In the intersection scenario, the running state of social vehicles, the control state of traffic lights and the accurate identification of track components have become the technical bottlenecks restricting the promotion and application of track inspection robots. Aiming at the requirements of track health inspection, firstly, the vision inspection system of the track inspection robot and the technical scheme of the navigation system was presented based on “Beidou +5G”. Secondly, the vision detection system model was built based on YOLOv8 algorithm, and the web crawler technology was innovatively used to capture sample data about traffic lights and car taillights from open source video resources to train the vision detection model. Then, transfer learning method and early stop method were used to optimize the detection accuracy of the trained model. The research results show that after adopting YOLOv8 algorithm and optimizing the model with transfer learning method and early stop method, the inspection robot can effectively detect the track components, vehicles and traffic lights at the switch junction, and effectively improve the inspection efficiency and accuracy.

Buried pipeline is an important part of oil and gas transportation. The subsidence of gob area will cause the corresponding subsidence of the pipeline passing through the gob area, resulting in pipeline deformation, fracture and other accidents. Taking Puxian-Hejin pipeline crossing coal mining subsidence area as the research background, 3D printing technology was used to make up for the mismatch in mechanical similarity between pipeline simulation materials and geotechnical simulation materials, and the coupling simulation experiment between pipeline and rock and soil was constructed. The mining response of buried pipeline caused by coal mining was analyzed, and the correlation between pipeline movement deformation and stratum movement deformation was established. The research shows that the buried pipeline and the underlying rock strata do not synchronously settlement, resulting in delamination between the overlying rock strata and the underlying rock strata. The pipeline bends and deforms under the overlying rock load and its own weight. When the delamination span is large enough, the bending tensile stress on the bottom of the pipeline exceeds the allowable stress, resulting in tensile failure. The subsidence value of the buried pipeline is about 1.21 times of the formation subsidence value, and only 18% of the horizontal deformation of the formation is transmitted to the pipeline. The research results have guiding significance for the safe laying and daily maintenance of pipelines in subsidence area.

Aiming at the problems of nonlinearity, large delay, uncertain model parameters and weak anti-interference ability in the temperature control system of variable air volume air conditioning supply air, a closed-loop control system of supply air temperature based on active disturbance rejection control (ADRC) was designed. In order to overcome the difficulty in parameter adjustment of active disturbance rejection controller, an improved grey wolf optimization (IGWO) algorithm was proposed to optimize controller parameters. By introducing chaotic mapping, nonlinear convergence factors, dynamic weights and dimensional learning strategies into grey wolf optimization (GWO), the population diversity was increased and the balance between search and exploitation was taken into account. The advantages and feasibility of the proposed algorithm were verified by MATLAB simulation. The experiment further proves that compared with the traditional proportional integral derivative (PID) controller and the traditional gray wolf algorithm, the IGWO algorithm can shorten the supply air temperature overshoot by 45.3% and 8.9%. The adjustment time is reduced by 34.8% and 11.2%, the steady-state error is smaller, and the system is more energy efficient.

Aiming to address the issue of accurately measuring the slurry pH value during the operation of limestone-gypsum wet flue gas desulfurization (WFGD) system, which hinders the efficient operation of WFGD, a prediction model for FGD system pH based on bi-directional gated recirculation unit(BiGRU) has been developed. Firstly, the raw data were cleaned and normalized. Secondly, based on the maximum information coefficient analysis, 13 characteristic values were obtained as input variables and pH as output variables, and a slurry pH model was established. Finally, the model was run and the results were evaluated. Compared to LSTM and GRU, the results indicate that the mean absolute error of this mathematical model decreases by 11.95% and 24.92%, while the root mean square error decreases by 10.64% and 19.49%. Additionally, the coefficient of determination improves by 1.79% and 3.08% respectively. This demonstrates that the BiGRU-based pH predictive model exhibits high accuracy and stability, making it valuable for engineering applications and providing an important reference for predicting pH models in existing desulfurization tower systems.

