In order to ensure the safety and reliability of the structural connection of assembled bridges, the strength test design of different types of interface agents was carried out based on bridge engineering and structural mechanics, and the mechanical properties of different cement grades, water-cement ratio and ash-sand ratio were analyzed. The change law of the strength of cement mortar in the early stage is faster than that in the later stage. The change law of the compressive strength of different types of interface agents with different ages was obtained, the prediction model of the relationship between different ages and strength of cement mortar was constructed, and the optimal mechanical properties of SS-III were proposed from the perspective of the bending-compression ratio. The relationship between different interface agents and the tensile strength of adhesion splitting was tested and analyzed by developing the test device of adhesion splitting tensile strength. The bonding performance of SS-III was determined to be the best interface bonding agent for assembled bridges from the perspective of the bending ratio and bonding properties. cement mortar as the interface agent for assembled bridges is more reasonable, which provides a new research idea for the safety and reliability analysis of the interface connection of assembled bridges.

In order to solve the problem that the tunnel crosses the water-rich fault fracture zone, the construction risk is large, and the problems of surrounding rock instability and water inrush are very likely to occur. Based on the engineering background of the Xiaocaoba tunnel of the Chongqing-Kunming high-speed railway crossing the water-rich fault fracture zone, the fluid-structure interaction numerical model was established by using FLAC^3D to study whether to consider the influence of groundwater action, different grouting forms, grouting ring thickness and the force of the supporting structure under the influence of groundwater. The results show that the stability of the surrounding rock is poor under the consideration of groundwater, and after the tunnel excavation, the groundwater is distributed in a “funnel-shaped” manner around the tunnel after the seepage reaches a steady state, and the stability of the surrounding rock is enhanced after the advanced grouting reinforcement, and the grouting reinforcement form of the whole perimeter is better than that of the grouting around the arch wall. On the basis of selecting the grouting form, the parameters of the grouting ring were continuously optimized, and it was concluded that with the increase of the ratio of grouting ring thickness and permeability coefficient, it can effectively reduce the displacement of surrounding rock, limit the development of plastic zone, and reduce the pore water pressure of the primary branch, and the increase of the thickness of the grouting ring can significantly change the distribution range of the pore water pressure of the primary branch. After the construction of the appropriate grouting scheme on site, the feasibility of the grouting scheme and the rationality of the selection of grouting parameters were verified by comparing the monitoring values around the tunnel with the simulated values, and the stability of the surrounding rock was effectively controlled. The research results can provide reference value for the design and construction of similar tunnel projects in the future.

To study the influence of dense floor openings on existing main structures of subway stations, based on the reconstruction and expansion project of Dongsi Shitiao Station on Line 3 of Beijing Subway, finite element analysis method was used to simulate the dense openings on the bottom plate and the construction of vertical shafts. The stress and deformation characteristics of the station main structure were analyzed, and the impact of different phased opening schemes on the structural deformation of the station floor was discussed. Finally, verification was conducted in conjunction with on-site monitoring. The results show as follows. During the excavation and support process of shafts after floor opening, staggered excavation of adjacent shafts can effectively reduce the deformation of the station main structure, with the deformation being related to the depths of the two shafts and the distance between them. When the number of floor openings is large and dense, the opening order needs to be reasonably allocated. Through comparison and optimization of different phased opening schemes, it is found that compared to the three-phase opening scheme, the two-phase opening scheme increases the settlement by an average of 0.3 mm. However, the former shortens the construction period, improves construction efficiency, and is therefore recommended under the condition of meeting deformation control requirements.

Traffic accidents pose significant risks to public safety and represent a critical issue in transportation systems. The accurate prediction of accident severity is essential for implementing effective prevention and intervention measures. An ensemble learning approach, combining the advanced algorithms XGBoost and MLP, was proposed to enhance the accuracy of traffic accident severity predictions. A stacked classifier was established and its performance in traffic accident prediction was thoroughly evaluated. The experimental results demonstrate that the integrated model significantly improves prediction accuracy compared to the traditional XGBoost model, with a notable 20.41% increase in the macro-average F₁ score. The advantages and innovations of the model, including model integration and network transformation, were highlighted. Additionally, the key features affecting the prediction results were analyzed, and the model's potential value in practical applications was explored. This study provides more scientific and efficient decision support for traffic safety management and is expected to play a crucial role in fields such as traffic management and intelligent driving.

The precision of temperature field control in the hypersonic wind tunnel directly affects the accuracy of wind tunnel test data. In view of the control problems of hypersonic wind tunnel temperature field control, such as large delay, nonlinear and multi-variable coupling, phase space reconstruction of data affecting temperature was carried out and support vector regression was applied to the hypersonic wind tunnel temperature field predictive control to improve the accuracy and efficiency of hypersonic wind tunnel temperature field control. At the same time, considering that the selection of kernel function in support vector regression machine and the optimization of kernel function parameters affect the accuracy of prediction results, the support vector machine model was established based on different kernel functions, and the optimal kernel function was selected through comparative verification and analysis, and the corresponding PSR-SVR model was established to predict the temperature field of the hypersonic wind tunnel, so as to improve the temperature prediction accuracy. The analysis of actual temperature field data shows the effectiveness of the proposed method.

