Abstract:To address the challenge of measuring coal seam gas pressure in water-bearing surrounding rock under fracture water interference,this study analyzes the equilibrium relationship between gas and water pres-sure in water-bearing coal-rock layers.It reveals that for vertical boreholes,the pressure measurement tube should first drain water before venting gas,while for inclined boreholes,gas venting precedes water drainage.Based on fluid statics principles and integrated with innovative sealing technology and pressure measurement devices,the system achieves automatic gas-water separation in the pressure measurement chamber.Through field measurements,theoretical calculations,and result comparisons,the study accurately determines coal seam gas pressure.The paper proposes a "three-seal three-injection" segmented pressurized grouting sealing process combined with gas-water separation devices in pressure measurement chambers,enabling automatic gas -water separation and cyclic water drainage.Field measurements and theoretical analysis at the Sun Tuan Coal Mine's 10th coal seam roof and floor multi-layer sandstone aquifer successfully measured real coal seam gas pressure(0.32-0.46 MPa),effectively resolving measurement distortion caused by water pressure interference in traditional methods.This provides a reliable technical approach for accurate gas pressure determination in water-rich coal seams.

Abstract:Inadequate assessment of the sealing environment,and inappropriate sealing techniques and material parameters,lead to low gas pressure measurement value,high failure rates,increased costs and poor sealing quality in gas pressure measurement boreholes.By analyzing the distribution patterns of mining-induced influ-ence radius of roadway surrounding rock under different coal-rock conditions,scientific requirements for the layout of gas pressure measurement boreholes are proposed.Based on the characteristics of coal-rock fractures between the borehole opening location and the pressure measurement chamber,pressure measurement boreholes are divided into four major types:complete type,separation type,in-seam type,and cross-seam type.Corre-sponding borehole sealing methods are proposed.Combined with field applications,the results of gas pressure measurements under different sealing conditions were analyzed,providing reliable engineering guidance for ac-curately determining gas pressure in underground coal seams.

Abstract:To address the challenging issue of safe mining under rock burst prevention in working faces influ-enced by deep coal pillars,a systematic study and practice were conducted on the mechanism and preventive measures of rock burst failure.This was achieved through a combined methodology of theoretical analysis,nu-merical simulation,and engineering validation.The results indicate that:(1)Based on the "three-zone load-ing" theory,the estimated thickness of the immediate loading zone is 24 m,while that of the delayed loading zone is 51m.The maximum stress during the initial mining stage of the working face is 46.6 MPa,with a stress concentration factor of approximately 1.8.(2)Numerical simulation shows that the maximum stress in the coal pillar is about 45.4 MPa,which aligns with theoretical estimations.(3)Combining theoretical estimation and numerical simulation,it was determined that the working face is subjected to high stress during the initial min-ing period,resulting in a significant risk of rock burst.Targeted prevention measures combining drilling and blasting were proposed for rock burst control.The effectiveness was verified using micro seismic monitoring da-ta.After implementation,the frequency of micro seismic events decreased by 87.7％compared to the pre-con-struction phase,and the total energy of these events decreased by 83.4％.The energy accumulated in the 13.2 m thick siltstone roof of the coal seam was effectively released,achieving satisfactory pressure relief results and ensuring the safe mining of the working face.

Abstract:Aiming at the dual disaster threats of impact ground pressure and roof slab water damage in Zhaox-ian Coal Mine,it is proposed to adopt segmental fracturing of horizontal wells on the ground for disaster preven-tion and control.According to the key layer theory and the expansion mechanism of water-conducting fracture zone,40～50 m composite sandstone layer above the coal seam is identified as the target fracturing layer,and 32 fracturing segments are arranged to implement fracturing weakening to the target layer.Concurrently,joint fracturing monitoring is conducted by placing micro-seismic sensors above and below the wells to capture mi-croseismic signals during the fracturing period.Additionally,pressure sensors and flow meters are installed at the wellheads to monitor the pumping and injecting pressures throughout the fracturing process The changes in pumping pressure,flow rate,displacement and other parameters during the fracturing process are recorded,along with the water outflow from each section of the well during the fracturing period.The results show that by incorporating atemporary plugging agent,each fractured section undergo 3 to 4 cycles of repeated fracturing.Large energy microseismic events typically occur during the formation fracturing and fracture extension stages.Throughout the fracturing construction period,there is a significant increase in both the frequency and energy of microseismic events,with events exceeding 103 J accounting for 83.17％of the total energy.Based on the geo-metrical pattern of fracture spatial expansion derived from the projection of microseismic events,the average length of fractures 32 fractured sections reached 317m,while the average fracture height was 46.8m,meeting the design requirements in both horizontal and vertical.dimensions.The percentages of 5.1％,30.8％,and 32.9％can serve as reference points for determining the timing and quantity of the temporary plugging agent to be added.In comparison to the unfractured workface,after fracturing,the mineral pressure during the initial mining and"square"period remained stable,and both the height of the water-conducting fissure zone and the fracture-mining ratio exhibited a decreasing trend.This indicates that the implementation of horizontal well fracturing has effectively achieved the anticipated standards for mitigating impact ground pressure and control-ling water damage from the top plate of the layer.

