Advances in Engineering Research : Possibilities and Challenges
Advances in Engineering Research : Possibilities and Challenges ISSN Print: 3079-5192 ISSN Online: 3079-5206
Heuristic-Based Decision Models for Complex System Classification: From Tourism to Healthcare
Classification in complex systems is not merely a technical or statistical task, but a managerial decision process shaped by uncertainty, high-dimensional information, and institutional constraints. This study conceptualizes classification as a form of heuristic decision-making embedded within complex systems, drawing on theories of bounded rationality, complex adaptive systems, and decision support systems. By comparing tourism management and healthcare governance, the research demonstrates that destination categorization, tourist segmentation, and disease risk stratification share the same structural decision challenges, including information overload, nonlinearity, time pressure, and stakeholder conflicts. Heuristic-based models such as genetic algorithms, ant colony optimization, particle swarm optimization, and rule-based decision rules are examined not as computational tools, but as managerial mechanisms that simplify complexity, enhance interpretability, and support timely action. Using real and verifiable datasets from global tourism and public health systems, the study evaluates classification performance through decision quality indicators, including reliability, stability, interpretability, and governance usability rather than domain-specific accuracy metrics. The findings confirm that heuristic classification models provide robust, transparent, and actionable support for policy modeling, resource planning, and institutional coordination across domains. Healthcare is therefore positioned as an application context rather than a defining research identity. The core contribution lies in establishing heuristic classification as a transferable management science methodology for complex system decision support.
Copyright (c) 2026 by author(s) and Erytis Publishing Limited https://creativecommons.org/licenses/by-sa/4.0
Adaptive and Scalable Electronic Instrument RDTU System
Traditional water meter monitoring systems have obvious drawbacks including low data acquisition efficiency, delayed equipment status monitoring and high operation and maintenance costs. This paper designs and implements an intelligent water meter monitoring system based on open-source Data Transfer Unit (DTU) and Modbus RTU protocol, which solves the pain points of manual meter reading and closed commercial DTU deployment in smart water supply scenarios. The front-end visual platform is developed with Vue 3 and Element Plus, while the back-end takes Python as the core development language, following standardized coding specifications defined in PEP 8. The system integrates PySerial serial communication, Modbus RTU message parsing, Redis memory cache and MySQL persistent database, forming a closed-loop data collection and management architecture of "DTU—Business Platform—Frontend Display", which conforms to the layered industrial IoT monitoring platform design paradigm. This paper focuses on developing core functions including plug-and-play protocol bridging for DTU, three-level cache scheduling, incremental data synchronization and Role-Based Access Control (RBAC) permission management scheme. Compatible with RS232 and CAN multi-channel communication interfaces, the system features high concurrency, low latency and strong scalability. It can be deployed in various smart water supply scenarios and provides a complete engineering transformation scheme for intelligent upgrading of stock metering equipment in Industrial Internet of Things (IIoT).
Fully Automatic PLC-Based Ice Pack Packaging Machine
Most ice pack packaging machines currently in production suffer from poor human-machine interaction, low production efficiency, and insufficient op-erational sensitivity, making them unable to meet the demands of the growing market. To address these issues, this paper proposes an ice pack packaging machine with a PLC as the core of the electrical control system. Buttons, encoders, and a touchscreen serve as input devices, while actuators include frequency converters, servo controllers, relays, and solenoid valves. Practical application demonstrates that this packaging machine significantly improves both production efficiency and safety, and effectively meets the production needs of the large-scale market.
Research on Stop-Addition Capability and Critical Distance of High-Speed Railway Trains under Speed-Up Conditions
To evaluate the feasibility of adding intermediate stops to high-speed railway trains under speed-up conditions, this paper takes a 300 km/h non-stop operation as the benchmark and investigates whether the running-time margin produced by increasing the operating speed to 350 km/h or 380 km/h can compensate for the time cost of added stops. Based on the acceleration, cruising, braking and station-stop processes of high-speed trains, evaluation indices are established, including speed-up time saving, stop-addition time cost, residual time margin, maximum feasible number of added stops and critical distance. The results show that the time cost of one added stop is much larger than the loss caused by speed-reduced pass-through at small and medium stations. Under 350 km/h and 380 km/h conditions, the total time cost of one added stop is approximately 282.04 s and 295.93 s, respectively, whereas passing through one station at 0.9 times the target speed increases the running time by only about 2.53 s and 2.60 s. The calculated critical distances for adding 1-4 stops are 178.06 km, 342.59 km, 507.12 km and 671.65 km under 350 km/h, and 131.97 km, 248.90 km, 366.20 km and 483.13 km under 380 km/h. The proposed evaluation method can provide a reference for stop-addition capability assessment and critical-distance determination under high-speed railway speed-up conditions.
