In order to improve the accuracy of the risk field model in predicting the lane-changing time of the driver in the weaving area of the freeway exit ramp, firstly, the driver behavior questionnaire survey method was used to cluster the driving style and lane-changing style, and the real vehicle driving test was carried out to obtain the vehicle lane-changing trajectory data and analyzed the risk perception level of different driving styles. Then, the derived traffic environment risk was introduced on the basis of the basic risk field model, and the risk field model was constructed from three aspects: road environment, traffic environment and management control, considering the factors such as driving style and traffic control. Finally, the vehicle lane change simulation control strategy and test were designed by combining the uniform acceleration (CA) motion model and the risk field model. The results show that the motor risk perception coefficients of cautious, ordinary and aggressive driving style drivers are 0.71, 1 and 1.17 respectively, and the distance risk perception coefficients are 0.62, 1 and 1.39 respectively. The risk intensity of driving style cautious type > ordinary type > aggressive type, and the critical lane change distance of driving style cautious type > ordinary type > aggressive type. The management control risk field model predicts that the threshold time of lane change decision for cautious, ordinary and aggressive drivers is 96.2 s, 105.2 s and 114.2 s, respectively, and the error is less than 1.5% compared with the simulation lane change time of 97.4 s, 104.8 s and 113.8 s.

In order to improve the emergency response capacity of urban flooding disasters, an emergency response capacity assessment model based on the combination of improved DS evidence theory and FBN was proposed. Firstly, from the whole process of disaster emergency management, the urban flood disaster emergency response capacity assessment index system was established and mapped into a Bayesian network (BN) model. Then, to address the problems of information uncertainty and strong subjectivity in the assessment process, the improved DS theory was introduced to determine the index weights. The expert knowledge combined with the fuzzy set was used to quantify the prior probability of the root node. The accident tree was applied to analyze the key indexes, and the Sorting center of mass method was used to assign basic event probabilities. The probability of flooding disaster risk was calculated through the BN model. Emergency response capacity assessment and reasoning analysis were carried out on the basis of the above results. Finally, take the main urban area of Zhengzhou city as an example, GeNIe4.0 software was used to generate the BN model of emergency response capacity assessment of flooding disaster, and the emergency response capacity level and sensitive indexes of flooding disaster in the city were obtained. The results show that the emergency response capacity of the main urban area of the city is good. The sensitive indicators affecting the emergency response capacity are timeliness of the emergency response, normality of the warning information release, professionalism of the emergency response and accuracy of flooding information feedback.

To analyze the synergistic relationship among urban emergency organizations during institutional reforms, 24 natural disaster-specific emergency plans from Xi'an city were used as the data sample. Social network analysis was employed to examine the coordination and collaboration between departments involved in emergency response, mitigation, and rescue during natural disasters. From a temporal perspective, the dynamic changes in the network structure were explored, and the characteristics of indicators such as density, centralization, and average distance were assessed. Using a "coherence and constraint" two-dimensional framework, institutional roles were classified and analyzed from three dimensions: institutional characteristics, functional positioning, and organizational structure. The CONCOR(Convergence of Iterated Correlation) algorithm and E-I index method were applied to depict the internal logic of network governance structures and the evolution of organizational relationships. The results show that the concentration of the emergency organization collaborative network increased from 0.577 6 to 0.723 5 after the institutional reform, indicating that the network structure shifts from a decentralized network with loose collaboration among multiple entities to a tightly-knit network centered around the Xi'an Bureau of Emergency Management. The highest core degree of institutions increases from 0.342 to 0.369, while the lowest constraint degree decreases from 0.166 to 0.087, reflecting a trend toward the unification of command responsibilities. The network organization follows a core-periphery governance structure, with the boundaries between core and peripheral organizations becoming increasingly clear and reinforced.

