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1.
Gold and palladium were supported on a mesoporous TiO2 for total oxidation of volatile organic compounds (VOCs). Mesoporous high surface area titania support was synthesised using of Ti(OC2H5)2 in the presence of CTMABr surfactant. After removing the surfactant molecules, 0.5 or 1.5 wt% of palladium and 1 wt% of gold were precipitated on the support by, respectively, wet impregnation and deposition–precipitation methods. The activity for toluene and propene total oxidation of the prereduced samples follows the same order: 0.5%Pd-1%Au/TiO2 > 1.5%Pd/TiO2 > 0.5%Pd/TiO2 > 1%Au-0.5%Pd/TiO2 > 1%Au/TiO2 > TiO2. Moreover, a catalytic comparison with samples based on a conventional TiO2, shows the catalytic advantage of the mesoporous TiO2 support. The promotional effect of gold added to palladium could be partly explained by small metallic particles (TEM), but meanly by metallic particles made up of Au-rich core with a Pd-rich shell. Moreover, the hydrogen TPR profile of 0.5%Pd-1%Au/TiO2 shows only the signal attributed to small PdO particles. Gold also implies a protecting effect of the support under reduction atmosphere. Operando diffuse reflectance infrared fourier transform (DRIFT) spectroscopy was carried on and allowed to follow the VOCs oxidation and the formation of coke molecules, but also a metallic electrodonor effect to the adsorbed molecule which increases in the same order as the activity for oxidation reaction. The presence of coke after test was also shown by DTA–TGA by exothermic signals between 300 and 500 °C and by EPR (g = 2.003).  相似文献   
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3.
Performance data are presented for methane oxidation on alumina-supported Pd, Pt, and Rh catalysts under both fuel-rich and fuel-lean conditions. Catalyst activity was measured in a micro-scale isothermal reactor at temperatures between 300 and 800 °C. Non-isothermal (near adiabatic) temperature and reaction data were obtained in a full-length (non-differential) sub-scale reactor operating at high pressure (0.9 MPa) and constant inlet temperature, simulating actual reactor operation in catalytic combustion applications.

Under fuel-lean conditions, Pd catalyst was the most active, although deactivation occurred above 650 °C, with reactivation upon cooling. Rh catalyst also deactivated above 750 °C, but did not reactivate. Pt catalyst was active above 600 °C. Fuel-lean reaction products were CO2 and H2O for all three catalysts.

The same catalysts tested under fuel-rich conditions demonstrated much higher activity. In addition, a ‘lightoff’ temperature was found (between 450 and 600 °C), where a stepwise increase in reaction rate was observed. Following ‘lightoff’ partial oxidation products (CO, H2) appeared in the mixture, and their concentration increased with increasing temperature. All three catalysts exhibited this behavior.

High-pressure (0.9 MPa) sub-scale reactor and combustor data are shown, demonstrating the benefits of fuel-rich operation over the catalyst for ultra-low emissions combustion.  相似文献   