Energy Consumption and Running Time Estimation for Train Section Speed Limit Based on Python Simulation
Speed-limited operation is a common scenario in high-speed rail line maintenance and emergency response to unexpected conditions. Under such constraints, fluctuations in train energy consumption and deviations in travel time directly affect the balance between energy efficiency and punctual operations, significantly influencing the quality and efficiency of railway transportation. To investigate the patterns of energy consumption and travel time under various speed-limiting scenarios and achieve optimal coordination between energy efficiency and on-time performance, this study establishes a simulation model for calculating high-speed train energy consumption and travel duration using Python as the platform and PyCharm as the development environment.This research clarifies the matching patterns between energy consumption and punctuality under multiple operating conditions, providing data support and theoretical reference for optimizing energy-efficient and punctual operations and refining operational planning under speed restrictions.
Study on the Construction and Operation Management of Urban Drainage Systems in the Alpine Plateau Region of Tibet
The construction and operation management of urban drainage systems in the alpine plateau region of Tibet face numerous unique challenges due to natural conditions such as high altitude, low temperatures, and frequent freeze–thaw cycles. This study systematically investigates the current status, existing problems, and underlying causes of urban drainage system development in Tibet through methods including field surveys, problem identification, operational failure analysis, and whole-process management evaluation. The results indicate that although the drainage network coverage rate in some central urban areas has exceeded 80%, it remains below 60% in certain counties and townships. In most towns, the temperature impact coefficient is lower than 0.4, while low temperatures, freeze–thaw cycles, and hypoxic conditions associated with high altitudes are identified as the primary factors affecting drainage system performance. Operational failures exhibit a cascading mechanism characterized by “pipeline freezing and structural deterioration → reduced conveyance capacity → increased equipment loading → declining treatment efficiency → overall system failure.” To address these challenges, an integrated construction and operation management framework consisting of “engineering optimization, operational reliability enhancement, intelligent operation and maintenance management, and institutional and policy support” is proposed. This study establishes a problem identification system and a whole-process management evaluation framework for drainage systems in the alpine plateau region of Tibet, providing a useful reference for the construction and operation management of drainage infrastructure in similar cold and high-altitude regions.
A Survey on Text-to-Image Person Re-identification: From CLIP to Fine-Grained Cross-Modal Alignment
Text-to-image person re-identification (TI-ReID) has become a critical task in intelligent surveillance, aiming to retrieve a target pedestrian from a large image gallery using a natural language description. Unlike image-based ReID, TI-ReID must bridge the semantic gap between modalities while capturing fine-grained, identity-discriminative details. The advent of Vision-Language Pre-training (VLP) models, particularly CLIP, has significantly advanced the field by providing robust pre-trained cross-modal representations. However, directly applying CLIP to TI-ReID is suboptimal due to a granularity gap: CLIP is effective at global scene-level matching, whereas TI-ReID demands fine-grained alignment of attributes like clothing, accessories, and actions. This survey systematically reviews the evolution of TI-ReID, from early unimodal backbone approaches to modern CLIP-based frameworks. We categorize existing methods into three main paradigms: 1) global feature learning with contrastive objectives, 2) part-level alignment using spatial attention or human parsers, and 3) token-level interaction and selection mechanisms. We analyze the core challenges of visual token redundancy, weak part-level correspondence, and noisy cross-modal data. Key representative methods such as IRRA, CFine, RASA, and RDE are discussed. Finally, we identify key open challenges and outline promising future directions, including multimodal large language models, query-aware alignment, and video-based ReID.
Mechanical Properties and Acoustic Emission Damage Evolution of Sandy Mudstone Under Gradient Confining Pressures
To reveal the macroscopic deformation failure and microscopic damage evolution mechanisms of sandy mudstone under deep high in-situ stress environments, triaxial compression tests were conducted under seven gradient confining pressures (0, 2, 4, 6, 8, 10, 15 MPa), and acoustic emission (AE) signals were monitored synchronously. The effects of confining pressure on the stress-strain characteristics, strength-deformation parameters, energy evolution, macroscopic failure modes, and AE damage laws of sandy mudstone were systematically analyzed. The results show that with increasing confining pressure, the compaction stage of the stress-strain curve disappears, the plastic stage prolongs, and the post-peak attenuation slows down, presenting a transition from brittle to ductile failure. The peak strength increases linearly with confining pressure, with a cohesion of 9.44 MPa and an internal friction angle of 29.44° fitted by the Mohr-Coulomb criterion. At low confining pressure, dissipated energy mainly drives tensile crack initiation, while at high confining pressure, it dominates shear crack development. AE activity is highly coupled with stress stages, and the cumulative ringing count reaches a peak at 10 MPa. The peak damage value decreases from 0.52 at 2 MPa to 0.12 at 15 MPa, indicating that confining pressure significantly inhibits damage accumulation. This study provides an experimental and theoretical basis for stability control of deep soft rock roadways.
