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排序方式: 共有715条查询结果,搜索用时 15 毫秒
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A. Bassam I. Salgado‐Tránsito I. Oller E. Santoyo A.E. Jiménez J.A. Hernandez A. Zapata S. Malato 《国际能源研究杂志》2012,36(14):1314-1324
Artificial neural networks (ANN) were proposed as a multivariate experimental design tool for monitoring a photo‐Fenton treatment of wastewaters containing a synthetic mixture of pesticides. ANN and Nelder‐Mead simplex methods were used to find out the optimum operating parameters of a photo‐Fenton pilot plant. ANN was developed to predict the most important operating parameters (e.g., the total organic carbon and the initial mineralization kinetic rate constants of the reactions), which determine the photo‐catalytic degradation efficiency in photo‐Fenton processes. Experimental measurements of temperature, pH, hydrogen peroxide (H2O2) consumption, initial concentration of Fe2+, and the AE were used as input data for the ANN learning. A feed‐forward with one hidden layer, a Levenberg–Marquardt learning algorithm, a hyperbolic tangent sigmoidal transfer function and a linear transfer function were used to develop the ANN model. The best fitting of the training database was obtained with an ANN architecture constituted by seven neurons in the hidden layer. The simulated results were validated with experimental measurements, showing an acceptable agreement (R2 > 0.99). The ANN was subsequently coupled with a Nelder–Mead simplex method to obtain the optimum operating parameters of the photo‐Fenton pilot plant. The H2O2 consumption was used as key variable for evaluating the optimization procedure. Errors less than 1% between simulated and experimental data were found. The obtained results showed that the use of ANN provides an excellent predictive performance tool with the additional capability to assess the influence of each operating parameter on the removal process of water pollutants. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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In this paper, we consider the existence of almost periodic solutions for impulsive fractional evolution equations involving Caputo fractional derivative. The main results are obtained by means of the theory of operators semi-group, probability density functions, fixed point theorems and the techniques based on fractional calculus. An example is also discussed to illustrate the theory. Some known results are improved and generalized. 相似文献
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Alicja Bakalarz 《Mineral Processing and Extractive Metallurgy Review》2019,40(6):437-446
ABSTRACTThe study involved the chemical and mineralogical analysis of actual tailings production from Lubin Concentrator Plant (KGHM Polska Miedz SA Group). KGHM Polska Miedz SA Group is the world’s leading company that mines and processes sediment-hosted stratiform copper deposits in SW Poland. From the beginning of copper ore mining, the problem of utilization and managing the deposited tailings has been discussed. Annually, all three concentrators produce above 30 million tons of flotation tailings. Lubin Concentrator Plant processes the most complex in upgradeability ore from the other two concentrators. The total loss of copper-bearing minerals in 0.020–0.071 mm size fraction was found to be 52%. The analysis of liberation showed that in fines (–0.020 mm) over 50% of sulfides is released while the amount of totally locked sulfides in the sample constitutes for 65%. The main cause of significant decline in the finest fractions should be attributed to inappropriate flotation time or too low collector dose. Insufficient liberation of sulfides in the coarser fractions can be a reason for the loss of copper in these fractions. The presented results of final tailings confirm the main cause of metal losses in tailings to be very complex mineral properties. 相似文献
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ABSTRACT Concern over increasing water scarcity has led to the introduction of the concept of agricultural water productivity and an emphasis on interventions to achieve ‘more crop per drop’. Yet, a strong debate continues on how the concept is to be defined and used. Drawing largely from the irrigation literature, the origins of the concept and its methodological developments are reviewed, and its use in applied work over two decades is discussed. Based on this analysis of conceptual and applied research, key insights into the concept’s contributions and limitations are presented, as well as opportunities for further refinements. 相似文献
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Dr. Barbara Tränkenschuh 《真空研究与实践》2013,25(1):6-12
Cleaning before coating — the last step of the manufacturing process Before coating the surface of the component which shall be coated is cleaned. Several machines and chemicals can be used. After the cleaning the surface must be ready for coating. The influence of the machining parameters on the surface of a component is shown. The effectiveness of the cleaning processes prior to coating is discussed, and put in context to the whole manufacturing process. A classification of the manufacturing process should not be based on the different locations where it takes place. All the machining steps which influence the properties and the coat ability of the metal surface should be considered as connected. All these treatment steps are ideally tuned in a way that the surface can be coated flawlessly. 相似文献
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Nowadays the most machining tools are coated with hard coatings to prolong their lifetime and to improve their working efficiency. They are very often used for high wear applications, where they are subjected to cyclic impact loading. Main benefits of hard coatings are based on the combination of high hardness and toughness, properties that are especially important in the conditions of dynamic impact wear when high cyclic local loading is the main cause of coating degradation. A cavitation test can be a useful tool for studies of plastic deformation, crack initiation and propagation in thin hard coatings. Cavitation damage is caused by repeating action of imploding cavitation bubbles in the vicinity of solid surface. 相似文献
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Adam I. Cygankiewicz Alicja Maslowska Wanda M. Krajewska 《Critical reviews in food science and nutrition》2014,54(6):771-780
Taste perception is one of the senses crucial for many organisms. There are five basic tastes, i.e., sweet, bitter, salty, sour, and umami, and it is suggested that the taste of fat should be included in this list. This paper reviews the current state of knowledge about the involvement of G protein coupled receptors (GPCRs) in taste sensing and intracellular signaling. GPCR receptors are focal point of interest for pharmaceutical industry. However, their ability to interact with a variety of taste substances makes these receptors interesting target for food and nutrient companies. 相似文献