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In coal fire control, grouting/water extinguishing is often repeated for reasons such as re-ignition. The surrounding rock undergoes repeated heating and water cooling, resulting in strength reduction and damage, and collapse and cracks on the extended surface, resulting in potential safety hazards. Therefore, the change of rock mechanics under high temperature and cold cycle after peak is studied. Taking sandstone as the research object, the ultrasonic wave velocity and water absorption rate of rock samples were tested, and the uniaxial compression test was carried out. The mechanical damage characteristics of sandstone were analyzed, and its energy consumption evolution law was further explored. The results show that: from 500 ℃ after the peak, the attenuation rate of ultrasonic wave velocity and the change rate of water absorption of rock samples change from positive to negative, the wave velocity decreases and the water absorption increases; 500 ℃ is the threshold temperature of mechanical sudden change of high-temperature rock sample after the peak, and then the peak point of stress-strain curve moves rapidly to the right, the peak stress declines greatly, and the initial thermal damage caused by cold and hot cycles intensifies, and the ductile failure is obvious; the evolution characteristics of energy consumption are different in different stages of rock samples under pressure. From 500 ℃ after the peak, the proportion of dissipated strain energy before the peak is gradually larger than that of elastic strain energy, and the dissipated strain energy is negatively correlated with the mechanical strength.

With the acceleration of the pace of society, the problem of scarcity of time resources is becoming more prominent, which may lead to short‐sighted behavior. This study aimed to examine the impact of time scarcity on intertemporal choice and its underlying mechanisms through three experiments. Study 1 aimed to investigate the causal relationship between time scarcity and intertemporal choice and the mediating role of anxiety between time scarcity and intertemporal choice. The results showed that participants with a stronger perception of time scarcity were more likely to choose smaller and sooner gains, and that the mediating role of anxiety was significant. In Study 2, the control of time was introduced to explore whether the sense of control could alleviate the negative emotion caused by time scarcity. The results showed that individuals with high levels of control had significantly less anxiety under higher time‐scarcity conditions than those with low levels of control. In Study 3, we manipulated time scarcity and found that the sense of control moderated the mediating effect of anxiety in time scarcity and intertemporal choice. Overall, these findings suggest that the sense of control over time is associated with less anxiety from time scarcity, which in turn fosters preferences for delayed gains. [ABSTRACT FROM AUTHOR]

With the frequent occurrence of drone black flying in large stadiums and airports, the requirement of precise electromagnetic interference to achieve unmanned aerial vehicle (UAV) displacement and forced landing in these protected area became urgent. Since traditional suppression jamming will affect normal communication, and forwarding deceptive jamming has coverage hole, a smart forwarding deceptive jamming distribution optimal algorithm (SFDJDO) is proposed. It gives a mapping error scale factor and the optimal distribution of multistation forwarding equivalent mapping to solve the problem of distortion on the mapping scale caused by different distribution methods and reduces the influence of the mapping errors and the differences between the virtual and real point neighborhoods of the jamming source. A comparison of the proposed SFDJDO method to the existing jamming source distribution optimisation method is conducted in the aspect of area mapping and trajectory mapping. The findings reveal that when the GNSS receiver clock bias is within the capture range, SFDJDO demonstrates significant enhancements in mapping precision and jamming success rates. [ABSTRACT FROM AUTHOR]