This paper describes a novel method of enhancing deep-sea optical images using guided local Laplacian filter. Absorption and are two major distortion issues for deep-sea optical imaging. While light traveling through the water, light rays are scattered and absorbed depending on the wavelength. Scattering is caused by large suspended particles, as in turbid water that contains abundant particles, which causes the degradation of the captured image. Absorption corresponds to the varying degrees of attenuation encountered by light traveling in water at different wavelengths that causing ambient underwater to be dominated by a bluish tone. Our key contributions are proposed include a novel deep-sea imaging model to compensate for the attenuation discrepancy along the propagation path and an effective underwater scene enhancement scheme. The recovered images are characterized by a reduced noised level, better exposure of the dark regions, and improved global contrast where the finest details and edges are enhanced significantly.
Alkaline membrane water electrolysis is a promising production technology, and advanced electrocatalyst and membrane electrode design have always been the core technology. Herein, an ion-exchange method and an environmentally friendly in situ green phosphating strategy are successively employed to fabricate Ru-Ru2P heterogeneous nanoparticles by using hydroxyapatite (HAP) as a phosphorus source, which is an exceptionally active electrocatalyst for hydrogen evolution reaction (HER). Density functional theory calculation results reveal that strong electronic redistribution occurs at the heterointerface of Ru-Ru2P, which modulates the electronic structure to achieve an optimized hydrogen adsorption strength. The obtained Ru-Ru2P possesses excellent HER performance (24 mV at 10 mA cm−2) and robust stability (1000 mA cm−2 for 120 h) in alkaline media. Furthermore, an environmentally friendly membrane electrode with a sandwich structure is assembled by HAP nanowires as an alkaline membrane, Ru-Ru2P as a cathodic catalyst, and NiFe-LDH as an anodic catalyst, respectively. The voltage of (−) Ru-Ru2P || NiFe-LDH/CNTs (+) (1.53 V at 10 mA cm−2) is lower than that of (−) 20 wt% Pt/C || RuO2 (+) (1.60 V at 10 mA cm−2) for overall water splitting. Overall, the studies not only design an efficient catalyst but also provide a new route to achieve a high-stability electrolyzer for industrial H2 production. 相似文献