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631.
The choice of suitable normal foods is limited for individuals with particular medical conditions, e.g., inborn errors of metabolism (phenylketonuria – PKU) or severe cow’s milk protein allergy (CMPA). Patients may have dietary restrictions and exclusive or partial replacement of specific food groups with specially formulated products to meet particular nutrition requirements. Artificial sweeteners are used to improve the appearance and palatability of such food products to avoid food refusal and ensure dietary adherence. Young children have a higher risk of exceeding acceptable daily intakes for additives than adults due to higher food intakes kg–1 body weight. The Budget Method and EFSA’s Food Additives Intake Model (FAIM) are not equipped to assess partial dietary replacement with special formulations as they are built on data from dietary surveys of consumers without special medical requirements impacting the diet. The aim of this study was to explore dietary exposure modelling as a means of estimating the intake of artificial sweeteners by young PKU and CMPA patients aged 1–3 years. An adapted validated probabilistic model (FACET) was used to assess patients’ exposure to artificial sweeteners. Food consumption data were derived from the food consumption survey data of healthy young children in Ireland from the National Preschool and Nutrition Survey (NPNS, 2010–11). Specially formulated foods for special medical purposes were included in the exposure model to replace restricted foods. Inclusion was based on recommendations for adequate protein intake and dietary adherence data. Exposure assessment results indicated that young children with PKU and CMPA have higher relative average intakes of artificial sweeteners than healthy young children. The reliability and robustness of the model in the estimation of patient additive exposures was further investigated and provides the first exposure estimates for these special populations.  相似文献   
632.
Since the early 2000s, labeling of potentially allergenic food components to protect people who suffer from food allergies is compulsory in numerous industrialized countries. In Europe, milk and egg components used during the winemaking process must be indicated on the label since July 1, 2012. Several ELISA procedures have been developed to detect allergenic residues in wines. However, the complexity of the wine matrix can inhibit the immunoenzymatic reaction. The aim of this study was to implement an ELISA assay for the detection of ovalbumin in red wines using commercially available antibodies. The specificity of the acquired antibodies and the absence of cross reactivity were assessed by immunoblotting and ELISA. An ELISA assay with a LOD of 14.2 μg/L and a LOQ of 56.4 μg/L of ovalbumin in aqueous solution was obtained. Differences in ELISA signals were observed when analyzing various fining agents, although reproducible conformation of the antigen could be reached for the comparison of ovalbumin and Ovicolle. The differences between samples in terms of pH could be leveled but the inhibition of the ELISA signal, positively correlated to the tannin content of the wines, could not be suppressed. Thus, standard curves of ovalbumin in several wines were obtained by relative quantification. The control steps and the difficulties encountered presented in this study should be considered by anybody working toward the development of ELISA assays for the detection of allergenic residues in complex food matrices.  相似文献   
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634.
In recent years, the development of new bio-based products for biocontrol has been gaining importance as it contributes to reducing the use of synthetic herbicides in agriculture. Conventional herbicides (i.e., the ones with synthetic molecules) can lead to adverse effects such as human diseases (cancers, neurodegenerative diseases, reproductive perturbations, etc.) but also to disturbing the environment because of their drift in the air, transport throughout aquatic systems and persistence across different environments. The use of natural molecules seems to be a very good alternative for maintaining productive agriculture but without the negative side effects of synthetic herbicides. In this context, essential oils and their components are increasingly studied in order to produce several categories of biopesticides thanks to their well-known biocidal activities. However, these molecules can also be potentially hazardous to humans and the environment. This article reviews the state of the literature and regulations with regard to the potential risks related to the use of essential oils as bioherbicides in agricultural and horticultural applications.  相似文献   
635.
The fatigue life of metallic aircraft structural components can be significantly reduced by environmentally induced corrosion. As part of a NAVAIR High Strength Steel Corrosion–Fatigue Assessment Program, methods were studied to predict the impact that corrosion-induced surface roughness has on the fatigue life of high-strength steel aircraft components. In order to adequately capture the corrosion damage features that cause fatigue cracking, a representative set of well-characterized corrosion–fatigue test results were generated to be used for model development. The test specimens fabricated for this program consisted of bare, unnotched AF1410 steel flat plates with a 25.4 mm diameter corrosion patch on one side. Two sets of test specimens were fabricated and tested, with one set abrasive blasted after heat treatment, and the other set hand polished after heat treatment. A method of growing corrosion in the laboratory was developed that consisted of filter paper soaked in a 3.5% NaCl solution and placed at the center of the test plate gage section, with a voltage applied across the filter paper to accelerate corrosion growth. High-resolution 3D surface topography data was collected from the corroded region on each test plate prior to fatigue testing using a commercial white-light interference microscope. Constant-amplitude fatigue tests were performed on corroded and uncorroded test plates at several different stress levels, for three different corrosion exposure levels. Post-test fractographic analysis of the corroded specimens indicate that all of the critical cracks originated from small corrosion notches on the order of 10–200 μm in width, 10–120 μm in height and 2–100 μm in depth. These notches were not considered to be pits in that the depth dimension was less than the surface dimensions. The repeatability of the fatigue initiating mechanism for corrosion damaged surfaces in this material indicates that it should be possible to develop a single modeling approach that reasonably captures the effects of corrosion notches in reducing fatigue life.  相似文献   
636.
