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91.
Reconstituted infant formula has been implicated in outbreaks of Enterobacter sakazakii infections, causing high mortality and serious sequelae. Current prevention methods appear to be insufficient to ensure that such foods are free of E. sakazakii. In this study, the usefulness of bacteriophages for biocontrol of E. sakazakii was investigated. Of a total of six new E. sakazakii phages isolated from sewage and UV irradiated cultures, two were selected for further study by electron microscopy, DNA restriction analysis and SDS-PAGE of structural proteins. Purified phages were used to control bacterial growth in broth medium and reconstituted infant formula. Both phages effectively prevented development of E. sakazakii in formula at various temperatures (12, 24 and 37 degrees C), the efficiency of which was dependent upon intrinsic lysis properties and the applied phage concentration. We conclude that application of specific bacteriophages may provide a means for efficient prevention of E. sakazakii infection through reconstituted infant formula.  相似文献   
92.
Flavours are biologically active molecules of large commercial interest in the food, cosmetics, detergent and pharmaceutical industries. The production of flavours can take place by either extraction from plant materials, chemical synthesis, biological conversion of precursor molecules or de novo biosynthesis. The latter alternatives are gaining importance through the rapidly growing fields of systems biology and metabolic engineering, giving efficient production hosts for the so‐called 'bioflavours', which are natural flavour and/or fragrance compounds obtained with cell factories or enzymatic systems. Yeasts are potential production hosts for bioflavours. In this mini‐review, we give an overview of bioflavour production in yeasts from the process‐engineering perspective. Two specific examples, production of 2‐phenylethanol and vanillin, are used to illustrate the process challenges and strategies used. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
93.
Cystoisospora belli is an opportunistic protozoan that causes human cystoisosporiasis, an infection characterized by diarrhea, steatorrhea, abdominal pain, fever, and weight loss. The lack of animal models susceptible to C. belli, and the difficulty in obtaining clinical samples with fair amounts of oocysts have limited the research pertaining to the basic biology of this parasite. This study aimed to describe the ultrastructure of endogenous stages of C. belli in Monkey Rhesus Kidney Cells (MK2) and Human Ileocecal Adenocarcinoma cells (HCT‐8). Zoites of C. belli exhibited typical morphological features of coccidia, which included a trilaminar pellicle, an apical complex formed by a conoid, polar rings, rhoptries, and micronemes, in addition to dense granules and the endoplasmic reticulum. No crystalloid body was observed but various lipid and amylopectin granules were usually present in the cytoplasm of zoites. We observed a tendency of the endoplasmic reticulum of the host cell to be located near the parasitophorous vacuole membrane. Merozoites were formed by endodyogeny and during replication, the apical complex of the mother cell remained intact. The formation of gametes or oocysts was not observed. The ultrastructural findings of C. belli are further evidence of its proximity to Sarcocystidae family members and corroborate their reclassification as Cystoisospora spp. Microsc. Res. Tech. 77:472–478, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
94.
Macrophages synthesize active vitamin D (1,25-dihydroxy-vitamin D) and express the vitamin D receptor in the nucleus; however, vitamin D metabolism in relation to macrophage polarization and function is not well understood. We studied monocyte-derived macrophages (MDMs) from human buffy coats polarized into M0, M1 (LPS + IFNγ), M2a (IL4 + IL13) and M2c (IL10) macrophage subtypes stimulated with 25-hydroxy-vitamin D (1000 and 10,000 nanomolar). We measured vitamin D metabolites (25-hydroxy-vitamin D, 1,25-dihydroxy-vitamin D, 24,25-dihydroxy-vitamin D and 3-epi-25-hydroxy-vitamin D) in cell media with liquid chromatography-mass spectrometry-mass spectrometry. The mRNA expression (CYP27B1, CYP24A1 and CYP24A1-SV) was measured with qPCR. We found that reparative MDMs (M2a) had significantly more 1,25-dihydroxy-vitamin D compared to the other MDMs (M0, M1 and M2c). All MDMs were able to produce 3-epi-25-hydroxy-vitamin D, but this pathway was almost completely attenuated in inflammatory M1 MDMs. All MDM subtypes degraded vitamin D through the 24-hydroxylase pathway, although M1 MDMs mainly expressed an inactive splice variant of CYP24A1, coding the degrading enzyme. In conclusion, this study shows that vitamin D metabolism is highly dependent on macrophage polarization and that the C3-epimerase pathway for vitamin D is active in macrophages.  相似文献   
95.
