The WSRJ is an international peer reviewed, online and print version journal published by Boya Century Publishing. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of science and technology. We bring together Scientists, Field Engineers, Scholars and Students of related fields. WSRJ is a monthly, open access, peer reviewed and fully refereed international journal with minimal processing charge.
Research on the Performance of SiC Particle Reinforced Aluminum Matrix Composite Brake Discs
To meet the performance requirements of wear resistance, energy saving and consumption reduction during operation, as well as speed and noise reduction for rail transit brake discs, a SiCp/A356 composite material with a SiC particle volume fraction of 20% was prepared by liquid stirring casting method using SiC particles as reinforcement and A356 aluminum alloy as matrix. Firstly, experiments were conducted on the thermal cycling characteristics, crack propagation, and fracture performance of the high-speed train brake disc made of this material. Secondly, a brake disc model was established using HYPERMESH software. Then, finite element simulation analysis of the temperature and stress fields under emergency braking conditions at 200km/h was conducted using ANSYS software to study the fracture failure mechanism. Compared with traditional steel brake discs, the results show that the maximum temperature during the braking process of SiCp/A356 reinforced aluminum based composite brake discs is reduced by 29.6% compared to ordinary steel materials; The amplitude of stress changes is small, which can effectively reduce thermal damage to the surface of the brake disc; The fatigue life is increased by about 20% compared to ordinary steel materials, exhibiting excellent mechanical and fatigue properties.
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Research on Curvature Adaptive Control Method for ABB Robot Blade Polishing Residuals
To address challenges in traditional blade polishing such as low error control precision, irrational path planning, and poor parameter matching of belt pulleys, error control methods were investigated using ABB industrial robots as execution platforms and belt pulleys as polishing tools, combined with curvature adaptive algorithms. By analyzing blade surface curvature characteristics, a correlation model linking polishing errors to parameters and surface curvature was established. A curvature-adaptive error control algorithm was designed to dynamically adjust polishing parameters across different curvature zones. Simulation environments were built using Robot Studio platform to validate error control through both simulation and experimental testing. Results demonstrate that: In high-curvature zones, polishing errors reach 0.012mm at 1500r/min belt speed and 80N polishing force; In medium-curvature zones, errors minimize to 0.009mm at 1700r/min belt speed and 70N force; In low-curvature zones, errors decrease to 0.007mm at 2000r/min belt speed and 60N force. The curvature-adaptive control strategy achieves an average error of 0.011mm and a maximum error of 0.021mm, both remaining within the target error range of 0.1mm. Compared to traditional fixed-parameter methods, this approach improves allowance control precision by 61.1%. These findings provide theoretical support and technical references for automated high-precision blade polishing.
Research and Practice on Meteorological Data Security Supervision Technology Based on Tianqing·Qinghai
To address the challenges of data circulation security supervision in the meteorological big data environment and enhance the security protection capabilities of meteorological data usage in Qinghai Province, this paper, based on the "Tianqing·Qinghai" meteorological big data cloud platform and the "Tianjing·Qinghai" comprehensive business monitoring system, adopts three core methods: data structure processing, data denoising, and data security usage auditing. It integrates advanced technologies such as distributed collection control, parallel computing, and big data storage to construct a meteorological data security supervision system. The research focuses on three dimensions: the development of meteorological data security supervision technology, analysis of usage situations, and security risk management. It establishes the judgment rules and disposal processes for six types of data security risk events, achieving real-time monitoring of account access behaviors, precise control of key accounts, and collaborative handling of risk events. Practical application shows that this system can effectively reduce data security risks, improve supervision efficiency, and provide a replicable technical solution and practical reference for data security governance in provincial meteorological departments.
Study on the Flow Field Characteristics of a Gas–Liquid–Solid Three-Phase Combined Impeller Agitator Based on CFD
To address the issues of mixing efficiency and impeller configuration in the gas–liquid–solid three-phase system during CO₂ mineralization and sequestration using coal-based solid waste, a numerical investigation of the internal flow characteristics in a three-phase stirred reactor was carried out using computational fluid dynamics (CFD). A reactor model was established using Fluent simulation software. The multiple reference frame (MRF) method was adopted to construct the stirring flow-field model, and the Navier–Stokes equations were employed as the governing equations. The standard k–ε turbulence model was applied to solve the fluid flow in the stirred tank. Under a stirring speed of 100 r/min, the flow-field characteristics of different impeller combination schemes were simulated and analyzed. By examining the axial, radial, and tangential velocity distributions at specific cross-sections of the reactor, and combining velocity contours with the distributions of solid volume fraction and gas volume fraction, the flow characteristics and mixing performance of different impeller combinations were comparatively studied. The results show that different impeller combinations have significant effects on the internal flow-field structure and multiphase distribution in the reactor. Among the investigated configurations, the combination of an upper double-helical ribbon impeller and a lower pitched-blade turbine impeller can generate a more pronounced axial circulation flow, promoting the suspension of solid particles and the dispersion of gas bubbles. This configuration results in a more uniform distribution of the three phases within the reactor and improves the overall mixing efficiency of the system. The findings provide a theoretical reference for the structural optimization of three-phase stirred reactors and the design of impeller combinations in the CO₂ mineralization and sequestration process using coal-based solid waste.
