To enhance hydrogen safety regulation in China, this paper systematically reviewed the development trends of the global hydrogen industry and its safety regulatory frameworks. Based on this, a comparative analysis was conducted from the perspectives of safety supervision institutions, laws and regulations, standard systems, and technological development for hydrogen industry both domestically and internationally. Drawing on international experience and considering China's specific conditions, policy recommendations were proposed in five aspects: clarifying regulatory responsibilities, improving the supply of laws and policies, accelerating the standard system, strengthening technological support, and deepening exchanges and cooperation. The results show that the global hydrogen energy sector has entered a phase of rapid industrialization. Countries with relatively mature hydrogen industries have built safety governance systems characterized by top-level coordination and planning, full-chain coverage regulation, and standard system support. In comparison, China's hydrogen industry still lags behind the demands of its rapid development in terms of the comprehensiveness of safety regulatory system, the coherence of its standard system, and the capacity for key technology support. It is therefore necessary to further clarify the regulatory responsibilities of relevant departments across the full chain of hydrogen production, storage, transportation, refueling, and end-use applications, and to establish and improve cross-departmental collaborative regulatory mechanisms. It is of great importance to accelerate the formulation of systematic hydrogen safety-specific laws and regulations and to build a standard system covering the entire industrial chain, as well as to strengthen R&D on safety technologies and the construction of professional experimental platforms. By doing this, the safety supervision efficiency shall be enhanced comprehensively in China's hydrogen industry.

To enhance China's work safety governance, policy texts related to work safety were analyzed using text analysis and coding methods, aiming to provide an in-depth understanding of the current policy system and to identify existing gaps in China's safety governance policies. Based on Duxiu database and the website of the Central People's Government, 80 policy texts issued between 1949 and 2024 were selected. NVivo 12 plus software was used to conduct coding analysis, which was then employed to summarize the distribution and usage of policy tools in China's work safety governance. The research show that China's work safety governance policies employ a comprehensive set of policy tools. They exhibit a development pattern centered on pre-accident prevention, supported by talents and technology, and complemented by coordinated measures during and after accidents. At the same time, the current policy structure is still unbalanced. Policy tools play a prominent role, while enabling and incentive tools are insufficient. The integration degree of policy tools with governance logic elements is low, affecting the overall effectiveness of governance. In the future, it is necessary to promote the optimization of policy tool structure, balance the distribution of governance elements, and strengthen the deep integration of policies and elements to enhance the level of work safety governance.

To address the problems of low accuracy and insufficient adaptability in existing methods for determining the parameters of PIM for predicting surface deformation prediction in goaf areas under thick unconsolidated layers, 36 sets of measured surface movement data from coal mining working faces were selected. The core indicators of mining-geological conditions were screened via Hierarchical Cluster Analysis (HCA), Entropy Weight Method(EWM) and Grey Relational Degree (GRD) analysis. Furthermore, the GRNN model was optimized by integrating K-fold cross-validation with the neighborhood perturbation strategy of SAA, and an SAA-GRNN optimization model was constructed for PIM parameter determination. A case study was conducted using 45 sets of data from coal mining working faces with thick unconsolidated layers in the Jining area. The results show that: seven mining-geological condition indicators can be classified into three categories, and five core input indicators were identified screening, namely mining thickness M, coal seam dip angle α, mining depth H, strike mining degree D₃/H, and unconsolidated layer thickness h. The maximum root-mean-squared error (RMSE) of SAA-GRNN model is no more than 0.190 4, the maximum mean absolute error (MAE) is controlled within 0.133 9, the maximum mean absolute percentage error (MAPE) is 0.153 6, and the overall coefficient of determination (R²) is generally above 0.8. Under the same conditions, the prediction errors are greatly reduced compared with those obtained using Back Propagation (BP) neural network and the conventional GRNN model.