Carbon aerogels exhibiting high porous volumes and high surface areas, differentiated by their pore-size distributions were used as Pt-supports in the cathode catalytic layer of H2/air-fed PEM fuel cell. The cathodes were tested as 50 cm2 membrane electrode assemblies (MEAs). The porous structure of the synthesized catalytic layers was impacted by the nanostructure of the Pt-doped carbon aerogels (Pt/CAs). In this paper thus we present an experimental study aiming at establishing links between the porous structure of the cathode catalytic layers and the MEAs performances. For that purpose, the polarization curves of the MEAs were decomposed in 3 contributions: the kinetic loss, the ohmic loss and the mass-transport loss. We showed that the MEAs made with the different carbon aerogels had similar kinetic activities (low current density performance) but very different mass-transport voltage losses. It was found that the higher the pore-size of the initial carbon aerogel, the higher the mass-transport voltage losses. Supported by our porosimetry (N2-adsorption and Hg-porosimetry) measurement, we interpret this apparent contradiction as the consequence of the more important Nafion penetration into the carbon aeorogel with larger pore-size. Indeed, the catalytic layers made from the larger pore-size carbon aerogel had lower porosities. We thus show in this work that carbon aerogels are materials with tailored nanostructured structure which can be used as model materials for experimentally testing the optimization of the PEM fuel cell catalytic layers.  相似文献   
637.
Scrapie is the most common transmissible spongiform encephalopathy (TSE) in livestock. Natural contamination in sheep flocks is presumed to occur by maternal transmission to offspring. However, horizontal prion transmission from animal to animal exists and may be significant in sustaining and spreading contagion in the field. Artificial insemination is widely used in modern farming, and as large amounts of prion protein have been found in sheep sperm membrane, epididymal fluid and seminal plasma, horizontal transmission by this route was hypothesized since no clear information has been obtained on possible sexual transmission of TSE. We therefore tested the contamination levels of semen from scrapie-infected rams at different stages of incubation, including the clinical phase of the disease. We report here that under our experimental conditions ram semen did not transmit infectivity to scrapie-susceptible transgenic mice overexpressing the V(136)R(154)Q(171) allele of the sheep prion (PRNP) gene. These results suggest that artificial insemination and natural mating have a very low or negligible potential for the transmission of scrapie in sheep flocks.  相似文献   
638.
PURPOSE: To examine the costs and benefits of routine follow-up evaluation in patients treated with radiation therapy for early-stage Hodgkin's disease. PATIENTS AND METHODS: We retrospectively examined patterns of follow-up evaluation and methods of relapse detection among 709 patients with stage I and II Hodgkin's disease treated with primary radiotherapy between 1969 and 1994. We determined the probability of relapse detection for seven routine follow-up procedures, compared their relative costs, and determined the impact of each procedure on the likelihood of survival following salvage therapy. RESULTS: Relapse has occurred in 157 patients (22%) at a median 1.9 years (range, 0 to 13 years) posttreatment. Relapse was suspected primarily by history (Hx) in 55% of patients, physical examination (PE) in 14%, chest x-ray (CXR) in 23%, and abdominal x-ray (KUB) in 7%. Only one relapse (1%) was identified by a routine laboratory study. The rate of relapse detection was highest for a combination of Hx and PE (78 of 10,000 examinations) followed by CXR (26 of 10,000 examinations). The projected charges (1995 dollars) per relapse detected by routine follow-up Hx and PE were $11,000 compared with $68,000 for CXR and $142,000 for KUB. The 10-year actuarial survival rate following salvage therapy was 65% overall, 65% for patients in whom relapse was detected by Hx or PE, and 69% for patients in whom relapse was detected by radiographs (P = not significant). CONCLUSION: The majority of relapses occurred within 5 years of treatment and were identified by Hx and PE. CXR was useful during the first 3 years of follow-up evaluation. KUB, CBC, and laboratory studies accounted for nearly half of all follow-up charges and rarely led to the detection of relapse. Their routine use as a method of relapse detection is questionable. In general, the method of relapse detection did not have a significant impact on the likelihood of successful salvage therapy.  相似文献   
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