Double helical ribbon and three-pitched blade turbine combined impeller
Hardware-in-the-Loop Simulation of Pressure Measurement Modules in While-Drilling Systems
To address the issues of high cost and low efficiency in traditional testing of pressure measurement modules while drilling—which rely on physical sensors and simulated high-temperature environments—a testing system based on hardware-in-the-loop simulation technology is proposed to achieve efficient and low-cost performance verification of the measurement module. The system consists of a PC host computer, a real-time simulator (PXIe platform), and the measurement module. Simulation models of pressure and temperature sensors are built using Simulink and deployed to the real-time simulator via VeriStand software to emulate voltage and resistance signals consistent with those of actual sensors. A host computer interface is developed using C# to enable parameter configuration, data acquisition, and error analysis. The system validates the effectiveness of the temperature drift compensation algorithm through comparative experiments with and without correction. Test results show that the system can effectively simulate downhole sensor outputs, and after correction, the pressure measurement error is controlled within ±108 psi, significantly suppressing the influence of temperature on measurement accuracy. This verifies the feasibility and superiority of the hardware-in-the-loop simulation method in testing measurement-while-drilling modules.
Permanent Magnet Synchronous Motor Drive Control for High-Temperature Downhole Formation Sampling: Design and Experimental Validation
Downhole formation sampling requires stable motor control under high temperature and strong vibration. This paper presents an integrated permanent magnet synchronous motor (PMSM) control-drive system for a compact downhole sampling tool. The system combines miniaturized hardware, resolver-based feedback, field-oriented control, and an improved fuzzy two-degree-of-freedom PI speed controller to enhance low-speed stability and turn-count accuracy. Experiments were carried out under no-load, load, high-temperature, and vibration conditions. Results show that the system operates reliably at 150 °C and 20 g vibration, with steady-state speed error below 1% full scale and full-scale relative turn-count error below 0.5%. The proposed design provides a practical high-temperature motor-drive solution for downhole formation sampling tools.
Research on Ferromagnetic Resonance of Electromagnetic Voltage Transformers in Shale Gas Field Distribution Network
The shale gas field has vigorously implemented the "electricity replacing oil" extraction method. Promoting the wide application of distribution network automation technology in shale gas distribution networks. Regarding the frequent occurrence of ferromagnetic resonance faults caused by the saturation of electromagnetic voltage transformers. The current research fails to take into account the load characteristics and actual working conditions. This paper, based on the electromagnetic transient simulation software PSCAD, establishes a PT ferromagnetic resonance model for the 10kV non-grounded system of the Changning Shale Gas Field. The simulation analyzed the effects of line length, conductor cross-section and excitation conditions on ferromagnetic resonance, and proposed suppression measures for the PT high-voltage side through a linear resistor connection. The simulation results show that when the length of the line meets the resonance condition, an increase in length will lead to an increase in the amplitude and frequency of the resonant overvoltage. When considering the cross-sectional area of the electrical conductor, the overcurrent on the PT high-voltage side of the fracturing-specific line is greater than that of the conventional line, which is prone to causing the fuse to blow. The influence of excitation conditions on resonant overvoltage varies greatly. The resonant amplitude triggered by arc grounding faults is the highest. Finally, a protective measure is proposed where the neutral point of the primary winding of the PT is connected to a non-linear resistor, in order to prevent the frequent occurrence of resonance accidents.