Copyright (c) 2026 by author(s) and Erytis Publishing Limited. https://creativecommons.org/licenses/by/4.0/
A Hierarchical Free Energy Framework for Ranking CDK Inhibitors: From PMF Barriers to Alchemical Precision
Accurate prediction of binding free energies for structurally homologous kinase targets remains one of the most challenging tasks in computational drug discovery. CDK1 and CDK2 provide an exceptionally stringent benchmark: their active sites differ by only 0.72 Å backbone RMSD, yet experimental ITC data reveal up to 170-fold selectivity differences for certain inhibitors, corresponding to a ΔΔG of only 2.87 kcal/mol, which is smaller than the typical error of most computational methods. Here we establish and validate a three-tier hierarchical free energy protocol applied to five CDK–inhibitor complexes (Dinaciclib, AZD5438, and CGP74514A bound to CDK1 and CDK2). Tier 1 (MM/PBSA endpoint calculations) achieves a qualitative affinity ranking but fails quantitatively, yielding R ≈ 0.45 and a critical rank inversion for CDK2-Dinaciclib. Tier 2 (umbrella sampling with 56 harmonically restrained windows and WHAM reconstruction) correctly identifies the primary free energy barrier to dissociation in the 6-12 Å center-of-mass distance regime and correctly rank-orders all complexes, though absolute values are systematically underestimated. Tier 3 (alchemical double-decoupling via 62 λ-states with thermodynamic integration and MBAR cross-validation converged to within 0.2 kcal/mol) achieves near-chemical accuracy with a mean absolute error of ~1.11 kcal/mol and R ≈ 1.0.
Study on Route Alignment Adjustment and Optimization of Existing Road Resource Utilization in Highway Reconstruction and Expansion Projects
This study develops a collaborative optimization framework for highway reconstruction and expansion that integrates “alignment adjustment–existing road utilization–functional improvement.” An evaluation indicator system is established to assess the utilization value of existing road resources, covering geometric alignment resources, structural resources, land-use resources, traffic organization, economic benefits, and environmental benefits. The weights of the indicators are determined by combining the analytic hierarchy process and the entropy weight method. On this basis, a multi-objective alignment optimization model is proposed, incorporating engineering cost, traffic safety, existing road utilization, ecological impact, and life-cycle carbon emissions, and the model is solved using the NSGA-II algorithm. A reconstruction and expansion project of a mountainous Class II highway in Tibet is taken as a case study for verification. The results show that the comprehensive coordination scheme achieves the lowest comprehensive evaluation value of 0.28 under the conditions of an existing road utilization rate of 64.2%, a safety risk index of 0.31, and carbon emissions of 118,000 t, outperforming both the existing-road-priority scheme and the alignment-improvement-priority scheme. The findings indicate that embedding the value assessment of existing road resources into the entire process of alignment adjustment can effectively improve the scientific basis of alignment decision-making, enhance resource utilization efficiency, and promote green and low-carbon development in highway reconstruction and expansion projects. This study provides methodological support for optimizing highway reconstruction and expansion schemes under complex constraints.
Whole-genome sequencing analysis of imported SARS-CoV-2 cases at Hangzhou Port
This study employed the Nanopore nanopore sequencing platform and the Baiyi whole-genome analysis software to perform whole-genome sequencing on 50 imported COVID-19 cases collected at the Hangzhou port from September 2022 to January 2023, analyzing the distribution of viral variants to provide theoretical support and practical guidance for epidemic prevention and control. A total of 50 complete SARS-CoV-2 genome sequences were obtained, with 46 cases exhibiting sequence coverage exceeding 99%. All Pangolin phylogenetic analyses identified the variants as Omicron strains, consistent with the globally dominant variant. The distribution of these variants in the functional gene regions may influence the virus's infectivity, pathogenicity, and other biological characteristics. This study holds significant implications for COVID-19 prevention and control at the Hangzhou port and nationwide, offering theoretical support and practical guidance for optimizing detection protocols and enhancing flight controls in high-risk areas.
