In order to clarify the connotation and governance path of metaverse safety & security and further enrich the theory of metaverse safety & security，the concept of metaverse safety & security was put forward based on a large safety & security pattern，and the basic features of metaverse safety & security were analyzed. Moreover，the governance path of metaverse safety & security was proposed. The results show that metaverse safety & security refers to the state or ability of the metaverse to reshape spatial and temporal stability，social civilization advancement and human well-being enhancement from the influence of unfavorable factors，and it has eight basic characteristics，namely，relativity，complexity，vibration，extensiveness，immediacy，relevance，publicity，and multidimensionality. Metaverse safety & security governance should integrate the development and safety & security of the metaverse，adhere to the principle of joint consultation and sharing，build a "technology-rule-society" trinity of governance models，and strive to enhance the digital safety & security capacity of the metaverse.

To mitigate the long-term impact of horizontal loads (such as wind，waves and currents) on offshore wind turbines，a finite element model for the ultimate bearing capacity of heterogeneous clay single-pile foundations was developed using ABAQUS software. Temperature was employed as a virtual variable to reflect the relationship between shear strength of heterogeneous soil and depth. The Model Change technique was employed to achieve geostatic equilibrium，and the obtained results regarding the variation in horizontal loads on single-pile foundations were compared with centrifuge test outcomes to validate accuracy. Combining the failure modes of soil under horizontal ultimate loads for both rigid and rigid-flexible piles，the influence of parameters such as aspect ratio，soil elastic modulus coefficient and pile-soil friction coefficient on the horizontal ultimate bearing capacity of single pile foundations was analyzed. The findings indicate that with an increase in pile embedment depth，the pile transitions from a rigid state to a rigid-flexible state，and the soil failure mode shifts from wedge and rotational failure to wedge，full-flow and rotational failure. The soil elastic modulus coefficient has a minor impact on the horizontal ultimate bearing capacity of single-pile foundations，while the aspect ratio and pile-soil friction coefficient exert a significant influence.

In order to explore the mechanism of the influence of work underload on the risk perception ability of coal mine monitoring inspectors，boredom proneness and mind wandering were introduced as mediating variables to construct a chain mediation model of the four. A structured questionnaire was made with four scales: work underload，boredom proneness，mind wandering and risk perception. Quantitative studies were conducted on questionnaire samples from 263 coal mine monitoring inspectors，and the sample data were analyzed using Pearson correlation analysis and mediation effect tests. The results show that work underload has a direct negative effect on the risk perception ability of coal mine monitoring inspectors. Furthermore，work underload also affects risk perception through the independent mediating effects of boredom proneness and mind wandering，and the chain mediating effect of boredom proneness and mind wandering. Therefore，timely detection and intervention of work underload，boredom proneness and mind wandering of inspectors can effectively improve their risk perception ability and prevent accidents.

The double prevention mechanism was a widely used risk control system in hazardous chemical fields in China. However，the theoretical framework at underlying and operational levels was missing. Especially，there was a lack of RCA results to guide double prevention. Therefore，VPSB model was proposed by integrating primary-secondary barrier theory and ECF analysis technology. Furthermore，ECF as a typical RCA method represented the causal of a catastrophic event composed of specific primary-secondary barrier failure modes，providing a visualized diagram for the VPSB model. The model was used to identify hazards and RCA for a typical accident scenario in the Texas explosion of British Petroleum(BP) company. Moreover，the failure modes of double prevention related to management measures were investigated. The comparisons of investigation results between the U.S. Chemical Safety Board (CSB) and BP indicated that people's unsafe actions were taken as the direct cause to carry out in-depth cause analysis. Moreover，the focus was human management，and the failure of the safety supervisors and irregular operations of the operators were macroscopically summarized as the root causes. However，the VPSB model focused on near-miss and the process of major accident hazards，and detailed sub-barrier failure modes were used to highlight the fundamental problems of management systems. Specifically，mechanical integrity management had the largest number of problems because management measures were not conducted as required. This study can provide rectification directions and operability recommendations for enterprises to optimize the relevant work content of the double prevention mechanism.

In order to effectively prevent and control fire accidents of hazardous chemical tanks during transportation，it is necessary to identify the type of tank fire quickly and correctly. The statistical data of domestic hazardous chemicals tanker fire accidents from 2013 to 2020 was analyzed with Python software. According to the characteristics of fire accidents，a regression model with multiple logistic regression theory was established. The three common fire types of hazardous chemicals tankers，namely，jet fire，pool fire and BLEVE(Boiled Liquid Evaporate Vapor Explosion)fire，were regarded as the categories of explained variables. Through the analysis of accident data，a total of 15 fire factors in five aspects，namely，space and road characteristics，time and meteorological characteristics，personnel factors，vehicle and equipment factors，and hazardous chemicals factors，were determined. A multiple logistic regression equation of fire probability of hazardous chemicals tankers was constructed，and the explicitness and accuracy of the equation were tested. The determined model was proved by examples. The probability of three types of fire in hazardous chemicals tankers was obtained. The accident prevention measures were proposed. The results show that it is the most likely a pool fire for a liquefied natural gas tanker，with a probability of 0.55. The second one is jet fire，and the last one is the boiling liquid expanding vapor explosion fire. To reduce the probability of pool fires，measures such as improving the mechanical strength of the container and reducing the collision strength could be adopted to prevent leakage holes of large size in the container. Measures such as slowing down the leakage rate，controlling the leakage range and efficient scientific fire extinguishing are adopted to decrease sequences of tank fire.

