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Wireless sensor networks often rely on battery power, which incurs high costs, considerable volume, and a limited lifespan. Additionally, the communication range of existing passive sensor tags remains short, which challenges their suitability for evolving Internet of Things (IoT) applications. This paper, therefore, presents a long-distance passive RFID sensing tag that integrates multi-source energy harvesting and reflection amplification. Multi-source energy harvesting enhances tag receiving sensitivity and extends the system's downlink communication distance, while reflection amplification increases tag reflection power and improves the uplink communication distance, thereby significantly expanding the overall communication range. The test results show that the tag achieves a receiving sensitivity of -45 dBm, a reflection gain of 44 dB, and a communication distance of up to 96 m.
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http://dx.doi.org/10.3390/mi16010018 | DOI Listing |
J Acoust Soc Am
September 2025
School of Ocean Engineering and Technology, Sun Yat-sen University, Zhuhai 519000, China.
This study establishes a quantitative framework using field observations and normal mode theory to reveal wind field control mechanisms over ambient noise vertical directionality in shallow water. Acoustic data from a vertical line array in the northern South China Sea, combined with sound speed profiles, seabed properties, and multi-source wind fields (ERA5 reanalysis/Weibull-distributed synthetics), demonstrate: (1) A 20-km spatial noise-energy threshold (>90% energy contribution), challenging conventional near-field assumptions (1-2 km); (2) frequency-dependent distribution: low-frequency (50-200 Hz) directionality depends on near-field sources, while high-frequency (>400 Hz) energy shifts seaward due to modal cutoff variations; (3) model validation shows 0.96 correlation at 100 Hz/100 km (stratified medium accuracy), but seabed interface waves induce 3.
View Article and Find Full Text PDFSensors (Basel)
August 2025
School of Mechanical Engineering, Dalian Jiaotong University, Dalian 116028, China.
In response to the instability fluctuations and erosion characteristic changes in pantograph-catenary system (PCS) arcs induced by humidity variations in an open environment, a single-variable controlled experimental approach based on multi-source data fusion is proposed. This study innovatively establishes a humidity-controlled reciprocating current-carrying arc initiation test platform, integrating digital image processing with the dynamic analysis of multi-physics sensor signals (current, voltage, temperature). The study quantitatively evaluates the arc motion characteristics and the erosion effects on the frictional contact pair under different relative humidity levels (30%, 50%, 70%, and 90%) with a DC power supply (120 V/25 A).
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August 2025
School of Advanced Manufacturing, Nanchang University, Nanchang 330031, China.
In the field of intelligent manufacturing, image anomaly detection plays a pivotal role in automated product quality inspection. Most existing anomaly detection methods are adept at capturing local features of images, achieving high detection accuracy for structural anomalies such as cracks and scratches. However, logical anomalies typically appear normal within local regions of an image and are difficult to represent well by the anomaly score map, requiring the model to possess the capability to extract global context features.
View Article and Find Full Text PDFJ Environ Sci (China)
December 2025
Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China. Electronic address:
Temperature plays a crucial role in shaping microbial ecosystems during anaerobic digestion. However, the specific microbial communities and their functions across a wide temperature range still remain elusive. This study employed a genome-centric metagenomic approach to explore microbial metabolic pathways and synergistic networks at temperatures of 35, 44, 53, 55, and 65 °C.
View Article and Find Full Text PDFSci Rep
August 2025
Department of Electrical Power and Control Engineering, School of Electrical Engineering and Computing, Adama Science and Technology University, Adama, Ethiopia.
Ensuring stable frequency regulation in islanded airport microgrids is a challenging task owing to the intermittency of renewable energy sources, unpredictable load variations, and nonlinear dynamics. Conventional optimization techniques often struggle with premature convergence and sub-optimal controller tuning, leading to a poor transient response and inadequate frequency stabilization. These challenges necessitate an advanced optimization strategy that can efficiently handle dynamic airport environments while ensuring enhanced frequency stability.
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