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We study theoretically the features of the output field of a quadratically coupled optomechanical system assisted with three-level atoms. In this system, the atoms interact with the cavity field and are driven by a classical field, and the cavity is driven by a strong coupling field and a weak signal field. We find that there exists a multi-window transparency phenomenon. The width of the transparent windows can be adjusted by controlling the system parameters, including the number of the atoms, the powers of the lasers driving the atoms and driving the cavity, and the environment temperature. We also find that a tunable switch from fast light to slow light can be realized in this system.

This work demonstrates a facile method for the synthesis of a "green" photocatalyst for efficient solar degradation of toxic colorants in polluted water. CeO 2 nanofiber crystals were fabricated by electrospinning and thermal tuning at 500−1000 °C. It was found for the first time that the photocatalytic performance of pure CeO 2 was improved by simple thermal tuning. Without incorporating any potentially harmful impurities, the pure CeO 2 nanofiber crystals degraded up to 97.6% methylene blue (MB) in 180 min under simulated solar irradiation. Further, the CeO 2 nanofiber crystals demonstrated an excellent long-term recycling stability with less than 1% activity fluctuations in 10 cycles. The improved photocatalytic performance was attributed to the small crystal size, clean crystal surface, and plenty of oxygen vacancies of CeO 2 . SEM and TEM observations showed that the average fiber diameter decreased while the particle size increased with tuning temperature. FTIR revealed that the surface-adsorbed organic moieties decreased with the increase of temperature, making active sites more accessible for photocatalysis. The presence of oxygen vacancies was confirmed by both Raman and XPS, which were critical for the activation of oxygen in photocatalysis. Our pure CeO 2 photocatalyst is eco-friendly and inexpensive for large-scale application for the removal of toxic colorants to fulfill environmental sustainability.

The combined effect of sodium erythorbate, stable chlorine dioxide, and gellan gum glazing on quality of peeled shrimp was investigated during frozen storage, and compared with traditional water‐ice‐glazing treatment. Data revealed that the growth of total aerobes, Escherichia coli, and Staphylococcus aureus was significantly inhibited in the combined treatment, compared to the water‐ice‐glazing group. Examination of tissue texture and microstructure verified that the combined glazing effectively maintained springiness and chewiness of the shrimp muscle, and this treatment showed a positive effect on stability and integrity of tissue microstructures. Myofibrillar protein content and Ca2+‐ATPase activity in muscle treated with combination were significantly higher than the water‐ice‐glazing treatment. SDS‐PAGE results confirmed that this treatment markedly slowed the degradation of muscle proteins. Additionally, the combined treatment significantly decreased the amount of protein carbonyls and dityrosine, which was mainly governed by the anti‐oxidization effect of incorporated sodium erythorbate. Practical applications Ice‐glazing is a surface coating process and is especially useful in the field of shrimp preservation, which prevents incidence of surface drying and dehydration, freezer burn, oxidation, and/or rancidity. However, the traditional water‐ice‐glazing can lead to cracking and sublimation during long period of frozen storage. The bacterial contamination cannot be completely suppressed or inactivated by the single ice‐glazing treatment. Among glazing processes, chitosan‐based glazings have been most widely studied to maintain quality of shrimp products. However, chitosan is water‐insoluble, relatively expensive, and highly viscous, which greatly limits its practical applications. For these reasons, alternative treatments that can form a stable and uniform glaze on surface of shrimp should be considered to minimize bacterial contamination and inhibit quality deterioration of frozen products. Outcome of the current study provides information regarding an optimum glazing formulation for shelf‐life extension of shrimp during frozen storage.