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101.
On the removal of shadows from images   总被引:3,自引:0,他引:3  
This paper is concerned with the derivation of a progression of shadow-free image representations. First, we show that adopting certain assumptions about lights and cameras leads to a 1D, gray-scale image representation which is illuminant invariant at each image pixel. We show that as a consequence, images represented in this form are shadow-free. We then extend this 1D representation to an equivalent 2D, chromaticity representation. We show that in this 2D representation, it is possible to relight all the image pixels in the same way, effectively deriving a 2D image representation which is additionally shadow-free. Finally, we show how to recover a 3D, full color shadow-free image representation by first (with the help of the 2D representation) identifying shadow edges. We then remove shadow edges from the edge-map of the original image by edge in-painting and we propose a method to reintegrate this thresholded edge map, thus deriving the sought-after 3D shadow-free image.  相似文献   
102.
Genetic science, animal exploitation, and the challenge for democracy   总被引:1,自引:0,他引:1  
As the debates over cloning and stem cell research indicate, issues raised by biotechnology combine research into the genetic sciences, perspectives and contexts articulated by the social sciences, and the ethical and anthropological concerns of philosophy. Consequently, I argue that intervening in the debates over biotechnology requires supra-disciplinary critical philosophy and social theory to illuminate the problems and their stakes. In addition, debates over cloning and stem cell research raise exceptionally important challenges to bioethics and a democratic politics of communication.
Steven BestEmail:
  相似文献   
103.
In many applications, volumetric data sets are examined by displaying isosurfaces, surfaces where the data, or some function of the data, takes on a given value. Interactive applications typically use local lighting models to render such surfaces. This work introduces a method to precompute or lazily compute global illumination to improve interactive isosurface renderings. The precompiled illumination resides in a separate volume and includes direct light, shadows, and intersections. Using this volume, interactive globally illuminated renderings of isosurfaces become feasible while still allowing dynamic manipulation of lighting, viewpoint and isovalue.  相似文献   
104.
This paper addresses manufacturing research involving advances in material process control. The research objective has been to develop intelligent, self-directed and self-improving control systems which enablein situ (real-time) control path generation based on both product (material behaviour) and processing (control agent) feedback. A product-process control philosophy which emphasises product quality is described together with a generic architecture for representing product and process knowledge.Specific details are presented involving the development and application of a self-directed and self-improving material processing system for molecular beam epitaxy of gallium arsenide wafers. Special emphasis is given to the development of a neural model for self-improving control as well as future research directions.  相似文献   
105.
Companies have introduced innovative organizational structures to deal with rapidity of change, the globalization of markets, and expectations for increased quality and customer service. During this process, many have discovered that the interaction between IT and business units is key to success. This article presents the results of a pilot study that examined the structure of this interaction in eight Fortune 500 manufacturing companies. It answers the questions: What prototypes describe the interaction between IT corporate business units? What outcomes are associated with the various prototypes? What are the implications of these models of structure for the effective delivery of IT services?  相似文献   
106.
107.
One unidirectional and two laminated 6061-0 A-B composite plates were tested under various cyclic loading conditions. Three types of material response to cyclic loading were identified; No evidence of damage at relatively low cyclic loads, damage accumulation caused primarily by growth of long matrix cracks parallel to the fibers in off-axis layers at higher loads, and sudden localized failure of the fibers. Quantitative analysis of the results shows that the extent of internal damage, demonstrated by a reduction in axial elastic modulus, depends on the applied stress range and is independent of mean stress. The stress range at which damage first starts to appear coincides with the shakedown range of the laminate.
Résumé On a testé sous des conditions de contrainte cyclique variable des plaques constituées d'une part par des alliages 6061-0 A-B unidirectionnels et d'autre part du même alliage composite bilaminé. On a identifié trois types de réponse du matériau aux contraintes cycliques, à savoir la non-évidence d'un dommage pour des cycles de charge à faible amplitude relative, une accumulation du dommage causé principalement par la croissance de longues fissures matricielles parallèles aux fibres dans les couches éloignées du plan médian à des contraintes plus élevées, et une fissure soudainement localisée des fibres. L'analyse quantitative des résultats montre que 1'extension du dommage interne telle qu'elle est dóntree par une réduction du module axial d'élasticité, dépend de l'amplitude des contraintes appliquées et est indéndante de la contrainte moyenne. L'amplitude de contrainte auquelle un dommage commence à apparaître coíncide avec l'amplitude de l'adaptation plastique du laminé telle qu'établie par le théorème de Melan.
  相似文献   
108.
Improved Synthesis and Physicochemical Properties of Alkoxylated Inulin   总被引:1,自引:0,他引:1  
Inulin, a polydisperse reserve polysaccharide extracted from chicory, has been modified by alkoxylation in a water-free medium using a basic catalyst. The reaction of inulin with ethylene oxide, as well as propylene oxide, was performed in an organic solvent, N-methylpyrrolidinone, with triethylamine as basic catalyst in almost quantitative yields. The reaction resulted in a range of products with very specific properties such as highly increased water solubility, moderate surface activities and very high cloud points in electrolyte media.  相似文献   
109.
Many developing world cities have seen the emergence of informal markets where private tanker truck operators transport water extracted from peri-urban wells to urban consumers. This study adopted a systems-modelling approach to analyzing the informal tanker market in India. The results indicate that the demand for tanker supply was caused by lack of groundwater availability in private wells as well as unreliable piped supply. The study shows that two groundwater factors are relevant: depth to water and aquifer productivity. Together, these could explain the difference in spatial, temporal and consumer-specific variations in tanker dependence.  相似文献   
110.
Six offshore stations in southeastern Lake Michigan were sampled during a pre quagga mussel Dreissena rostriformis bugensis period (1995–2000) and a post quagga mussel period (2007–2011). Chlorophyll a fluorescence profiles were used to characterize chlorophyll a concentrations during early (June–July) and late (August–September) summer stratification. During the early summer period the average whole water column chlorophyll a, the deep chlorophyll maximum, and the size of deep chlorophyll layer decreased 50%, 55%, and 92%, respectively, between 1995–2000 and 2007–2011. By contrast, in late summer there were no changes in these metrics between periods. Surface mixed layer chlorophyll a in early and late summer did not differ between time periods. On the other hand, chlorophyll a in the near bottom zone (bottom 20 m) declined 63% and 54% between 1995–2000 and 2007–2011 in early and late summer respectively. Changes in total phosphorus between 1995–2000 and 2007–2011 were less dramatic, with declines of 22–27% in early summer and 11–30% in late summer. Changes in the chlorophyll a conditions were attributed to dreissenid mussels which reduced material available from the spring bloom and disrupted the horizontal transport of nutrients to the offshore. Although light availability increased (i.e., increased secchi depths), reduced nutrient availability and spring diatom abundance resulted in a much smaller deep chlorophyll layer in 2007–2011.  相似文献   
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