Abstract:This paper systematically investigates the profound connections between intrinsic dimension theory in high-dimensional spacetime and the Kakeya conjecture.By comparative analysis of their dimensional defi-nitions,mathematical frameworks,and physical implications,we reveal the inherent consistency between fractal geometric structures and high-dimensional physical models in preserving information integrity.The resolution of the three-dimensional Kakeya conjecture by Wang Hong's team not only addresses a century-old mathemat-ical challenge but also provides novel mathematical tools for string theory compactification schemes,demonstra-ting the coexistence of dimensional reduction and directional information preservation.Our findings indicate that the intrinsic dimension of high-dimensional spacetime can be unified through dynamic equilibrium of Kak-eya-type structures,achieving local expression of physical laws while maintaining global consistency.This work opens new avenues for quantum gravity theory research.

Abstract:To address issues such as the scarcity of text data and data distortion,this paper takes Deep Seek as an example,uses netizens'comments as experimental samples,and employs sentiment analysis as verifica-tion methods.It focuses on the application of AI tools in text data enhancement and explores its technical im-plementation,advantages,and challenges.Through experimental verification,the emotion value distribution of the enhanced sample data after data augmentation is similar to that of the original sample,still remaining between-10 and 10 points.The proportion of positive emotion data to negative emotion data still roughly re-mains at 4:6.In the environment where the main body of the text data center remains unchanged,the senti-ment words as subordinate relationships have been expanded,the network relationship of the original text has been enhanced,and the diversity of the text data has been increased.Through experimental verification and other methods,the effects that data augmentation approaches based on AI tools can achieve in AGI develop-ment are demonstrated,and the AI tools and interaction interface methods are analyzed to facilitate subsequent AGI developers in conducting relevant code conversions and provide valuable references for researchers in re-lated fields.

Abstract:Aiming at the shortcomings of the traditional inductor-capacitor-inductor(LCL)filtering method for grid-connected inverters,such as poor grid current quality,weak dynamic performance,and low disturbance re-jection capability,a reduced-order sliding-mode linear active disturbance rejection control(SM-LADRC)strategy is proposed.This method simplifies the parameter tuning process by employing a reduced-order linear extended state observer(LESO)to accurately estimate and compensate for both internal and external disturb-ances within the system.Meanwhile,the sliding mode control theory is integrated to formulate a sliding-mode state error feedback control law,taking advantage of its rapid convergence characteristics to enhance the dy-namic response capability of the system.Simulation results demonstrate that,in comparison to traditional linear active disturbance rejection control(LADRC),the proposed strategy significantly reduces the total harmonic distortion(THD)of the grid current to below 0.64%,shortens the dynamic response time to 0.008 seconds,and decreases the current deviation by 47%.Moreover,it maintains high robustness under complex operating conditions such as grid voltage fluctuations and harmonic injection.Therefore,the reduced-order SM-LADRC strategy effectively enhances the system's disturbance rejection capability and grid current quality,lowers system costs,and exhibits excellent dynamic performance.This approach provides a novel solution for the con-trol of LCL-type grid-connected inverters.

