In order to swiftly elucidate the influence of internal parameters on the fracturing performance of a liquid CO₂ fracturing tool and optimize its functionality for enhanced coal seam gas extraction efficiency，a rapid assessment experimental apparatus was designed. A set of 9 orthogonal experiments involving 4 horizontal and 3 influencing factors was conducted utilizing a 38 mm mining-specific fracturing tool. The study analyzed the relative significance of the internal charge quantity in the heating tube，liquid CO₂ filling volume in the main pipe，the thickness of the fracture plate，and the caliber of the release aperture on the fracturing tool's performance. Furthermore，pivotal influencing factors were subjected to fixed-variable experiments to explore their impact patterns on the fracturing performance of the liquid CO₂ fracturing tool. Results indicate that，for the 38 mm mining-specific CO₂ fracturing tool，the thickness of the fracture plate exerts the most substantial influence on the fracturing tool's performance，followed by the internal charge quantity in the heating tube. The impact of the liquid CO₂ filling volume in the main pipe and the caliber of the release aperture is comparatively weaker. The fracturing performance of the liquid CO₂ fracturing tool gradually stabilizes with an increase in the thickness of the fracture plate，reaching a point where the plate does not rupture. When the internal parameters of the 38 mm fracturing tool are set to a CO₂ mass of 0.33 kg，a release caliber of 18 mm，a charge quantity of 60 g，and a fracture plate thickness of 2.0 mm，the tool's fracturing performance corresponds to a TNT(Trinitrotoluene) equivalent of 0.202 kg which is enhanced by 21.9 % compared to the current on-site parameters.

In order to solve the problem of travelling obstacle detection in the context of complex open pit mines，a mining road obstacle detection algorithm based on improved cross-scale feature fusion is proposed. Firstly，to address the problem of unbalanced small target sample categories in the original mine dataset，a data enhancement method based on geometric transformation and weighted Poisson fusion is used to expand the number of samples.Secondly，a cross-stage connectivity network that is more suitable for obstacle detection is proposed in the feature extraction stage to increase the detection scale and improve the algorithm's learning ability of the small target features，and then a 3D parameterless attention (SimAM) and de-weighted Bi-directional feature fusion pyramid network (Bi-FPN) are proposed in the feature fusion stage to improve the multi-scale detection performance by enlarging the predicted feature map and feature receptive field. Finally，to address the problems of sample imbalance and imprecise obstacle bounding box localisation in the training，the quality focal loss function (QFL) and the scalable Intersection and combination ratio loss function (SIoU)，which combines the classification score with the quality prediction of the position to improve the localisation accuracy for dense occlusion targets. The results show that the improved method can effectively identify unstructured road obstacles in open pit mining area under complex background，and in practical application，the detection accuracy reaches 91.88% and the detection speed reaches 68.7 f/s，which has a better performance of small-target and multi-scale detection compared with the mainstream detection methods，and it can satisfy the requirements of obstacle safety detection in the travelling of unmanned mine cards in open pit mining area.

In order to develop the measurement of hydrogen sulfide content in coal seams towards informatization，intelligence，and automation，it is necessary to innovate the measurement equipment and technical methods. By analyzing the adsorption characteristics of H₂S in coal seams，the achievements in the development and application of hydrogen sulfide determination devices in recent years were summarized from the aspects of the convenience and accuracy of the construction of hydrogen sulfide determination devices. The current research status of methods for measuring hydrogen sulfide content in coal seams both domestically and internationally was elaborate. Finally，in view of the limitations of the equipment and methods for measuring hydrogen sulfide in coal seams，the future development direction of coal seam hydrogen sulfide measurement technology was discussed，and a technical system for improving the calculation error of coal seam hydrogen sulfide loss was proposed. An integrated coal sample underground crushing and desorption system，an automated desorption gas metering system，an intelligent monitoring and automated data analysis and processing system are constructed. The results show that the coal mine underground sampling method with internal and external double drill pipes，the loss of hydrogen sulfide during drilling and sampling is compensated. The measuring device is equipped with underground direct crushing equipment，filters，negative pressure vacuum tanks，and sensors for direct underground gas extraction and analysis，improving the accuracy of measuring hydrogen sulfide content in coal seams.

