Table of Content

25 August 2025, Volume 53 Issue 8

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Contents



2025, 53(8):  0. 

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Intelligent Transportation System

Research on the Relationship Between Built Environment and Metro Ridership at Zone-to-Zone Level



LIU Jun, LUO Weijia, XU Xinyue

2025, 53(8):  1-10.  doi:10.12141/j.issn.1000-565X.240380

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Accurately characterizing the relationship between the built environment and urban rail transit ridership is an important prerequisite for understanding passenger demand. In response to the challenges of incomplete and high-dimensional sparse data in inter-station OD (origin-destination) studies, this paper proposed a research method of mapping relationship between built environment and ridership at the zone level. Firstly, a two-level station clustering method was developed by replacing individual stations with clusters (“cluster-over-point”) based on natural geographical characteristics and passenger flow destination features. Inter-cluster similarity was calculated to a-ddress the issue of data sparsity. Secondly, a built environment indicator system and corresponding description method were constructed from two dimensions: the attraction capacity of origin or destination clusters and OD acce-ssibility characteristics. Thirdly, a methodology based on the Gradient Boosting Decision Tree (GBDT) model was introduced to characterize the relationship between built environment features and passenger flow, delving into the influence intensity and threshold values of individual factors on passenger flow. Finally, the proposed method was validated using data from the Beijing Subway. Therefore, in the process of urban rail transit planning, priority should be given to optimizing network topology and improving transportation accessibility, followed by a deeper consideration of the impact of regional economic activities. The results show that the mapping relationship between built environment and passenger flow at zone-to-zone level has spatial and temporal heterogeneity, nonlinear characteristics and threshold effects. The zoning-based research perspective effectively addresses issues of data sparsity. OD impedance emerges as the primary feature influencing passenger flow, accounting for up to 38.40% of the explanatory power, while demographic and economic characteristics serve as secondary factors, exhibiting significant threshold effects. Therefore, in the process of urban rail transit planning, priority should be given to optimizing network topology and improving transportation accessibility, fo-llowed by a deeper consideration of the impact of regional economic activities. The research findings provide quantitative analytical tools for rail transit planners, assisting them in identifying the effective ranges of built environment indicators and adjusting spatial configurations. These insights offer valuable references for enhancing the operational efficiency of urban rail systems.

Research on Collaborative Transfer Under the Condition of Urban Rail Transit Passenger Flow Control



WANG Bao, LUO Xia, QIAO Xuan, SU Qiming

2025, 53(8):  11-19.  doi:10.12141/j.issn.1000-565X.240362

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To address the current lack of attention to the transfer of restricted passenger flows under urban rail transit network flow control scenarios, this study investigated the routing and capacity allocation of transfer vehicles under specific flow control conditions. Firstly, the utility and selection probability of passengers opting for transfer vehicles were analyzed and quantified across various route conditions. Then, a model for the design of transfer bus routes and capacity planning under flow control scenarios was proposed, aiming to minimize total expected travel time and the operational costs of transfer vehicles, and maximize the alleviation of passenger congestion in the rail transit network. To enhance model-solving efficiency, the model was divided into two subproblems: route optimization and service optimization. The first subproblem was transformed into a traveling salesman problem, with the resulting alternative route paths serving as input for solving the second subproblem. Based on Chengdu’s urban rail transit network and passenger flow data during the morning peak period, the effectiveness of the proposed model under different levels of flow restrictions was verified, and the preferences for the number of stops and the selection of transfer station locations were discussed. Results indicate that routes with 2 to 3 stops generally perform well in terms of the objective function, and the selection of stopping stations is highly concentrated, with a strong preference for 3 to 4 specific routes. As flow control intensity increases, there is a clear tendency to choose routes with fewer stops and shorter travel distances to meet rapid transfer demands. The number of scheduled trips increases approximately linearly overall; however, when the flow restriction intensity exceeds 0.8, a single route can no longer meet the transfer demand, and the linear growth trend no longer holds.

