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The article discusses the importance of accurate monitoring and early warning of heavy rainfall induced by strong convection for preventing natural disasters such as floods and landslides. It highlights the use of weather radars as the most powerful technique for monitoring natural hazards caused by heavy rainstorms. The article also covers various topics related to radar signal processing methods, error characterization, new sensing techniques, and the application of radar data in weather analysis and forecasting. It emphasizes the advancements in weather radar technology and its potential for revolutionizing meteorological forecasting and disaster preparedness. [Extracted from the article]

This study aimed to examine the mediating effect of life satisfaction in the relationship between hope and internalizing/externalizing behaviors among a sample of 1170 Chinese adolescents (mean age = 14.80 ± 1.76 years, 46.24% boys). Through the use of structural equation modeling (SEM), the study revealed a negative association between hope and internalizing/externalizing behaviors. Furthermore, the findings indicated that life satisfaction partially mediated the relationship between hope and internalizing/externalizing behaviors. The findings highlight the significance of hope and life satisfaction as protective factors in reducing internalizing/externalizing behaviors among adolescents. These results also contribute to the existing research on the role of hope and emphasize the importance of fostering hope and enhancing life satisfaction in prevention and intervention programs targeting adolescent internalizing/externalizing behaviors. [ABSTRACT FROM AUTHOR]

In this paper, to track maneuvering unmanned surface vehicles (USVs) in scenarios with clutter, we propose a novel method based on the probabilistic data association (PDA) algorithm and Rao-Blackwellized particle filter (RBPF) algorithm, and we further improve the tracking performance by Max-Q criterion-based waveform selection. This work develops a maneuvering target model in the context of clutter, integrating linear and nonlinear states as well as observations with false alarms. In order to jointly tackle the mixed-state tracking problem, the PDA algorithm is integrated into the RBPF framework. This allows it to be used with the complex nonlinear and linear hybrid system and helps to minimize the state dimensions of conventional particle filtering (PF). Additionally, by utilizing Q-learning principles, we provide a Max-Q-based criterion to select the waveform parameters, which guarantees low measurement errors and efficiently handles measurement uncertainties. Our simulation results show that the PDA-RBPF algorithm, which has a more appropriate tracking mechanism, produces results that are more accurate than those of the EKF or PF algorithms alone. Furthermore, the RMSE derived by the Max-Q-based criterion is smaller and more robust than that of other selection methods, as well as yielding a fixed waveform. Our proposed mechanism, which combines the concepts of PDA-RBPF and Max-Q waveform selection, performs well in target tracking tasks and exhibits relatively good performance over some existing ones. [ABSTRACT FROM AUTHOR]

Significant efforts have been expended for improved characterization of hydraulic conductivity (K) and specific storage (Ss) to better understand groundwater flow and contaminant transport processes. Conventional methods including grain size analyses (GSA), permeameter, slug, and pumping tests have been utilized extensively, while Direct Push‐based Hydraulic Profiling Tool (HPT) surveys have been developed to obtain high‐resolution K estimates. Moreover, inverse modeling approaches based on geology‐based zonations, and highly parameterized Hydraulic Tomography (HT) have also been advanced to map spatial variations of K and Ss between and beyond boreholes. While different methods are available, it is unclear which one yields K estimates that are most useful for high resolution predictions of groundwater flow. Therefore, the main objective of this study is to evaluate various K estimates at a highly heterogeneous field site obtained with three categories of characterization techniques including: (1) conventional methods (GSA, permeameter, and slug tests); (2) HPT surveys; and (3) inverse modeling based on geology‐based zonations and highly parameterized approaches. The performance of each approach is first qualitatively analyzed by comparing K estimates to site geology. Then, steady‐state and transient groundwater flow models are employed to quantitatively assess various K estimates by simulating pumping tests not used for parameter estimation. Results reveal that inverse modeling approaches yield the best drawdown predictions under both steady and transient conditions. In contrast, conventional methods and HPT surveys yield biased predictions. Based on our research, it appears that inverse modeling and data fusion are necessary steps in predicting accurate groundwater flow behavior. Article impact statement: Evaluating K from various approaches showed that inverse modeling and data fusion are necessary steps in building robust groundwater models. [ABSTRACT FROM AUTHOR]

The intense pulsed current superimposed on direct current arc discharges can promote arc spot splitting and reduce macroparticle ejection. In this study, the effects of different arc parameters including peak current, magnetic fields, pulse frequency and duty cycle on spot splitting characteristics for the pulsed cathodic arc discharge, as well as mechanisms involved in microspot formation, are investigated. The results show that under the effect of periodic micro-explosive emissions, the micro-spot splitting at the peak of the pulse displays a multi-stage annular expansion phenomenon, and its expansion radius increases with the increaseing peak current; the increasing transverse component of the arc source magnetic field gradually changes the microspot splitting pattern from annular expansion to arc-shaped expansion; the plasma motion after the micro-explosion requires a period of time to "accumulate force." In addition, an increase in pulse frequency leads to a gradual reduction in the range of the microspot splitting, in which the microspots are in a relative aggregation state; an increase in duty cycle, leads to an instability in the continuous motion of the microspots after the splitting in the peak period. This causes some of the microspots to merge, exhibiting a trend similar to the direct current arc. • This work aims to explore the dynamic evolution of the internal structure and motion of the pulsed cathodic arc spot under different discharge parameters, and the effects of different parameters on the characteristics of the arc spot formation and splitting motion are analyzed. • In this study, the effects of different arc parameters including peak current, magnetic fields, pulse frequency and duty cycle on spot splitting characteristics for the pulsed cathodic arc discharge, as well as mechanisms involved in microspot formation, are investigated. • The innovation we proposed looks to investigate the cathode arc spot's internal structure and splitting mechanism. We used the coupling theory of thermal field emission and electron explosive emission to analyze the phenomenon of microspot pulsed splitting observed at the microscopic level. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-ligand strategy was proposed to design high-efficient MOF photocatalysts. • The three-ligand MOFs, EY/NH 2 /H-MIL-125, were synthesized to verify our strategy. • The optimal three-ligand MOF can yield H 2 of 2.15 mmol g−1 h−1 under visible light. • Electron transfer is enhanced by a push–pull effect induced by the NH 2 -H 2 BDC and H 2 BDC ligands. • The third ligand EY facilitates the electron photoexcitation under visible light. The design and construction of high-performance photocatalysts with both strong visible light harvesting and effective electron transfer are highly desired in the photocatalysis field. Herein, a multi-ligand strategy based on the MOF materials is proposed. A three-ligand Ti-MOF EY/NH 2 /H-MIL-125 (ENHM) was prepared via a facile hydrothermal method, in which 2-aminoterephthalic acid (NH 2 -H 2 BDC), terephthalic acid (H 2 BDC) and Eosin Y (EY) were employed as three ligands. The push–pull effect induced by different substituent groups (–NH 2 and –H) on the skeleton of NH 2 -H 2 BDC and H 2 BDC promotes the efficient transfer of photogenerated electrons from organic ligands to metal nodes; while the third ligand EY increases the number of photoexcited electrons by enhancing the visible light absorption ability. Among the three-ligand MOF photocatalytic materials, ENHM-2 performs the optimal H 2 production activity of 2.15 mmol g−1 h−1, much higher than dual-ligand NH 2 /H-MIL-125 and EY/NH 2 -MIL-125 and single-ligand NH 2 -MIL-125. A probable mechanism was also proposed for the three-ligand MOFs. This multi-ligand strategy may open up a new direction toward the preparation of MOF-based photocatalytic materials with excellent photocatalytic performances. [ABSTRACT FROM AUTHOR]