Unique test requirements in civil large aircraft flight testing, characterized by short task durations, wide measurement point distribution, and numerous measurement locations, are addressed. Challenges in the existing wired Ethernet-based onboard data acquisition systems, including difficult measurement equipment installation, complex test cable layout, and prolonged retrofitting periods, are identified. A flexible, miniaturized, and compact space-compatible measurement system for critical wing structural state parameter measurements during civil aircraft flight testing was proposed. An integrated microsystem, including a flexible antenna module and a multi-sensor parameter collection module, was developed and integrated into the civil aircraft wing. The system's reliability and stable signal transmission were demonstrated. The design and application of a wireless flexible measurement system for wing state monitoring on civil aircraft were detailed. The system design approach, data transmission strategy, and integration with third-party loggers were described. Ground and flight tests were conducted to collect data.The onboard flexible system's capability to measure temperature, three-axis vibration, and pressure is verified.

Antibiotics are new pollutants in water environment, which have potential threat to aquatic ecological environment and human health. Considering that sulfanilamide antibiotics are difficult to degrade and oxidize and cannot be effectively removed by sewage treatment plants, Fe₇₈Si₉B₁₃/H₂O₂ system was constructed to efficiently and environmentally degrade sulfanilamide antibiotic pollution. Fe₇₈Si₉B₁₃/H₂O₂ system was selected as the best process for efficient degradation of SDZ(sulfadiazine) through a series of experiments with different experimental parameters. The experimental results show that 250 μg/L SDZ can be degraded 100% within 4 min at pH=2, H₂O₂=50 μmol/L and temperature 25 ℃, and its apparent rate constant (K_obs) can reach 0.99 min^-1. The activation energy of SDZ removal in the system is 25.42 kJ/mol. The quenching agent experiments show that the key active substance of Fe₇₈Si₉B₁₃/H₂O₂ system degrades SDZ is hydroxyl radical (·OH). Through high resolution identification of intermediates and toxicity assessment of the intermediates, the results show that all intermediates are substantially reduced or harmless compared to the mother. In addition, the practical application potential of the oxidation degradation system is verified through the actual water degradation experiment.

The resilience theory has been introduced into the aviation logistics supply chain to enhance its ability to withstand internal and external shocks and uncertainty. A resilience evaluation model for the aviation logistics supply chain based on a Bayesian network was proposed. The Bayesian network structure index was established from the macro performance layer, the middle influence layer, and the bottom cause layer. Subsequently, the Bayesian network model was constructed, and the probability inference process of the Bayesian network nodes was completed using the Markov Chain Monte Carlo algorithm. This enabled the acquisition of the probability distribution of aviation logistics supply chain resilience through parameter learning and model inference. Furthermore, the Bayesian network model was employed for reverse reasoning, sensitivity analysis, and cause chain analysis to identify the key variables and sensitive factors affecting the resilience of the aviation supply chain. Based on these analyses, suggestions for improving resilience were put forward. Research findings indicate that the resilience value of China's aviation logistics supply chain is approximately 53%, signifying a high level of resilience. The Bayesian network model has proven effective in quantifying the resilience value of the aviation logistics supply chain, as well as in reasoning and analyzing the influence of each factor on resilience value, thus contributing to the enhancement of the risk resistance ability of the aviation logistics supply chain.

The utilization of offshore floating photovoltaic has became a hotspot in major coastal countries in complex marine environment. Offshore floating photovoltaic is currently in the phase of the experimental and pilot test. In order to explore the main components and current technological status of offshore floating photovoltaic technology, and to assist in the large-scale and commercial development of offshore floating photovoltaic in China, by sorting out the main components of offshore floating photovoltaic, based on the research and application status of offshore floating photovoltaic at home and abroad, focusing on the structural types of floating platforms, and analyzing the characteristics of various types of floating platforms. The results reveal that the maturity level of zero-gap and non-zero-gap floating platform concepts is not high, and the novel body materials should be considered to reduce engineering costs. The electrical equipment that is suitable for the complex marine environment needs to be further improved. The business modes of integrating floating solar power with other marine scenarios should be actively developed. The strategy, security, and means of operation and maintenance need to be given special attention. The research aims to provide the current status and challenges of key technologies, and offer reference experience and research directions for the development and design of offshore floating photovoltaic.

The occurrence characteristics and genetic models of geothermal resources is an important basis for the development of geothermal resources. Drilling data, geophysical and geochemical data was applied to analyze the thermal reservoir, cap rock, heat sources, channels and supply elements, and the genetic model of geothermal system in the southwest of Zhoukou Depression was established. The development prospect was also evaluated. The geothermal resources in study area can be divided into sedimentation basin type with low temperature. Mantle derived heat is the main heat source, and the geothermal flow in the north part is higher than that in the south part, also in the protruding area is higher than that in the depressed area, reaching over 70 mW/m². The average geothermal gradient is about 2.8 ℃/hm, dominated by heat conduction system. Isotope analysis shows that the supply source comes from atmospheric precipitation in the western low mountains and hills, which infiltrates through the exposed area and moves along permeable strata and unconformity towards the east, and is heated and warmed up. The pores of the Neogene and Paleogene sandstones, as well as the karst pores of the Cambrian-Ordovician carbonate rocks, are the main storage spaces for fluids. The silt and clay deposits developed in the upper part of the Quaternary and Neogene systems form a good waterproof and thermal insulation cover layer. The development and utilization risk of the Neogene system is the lowest, with a floor depth of 400~1 400 m, increasing towards the north. The average sand to soil ratio is 40.9%, with a water flow between 40~60 m³/h and a wellhead temperature of 43~48 ℃. The development of faults also promotes the upwelling of deep heat flow, and there is a local thermal convection warming effect. Finally, four favorable development area for porous geothermal resources and three favorable areas for karst resources were identified.