During the manufacturing and application of fiber-reinforced composites (FRP), issues such as impact damage and fatigue accumulation cause irreversible subtle damage to the internal structure. Acoustic emission (AE) technology, with its high precision and real-time property, has become an important means to monitor the damage evolution and failure mechanisms of FRP. The applications of acoustic emission technology in the damage characterization of FRP in recent years was reviewed. By conducting research on AE technical means such as parameter analysis, waveform analysis, pattern analysis, and deep-learning analysis, the results showed that parameter analysis and waveform analysis could complement each other in terms of signal characteristics during the detection process, achieving a qualitative description of damage behaviors such as the deformation and fracture of composite structures. Methods such as deep-learning analysis provided important theoretical support for the health monitoring and life prediction of fiber-reinforced composites. Overall, acoustic emission technology can monitor and evaluate the composite structures in operation in real-time. It has great development potential for maintaining the health of FRP materials and preventing sudden failures. In the future, it can be further combined with artificial intelligence technology to improve the accuracy and efficiency of damage identification.

Grouting pavements are susceptible to cracking, which can significantly reduce their service life. For this reason, water-borne epoxy resin (WER) was added to the grouting materials to improve the performance of grouting asphalt mixtures. Grouting materials with different levels of WER were prepared and characterised for their flow properties, setting time, mechanical strength and micromorphology. The road performance of the grouting asphalt mixtures was evaluated through wheel tracking test, low-temperature bending test and water immersion Marshall test. The results show that, WER can form a membrane structure on the surface of hydration products, improving the flexibility of grouting materials. However, it also delays the setting time of grouting materials. The addition of WER slightly diminishes the high-temperature performance of grouting asphalt mixtures, but improves the low-temperature cracking resistance and water stability of grouting asphalt mixtures. In particular, 7.5% WER increases the low-temperature destructive strain of grouting asphalt mixtures by 29.2%.

To enhance market acceptance of construction waste recycling products, the impact of awe on consumers’ purchasing willingness investigated was investigated. Using an emotion assessment scale, purchase intention scores, and fNIRS, along with a virtual purchase experimental setup, the effects of awe induced by nature videos on subjects’willingness to purchase construction waste recycling products were examined. Measurements were conducted to separately assess the emotions induced by nature videos, the willingness to purchase construction waste recycling products, and the changes in brain activity during the viewing of nature videos. The results from the emotion assessment scale revealed that nature videos significantly induced awe emotions. The fNIRS data demonstrated deactivation in the brain's default mode network (DMN), associated with self-processing. This suggests that the experience of awe may be linked to reduced self-consciousness. The scoring data indicated that the awe experienced significantly enhanced the subjects' willingness to purchase construction waste recycling household products, however, the subjects' willingness to purchase construction waste recycling materials were not being significantly influenced by awe. Therefore, in construction waste recycling household product marketing, leveraging awe through natural videos can increase the willingness to purchase construction waste recycling household products, subsequently improving its market acceptance.

The transformation of sludge into biochar adsorbents for the removal of tetracycline contaminants in water bodies represents one of the effective approaches for the resource utilization of sludge and enables the realization of the circular economy concept of “treating waste with waste”. Municipal sludge was employed as the raw material, and sludge biochar was fabricated through pyrolysis for the adsorption and removal of tetracycline. The adsorption and removal efficacy of tetracycline was investigated, and the preparation conditions of sludge biochar and adsorption environmental conditions were optimized. Additionally, by combining methods such as scanning electron microscopy, infrared spectroscopy, and BET(Brunauer,Emmett,Teller) specific surface area testing, the structural characteristics of sludge biochar and the underlying mechanism of its adsorption behavior towards tetracycline were explored. The results indicate that the sludge biochar prepared under a pyrolysis temperature of 800 ℃ and a pyrolysis duration of 4 hours exhibits the optimal adsorption performance for tetracycline. The pH value exerts a significant influence on the adsorption effect. In a weakly acidic environment, the adsorption effect of sludge biochar on tetracycline is the most favorable, with a maximum adsorption capacity reaching 45.33 mg/g. Thermodynamic and kinetic analyses demonstrate that the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model can appropriately fit the adsorption process of tetracycline by sludge biochar. The adsorption process is primarily monolayer adsorption, dominated by surface chemical adsorption. In conjunction with the analysis of characterization test results, the chemical adsorption mainly involves processes such as electrostatic attraction, cation exchange, complex precipitation, π-π conjugation, and hydrogen bonding. Simultaneously, the pore structure characteristics of sludge biochar result in the adsorption process of tetracycline also encompassing pore filling and Van der Waals force.

