To address the issues of allocation of emergency rescuers，emergency rescue equipment，and disaster locations in the early stage of emergency rescue under the background of large-scale geological disasters，as well as improve the efficiency and quality of emergency rescue，an emergency rescue allocation decision-making method was proposed based on the three-sided matching theory. Firstly，the selection process among the three parties of emergency rescue was presented as a three-sided matching issue. Then，the multi-attribute preference evaluation information of the matching three parties was standardized，and a multi-attribute comprehensive preference score matrix was proposed. Furthermore，a three-sided matching stable and satisfactory model in the early stage of emergency rescue was developed to maximize system stability and total preference utility. Finally，the performance and accuracy of the proposed model were validated against cases. The results indicated that the proposed model reached reasonable matching between rescuers，emergency rescue equipment，and disaster locations in emergency rescue scenarios due to considering the effects of various parties' preferences on resource allocation. Furthermore，it can contribute to reducing the deployment time of emergency rescue operations and improve emergency efficiency and quality.

In order to clarify inerting effect of liquid nitrogen on the thermal runaway explosion of a 280Ah energy storage lithium battery，based on experiment analysis of composition and explosion limit of battery thermal runaway gas，FLACS was used to simulate explosion overpressure of battery thermal runaway gas in a storage container. Standard experiments and real experiments were carried out to analyze inerting effect of liquid nitrogen on battery thermal runaway gas. Results show that thermal runaway gas explosion overpressure increases gradually with an increase of its volume. Ignition of more than 1.1 m³ of thermal runaway gas can cause serious consequences. A single 280 Ah lithium iron phosphate battery in 100% charged state，heating in a vacuum state，heating in a vacuum state can trigger thermal runaway of the battery and produce 134.6 L of thermal runaway gas with CO₂，H₂，CO，CH₄ and C₂H₄ as the main components. Thermal runaway gas is a flammable gas，and explosion limit range is between 8.5% and 45.5%. N₂ can effectively inert thermal runaway gas and significantly reduce the explosion limit range of thermal runaway gas. Limiting N₂ volume fraction is 84.7%. Spray 69 kg liquid nitrogen into a 35 m³ energy storage container to inert battery thermal runaway gas. When volume fraction of N2 is higher than limiting nitrogen volume fraction，battery thermal runaway gas can be effectively inerted，and effective protection time is 2 200 s.

In order to improve the economic benefits of coal mining enterprises and reasonable arrangement of various safety inputs，a model to solve the correlation between indicators was constructed. Firstly，the influencing factors of economic benefits based on safety investment were analyzed，and a set of scientific and reasonable structural index systems was constructed on this basis. Secondly，the entropy weight method was used to determine the weight of each index. Then，in view of the correlation between indicators，based on the safety input structure，the entropy weight-Choquet fuzzy integral model based on a 2-additive fuzzy measure was introduced to calculate the economic benefit evaluation value. Finally，a coal mine was selected for empirical analysis to verify the feasibility and effectiveness of the constructed model. The results show that the constructed model is more reliable than technique for order preference by similarity to an ideal solution(TOPSIS) method. This model can take into account the mutual influence and correlation between indicators and obtain more accurate and scientific evaluation results.

To deeply explore whether ride-hailing services directly affect road traffic crashes and whether they indirectly affect road traffic crashes by changing the usage of buses and private cars，based on panel data from 114 cities in China from 2005-2017，the multi-period DID method and the causal steps method are used to estimate the impact mechanism of ride-hailing services on road traffic crashes. The results show that the entry of ride-hailing services increases road traffic crashes by 5.6%，and this conclusion still holds after performing robustness tests such as parallel trend and Propensity Score Matching-DID. Ride-hailing services significantly reduce public transit usage by about 19.3%，thus indirectly increasing road traffic crashes by 0.71%，which indicates that public transit usage plays a mediating effect. Ride-hailing services significantly increase private car usage by 5%，thus indirectly increasing road traffic crashes by 0.14%，which indicates that private car usage plays a mediating effect. The decrease in public transit usage is an important reason why ride-hailing services indirectly increase road traffic crashes. Government departments should strengthen the regulation of ride-hailing services，while encouraging the synergistic development of ride-hailing services and public transit.

To improve coalbed methane extraction efficiency in deep mines，a high-flow sealing hole grouting material was developed using superfine cement as the base material to overcome issues of commonly used high polymer sealed materials such as high cost and flammable，low permeability of ordinary cement materials，and insufficient strength of paste materials such as fly ash. The hydration mechanism of the developed high-flow sealing grouting material was explored by an experimental study on the material's mechanical properties，combined with the measurements by scanning electron microscope(SEM)and X-ray diffraction(XRD). The results indicated that a large amount of calcium silicate hydrate (C-S-H) gel and ettringite (AFt) crystals were generated in the high-flow sealing grouting material during the initial phase of hydration. Furthermore，the gel particles of hydration products filled the pores of the material with the hydration reaction. Compared to commonly used cement sealing grouting material，the hydration reaction of the developed material was much faster and more complete，and the overall structure was more denser. Moreover，the compressive strength was increased by 3.68%. Therefore，the developed high-flow sealing hole grouting material can maintain the stability of gas extraction boreholes and improve gas extraction efficiency.

