Smith-Purcell radiation (SPR) is a versatile platform for finely tuning nanoscale light across a broad spectral range. This study introduces a theoretical approach for shaping SPR wavefronts using aperiodic metagratin...
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Smith-Purcell radiation (SPR) is a versatile platform for finely tuning nanoscale light across a broad spectral range. This study introduces a theoretical approach for shaping SPR wavefronts using aperiodic metagratings (AMGs). The AMGs consist of arrays of identical metal nano-rods (MNRs), with each MNR's spatial position precisely adjustable. This precise adjustment allows for effective modulation of the spatial phase distribution of SPR. To demonstrate the efficacy of this method, we conduct simulations to achieve diverse wavefront profiles of focusing, deflection, Bessel beams, and Airy beams. Additionally, our approach allows for integrating multiple SPR wavefront functionalities within a combo AMG. By employing the asymmetric L-shaped meta-atom design, we achieve simultaneous SPR polarization conversion and wavefront shaping. This method is promising for developing highly adaptable and multifunctional nanoscale light sources. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
This study proposes an edge-preserving image interpolation algorithm for both clean images and polluted images. First, the structure of an image window is learnt adaptively by using a spatial general autoregressive (S...
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This study proposes an edge-preserving image interpolation algorithm for both clean images and polluted images. First, the structure of an image window is learnt adaptively by using a spatial general autoregressive (SGAR) model that is a uniform expression for both linear and non-linear autoregressive (AR) models. Parameters of the SGAR model are estimated in a moving window in the input low-resolution image by using the robust generalised M-estimator. Next, the interpolation model is established from the learnt model and a new feedback mechanism in accordance with the residual sum of squares minimisation principle. Finally, the gradient simulated annealing algorithm is used to solve the interpolation model, which can rapidly converge to the global optimum in probability with the help of gradient information. Experiments have been performed using worldwide datasets to evaluate the performance of the authors method. The results demonstrate that their method is superior to a recent AR model-based method and is bicubic, especially when images are polluted by noise such as Gaussian noise, Poisson noise, impulse noise, or a combination of these.
The recycling of construction and demolition waste (C&DW) is significant for both environmental protection and sustainable development. However, the dynamically evolving market environment poses new challenges to ...
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The recycling of construction and demolition waste (C&DW) is significant for both environmental protection and sustainable development. However, the dynamically evolving market environment poses new challenges to C&DW recycling. As C&DW recycling is increasing in scale and the market for recycled products is developing, the effectiveness of both enterprise decision-making and government regulation will be affected. Therefore, this study develops three differential game models based on different government subsidies to address the problem. Different from previous studies, this study considers how the reference green effect of consumers affects enterprise decision-making, and analyzes the evolution trends in the recycling rate over time. The result shows that: (1) When the initial recycling rate is given, the trajectory of recycling rate is monotonic and eventually tends to steady state. (2) Both government cost subsidy and recycled product subsidy can improve the recycling rate and enterprise profits. The optimal subsidy method depends on the subsidy coefficients. But recycled product subsidy is always better for consumers. (3) The reference green effect of consumers significantly influences the decisions of producers and recyclers. Producers and recyclers will make more efforts as the influence of the reference green effect on market demand increases. The adjustment rate of the reference green effect is negatively correlated with the efforts made by both participants. This study hopes to provide a theoretical support for government regulations and promote the development of the recycled products market.
A Sm2O3 decorated carbon aerogel (CA-Sm) was successfully synthesized through a sol-gel from resorcinol, phloroglucinol (P), formaldehyde and catalyst of oxalic acid and doping compound with Sm2O3 strategies. The smal...
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A Sm2O3 decorated carbon aerogel (CA-Sm) was successfully synthesized through a sol-gel from resorcinol, phloroglucinol (P), formaldehyde and catalyst of oxalic acid and doping compound with Sm2O3 strategies. The small amount of active reactant phloroglucinol promotes synthesis of carbon aerogel (CA) and formation of uniform and porous carbon spheres. The CA-Sm composites present an interlinked porous structure and high specific surface area. The CA-Sm with sulfur loading (CA/S-Sm) from the composite via molten sulfur technique exhibits an enhanced performance with long-term cycling stability and high rate capacity. In particular, the cathode of CA/S-Sm-2 with Sm/C molar ratio of 2/400 achieved a high initial discharge capacity of 1347 and 976 mAh g (1) at 0.2C and 2C, respectively. And the cathode exhibited a nice long-term cycling stability with a high initial discharge capacity of 1175 mAh g (1) and maintained 861 mAh g (1) after 300 cycles at 0.5C. The excellent electrochemical performance of the battery is attributed to interrelated nanospheres, porous carbon structure, large specific surface area of Sm2O3-doped CA composites and improved electronic and ionic transport at the cathode. (C) 2017 Elsevier Ltd. All rights reserved.
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