To manage risk transmission and reduce the probability of construction safety accidents, the evolution process and characteristics of construction safety risk transmission in high-altitude areas were explored. Firstly, based on construction accident reports of hydropower projects in high-altitude areas and the 4M1E theory, a construction safety risk factor system was constructed from five aspects: personnel, machinery and equipment, materials, management, technology, and environment. The Decision-Making Experiment and Assessment Technique (DEMATEL) was used to analyze risk events triggered by risk factors. Then, based on the SFEP theory, a construction safety risk transmission network was established, and the risk transmission probability of each path was calculated through association rules. The SD method was utilized to construct an SD model of the construction safety risk transmission network. Finally, a large hydropower project in Xizang was taken as an example for simulation verification. The results show that the SD model of the construction safety risk transmission network reveals 29 risk transmission paths from 17 edge events, 15 process events, to 5 final events, as well as their evolution trends and sensitivities. Environmental and management risk events are identified as key nodes, and three key transmission paths are identified. Based on this, targeted risk transmission prevention and control measures are proposed, providing a theoretical basis for the management of construction safety risks in hydropower projects in high-altitude areas.

In order to accurately identify risks and effectively prevent accidents in confined space operations, a scenario-based accident evolution model grounded in key elements was developed to conduct quantitative risk analysis. This study addressed confined space operations by systematically organizing their key elements, which encompass physical characteristics, spatiotemporal context, environmental conditions, safety management, and emergency decision-making. The Web Ontology Language (OWL) was employed to standardize the description of these elements and represent the scenarios, thereby enabling a structured and standardized characterization of accident evolution. Drawing upon data from nearly 50 domestic confined space accident cases, as well as current standards and expert knowledge, the study performed state-based description and correlation analysis on critical aspects, including gas detection, ventilation, personal protective equipment, and accident consequences throughout the operational process. A BN structure and probability parameters were established accordingly. An empirical analysis of a confined space poisoning accident was conducted to validate the model. The results show that the systematic identification of critical safety factors contributes to the structured management of accident knowledge. Furthermore, the BN model constructed on this basis enables quantitative risk assessment and scenario deduction. The empirical findings demonstrate that risk-ignorant rescue attempts constitute the primary factor exacerbating outcomes in confined space accidents, particularly when multiple non-professional responders enter without personal protective equipment. Therefore, emergency plans should clearly define rescue procedures, responsibilities, and protection requirements.

In order to improve the efficiency of data fusion in the wireless sensor network (WSN) of a uranium tailings pond, reduce redundant data transmission, and extend network lifespan, an innovative data fusion algorithm was proposed, namely the SAPSO-BP data fusion algorithm based on improved SA and PSO optimized BP neural network. The algorithm integrated the global search capability of the SA algorithm with the efficient optimization mechanism of the PSO algorithm, incorporating dynamic inertia weights and mutation operators to enhance global search ability and avoid local optima. Furthermore, the improved algorithm was used to optimize the weight matrix and threshold parameters of the BP neural network, constructing a high-performance multi-sensor data fusion model, which was applied to radionuclide monitoring in uranium tailings ponds. The results show that the SAPSO-BP algorithm outperforms the compared algorithms in terms of data fusion accuracy, network energy consumption, and network lifespan. Compared with the traditional BP algorithm, it reduces mean relative error(MRE) and root mean square error(RMSE)by up to 40% and 45%, respectively, and improves the goodness of fit to 0.908 3. Additionally, it delays the first node death to approximately 1 180 rounds, extends the overall network lifespan to about 1 500 rounds, and achieves lower node energy consumption and a more balanced energy distribution.

In order to address frequent hazardous gas leaks in large and medium-sized chemical plant areas, this study proposes a leak source localization method based on a multi-strategy improved PSO(MSPSO) algorithm, leveraging the collaborative capabilities of a small number of UAVs. First, considering the physical constraints UAVs face during actual movement, an acceleration control strategy was integrated into PSO algorithm. Simultaneously, the chemical plant area was divided into distinct zones to more accurately simulate the UAVs' flight states during the search process. Second, an upwind search strategy was introduced based on diffusion characteristics of leak sources, utilizing wind direction information to accelerate the search process. Third, to prevent UAVs from getting stuck in pseudo-leak sources, Cauchy mutation perturbations and simulated annealing mechanisms were employed to enhance the UAVs' ability to escape local optima. Finally, a three-dimensional simulation environment for large and medium-sized chemical plant areas was established to compare and analyze the performance of various swarm intelligence algorithms in simulated scenarios. The results indicate that MSPSO exhibits faster convergence and higher localization success rates, with performance better meeting the leakage source localization requirements of large-to-medium-scale chemical plant areas.