Mechanisms of Early Cracking in Concrete Structures in Cold Regions and On-Site Construction Control Techniques
Early-age cracking in concrete structures during winter construction has become increasingly prominent, seriously affecting structural durability and engineering safety. This study focuses on concrete structures in cold regions and systematically investigates the mechanisms of early-age cracking and on-site construction control techniques through theoretical analysis, construction technology research, and engineering applications. The research methodology includes the design of casting temperature and thermal insulation construction techniques, the establishment of a temperature control index system, dynamic evaluation of crack risk coefficients, and validation through projects in high-cold regions. Results indicate that concrete cracking in cold areas primarily results from the combined effects of thermal stress, shrinkage deformation, frost heave, and construction factors. Key control indicators include casting temperature, internal peak temperature, internal-external temperature differential, and cooling rate. The integrated application of heat storage insulation, electric heating, moisture-maintaining curing, and intelligent temperature control effectively reduces the number of cracks. By combining temperature monitoring with crack risk coefficients, dynamic closed-loop control during construction can significantly reduce early-age cracking. The proposed temperature control index system and dynamic crack management method systematically reveal the laws governing early-age cracking in concrete in cold regions and provide practical technical guidance for concrete construction in high-cold areas, offering important theoretical and engineering significance.
Feasibility and Challenges of Ultrafine Stone Powder and Fly Ash Composite Grouting Material
Coal mining and coal-fired power generation produce large quantities of coal-based solid wastes such as fly ash and coal gangue, whose accumulation occupies land and poses environmental risks. Meanwhile, ultrafine stone powder, as a byproduct of stone processing, faces similar challenges in resource utilization. The combination of these two types of solid wastes to prepare grouting materials has become an important research direction in fields such as bed-separation grouting for subsidence reduction and goaf filling treatment. This paper systematically analyzes the feasibility basis of ultrafine stone powder and fly ash composite grouting material, including the strong impetus from national policies on solid waste resource utilization, significant reduction in raw material costs, and the complementary performance advantages of the composite system in terms of fluidity regulation, stability improvement, and strength enhancement. At the same time, it deeply discusses the multiple challenges faced by this material, covering the difficulty of matching slurry rheological behavior with bed-separation space, the deterioration of filling quality caused by water separation, the risk of groundwater pollution from heavy metal leaching, and the precise matching between grouting timing and filling effectiveness. The research indicates that this composite material has broad prospects for engineering applications, but its large-scale promotion still requires continuous technical breakthroughs in formulation optimization, environmental risk control, and engineering adaptability.
Mechanisms and Control of Accumulated Plastic Deformation in Highway Subgrades for Durable Service
Under long-term cyclic traffic loading, subgrade soils may develop accumulated irrecoverable plastic strain, which gradually evolves into permanent deformation affecting pavement smoothness, bearing capacity, and durability. Compared with construction-stage compaction quality, permanent deformation of subgrades during operation can better reflect the long-term service risks of road structures under coupled loading–environmental effects. This paper systematically reviews the testing and characterization, influencing factors, prediction models, structural calculation methods, and control approaches for subgrade permanent deformation. The results indicate that water content, degree of compaction, cyclic stress, confining pressure, loading duration, rest period, and overburden static load jointly govern the development of permanent deformation. Existing constitutive models have a solid theoretical basis but are limited by computational efficiency in long-term cyclic analysis, whereas mechanical–empirical models are convenient for engineering applications but still face limitations in parameter calibration and generalization capability. Future research should strengthen the reproduction of service conditions, coupled moisture-field and stress-field analysis, and reliability-based control criteria, thereby providing a basis for durable subgrade design and maintenance decision-making.
Comparative Analysis on Mechanical Performance of Concrete Inclined Tension Rods with Square and Circular Steel Pipes in Cable-Stay Girder Anchorage Zone of Low-Pylon Cable-Stayed Bridge
Aiming at the inherent performance bottlenecks of reinforced concrete (RC) inclined tension rods in the cable-girder anchorage zone of low-pylon cable-stayed bridges, such as low ductility and significant post-peak damage localization, an optimized scheme of prestressed concrete-filled steel tube (CFST) inclined tension rod is proposed. Taking the Luzhou Tuojiang Railway Super Large Bridge, a low-pylon cable-stayed bridge with a span arrangement of (146+292+146) m, as the engineering background, a three-dimensional nonlinear finite element model is established based on ANSYS APDL. The whole-process mechanical behaviors of three schemes, namely RC, square CFST and circular CFST inclined tension rods, under the most unfavorable cable force are comparatively analyzed, and the influence law of section form on mechanical performance is revealed from the perspective of confinement mechanism. The results show that compared with the RC scheme, the ultimate bearing capacity of the two CFST schemes is increased by 115.3% and 124.2%, the initial secant stiffness is increased by 61.9% and 63.2%, and the displacement ductility coefficient is increased by 33.5% and 49.4%, respectively. The uniform circumferential confinement provided by the circular section completely eliminates the weak confinement area at the mid-span of the square steel tube wall, and the load rises steadily at the large deformation stage. The circular CFST scheme with a diameter of 560 mm, wall thickness of 16 mm, Q345 steel tube, C60 core concrete and confinement coefficient ξ=0.829 is recommended as the optimal design scheme. The research results can provide a reference for the engineering design of inclined tension rods in the cable-girder anchorage zone of low-pylon cable-stayed bridges.