Research on the Joint Optimization of Shared Bikes and Demand-Responsive Connector



XU Hang, LI Xin, YUAN Yun

2025, 53(8):  20-28.  doi:10.12141/j.issn.1000-565X.240455

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Demand-Responsive Connector (DRC), as a flexible public transportation mode, can provide personalized bus services according to passengers’ needs and has been widely applied in urban areas both domestically and internationally. However, in actual operation, it faces the dilemma of balancing service efficiency and operational costs, as well as the challenge of achieving “door-to-door” services. To address these issues, a joint travel mode combining shared-bike transfer and DRC was proposed. By integrating the advantages of shared bikes and DRC, the coupling optimization of the two transportation modes can be realized, thereby improving the overall service efficiency and service level of public transportation. To this end, based on the continuous approximation method, discrete demand points and shared bicycle deployment locations were continuousized. The operating costs of the transit system, shared bicycle costs, and passenger travel time costs were derived and calculated. By minimizing the total system cost, the joint mobility system was optimized. With the goal of minimizing the total system cost, the coupling optimization of shared bicycles and demand-responsive buses was realized. To verify the effectiveness of the proposed joint travel system, an empirical study was conducted using the university town area of Chongqing as a case. The operation of the joint travel system under different scenarios was simulated and compared with the traditional DRC system without shared-bikes. The results show that the joint travel system can effectively address the operational problems of DRC. Compared with the traditional DRC system, the joint travel system can reduce the total system cost by up to 14.8%, the travel time saving by 15.2%, and the detouring saving of DRC vehicles by 29%. It is demonstrated that introducing shared bicycles as a first- and last-mile connection tool in demand-responsive transit systems can significantly reduce transit operating costs and passenger travel times. At the same time, it minimizes unnecessary detours by transit vehicles, optimizes transit routes, and greatly improves the efficiency and quality of public transportation services.

Evaluation Model for Eco-Driving Performance of Pure Electric Bus Drivers



ZHANG Yali, SHEN Yubo, YUAN Wei, ZHANG Kang, ZHANG Huiming

2025, 53(8):  29-41.  doi:10.12141/j.issn.1000-565X.240470

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Improving driver behavior is an important way to reduce vehicle energy consumption. Currently, many scholars have conducted extensive research on eco-driving behavior and proposed various eco-driving suggestions. However, there is a lack of evaluation methods specifically aimed at assessing the driving performance of pure electric bus drivers. In order to reduce the operating costs and energy consumption of electric buses, this study co-llected naturalistic driving data from electric buses. Firstly, the original data was pre-processed with unified sampling frequency, data cleaning, and parameter supplementation. Secondly, by selecting driver behavior characteristic parameters and vehicle operation parameters, the impact of bus driver driving behavior on energy consumption was analyzed. Based on the identified behavioral parameters that influence energy use, and taking each trip from the departure station to the terminal station as a unit, seven energy-related driving events were proposed: average start-up acceleration time, number of rapid accelerator pedal presses, duration of sustained high pedal opening, number of sudden accelerations, braking proportion during deceleration, duration of low-speed driving, and duration of economic speed driving. Afterwards, a multiple regression model for eco-driving level evaluation was established by analyzing the Pearson correlation coefficients between various driving event parameters and energy consumption per 100 kilometers, and the driving level of the driver during the journey was scored. Finally, based on the evaluation model, an eco-driving assistance feedback platform was built to help fleet managers better understand the eco-driving level of drivers. The results show that the proposed eco-driving level evaluation model for electric buses based on driving events has an accuracy of 93.52% and an average error of 6.48% in evaluating the eco-driving behavior. The model has a good effect on calculating eco-driving scores. The eco-driving assistance feedback platform can help fleet managers understand the operation status of buses and the eco-driving level of drivers, and help drivers understand their own driving situation.