Abstract:To accurately predict the development height of the water-conducting fracture zone in super-thick coal seam of Zhaoxian Coal Mine,this paper controls the variation of single influencing factor parameters through numerical simulation,and quantitatively analyzes the correlation between the thickness of coal seam mining,the length of working face,the buried depth of coal seam and the development height of water-conduc-ting fracture zone.Combined with the existing research results,the influence of mining method and overburden type on the development height of water flowing fractured zone is qualitatively expounded.By systematically organizing field observation data from multiple mines in Huanglong Jurassic coalfield,two prediction models for the development height of the water-conducting fracture zone,suitable for the thick coal seam of Zhaoxian coal mine,are constructed:a multivariate nonlinear fitting model and a BP neural network prediction model.Based on the above analysis results of influencing factors and measured data,the fitting training and verification of the observation data of water-conducting fracture zones in multiple mines in Huanglong coalfield are conducted.The average relative error of the multivariate nonlinear fitting formula is 7.43%,and the overall correlation co-efficient R of the BP neural network prediction model is 0.96.The mining parameters of the 1303 and 2306 working faces in the Zhaoxian Coal Mine were selected for prediction and application.The results indicate that both prediction methods demonstrate high accuracy;specifically,the average relative error between the predic-tions generated by the BP neural network model and the measured site values is smaller,indicating superior prediction accuracy.The two prediction methods proposed in this paper are user-friendly and exhibit strong generalization capabilities,providing a reliable reference for the prevention and control of roof separation water disasters in fully mechanized caving mines within the Jurassic coalfield of Huanglong and similar regions.

Abstract:To clarify the evolutionary trajectory and development trends of smart emergency research in China,this study conducts a bibliometric and visualization analysis based on the CNKI database using CiteSpace and VOSviewer.The results indicate that:(1)the overall number of publications on smart emergency has been in-creasing,roughly experiencing three stages:"technological germination-system construction-integrated deepe-ning";(2)research hotspots are mainly concentrated in emerging technology-driven fields such as the Internet of Things,big data,and artificial intelligence;(3)research institutions are predominantly universities,but the author cooperation network is relatively sparse,with insufficient cross-institutional and cross-team collabora-tion.Based on these findings,this paper proposes several development suggestions,including promoting the standardization of terminology systems,enhancing information infrastructure,deepening the application of intel-ligent technologies,and establishing a multi-actor collaborative governance system.These results aim to provide a reference for the theoretical improvement and practical application of China's smart emergency gov-ernance system.

Abstract:When major public health emergencies occur,the efficient distribution of various emergency supplies plays a crucial role in curbing the development of the epidemic and ensuring people's lives.This article ad-dresses the challenges of location selection and vehicle distribution path planning for emergency logistics cen-ters,proposing an optimization method that considers capacity constraints.In selecting a logistics center loca-tion,the K-means method weighted by demand,is employed to cluster demand points,ensuring that high-de-mand points are situated closer to the logistics center.This approach reduces logistics costs and enhances dis-tribution efficiency.A Double Q-learning reinforcement learning algorithm,which accounts for capacity limita-tions,is introduced for planning distribution paths.This algorithm mitigates the issue of Q value overestimation through a dual Q network structure and constructs a reward function.Under the condition of limited vehicles load capacity,the algorithm takes into account the alignment between the quantity of on-board materials and the demand at each demand point,while simultaneously minimizing the total transportation distances from the logistics center to all demand points.The experimental section includes four scenarios with 20,30,40,and 50 demand points.Results indicate that,compared to traditional heuristic algorithms,the total driving distance of this algorithm across the four scenarios was reduced by an average of approximately 4.8%,while the computa-tion time was shortened by an average of about 94%.Consequently,the delivery efficiency of the emergency logistics system was significantly improved.

Abstract:To reduce the hazards of safety accidents in prefabricated building construction,improve the safety management level of prefabricated building construction,study and analyze the influencing factors of safety management in the prefabricated building construction process,and construct a safety risk assessment model for prefabricated building construction.Firstly,based on engineering practice and litera-ture research,the safety risk index is determined through the Analytic Hierarchy Process to objectively re-flect the importance of risk elements.Secondly,based on the matter-element theory,the multi-level ex-tension evaluation method calculates the correlation degree and risk level of the secondary evaluation indi-cators and the primary evaluation indicators respectively,and finally determines the safety level to which the overall target layer belongs.Through the evaluation of a certain prefabricated building project in Hefei,the results show that the construction safety evaluation grade of this prefabricated building project is level II,which is highly consistent with the actual safety management effect of the project,verifying the sci-entificity and applicability of the model.