The Rheological Properties of Recycled Asphalt With Pyrolysis Oil From Waste Plastics
To understand the regeneration effects of PEO and PPO regenerants on aged asphalt, this chapter studies the physical properties of the regenerated asphalt and finds that PEO and PPO can basically restore the performance of aged asphalt, but the improvement effects of PEO and PPO on base asphalt and SBS modified asphalt are different.
Research and Field Application of a Down-Dip Withdrawal Method for Heavy Fully Mechanized Hydraulic Supports in a Steeply Inclined Longwall Face
The down-dip withdrawal of heavy hydraulic supports under a large face inclination remains a bottleneck affecting the safety and efficiency of longwall face relocation. In this study, a down-dip withdrawal technology for heavy fully mechanized hydraulic supports was developed and field-tested at the 2091 working face of No. 6 Coal Mine, Hebi Coal Company. The coal-pillar layout during the closing stage was optimized to improve the coal recovery ratio and reduce resource losses. The pre-withdrawal support scheme, including a flexible-mesh artificial roof, was redesigned to enhance roof stability during the withdrawal period. The withdrawal process was also optimized to enable parallel operations of support alignment, loading and disassembly. Mechanized withdrawal equipment was introduced to address the anti-overturning and anti-sliding requirements during top-to-bottom transportation of fully mechanized supports, thereby realizing safe and mechanized support withdrawal. Field application showed that the face relocation time was reduced by 55%, while labor intensity, production cost and the risk of spontaneous combustion were substantially decreased.
Retrieval of heavy supports in coal mines
Research Progress on Dowel-Type Connection Joints of Timber Structure
Dowel-type connections (bolts, dowels, self-tapping screws, etc.) are the most widely used joint forms in modern timber structures, and their mechanical properties directly affect the load-carrying capacity and deformation behavior of the overall structure. This paper reviews the research progress of dowel-type timber connections from three aspects: load-carrying capacity calculation theory, numerical simulation methods, and innovative connection technologies with durability issues. In terms of load-carrying capacity theory, the Johansen yield model remains the core foundation of various design codes. Recent studies have extended this model to new engineered wood products such as cross-laminated timber and glued laminated bamboo, as well as to extreme conditions like fire. Regarding numerical simulation, the classical finite element method is the most mature approach, while the peridynamics method shows unique advantages in simulating wood cracking and fracture. For innovative technologies, self-tapping screw reinforcement and all-wood connections (dowel laminated timber, rotational welding, etc.) have become important development directions, but the water resistance of rotationally welded joints remains a critical issue. Current research still has gaps in the load redistribution mechanism of multiple-dowel connections and long-term performance under complex environmental conditions. This review aims to provide a reference for the design optimization and future research of dowel-type timber connections.
Adaptive Terrain-Cognizant Multispectral Vision and Distributed Intelligence for Low-Altitude Unmanned Systems in Yunnan Plateau and Canyon Ecosystems
The rapid expansion of the low-altitude economy across southwestern China necessitates autonomous unmanned aerial systems capable of sustained operations within deeply dissected topography and hyperdiverse ecosystems. This study presents a unified framework, designated LAVENS, that integrates terrain-cognizant adaptive visual odometry with hierarchical spectral attention networks to simultaneously address navigation robustness and ecological inference accuracy in complex Yunnan terrains. A terrain roughness adaptive factor is embedded within an extended Kalman filtering pipeline to modulate measurement noise covariance in real time, thereby mitigating scale drift during canyon traversal. Complementarily, a hierarchical spectral attention network processes ten-band multispectral tensors through scaled dot-product self-attention to resolve vegetation boundaries under heterogeneous canopy illumination. Edge-cloud orchestration, based on directed acyclic graph scheduling, ensures end-to-end latency remains below 150 milliseconds while conforming to low-altitude airspace traffic management protocols. Extensive validation spanning six altitudinal belts—from tropical rainforest to nival rock—demonstrates that the proposed methodology reduces absolute trajectory error by a mean of 41.3 percent relative to current open-source SLAM libraries, and improves mean intersection-over-union for canopy species segmentation by 18.7 percent over conventional encoder-decoder architectures. These findings establish a scalable software and hardware architecture for ecological logistics and infrastructure inspection within the low-altitude economic corridor of the Yunnan plateau.