A Study on the Optimization of Modular Autonomous Public Transit Services



ZHANG Jiyu, TANG Chunyan

2025, 53(8):  42-49.  doi:10.12141/j.issn.1000-565X.240355

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With the rapid development of intelligent connected technologies and autonomous driving, the emerging autonomous modular buses have attracted significant attention in the public transportation field. The autonomous modular buses can achieve flexible design of bus capacity through freely coupling/decoupling vehicles adapting to the uneven distribution of passenger demand in terms of space and time. However, the existing full-route service mode fails to fully leverage the flexible operational characteristics of modular buses to efficiently meet passengers' differentiated needs. Therefore, this study proposed a new service mode for autonomous modular buses, which combined the coupling/decoupling characteristics of modular buses with the differentiated service advantages of the skip-stop strategy to realize efficient and differentiated bus line supply. This paper first employed a discrete-time modeling approach combined with the extended Newell’s theory to develop an optimization model for autonomous modular bus skip-stop services, aiming to minimize passenger travel costs and operator costs. The model simultaneously optimized departure intervals, vehicle groupings, and skip-stop schedules.Firstly, this study adopts a discrete-time modeling method and an extended Newell theory to develop an optimization model for autonomous modular bus skip-stop service mode, with the optimization objectives of minimizing passenger travel costs and operational costs for the agency. It can simultaneously optimize bus headways, vehicle formulation, and skip-stop plans. By extending the Newell theory, the model expands from calculating passenger waiting and travel times at individual bus stops to efficiently calculating these times from the entire bus line system perspective, significantly reducing the modeling complexity. Secondly, taking Bus Route 110 in Dandong as a case study, an optimized operational scheme was proposed and compared under both off-peak and peak periods with the traditional fixed-capacity bus service model and the full-route modular bus service model. The results show that the proposed modular bus skip-stop service mode can greatly reduces the total system cost, saving 3.34% to 24.65%. Specifically, passenger waiting time costs and travel time costs are reduced by 7.49% to 48.52% and 2.31% to 6.28%, respectively. Moreover, during peak hours, modular bus dispatching is more frequent than during off-peak periods, with a tendency to adopt low-capacity vehicle groupings and skip-stop service strategies.

An Investigation into Expressway Merging Behavior and Safety Based on ExiD Data



WEN Huiying, HUANG Kunhuo, CHEN Zhe, ZHAO Sheng, HU Yuqing, HUANG Junda

2025, 53(8):  50-60.  doi:10.12141/j.issn.1000-565X.240437

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Expressway merging areas are characterized by frequent lane changes, complex driving environments, and intense traffic conflicts, making them high-risk zones for traffic accidents. Accurately understanding the relationship between vehicle operating status and traffic safety in these merging areas can provide a foundation for real-time accident risk prediction and the development of effective traffic safety control strategies. This study is based on vehicle trajectory data from the German ExiD dataset. By analyzing the changes in the relative positions of mainline outer-lane vehicles during the process from a vehicle entering the acceleration lane to merging into the mainline, the merging patterns in expressway merging areas were classified. To systematically describe the safety risks associated with merging, this study introduced the Time to Collision theory and developed a risk representation framework. This framework includes two levels of indicators: (1) a merging moment risk indicator based on two-dimensional TTC, which evaluates potential conflict at the moment of merging; and (2) a merging process risk indicator based on collision exposure time, which reflects the accumulated risk throughout the merging process. For model development, four machine learning algorithms—XGBoost, LightGBM, GBDT, and Random Forest—were used to build a classification model for merging risk. In addition, SHAP was applied to interpret the model and analyzed the key factors influencing merging risk. Experimental results show that the XGBoost-based risk identification model for expressway merging areas outperforms other models, achieving an overall accuracy of 95.52%. It also demonstrates superior performance in terms of accuracy, precision, recall, and F1-score. Furthermore, comparison among models indicates that incorporating merging duration and urgency significantly improves risk identification accuracy. SHAP analysis further reveals that merging risk is closely related to several factors, including the ave-rage and maximum speed differences with the leading vehicle on the mainline, the average distance to the leading vehicle, merging duration, the standard deviation of longitudinal acceleration during merging, and the speed of the merging vehicle.

