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Table of Content

    25 April 2025, Volume 53 Issue 4
    Architecture & Civil Engineering
    JIANG Tao, WANG Jing, WANG Yongdi
    2025, 53(4):  1-12.  doi:10.12141/j.issn.1000-565X.240260
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    Due to the natural advantage of pedestrian flow in rail transit hubs, three-dimensional and composite commercial space above rail transit hub has become a new construction model. The commercial space above rail transit hub has become an important place for passengers, commuters, and citizens to engage in consumption and social activities. However, The development volume of most commercial space above rail transit hub is relatively large, and the spatial organization relationship is complex. It is easy to encounter problems such as mismatched functional requirements, insufficient supply of service facilities, chaotic flow organization, low transfer efficiency, and poor spatial quality, resulting in insufficient guidance of pedestrian flow and low space utilization, which affects the vitality of commercial spaces and thus affects the healthy operation of commercial spaces. Therefore, starting from the study of the vitality of commercial space on the top, the constituent elements of commercial space above rail transit hub are defined from three dimensions: functional organization, flow line organization, and spatial construction. Corresponding evaluation indicators are constructed, and data analysis methods such as spatial syntax theory and correlation analysis are introduced to quantitatively study typical cases built in China. The key elements that affect spatial vitality are summarized, and finally, design strategies are proposed based on practical projects, providing design references for future related designs and bringing new insights to related theoretical exploration.

    CHENG Jin, SUN Kedi, YUAN Yi
    2025, 53(4):  13-21.  doi:10.12141/j.issn.1000-565X.240076
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    High costs and significant traffic volumes characterize long-span suspension bridges, which play a crucial role in transportation networks. As a control engineering project, deterministic analysis methods, such as the finite element method, are currently employed to calculate and analyze the safety of these bridges. However, in practical engineering, structural parameters exhibit uncertaintyand simultaneously, variability and correlation exist in spatial distribution. Hence, the influence of random field factors is incorporated. A numerical analysis method, combined with random field and reliability theory, was proposed for the reliability assessment of long-span suspension bridges. The components and implementation process of the method were introduced, and corresponding analysis programs were developed. The accuracy and applicability of the method and programs were validated through several examples. Finally, taking the three-tower four-span suspension bridge, the Oujian North Bridge, as an engineering case, the reliability of its deflection under normal operating limit states was evaluated. The impact of random fields on the deflection reliability index of the Oujian North Bridge was analyzed. Results indicate that considering random fields yields a deflection reliability index smaller than that obtained without considering them, suggesting that the spatial variability of structural parameters in long-span suspension bridges is neglected, leading to an overestimation of deflection reliability in normal service limit states.
    JIANG Zhengrong, LIU Xiaoliang, SHI Kairong, et al
    2025, 53(4):  22-29.  doi:10.12141/j.issn.1000-565X.240092
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    The initial geometric imperfection is one of the important factors affecting the static stability analysis of spatial structures. The current research mainly focuses on the overall imperfection (nodal installation deviation) and the initial curvature of members, but relatively insufficient on the initial eccentricity of members, and the related work has not been involved in the effect analysis of the initial eccentricity of members on the stability bearing capacity of cable-supported cylindrical reticulated shells. In view of this, a simulation method of introducing the initial eccentricity of members by the end rigid rod was proposed in this paper. On this basis, the random imperfection mode method was applied to introduce the initial eccentricity of members in the perfect structure and the overall imperfection structure in turn, then the elasto-plastic overall process analysis was carried out to investigate the effect laws of the initial eccentricity of members and the two kinds of imperfections imposed simultaneously on the nonlinear buckling behaviors of cable-supported cylindrical reticulated shells. The results show that compared with the perfect structure, the coefficients of stability bearing capacity of cable-supported cylindrical reticulated shells are not remarkably reduced when considering the initial eccentricity of members only, and the maximum reduction reaches 8.27%, thus the structure is not much sensitive to the initial eccentricity of members. When considering the overall imperfection and the initial eccentricity of members simultaneously, the coefficients of stability bearing capacity of cable-supported cylindrical reticulated shells are significantly reduced by 27.64%, but the decreasing ranges are slightly smaller than their sums separately introduced by the two kinds of imperfections. The overall imperfection and the initial eccentricity of members introduced in the meantime have a certain extent coupling effect on the stability bearing capacity of cable-supported cylindrical reticulated shells, and the effect of the former is more significant.

