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C 3 H 6 is a typical volatile organic compound (VOC) which is greatly harmful to the environment, however, it is difficult to achieve a complete C 3 H 6 removal at low temperature via the catalytic combustion treatment. In this study, high-performance catalysts of CuO CeO 2 composites were synthesized via a modified flame spray pyrolysis (FSP) method for the catalytic combustion of C 3 H 6. The CuO CeO 2 composites with different Cu molar ratios of 10, 25, 35, 50, and 75% were characterized by N 2 sorption-desorption analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), H 2 temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS). Results show that the composites preserve a nanometer-sized structure with stable micromorphology, which is hardly affected by the molar ratio of Cu. The FSP method is confirmed to be capable of producing solid solution oxides in the composites, which provide abundant reactive oxygen species and good reducibility. XPS, H 2 -TPR results indicate that Cu loading content has a significant impact on the catalytic properties of the prepared CuO CeO 2 catalysts by influencing the content of the solid solution. Compared with other methods, the optimized FSP method can significantly improve the loading of Cu without producing large crystalline CuO particles on the catalyst surface. C 3 H 6 conversion reached a 90% conversion at 380°C indicating an outstanding catalytic performance of the FSP-synthesized CuO CeO 2 catalysts with 35 mol% Cu loading. Moreover, the ignitability of C 3 H 6 is also affected by the catalyst's physicochemical properties, and different active species play the main role in different temperature intervals. [ABSTRACT FROM AUTHOR]

The preparation of bifunctional CaO/CuO composites with high performance is essential for the development of the combined Ca–Cu looping process, in which the exothermic reduction of CuO with methane is used in situ to provide the heat required to calcine CaCO3. However, the rapid decline in CO2 uptake of CaO/CuO composites remains an important problem to be solved, despite their excellent redox characteristic. Herein we report a facile one-pot template-free synthesis approach to yield CaO/CuO hollow microspheres, aimed at enhancing the CO2 capture performance of CaO/CuO composites. CaO/CuO hollow microspheres feature highly porous shells and a homogeneous elemental distribution, and demonstrate significantly enhanced CO2 capture performance. After ten repeated cycles in a fixed-bed reactor, the CO2 uptake capacity of the best-performing CaO/CuO hollow microspheres exceeded that of the reference materials, i.e., CaO/CuO composites synthesized via wet mixing or a co-precipitation method, by 222% and 114%, respectively. Moreover, from cycle number eight onwards, the CO2 uptake was very stable over the tested 20 cycles, suggesting good cyclic stability of CaO/CuO hollow microspheres. Oxidation was always fast with O2 uptake capacities greater than 0.13 gO2 gmaterial−1. On the basis of N2 adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations, the significantly enhanced CO2 capture performance of the CaO/CuO hollow microspheres resulted from the unique hollow microsphere structure with highly porous shells, which were retained throughout the cyclic operations. [ABSTRACT FROM AUTHOR]

Physarum Polycephalum is a unicellular and multi-headed slime mold, which can form high efficient networks connecting spatially separated food sources in the process of foraging. Such adaptive networks exhibit a unique characteristic in which network length and fault tolerance are appropriately balanced. Based on the biological observations, the foraging process of Physarum demonstrates two self-organized behaviors, i.e., search and contraction. In this paper, these two behaviors are captured in a multi-agent system. Two types of agents and three transition rules are designed to imitate the search and the contraction behaviors of Physarum based on the necessary and the sufficient conditions of a self-organized computational system. Some simulations of foraging process are used to investigate the characteristics of our system. Experimental results show that our system can autonomously search for food sources and then converge to a stable solution, which replicates the foraging process of Physarum. Specially, a case study of maze problem is used to estimate the path-finding ability of the foraging behaviors of Physarum. What's more, the model inspired by the foraging behaviors of Physarum is proposed to optimize meta-heuristic algorithms for solving optimization problems. Through comparing the optimized algorithms and the corresponding traditional algorithms, we have found that the optimization strategies have a higher computational performance than their corresponding traditional algorithms, which further justifies that the foraging behaviors of Physarum have a higher computational ability. [ABSTRACT FROM AUTHOR]