4.
The selection of the optimal band combination for the estimation of specific crop variables is a key aspect in order to obtain reliable estimation of in-field variability from multi- and hyperspectral remote-sensing data. The selection of the bands is strongly influenced by the phenological stage of the crop at the acquisition time. In this work, the influence of the growing stage on the combination of spectral bands related to grain nitrogen (N) uptake in wheat was evaluated using multispectral (Satellite Pour l’Observation de la Terre – SPOT) and hyperspectral (Compact High Resolution Imaging Spectrometer – CHRIS-PROBA) satellite images at different growth stages over two wheat growth seasons in central Italy. In order to identify the more appropriate covariates (spectral bands) for each phenological stage, stepwise regression with backward selection was combined with stepwise variance inflation factors (VIFs) analysis and linear mixed effect model (LMEM). The results obtained in this study suggest that the spectral region most related to N uptake varies over the growing season of the wheat crop. For SPOT data, near-infrared (NIR) region was selected at all the phenological stages in both growing seasons, except for the latest stage, with low chlorophyll content due to the onset of senescence, in which the red band was selected. At stem elongation, the shortwave infrared (SWIR) band of SPOT data was also selected. At this stage, the best N estimation accuracy was obtained using an LMEM (root mean square error, RMSE = 0.012 t ha?1). The inclusion of a spatial component in the estimation model by means of LMEMs provided a more accurate estimation than ordinary least square (OLS) models at all growth stages. The test carried out with CHRIS-PROBA data at the fourth stage confirmed the importance of NIR and in particular of the red-edge region for N uptake prediction. A novel methodology is proposed, which involves two crucial aspects in the context of the use of remote-sensing data in precision agriculture: i) the standardization of the spatial resolution for in-field and satellite data by a geostatistical data technique (data fusion); and ii) the selection of the most appropriate spectral bands for each phenological stage, taking into account both correlation with the target variable and collinearity.  相似文献   
5.
This paper extends the emerging literature on the value of trademarks for innovation studies and policy-making with the first empirical study at the trademark level. It gives a view on how companies use trademarks and interpret trademark activities. A sample of 660 new Benelux trademarks registered by small- and medium-sized enterprises reveals that 60 per cent of recently registered Benelux trademarks refer to innovation activity, predominantly to product or service innovation. The reference to innovation co-varies with various applicant and trademark characteristics unknown from previous studies. Finally, the sample reveals that most of the trademarks used to signal innovative offers are filed close to its market introduction without combining them with other intellectual property rights. This holds especially for trademarks related to service innovation.  相似文献   
6.
Wind turbines are complex dynamic systems forced by stochastic wind disturbances, as well as gravitational, centrifugal, and gyroscopic loads. Since their aerodynamics are nonlinear, wind turbine modelling is thus challenging. Moreover, accurate models should contain many degrees of freedom to capture the most important dynamic effects. Therefore, the design of control algorithms for wind turbines should account for these complexities. However, these algorithms must capture the most important turbine dynamics without being too complex and unwieldy. The main purpose of this study is thus to give two examples of viable and practical designs of control schemes with application to a wind turbine prototype model. Extensive simulations on the benchmark process and Monte-Carlo analysis are the tools for assessing experimentally the main features of the proposed control schemes, in the presence of modelling and measurement errors. These developed control methods are also compared with other different approaches, in order to evaluate advantages and drawbacks of the considered solutions. Finally, Hardware-In-the-Loop simulations serve to highlight the potential application of the proposed control strategies to real wind turbines.  相似文献   
7.
With the object to disclose an association between laryngeal papillomatosis and laryngeal carcinoma, we reviewed 102 patients with laryngeal papillomatosis treated between 1950 and 1979. Seven cases of laryngeal carcinomas were recorded and 1 patient with spread of papilloma to the bronchial tree developed a bronchial carcinoma. The time between onset of papilloma and diagnosis of carcinoma was 4-55 years (mean 24 years). For laryngeal carcinoma the ratio of observed to expected cases was 88. Of the 8 patients developing respiratory tract carcinoma, 2 had received treatment with radiation and 2 had been treated with Bleomycin. Four of these 8 patients were known smokers. This study shows that papillomatosis is more often associated with laryngeal carcinoma than previously reported. It appears, however, that laryngeal papillomas alone seldom induce carcinomas. Apart from irradiation and smoking, Bleomycin could be an important co-factor.  相似文献   
8.
We describe the apparatus used in experiment UA4 to study proton-antiproton elastic and inelastic interactions at the CERN SPS Collider. Elastically scattered particles, travelling at very small angles, are observed by detectors placed inside movable sections (“Roman pots”) of the SPS vacuum chamber. The deflection in the field of the machine quadrupoles allow the measurement of the particle momentum. Inelastic interactions are observed by a left-right symmetric system of trigger counter hodoscopes and drift-chamber telescopes. The apparatus reconstructs the interaction vertex and measures the pseudorapidity η of charged particles in the range 2.5 < 6η6 < 5.6.  相似文献   
9.
Monoarthritis     
By definition, monoarticular arthritis means one-joint involvement, even though, in fact, such a condition is often an oligoarthritis because as many as two or three separate joints will be involved. Arthritis is often limited and may regress, so that it is frequently misdiagnosed. Sometimes, a monoarticular condition may be a polyarthritis onset (i.e., rheumatoid arthritis). Monoarticular arthritis can be caused by many factors, such as infections (septic arthritis), nonspecific inflammatory processes (reactive arthritis), crystals deposition (gout, CPPD crystal deposition disease), trauma, neoplasm (pigmented villonodular synovitis), immunologic conditions (amyloidosis) and hormonal changes (parathyroid disease). Its onset is usually acute and sometimes dramatic, with fever, pain and joint swelling, so that a decision must be made promptly to stop rapid illness evolution and to prevent the irreversible destruction of cartilage and bone (especially in septic arthritis). Diagnostic studies are performed with mono-bilateral radiographs of the joint. Radiographic findings (i.e., soft tissue swelling, joint effusion, widening and thinning of joint spaces, bone erosions and destruction of bone surface) are typical of the disease, but some findings (e.g., type of evolution and progression), laboratory tests, synovial biopsy and arthroscopy can differentiate infectious from inflammatory forms. Scintigraphy can depict isotopic joint uptake, before articular abnormalities are demonstrated with radiography, thanks to its high sensitivity; nevertheless, because of its low specificity, scintigraphy may miss some kinds of lesions (including osteoarthritis) and cannot easily differentiate osteomyelitis from septic arthritis. CT and MRI play a secondary, though not negligible, role, especially to study such deep infections as psoas abscesses, which may mimic arthritides.  相似文献   
10.
Energy demands will increase as industrialized nations strive to maintain progress and productivity gains and as developing nations increase their consumption and productivity. One direction that is evolving to satisfy the demand while minimizing environmental impacts is to move toward a hydrogen economy. For the foreseeable future, the majority of these demands will be met through the increased usage of fossil fuels. One of the most abundant and readily available fuels is coal. This realization has raised some questions about the responsible use of such a fuel and as such it is critical that a Greenhouse Gas Management strategy/technology be developed to forestall projected global warming and its impacts.  相似文献   
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