a series of policies have been introduced
Rheological Characteristics and Engineering Predictive Modeling of Liquid CO₂/Guar Foam Fracturing Fluids
Although CO₂ foam fracturing fluids are partially heated by the formation during injection, the majority of the CO₂ phase remains in a liquid state along the wellbore. Therefore, investigating the rheological behavior of liquid CO₂ foam fracturing fluids is essential for accurate friction prediction and hydraulic parameter optimization. In this study, a high-precision rotational rheometer was employed to characterize the rheological properties of liquid CO₂/guar-based foam fracturing fluids under controlled temperature and pressure conditions. Compared with conventional large-scale pipe rheometers, the present method provides improved measurement accuracy, repeatability, lower experimental cost, and better variable control. Experimental results indicate that under high shear rate conditions (>30 s⁻¹), the power-law model adequately describes the flow behavior of the liquid CO₂/guar foam system, with a coefficient of determination (R²) greater than 0.996. The effects of CO₂ volume fraction, temperature, and pressure on the flow behavior index (n) and consistency coefficient (K) were systematically analyzed. An exponential temperature-dependent correlation model for rheological parameters was established, yielding an average prediction error of only 0.658%. The obtained constitutive relationship provides a reliable theoretical basis for generalized Reynolds number calculation and wellbore friction prediction, offering significant engineering guidance for CO₂ foam fracturing design.
Establishment of Pigging Model for CO2 Long-distance Pipeline Pigging Devices and Research on Pigging Performance
CO2 pipeline transportation is a key link in the development of carbon capture, utilization and storage (CCUS) technology. Due to the presence of impurities in the gas source and the special transportation conditions, hydrates are prone to form during the pipeline transportation of CO2. Therefore, pigging operations need to be carried out to ensure the safe and smooth operation of the pipeline. Based on the CO2 pipeline pigging parameters in the carbon capture and storage process of Kingsnorth, a pigging numerical model with the help of the pigging theory and pigging module of OLGA software was constructed in this study. The model verification results show that under the basic and full transportation volume conditions, the relative errors of the simulated values and the on-site detection values of the pigging time of the supercritical/dense-phase CO2 pipeline and the pigging speed at the pipeline outlet are 4.20%, 4.17%, 3.17%, and 3.86% respectively, all within the acceptable range of the project. Based on this model, a simulation study was conducted on the pigging work of a certain supercritical CO2 long-distance pipeline. The results show that the pigging effect of the intelligent pigging device is superior to that of the polyurethane mechanical pigging device. The pipeline pigging model established in this research can accurately predict the pigging performance of CO2 long-distance pipelines, providing a research method and guidance for the optimization of CO2 pigging devices.
Multidisciplinary Collaborative Treatment for Bilateral Posterior Tooth Loss Based on Occlusal Reconstruction: A Case Report
Objective To evaluate the value of occlusal reconstruction in multidisciplinary treatment for patients with long-standing bilateral posterior tooth loss, providing precise treatment references for complex dental arch defects with severe abrasion. Methods: A 66-year-old patient with long-standing bilateral maxillary posterior tooth loss, combined with severe full-mouth abrasion, deep overbite, and chronic apical periodontitis underwent imaging to assess alveolar bone conditions and temporomandibular joint status. The Gilbach splint precisely determined the vertical dimension of occlusion (elevated by 5 mm). Using impressions andCAD/CAM technology to fabricate a splint for occlusal elevation, establishing the correct vertical dimension. This restored the patient's lower third facial height, chewing function, and aesthetic appearance. Treatment was implemented in four phases: basic therapy, occlusal adjustment, final restoration, and long-term maintenance. Outcomes were evaluated during a 3-year postoperative follow-up. Results: Occlusal reconstruction restored normal lower third facial height with significantly improved masticatory function. Implant osseointegration remained stable throughout follow-up, with no ceramic fractures or prosthetic loosening. Temporomandibular joint function was normal, and patient satisfaction was high. Conclusion Occlusal reconstruction effectively restores masticatory function in patients with long-standing bilateral posterior tooth loss, improves occlusal relationships, and maintains long-term stability.
Multimodal Sensing and Intelligent Disinfection Technology in Indoor Integrated Research and Application of Air Quality Management
This study addresses the practical needs of multi-parameter sensing and dynamic regulation in current indoor air quality management. Targeting the insufficient integration among monitoring, disinfection, and control components in existing purification systems, we adopt a research approach combining multimodal information fusion and closed-loop feedback control. Through theoretical modeling, system integration, and experimental testing, we explore the synergistic integration of multimodal sensing and intelligent disinfection technologies. By constructing a sensing unit incorporating nucleic acid fluorescence detection, laser particle counting, and multi-parameter gas sensors, combined with dynamic control strategies based on real-time sensor data, the system drives adjustable ultraviolet, low-temperature plasma, and photocatalytic modules to achieve adaptive disinfection. The system interconnects with air conditioning equipment via IoT protocols and incorporates power optimization algorithms to balance purification efficacy and energy consumption. Comparative analysis with traditional solutions demonstrates the feasibility of this integrated approach in enhancing comprehensive indoor air quality management. The research indicates that this integrated pathway provides a viable technical solution for collaborative and precise indoor air quality regulation.
