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Abstract Restructuring of metal components on bimetallic nanoparticle surfaces in response to the changes in reactive environment is a ubiquitous phenomenon whose potential for the design of tunable catalysts is underexplored. The main challenge is the lack of knowledge of the structure, composition, and evolution of species on the nanoparticle surfaces during reaction. We apply a modulation excitation approach to the X-ray absorption spectroscopy of the 30 atomic % Pd in Au supported nanocatalysts via the gas (H2 and O2) concentration modulation. For interpreting restructuring kinetics, we correlate the phase-sensitive detection with the time-domain analysis aided by a denoising algorithm. Here we show that the surface and near-surface species such as Pd oxides and atomically dispersed Pd restructured periodically, featuring different time delays. We propose a model that Pd oxide formation is preceded by the build-up of Pd regions caused by oxygen-driven segregation of Pd atoms towards the surface. During the H2 pulse, rapid reduction and dissolution of Pd follows an induction period which we attribute to H2 dissociation. Periodic perturbations of nanocatalysts by gases can, therefore, enable variations in the stoichiometry of the surface and near-surface oxides and dynamically tune the degree of oxidation/reduction of metals at/near the catalyst surface.

Abstract Globally there is already a lot of pressure on water resources because of climate change, economic development, as well as an increasing global populace. Many rivers originate in the mountains, where snowfall fluctuations and the global climate’s inherent unpredictability affect the hydrological processes. Climate change sensitivity has been recognized in recent years and would affect hydropower, such as humidity, cloudiness, and precipitation, that are considered; global warming emerges as one of the most important contributors to climate change. The Yangtze River supports rich biodiversity and provides important ecosystem services for human survival and development. In addition, climate changes, particularly short-term and long-term precipitation and temperature fluctuations, influence the snow regime and the hydrological development of river flow response at the basin and sub-basin scales. More precise this review focused to understand the hydropower potential, freshwater fisheries, and hydrological response of snow dynamics in snow-dominated basins.

Under fatigue load, insulated gate bipolar transistor (IGBT) experience structural damage and performance degradation, imparting the reliability of power electronic systems. To address this, the relationship between solder layer fatigue crack length and thermal resistance is derived based on heat transfer theory, firstly. The Darveaux model is used to characterize the evolution law of solder layer cracks in IGBT, and a new IGBT performance degradation model along with a method for estimating its undetermined coefficients is proposed. Then, considering the non-stationary characteristics of actual working conditions, a variable amplitude fatigue load model for IGBT is established using the response surface methodology. The rain flow counting method and linear cumulative damage citation are then employed to assess the extent of IGBT performance degradation. Finally, using a type of IGBT product as an example, power cycling thesis are conducted, and performance degradation modeling and analysis are carried out based on experimental data, verifying the effectiveness of the models and algorithms. [ABSTRACT FROM AUTHOR]

Intense and prolonged physical activity can lead to a decrease in muscle capacity, making it difficult to maintain the desired exercise intensity and resulting in exercise fatigue. The long‐term effects of exercise fatigue can be very damaging to the body, so it is an urgent problem to be addressed. The intervention of foodborne active substances will be an effective measure. There is growing evidence that the molecular structure and function of curcumin have a positive effect on relieving fatigue. In this review, we summarize curcumin's molecular structure, which enables it to bind to a wealth of molecular targets, regulate signaling pathways, and thus alleviate exercise fatigue through a variety of mechanisms, including reducing oxidative stress, inhibiting inflammation, reducing metabolite accumulation, and regulating energy metabolism. The effects of curcumin on fatigue‐related markers were analyzed from the perspective of animal models and human models and based on the bidirectional interaction between curcumin and intestinal microbiota: Intestinal microbiota can transform curcumin, and curcumin regulates gut microbiota through metabolic pathways, providing a new perspective for alleviating fatigue. This review contributes to a more comprehensive understanding of the possible molecular mechanisms of curcumin in anti‐fatigue and provides a new possibility for the development of functional foods in the future. [ABSTRACT FROM AUTHOR]