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11.
Abstract The SelfSpell programs provide a multi-media environment for dyslexic children which uses synthesised speech to augment the written text. In earlier research we established that by encouraging users to enter a rule to help them remember how to spell each word, SelfSpell was very effective in improving spelling ability. The evaluation study reported here confirmed the efficacy of the rule-based approach using a group of 11-year-old dyslexic children with severe impairments in spelling. Of particular theoretical significance, however, was the finding that use of a mastery learning technique for learning spellings was just as effective as the rule-based approach. These findings are interpreted in the light of Frith's influential framework for the development of reading and spelling ability. It is suggested that the multimedia presentation approach may provide a uniquely effective method for helping dyslexic children to acquire the 'alphabetic' stage of linguistic processing. 相似文献
12.
The behavior during creep in shear of eutectic indium-tin joints on copper and nickel substrates was examined in order to
determine the effect of creep deformation on the microstructure of the alloy. Primary creep was absent in all the samples
tested. The stress exponent at 20° C was much higher for samples on nickel than for those on copper, indicating a different
creep deformation mechanism. Also, the microstructure within the indium-tin joints differed significantly with a change of
substrate. Samples with a nickel substrate showed a colony microstructure that was not observed in those with a copper substrate.
Thus, eutectic morphology is important in determining deformation mechanism during creep. The microstructure within the joints
in tested and untested regions of the samples was effectively the same. This is quite distinct from the behavior of eutectic
lead-tin observed in previous work. Lead-tin formed a recrystallized band of material along a region of concentrated shear
deformation. While the deformation pattern in the indium-tin samples appeared to be the same as for lead-tin, the microstructural
changes did not occur. This implies that the behavior observed in lead-tin is not universal to eutectic alloys. 相似文献
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Calculated hardenability for improved consistency of properties in heat treatable engineering steels
W. T. Cook P. F. Morris L Woollard 《Journal of Materials Engineering and Performance》1997,6(4):443-448
Hardenability is one of the most important parameters controlling the heat treated properties of engineering steels. It affects
the consistency of response for microstructure, hardness, strength, toughness, and dimensional change (distortion). This study
illustrates that a major benefit of controlling hardenability is improving the consistency of dimensional distortion resulting
from heat treatment. To facilitate the supply of steels to hardenability limits, especially restricted hardenability, a new
technique was developed for the prediction of Jominy hardenability from chemical composition. The technique, termed the “Database
Method,” uses measured Jominy hardenability and chemical composition data, contained in a database, to calculate the hardenability
for a query composition. Using up to ten known steels, selected from the database with compositions closely matching that
of the query steel, a small adjustment is made to the measured hardenability of each known steel allowing for the small difference
in composition between the query and chosen steel. The final calculated result for the query steel is taken as the average
of the various estimates. The basis of the Database Method is explained, and the advantages are illustrated for selecting
engineering grades. 相似文献
17.
An explicit finite difference scheme is proposed for nonlinear convective problems. The procedure is applied to a nonlinear convective diffusion problem with a nonlinear boundary condition. It is shown that the nonlinear boundary condition may be treated directly without linearization which has to be carried out in the implicit method to avoid a nonlinear system of algebraic equations. The explicit procedure is more direct and less cumbersome than the implicit procedure and the answers are in excellent agreement with those of the implicit method. 相似文献
18.
The VIrtual Planning Test (VIP) was developed to investigate the planning and organisational abilities of 25 patients with frontal lobe neurosurgical lesions, comparing their performance with 25 matched control subjects. The task, presented in the form of a board game, simulates planning and execution of a set of target activities that have to take place over a four day period, involving those that are either preparatory for a fictional "trip" abroad, or those that relate to the subject's current environment (context). The frontal lobe patients were impaired overall, tending to select inappropriate activities associated with their current context and showing greater impairment on subtasks requiring only one, rather than two, preparatory acts. The findings are discussed in terms of the validity of the VIP test in identifying executive functioning impairment and the degree to which the pattern of deficits are consistent with neuropsychological models of executive function. 相似文献
19.
DW Morck JK Merrill BE Thorlakson ME Olson LV Tonkinson JW Costerton 《Canadian Metallurgical Quarterly》1993,202(2):273-277
The prophylactic administration of injectable tilmicosin for pneumonia in weaned beef calves was investigated in 1,806 animals. Comparisons were made among calves receiving an "on-arrival" injection of tilmicosin, calves receiving a single injection of long-acting oxytetracycline, and calves receiving no prophylaxis. Morbidity and mortality attributable to pneumonia, morbidity and mortality attributable to all causes, and case fatality were significantly lower in the group of calves that received tilmicosin, compared with calves that received long-acting oxytetracycline and calves that received no prophylactic antibiotic. Mean time to initial pneumonia treatment was significantly extended in calves that received prophylaxis, compared with those that received no antibiotic on arrival at the feedlot. Calves that received tilmicosin gained significantly more weight than calves that received oxytetracycline. Calves that were not treated for pneumonia during the trial period gained significantly more weight than did those calves that were treated for pneumonia regardless of experimental group. The majority of mortalities were attributable to fibrinous pneumonia (31/34). Important bacterial isolates (Pasteurella spp, Haemophilus somnus, Actinomyces pyogenes) obtained at necropsy did not have resistance to tilmicosin in association with administration of tilmicosin as prophylaxis for pneumonia. However, bacterial resistance to trimethoprim/sulfonamide and to oxytetracycline were commonly found in these postmortem isolates. 相似文献
20.
Fizeau wavemeter for pulsed laser wavelength measurement 总被引:1,自引:0,他引:1