To address the issue of land and capital waste caused by suboptimal site selection and construction models for urban drone landing and takeoff sites, the maximum coverage model is initially used for site selection. However, due to the uneven distribution of demand points and overly simplistic coverage determination criteria, the results show low coverage rates and overly concentrated site selection. To solve this problem, a method based on spatially continuous demand for the maximum coverage model of drone landing and takeoff site selection was proposed, considering factors such as no-fly zones and application scenarios. Demand objects were determined using a regular grid, and candidate sites were identified using the PIPS(polygon intersection point set) method. The feasibility of the improved model was validated through a case study of site selection for urban drone landing and takeoff sites in Binhai New Area, Tianjin. When the number of landing and takeoff sites was fixed at 14, the improved model increased the actual service area coverage rate from 62.03% to 88.61%. The results indicate that this method better meets the practical requirements for drone landing and takeoff site selection, resulting in more evenly distributed and rational site layouts, and significantly enhancing the service coverage rate of the drone landing and takeoff sites.

Under the context of the rapid rise of smart airports, the widespread deployment of autonomous vehicles requires an efficient safety operation system. In order to develop a collision warning method based on collision probability for airport unmanned driving vehicles, using ADS-B data as a foundation, considering the interaction between aircraft and vehicles at taxiway segments and intersections. The collision probability analysis was conducted for these two types of interactive environments. Through the analysis of single-vehicle warning simulation diagrams, different levels of warning thresholds were set. When the collision probability was 0.3≤p(c)≤0.5, the following vehicle entered the secondary warning state, and the vehicle braking acceleration took a value range of 0.5~1.5 m/s². When p(c)＞0.5, the following vehicle entered the primary warning state, and the vehicle braking acceleration took the maximum value of 2 m/s², and carrying out simulation analysis for the same taxiway and intersection according to the set warning threshold, the simulation test showed that the collision warning method based on collision probability could calculate the probability of collisions occurring during vehicle movement on the taxiway, and perform deceleration braking according to the corresponding warning threshold, effectively reducing the possibility of collision accidents. Through Monte Carlo random simulation experiments, the collision probability change diagram under different driving modes at crossroads was obtained, and the effectiveness of the warning algorithm was verified by using hierarchical warnings for simulation analysis. The simulation experiment proved that regardless of the driving mode, the warning algorithm could effectively avoid collision conflicts, further proving that the proposed method had high adaptability. A collision probability-based collision warning method was constructs for airport unmanned driving vehicles, which can effectively avoid the occurrence of airport field collision conflicts. Meanwhile, it can significantly improve the safety of unmanned driving vehicles in the airport environment.

Transonic fan rotor blades will suffer from morphological decay problems such as leading edge erosion in actual operation, and the flow field structure in the tip zone will change and then induce aerodynamic performance degradation. The effects of leading edge erosion on the tip leakage flow of the fan rotor were investigated from constant numerical computation in this paper. The results show that at the stall point of the eroded blade, its isentropic efficiency, total pressure ratio and mass flow rate decrease by 4.3%, 0.43% and 5.63%, respectively, and the leading-edge erosion also causes a decrease in the stabilized operating margin by 0.69%. For the flow in the tip zone, the leading-edge erosion causes an increase in the entropy increase area and intensity in the flow surface of S1 at the tip zone and the flow surface of S3 in the exit region, and the formation of a low Mach Number flow region in different blade heights; the leakage flow structure under the leading edge erosion undergoes malignant changes, the demarcation point of the main leakage flow and the secondary leakage flow is advanced, carrying more fluid for secondary leakage, and the leakage vortex deflection angle of the eroded blade reaches 30° from 15°, hitting the leading edge of the blade directly and causing flow blockage.

