comparable to those of Nafion® membranes. 相似文献
135.
An vielen Stellen im Tragwerk herrschen mehraxiale Spannungszustände. Ob sich die Tragfähigkeit von Hochleistungsleichtbetonen unter mehraxialer Druckbeanspruchung ebenso erhöht wie bei Normalbetonen, wurde in zwei‐ und dreiaxialen Tests untersucht. Es wurde ein Bruchkriterium für Leichtbetone abgeleitet und Parallelen und Unterschiede zu Normalbeton aufgezeigt. High Performance Lightweight Aggregate Concrete under Multiaxial Compression There are multiaxial stress conditions at many points in a structure. Whether the strength of high performance lightweight concrete under multiaxial compression increases as well as the strength of normal concrete, was verified in bi‐ and triaxial tests. A failure criterion for lightweight concrete was derived and analogies and differences to normal oncrete were pointed out. 相似文献
136.
Christoph Koepple Zizi Zhou Lena Huber Matthias Schulte Kjestine Schmidt Torsten Gloe Ulrich Kneser Volker Jürgen Schmidt Cor de Wit 《International journal of molecular sciences》2021,22(14)
Connexins (Cx) form gap junctions (GJ) and allow for intercellular communication. However, these proteins also modulate gene expression, growth, and cell migration. The downregulation of Cx43 impairs endothelial cell migration and angiogenetic potential. Conversely, endothelial Cx43 expression is upregulated in an in vivo angiogenesis model relying on hemodynamic forces. We studied the effects of Cx43 expression on tube formation and proliferation in HUVECs and examined its dependency on GJ communication. Expectedly, intercellular communication assessed by dye transfer was linked to Cx43 expression levels in HUVECs and was sensitive to a GJ blockade by the Cx43 mimetic peptide Gap27. The proliferation of HUVECs was not affected by Cx43 overexpression using Cx43 cDNA transfection, siRNA-mediated knockdown of Cx43, or the inhibition of GJ compared to the controls (transfection of an empty vector, scrambled siRNA, and the solvent). In contrast, endothelial tube and sprout formation in HUVECs was minimized after Cx43 knockdown and significantly enhanced after Cx43 overexpression. This was not affected by a GJ blockade (Gap27). We conclude that Cx43 expression positively modulates the angiogenic potential of endothelial cells independent of GJ communication. Since proliferation remained unaffected, we suggest that Cx43 protein may modulate endothelial cell migration, thereby supporting angiogenesis. The modulation of Cx43 expression may represent an exploitable principle for angiogenesis induction in clinical therapy. 相似文献
137.
The hygrothermal effect of inside and outside building envelope surfaces. In the past the protection of building constructions under outdoor and indoor climate conditions was one of the most important subjects building physics. Nowadays the energy balance and the hygrothermal performance of building envelopes are current topics. This paper deals with the coupled heat and moisture transfer on the internal and external envelope surfaces. By means of numerical simulation and laboratory investigation the influence of the internal surface of exterior walls on the indoor air humidity is demonstrated. The influence of evaporation cooling on the energy transfer in winter time and during the warm season requires investigations on dewing and driving. It depends on the hygroscopic parameters of the outside wall coating. The effect of infrared reflecting coating is determined. It is shown in which way heat sources integrated in exterior walls could be a possibility to avoid microbiological growth on building envelopes. 相似文献
138.
Journal of Applied Electrochemistry - Large area MoS2 ultra-thin film deposition is one of the big challenges in the recent years. Electrodeposition provides an opportunity to grow such ultra-thin... 相似文献
139.
Reza Mirzaeitalarposhti Michael Scott Demyan Frank Rasche Maxim Poltoradnev Georg Cadisch Torsten Müller 《Nutrient Cycling in Agroecosystems》2015,102(2):265-283
Development of spectroscopic prediction models via partial least squares regression (PLSR) suggests that model performance is highly affected by means of calibration and nature of the dataset. This study compares the predictive performance of PLSR models obtained by cross-validation and independent validation to quantify physico-chemical soil properties from their mid-infrared diffuse reflectance Fourier transform spectra (midDRIFTS) across two contrasting regions, Kraichgau (K) and Swabian Alb (SA), in Southwest Germany. We evaluated the capability of midDRIFTS-PLSR models for predicting total carbon (TC), organic carbon (TOC), inorganic carbon (TIC), nitrogen (TN), mineral N (Nmin), C:N ratio, hot water extractable C and N (CHWE, NHWE), microbial biomass C and N (Cmic, Nmic), pH, bulk density, and clay, silt and sand contents of 126 soil samples. Based on calibrated models, most soil properties were predicted successfully using either calibration approach with residual prediction deviations ≥3 and R2 > 0.9, except for Nmin, C/N ratio, pH, bulk density and sand. However, predictive performance of generic independent validation derived models (GIC) of test set was considerably higher than generic cross-validation models. Validation using GIC models gave relatively the same predictive performance with those obtained in calibration except for Nmin. Validation of region specific cross-validated models, however, resulted in successful predictions only for TC, TIC, TOC and TN in SA and TC and TIC and TOC in K. Our results show the superiority of independent validation over both generic and region specific cross-validation as a robust tool for predicting soil properties without further laboratory measurements. 相似文献
140.
Sophie Bresch Björn Mieller Daniela Schönauer-Kamin Ralf Moos Timmy Reimann Fabien Giovannelli Torsten Rabe 《Journal of the American Ceramic Society》2021,104(2):917-927
Calcium cobaltite Ca3Co4O9, abbreviated Co349, is a promising thermoelectric material for high-temperature applications in air. Its anisotropic properties can be assigned to polycrystalline parts by texturing. Tape casting and pressure-assisted sintering (PAS) are a possible future way for a cost-effective mass-production of thermoelectric generators. This study examines the influence of pressure and dwell time during PAS at 900°C of tape-cast Co349 on texture and thermoelectric properties. Tape casting aligns lentoid Co349. PAS results in a textured Co349 microstructure with the thermoelectrically favorable ab-direction perpendicular to the pressing direction. By pressure variation during sintering, the microstructure of Co349 can be tailored either toward a maximum figure of merit as required for energy harvesting or toward a maximum power factor as required for energy harvesting. Moderate pressure of 2.5 MPa results in 25% porosity and a textured microstructure with a figure of merit of 0.13 at 700°C, two times higher than the dry-pressed, pressureless-sintered reference. A pressure of 7.5 MPa leads to 94% density and a high power factor of 326 µW/mK2 at 800°C, which is 11 times higher than the dry-pressed reference (30 MPa) from the same powder. 相似文献