Study on Heat Transfer Characteristics of Brush-Type Sealing Labyrinth
This study addresses the significant deviation between actual heat consumption rates and design values caused by inter-stage air leakage in a power plant steam turbine's staggered-tooth labyrinth seal system. Focusing on retrofitting existing labyrinth seals, we implemented brush seals at specific stator sealing tooth positions based on field operational data. The proposed hybrid system demonstrates that maximum temperature serves as the primary thermal performance metric for evaluating structural and operational parameters. Key findings include: 1) Positive correlations exist between brush wire diameter, bundle thickness, brush ring inner diameter, temperature, and rotational speed with maximum temperature, while negative correlations are observed for brush arrangement angle, front/rear plate height, brush ring outer diameter, sealing clearance, and pressure differential. Labyrinth tooth clearance has minimal impact. 2) Temperature variations primarily result from frictional heat generation and leakage variations caused by parameter adjustments.
Coal Series Sedimentary Environment and Coal Accumulation Characteristics of Xinyuan Coal Mine in Qinshui Coalfield
The Xinyuan Coalfield is located in Shouyang County, northwest of the Qinshui Coalfield. The primary coal-bearing strata within the field consist of the Upper Carboniferous Taiyuan Formation and the Lower Permian Shanxi Formation. Distinct coal accumulation environments have resulted in significant differences between these two strata in lithological composition, facies characteristics, and coal-bearing properties. Both formations represent transitional environmental deposits. The Taiyuan Formation features barrier coast and deltaic sedimentary systems, with stable and substantial thickness at coal seams No.8, 9, and 15, constituting stable recoverable coal seams across the region. In contrast, the Shanxi Formation develops deltaic sedimentary systems based on pre-deltaic and deltaic foreland deposits at the top of the Taiyuan Formation. While coal seams No.3 and 6 exhibit relative stability, their thickness varies, making them locally recoverable coal seams. Through systematic analysis of the Xinyuan Coalfield's stratigraphy, age determination of coal-bearing strata, coal seam correlation, and sedimentary environment evolution, this study summarizes the coal accumulation characteristics within the field, providing geological evidence for regional coal resource exploration and development.
Structural Design and Dynamic Sealing Failure Optimization of Metal C-Rings
Targeting the miniaturized static sealing and control valve radial dynamic sealing conditions, this paper constructs an integrated “Design-Verification-Optimization” research framework for metal C-rings. Based on the Inconel X750/718/Ag multilayer composite structure, high-temperature and high-pressure static sealing tests and reciprocating dynamic sealing wear studies were conducted. The results indicate that the helium leak rate of this C-ring at room temperature reaches 6.6×10-9 Pa• m3/s, and it passed the verification of 21.5 MPa water pressure and 40 high-temperature cycles. Dynamic sealing failure is dominated by friction and wear; when the sleeve bore roughness is reduced to Ra=0.8 μm, the life is significantly extended to over 15,000 cycles, with limited benefits from further reducing roughness. Considering both cost and performance, it is recommended to set the roughness threshold for both the dynamic sealing mating surface and the static sealing surface at Ra≈0.8 μm.
Experimental Study on The Mechanical Properties of High Territory-Steel Fiber-Rubber Concrete Under Multi-Component Coupling Effects
In this paper, the effects of multi-component coupled dosages on the compressive strength, splitting tensile strength, and flexural strength of concrete, a three-factor, three-level orthogonal experiment was employed, and the analysis of variance method was used to determine the primary and secondary order of the effects of materials on concrete properties. Results indicate that the single incorporation of rubber particles into traditional concrete optimizes impact resistance via elastic deformation but results in a significant reduction in strength. In contrast, high territory improves strength and durability by generating C-S-H gels through its pozzolanic activity, while steel fibers establish a three-dimensional supporting network that enhances crack resistance and toughness. The combined incorporation of high territory compensates for the strength loss by virtue of its filling effect and pozzolanic reaction, while steel fibers inhibit the propagation of micro-cracks at the rubber interface. SEM analysis results reveal that the hydration products of high territory–steel fiber-rubber concrete exhibit a smoother surface, fewer weak interfacial zones and better bonding between aggregates and cement mortar, which significantly improves the overall performance of the concrete.
