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Compared with other point clouds, the airborne LiDAR point cloud has its own characteristics. The deep learning network PointNet++ ignores the inherent properties of airborne LiDAR point, and the classification precision is low. Therefore, we propose a framework based on the PointNet++ network. In this work, we proposed an interpolation method that uses adaptive elevation weight to make full use of the objects in the airborne LiDAR point, which exhibits discrepancies in elevation distributions. The class-balanced loss function is used for the uneven density distribution of point cloud data. Moreover, the relationship between a point and its neighbours is captured, densely connecting point pairs in multiscale regions and adding centroid features to learn contextual information. Experiments are conducted on the Vaihingen 3D semantic labelling benchmark dataset and GML(B) benchmark dataset. The experiments show that the proposed method, which has additional contextual information and makes full use of the airborne LiDAR point cloud properties to support classification, achieves high accuracy and can be widely used in airborne LiDAR point classification.

Rammed earth (RE) dwellings are characterized by accessible materials, low cost, and environmental sustainability. However, their poor seismic resistance limits their application. To address this issue, three conventional technical approaches have been developed: (1) adding cement to improve strength; (2) improving structural integrity using reinforced concrete ring beams and columns; and (3) embedding vertical steel bars in order to provide resistance against horizontal seismic actions. While effective, these methods rely on energy-intensive materials with high carbon emissions. In this study, we analyze the seismic damage characteristics and construction mechanisms of RE walls. The results reveal that the horizontal joints in RE walls significantly weaken their resistance to horizontal seismic actions. To mitigate this, three types of undulating joints are proposed and six specimens tested. The maximum horizontal loads of the specimens with local subsidence-type joints are 132.44 kN and 135.41 kN, respectively, which are approximately 50% higher than specimens with horizontal joints, whose maximum horizontal loads are 80.7 kN and 85.83 kN, respectively, while the maximum horizontal loads of the specimens with horizontally concatenated gentle arc-type joints are 151.17 kN and 173.58 kN, respectively, and they exhibit nearly double the shear capacity of the specimens with horizontal joints. Building on these findings and test results, we also include recommendations for integrating elegant RE wall texture design with seismic-resistant undulating joint technology.

Background Producing large amounts of soluble proteins from bacteria remains a challenge, despite the help of current various solubilizing fusion tags. Thus, developing novel tags is necessary. Antifreeze protein (AFP) has excellent solubility and hydrophilicity, but there are no current reports on its use as a solubilizing fusion tag. Additionally, there is no precedent for using retro-proteins (reverse sequence) as solubilizing fusion tags. Therefore, we selected the antifreeze protein AXX and obtained its retro-protein XXA by synthesizing the XXA gene for the development of a new solubilizing fusion tag. Results XXA exhibits better stability and ease of expression than AXX; hence, we focused the development of the solubilizing fusion tag on XXA. XXA fused with the tested inclusion bodies, significantly increasing the soluble expression compared with commonly used solubilizing fusion tags such as GST, Trx, Sumo, MBP, and NusA. The tested proteins became soluble after fusion with the XXA tag, and they could be purified. They maintained a soluble form after XXA tag removal. Finally, we used enzymatic digestion reaction and western blot experiments to verify that bdNEDP1 and NbALFA, which were soluble expressed by fusion with XXA, were active. Conclusion We developed the novel solubilizing fusion tag XXA, which could more effectively facilitate the soluble expression of inclusion bodies compared with current commonly used tags. XXA could function at both low and high temperatures, and its moderate molecular weight has a limited impact on the output. These properties make XXA an ideal fusion tag for future research and industrial production. Moreover, for the first time, we highlighted the broad potential of antifreeze protein as a solubilizing fusion tag, bringing retro-protein into practical application.

The high permeability of gravel sand increases the risk of water spewing from the screw conveyor during earth pressure balance (EPB) shield tunnelling. The effectiveness of soil conditioning is a key factor affecting EPB shield tunnelling and construction safety. In this paper, using polymer, a foaming agent, and bentonite slurry as conditioning additives, the permeability coefficient tests of conditioned gravel sand are carried out under different injection conditions based on the factorial experiment design. The interactions between different concentrations of conditioning additives are analyzed. A prediction model for soil conditioning during shield tunneling based on particle swarm optimization (PSO) and relevance vector machine (RVM) algorithms is proposed to accurately and efficiently obtain the soil conditioning parameters in the water-rich gravel sand layer. The experimental results indicate that the improvement effect of the foaming agent on the permeability of the conditioned gravel sand gradually diminishes with the growing concentration of bentonite slurry. Under conditions of high polymer concentration, further increasing the concentration of bentonite slurry and foaming agent has a weak impact on the permeability coefficient when the concentration of bentonite slurry exceeds 10%. The significance of main effects, first-order interactions, and second-order interaction on the permeability of conditioned gravel sand are as follows: polymer concentration (A) > foaming agent concentration (B) > bentonite slurry concentration (C) > first-order interactions (A × B, A × C, B × C) > second-order interaction (A × B × C). The first-order interaction mainly manifests as a synergistic effect, while the second-order interaction primarily exhibits an antagonistic effect. Case studies show that the maximum relative error between predicted and experimental values is less than 3%. A field application of shield tunneling demonstrates the good performance of real-time optimization of soil conditioning parameters based on the PSO–RVM algorithm. This research provides a new method for evaluating the effectiveness of soil conditioning in the water-rich gravel sand layer.