A Study on the Impact Mechanism of Human-Machine Mixed DrivingTraffic Flow Under Occasional Accident



2025, 53(8):  61-72.  doi:10.12141/j.issn.1000-565X.240491

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With the ongoing development of integrated vehicle-road-cloud systems, mixed traffic flow composed ofhuman-driven vehicles (HDVs) and connected and autonomous vehicles (CAVs) is expected to become the dominantform of future transportation. To explore the influence mechanism of CAV human-like driving strategy and sensinginformation capability on human-machine mixed driving traffic flow under occasional accident, this paper improvedthe cellular automata rules under the framework of the KKW (Kerner-Klenov-Wolf) model, introduced the synchroni⁃zation factor to consider the CAV human-like driving strategy, and constructed the HDV and CAV car-followingrules for different following modes. Considering the lane-changing demand in accident scenarios, a multi-lane dis⁃cretionary lane-changing strategy incorporating the lane preference of HDVs and CAVs was constructed, along witha mandatory lane-changing rule for CAVs based on lane-changing pressure. Sensitivity analysis was conducted ondifferent lane-changing pressure parameters. Through numerical simulations, the effects of varying traffic volume,CAV penetration rate, CAV perception range of accident information, and CAV human-like driving strategies onmixed traffic flow were analyzed. The results show that the increase of CAVs can effectively alleviate the congestionof traffic flow after occasional accident and limit the spatial and temporal scope of congestion, and the average speedand average traffic volume of the low traffic volume are increased by 11. 74% and 6. 32%, respectively, when CAVpenetration rate is increased from 0 to 1. The enhancement is lower than that of medium and high traffic volume. Inthe case of medium and high traffic volume with CAV penetration rate greater than 0. 4, with the increase of CAVaccident information sensing range, the congestion space in the merging area is gradually dispersed, and traffic effi⁃ciency is improved. With the transition of the CAV human-like driving strategy from aggressive to conservative, theflow of the human-machine mixed driving traffic flow is gradually reduced, and the range of slow queues expands,traffic congestion gradually worsens, and the trend of speed fluctuations in each lane gradually converges over time.




Collaborative Control for Urban Expressway Mainline and On-Ramp Metering in Connected-Vehicle Environment



WU Haodu, SHI Yang, ZHAO Junteng, SUN Jian

2025, 53(8):  73-86.  doi:10.12141/j.issn.1000-565X.240403

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With the increasing application of Connected and Autonomous Vehicle (CAV) technologies in active traffic management, Variable Speed Limit (VSL) strategies have become crucial for improving traffic flow efficiency and safety. To address the issues of decreased traffic capacity and abrupt speed variations caused by traffic conflicts in urban expressway merging areas, a cooperative variable speed limit (VSL) control strategy was proposed for the mainline and on-ramp under a connected vehicle environment. Firstly, a mainline traffic flow prediction model based on Motorway Traffic Flow Network Modle (METANET) was adopted, constructing a bi-objective function to minimize the total travel time and distance, using Model Predictive Control (MPC). Then, the variable speed limit control problem was modelled as a Markov decision process, with a composite reward function based on average speed, throughput, and vehicle delay. By introducing Deep Q-network (DQN), the optimal on-ramp speed limits under different traffic flow conditions were calculated and disseminated to CAVs through Vehicle-to-Infrastructure (V2I) communication. Finally, the proposed coordinated control strategy was simulated and tested using the North Third Ring Expressway in Xuzhou, China as a case study. The empirical results based on SUMO microsimulation demonstrate that the proposed strategy, compared to the scenario with speed control only on the mainline, reduces the total travel time of network vehicles by 8.51%, increases the average speed by 14.49%, and reduces traffic density fluctuations by 14.81%. These results demonstrate that the proposed method can effectively improve traffic flow efficiency in merging areas under a connected vehicle environment, reduce speed differences between mainline and ramp vehicles, and shrink the spatiotemporal scope of congestion, thereby enhancing the stability of urban expressway traffic flow.

Architecture & Civil Engineering

Study on Axial Compression Performance of UHPC Fully Encased Q690 High-Strength Steel Composite Stub Columns