Research on the Correlation between Microstructure and Macroscopic Properties of Magnesium Oxysulfide Foamed Lightweight Blocks Based on Proportion Optimization
To address the high carbon emissions and resource consumption of traditional Portland cement, this study prepared lightweight and high-strength magnesium oxysulfide foamed blocks based on magnesium oxysulfide cement by optimizing the raw material ratio, adding composite modifiers and compounding mineral admixtures. The effects of oxygen-sulfur ratio, water-sulfur ratio, citric acid-potassium aluminum sulfate composite modifier, silica-fly ash double admixture system and glass fiber reinforcement on the mechanical properties, water resistance and volume stability of the material were systematically investigated. The intrinsic correlation between macroscopic properties and microscopic structures (hydration product morphology, pore distribution, fiber-matrix interface) was revealed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the optimal raw material ratio was MgO: MgSO₄:H₂O = 8:1:20, and the compound modifier (citric acid 1.2wt% + potassium aluminium sulfate 2.0wt%) significantly increased the softening coefficient from 0.41 to 0.91; The double addition of silica fume and fly ash (total dosage 30%, mass ratio 1:2) simultaneously increased compressive strength (66.2 MPa) and flexural strength (13.35 MPa), and significantly improved volume stability (28-day drying shrinkage strain reduced to 2304 µm/m). The lightweight block (with a bulk density of 800 kg/m³) prepared by physical foaming process has a compressive strength of 12.2 MPa and a 28-day volume shrinkage rate of only 1.11%; An addition of 0.6wt% of glass fibre can further enhance early strength and crack resistance. Microscopic analysis indicates that the increased generation of 5·1·7 phase (5 mg (OH)₂·MgSO₄·7H₂O) after modification, optimized crystal morphology, and densification of structure are the keys to the macroscopic performance improvement. The wall mechanics test confirmed that the compressive, shear and flexural strengths of the masonry met the requirements of the code. This study provides theoretical and experimental evidence for the industrial production and application of magnesium oxysulfide foamed lightweight blocks.
Flow Characteristics and Cavitation Behavior of an Industrial Gate Valve Based on CFD and Fluid–Structure Interaction Analysis
To reduce the dependence of small- and medium-sized enterprises on physical experiments during valve research and development, this study employs the SolidWorks Flow Simulation module to visualize and analyze the internal flow field of a DN100 industrial gate valve under different opening conditions. A steady-state computational fluid dynamics (CFD) model is established to systematically investigate the flow characteristics, pressure drop, flow resistance coefficient, and cavitation-sensitive regions at various valve openings. The influence of valve opening reduction on internal flow behavior and cavitation evolution is revealed. The results indicate that, with decreasing valve opening, the internal flow field exhibits pronounced pressure drops, significant velocity variations, and an expansion of cavitation-sensitive regions. At small openings, a distinct negative-pressure zone forms on the leeward side of the gate plate, accompanied by strong vortical structures and high-velocity jet flows. Meanwhile, the cavitation region expands progressively as the opening decreases, indicating an increased cavitation risk. The present study provides a valuable theoretical reference for analyzing valve flow characteristics under complex operating conditions.
Research on the Sustainable Development of the Dujiangyan Irrigation System from a World Heritage Perspective
It has been 2280 years since the construction of water conservancy projects in Dujiang Dam, and the water conservancy projects in Dujiang Dam have been running continuously for more than 2000 years. It is not only a miracle in Chinese history, but also a unique pearl in the history of water conservancy projects in the world. The purpose of this paper is to study the Dujiang Dam of water conservancy projects in the world cultural heritage, and to deeply excavate the various values of the cultural heritage of modern Dujiang Dam. Summarize the relevant valuable cultural connotations and immortal spirit, and refer to excellent cases. In view of the current situation of Dujiang Dam protection, management and development, the remaining problems were solved. Today, with the rapid development of science and technology, new technologies have also brought Dujiang Dam new opportunities for the modernization of water conservancy projects. Both protection management and development should actively seek both offline and online. We should make every effort to carry forward the connotation and spirit of the deep culture of Dujiang Dam, base ourselves on the present and look forward to the future. It not only finds a new way for the development of water conservancy projects in Dujiang Dam, but also provides reference value for the sustainable development of other cultural heritages of water conservancy projects.