Research Progress on Hydration Heat of Mass Concrete
Mass concrete is widely used in bridge pile caps, hydraulic structures, foundations of high-rise buildings, nuclear power projects, and large underground structures. Due to the large structural dimensions, the hydration heat generated inside concrete is difficult to dissipate rapidly, which often leads to a high early-age temperature rise and significant temperature difference between the interior and surface. When thermal deformation is restrained, thermal stress develops inside the structure. If the tensile thermal stress exceeds the early-age tensile strength of concrete, temperature cracks may occur, thereby affecting structural integrity, durability, and service safety. Based on previous studies, this paper reviews the research progress on hydration heat of mass concrete from the aspects of hydration heat mechanism, material and mix proportion control, construction temperature-control measures, temperature monitoring, and numerical simulation. Existing studies show that reducing the hydration heat of cementitious materials, optimizing the proportion of mineral admixtures, controlling placing temperature, adopting layered and block construction, strengthening thermal insulation and moisture curing, and using cooling pipes can effectively reduce peak temperature and internal-surface temperature difference. With the development of monitoring technologies and numerical methods, temperature control of mass concrete is gradually moving toward refinement, intelligence, and whole-process control..
Study on Multi-parameter Mechanical and Microstructural Characteristics of Mining-used Cement-based Grouting Materials
To investigate the reinforcement effects of two grouting materials, laboratory tests were conducted using ordinary Portland cement and ultra-fine cement as the test materials. Taking the consolidated bodies of cement-based grouts as the research objects, tests on slurry flow characteristics, uniaxial compressive tests on consolidated bodies, and scanning electron microscopy (SEM) tests were carried out to study the mechanical properties of cement-based grout consolidated bodies with different water-cement ratios. The test results show that the viscosity of ordinary cement-based grout decreases with the increase of water-cement ratio, while the bleeding rate increases accordingly. The uniaxial compressive strength of ordinary cement-based consolidated bodies decreased by 35.1%, 43.9% and 5.2% respectively with the increase of water-cement ratio. Meanwhile, the average cumulative acoustic emission ring counts of ordinary cement-based consolidated bodies decreased by 76.7%, 71.1% and 50.1% respectively with the increase of water-cement ratio. Compared with ordinary cement grout at the water-cement ratio of 1:1, ultra-fine cement grout has lower viscosity and bleeding rate, and its consolidated body exhibits higher uniaxial compressive strength and larger cumulative ring counts. Analysis of SEM micrographs reveals that the ultra-fine cement consolidated body has fewer internal defects, more stable structure and stronger bearing capacity. The above test results indicate that ultra-fine cement can achieve significantly better reinforcement performance as a grouting material than ordinary Portland cement.
Mechanical Properties of Consolidated Bodies
Research Progress on the Seismic Behavior of Steel-Connected Precast Concrete Beam-Column Joint
Precast concrete frame structures have attracted increasing attention because they can improve construction efficiency, reduce on-site wet work, and support industrialized building production. In seismic regions, however, the reliability of beam-column connections remains a key factor controlling the load-transfer mechanism, deformation capacity, energy dissipation, and post-earthquake safety of the structural system. Steel-connected precast concrete beam-column joints introduce steel components into the joint region or beam-end connection zone, thereby changing the stiffness distribution, damage evolution, and hysteretic behavior of conventional precast joints. Based on existing studies, this paper reviews the research progress on precast concrete beam-column joints, steel-concrete composite beam-column joints, finite element simulation, and restoring-force models. The results show that considerable progress has been made in experimental investigation, connection-detail optimization, parameter analysis, and hysteretic model development. Properly designed precast and steel-concrete composite joints can achieve satisfactory bearing capacity, ductility, and energy dissipation, while numerical methods provide an effective means for extending limited test results to broader parameter ranges. Nevertheless, research specifically focused on steel-connected precast concrete beam-column joints remains insufficient, especially regarding low-cycle reversed loading behavior, unified design methods, and restoring-force models consistent with their actual damage mechanism. Future studies should strengthen full-scale cyclic tests, refined numerical modeling, and frame-level seismic performance evaluation.
