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Fallen trees enter the adjacent stream and are carried away downstream by the current. As the stream joins another one, the complex hydrodynamics near their confluence make the movement of wood hard to predict. These woods may accumulate near the confluence resulting in backwater and subsequent potential flooding. A laboratory study was conducted to investigate the movement and accumulation behavior of individual pieces of wood near the confluence. The characteristics of wood (i.e., the length, diameter, and density) and the hydraulic conditions (i.e., the discharge ratio and the release distance) were varied in this investigation. It was found that the wooden pieces released from the tributary got occasionally trapped in the flow separation zone of the confluence, whereupon they were mainly trapped by a clockwise vortex and continued to stay driven by a reverse cluster of currents within this zone. The accumulation probability of wood was mainly related to its length, the discharge ratio and the release distance. The effect of wood diameter and density within the tested parameters was negligible. The probability increased with an increase in the discharge ratio as well as a decrease in the release distance. The longer pieces had a higher probability of being trapped, whereas for those exceeding some critical value, the probability was nearly the same, or dropped sharply. A generalized model for wood accumulation near the confluence was developed for practical application. These findings carry significant implications for river management, particularly in preventing the risk of flooding caused by wood blockage. Key Points: Conducting a laboratory study to investigate the transport, accumulation and trapping mechanism of wood near the confluenceEvaluating the wood accumulation probability depending on different wood characteristics and confluence hydrodynamic conditionsWood released from the tributary may be trapped by the clockwise vortex and thus accumulate in the separation zone [ABSTRACT FROM AUTHOR]

The meticulous design of active sites and light absorbers holds the key to the development of high-performance photothermal catalysts for CO2 hydrogenation. Here, we report a nonmetallic plasmonic catalyst of Mo2N/MoO2-x nanosheets by integrating a localized surface plasmon resonance effect with two distinct types of active sites for CO2 hydrogenation. Leveraging the synergism of dual active sites, H2 and CO2 molecules can be simultaneously adsorbed and activated on N atom and O vacancy, respectively. Meanwhile, the plasmonic effect of this noble-metal-free catalyst signifies its promising ability to convert photon energy into localized heat. Consequently, Mo2N/MoO2-x nanosheets exhibit remarkable photothermal catalytic performance in reverse water-gas shift reaction. Under continuous full-spectrum light irradiation (3 W·cm−2) for a duration of 168 h, the nanosheets achieve a CO yield rate of 355 mmol·gcat−1·h−1 in a flow reactor with a selectivity exceeding 99%. This work offers valuable insights into the precise design of noble-metal-free active sites and the development of plasmonic catalysts for reducing carbon footprints. In this work, the authors design a Mo2N/MoO2-x nonmetallic plasmonic catalyst by regulating synergy between two specific active sites. Highly efficient, selective, and durable CO2 hydrogenation under relatively mild reaction conditions is achieved [ABSTRACT FROM AUTHOR]

High-frequency and timely tourism demand forecasting of fine-grained attractions is an effective tool that helps tourism stakeholders make decisions and formulate strategies. However, there are limitations due to the external sensitivity of tourism demand. This research integrated news coverage with other psychosocial variables to comprehensively explore the impact of social unrest on tourism demand. Topic modelling was applied to identify tourism news topics and potential meanings. Sentiment classification was used to convert news into structured data. Sentiment indices and quantities constituted a composite news term. The empirical results showed that the comprehensive inclusion of external elements, especially news coverage, can significantly improve the prediction performance. K-Nearest Neighbour with the news term yielded the best results. [ABSTRACT FROM AUTHOR]

Nb3O7(OH) containing abundant surface lattice hydroxyl groups, combining with loaded Au nanoparticles as the cocatalyst, was employed as a photocatalyst enabling highly efficient photocatalytic CH4 coupling to C2H6 under mild conditions. In situ spectroscopy technique revealed that the surface lattice hydroxyl groups play a vital role in promoting the activation of CH4 to produce the methoxy intermediates, contributing to significantly enhanced catalytic performance for CH4 conversion. [ABSTRACT FROM AUTHOR]

The asymmetric radio frequency (RF) self‐interference cancellation (SIC) architecture is studied, and the closed‐loop control of RF SIC based on software radio is realized. This system uses a circulator to isolate the receiving and transmitting chains, and its RF reconstruction chain is composed of a 4‐tap filter with fixed delay and tunable attenuation for each tap. The optimization of tap filter and asymmetric power divider's power allocation ratio is discussed. In the experiment, sensing, calibration, optimization algorithms and hardware control programs were proposed. A closed‐loop gradient descent algorithm for tuning the variable attenuator is implemented on the GNU Radio. From 910 MHz to 930 MHz, the isolation between the receiving and transmitting ports increases 40 dB, achieving an isolation of more than 65 dB and the transmission energy efficiency increases by 60%. [ABSTRACT FROM AUTHOR]