Semantic priming is traditionally viewed as an effect that rapidly decays. A new view of long-term word priming in attractor neural networks is proposed. The model predicts long-term semantic priming under certain conditions. That is, the task must engage semantic-level processing to a sufficient degree. The predictions were confirmed in computer simulations and in 3 experiments. Experiment 1 showed that when target words are each preceded by multiple semantically related primes, there is long-lag priming on a semantic decision task but not on a lexical-decision task. Experiment 2 replicated the long-term semantic priming effect for semantic decisions with only one prime per target. Experiment 3 demonstrated semantic priming with much longer word lists at lags of 0, 4, and 8 items. These are the first experiments to demonstrate a semantic priming effect spanning many intervening items and lasting much longer than a few seconds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
96.
36 male alcoholics (13 with Korsakoff's syndrome) and 24 controls performed visual and auditory delayed-response tasks sensitive to prefrontal cortical damage in nonhuman primates. Korsakoff patients were consistently impaired compared with other Ss. Impairments by Korsakoff patients were evident when demands were placed on visual processing time (brief stimulus durations), and the deficits became exaggerated with increased demands on short-term memory. Under the most difficult experimental conditions, controls and non-Korsakoff alcoholics who were over 50 yrs old performed somewhat worse compared with younger groups 27–49 yrs old. Age-linked deficits were mild compared with Korsakoff's deficits, and age-group differences disappeared with easier task demands. The results implicate cortical pathology in alcoholism and normal chronological aging and suggest that prefrontal damage accompanies Korsakoff's syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
97.
Eighteen chronic schizophrenia patients and 14 controls were given tests that have been linked primarily to ventral (orbitofrontal) or to dorsolateral prefrontal dysfunctions in neurological patients and in nonhuman animal Ss having discrete frontal lesions. Schizophrenia patients were significantly impaired on object alternation and delayed alternation tasks but not on classical delayed response (DR). Schizophrenia patients performed well on the classical version of the DR task and their DR performance correlated significantly with measures of sustained attention. Future research is needed to interpret the contributions of attention, interference, and memory load to neuropsychological performance in schizophrenia. Additional studies are required to determine whether the frontal deficits reflect diffuse brain damage, circumscribed prefrontal damage, or damage in other brain regions having prefrontal connections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
98.
Although it is now well accepted that visual mental imagery and visual perception share common underlying mechanisms, there are several reports in which they are dissociated. Evidence for the separability of these processes is provided by a 33-yr-old male patient who has a profound visual object recognition deficit attributable to an impairment in grouping or segmenting visual images. Despite this perceptual deficit, the patient was able to draw objects in considerable detail from memory, and his knowledge of the visual appearance of objects was preserved on a variety of mental imagery tasks. Together with previous cases, these findings confirm the double dissociation between object recognition and perception. Interestingly, the patient could also recognize newly constructed objects in his internal imagery. To accommodate these results, the authors propose a model in which imagery and perception are strongly associated but are also functionally specialized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
99.
In 2 experiments with a total of 24 undergraduates, eye movements were monitored while Ss performed parallel and serial search tasks. In Exp 1a, Ss searched for an "O" among "X"s (parallel condition) and for a "T" among "L"s (serial condition). In the parallel condition of Exp 1b, "Q" was the target and "O"s were distractors; in the serial condition, these stimuli switched roles. Displays contained 1, 12, or 24 stimuli, with both target-present and target-absent trials. RT and eye-movement measures (number of fixations, saccadic error, and latency to move) indicated that search efficiency was greatest in the parallel conditions, followed by the serial condition of Exp 1a and, finally, by the serial condition of Exp 1b. This suggests that eye movements are correlated with the attentional processes underlying visual search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
100.
Investigated the effects of a group therapy program utilizing social learning theory, experiential methods, and a sociocultural perspective with 14 18–45 yr old bulimarexic women. Bulimarexia was operationally defined as a cyclical eating disorder characterized by bingeing–purging behaviors and abnormally low self-esteem. Ss had been binge-eating and purging via forced vomiting, laxative abuse, or habitual fasting and dieting on a daily basis for at least 4 yrs. None of the Ss were significantly underweight, overweight, or in need of medical management at the time of treatment. Dependent measures included responses to the California Psychological Inventory (CPI) and a modified Body Cathexis Scale (BCS), which were administered pre, post, and 1 yr following the group treatment procedure. Application of repeated measures ANOVA to the CPI yielded significant results on 8 of 18 scales. The BCS data proved significant at posttest and at 1 yr follow-up. Bingeing behaviors were eliminated or attenuated in 10 of 14 cases. Results are consistent with the idea that bulimarexia is related to the struggle to achieve a perfect, stereotypic female image in which women surrender most of their self-defining powers to others. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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