In order to address the severe consequences of lithium battery vehicle fires during ship transportation，a vehicle fire simulation model of a ro-ro ship deck lithium battery was constructed. Firstly，the accuracy of the fire simulation model of single and dual lithium battery vehicles was verified by using the full-scale fire experiment data of lithium battery vehicles. Then，the verified simulation model was applied to simulate the fire of a lithium battery vehicle on the deck of a ro-ro ship，and the variation rules of fire heat release rate，temperature and radiant heat under different vehicle spacing were analyzed. The results show that in the initial stage of the lithium battery vehicle fire，the flame first spreads to the side-parked vehicles，especially the side of the vehicle affected by the jet fire，and then expands to the front and rear vehicles. The front vehicle suffers significantly more fire damage than the rear vehicle. At the same time，jet fire aggravates the spread and development of lithium battery vehicle fires. The temperature of the area with jet fire is significantly higher than that of the area without jet fire，and the adjacent vehicles affected by jet fire are ignited first. The numerical simulation method can effectively simulate the fire development and spreading process of the vehicle carrying lithium battery on a ship.

To achieve the accurate evaluation of steel structure fire resistance in the converter station，based on the possible standard，power and hydrocarbon fire scenarios，the thermal insulation mechanism of ultra-thin fireproof coating as well as its thermal insulation performance on steel members with different steel materials and different cross-section shape factors were investigated through micro-scale thermogravimetric-Fourier transform infrared (TG-FTIR) spectroscopy experiments and small-scale fire test furnace heat insulation experiments. The experimental results show that the faster the fire heating rate，the higher the peak mass loss rate and the higher the peak temperature of the fireproof coating. Different fire heating curves have no effect on the type of gases escaping from the thermal decomposition of fireproof coatings，but have an effect on the amount and peak temperature of escaping gases. Compared with the power and hydrocarbon fire，in the condition of standard fire，more gases are produced before 750 ℃，resulting in better expansion and heat insulation. Furthermore，the fire resistance of the ultra-thin fireproof coatings on the carbon steel and stainless steel at various cross-section shape factors at power and hydrocarbon fire is worse than that of standard fire，indicating poor heat insulation abilities.

In order to effectively reduce the risk of blind zones and lack of control in dust environment monitoring，optimize the node coverage control of the dust environment monitoring system in thermal power plants，and prolong the lifetime of WSN，an energy-saving optimization method based on improved genetic algorithms was proposed. Firstly，based on node coverage，total energy consumption of node deployment and total energy consumption of node communication and transmission，the network coverage quality objective function was constructed. Then，aiming at the problems of the local optimization and coding duplication existing in traditional genetic algorithms，the chromosome combination scheme of integer coding，the adaptive adjustment method of crossover and mutation probability and the elite retention strategy were proposed. Finally，the simulation comparison and analysis were performed to determine the optimized node number and distribution scheme. The results show that the improved genetic algorithm significantly improves the convergence speed. The number of iterations required is reduced to 20，and the fitness value is optimized by 52.18%. In the node deployment and coverage study，the optimized number of nodes is 42，the coverage rate is 97.28%，and the node dormancy rate is 76.19%，which effectively improves the energy-saving effect of the dust environmental monitoring system in the thermal power plant.