Abstract:Artificial intelligence technology(AI),as a new engine to promote enterprise development,is in-creasingly becoming an indispensable core element of modern enterprises.This paper focuses on coal enterpri-ses and utilizes panel data from A-share listed companies in China's coal industry spanning from 2007 to 2022 to explore the influence mechanism of AI technology on the production efficiency of these enterprises.The em-pirical study shows that the application of AI technology not only promotes the popularization of intelligent equipment and significantly enhances the production rates,but also improves the overall production efficiency of coal enterprises by reinforcing safety and security systems.Further mediation effect tests reveal that AI tech-nology can indirectly enhance production efficiency through the mediation path of bolstering enterprise innova-tion capabilities.Based on the conclusions of the study,it is recommended that government departments increase policy support for AI technology,and enterprises should augment their R&D investments in the AI field to fully leverage the benefits of AI technology on enhancing production efficiency.

Abstract:This studyproposesa solution based on cement stabilization technology to address the issueof coal gangue resource utilisation in the Huaixi Lake coal mining subsidence area.Through systematic optimization of material proportions and mechanical property testing,the road performance characteristics of gangue mixtures were elucidated.The results show that the 7d unconfined compressive strength(4.29～5.60 MPa)and split tensile strength(0.42～0.58 MPa)of all proportioning schemes meet the required standards.Among these,the M7 group exhibits the optimal compressive performance(5.60 MPa),while the M5 group demonstrates the best tensile characteristics(0.77 MPa).Engineering verification reveals that the average value of 14d uncon-fined compressive strength of the mixture with the M5 proportion(5%cement and 40%gangue)reaches 5.31 MPa,thereby fully satisfying the strength standardsfor grass-roots materials in secondary roads.Microstructural analysis indicates that the material possesses a dense interfacial transition zone and an optimized pore structure,contributing to its excellent plastic deformation capacity and durability.

Abstract:The deformation and instability of argillaceous cemented surrounding rock restrict the safe and effi-cient mining of coal mines.This paper takes Xiaoyun Coal Mine as the research object.Through methods such as indoor experiments,X-ray diffraction,numerical simulation and classification evaluation,the structural characteristics and hydrodynamic variation attributes of argillaceous cemented rocks are revealed.The research results show that through X-ray diffraction analysis,it is found that the clay mineral content of the argillaceous cemented rock is relatively high,mainly consisting of kaolinite,illite/mongolite mixed layer and illite,which have significant expansibility and softening characteristics upon contact with water.Numerical simulation shows that an increase in clay mineral content will reduce the strong cementation between clastic particles and in-crease the weak cementation between clay particles,thereby weakening the mechanical properties of the rock mass.Under immersion conditions,the disintegration process of argillaceous cemented rocks is divided into three stages:rapid argillization,fracture propagation and complete disintegration.The expansion stress increa-ses exponentially with the immersion time,but the mechanical properties gradually decline.Based on the AHP classification evaluation,the degree of hydration of argilified cemented rocks is classified into primitive un-hydrated,moderately hydrated and strongly hydrated according to the comprehensive index Qy of hydration de-gree.The research conclusion provides a theoretical basis for the support design and disaster prevention and control of argillaceous cemented rocks.

Abstract:To assess the risk level of hazardous chemicals in hydrogen production stations,the CASST-QRA quantitative risk assessment method was adopted to simulate and analyze the accident consequences of hydrogen buffer tanks,hydrogen storage tanks and compressed hydrogen pipelines under the condition of mid-hole leakage,and to evaluate the acceptability of their personal risks and social risks.The results show that in the cloud explosion disaster mode,the accident consequences of compressed hydrogen pipeline leakage are the most serious,while in the flash fire mode,the influence range of hydrogen storage tank leakage is the largest,and its death radius can reach 1.07 to 9.14 times that of the cloud explosion mode.In addition,both personal risks and social risks meet the requirements of the risk benchmark.The research results can provide a theoreti-cal basis for the safety design and risk control of key equipment in hydrogen production stations.

Abstract:The pumping pillar is a key equipment for ensuring safe mining through empty tunnels,and its slurry composition and load-bearing performance directly affect the support effect.This paper takes the 12127 working face of Liuta Coal Mine as the background and studies the influence of slurry ratio and height-to-diameter ratio on the strength of pumping pillars through compressive strength tests.The results show that the pumping pillars also exhibit significant size effects,and their axial pressure failure characteristics are consistent with those of prefabricated pillars.The stability of the roadway pillars was compared and analyzed in combination with FLAC software,and topology optimization was carried out with the help of Ameba software.A conical pillar structure was obtained,that is,a columnwith a small upper top surface and a large lower top surface.As for the filling walls,the support design can be optimized in the form of small mountain peaks.The pumping pillar support effect in the empty alley is good,effectively controlling the deformation of the surrounding rock of the working face.Relevant mechanical property tests and optimization design methods can be provided for reference.

