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931.
Most artificial neural networks (ANNs) have a fixed topology during learning, and often suffer from a number of shortcomings as a result. Variations of ANNs that use dynamic topologies have shown ability to overcome many of these problems. This paper introduces location-independent transformations (LITs) as a general strategy for implementing distributed feed forward networks that use dynamic topologies (dynamic ANNs) efficiently in parallel hardware. A LIT creates a set of location-independent nodes, where each node computes its part of the network output independent of other nodes, using local information. This type of transformation allows efficient support for adding and deleting nodes dynamically during learning. In particular, this paper presents a LIT that supports both the standard (static) multilayer backpropagation network, and backpropagation with dynamic extensions. The complexity of both learning and execution algorithms is O(q(Nlog M)) for a single pattern, where q is the number of weight layers in the original network, N the number of nodes in the widest node layer in the original network, and M is the number of nodes in the transformed network (which is linear in the number hidden nodes in the original network). This paper extends previous work with 2-weight-layer backpropagation networks. 相似文献
932.
Three volatile ketones, 2-tridecanone, (E)-3-tridecen-2-one and (E)-4-tridecen-2-one were identified in interdigital gland extracts from black-tailed deer,Odocoileus hemionus columbianus. The major compound, (E)-3-tridecen-2-one, inhibited the growth of several species of fungi and grampositive bacteria. The bacterium,Propionibacterium acnes, and the fungus,Trichophyton mentagrophytes required a minimum concentration (MIC) of 12.5 µg/ml and 25 µg/ml, respectively, for inhibition, (E)-3-Tridecen-2-one represents a new class of lipid antibiotics found on animal skin. The second major compound is this secretion, 2-tridecanone, was not active against any of the organisms tested. 相似文献
933.
An adaptive speed control scheme for diesel prime movers is presented. Diesel prime movers are characterized by nonlinear, time-varying parameters including a nonlinear input dead-time variation that introduces an unknown delay between the injection of fuel and the production of engine torque. Such plants are difficult to control by conventional proportional-integral (PI) controllers. It is shown that by assuming the existence of an additional system time constant, an explicit estimate of the plant parameters and dead-time may be obtained. The algorithm converges rapidly. The resulting predictor can be used to set up a k -step ahead predictive controller. Studies that compare the performance of the adaptive scheme to that of a fixed, tuned, PI controller are presented. The algorithm is shown to be flexible enough to operate under a wide range of droop settings and is equally applicable to various operating conditions 相似文献
934.
935.
936.
Four portable carbon dioxide monitors were assessed by a mobile intensive therapy team during interhospital transfer of critically ill patients. Particular attention was paid to practical considerations such as size, battery life and ease of use. All the monitors performed well in terms of accuracy but problems with size and battery life made some less suitable for use outside hospital. 相似文献
937.
IA Hope JM Arnold D McCarroll G Jun AP Krupa R Herbert 《Canadian Metallurgical Quarterly》1998,260(2-3):300-308
Rats were fed on a low fat diet or on high fat diets which included coconut oil, olive oil, safflower oil, evening primrose oil or fish oil as the principal fat source. The level of phosphatidylinositol-4, 5-bisphosphate in spleen lymphocytes was unaffected by diet. However, the fish oil diet significantly decreased the concentration of inositol-1,4,5-trisphosphate in stimulated lymphocytes; this concentration was also reduced following olive oil feeding. Diet did not significantly affect the level of phospholipase C-gamma1 in spleen lymphocytes but the tyrosine phosphorylation state of this enzyme in stimulated lymphocytes, as well as that of a range of other proteins, was decreased following feeding the fish oil and, to a lesser extent, the olive oil diets. It is concluded that fish oil feeding appears to result in inhibition of one or more tyrosine kinases. 相似文献
938.
C. F. A. Hope 《Journal of the Institute of Brewing》1987,93(3):213-215
Cinnamic acid (100 μg ml?1) incorporated in a solid medium was found to inhibit the growth of brewing strains (Pof?) of yeast while permitting the growth of Pof+ wild yeast contaminants. Typically, colonies of Saccharomyces cerevisiae var. diastaticus (Pof+) mixed with brewing yeast (S. cerevisiae NCYC 240) were visible after 5d incubation at 25°C. The incubation time required to detect a selection of brewery wild yeast isolates was found to vary from 3–12 d. 相似文献
939.
Ghaemi FT 《Applied optics》2011,50(26):5108-5114
Cameras built for space exploration are required to meet stringent environmental conditions, such as thermal and dynamic loads for both the optics (camera lens) and imaging electronics. On a multitude of spaceborne imaging instruments, optical elements are supported in their mounts via an elastomeric bonding approach using a room temperature vulcanizing silicone as the bonding agent. Employing this integration method, we achieved element-to-element alignment, measured as the total indicated runout, using a high-precision contact probe to be on the order of half a wavelength of He-Ne laser light, or 0.3?μm, on the Malin Space Science Systems lenses for the Mars Science Laboratory (MSL) cameras. This is a higher precision than the current industry state-of-the-art, and it was achieved for the very challenging small diameter lens elements. This paper describes the design philosophy, implementation, and integration method that resulted in achieving this level of precision for interelement alignment. The results are based on actual measurements that were made during the process of building the MSL rover's science camera lenses, namely Mastcams, the Mars Hand Lens Imager, and the Mars Descent Imager. The optical designs of these cameras lenses are described in detail in [Opt. Eng.48, 103002 (2009)], while further information on the four science cameras can be found at http://www.msss.com. 相似文献
940.
Tony JosephMailadil Thomas Sebastian 《Materials Letters》2011,65(5):891-893
Alkaline earth orthosilicates M2SiO4 (M=Ba, Sr, Ca) ceramics were prepared by solid state ceramic route and their microwave dielectric properties were investigated. M2SiO4 ceramics have εr in the range 8.5-13. At microwave frequencies, the Qu × f obtained were 17,900 GHz, 19,100 GHz and 26,100 GHz for Ba2SiO4, Sr2SiO4 and Ca2SiO4 respectively. The τf of Ba2SiO4 was − 17 ppm/°C, whereas Sr2SiO4 and Ca2SiO4 exhibited high values of τf, − 205 ppm/°C and − 89 ppm/°C respectively. The coefficient of thermal expansion (αl) of the orthosilicates was also studied. 相似文献