Research Progress on the Seismic Behavior of Weak-Axis Beam-to-Column Connections of H-Shaped Steel Columns
Weak-axis beam-to-column connections of H-shaped steel columns are important force-transferring components in steel frame structures, and their mechanical behavior directly affects structural load-carrying capacity, deformation capacity, and seismic safety. Compared with strong-axis connections, weak-axis connections mainly transfer beam-end moments through the column web and its adjacent region. Owing to the relatively low out-of-plane stiffness of the column web and insufficient restraint of the panel zone, these connections are prone to local deformation, stress concentration, insufficient rotational stiffness, and uncertain plastic development. With the development of prefabricated steel structures and low- to mid-rise steel residential buildings, the seismic behavior of weak-axis connections has attracted increasing attention. This paper reviews existing studies from the aspects of experimental research, finite element analysis, moment-rotation relationship models, and new connection configurations. Previous studies show that end plates, T-shaped connectors, U-shaped connectors, I-shaped plates, column-tree splices, reduced beam sections, and local strengthening measures can improve load-transfer paths, enhance rotational stiffness and energy dissipation capacity, and move plastic deformation away from the column face. However, unified design methods, restoring force models, and prefabricated details still require further investigation.
Research on Surface Deformation Monitoring and Stability of Mined-out Areas Based on SBAS InSAR Technology
Long-term surface deformation over old mined-out areas overlain by thick unconsolidated strata in North China is prominent. Traditional monitoring approaches are difficult to achieve large scale, long time series, and high precision dynamic observations. To scientifically understand the spatiotemporal evolution of surface subsidence and site stability characteristics of old mined out areas, this paper takes the mined out areas of Panels 2301, 2302, and 2303 in the No.5 Coal Mine of Hebi Mining Group, Shancheng District, Hebi, Henan Province as the study object. Using the SBAS InSAR time series interferometric technique, 110 scenes of Sentinel 1A images from November 2015 to December 2024, combined with 30 m resolution SRTM DEM data and ESA precise orbit data, are adopted to invert the spatiotemporal distribution of annual average surface deformation rate and cumulative deformation over the past decade. Through time series subsidence curve analysis of typical monitoring points, profile comparison, and accuracy verification, the staged evolution and spatial differentiation of surface subsidence above goafs under thick unconsolidated strata are revealed. The results show that the study area is dominated by surface subsidence, with a maximum subsidence rate of −36 mm/a and an average rate of 2.35 mm/a. The spatial pattern of subsidence exhibits an obvious funnel shaped stepwise decrease. Around 2018, surface subsidence in the study area generally shifted from the rapid development stage to the residual deformation stage with slow attenuation. The attenuation rate shows significant spatial differences controlled by fault locations, panel conditions, and geological structures. Panel 2303, with a later stopping time, shows the most active subsidence, while Panels 2301 and 2302, mined earlier, have become basically stable. The SBAS InSAR results agree well with leveling measurements, and the monitoring accuracy meets the requirements for goaf stability evaluation. The findings can provide reliable technical support and scientific basis for land redevelopment, construction site selection, geological hazard risk assessment, and long term safety monitoring of old mined out areas in the Hebi mining area
Recent Advances in Quantitative Sensitivity Analysis for Dynamic Construction Control of Prefabricated Steel-Concrete Composite Cable-Stayed Bridges
Prefabricated steel–concrete composite cable-stayed bridges are a major form of industrialized bridge construction. Dynamic construction control and parameter sensitivity quantification are critical to ensuring structural safety and final alignment. Ultra-high-performance concrete (UHPC) has become a preferred material for precast segment connections due to its superior bond performance with reinforcing bars. This paper reviews recent advances in quantitative sensitivity analysis for dynamic construction control, focusing on the bond behavior of lap-spliced rebars in UHPC, key influencing parameters, and time-varying sensitivity characteristics. Research shows that steel fiber content, rebar diameter, lap length, cover thickness, and transverse reinforcement dominate bond strength and system sensitivity. The bond stress distribution along lap length varies significantly under different configurations, directly affecting structural stability during construction. Finally, existing challenges and future research needs are briefly discussed.
Prefabricated Steel–Concrete Composite Cable-Stayed Bridge
Research Progress on Fatigue Performance of Steel-Concrete Composite Structures
Steel-concrete composite structures integrate the superior tensile properties of steel and excellent compressive performance of concrete, which have been widely applied in long-span bridges, high-rise buildings, and industrial structures. Fatigue performance is one of the core control indicators for composite structures serving under long-term cyclic loads, such as vehicle traffic, wind excitation, and mechanical vibration. This paper systematically sorts out the latest research progress on the fatigue performance of steel-concrete composite structures in recent years. Firstly, the fatigue damage evolution mechanism of composite systems, including constituent materials and steel-concrete interface, is elaborated. Subsequently, the state-of-the-art experimental and numerical research on the fatigue behavior of typical composite members and key connectors is summarized. Then, the critical influencing factors, including material properties, structural details, service environment, and load characteristics, are comprehensively analyzed. Furthermore, the mainstream fatigue life evaluation methods and theoretical models are classified and discussed. Finally, the existing limitations of current research are pointed out, and the future research directions are prospected, aiming to provide reference for subsequent academic research and engineering application of steel-concrete composite structures.
