Traffic conflicts caused by illegal riding of e-bikes are a great challenge and negative impact on the safety management and operation efficiency of signalized intersections. In this paper，three indexes including post-encroachment time (PET)，time to collision (TTC) and deceleration-to-safety time (DST) were selected from the two aspects of the number of collision objects and motion state. The k-means clustering was adopted to divide the severity of traffic collisions caused by illegal riding of e-bikes into three categories: general，serious and potential collision. Secondly，the Poisson function was used to fit the distribution characteristics of conflict frequency，random variables were introduced to describe the mixed effects of heterogeneity among traffic conflicts，and a prediction model for traffic conflicts of illegal riding e-bikes based on GLMM was built to predict the frequency of traffic conflicts of multi-grade severity. Combined with the data of 996 e-bike traffic conflicts obtained by video investigation，the empirical study shows that the proportion of e-bike traffic conflicts with different severity has nothing to do with the types of violations. The constructed GLMM model is better than generalized linear model (GLM) in fitting the traffic conflict data of illegal cycling e-bikes，and has the best prediction effect on the common conflict frequency. By strengthening the management of e-bike occupation of motor vehicle lanes and the waiting behavior of crossing the line，adding escort officers and adjusting the signal phase，the incidence rate of e-bike conflict can be reduced.

In order to reveal the sloshing behavior of vehicle-mounted liquid hydrogen storage tanks and improve their transportation stability，a numerical simulation model of vehicle-mounted liquid hydrogen storage tank sloshing was established. The impact of liquid hydrogen fluid sloshing on the storage tank during braking and turning was studied. The effects of driving speed，longitudinal and lateral acceleration and filling rate on the sloshing behavior of liquid hydrogen in the storage tank were discussed，and a wave-proof plate was designed to suppress the sloshing of liquid hydrogen. The results show that the stable driving speed of the vehicle has little effect on the liquid hydrogen sloshing in the tank. The more urgent the vehicle brakes or turns，the more severe the liquid hydrogen sloshing in the tank，the more serious the impact on the tank，and the longer the time required for the liquid hydrogen to reach a stable state. The closer the filling rate is to 50%，the more severe the sloshing is. As the filling rate increases to 90%，the impact of liquid hydrogen on the storage tank is more significant. However，the higher filling rate reduces the liquid hydrogen movement space and makes the sloshing amplitude more gentle. The anti-wave plate in the tank can effectively separate the liquid hydrogen sloshing space，so that the maximum longitudinal impact force of the tank is reduced by 9.6% and 17.5%，and the maximum lateral impact force is reduced by 34.6%，which significantly reduces the impact on the tank and shortens the liquid hydrogen recovery time.

To address the issue of predicting heat stress risks for police officers engaged in outdoor operations under high-temperature conditions，a test dataset for monitoring core temperature of police officers under different environmental working conditions，levels of physical exertion and clothing scenarios was constructed. First，features such as height，weight，age，gender，body fat percentage，physical activity ratio (PAR)，clothing insulation (CI)，environmental temperature and relative humidity were extracted. Then，machine learning methods，including K-nearest neighbors (KNN)，random forest (RF) and gradient boosting decision trees (GBDT)，were used to establish predictive models of core temperature and heat stress risk for outdoor police officers. These models were subsequently validated. The results indicate that for the predictive model of core temperature for outdoor police officers working in high-temperature environments，the goodness-of-fit measure R² exceeds 0.9 for KNN，RF and GBDT. In terms of error，the KNN model has the smallest prediction error，with a root mean square error (RMSE) of 0.053 ℃. For the heat stress prediction model for police officers engaged in outdoor operations under high-temperature conditions，the predictive performance of RF，GBDT and KNN models is significantly better than that of other models.

To investigate the evolution of overburden structure and the stability of district coal pillars during the mining of shallow-buried coal seam island faces，a study was conducted with the 50104 working face of Taihua coal mine as the engineering background. The research employed a combination of theoretical analysis，numerical simulation，and on-site measurement to analyze the load-bearing capacity of the district coal pillars and the characteristics of overburden structure evolution on both sides. The FLAC^3D numerical software was utilized to simulate the distribution of plastic zones and the evolution of mining-induced stress. The results indicate that during the advancement of the 50104 working face，the plastic destruction of the district coal pillars on both sides lagged behind the progress of the working face. The district coal pillars located in the goaf area behind the working face were in a state of plastic destruction，while those in front of the working face coal wall maintained a stable elastic zone，overall remaining stable. Throughout the working face advancement，the stress distribution of the district coal pillars on both sides exhibited the same characteristics，with two 11 m coal pillars showing symmetric high-stress concentration areas，both located behind the working face. The development speed of the high-stress destruction area of the district coal pillars lagged behind the advancement speed of the working face. The average stress value in the central area of the district coal pillars in front of the working face increased from 3.35 MPa to 3.54 MPa，but it never exceeded the coal pillar bearing capacity value calculated theoretically. Analysis of the mine pressure monitoring data from the 50104 working face revealed that the average initial support force was 3 932.4 kN，accounting for 55% of the rated initial support force of hydraulic support. The average maximum working resistance was 5 812.3 kN，representing 61.2% of the rated working resistance. The weighted average resistance was 4 836.6 kN per support，which is 50.9% of the rated working resistance. The maximum pressure was 6 013 kN，with a support stress of about 2.35 MPa，proving the stability of 11 m coal pillars and indicating that the overall stability of the district coal pillars in front of the working face coal wall is relatively good.