To investigate the influence of pick cone angle on coal-rock fragmentation and dust generation characteristics during underground roadheading operations, a multi-scale integrated approach combining experimental tests and discrete element method (DEM) simulations was adopted. Four picks with cone angles of 78, 92, 105 and 118° were selected as research objects. Roadheading cutting tests were conducted to analyze the particle size distribution of generated debris and dust. DEM simulations using the PBM in Particle Flow Code (PFC) software accurately reproduced the entire process of coal-rock fragmentation and dust generation during roadheading. The evolution trends of crack quantity, crack type, number of minimum-sized discrete particles, and ejection velocity were analyzed under two operational modes of the cutting head: penetration and slewing. The results indicate that as the cone angle increases, the coarseness index (CI) of coal wall debris decreases from 728.92 to 696.91, while the dust proportion increases from 0.4% to 0.67%, demonstrating that the degree of coal wall fragmentation and dust generation increases with pick cone angle. The fragmentation index rises and the uniformity index declines, indicating a broader dust particle size distribution and a higher proportion of fine dust particles. Simulation results show that the total number of cracks on the coal wall increases from 22 980 to 27 272, with tensile cracks consistently accounting for over 73% of the total. The number of minimum-sized free particles increases from 371 to 459, and their average initial ejection velocity decreases from 0.250 m/s to 0.221 m/s. In summary, increasing the pick cone angle intensifies dust generation to a certain extent, but helps suppress the dispersion range of dust.

To fundamentally enhance the safety of lithium-ion batteries, phosphorus-based flame retardants were added to the electrolyte, and the effects of different valence states of phosphorus-based flame retardants on safety performance and electrochemical performance were studied. The impact of phosphorus-based flame retardants on the thermal stability of the electrolyte was compared using self-extinguishing time and differential scanning calorimetry. The influence of phosphorus-based flame retardants on the basic properties of the electrolyte was analyzed through linear sweep voltammetry. Further, cyclic voltammetry tests, cycling performance tests, rate capability tests, and electrochemical impedance spectroscopy were conducted to explore the effects of varying volume ratios of phosphorus-based flame retardants on the electrochemical performance of LiFePO₄|Li half-cells. The results show that electrolytes containing 5% trimethyl phosphate (TMP) and trimethyl phosphite (TMPi) exhibit significantly reduced self-extinguishing times, with the former also expanding the electrochemical window of the electrolyte. The LiFePO₄|Li half-cell with 5% TMP demonstrates a smaller potential difference between the oxidation and reduction peaks, reduced battery polarization, and maintains a higher discharge capacity after 300 cycles, with a capacity retention rate of 99.6%. In contrast, the addition of 5% TMPi leads to a decline in discharge capacity. Methyl phosphate flame retardants exhibit weaker molecular activity and less adverse effects compared to methyl phosphite flame retardants. Under the premise of not compromising electrochemical performance, adding 5% trimethyl phosphate is more effective in improving the safety of lithium-ion batteries.

In order to reveal the influence of small perturbations on the failure and re-initiation of normal detonation and quasi-detonation waves, experimental were carried out on acetylene-oxygen mixtures. Firstly, thin metal plates of different lengths were arranged in the explosion chamber to introduce small-scale perturbations. Then, helical springs with wire diameters of 7 and 9 mm were used to construct rough wall surfaces for generating quasi-detonation. Finally, distributed photoelectric probes were employed to record the arrival times of detonation waves, and a high-speed schlieren system was combined to observe the diffraction and re-initiation processes of detonation waves. The research reveals that introducing minor perturbations significantly reduces the critical initiation pressure threshold. Below this critical initial pressure, re-initiation of the detonation wave is impossible, even with perturbations present. Conversely, above this critical pressure, planar detonation waves within the tube consistently transition to spherical detonation waves in all repeated experiments. The re-initiation site for normal detonation in a smooth tube consistently occurs near the thin plate, whereas the re-initiation location for quasi-detonation in a rough tube exhibits randomness. Quantitative analysis demonstrates distinct critical initiation criteria for the two detonation types: for the successful re-initiation of detonation, the ratio of the critical tube diameter to the detonation cell size must be greater than or equal to 13, while the critical threshold for the successful re-initiation of quasi-detonation is reduced to approximately 8 for the ratio of the critical tube diameter to the cell size.