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Objective With the rapid development and expansion of urban rail transit, the problem of noise pollution is increasingly prominent due to the continuous extension of train operation lifespan. This not only causes severe harm to passenger riding experience and health, but also directly affects the brand image and service quality of rail transit enterprises. Therefore, it is necessary to collect and monitor noise levels during train operation to implement targeted noise control measures, maximizing the effectiveness of noise mitigation efforts. Method With a combination of hardware and software resources such as noise sensors, STM32 microcontrollers, 4G transmission modules, Keil μVision5, Python, and OneNET cloud platform, an online noise monitoring system based on IoT (Internet of Things) is designed and developed specifically for urban rail transit trains. Result & Conclusion The system is successfully tested and validated on Kunming Metro Line 4, achieving real-time monitoring of train interior noise with advantages such as short sampling cycles, high data accuracy, and low data loss and latency rates. The system can issue timely alerts when noise levels exceed national standards, effectively meeting the design objectives. Additionally, the system can be applied to other environmental noise monitoring scenarios, providing reference for environmental noise treatment, enhancing the quality of life for residents, and promoting sustainable urban development.

This study explores the integration of X‐ray‐induced photochromism and photoluminescence in a single material, offering innovative multi‐mode applications in optical memory, anti‐counterfeiting, and X‐ray detection and imaging. The photochromic phosphor LiAlSi2O6:Sm3+ is synthesized, which undergoes a color change from white to dark green under bright field conditions and displays orange photoluminescence in dark field conditions after X‐ray exposure due to defect formation. The phosphor shows accelerated bleaching and recovery under 473 nm laser stimulation. The distinct X‐ray‐induced color contrast and luminescence intensity modification in LiAlSi2O6:Sm3+ highlight its potential in advanced luminescent material design. Moreover, a LiAlSi2O6:Sm3+‐based flexible film demonstrates "dual‐mode" 3D X‐ray imaging and detection capabilities, paving the way for future X‐ray detecting and imaging device research. [ABSTRACT FROM AUTHOR]

Sediment sources and sinks are an effective reflection of the comprehensive management of soil and water conservation in a watershed. However, human interference has made the sediment transport process in watersheds more complex. Research that distinguishes hillslopes and channels to reveal changes in sediment sources and sinks within a watershed and the relationships with key driving factors requires strengthening. In this study, the characteristics of sediment sources and sinks on hillslopes in the Mahuyu watershed, located on the Loess Plateau, were simulated using the Revised Universal Soil Loss Equation model and hillslope sediment delivery ratio model. Furthermore, variations in channel scour and siltation at the event scale were analysed based on the simulated hillslope sediment yield and measured sediment yield at the outlet station. Additionally, the principal hydrological driving factors affecting the sediment yield at the outlet were explored. The results show that 66 sediment yield events occurred in the Mahuyu watershed during the period 2006–2018, and channel sediment yield has emerged as the leading contributor to the watershed sediment yield, accounting for a minimum of 69.8%. There is also a marked decoupling between hillslope sediment yield and watershed sediment yield in the Mahuyu watershed. Furthermore, the maximum daily average streamflow is identified as the critical driving factor responsible for determining the watershed sediment yield, indicated by a coefficient of determination of 0.850. Therefore, we recommend that the future focus of soil and water conservation measures should be shifted from hillslopes to channels. [ABSTRACT FROM AUTHOR]

In order to analyze the thermal environment and its influence on workers’ thermal adaptation, a field study was conducted in a rubber factory during winter. Indoor and outdoor environmental parameters were measured and subjective questionnaire surveys were collected. The study was conducted from November to January the next year. During the survey, indoor temperature was in the range of 12.6 to 21.7°C and indoor air velocity ranged from 0.15 to 0.3 m/s. The clothing insulation during heating period was between 0.85-0.9 clo, while it was between 1.21-1.33 clo during pre-heating period. The estimated metabolic rate was around 2-2.2 met. Analysis showed that the thermal sensation vote (TSV) was higher than that predicted by PMV. The neutral temperature difference between TSV and PMV was 4.8°C. The thermal comfort and thermal adaptation of workers in winter were systematically analyzed and a thermal adaptive model was proposed. Basis on the adaptive model, the comfort temperature range of workers was suggested.

Local draft experiments were conducted to establish the overall thermal sensation prediction model under low pressure environment. Head, chest, hand, and ankle were exposed to local airflow under three pressure environments: 1 atm, 0.87 atm, and 0.74 atm, respectively. The skin temperature was measured and the subjective questionnaires were collected. The results showed that in cooler environment, the mean skin temperature decreased with the decrease of pressure, and people maybe more sensitive. When the environmental pressure decreased, the overall thermal sensation decreased correspondingly. Compared with the normal pressure condition, as the pressure decreased, the weight of local thermal sensation on overall thermal sensation changed a little. The weight of chest decreased while the weight of hands increased. When exposed to local draft, the four body parts showed similar influence on the overall thermal sensation under lower pressure conditions. Based on influence of pressure, temperature, and local draft speed, the overall thermal sensation prediction model for each body part was established respectively. The results indicated that the predicted values were highly correlated with the measured values. The models could be used to predict thermal sensation of people who are exposed to local draft in low pressure environment.

The reversible luminescence modification of inorganic phosphors has emerged as a promising field, enabling innovative applications such as optical memory, multiple anti‐counterfeiting, and photoswitches. Traditional luminescence modulation techniques, such as core–shell structure design and energy transfer‐related luminescent ions regulation, face challenges in achieving reversible luminescence modification. Chromism induces reversible color changes in materials when stimulated by external fields such as electricity, heat, and light. Combining chromism with luminescence enables the creation of chromism‐driven reversible luminescence manipulation in a single material. This review summarizes recent advances in reversible luminescence modification of inorganic phosphors based on chromism reaction and highlights their potential applications in optical data storage, fingerprint acquisition, and anti‐counterfeiting areas. The potential prospective research directions are also discussed and the challenges and opportunities of chromism‐based reversible luminescent materials are presented for further extended applications. [ABSTRACT FROM AUTHOR]

Double perovskite (DP) phosphors attract extensive attention due to their potential applications in the field of optoelectronics. Photochromism‐induced luminescence modulation can extend their application fields. However, designing and preparing DP phosphors with expected photochromic and luminescent properties is still challenging. Herein, the photochromic Ba2YTaO6: Yb3+, Er3+, Co2+ DP with upconversion luminescence properties is developed. The color of the sample turns from white to pink upon 254 nm UV light irradiation, which is fast fading upon 473 nm laser illumination. The mechanism of photochromism is related to the formation of color centers, and the doping of Co2+ ions is crucial for the improvement of photochromism, which is from the increasing of traps depth, the oxygen vacancies, and the carrier concentration of the matrix caused by Co2+ doping. The upconversion luminescence of Er3+ ions can be reversibly modulated by the photochromic effect, exhibiting excellent reproducibility and high stability. The potential application of photochromic Ba2YTaO6: Yb3+, Er3+, Co2+ phosphor is demonstrated in the field of anticounterfeiting and three‐dimensional (3D) artwork. This work not only offers insight into the photochromic mechanism of DP but also presents guidance for developing other photochromic DP phosphors. [ABSTRACT FROM AUTHOR]