Non-Destructive Detection of Composite Defects Using Millimeter Continuous Wave by Analyzing Critical Change of Amplitude for S11
Artificially engineered defects were intentionally embedded into planar composite specimens, which were subsequently characterized using a vector network analyzer in conjunction with a custom-built two-dimensional scanning platform. The spatial locations of these pre-implanted defects were determined by analyzing consistence in the reflected S₁₁ scattering parameters, demonstrating that sub-terahertz wave responses are sensitive to structural irregularities within layered media. Furthermore, the critical interfaces were determined by coordinated analysis of amplitude local maxima and the deviation local maxima. The proposed methodology was validated through comparative assessments across multiple aeronautical-grade composite materials, confirming the efficacy of both the experimental hardware configuration and the developed imaging algorithm. This work contributes to the advancement of sub-terahertz inspection techniques and associated non-destructive testing (NDT) methodologies, offering potential improvements in aviation safety through enhanced defect detection capabilities.
Research Status and Challenges of Domestic Sewage Treatment Technology in Mining Areas
Due to the impact of mining activities, domestic sewage in mining areas contains heavy metals, high salt content, and refractory organic matter, making its treatment significantly more difficult than urban sewage. This article systematically reviews the research progress in this field in recent years, indicating that the bio-physicochemical combined process has become a mainstream technology. The treatment efficiency can be improved through microbial agent enhancement, membrane material modification, and ecological restoration. However, heavy metal inhibition and low-temperature inactivation remain core challenges. In the future, focus should be placed on resource recovery and intelligent operation and maintenance to promote sustainable treatment of mining area sewage.
Research on the Impact of Optimizer Design on Generalization Performance in Ship Trajectory Prediction Based on LSTM
Ship trajectory prediction using the Automatic Identification System (AIS) is a core task in intelligent shipping. Focusing on straight-line navigation segments, this paper constructs a unified multi-target LSTM prediction framework that simultaneously forecasts four key variables: longitude, latitude, speed, and course. Through five-fold cross-validation and under identical network architectures, we compare the performance of three models: standard LSTM, attention-enhanced LSTM, and LSTM optimized with Lookahead-RAdam. Experimental results demonstrate that the LSTM model incorporating the Lookahead-RAdam optimization strategy significantly outperforms the other approaches across all evaluation metrics. Further analysis reveals that optimizer design has a far greater impact on model generalization than network architecture complexity. This study proposes an efficient paradigm for maritime spatiotemporal sequence modeling: “simple architecture + advanced optimization.”
Coupling Effects of Heterogeneous Traffic Flow and Facility Design on Capacity of Tunnel Group Sections in CAV Environment
With the advancement of connected and autonomous vehicle (CAV) technology, the traffic flow in highway tunnel group sections has transformed into a heterogeneous mix of CAVs and human-driven vehicles (HDVs). The operational capacity of these sections is influenced by multiple interdependent factors, including traffic composition, speed limit control, and tunnel configuration. Understanding the coupling mechanisms among these factors is essential for enhancing both efficiency and safety. In this study, we first analyze the characteristics of heterogeneous traffic flow under CAV conditions and the structural features of various tunnel group layouts. An integrated simulation model is then developed by combining an enhanced NaSch cellular automaton model with the Intelligent Driver Model (IDM), capturing the dynamic interactions among heterogeneous traffic, speed limits, and tunnel geometry. Through multi-scenario simulations, the individual and coupled influences of these factors on tunnel group capacity are systematically examined. The results indicate that: (1) Increasing the CAV penetration rate improves operational capacity significantly, with capacity growth tapering off after the rate exceeds 60%; (2) Each tunnel configuration corresponds to an optimal speed limit range, and a mismatch can cause considerable capacity reduction; (3) The coupling effect of traffic composition and speed control is particularly pronounced in long-span tunnel groups, where appropriately matching CAV penetration with speed limits can maximize capacity. This study elucidates the internal coupling mechanisms governing the operational capacity of tunnel groups and offers theoretical and technical support for the refined design and intelligent management of highway tunnel sections in a CAV environment.
An Improved A* Based Path Planning and Control Strategy for Autonomous Sanitation Vehicles in Campus Environments
To address the problems of "missed operation tasks, high risk of path scraping, and low search efficiency" in the path planning of autonomous sanitation vehicles in smart parks, this paper proposes an optimization scheme based on an improved A* algorithm and Bézier curve. Based on the traditional A* algorithm, the neighborhood expansion is optimized to reduce invalid traversal, and redundant nodes are pruned through the "collinearity judgment + safe distance verification" strategy. A cubic Bézier curve is introduced to smooth the polyline path, adapting to the kinematic constraints of sanitation vehicles. Experimental results show that the number of traversed nodes of the improved A* algorithm is reduced, with significantly improved path safety and real-time performance guaranteed. The Bézier curve achieves continuous curvature, solving the problem of sudden steering. The proposed path planning scheme balances the requirements of operation completeness, kinematic safety, and planning efficiency, providing technical support for the intellectualization of environmental maintenance in smart parks.