Dynamic compaction is one of the effective methods to eliminate collapsibility of loess foundation. In order to study the mechanism of eliminating loess collapsibility by dynamic compaction, particle size test, collapsibility test, scanning electron microscope test and soil-water characteristic curve (SWCC) test were conducted on undistributed loess and compacted loess in Tongchuan City. The above experimental data was used for analyzing the effect of dynamic compaction on the particle size distribution, microstructural and unsaturated characteristic of loess, as well as the relation between these factors and collapsibility. It is shown that the clay content of the loess in Tongchuan area increases significantly under dynamic compaction. It is found that when the clay content is greater than 36.2%, the loess is no longer collapsible. It is observed that dynamic compaction leads to the formation of small and micro pores from collapsed macropores and mesopores. As a consequence, the density of particles increases and the collapsibility decreases. The slope of the SWCC curve desaturation section of compacted loess is greater than that for undistributed loess. This is because clay particles formed under dynamic compaction act as cementation materials, which is considered to increase the strength of cementation on the one hand, and to be filled in the pores on the other hand, increasing the density of loess. Finally, the results show that the SWCC curve fitting parameter a is related to the proportion of micro-pore area and the collapsibility coefficient. The collapsibility of loess can be judged indirectly from the characteristics of the SWCC curve.

Due to ignoring the influence of foundation pit unloading effect on the bearing properties of uprooted piles, the accuracy of in-situ test results needs to be studied when the excavation unloading area is large, and the current research on uplift piles mostly reflects the bearing properties of piles based on pile side friction resistance, and there are few studies on the normal pressure of pile-soil interface on pile sides. Compared with the frictional resistance of the pile side, the normal pressure of the pile-soil interface on the pile side can intuitively reflect the influence of foundation pit excavation and unloading on the bearing properties of the uprooted pile. In view of this, the combination of model test and numerical simulation was used to explore the stress response and deformation law of uplift piles under excavation and unloading conditions by changing the variables such as foundation pit excavation range and pile roughness, and then the bearing mechanism of uplift piles was revealed. The results show that the unloading effect of foundation pit excavation is related to the depth and width of the foundation pit, the effective pile length and the pile side roughness, according to the degree of influence: the effective pile length> the depth of the foundation pit> the roughness of the pile side > the width of the foundation pit. When the width of the foundation pit is greater than the critical value, the increase of the width of the foundation pit has little effect on the bearing characteristics of the uplift pile. Under the condition of the same effective pile length, the normal stress of the excavated pile side is proportional to the depth of the foundation pit and inversely proportional to the width of the foundation pit, and the relationship with the pile roughness is small. Under the condition of the same effective pile length, the frictional resistance of the pile after excavation is directly proportional to the depth of the foundation pit and the roughness of the pile, and inversely proportional to the width of the foundation pit.

To investigate the flexural bearing capacity of timber-concrete composite beams, Yunnan pine was selected as the base material, and high-strength self-tapping screws were used as shear connectors. Self-tapping screws were drilled into the timber to connect with cast-in-place concrete slabs, with partial slotting of the connection surface on the timber beam as a variable, to study the flexural performance of timber-concrete composite beams. Two groups of four specimens were designed in total, and a stepwise loading method was adopted to conduct four-point bending tests to analyze the mechanical properties of the composite beams. The results indicated that the overall performance of the composite beams was good, with the partially slotted design exhibiting better flexural stiffness and overall performance compared to the unslotted beams. Under the same load conditions, the deflection of the partially slotted beams was reduced by 57% compared to the unslotted beams, and the interface slip was reduced by 50%. Theoretical analysis results were in good agreement with the experimental findings, showing that the effective flexural stiffness and composite effect coefficient of the partially slotted beams were higher than those of the unslotted beams. The partially slotted design of the composite beams demonstrated superior overall performance, as well as improved stiffness and strength.