In order to reduce the incidence of unsafe behaviors and strengthen the effect of unsafe behaviors popularization, a novel golden monkey metaphor was constructed based on the conceptual integration theory. Taking the severity information and the metaphorical framework of unsafe behaviors as independent variables, the experimental process of the unsafe behaviors metaphor was designed to explore the influence mechanism and possible intermediary factors of golden monkey metaphor on unsafe behavior. The results show that golden monkey is a human-subjective, pervasive, and high-frequency unsafe behavior that results in relatively small transient losses. Low severity messages increase willingness to change behavior. The use of golden monkey metaphors to imply unsafe behaviors is more persuasive than nonmetaphors and increases willingness to change behavior. Severity and negative emotions play a suppression effect and a fully mediating effect between severity message and willingness to change behavior respectively, and degree of cognitive fine processing partially mediates the effect between metaphorical framing of unsafe behavior and willingness to change behavior.

In order to explore the effect of high fluid slurry materials on the micromechanical properties of coal, the transition area formed by different slurry materials and coal after grouting was scanned by scanning electron microscopy (SEM). Nanoindentation tests were carried out to analyze the effects of high fluid slurry materials on the microstructural characteristics and micromechanical properties of coal. Structural defects existed in the consolidated surface after grouting of ordinary cement materials. In view of this, the structural modification and mechanical strengthening mechanism of the transition area of the heterogeneous body were analyzed. The results show that the mechanical properties of the transition area between the high flow grouting material and the coal body are the weakest in the heterogeneous structure. This area is easy to break. The indentation modulus and indentation hardness in the transition zone between high flow grouting material and coal increase with the increase of mechanical properties of coal structure surface. After the ordinary cement grouting, the transition zone between the material and the coal body is large. The crystal density is low, there are obvious cracks between the material and the coal body, and the micromechanical properties are weak. After grouting, the high flow grouting material has close microstructure in the transition zone with coal. The transition zone with consolidated surface is small. Meanwhile, the interface transition zone (ITZ) has good micromechanical properties. These characteristics are helpful to improve the ability of gas extraction borehole deformation resistance.

In order to solve the problems of the high cost of multi-channel video data collection and long-term high-quality annotation in high-rise buildings or complex open building environments, the generation of multi-channel video data across the field of view and the automatic annotation of pedestrian images was realized. Firstly, a virtual reality scene was designed to simulate pedestrian movement and automatically obtain marker data. Secondly, unsupervised domain adaptation methods were researched to reduce the difference in feature distribution between source and target domain data, enabling the model to generalize to the target building scene. Finally, the model's generalization ability was verified. Results show that the constructed virtual reality scene effectively overcomes the difficulties of cross-visual video data collection and high-quality annotation. The unsupervised domain adaptation method increased the average first hit rate from 22.02% to 45.48%. By combining source domain style conversion, data augmentation, and target domain pseudo label generation, the first hit rate has been increased by 20%, reducing distribution bias and achieving generalization of the model in different building scenarios.

To investigate the occurrence characteristics of the tailings deposit and slurry flow behavior during the damming process of tailings impoundments, the flume test model was used to carry out the fine-grained tailings accumulation damming test under single pipe slurry discharge conditions. The variation characteristics of beach slope, tailings particle size distribution, water level height and pore water pressure during the accumulation process of fine-grained tailings were studied. The tailings slurry flow and trajectory characteristics were analyzed, and the mechanism of tailings refinement along the deposition course was discussed. The results show that deposition slope decreased with the increase of the downstream distance. The particle size of tailings gradually becomes finer with increase of downstream distance, and the particle size is staggered with the increase of depth. The height of water level of tailings dam increases with the increase of height of dam, exhibiting a steep front slope and a gentle back slope overall. The pore water pressure rises during the discharge stage of tailings slurry and dissipates during the intermittent stage when tailings slurry stops discharging. The tailings slurry flows in a fan-shaped divergent pattern at the beginning of flume, in an irregular stream-like pattern in the middle section, and transitions from laminar flow to irregular rotational flow at the end. The slurry flow rate on dry beach surface fluctuates greatly, and slurry movement tends to be stable after reaching the tailings water surface. There is a significant difference in slurry movement characteristics before and after the interface between dry beach and tailings water.