In order to evaluate the consequences of H₂S-containing associated gas leakage on the platform，ANSYS Fluent software was used to simulate the spatiotemporal changes of the gas diffusion. According to the development process of H₂S-containing gas diffusion，the toxic area of the associated gas cloud in two scenarios，namely no protective measures and emergency protective measures，were compared. A quantitative evaluation of the degree of toxic risk of H₂S-containing associated gas leakage was conducted by using the dose-response model. The results showed that compared to the scenario with no protective measures，after taking the “shutdown” measure，the volume and horizontal diffusion distance of the gas cloud with H₂S concentration ranging from 500-2 000 mg/m³ are reduced by 20%-37.5% and 15.4%-47.6%，respectively. After that，the toxic gas cloud volume and horizontal diffusion distance can be further reduced rapidly by taking the "blowdown" measures. By considering the H₂S accumulative concentration and exposure reaction，“shutdown + blowdown” measures can obviously reduce the fatality probability. The fatality of three monitoring spots near the leakage hole decreases from 0.998，0.034 and 0.000 239 to 0.759，0.002 9 and 0.000 000 65 respectively. The area of intolerable section and ALARP section of horizontal plane on the middle deck decrease by 63.7% and 81.7% after taking the emergency protective measures. The hazardous degree of toxic consequences caused by associated gas leakage can be significantly reduced.

A two-dimensional diffusion model was developed using the computational fluid dynamics software Fluent across various longitudinal wind speeds to examine the impact of longitudinal ventilation in underground tunnels on the dispersion of thermal runaway gases from lithium-ion batteries. The findings demonstrate that the diffusion of thermal runaway gas on the upwind side of the gas inlet is restricted by longitudinal ventilation，while it is enhanced on the downwind side. At a wind speed of 3 m/s，the time it takes for thermal runaway gas to diffuse to the exit boundary in about 40% that when there is no wind. Moreover，increasing wind speed within the computational domain results in a larger diffusion area under the same diffusion time. The expansion of the explosion area generally exhibits an increasing-then-decreasing trend as diffusion time advances. In the wind speed range of 0.25-3 m/s，the maximum explosion area grows proportionally with wind speed，forming an exponential relationship. Notably，the maximum hazardous area reaches a minimum of 6.79 m² at a wind speed of 0.75 m/s. Considering the maximum explosion range，wind speeds between 0.5 and 0.75 m/s appear optimal for diluting and diffusing thermal runaway gas in the tunnel.

A comprehensive and sophisticated multi-algorithm coupled dynamic prediction model is proposed to address the intricate reality and stringent accuracy requirements of predicting tailings dam displacement. Firstly，by employing a time series decomposition model，the cumulative displacement is disaggregated into its trend and cyclical components. The trend term displacement is then forecasted using a Gaussian regression time series prediction model. Secondly，various Copula functions are employed to investigate the overall correlation between the inducing factors and the cyclical term displacement. Owing to the diverse influencing factors and strong nonlinearities associated with the cyclical term displacement，the MISSA-CNN-BiLSTM model is utilized for prediction. Lastly，the predicted trend term displacement from the Gaussian regression model and the predicted cyclical term displacement from the MISSA-CNN-BiLSTM model are merged. The results demonstrate a high degree of consistency between the predicted cumulative landslide displacements and the measured values，with a correlation coefficient of 0.996 and a root mean square error (RMSE) of 0.13 mm. The multi-algorithm coupled model，based on MISSA-CNN-BiLSTM，exhibits remarkable prediction accuracy and effectively captures step changes in tailings dam displacements.

In order to explore the damage characteristics of coal under different ultrasonic excitation time，the ultrasonic excitation test system，nuclear magnetic resonance imaging system，stereo microscope and automatic permeability test system of coal core were used to analyze the changes of pore structure，surface crack and permeability characteristics of coal under different ultrasonic excitation time. The results show that with the increase of ultrasonic excitation time，the change rates of T2 spectral peak area，total porosity，surface fracture area and permeability of small，medium and large pores in coal are linearly increased. When the coal body is excited by ultrasonic for 30 to 150 min，the change rate of T2 peak area of micro，medium and large pores increase from 14.60%，52.50% and 24.90% to 61.30%，145.50% and 235.70%，respectively. The total porosity change rate，surface crack area change rate and permeability change rate increased from 5.04 %，47.27 % and 41.67 % to 24.93 %，127.91 % and 208.33 %，respectively. Under the excitation of different ultrasonic time，the change rate of permeability of the coal and the change rate of total porosity and the change rate of surface cracking area are in line with the linear increasing relationship，with the increase of ultrasonic excitation time，the pore and crack modification effect of coal is enhanced，and the permeability can be improved.