Global warming is significantly altering the patterns of extreme weather events, with extreme heat exerting an especially urgent impact on densely populated urban agglomerations. This paper focuses on Guangzhou, a core city in China's Pearl River Delta (PRD), as a representative case. Based on monthly maximum temperature data from 1970 to 2020 provided by the U.S. National Oceanic and Atmospheric Administration (NOAA), this study analyzes the long-term characteristics of summer high temperatures in this region. It shows that over the past 51 years, the average summer (June-August) maximum temperature in Guangzhou has exhibited a significant upward trend, with a linear warming rate of approximately 0.25°C per decade. Further research reveals that warming is asynchronous across the summer months, with August showing the most pronounced warming rate. This trend serves as the fundamental climatic background for the increasingly frequent and intensified extreme high-temperature events in the PRD region. Integrating existing literature, this paper demonstrates that continued warming poses compound risks to regional public health, the ecological environment, and socio-economic functioning through multiple pathways, such as intensifying the urban heat island effect, altering the ecology of infectious disease vectors, and increasing the potential for photochemical pollution.

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The airfoil is prone to flow separation under low Reynolds number flow conditions, which leads to a sharp deterioration of aerodynamic performance of micro aircraft. This paper proposes a bionic separation flow airfoil design concept, which turns to fix the separation point through the leading edge sharpening structure and induce stable vortices, combined with the rear edge arc airfoil surface to promote flow reattachment and vortex stability. Numerical simulation results show that This bionic airfoil can effectively suppress flow separation over a wide Angle of attack (8°-16°), significantly increase lift coefficient, significantly improve stall characteristics, and extend the efficient operating range by about twice compared to traditional airfoils. Parameter analysis reveals the influence of key geometric parameters such as the leading edge tip Angle and the installation position of the arc wing on aerodynamic performance.

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Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and its prevalence continues to increase. Acute exacerbation (AECOPD) is a critical step in the progression of the disease, leading to irreversible decline in lung function. Among existing preventive measures, inhaled bronchodilators only alleviate symptoms and fail to reduce the risk of infection-related exacerbations. Vaccines do not cover multiple pathogens, and prophylactic antibiotics are prone to inducing drug resistance, all with obvious limitations. This study reviews the immunomodulatory mechanisms and clinical efficacy of bacterial lysates. High-quality literature from 2020 to 2025 was selected for qualitative and comprehensive analysis. The aim is to clarify the core mechanism of action and clinical efficacy of these lysates in preventing AECOPD, and to provide evidence-based support for clinical practice. The reviewed studies demonstrate that bacterial lysates can significantly reduce the incidence and hospital admission rate of AECOPD by synergistically regulating innate and adaptive immunity and strengthening the respiratory mucosal barrier, thereby reducing antibiotic use. They also have favorable safety and tolerability, providing evidence-based support for clinical practice and are expected to become an important means of AECOPD prevention.

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In modern society, background music is often used as a tool to promote learning during the learning process, but in fact, there is still widespread controversy over the effect of music. The present study investigates how music is perceived to influence concentration, with a focus on influential factors and text types. Fifty-one participants completed an anonymous questionnaire assessing music-listening behaviors, music preferences, and perceived effects of music on concentration and task performance. By using composite indices, the data shows that music can facilitate individuals' concentration overall and are influenced by music elements and text types; in contrast, the interference caused by music on attention are mainly determined by individuals' differentiation. These findings suggest that music functions depend more on how it is used and the task context than on specific musical characteristics and provide adolescents referenceable data for the use of music.

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