In contemporary cities, road collapse is one of the most common disasters. This study proposed a framework for assessing the risk of urban road collapse. The framework first established a risk indicator system that combined environmental and anthropogenic factors, such as soil type, pipeline, and construction, as well as other indicators. Second, an oversampling technique was used to create the dataset. The framework then constructed and trained a convolutional neural network (CNN)-based model for risk assessment. The experimental results show that the CNN model (accuracy: 0.97, average recall: 0.91) outperformed other models. The indicator contribution analysis revealed that the distance between the road and the construction site (contribution: 0.132) and the size of the construction (contribution: 0.144) are the most significant factors contributing to road collapse. According to the natural breaks, a road collapse risk map of Foshan City, Guangdong Province, was created, and the risk level was divided into five categories. Nearly 3% of the roads in the study area are at very high risk, and 6% are at high risk levels, with the high risk roads concentrated in the east and southeast. The risk map produced by this study can be utilized by local authorities and policymakers to help maintain road safety.

This study explores the deformation characteristics of surrounding rock during tunnel construction through fault fracture zones. A numerical model is established using ABAQUS to analyze the interaction between the shield machine, support system, and geotechnical materials. The model incorporates key factors, including palm face support force, grouting pressure, and the friction between the shield shell and surrounding rock. The results show that the plastic zone of the surrounding rock is concentrated within the fault zone and at the junction with normal rock, propagating along the contact surface. In the loosening zone, stress and strength are significantly reduced, leading to crack expansion and plastic slip. Without adequate support, these conditions can result in tunnel destabilization. The displacement of the surrounding rock is most prominent during the detachment of the shield tail and the synchronized grouting phase. These findings provide valuable insights for improving tunnel construction safety and stability in fault fracture zones, where the integrity of the surrounding rock is compromised by fractures and fissures. However, the constructed models may restrict the ability to capture all complex material behaviors and interactions that could arise in actual field conditions.

Cement-sand reinforced soft clay (C-SRSC) is a complex multiphase geomaterial. Its strength is determined by the physical properties of the internal multiphase substances and the coupling mechanical response between various phases of substances. By considering the effect of the particle size and content of sand particles on the unconfined compressive strength (UCS) and failure mechanism of C-SRSC, the C-SRSC is divided into two phases of the cement soil matrix and sand particles to construct a micro cell model of C-SRSC. Based on the strain gradient theory, the theoretical model of the UCS of C-SRSC based on the physical mechanism at the microscale is derived. Forty five groups of UCS tests were conducted to analyze the effect of sand particle size and content on the UCS of C-SRSC, and to calculate the theoretical model parameters. The results show that the UCS of C-SRSC increases with increasing curing age, cement content, and sand particle content, and decreases with the increasing sand particle size. The theoretical model of the UCS of C-SRSC based on physical mechanism initially verified the consistency of the experimental and theoretical results.

This study evaluates the vertical stress transmission through a sand–tire mixture layer under impact, focusing on this innovative blended material that can impact underground structures such as tunnels or pipelines. By conducting consolidated undrained triaxial tests, the friction angle (φ) of the sand–tire mixture was determined, ranging from 29° for pure tire to 41° for pure sand. The vertical stress factor (α), representing the ratio of response load to applied load, was found to decrease significantly with increased tire content, with a reduction of up to 50% for mixtures containing 20% tire. Additionally, the vertical stress response decreased from 35 kPa for pure sand to as low as 15 kPa for mixtures with a high tire content under a consistent applied load of 65 kPa. This study not only presents a methodological advancement in analyzing sand–tire mixtures under dynamic loads but also suggests a sustainable approach to utilizing waste tire material in civil engineering projects, thereby contributing to environmental conservation and improved material performance in geotechnical applications.

Construction using earth materials demonstrates ecological sustainability using locally sourced natural materials and environmentally friendly demolition methods. In this study, the environmental impact of adding cement to soil materials for rammed earth farmhouse construction in rural China was investigated and comparatively simulated using the One Click LCA database, focusing on the conflict between sustainability objectives and the practical aspects of cement addition. By analyzing how the addition of cement aligns with local construction practices and addressing the debate surrounding the inclusion of cement in rammed-earth construction, our objective is to provide insights into achieving a balance between the environmental impact and the pragmatic considerations of using cement in earthen building practices. Three local structure scenarios are evaluated via simulations: cement-stabilized rammed earth wall, fired brick wall, and a localized reinforced concrete frame structure. The quantitative environmental impacts are assessed, and the qualitative differences in adaptation, economic sustainability, and other factors are examined in the context of present-day development in rural China. The results show that the use of cement-stabilized rammed earth wall-supported structures is associated with higher embodied carbon emissions compared to structures supported by reinforced concrete frames and enclosed by brick walls; however, these emissions are lower than those for brick wall-supported structures while effectively meeting the structural requirements. In addition, the use of cement-stabilized earth for perimeter walls simplifies material management and disposal throughout the building’s life cycle, and the cost-effectiveness of cement has been found to be substantially greater than that of reinforced concrete frames and brick structures, improving economic viability and social acceptability, especially among low-income communities in rural areas

Vehicle fuel cell systems release a large amount of heat while generating electricity. The suitable thermal management system must be built to ensure system performance and reliability. Based on the analysis of the working principle of the vehicle fuel cell thermal management system, the paper establishes a control-oriented fuel cell thermal management. The stack, air cooler, hydrogen heat exchanger, bypass valve, heat sink, and cooling water circulating pump model are taking into account. System model, and the relationship between stack current, coolant flow rate, fin surface wind speed, bypass valve opening, and fuel cell temperature are in established in simulation experiments. The paper discusses their effects on system as a whole, air coolers, hydrogen heat exchangers, and the influence of the temperature difference between the inlet and outlet of the radiator. The simulation results can provide guidance and help to design the fuel cell thermal management control system.