Abstract:As urbanization progresses and population density escalates,subways have become a critical infra-structure in modern cities.However,the complex spatial structure exacerbates safety hazards during evacuation.Based on actual subway surveys of subway stations,a model was constructed using Anylogic simu-lation software.Through literature research,parameters were established to design daily behavior logic for pe-destrians entering,transferring,and exiting the station.This approach not only simulates interactions within the station but also constructs emergency evacuation logic.The developed evacuation model collects pedestrian movement data,quantifies the ＂danger coefficient＂ of pedestrians,and categorizes their safety status.A Cat-Boost classification model is employed to predict and evaluate pedestrian safety levels.The research findings provide relevant data support for optimizing subway station facility layouts and formulating emergency response plans,which are crucial for improving evacuation efficiency and reducing safety risks.

Abstract:Aiming at the problems of insufficient recognition accuracy and generalization degree of coal mine gas and coal dust explosion sounds,a recognition method for coal mine gas and coal dust explosion sounds based on VGG and CNN is proposed.Deploy mine microphones in key monitoring areas of coal mines to cap-ture the operation of coal mine equipment and environmental sounds in real time.Use the VGGish network to process the collected audio signals,extract the sound spectra as sound representations,and then input them into CNN to construct sound recognition models for gas and coal dust explosions.For the sound signal to be tested,the spectrogram is also extracted and input into the trained model for classification.The effectiveness of this method was verified through experiments.Firstly,spectral graph extraction and analysis were carried out on the sounds of gas explosion,coal dust explosion,coal mining machine operation,roadheader operation and ventilator operation,verifying the effectiveness and reliability of the spectral graph extraction method.The spectrogram comparison experiment shows that this spectrogram provides more accurate and richer acoustic fea-tures,increases the discrimination between explosive and non-explosive sounds,and facilitates model training.The experimental results show that the average recognition rate of the algorithm proposed in this paper is 97.87%,the accuracy rate is 94.26%,and the recall rate is 100%,which is significantly better than the existing literature methods,verifying the effectiveness and robustness of the algorithm.The time-consuming test results show that the average training time is 46.4 s,the average recognition time is 1.175 s,and the total average duration is 47.55 s.This algorithm maintains a short processing time under different training set ratios,indicating that the proposed algorithm has excellent recognition efficiency.

Abstract:The roadway of the 2201 working face of Yingpanhao Coal Mine has a large burial depth,a large cross-section and weak coal seams on the sides.Under the existing support conditions,the deformation of the side is large and the support strength is insufficient.Based on the geological conditions of the working face and the original support method,the support scheme was optimized,and the stability of the roadway during the tunneling process was analyzed by numerical simulation.The on-site monitoring research shows that after adopting the support optimization scheme,the maximum approach of the two sides is 276mm,which is 76.6%less than the original support section.Meanwhile,within the support range,no roof delamination occurred,indicating the effectiveness and rationality of the support optimization scheme in controlling the weak coal side roadways of Yingpanhao Coal Mine.

Abstract:To study the influence of working face air volume on the distribution of the spontaneous combustion"three zones"in the goaf,the critical oxygen concentration of these zones was determined based on the charac-teristics of the low-temperature oxidation process of coal.Using the 823 working face of Yuandian No.1 Coal Mine as the research object,the range of the spontaneous combustion"three zones"in the goaf was measuredon-site.To explore the effect of the changes in air volume at the mining face on these zones,the dis-tribution characteristics of the spontaneous combustion'three zones'in the goaf under varying air volumes and plugging measures were simulated after constructing a model with COMSOL software,considering air leakage in the goaf.The results indicate that as the air volume at the working face increases,the distribution range of the oxidation zone in the goaf extends deeper,the width of the oxidation zone increases,,and a critical air volume of 1734 m3/min is identified.When the air volume exceeds this critical threshold,the width of the oxidation zone in the goaf increases more significantly.Following the implementation of plugging measures,the distribu-tion range of the oxidation zone in the goaf is notably reduced.As the length of the plugging retaining wall in-creases,the width of the oxidation zone in the goaf decreases.Considering practical site conditions,the length of the plugging retaining wall is set at 20 m.