    DONG Yongcan, YUAN Xingfei, LI Shu, et al
    2025, 53(4):  30-39.  doi:10.12141/j.issn.1000-565X.240270
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    Inspired by the structural configuration of ribbed series cable domes, a novel rib-patterned deployable antenna structure is proposed in this paper. First, a basic deployable module with driving-locking joint is designed. Through assembling basic deployable modules, the stretching arm is constructed and used as the radial support rib. Then, the rib-patterned deployable structure is established by combining multiple stretching arms and loop cables. In fully deployed state, this deployable antenna structure can be regarded as a cable-beam system, and the modal analysis of this system is conducted accordingly through finite element simulation. It is found that the proposed deployable structure displays relatively higher structural stiffness compared with a cable-rib tension deployable antenna structure of the same size. On this basis, for a large aperture rib-patterned deployable antenna structure design scheme, deployment simulations of the single stretching arm and the entire antenna structure are carried out respectively. The results show that the proposed structure can be successfully deployed in place and locked, which further demonstrate the feasibility and effectiveness of his antenna scheme. This study demonstrates that the newly proposed rib-patterned deployable antenna structure combines the advantages of the high rigidity of truss-based deployable structures and the high fold ratio of rib-based deployable structures. It provides a valuable reference for the structural design of large-aperture antennas in the future.

    FAN Xueming, ZHOU Xiaopeng, YE Xiaohang, et al
    2025, 53(4):  40-49.  doi:10.12141/j.issn.1000-565X.240332
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    Steel structure has multiple advantages such as low carbon and environmental protection, light weight and high strength, and excellent seismic performance, and has been widely used in high-rise buildings, large-span buildings and some civil buildings, but its inherent susceptibility to buckling, corrosion, and high cost impede the further application of steel structure. Current measures to prevent buckling and corrosion of steel structures can greatly increase the cost of the structure and have a negative impact on the structural load-bearing capacity. Ultra-high performance concrete (UHPC) is a new type of fibre-reinforced cementitious composite material based on the theory of maximum packing density, which has high strength and deformation capacity, and has excellent performance in terms of water permeability, chloride permeability, and freeze-thaw resistance and other durability. Nowadays, they are widely used for mechanical and durable reinforcement of various structures. Recent research work has shown that the combination of steel structures and ultra-high performance concrete (UHPC) can effectively complement each other. This paper is based on a new type of combined beam of I-beam covered with a thin layer of UHPC, which has been widely used, and a sample database is established by ABAQUS finite element analysis software. Using the radar diagram method to put forward the combined beam shear performance and shear cost-effective comprehensive evaluation indexes, using the response surface - Monte Carlo method, the design of four kinds of response surface combined beam web size parameters for analysis. The analysis results show that there is a significant positive correlation between the shear performance of the combined beam and its cost-effectiveness. In addition, with the increase of I-beam web thickness, the shear resistance and cost performance first increase and then decrease, and reach the peak value at a specific thickness. The results of this paper are of great engineering significance for optimising the design of I-beam outsourced UHPC composite beams.

    WANG Suguo, QIU Wei, CHEANG Yi
    2025, 53(4):  50-60.  doi:10.12141/j.issn.1000-565X.240310
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    In order to study the influence of stirrup constraint effect on axial compression performance of ultra-high strength concrete precast column,an axial compression contrast experiment between full-size ultra-high strength concrete column and the ordinary column were carried out.Based on the experiment,36 full-size ultra-high strength concrete columns were designed in finite element analysis to investigate the effects of stirrup form,stirrup spacing,and stirrup diameter on the compression performance of ultra-high strength concrete columns.By considering the constraint effect of stirrup,a modified calculation formula of axial compression capacity of ultra-high strength reinforced concrete column was proposed.Furthermore,it was compared with the calculation formula in Code for Design of Concrete Structure.The results showed that:the ultimate bearing capacity of equal-strength designed ultra-high strength concrete column is higher than that of ordinary concrete column.But it is more brittle than ordinary concrete,especially when reaching the ultimate bearing capacity,the concrete of ultra-high strength concrete column breaks more obviously than that of ordinary concrete column; the constraint effect of stirrup on the core area concrete can improve the axial compressive bearing capacity of ultra-high strength concrete column,and stirrup type,stirrup spacing and stirrup diameter can influence significantly the axial compressive ultimate bearing capacity and peak compressive strain of ultra-high strength concrete column; compared with the calculation formula of Code for Design of Concrete Structure,due to the consideration of the constraint effect of stirrup on the core area concrete,it can better use of material by using the proposed calculation formula to assess design value of axial compressive capacity of ultra-high strength concrete column.

