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31.
Administered a battery of tests for assessing visual responsiveness to 69 pigtail monkeys 2 days to 6 mo of age. Age changes were found on all tests. None of the responses could be consistently elicited at birth. Tests involving simple sensory capacities and orienting motor responses generally appeared first. Tasks requiring more complicated sensory processing or motor responses emerged at progressively older ages. By 5 wks after birth, normal Ss ordinarily responded positively on all tests. The battery is therefore a convenient and effective screening tool for assessing whether a young monkey has normal vision. Age norms are presented in terms of the percent of Ss at each age expected to respond positively on each test. Results are compared to the development of analogous responses in human infants. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
32.
The spread of microbial contamination on the hides of beef was investigated at two stages in the meat chain: (i) in a simulated livestock market ("the market") using 33 animals, and (ii) in the unloading-to-skinning area of a commercial abattoir using 18 animals. At both stages, harmless bacterial markers (nalidixic acid-resistant Escherichia coli K-12; rifampicin- and nalidixic acid-resistant Pseudomonas fluorescens; and a tetracycline-resistant E. coli) were inoculated on the hides of a small number of selected animals, and their transfer to other animals and the environment was examined. At the market, the initial prevalence of animals positive for the hide markers (9.1% in each phase) introduced in the presale pen, sale ring, and postsale pen changed to 39.4, 15.1, and 54.5%, respectively, by the end of the market process. In addition, widespread contamination of the market environment with the hide markers was observed. At the abattoir, the initial prevalence of animals positive for the hide marker (11.1%) inoculated at unloading increased to 100% (hide before skinning) and 88.8% (skinned carcass). In addition, another marker inoculated on environmental surfaces in lairage pens, races, and stunning box was detected on 83.3% (hide before skinning) and 88.8% (skinned carcass). These results, although obtained with a relatively small number of animals, demonstrate that both the livestock market process and the unloading-to-skinning process at abattoirs can facilitate the extensive spread of microbial contamination on hides not just within, but also between, batches of animals.  相似文献   
33.
The tensile strength of 576 pieces of white line horn collected over 6 mo from 14 dairy cows restricted to parity 1 or 2 was tested. None of the cows had ever been lame. Seven cows were randomly assigned to receive 20 mg/d biotin supplementation, and 7 were not supplemented. Hoof horn samples were taken from zones 2 and 3 (the more proximal and distal sites of the abaxial white line) of the medial and lateral claws of both hind feet on d 1 and on 5 further occasions over 6 mo. The samples were analyzed at 100% water saturation. Hoof slivers were notched to ensure that tensile strength was measured specifically across the white line region. The tensile stress at failure was measured in MPa and was adjusted for the cross-sectional area of the notch site. Data were analyzed in a multilevel model, which accounted for the repeated measures within cows. All other variables were entered as fixed effects. In the final model, there was considerable variation in strength over time. Tensile strength was significantly higher in medial compared with lateral claws, and zone 2 was significantly stronger than zone 3. Where the white line was visibly damaged the tensile strength was low. Biotin supplementation did not affect the tensile strength of the white line. Results of this study indicate that damage to the white line impairs its tensile strength and that in horn with no visible abnormality the white line is weaker in the lateral hind claw than the medial and in zone 3 compared with zone 2. The biomechanical strength was lowest at zone 3 of the lateral hind claw, which is the most common site of white line disease lameness in cattle.  相似文献   
34.
Although it is difficult to describe the nature of clear air turbulence (or CAT), we know its effect?the sudden vibration experienced by an aircraft in flight in a stormfree, cloudfree sky. It is evident that this turbulence is an eddy motion of the air that disrupts its uniform flow, a motion such as that associated with jet streams; however, we do not know exactly how it is generated. Because the effects of CAT can range from mere passenger discomfort to actual loss of an aircraft, it is important to devise some method of warning the pilot of turbulent areas to be avoided. Various indirect and direct detection systems, employing both active and passive techniques, are currently being investigated, but thus far all have exhibited serious limitations on effective performance. One reason for this is the lack of data concerning the phenomenon they are designed to detect.  相似文献   
35.