In order to better use microwave antireflection technology to safely and efficiently extract coal seam gas，and to explore the influence of coal moisture content change on the antireflection effect under cyclic microwave conditions，firstly，the transverse relaxation time (T₂) spectrum and longitudinal relaxation time (T₁) -T₂ spectrum characterizing the pore structure characteristics of coal samples were obtained by NMR technology. Then，the characteristic parameters of nuclear magnetic resonance were obtained by using T₂ data，and the change of pore structure evolution with water content under cyclic microwave radiation was further clarified. Finally，based on the mechanism of cyclic microwave permeability enhancement，the pore structure evolution mechanism of different water-bearing coal bodies was revealed. The results show that the pore structure of coal with different water saturation is obviously improved under cyclic microwave radiation，and the coal sample with 75% water saturation has a better antireflection effect than other test coal samples. In the process of cyclic microwave radiation promoting the evolution of pores to larger pores，pore blockage occurs due to the thermal fracture of coal，and increasing water saturation can reduce this phenomenon. The cyclic microwave anti-reflection mainly relies on thermal stress and air pressure. With the improvement of coal permeability，the effect of microwave anti-reflection is weakened，and the influence of coal water content is weakened.

Physical evidence investigation was a necessary means and important link to identify the causes of hazardous chemical incidents. However，the manifestations of hazardous chemical incidents were often explosions and fires，which could easily trigger a domino effect，making physical evidence investigation somewhat difficult. In order to improve the efficiency of on-site inspections and reduce the occurrence of hazardous chemical incidents. MFA method was adopted to conduct on-site intelligence information analysis and explore the application value of MFA theoretical methods in the physical evidence inspection of hazardous chemical incidents based on specific cases. Based on "Jiangsu Xiangshui 3·21 serious Explosion Accident"，"Material Flow Analysis Map" and "Hazardous Substance Distribution Map" were drawn for Tianjiayi Chemical Plant，and material flow analysis research was conducted on the involved enterprises. The results indicate that MFA can identify hazardous areas and substances，providing safety protection reference information for on-site inspectors. It can also provide scope and direction for extracting，inspecting，and identifying on-site physical evidence.

In order to ensure the normal operation of the low-background experimental chamber and prevent structural collapse，a structural safety analysis was conducted using Abaqus software. Initially，a simplified model of the experimental chamber was established based on the finite element method. This was followed by static load response analysis under extreme conditions，seismic load response simulations，and buckling analyses. Finally，the stress response and buckling critical loads of the oxygen-free copper sections with varying thicknesses were calculated to determine the permissible limit wall thickness of the experimental chamber. The results indicated that，under static pressure，the weakest regions of the chamber were the top of the oxygen-free copper section and the transition area of the circular end cap，with a critical buckling load of 0.307 MPa and a permissible limit wall thickness of 5.1 mm.

To improve the evacuation efficiency and ensure the safety of passengers on an open deck in the event of an accident，a heterogeneous evacuation model considering passenger heterogeneity and group effect was constructed using AnyLogic software. Four simulated evacuation scenarios，including individuals，two-person，three-person and mixed groups，were constructed，and the evacuation process of heterogeneous passengers under different group sizes was simulated. The results indicate that with the increase of the group size，the total evacuation time increases nonlinearly. Specifically，the evacuation time for passengers in two-person，three-person and mixed-group scenarios is 11.8%，19.6% and 15.5% longer than that in individual evacuations，respectively. Additionally，the peak of passengers' arrival at the terminal occurs in the early and middle stages of evacuation. In group evacuations，the higher expected passenger speed correlates with more dispersed arrival time distributions. These findings highlight the interaction effect between heterogeneous passengers and group effect in the evacuation process.

In order to improve the safety of the shale oil gathering and transportation process，this paper took the shale oil gathering and transportation process under the in-situ transformation technology of superheated steam injection of oil shale as the evaluation object. In the process of shale oil gathering and transportation，the hazard were analyzed and the whole process was divided into three subsystems. The risk of each subsystem was analyzed qualitatively by using hazard and operability analysis(HAZOP) method. According to the results of the qualitative analysis，the probability of fire and explosion accidents and the risk grade of each subsystem were calculated by using layer of protection analysis(LOPA) and Dow fire and explosion index(F&EI) method. The nodes of shale oil gathering and transportation process were divided，and Bow-tie models for oil and gas leakage accidents containing hydrogen sulfide and oil and gas leakage accidents after purification were established respectively. Based on results of risk assessment，effective safety prevention and control measures were developed. The results show that the subsystems that may cause accidents in the oil and gas gathering and transportation process are: steam generation system，cooling separation system，ammonia desulfurization system and cooling separation system，in which the leakage of the steam generation system will not cause fire and explosion accidents，and the fire and explosion risk grades of the remaining subsystems are: ammonia desulfurization system，cooling separation system and gas extraction and desulfurization system in order from heavy to light.

To improve the efficiency of disaster reconnaissance，a prioritized multi-UAV cooperative scheduling optimization model was proposed for the UAV reconnaissance scheduling problem in disaster emergency responses. An improved tabu search algorithm was proposed by using a mixed integer nonlinear programming model. Moreover，specific neighborhood operators and repair operators were used to enhance the algorithm's search capability and solution quality. Two cases were designed to validate the model and algorithm performance. The first case was based on the actual scenario of the Zhengzhou flood in 2021，and the second case simulated examples of different scales. The results indicated that the model and algorithm were effectively validated. The effects of flight speed，UAV quantity，model，and endurance on reconnaissance capabilities were investigated through sensitivity analyses. The reconnaissance efficiency can be significantly improved by increasing the number of UAV models and optimizing them. UAVs with strong reconnaissance capabilities should be given priority when resources are limited. However，flight speed is more critical when resources are sufficient.