    Mechanical Engineering
    LI Yong, WANG Huipan, HE Jiabin, et al
    2025, 53(4):  61-71.  doi:10.12141/j.issn.1000-565X.240208
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    The development demand for electronic products, characterized by miniaturization, lightweight, and low cost, poses significant challenges to the design and manufacturing of heat dissipation modules. To address the heat dissipation challenges of thin and high-performance routers, the paper conducted experiments to analyze and compare the heat dissipation characteristics of seven specifications of aluminum plates under natural convection and micro-convection conditions. The results indicate that under natural convection conditions, for heat source powers ranging from 3-6W, the heat dissipation performance of square pin-fin  aluminum plates is optimal, compared to smooth surface aluminum plates, the average Nusselt number increases by approximately 18%, and the product of heat transfer coefficient and heat transfer area increases by about 17%, resulting in a decrease in heat source temperature by approximately 2°C; round pin-fin aluminum plate compared with the smooth surface aluminum plate, the average Nussel number is increased by 7%, the product of heat transfer coefficient and heat transfer area is increased by about 5%, and the heat source is reduced by about 1.3℃. Surface treatment further enhances the heat dissipation performance, with sandblasted square pin-fin aluminum plates leading to a temperature reduction of 2-3.9°C, and nano-carbon-coated square pin-fin structured aluminum plates resulting in temperature reductions of 5.3-8.6°C; with sandblasted round pin-fin aluminum plates leading to a temperature reduction of 1.9-2.5°C, and nano-carbon-coated square pin-fin structured aluminum plates resulting in temperature reductions of 4.9-7.7°C. Meanwhile, under micro-convection conditions with a wind speed of 2m/s, round pin-fin aluminum plates exhibit optimal heat dissipation performance,compared to smooth surface aluminum plates, the average Nusselt number increases by approximately 8%, and the temperature of the heat source can be reduced by 3.6°C at 6W, with an 18% reduction in thermal resistance; square pin-fin aluminum plate  compared to smooth surface aluminum plates, the average Nusselt number increases by approximately 6%, and the temperature of the heat source can be reduced by 2.4°C at 6W, with an 11% reduction in thermal resistance. As the heat source power increases, aluminum plates with surface microstructural features demonstrate better heat dissipation performance compared to smooth surface aluminum plates.

    HE Zhe, ZHANG Yuying, LIU Shangkun, et al
    2025, 53(4):  72-80.  doi:10.12141/j.issn.1000-565X.240173
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    Abrasion grinding wheels lower the material removal rate and increase the grinding temperature. To avoid the negative influence of the mentioned issues on the grinding process, replacing grinding wheels in time was necessary. This paper proposed a method predicting the wear and service life of grinding wheels by applying artificial neural network, through which grinding wheels could be replaced timely and reasonably. The basic theory of the method as follows: A series of wear parameters was abstracted from the axial acceleration signal of grinder motor shaft. By applying Z-score transformation, the wear parameters’ dimension was removed and comparability was improved. After that, according to mean gain, the XGBoost algorithm was employed to filter the most relevant features that are strongly correlated with the wheel's service life. A fusion strategy integrating wear time and wheel wear volume was adopted as the criterion for assessing the wear and service life. Constructing a neural network model that mapped the filtered feature parameters to both the wear volume and the grinding wheel thickness, followed by network training and validation. Experimental results showed that, in train and validation set, the judgment accuracy and prediction precision of this method was basically the same. The judgment accuracy of grinding wheels’ wear was 87.8%, with errors primarily concentrated in the transition interval when wear changed. The prediction precision of the grinding wheels’ service life was -5.3% in validation set. Also, this method showed a good versatility under various grinding process parameters.