LI Tao, HE Zhengbo, WEI Guozheng, CAO Hongyou

2025, 53(8):  87-99.  doi:10.12141/j.issn.1000-565X.240443

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To investigate the axial compression performance and strain compatibility of UHPC fully encased Q690 high-strength steel composite stub columns, this study designed, fabricated, and tested seven specimens under axial compression. The research parameters included the internal arrangement of steel wire mesh, the volume content of UHPC steel fibers, the stirrup spacing, and the cross-section type of steel profiles. It investigated the deformation failure process, ultimate failure mode, and peak bearing capacity of each specimen. The results showed that the UHPC fully encased Q690 high-strength steel composite stub columns exhibited excellent axial compression bea-ring capacity and deformation performance, and the strain compatibility between core UHPC and Q690 high-strength steel can be achieved at peak load. By referring to the bearing capacity calculation methods mentioned in various national codes, including China, Europe, and the United States, theoretical calculations of the axial compression ultimate bearing capacity of the UHPC fully encased Q690 high-strength steel composite stub columns were conducted and the results were compared with the experimental results. It shows that Tthe calculated results are in good agreement with the experimental results, providing a reference for calculating the axial compression bearing capacity of UHPC fully encased Q690 high-strength steel composite stub columns.

Study on the Influence of Rounded Corner and Rough Strips on Wind Load of CAARC Model



YANG Yi, WU Jian, WANG Xin, XU Zhouyang

2025, 53(8):  100-110.  doi:10.12141/j.issn.1000-565X.240485

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Modern high-rise building façades often feature local elements such as sunshades and vertical decorative strips, and corner areas of buildings commonly adopt design measures like rounding or curving. The influence of these common architectural design features on wind loads cannot be ignored, and the current code needs to be improved., This paper takestook the CAARC high-rise building standard model as the research object, and studied the influence of rough strips and rounded corner on the wind load of the structure through a series of rigid model pressure measurement wind tunnel tests and high-frequency balance force tests. The studies show that: 1) Under the smooth model condition, with the increase of rounding angle from 0% to 10%, the absolute value of the peak negative pressure in the corner area of the windward surface of the building will gradually increase, and with the maximum increase is of about 38.4%; The global body shape coefficients of the structure will gradually decrease, and the maximum reduction of the global body shape coefficients in the X direction and Y direction is about 26.3% and 39.9%, respectively. 2) Under the condition of arranging vertical or grid rough strips with a thickness of 1.5 mm on the surface of the model, it is beneficial to reduce the absolute value of the peak negative pressure in the corner and middle of the structure, with a maximum reduction of 13.68%; For the global body shape coefficients of the structure, the rough strip model is slightly lower than the smooth mode. 3) The influence of arranging rough strips and rounded corner on wind pressure of building corner areas is not a simple superposition relationship. When both rough strips and rounded corner are arranged, the absolute value of the peak negative pressure in the corner area increases, with a maximum increase of 45.1%. 4) After the installation of roughness elements or the rounding of corner areas, the peak value of the crosswind power spectrum decreases, and the dimensionless frequency corresponding to the spectral peak increases.

Stability Analysis of the Network Arch Bridge Considering Nonlinear Effects



JIANG Zuqian, XIAO Rucheng, SONG Chaolin, SUN Bin, WANG Yeteng, JIANG Haixi

2025, 53(8):  111-122.  doi:10.12141/j.issn.1000-565X.240552

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A networked suspension cable arch bridge is a type of truss arch bridge system where at least two inclined suspension cables intersect, replacing the traditional vertical suspension cables. The cross-arranged networked suspension cables can effectively enhance the vertical stiffness and overall mechanical performance of traditional arch bridges, which has attracted attention in the field of bridge engineering. However, with the increasing span of arch bridges and the widespread use of thin-walled steel structures, structural stability issues have become more prominent. In particular, the risk of instability in steel arch ribs, which are primarily under compression, has become a key factor limiting its engineering application. To systematically analyze the stability performance of a networked suspension cable arch bridge and to explore the impact of different structural arrangement parameters on the overall stability of the structure, this study comprehensively considered geometric nonlinearity, material nonlinearity, and structural initial defects. A parametric spatial bar finite element model was established using nonlinear finite element methods to analyze the effects of varying cable tension forces on the overall stability. The displacement response and nonlinear instability critical load of key nodes on the arch ribs under load were calculated. The results from national and international standards were compared with those obtained using nonlinear finite element methods. Additionally, the study investigated the influence of different rise-to-span ratios, arch rib inclination angles, and cable inclination angles on the stability of the networked suspension cable arch bridge. Results show that variations in the suspension cable tension have little impact on the overall stability of the networked suspension cable arch bridge. The ultimate capacity of arch ribs based on standard methods is more conservative than that obtained through the nonlinear finite element method.The lateral overall stability of network arch bridges improves with increasing rise-to-span ratio and arch rib inclination, while it first increases and then decreases with the increase in cable inclination angle. The lateral stability performance of the bridge is optimal when the cable inclination angle is set between 50°and 60°.

