The evaluation of expressway network resilience has been emphasized due to significant global emergencies. Utilizing complex network theory and the resilience triangle model, a dynamic system was developed to assess the comprehensive performance of nodes, incorporating local, global, and social attributes. A method for evaluating the resilience of expressway networks was proposed, consisting of four stages: initial, disruption, recovery, and stabilization. Six disruption and recovery strategies (node degree, eigenvector, betweenness, accessibility, social attributes, and random selection) were applied to analyze the network’s performance using three key indicators: the number of independent paths, network efficiency, and network connectivity. A topological map of the expressway network spanning the provinces of Shanxi, Shandong, Henan, and Hebei were constructed, and the resilience changes under various disruption and recovery strategies were analyzed. The findings indicate that in the initial stage, the expressway network exhibits a relatively high number of independent paths, suggesting robust anti-risk capabilities. During the disruption stage, network efficiency, the number of independent paths, and network connectivity decrease by 94.32%, 98.18%, and 99.63%, respectively, demonstrating the network’s ability to absorb disruptions. In the recovery stage, the accessibility restoration strategy, which results in the smallest resilience triangle area, exhibits the strongest resilience, whereas the random restoration strategy shows the slowest recovery rate, indicating that it should be avoided whenever possible. In the stabilization stage, network efficiency resilience is found to be superior to that of network connectivity and independent path resilience in the expressway network of the four provinces. It is recommended that urban nodes with higher degree values, such as Xinxiang and Puyang, be prioritized for protection to enhance the overall resilience of the expressway network.

Two schemes, hollow shaft and solid shaft were proposed for the cantilever high-speed rotor of a turbofan engine during the structural design stage. Based on the beam element finite element method, rotor dynamic analysis models with hollow shaft and solid shaft were established, and critical speed and vibration mode calculations were carried out. The calculation results show that hollow shaft structure is suitable for the rotor. Then, an analysis was conducted on the sensitivity of the unbalance response of a rotor with a hollow shaft to the unbalance amount at the characteristic position, providing a basis for the selection of balance surfaces in high-speed dynamic balance test. Finally, the dynamic characteristics test of the simulated rotor with hollow shaft within the full speed range and the high-speed dynamic balance test research at the working speed were completed. The rotor smoothly crossed the two orders bending critical speed and safely operated to the working speed, verifying the rationality of the rotor’s hollow shaft structure and dynamic design. Compared with the experimental results, the calculation error of the established finite element model is not more than 4.08%, which well reflects the dynamic characteristics of the rotor. After high-speed dynamic balancing, the deflection of the rotor at the working speed is significantly reduced, not less than 33.33%. The research results provide reference and technical support for the structural, dynamic design, and experimental research of real low-pressure rotors, and has important engineering value.

The identification of aviation accident risk factors through the system-theoretic process analysis(STPA) method is a qualitative analysis process that does not allow for a quantitative assessment of the extent to which each factor contributes to an accident. To address the above problem, a qualitative and quantitative analysis method combining STPA and Bayesian network (BN) was proposed. Taking the JetBlue A320 aircraft flap accident as an example, the control structure model of the flap control system was constructed by STPA method, and the potential unsafe control behaviors and related causal scenarios were analyzed comprehensively. Then, the results of STPA qualitative analysis were transformed into a Bayesian network model that could be quantitatively analyzed, so as to identify the internal interaction logic and the highly influential factors in the accident, and put forward comprehensive safety recommendations. The analysis results show that the main factor leading to the accident is the failure of hydraulic source, while the failure of power transmission unit (PTU) and the leakage of hydraulic line are the main causes of hydraulic source failure, with a critical importance of 0.688 and 0.299, respectively.

In order to solve the safety problems encountered when aircraft land and taxi on runway surfaces with accumulated water, three-dimensional random uneven half-runway surfaces with different flatness grades were established. The distribution of accumulated water in the landing strip under the influence of runway unevenness was used to investigate the accumulated water distribution characteristic matrix. Moreover, a theoretical model for aircraft landing and taxiing on runways with accumulated water was established, and dynamic simulations were carried out using the Simulink tool to analyze the impact of runways on aircraft landing performance under different accumulated water distribution conditions. The results show that compared with “good” (international roughness index, IRI=1), the landing distance of the runway with “poor” (IRI=5) increases by about 29 m, and the landing distance of the runway with “poor” (IRI=1) increases by 3.7% compared with the ideal smooth road. Moreover, the decrease of road smoothness would aggravate the risk of tire water skiing. If the ground speed of the aircraft is increased from 62 m/s to 82 m/s, the landing distance will directly increase by about 520 m, an increase of about 87%. When the rainfall intensity of 1 mm/min increases from 1 mm/min to 3 mm/min, the landing distance increases by 6.5 m and 7.4 m for each increase in rainfall intensity of 1 mm/min. It is concluded that at the uneven position of the pavement, the greater the grounding speed, the greater the speed when reaching the same position, and the greater the reduction of the adhesion coefficient of the position, up to 11.3%. With the increase of rainfall intensity, the adhesion coefficient decreases gradually. When the rainfall intensity reaches 3 mm/min, the adhesion coefficient decreases by about 20% compared with the dry pavement.