    CHENG Haiying, LI Nanxi, MA Dengcheng, et al
    2025, 53(4):  81-89.  doi:10.12141/j.issn.1000-565X.240300
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    When the cold recycling machine sprays foamed asphalt, asphalt is easy to accumulate at the nozzle, and the flow of each nozzle is uneven. To solve the above problems, it is necessary to increase the pressure of foamed asphalt nozzle to reduce asphalt accumulation and balance the flow of each nozzle. This article first starts from the essence of asphalt foaming behavior, and based on the multiphase flow mixing theory, considered the changes in asphalt viscosity and water state during the asphalt foaming process. The viscosity temperature characteristic function of asphalt and the phase transition function of water were introduced into the calculation model to modify the fluid volume (VOF) model and establish a control model for asphalt foaming behavior. Secondly, numerical simulations were conducted to compare the nozzle pressure and flow rate during the asphalt foaming process with experiments, and it was found that the errors of the asphalt foaming behavior control model in terms of nozzle pressure and flow rate were 9.2% and 7.7%. Finally, based on the above asphalt foaming behavior model, the numerical simulation model of foamed asphalt spraying device was constructed. According to the designed experimental scheme, the spraying process of foamed asphalt was simulated numerically. Based on the simulation results, a Kriging surrogate model was constructed on the Isight platform, and a multi-objective optimization model was established with the goal of improving outlet pressure and reducing the mass flow rate of each nozzle. The multi-objective optimization model was solved by the NSGA-II algorithm. The Pareto solution set was obtained. The optimization results were obtained by analyzing the Pareto solution set. The results show that when the asphalt pipe diameter is 0.74a, the foaming pipe diameter is 0.58b, the foamed asphalt nozzle diameter is 0.6c, and the number of foamed asphalt nozzles is d, the performance of the foamed asphalt spraying device was optimal. Under the premise of considering the characteristics of asphalt foaming behavior, the performance of foamed asphalt spraying device is improved.
    JIA Huayu, ZHENG Huilong, ZHOU Hong, et al
    2025, 53(4):  90-101.  doi:10.12141/j.issn.1000-565X.230781
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    Rocket boosted zero-length launch is an important form of UAV launch , and the selection of launch parameters such as launch angle is directly related to the success or failure of the UAV launch mission. Aiming at the launch angle, booster angle, booster thrust and other key parameters coupled to influence the launch trajectory during the zero-length launch phase of the rocket boost, it is a technical challenge to optimally select the launch parameters under the constraint envelope. In this paper, a UAV is taken as the research object, dynamics and kinematics modeling is carried out for its launching phase, a six-degree-of-freedom nonlinear model is constructed, and parametric simulation software for UAV launching trajectory is prepared based on QT/C++ software. At the same time, an optimization method for UAV launch parameters based on SSA-optimized BP neural network is proposed, and the superiority of SSA-BP for launch parameters prediction is comprehensively evaluated based on MAE, MAPE, and RMSE error evaluation methods. The results show that the UAV launch ballistic simulation and launch parameter optimization model in this paper are effective and credible, and can provide technical support for the engineering design of UAV launch subsystem.

    ZHANG Yongshun, LIU Zhijun, LIU Zhenhu, et al
    2025, 53(4):  102-112.  doi:10.12141/j.issn.1000-565X.240377
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    In order to solve the problems of complex electromagnetic drive structure, difficult coupling magnetic field modelling and magnetic moment singularity in the current spherical joints, a permanent magnet flexible spherical wrist joint based on the rotational co-axis effect is designed. As for the driving principle, the spatial universal rotating magnetic field generated by the three-axis orthogonal combination coil is used as the driving source, in which, the decoupled coaxial magnetic moment generated by the permanent magnet rotor in synchronous rotation with the field is employed to drive the wrist to achieve two degrees of freedom motion of pitch and yaw. As for improving the systematic ability to resist external disturbance and chattering suppression, this paper adopts a non-singular fast terminal sliding mode control method based on fuzzy algorithm optimization to implement control. The Lyapunov function is used to prove the stability of the system. Simulation and experiments show that the system has good robustness and chattering suppression effect, as a result, output trajectory errors are reduced, high-precision and fast tracking of the expected trajectory of spherical joints are achieved and the adaptability to complex environments is improved.