Materials Science & Technology

Mix Design and Performance Optimization of Stone Powder-Rich Manufactured Sand Concrete



ZHANG Tongsheng, LI Kai, TAN Kanghao, CHANG Zezhou, TAN Yanchen, TANG Liang, YANG Donglai, ZENG Siqing

2025, 53(8):  123-136.  doi:10.12141/j.issn.1000-565X.250042

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During the production of manufactured sand, a large amount of stone powder was sieved and buried, leading to resource waste and environmental pollution. To improve the utilization rate of manufactured sand stone powder, this study explores the high-value application of waste stone powder in concrete. By treating the stone powder in manufactured sand as a cementitious component to partially replace cement, the effects of granite stone powder on the microstructural evolution of hardened cement paste were investigated using XRD, TG, SEM, and other characterization methods, leading to the identification of the optimal cement replacement range. Furthermore, by adjusting the stone powder content in manufactured sand, coarse aggregate gradation, sand ratio, and water-to-binder ratio, the workability and mechanical properties of concrete were optimized. The study reveals the mechanism by which paste volume fraction influences concrete’s workability and mechanical performance, and successfully produced low-cost concrete with acceptable workability and mechanical strength using manufactured sand with a high stone powder content. The results show that cement paste with 10% stone powder retained a denser microstructure, as the amount of hydration products showed negligible reduction compared to that of pure cement paste after 7-day and 28-day curing. However, when the substitution of cement with stone powder exceeded 20%, the amount of hydration products decreased significantly by more than 20%, leading to a porous microstructure and lower compressive strength compared to that of pure cement paste. When manufactured sand (MS) with high stone powder content is used in concrete production, the dosage of superplasticizer needs to be increased slightly under the same slump requirement. Additionally, the optimal workability and mechanical properties of MS concrete were achieved when the volume fraction of paste lay in the range of 31~32%. Consequently, C30, C40, and C50 concretes meeting target property requirements were prepared using MS with 15.1%, 16.5%, and 18.7% stone powder content, respectively, resulting in cement consumption reductions of 54, 63, and 92 kg/m³, and thereby significant reductions in cost and carbon emissions.

A Simulation Model of 3D Printed Concrete for Penetration Resistance



ZHOU Jiehang, DU Longyu, LAI Jianzhong, YIN Xuexiang, YANG Mingyu

2025, 53(8):  137-148.  doi:10.12141/j.issn.1000-565X.240451

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3D printed concrete is a promising new construction technology with potential applications in military field. As a prerequisite for its application in the military field, 3D printed concrete should possess strong impact resistance, providing reliable protection for military equipment and personnel. Currently, experimental research on the impact resistance of 3D printed concrete is limited by cost issues. Therefore, the use of numerical simulation technology can improve research efficiency, reduce costs, and better reflect the failure processes and damage conditions of 3D printed concrete. However, current numerical simulation technologies for 3D printed concrete do not take into account its unique interface structure, and thus fail to fully reflect the mechanical properties of 3D printed concrete. Based on the results of chloride ion penetration experiments, this study quantitatively characterizes the proportion of the interface region in 3D printed concrete. Using this as a basis, and in conjunction with previous mechanical performance studies, a numerical simulation model for the penetration resistance of 3D printed concrete was established, and its failure behavior was further investigated. By comparing the numerical simulation results with penetration experiment data, it was found that the penetration depth error of the 3D printed concrete model is within 4%, demonstrating its high simulation accuracy. During the penetration process, the 3D printed concrete target exhibits a characteristic of damage concentration at the interface, with the energy absorption at the interface being greater than that in the non-interface regions. As the projectile velocity and target strength increase, the projectile may disintegrate during penetration, leading to a sudden reduction in penetration depth, which further affects the variation of projectile velocity during the penetration process. Measures such as interface reinforcement, improvement of the 3D printing process, and the addition of high-strength aggregates can effectively reduce the penetration damage depth of 3D printed concrete targets, thereby enhancing their penetration resistance.