Pool fire caused by fuel leakage seriously threatens engine operation and aircraft safety. To deeply understand the complicated physical mechanisms of pool fire in engine fan cavities，temperature variation characteristics of double fuel pool fire were investigated. Firstly，the physical and numerical models of the CFM56-7B engine fan cavity were established based on the software FDS. Secondly，simulated temperature variations of single fuel pool fire were validated against measurements of the Trent 800 engine fan cavity，and then grid independence was analyzed. Finally，the fire development process and temperature variation characteristics of double fuel pools were analyzed within the fan cavity using several detectors and slices. The results indicated two phases for temperature variation of the double fuel-pool fire in the engine cavity，including an increment state and a quasi-steady state. Moreover，temperature variation magnitude was affected by distances between the detectors and the fuel pools. Fuel-pool fire flame propagation inclined to the left side of the fan cavity，causing an increment of fire temperature on the left side. Plume floating，flame fusion，fusion expansion，and full flame coalescences were observed in the axial direction of the cavity.

In order to discover fire accidents in chemical industrial parks in time and reduce accident losses，this study used CNN to establish a real-time fire detection system for chemical industrial parks. Based on CNN，the YOLOv5 algorithm was used to calculate chemical industrial park fire data sets and ordinary fire data sets. The loss value，recall rate，precision and mean average precision of the two data sets were compared. Among them，the loss value and recall rate of the chemical industrial park fire data set are slightly lower，but the precision and mean average precision were higher than that of an ordinary fire data set，which shows the feasibility of detecting fire. In addition，based on fire detection results，this study further designed the flame image recognition software system for the chemical industry park with the help of the PyQt5 program framework，realized the application of fire image and video recognition in the chemical park，and expanded the application scope of the method. The results show that the YOLOv5 target detection algorithm based on convolutional neural network can detect fires in chemical industrial parks in real-time. This detection method is portable，and the results are reliable，which can help improving the safety management level of the chemical industrial park.

In order to explore the similarities and differences，advantages and disadvantages between the definition of cause factors in LCM and the 24Model，a review of the definition of causes and results at various levels for both models was conducted. The definition content and its guidance role in safety practices，focusing on accident causation analysis，were compared. An empirical analysis was conducted using a coal mine gas explosion accident as an example to identify differences in the analysis results between the two models. The research shows that LCM is the first one-dimensional event sequence model that incorporates management factors into accident causation analysis. It provides clear definitions of cause factors at various levels and their logical relationships. However，LCM has issues with overlapping and repetitive definitions of causal factors and fails to reveal deeper accident cause factors such as guiding principles for safety work. 24Model，as a systematic accident causation model，predominantly defines various factors in terms of the organization. It describes the concepts of events，accidents，and safety，categorizing individual safety acts，safety capabilities，and organizational safety management systems，providing meanings and explanations. It explores organizational safety culture and reflects it with 32 elements. Both models' accident causation analysis methods are built on the definitions of cause factors at different levels and are applicable to their respective theoretical frameworks.

In order to explore the contagion mechanism and effect of unsafe behavior information in groups of construction workers，a theoretical model of the contagion mechanism of unsafe behavior information among construction workers was constructed based on social information processing theory，theory of planned behavior，and social contagion theory. In this model，information about workmates' unsafe behaviors was served as the independent variable，and behavioral cognitive factors (i.e. behavioral attitudes，subjective norms，and perceived behavioral control) and unsafe behavioral intentions were served as mediating variables. Through developing measurement scales and creating questionnaires to collect data，the theoretical model was empirically tested based on 271 valid samples using the analysis methods of confirmatory factor analysis and structural equation modeling. The results show that workmates' intentional unsafe behaviors and workmates' unsafe communication behaviors can induce new unsafe behaviors through six contagious pathways. Moreover，as a source of contagion，the contagion effect of workmates' intentional unsafe behaviors is greater than that of workmates' unsafe communication behaviors. Managers can effectively control the contagion effect of unsafe behavior information among construction workers by controlling contagion information sources and weakening infectious media.

In order to recognize the explosion suppression ability of potassium-containing fine water mist in the scenario of gas leakage in urban comprehensive pipeline corridors，the explosion suppression tests were carried out with additive-containing fine water mist located outside the methane-air explosion area by a self-made explosion experimental system. The effects of pure water and fine water mist of three potassium compounds，namely potassium oxalate，potassium carbonate and potassium chloride，on the overpressure and overfire range of 9.5% methane-air explosion were analyzed. The results indicate that the critical explosion suppression atomization concentration range of pure water mist outside the methane-air premixed area is 320-480g/m³. The overpressure decrease rate under potassium oxalate-containing conditions showed a trend of NormalCDF (Normal Cumulative Distribution Function) with increasing mass concentration，and the optimum suppression concentration is 10%. When the atomization concentration is 480 g/m ³，D₃₂ is 61.7 μm，the mass concentration of the compound is 10%，and the explosion suppression ability of water mist containing additives is greater than that of pure water mist. Among them，potassium oxalate has the strongest explosion suppression ability，followed by potassium carbonate and potassium chloride. The peak overpressure reduction rate is 2.32 times，1.88 times，and 1.53 times higher than that under pure water mist conditions，respectively. The range of overfire is reduced by 46.7%，40%，and 13.3%，respectively. Compared to potassium carbonate and potassium chloride，the potassium oxalate fine water mist outside the premixed area could absorb more heat and consume more active free radicals.