To explore the potential early warning value of construction safety hazard data and improve the efficiency of hazard identification and control, this study investigated a data-driven approach for the association analysis and early warning strategy of construction safety hazards by integrating text mining, association rule mining, and complex network theory. First, 1 405 construction safety inspection records in 2023 were standardized and dimensionally reduced using text mining techniques, resulting in the extraction of 67 safety hazard features. Then, 70 frequent itemsets and 125 strong association rules were obtained using the Apriori algorithm, and the types of hazard associations were identified. Subsequently, a hazard feature network was constructed based on complex network theory. Key hazard features were identified through structural and node-level indicators, combined with feature modularity analysis. Finally, a feature-driven early warning strategy was proposed. The results show that text mining effectively reduces the dimensionality of unstructured hazard data. The hazard feature network based on association rules successfully reveals hidden associations within the data and enhances the reliability of early warning information, providing clear direction and reference for on-site hazard detection. The early warning strategy helps address the issues of disorder and inefficiency in traditional hazard inspections.

In order to investigate and predict the internal failure and instability characteristics of gas hydrate coal samples under triaxial action, laboratory triaxial compression tests were first conducted based on the gas hydrate solidification method. Using scanning electron microscope(SEM) images as reference, composite Clump particle templates were constructed to establish biaxial compression models through discrete element method (DEM). The models were featured different particle shapes (irregular and spherical) and saturation levels (40%, 60%, 80%), followed by simulated triaxial compression tests. A comparative analysis was then performed from both macroscopic and mesoscopic perspectives to examine the effects of Clump particles versus spherical particles on the mechanical behavior of gas hydrate-bearing coal. The results demonstrate that the peak strength of specimens increases with hydrate saturation for both particle shapes. The enhancement becomes less pronounced at higher saturation levels. Irregular particle specimens exhibit significantly greater strength than spherical ones, with maximum strength improvement reaching 142.01%. Both saturation and particle shape show limited influence on failure modes. All specimens exhibit bulging failure and X-shaped shear band distribution. Spherical particle specimens display substantially more particle rotations and larger failure zones compared to irregular particles. During loading, irregular particles form stable load-bearing networks through interlocking, supported by their notably higher average coordination number than spherical particles. These findings confirm the superior performance of irregular particle models in characterizing the mechanical behavior of gas hydrate-bearing coal.

In order to evaluate the effectiveness of aerogel fire suppressants in preventing and controlling thermal runaway of lithium-ion batteries, this study selected aluminum-shell ternary lithium-ion battery cells and 18650 battery modules as experimental subjects. By employing differentiated fire suppression approaches (including application methods and operational parameters), comparative experiments on extinguishing efficacy were conducted in a systematic manner, with parallel comparisons to water-based fire suppression systems. The results show that the aerogel extinguishing agent has better fire extinguishing performance and cooling effect than water for different quantities of ternary aluminum-shell single lithium batteries and 18650 battery modules. For four ternary aluminum shell single lithium batteries, using water to extinguish fire will cause the battery temperature to rise to 492 ℃, which cannot quickly and effectively reduce battery temperature. The extinguishing speed of an aerogel extinguishing agent is 4.5 times that of water, and it can effectively prevent the battery from reburning. For 8 ternary aluminum shell single lithium batteries and two 18650 battery modules, the aerogel extinguishing agent still shows a good fire extinguishing effect, short fire extinguishing time, significant cooling effect and no reburning. Use of the aerogel extinguishing agent and fire extinguishing strategies of continuous spraying with large flow, small flow cooling after large flow spraying and spraying and flooding in containers have different fire extinguishing effects. Results show that the aerogel extinguishing agent can not only effectively extinguish initial battery fire, but also its preheating foaming mechanism and good foam stability can effectively reduce battery temperature and prevent further mixing of combustible gas and air.