With the rapid development of the global aviation industry, airport ground operations management is increasingly challenging. Ensuring safety, improving efficiency, and reducing environmental impacts constitute critical tasks. To address this, a mixed-integer linear programming model incorporating taxiway conflict prevention was developed. This model aimed to minimize taxi time and CO₂ emissions through dynamic optimization with the non-dominated sorting genetic algorithm II (NSGA-II). Implementation was conducted in Python for a major Chinese hub airport, with results compared against the commercial optimizer Gurobi. Computational findings reveal a 17.46% reduction in total taxi time and an 18.35% decrease in CO₂ emissions across 14 aircraft. The NSGA-II solution is found to be within 1.083% of Gurobi’s optimal solution, while a 95.0% faster computation time is achieved. The capability of NSGA-II in handling large-scale multi-objective taxi path optimization problems is demonstrated. Operational efficiency is enhanced, and CO₂ emissions are significantly reduced by the proposed approach.

In order to effectively evaluate and control the operational risks of unmanned aerial vehicle(UAV), based on the summary of various risk factors of UAV ground impact, the possible causes of UAV ground impact were analyzed, corresponding control measures were determined, and a safety barrier model combining risk analysis and control technology was established. It can clearly display the logical relationship between the causes of UAV operation safety, mitigation measures and accident consequences. Bow-tie (BT) model was mapped to Bayesian network (BN), each element of BT model was quantified, and the probability of unsafe events was calculated. The results show that the model can clearly show the risk control process and effectively reduce the operational risk of UAV. It provides an efficient and practical method for the operational risk assessment and control of UAV.

In order to alleviate the collision risk of non-intersecting runways simultaneous operation, it is necessary to apply a control strategy conforming to the operation characteristics. A collision risk assessment model was constructed by using event tree analysis and Monte Carlo method. Based on event tree analysis, the event to be solved was determined. The probability of related events was calculated by Monte Carlo method. By statistical and fitting the collision event data obtained by the experiment, the safety target level was standardized and the control strategy was put forward. Finally, taking the approach of 01L and the departure of 29R on the non-intersection runways of Daxing Airport as an example, the departure shielding window (0.41~7.39 km) was obtained. Using this strategy, the risk of aircraft collision can be controlled at an acceptable level. The proposed computational model of departure shielding window is of general applicability to the formulation of safe operation control strategies for non-intersecting converging runways.

Groundwater plays a pivotal role in the production and sustenance of life. However, the potential geologic risks associated with its exploitation must be acknowledged. Changes in groundwater levels have been shown to precipitate geologic disasters such as landslides, mudslides, and ground subsidence. Therefore, the mastery of groundwater information is of great scientific significance for disaster prevention, mitigation, and the rational use of water resources. The temperature tracing method is recognized as a promising technique with significant applications in preventing and providing early warning of geological hazards, such as landslides and mudslides. Among the many methods available, this technique was noted for its great potential. The recent groundwater exploration methods, theoretical research, and new indoor experimental research methods was focused on. The latest research progress related to the groundwater method of geothermal inversion in the seepage of rivers and dams, landslides, and groundwater exploration was reviewed. Through comparative analysis with the traditional electric method of exploration, current theoretical models and new problems faced by the practice of engineering exploration were analyzed. Future research should focus on multi-field coupling, multi-parameter integration, analysis of groundwater patterns in special soil sites, dynamic monitoring of groundwater for major projects, and early warning and prediction of geological disasters will be focused on. These research directions will provide essential scientific and technical support for the prevention of geological disasters and water resources management.

The velocity measurement of trunk canals and rivers is regarded as an important basis for water resources management and flood prediction. The techniques and methods for trunk canals velocity measurement based on machine vision were analyzed and synthesized. Particular focus was placed on reviewing the principles, technologies, and recent developments of particle image velocimetry, particle tracking velocimetry, space-time image velocimetry, optical flow methods, and deep learning-based flow measurement methods in recent years. Finally, the existing challenges and issues were addressed, and potential future development directions were proposed.

Squeeze film damper (SFD) is a commonly used vibration reduction device in rotating machinery such as aero-engine. With the development of aviation science and technology, many new structures of SFD have been derived and developed. The categories of new structural squeeze film dampers from the aspects of structural characteristics, vibration reduction characteristics, vibration reduction effects, and application situations were summarized. Besides, the current research status of new structural squeeze film dampers in China in recent years were also summarized. The shortcomings of current research on new structural squeeze film dampers were pointed out, and an outlook of proposes directions and prospects for future research on new structural squeeze film dampers was made. Besides,the application prospects of new structural squeeze film dampers were pointed out. The results provides a reference for the application and selection of new squeeze film dampers in the vibration reduction design of rotor systems in rotating machinery such as aero engines.