State of the Art of Steel-Concrete Composite Bridge Towers with Steel Shells
As a high-performance steel-concrete composite structure, the steel shell concrete bridge tower integrates the advantages of high bearing capacity, excellent seismic performance, rapid construction and outstanding durability, and has become the mainstream structural form of bridge towers for long-span bridges in recent years. This paper systematically reviews the latest research progress of steel shell concrete bridge towers. Firstly, it summarizes the typical structural forms and construction technologies, and classifies the main failure modes under mechanical loads and thermal loads. Subsequently, it systematically discusses the influence laws of key parameters such as steel shell thickness, concrete strength, steel ratio, stud spacing and temperature field on the mechanical properties and interfacial bonding performance of the structure. Meanwhile, it sorts out the research status of thermal effects and long-term performance of steel shell concrete bridge towers. Existing studies show that the axial and eccentric compressive bearing capacity of the structure increases with the rise of steel ratio and concrete strength; reasonable stiffener configurations and shear connectors can significantly improve the interfacial bonding performance and inhibit crack propagation. The temperature field has a remarkable impact on the thermal stress of steel shell concrete tower columns, and hydration heat and solar radiation are the core control factors. Finally, this paper points out the deficiencies of existing research and prospects the future research directions including multi-field coupling theory, refined design method and prefabricated construction technology, so as to provide a reference for the engineering design and application of this structure.
Analysis of Functionalized Mode of Urban Building Facade Lighting
Le Corbusier once said, "Architecture is the brilliant, correct, and clever performance of assembled blocks under light, and the task of an architect is to bring the surface wrapped around the blocks to life." Architectural light is precisely one of the indispensable elements that "bring the surface to life.". The purposefulness and regularity of urban building facade lighting should be based on its functional use. As a functional lighting method, light transmission within buildings represents the aesthetic subject's recreation of the aesthetic object. It is also an important indicator for measuring the quality of urban buildings.
Engineering Biomimetic and Multifunctional Artificial Periosteum via Electrospinning for Bone Regeneration
This review delves into the advancements and strategies in electrospinning for the development of artificial periosteum in bone regeneration. Electrospun nanofibers offer advantages such as high surface area, porosity, and multifunctionality, making them suitable for mimicking the natural periosteum. The focus of this review lies in the recent progress in crafting electrospun artificial periosteum. It elucidates the histological structure and function of the periosteum, emphasizing its pivotal role in bone repair. Various materials, encompassing natural and synthetic polymers, are scrutinized for the design of effective artificial periosteum. Furthermore, it explores the utilization of diverse electrospinning process and other technologies such as phase separation and sol-gel method, which can be amalgamated with electrospinning for artificial periosteum development. Additionally, it delves into synergistic regulation of multidimensional osteogenic cues and the crucial osteogenic-angiogenic coupling effect for bone healing. In conclusion, limitations of current techniques and strategies are outlined, alongside future prospects for the application of advanced electrospinning technologies in the preparation of artificial periosteum.
Improved YOLOv11-Based Algorithm for Wood Surface Defect Detection
Wood surface defect detection is a critical process in industrial quality control. However, conventional deep learning models often struggle with complex periodic wood grain interference, extreme scale variations between micro-defects and large defects, and irregular defect geometries. To address these challenges, this paper proposes WSD-YOLO, an improved object detection algorithm based on YOLOv11n. First, an Enhanced Backbone (EB) is constructed by deepening the C3k2 modules to enrich multi-level feature representations, which improves the network's capacity to extract complex defect patterns. Second, a Transformer Attention Block (TAB) with an 8-head multi-head self-attention mechanism is integrated to model long-range spatial dependencies, effectively suppressing background texture interference from wood grains. Third, a BiFPN with P2 Enhancement (BPE) extends the feature fusion network to a four-scale bidirectional architecture, utilizing a high-resolution P2 branch (stride 4) to capture fine spatial details of micro-defects such as cracks and resin spots. Finally, a Decoupled Multi-Scale Head (DMH) separates the classification and localization branches to alleviate optimization conflicts caused by irregular defect boundaries. Experimental results on a custom dataset of 4,000 images across 7 defect categories demonstrate that WSD-YOLO achieves an mAP@0.5 of 74.34% and an mAP@0.5:0.95 of 39.24%, outperforming the YOLOv11n baseline by 0.82% and 1.51%, respectively. Notably, the detection precision reaches 72.18%, a 3.39% improvement over the baseline, confirming the model's superior capability in reducing false positives in complex industrial environments.