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61.
A new multi-chamber cumulative detonation sprayer (MCDS) was applied to fabricate an aluminum oxide coating on carbon/carbon composites. MCDS provides heating and acceleration of ceramic micropowders by means of combustible gas mixture detonation products with a frequency of 20 Hz and above. The ceramic aluminum oxide particle kinetic energy ensures the destruction of the weakened areas on the carbon-carbon composite material surface and the incorporation of these particles into the surface layer. The following powder particles decelerate on the already fixed particles and form a ceramic coating. The formed aluminum oxide coating is characterized by high hardness and low porosity (<1%). MCDS provides the formation of a high-quality ceramic layer, which can also serve as the basis for the formation of protective heat-resistant coatings.  相似文献   
62.
Correlations for the lower limit of the estimate error variance of images distorted by additive and applicative noise are obtained. The potential and actual estimate error variances for linear and nonlinear filtering algorithms are analyzed. A combined filtering algorithm for images distorted by applicative noise is developed.  相似文献   
63.
A recently proposed model to determine particle-size distributions (PSDs) from chord length measurements has been applied to different particle morphologies, namely compact, platelet- and rod-shaped particles. To study these systems, chord length distributions (CLDs) were measured at varying particle size and solids concentration for each compound and were subsequently utilized to determine the system-specific parameters. Each model was successfully applied to its respective compound such that the experimental PSDs and model predictions were in good agreement. Moreover, the effect of other variables such as agitation rate and solvent composition was investigated and found to be negligible for the specific systems tested. Finally, potential model optimizations of the general model construct have been studied. Two variants of the CLD compression step, namely principal component analysis and a geometric model have been considered as surrogate models. However, neither of these approaches yielded superior results than the previously proposed approach.  相似文献   
64.
The in vitro effect of a lipid emulsion (intralipid) on interleukin-2 (IL-2) production by cord blood mononuclear cells (CBMC) of preterm and term newborn infants was examined and compared to that of peripheral blood mononuclear cells (PBMC) of adults. Intralipid, added at concentrations accepted in clinical practice, caused a dose-dependent inhibition of IL-2 activity tested by bioassay. IL-2 levels, tested by radioimmunoassay (RIA), were found to be reduced only in supernatants derived from CBMC of term infants and not in those derived from MC of preterm infants or adults. The capacity of the IL-2 dependent cell line CTLL-2 to respond to IL-2 was abolished in the presence of intralipid, suggesting an interference with the binding of IL-2 to its receptor on these cells. It is conceivable that administration of intralipid to preterm infants may interfere with the binding of IL-2 to the specific receptors on their activated lymphocytes, with a possible subsequent suppression of their immune response.  相似文献   
65.
The effect of mother-infant skin-to-skin contact (kangaroo care, or KC) on self-regulatory processes of premature infants was studied. Seventy-three infants who received KC were compared with 73 infants matched for birth weight, gestational age, medical risk, and family demographics. State organization was measured in 10-s epochs over 4 hr before KC and again at term. No differences between KC infants and controls were found before KC. At term, KC infants showed more mature state distribution and more organized sleep-wake cyclicity. At 3 months, KC infants had higher thresholds to negative emotionality and more efficient arousal modulation while attending to increasingly complex stimuli. At 6 months, longer duration of and shorter latencies to mother-infant shared attention and infant sustained exploration in a toy session were found for KC infants. The results underscore the importance of maternal body contact for infants' physiological, emotional, and cognitive regulatory capacities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
66.
BACKGROUND: Bone cancers in children are serious and highly fatal conditions, yet relatively little is known about their causes or methods of prevention. METHODS: The relationship between parental occupation and bone cancer in offspring was explored in a case-control study. Cases were identified from the Ontario Cancer Registry; population-based controls were matched on sex and age. Data were collected from their parents through the use of a mailed self-administered questionnaire. RESULTS: The odds ratio estimates (OR) for bone cancer were elevated for fathers in the social sciences (OR = 2.5, 95% confidence interval [CI]: 0.7-8.4). Risk of Ewing's sarcoma was significantly high among children with fathers in social sciences (OR = 6.2, 95% CI: 1.6-24.5) and mothers in teaching (OR = 3.1, 95% CI: 1.1-8.7) or farming (OR = 7.8, 95% CI: 1.9-31.7). Osteosarcoma risk was increased for fathers in farming (OR = 2.1, 95% CI: 0.8-5.7), and mothers in managerial and administrative work (OR = 2.3, 95% CI: 0.6-8.1), and product fabricating, assembling, and repairing (OR = 2.0, 95% CI: 0.6-7.2). CONCLUSIONS: Certain methodological problems plague studies of bone cancer in children (e.g. small studies, low statistical power, analysis of multiple occupational categories, difficulty in identifying specific carcinogenic agents). These associations require further investigation, especially as elevated risks have been reported previously for agricultural occupations.  相似文献   
67.
Olanzapine (OLAN), an atypical antipsychotic medication with mixed 5-HT2/DA antagonist properties, was predicted to dose-dependently decrease urge to smoke, withdrawal, and cigarette reinforcement in smokers without psychosis. A double-blind placebo-controlled within-subjects cross-over trial investigated the acute effects of OLAN (0, 2.5, and 5.0 mg; counterbalanced order) in 24 community smokers who underwent 10-hr smoking deprivation. Urge to smoke, tobacco withdrawal, and cigarette reinforcement were assessed with cue reactivity and behavioral choice procedures. OLAN (2.5 mg) reduced withdrawal symptoms before and during cue exposure and decreased urge associated with anticipated positive affect from smoking before and during cue exposure; 5.0 mg OLAN decreased withdrawal only when cues were included. OLAN did not affect preference for cigarette puffs versus money, smoke intake, or urge to smoke associated with negative affect relief. The results indicate a potentially beneficial effect of 2.5 mg OLAN on tobacco withdrawal and urge to smoke. Combined 5HT/DA antagonists should be considered for future development of pharmacotherapies for smoking cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
68.
Social learning theories suggest that conditioned responses may increase the risk for relapse. Responses to alcohol use cues (cue reactivity) are associated with variables suggestive of risk but little research exists on the relationship of cue reactivity to treatment outcome. Alcoholic men admitted for detoxification to a treatment program (n?=?45) underwent a cue reactivity assessment protocol, and 91% received 3-mo follow-up interviews. Greater salivary reactivity predicted greater frequency of drinking during follow-up. Attentional factors added independent variance to the prediction of drinking outcome, with greater attention to stimulus or to response predicting less drinking. Cue reactivity did not predict length of hospital stay or latency to first drink. Results are discussed in the context of information processing, social learning theories, and clinical implications for relapse prevention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
69.
The effect of daily dietary supplements of an antioxidant mixture (AM) consisting of beta carotene, alpha tocopherol, ascorbic acid, rutin, selenium, and zinc on the survival of male C57BL/6 mice starting at 2, 9, 16, and 23 months of age was investigated. The survival of mice given AM starting at 2 and 9 months of age was found to increase significantly (from 86 to 108 days) compared to the control. The times, of 50, 90, and 100% mortality in mice given AM starting at 2 and 9 months of age increased by 16-9.5% compared to the control, whereas in mice given AM, starting at 16 and 23 months of age, no effect was observed.  相似文献   
70.
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