Performance Comparative Analysis and Structural Optimization of Split Mechanical Seals for Pumps
This paper focuses on the sealing performance of split mechanical seals used in pumps, proposing a new split seal structure with the sealing ring and support component installed at a 90° offset, and conducting a comparative performance study against traditional coplanar arrangements. The research establishes a 3D numerical model, combining ANSYS numerical simulation with orthogonal experimental methods to systematically analyze the impact of the gap between the end face and split face on leakage. The results show that the new design exhibits superior sealing performance under various gap conditions. Furthermore, through range and variance analysis, the significant order of the impact of each structural parameter on leakage was determined, optimizing a combination of structural parameters that achieved the best sealing performance, significantly reducing leakage, and providing a theoretical basis and reference for the structural design and performance improvement of split mechanical seals.
Study on the Osteogenic Effects of Yuliang Collagen Implantation Without Bone Grafting at 6–9 mm from the Maxillary Sinus Floor: A Prospective Cohort Study
Objective: To evaluate the osteogenic effect and implant survival rate in the peri-implant region following simultaneous maxillary sinus floor elevation via the crestal approach and Yuliang collagen (a high-purity type I collagen matrix) implantation, without additional bone grafting, in patients with residual alveolar bone height (RBH) of 6–9 mm in the maxillary posterior region. Methods: A prospective cohort study design was employed, enrolling 42 patients (50 implants) requiring maxillary posterior implant restoration with RBH of 6–9 mm. All patients underwent bone-free transalveolar sinus floor elevation, with Yuli'an collagen implanted in the elevated space during surgery. Immediate postoperative and 6-month/12-month postoperative cone-beam computed tomography (CBCT) scans were performed to measure new bone height (NBH) above the implant apex and bone density changes (gray-scale analysis). Surgical complications and implant survival were recorded. Results: We followed up on 50 implants in 42 patients for an average of 14.3 months. One case involved minor periosteal perforation during the maxillary sinus lift, which did not affect final healing. No implant infections or failures occurred. The implant survival rate was 98% (49/50). At 12 months postoperatively, CBCT measurements revealed new bone formation above the implant apexes. Compared to the preoperative RBH (7.2 ± 0.8) mm, the mean height of newly formed bone was (3.8 ± 0.9) mm, with an average increase of approximately 3.4 mm in sinus floor bone height. For assessing the density of newly formed bone, we used the density of the contralateral normal maxillary bone as a reference. The mean bone density in the newly formed bone area reached (65.2 ± 7.1)% and (88.7 ± 5.3)% of the contralateral normal maxillary bone density at 6 and 12 months postoperatively, respectively, indicating good maturity of the newly formed bone. Conclusion: For maxillary posterior regions with a ridge height (RBH) of 6–9 mm, sinus floor elevation via the crestal approach using Yuliang collagen protein alone (without bone grafting) can guide the formation of sufficient quantities of high-quality new bone. This approach achieves clinical osteogenic outcomes and high implant survival rates comparable to traditional bone grafting methods. YuLiAn collagen, serving as a space-maintaining and guiding matrix, demonstrated excellent biocompatibility and osteogenic potential in this procedure, offering a reliable option for simplifying surgical steps, reducing patient costs, and minimizing trauma.
Pollution monitoring and assessment of heavy metals in leafy vegetable: A case study of a typical industrial district
Long-term consumption of contaminated leafy vegetables poses potential health risks, particularly in areas affected by heavy metal (HM) pollution. To assess the status of vegetable contamination in China and provide a foundation for the experimental sampling of this study, HM data for vegetables published between 2017 and 2021 in the China National Knowledge Infrastructure and Web of Science databases were reviewed. Based on the accumulation characteristics of HMs in vegetables reported in the literature, this study analyzed the total amount of HMs in leafy vegetables from Qingshan District, a typical industrial area. The results showed that the average concentrations of HMs in the four vegetables did not exceed the limits set by national food safety standards. However, at certain sampling points, the HM levels in amaranth were close to or even exceeded the permissible limits, indicating a potential risk of Cd contamination in amaranth. The single-factor pollution indicated that the four HMs across the four vegetables were all classified as "uncontaminated." Notably, amaranth and water spinach exhibited relatively higher single-factor pollution indices for Cd, while vegetable shoots and Chinese cabbage showed higher single-factor pollution indices for Hg.