Study of Dye Adsorption Properties of Cellulose-Based Nanocellulose Aerogels



CHEN Gang, AO Jie, HE Yingying, WANG Chunyu, ZHANG Cheng

2025, 53(8):  149-157.  doi:10.12141/j.issn.1000-565X.240587

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The issue of water pollution is becoming increasingly severe, highlighting the urgent need to develop efficient and sustainable methods for pollutant removal. This study proposed the use of ambient pressure drying to prepare a nanocellulose-based aerogel with high adsorption capacity for both anionic and cationic pollutants. Polyethyleneimine (PEI) was first attached to a carboxymethylated cellulose nanofiber (CNF) framework through electrostatic interactions. Then, γ-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA) were used for chemical crosslinking to form a hydrogel. Finally, through solvent exchange and ambient pressure drying, a low-density (18.80 mg/cm³) and high-porosity (92.06%) CNF/PEI composite aerogel (CPA) was obtained. This aerogel demonstrated excellent structural stability in water. Owing to the coexistence of anionic carboxymethyl and cationic amino groups, the aerogel exhibited strong adsorption capacity of aerogel per gram for both cationic and anionic dyes in complex wastewater environments. The maximum adsorption capacities of aerogel per gram for methylene blaue (MB) and Congo red (CR) were 516 mg and 2 090 mg, respectively,with removal rates of over 98% for both anionic and cationic dyes. In addition, the aerogel exhibited good structural stability and fatigue resistance. After soaking in an alkaline solution for a week, it remained intact, and after 10 cycles of compression in the wet state, its elasticity recovery rate remained at 60%. Compared to similar adsorption materials, CPA shows significant advantages in terms of adsorption capacity, amphoteric adsorption ability, and reusability. The preparation method proposed in this study is time-efficient and highly effective, making it suitable for large-scale production, with promising potential for application in industrial wastewater treatment.

Preparation and Application of Modified Chitosan/Laponite Composite Antimicrobial Material



LÜ Xiaojing, WEN Yuming, WANG Xiaoying, HU Jian

2025, 53(8):  158-166.  doi:10.12141/j.issn.1000-565X.250015

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Chitosan (CS) and laponite (LAP) are both biocompatible materials, and modification can enrich them with enhanced bioactivity. This paper investigates the preparation of a composite antibacterial material based on quaternized chitosan (QCS) and modified lithium montmorillonite, as well as its antibacterial performance in shampoo applications. QCS was degraded via microwave-assisted hydrogen peroxide oxidation to enhance its solubility, and LAP was organically modified with cetyltrimethylammonium bromide (CTAB) to impart its Malassezia adsorption capability, resulting in positively charged organic LAP. The successfully prepared QCS and CTAB-LAP composite materials were characterized and validated using Fourier-transform infrared spectroscopy, Zeta potential analysis, rotational rheometry, and scanning electron microscopy. Experimental results demonstrate d that QCS with different molecular weights exhibits good antibacterial performance in aqueous media, and the composite material of QCS and CTAB-modified LAP significantly enhances the antibacterial effect through synergistic action. By optimizing the dosage and ratio of the antibacterial agents, the study identified the optimal formulation of the composite antibacterial agent for use in both aqueous media and base shampoo. QCS of various molecular weights demonstrated excellent antimicrobial performance in aqueous media. The QCS and CTAB-LAP composite material exhibited a synergistic enhancement in antimicrobial effect. Optimal formulations for the composite antimicrobial agents in aqueous media and base shampoo were identified by varying the amount and ratio of the components. In aqueous solution, composite mixtures with mass ratios of 9∶1, 5∶5, and 1∶9 achieved 100% antimicrobial efficacy after 10-fold dilution and 5 minutes of Malassezia strain contact. When added to base shampoo at a 9∶1 ratio (total mass fraction 0.14%) and diluted 100-fold, the composite maintained significant antimicrobial efficacy, reaching up to 70% effectiveness compared to commercial chemical anti-dandruff products. This study highlights the potential of the QCS and CTAB-LAP composite for practical application in anti-dandruff shampoos and paves the way for the development of natural and eco-friendly antimicrobial materials.