Gas drainage can prevent accidents such as coal and gas outbursts and gas explosions, which is of great significance for coal mine safety production. The level of permeability directly determines the effect of gas drainage. Therefore, experts and scholars in related fields have conducted extensive research with regard to adopting different measures to increase the permeability of coal and thereby improve the efficiency of gas drainage. However, in analyzing, comparing, and summarizing the advantages, disadvantages, and adaptability of various methods, there are few review studies in the literature. First, this Review investigates the principles, processes, and effects of different methods and finds that each method has its own specific application conditions and limitations. Simultaneously, it classifies different stimulation methods according to the principle of stimulation, which are mainly divided into physical stimulation methods, chemical stimulation methods, microbial stimulation methods, and thermal stimulation methods. Then, for better field applications, this Review investigates emphatically these methods that are currently popular but still in the laboratory stage, such as acidification stimulation and freeze–thaw stimulation, and analyzes the experimental methods, principles, experimental effects, influencing factors, etc. Permeability represents the flow capacity of gas in porous media and thereby affects the efficiency of gas extraction. Therefore, this Review summarizes the influencing factor of permeability. Finally, this Review discusses the aspect that needs to be perfected and improved for different methods and points out the problems and possible development directions in the future.

The establishment of an emergency management system has obvious complexity, and the establishment of an enterprise’s emergency management system is influenced by external factors such as assessment agencies and regulatory departments as well as by the internal influence of various factors within the enterprise itself, such as profits and personnel quality. In order to study the impact of different factors on the construction of emergency management systems of enterprises under the current regulatory environment and under the existing reward-penalty mechanism, this study introduces factors such as rent-seeking behavior and economic level to build an evolutionary game model composed of enterprises, third-party safety assessment agencies, and government regulators. Based on the official statistics published in China and the field evidence of enterprises, third-party agencies, and emergency management departments in Nanjing, Jiangsu Province, China. The evolution path of the game system and the influence of the reward-penalty mechanism, rent-seeking behavior, and economic level on the strategy evolution process of the game model were analyzed by numerical simulation. The results show that there is a mechanism of mutual promotion in the strategy evolution of the game subjects, and the strategy choice of each subject shows the following characteristics: (1) reasonable subsidies and penalties play a positive role in promoting the construction of emergency management systems by enterprises. (2) Increasing the rent-seeking costs of enterprises and the reputational impact of regulators can promote the positive evolution of enterprises’ and regulators’ strategies. (3) Reducing the cost of the establishment can help enterprises establish emergency management systems, but it will reduce the probability of strict supervision by the regulators. Therefore, the government should develop a reasonable reward-penalty mechanism to replace fixed payments to enterprises and third-party agencies with tax reductions. In addition, local governments should establish an information and consultation mechanism and make the system construction and evaluation process public.

As one of the important energy industries, the safe production of coal mines not only concerns the safety of employees, but also affects the sustainable development of society. Recent rescue cases have shown that the layout of material bases and the allocation of emergency materials need to be further optimized. For this problem, this paper adopts the material hierarchical reserve mode for the first time, combining the material hierarchical reserve mode, multi-level material base selection model, and fuzzy analytic hierarchy process (FAHP) method to determine the optimal location of the coal mine material base in Liaoning Province. Determine the reserve level of emergency materials through evaluation and clustering analysis of various emergency materials. Improve the traditional gravity model and construct a multi-objective planning model for multi-level material base site selection. Apply the reserve level of emergency materials and real regional data to the site selection model, and use genetic algorithm (GA) to solve the model. Then, the optimal site selection scheme was selected using FAHP, and sensitivity analysis was conducted. The research results indicate that: (1) 9 county-level, 6 city-level and 2 provincial-level material bases will be constructed. (2) The location selection of material bases is not only affected by costs, but also by the density of road networks. (3) The use of hierarchical material reserve mode can significantly reduce the construction cost of material bases. Compared to the traditional material reserve mode, it can reduce costs by 86.6%. Compared to a single-level material bases, it can still reduce costs by 74.7%. The research results of this paper can be used for the selection of emergency material bases and the allocation of emergency material reserves, which can reduce costs and promote the improvement of regional emergency rescue capabilities.

By decomposing the coal mine emergency rescue organization and coal mine emergency rescue work, the synergy entropy function is constructed by combining the synergy class with the entropy theory, and the synergy efficiency assessment model of coal mine emergency rescue is established. Analyze the synergistic relationship between departments in the rescue organization and between departments and functional units, construct the synergistic influence matrix, and obtain the synergistic status of the coal mine emergency rescue system by calculating the synergistic entropy, synergistic efficiency and synergistic degree. The quantitative analysis of the emergency rescue system in coal mines is achieved by analyzing the situation of the rescue work in coal mines and evaluating the rescue organizations at each tier based on the established evaluation model.