In order to improve the construction of undergraduate curriculum settings in the field of safety engineering，a total of 68 outstanding undergraduate theses (designs) from 38 universities in 2021 were collected and organized in this study. CiteSpace software was used to perform cluster analysis on the keywords of the theses，and the current research topics of undergraduate theses (designs) were clarified. Subsequently，the industry background of safety engineering in the 38 universities was investigated，and the differences of curriculums between representative Chinese and foreign universities in safety-related disciplines were statistically analyzed. The results show that the high-frequency keywords in the 68 theses are mainly related to the following aspects: "numerical simulation"，"disaster warning"，"safety management system" and "resilience". Based on the investigation results of the industry background of universities，among the 68 theses(designs)，the number of theses in the direction of public safety accounts for 45.6%，and the number of papers on mine safety accounts for 8.82%，but nearly 40% of the 38 universities take mine safety as a key service area，which showed that the research directions of safety disciplines theses has shifted from focus on industry safety to "general safety science". However，the characteristic curriculums still primarily focus on industry safety，with some repetition in the content of basic curriculums. Furthermore，there is a lack of numerical simulation curriculums. These factors make it difficult for the currently offered curriculums to support students in conducting their graduation projects. Additionally，compared with safety-related disciplines in foreign universities，it was found that the number of basic curriculums in safety engineering in China is relatively high，whereas the practical curriculums show the opposite condition.

To propose effective safety cognition strategies and reduce safety accident occurrence，it is urgent to investigate the safety cognition evolution process and characteristics of cavern constructors. Firstly，factors affecting safety cognition were identified based on a complex sociotechnical system and the 24Model，then a safety cognition index system of cavern constructors was proposed. Subsequently，the weight coefficient was calculated by the Super Decisions software. Then，system dynamic (SD) theory was used to determine the interrelationship between factors. SD numerical model was developed including organizational safety management and other three subsystems，and a cognitive correction mechanism based on safety investments was applied to the SD numerical model. Finally，numerical simulations and sensitive analysis were performed by the SD model based on actual engineering examples. The results indicated that the overall safety cognition of cavern constructors changed from a downward trend to an upward trend by increasing safety investments and exerting the role of cognitive correction mechanisms with project processes. Organizational safety management has the greatest influence on the safety cognition of carve constructors，which was consistent with the assumption of 24Model. Therefore，the scientific performance of the SD numerical model was validated.

In order to cultivate a good safety culture in the operation stage of the nuclear power plant，the evaluation index system of safety culture in the operation stage of the nuclear power plant was constructed by analyzing the operation characteristics of the nuclear power plant and summarizing the existing evaluation index system and evaluation model，which was divided into four levels: values，behavior，system and environment，and subdivided into 13 secondary indicators and 61 tertiary indicators. On this basis，considering the non-independence and possible mutual influence between indicators，a comprehensive method based on DEMATEL and ANP was proposed to determine the weight of the index system. The results show that this method can get the evaluation index weight of nuclear safety culture by combining the survey data，and identify that the key to improving nuclear safety culture lies in the safety awareness of decision-makers and setting an example，which provides guidance for the cultivation of safety culture in the operation stage of nuclear power plants.

The association between MHO and HUA and whether liver enzyme abnormalities could modify this association were studied. The cross-sectional study was conducted using 6，868 steelworkers in Hebei Iron and Steel Company who participated in occupational medical examinations as the study population. The data were analyzed using logistic regression models and interaction effect model. The results show that，in a multiple adjusted logistic model，the risk of HUA is increased 2.13-fold (odds ratio (OR)=2.13，95% confidence interval (CI): 1.08-4.21) for metabolically healthy generalized obesity (MHGO). The risk of HUA is increased 2.25-fold (OR=2.25，95%CI: 1.14-4.45) for metabolically healthy abdominal obesity (MHAO). In stratified analysis，in the group with elevated liver enzymes，the prevalence of HUA in steelworkers with MHO(MHGO and MHAO) is significantly higher than that in the group with normal liver enzymes，and the interaction between obesity phenotypes and liver enzyme levels has a statistically significant effect on HUA (P<0.05). MHO is associated with a high prevalence of HUA. Liver enzyme levels may alter the relationship between MHO and HUA.

Deep mining faces high temperature and pressure environments. In order to understand the adsorption gas characteristics of deep coal bodies，an isothermal adsorption experiment was conducted to study the coal's adsorption characteristics under different temperature and pressure conditions. The experiment examined both macro and micro perspectives of the coal's adsorption behavior，molecular dynamics isothermal adsorption simulation and theoretical analysis. The research results are as follows. When the gas pressure is low，the difference between the absolute adsorption capacity and the excess adsorption capacity is not significant at different temperatures. When the gas pressure is high，the difference between the absolute adsorption capacity and the excess adsorption capacity increases with the increase in temperature. In the process of gas pressure increasing from 0 to 20 MPa，the amount of gas adsorbed by coal is divided into three stages. The growth pattern consists of a rapid increase during the initial stage，followed by short-term stability in the middle stage，and a gradual decline in the later stage. The equal adsorption heat and adsorption capacity of coal meet the exponential function relationship. The temperature-pressure adsorption model based on the equivalent adsorption heat deduction can predict the quantity of isothermal adsorption gas under any temperature and pressure conditions，and the relative error between the measured and predicted values is 10%.