Optimization Analysis of Exposure Machine Light Source Layout and Heat Dissipation Structure Based on CFD Technology
This paper presents a CFD-based optimization analysis of the light source layout and heat dissipation structure of PCB exposure machines. As the PCB manufacturing process becomes more advanced, exposure machines face issues such as uneven light sources and inadequate heat dissipation, affecting exposure quality and equipment stability. The study investigates the impact of light source layout on exposure uniformity and analyzes the cooling effect of the air-cooling system under different operating conditions. The results show that optimizing the light source layout significantly improves exposure uniformity, reduces light source overlap and dead zones, enhancing overall exposure performance. While the air-cooling system effectively reduces internal temperatures, high-load conditions lead to uneven temperature distribution, especially near the light source plate, affecting long-term operational stability. The paper proposes improvements to the airflow path and strength of the air-cooling system to further enhance temperature uniformity and equipment stability. This research provides valuable insights for the design and optimization of exposure machines in PCB manufacturing.
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Research on the Application of Refractory Materials in The Steel Industry
As the core basic material of the high-temperature production process of the iron and steel industry, the performance adaptability of refractories directly determines the smelting efficiency, product quality and production cost. In view of the outstanding problems faced by refractories in the current green and low-carbon transformation of the iron and steel industry, such as erosion and wear, uneven life span, and environmental protection hazards, this paper summarizes the application scenarios and problems of refractories in the iron and steel industry on the basis of literature research, and then puts forward optimization strategies such as formula improvement, process optimization and environmental protection upgrade, which provides technical support for the efficient adaptation and application of refractories in the iron and steel industry, and is of great significance to promoting the green and high-quality development of the industry.
DAP-YOLO: A Multi-scale Adaptive Fusion Human Detection Model for Aerial Photography Disaster Scenarios
In emergency rescue operations for natural disasters and traffic accidents, rapidly and accurately detecting core disaster areas and identifying survivors in urgent need of rescue holds significant practical importance. To address this, this study proposes a multi-scale adaptive fusion human detection model for aerial disaster scenes—DAP-YOLO. First, the PPA module is introduced, employing multi-branch parallel fusion to enhance focus on small objects. Second, the C3k2_DWR module utilizes DWR to expand the receptive field, mitigating feature information loss during downsampling. The ASFF module is integrated into the detection layer, dynamically assigning weights to adaptively adjust the contribution of feature maps at different scales. Additionally, a micro-detection structure is designed for small objects, significantly reducing model parameters while enhancing detection performance. Experiments demonstrate that DAP-YOLO outperforms YOLO11n on the C2A dataset by 6.70% in recall, 5.30% in mAP50, 5.10% in mAP50-95, and 4.63% in F1-Score. and on the SARD dataset, improvements of 6.40%, 4.10%, 8.20%, and 4.78% respectively. Further comparison of mAP50-95 reveals that DAP-YOLO outperforms YOLOv12n by 5.10% while significantly surpassing the lightweight YOLOv13n model. These experiments validate the effectiveness of human detection models in disaster scenarios, providing technical support for drone-based post-disaster search and rescue operations.
Green Synthesis of Carbon Quantum Dots and Performance Optimization for Bioimaging
The rapid development of nanotechnology has brought about many new types of material for biomedical use, and among them, fluorescent nanomers are the most outstanding, used as bio imaging materials. The conventional semiconductor quantum dots, as good as they look when it comes to the light show they produce, carry a weighty burden: because of the heavy metal inside them, they can cause real problems for living things and nature too. As a new type of quantum dots, carbon quantum dots (CQDs) exhibit good biocompatibility, low toxicity, high photostability and adjustable photoluminescence. Another big change is the creation of green synthesis methods. They use nature-based things that can grow again and are cheap. These things aren't harmful to other living things. They fit in with how sustainable chemistry works. This paper gives an overall summary on the green synthesis of CQDs with different precursors, such as fruit peels, plant leaves, food waste, hydrothermal method, microwave-assisted method, and pyrolysis and so on. Also examines key ways of improving its performance so as to make it suitable for use with high contrast bioimages. They can be heteroatom doped with nitrogen, sulfur, phosphorus, etc., to increase quantum yield through changing electronic band structure, passivation and functionalization to control emission wavelengths and give targeting function towards certain organelle or diseased cells, control synthesis process to become more robust in harsh bioconditions. Review talks about how these improved, greener CQDs get used properly in both test tubes and living creatures, showing their cool potential to be the newest kind of safe and good light-markers for checking sick people and making medical studies better. the shift toward making CQDs that are both sustainable and can be scaled up for producing really good nanotech materials moves us closer to bringing these things into use clinically, so doctors can make better images of patients that are safer and easier to understand.