36.
Differences in motives for condom use and their implications for understanding frequency of use were investigated in a random, biracial (Black, White) sample of heterosexuals, aged 17 to 25 years (n?=?902). Results indicated that sexually active young adults—regardless of race, age, gender, or relationship status—were more likely to use condoms to prevent pregnancy than to prevent disease. Reasons for use mediated the effects of relationship status on condom use per se and moderated the effects of attitudinal and perceptual variables on condom use. Finally, comparisons among condom users motivated by different prevention goals and nonusers (n?=?388) revealed that differences among user subgroups were nearly as numerous and, in some cases, more robust than differences between users and nonusers. These findings indicate that condom users comprise distinct subgroups, defined in part by their underlying motives for use, and highlight important conceptual and empirical reasons to distinguish among them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
37.
Validation of language subtypes in learning disabled children.   总被引:1,自引:0,他引:1  
Hypothesized that children characterized by deficits in narrative skills, relative to other language skills (e.g., syntactic and semantic), would be most at risk for general academic problems, especially in reading comprehension. Using data from a previous longitudinal study by the 1st author and J. D. McKinney (see record 1985-02522-001), different subtypes of language disability were identified in 63 6- and 7-yr-old learning disabled (LD) children. Comparison data had been obtained from 66 non-LD children matched to the LD sample on age, race, and sex. Results, obtained with hierarchical cluster analysis, indicate that 6 language subtypes were derived and that these were both internally consistent and externally valid, being differentially linked to reading and math achievement over a 3-yr period. Narrative ability was shown to be relatively important in predicting academic outcomes. The 3 subtypes showing the poorest academic outcomes had the highest relative scores in syntax and semantics. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
38.
Evidence for unconscious learning has typically been based on dissociations between direct and indirect tests of learning. Because of some inherent problems with dissociation logic, we applied the logic of opposition to 2 artificial grammar learning experiments. In Experiment 1, participants were exposed to 2 different sets of letter strings, generated from 2 different grammars, and later rated test strings for grammaticality with either in-concert (rate grammatical strings consistent with either structure) or opposition (rate grammatical only strings from 1 of the structures) instructions. Manipulating response deadline affected controlled, but not automatic influences. In Experiment 2, after similar training, a source-monitoring test was administered from which the in-concert and opposition conditions were derived. The test indicated that varying the retention interval affected controlled, but not automatic, influences. The results are discussed in terms of awareness, knowledge representation, and metacognitive processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
39.
The present study investigated the role of emotional tone of voice in the perception of spoken words. Listeners were presented with words that had either a happy, sad, or neutral meaning. Each word was spoken in a tone of voice (happy, sad, or neutral) that was congruent, incongruent, or neutral with respect to affective meaning, and naming latencies were collected. Across experiments, tone of voice was either blocked or mixed with respect to emotional meaning. The results suggest that emotional tone of voice facilitated linguistic processing of emotional words in an emotion-congruent fashion. These findings suggest that information about emotional tone is used in the processing of linguistic content influencing the recognition and naming of spoken words in an emotion-congruent manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
40.
One hundred twenty mock jurors heard 1 of several versions of a civil trial. The tort trial was either high or low in information load and contained evidence that either clearly favored the plaintiffs or was ambiguous. Expert witnesses testified in either technical or less technical language. Verdicts favored the plaintiffs when the evidence was clear and was presented in technical language because technical language enhanced witnesses' credibility when the evidence was clear. Although high information loads and technical language hindered evidence processing, jurors endeavored to comprehend, as indicated by the recall of more facts and alternative constructions of the evidence when that evidence was ambiguous. However, those constructions were of poorer quality, incorporating evidence of lesser probative value. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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