    Food Science & Technology
    LI Bing, HE Min, HE Ni, et al
    2025, 53(4):  113-124.  doi:10.12141/j.issn.1000-565X.240221
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    The effects of laccase (LAC) and ferulic acid (FA) on the rheological properties, water migration characteristics, and microstructure of wheat dough were investigated in this study. Additionally, the changes in quality characteristics, such as specific volume, color, texture, and volatile matter of wheat bread, were also examined. Farinographic analysis showed that the softening degree of dough adding with LAC and FA (LAC+FA) was lower than that of the dough with or without FA. Correspondingly, the results of dynamic rheological and tensile tests showed that adding LAC or LAC+FA increased the resistance to extension and decreased the extensibility of dough, resulting in dough hardening. Furthermore, adding LAC and FA alone or in combination could convert T21b toT21a in the immobilized water, allowing the water to adhere to the dough's components more firmly and optimizing water migration in the dough. A more intact, continuous, and compact gluten network could also be observed in the dough with LAC+FA by using scanning electron microscopy (SEM). In terms of bread, adding LAC or LAC+FA reduced the hardness of bread cores with little effect on volatiles. Therefore, LAC or LAC +FA has a positive effect on improving the strength of dough and the physicochemical quality of bread.

    Food Science & Technology
    FAN Penghui, CHEN Guanghao, LIU Zirui, et al
    2025, 53(4):  125-134.  doi:10.12141/j.issn.1000-565X.240156
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    In order to explore the effect of different fractions of borneol essential oil on the motility and biofilm formation of Escherichia coli, Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyze the volatile components of borneol essential oil crude, light fraction, and heavy fraction. The impact of these three components on the biofilm formation of Escherichia coli ATCC 25922 was investigated. The research results showed that the crude borneol essential oil, light fraction, and heavy fraction had 27, 24, and 19 volatile components, respectively. The volatile components with the highest relative content were (-)-borneol (19.93%), cineole (19.36%), and (-)-borneol (28.92%), respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the three components against Escherichia coli were all 6.25 μL·mL-1, and they could delay bacterial growth at sub-inhibitory concentrations. At 1/2 MIC and 1/4 MIC concentrations, all three borneol essential oil fractions could reduce the swimming and swarming abilities of Escherichia coli and inhibit the biofilm growth, with the heavy fraction showing the strongest inhibitory effect. In conclusion, molecular distillation can enrich the antibacterial active components in borneol essential oil, effectively enhancing its added value, and has broad application prospects.

    Food Science & Technology
    YANG Yange, WU Zhanwen, LIU Tong, et al
    2025, 53(4):  135-146.  doi:10.12141/j.issn.1000-565X.240169
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    Meat is rich in nutrients and easy to breed microorganisms. Even at low temperatures, many microorganisms remain active and retain some virulence, so it is still necessary to screen for pathogens. In this study, a triple fluorescence ERA method was developed for the first time to detect Staphylococcus aureus, Salmonella and Listeria monocytogenes in meat products based on enzymatic recombinase amplification (ERA) technique. After optimization, the method could complete the simultaneous detection of three pathogens within 12 min. From DNA extraction to ERA detection, the whole detection process only takes 30 min, with the minimum detection limit of 10-2 ng/μL. The results of artificial pollution simulation showed that the method could detect three pathogens at the same time after the meat samples with 1 CFU/mL of pollution were cultured for 6 hours. The results of commercially available refrigerated meat products showed that the detection rate of three pathogens was between 6.45% and 19.35%, which was consistent with the detection results of the real-time PCR method of SN/T1870—2016. It was confirmed that the method established in this study has high accuracy and feasibility. This study will help reduce the potential disease caused by foodborne pathogens, and lays a certain foundation for on-site rapid detection of foodborne pathogens in the future.

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