The complex nonlinear characteristics and dynamic friction properties of the integrated brake-by-wire system were recognized as challenges for precise hydraulic pressure control. To address these issues, a precise hydraulic force control strategy was proposed for the integrated brake-by-wire system. Firstly, the structure and control framework of the integrated brake-by-wire system were analyzed, and equivalent simplified models were established for each component to facilitate controller design. Secondly, a three-layer cascade pressure control method was introduced for active braking in the integrated brake-by-wire system. Specifically, the pressure control layer was designed based on the active disturbance rejection control method, which mitigates the effects of hysteresis nonlinearity in the hydraulic system. The position control layer employs a robust sliding mode variable structure control method and addresses the dynamic and static friction issues in the transmission mechanism. The current control layer was designed using the linear matrix inequality method to enhance the braking motor's dynamic following performance. Joint simulation tests using AMESim-Simulink demonstrate that the integrated brake-by-wire system achieves good pressure control performance across various operating conditions, maintaining the steady-state pressure tracking error within 0.1 MPa, compared to the traditional proportion-integration(PI) control method, the mean transient pressure tracking error is reduced by 0.14 MPa using the proposed method, the mean steady-state pressure tracking error decreases by 0.8 MPa, and the response lag time is lowered by 0.04 s, which verifies the effectiveness of the control strategy proposed.

In order to explore the relationship between the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) and the risk of rapid decline in kidney function, data from the China health and retirement longitudinal study (CHARLS) conducted in 2011 and 2015 was utilized. It includes 4 055 participants aged 40 and above with a baseline estimated glomerular filtration rate (eGFR) of at least 60 mL/(min·1.73m²), calculated using serum creatinine and cystatin C levels. Rapid kidney function decline is defined as a decrease in eGFR of 3 mL/(min·1.73m²·a). A multivariable logistic regression model was used to investigate the association between NHHR and the risk of rapid kidney function decline. Additionally, restricted cubic spline and threshold effect analyses were used to evaluate the dose-response relationship. The results show that over the 4-year follow-up, 447 participants (11.02%) experienced rapid decline in kidney function. In the fully adjusted multivariable logistic regression model, those in the highest NHHR group (T3) faced a 1.94-fold increased risk of rapid kidney function decline compared to the lowest NHHR group (T1) (OR=1.94,95%CI:1.46~2.61). As a continuous variable, each unit increase in NHHR is associated with a 1.21-fold increase in risk (OR=1.21, 95%CI:1.08~1.36). The restricted cubic spline analysis demonstrates a near logarithmic curve saturation effect between NHHR and rapid kidney function decline (P_nonlinearity<0.05). It is concluded that with NHHR ≤3.52, the risk increases as NHHR rises, while NHHR >3.52 marks a saturation point. In conclusion, among middle-aged and elderly individuals, a higher NHHR is linked to a greater risk of rapid decline in kidney function, displaying a nonlinear relationship.

To solve the problem that the wire rope swing angle is too large during the load lifting and lowering process of the bridge crane, a fuzzy layered sliding mode control method was proposed with the single pendulum model of the bridge crane as the research object. The method firstly establishes the bridge crane single pendulum model system, designs the two-layer sliding mode surface joint control based on traditional sliding mode control, combines the layered sliding mode surface with fuzzy control to create the controller, proves the Lyapunov stability of the closed-loop system of the bridge crane under the method through theory and carries out simulation experiments. The simulation results show that compared with the LQR controller and the multi-sliding mode controller, the trolley arrives at the desired position in 68% less time, and the maximum swing angle of the load is reduced by 15%, which achieves a good anti-swing effect.

In order to analyze the distortion effect of thin-walled box girder under lane load, the distribution law of stress amplification coefficient in thin-walled box girder was studied. The distortion angle and distortion generalized bending displacement were taken as node displacements. Based on the initial parameter solution of the homogeneous equation of the distortion control differential equation, the thin-walled box girder was divided into beam segment elements, and its element stiffness matrix and equivalent node load array were derived. Using Fortran language and referring to the calculation program FRAME2 for planar frame structures, a finite element program for beam segments that can be used to analyze the distortion effect of thin-walled box girders was obtained. The program was used to analyze the variation laws of the distortion internal forces and stress amplification factors of box girders under lane loads. The results show that the distortion warpage stress of three-span continuous box girder with variable cross-section under the action of lane load has a sudden change at the place of concentrated load, where the maximum and minimum values are obtained, the longitudinal distribution of stress amplification factor is similar to the longitudinal distribution of distortion warpage normal stress, both of which are symmetrically distributed along the span, the magnification factor of normal stress at the top and bottom of the section is 1.080 and 1.180 respectively. The points with smaller bending stress should not be considered when the magnification factor is taken into account.

The high-altitude & dense-vegetation landslide is difficult to investigate and lack of data, its appearance and subsurface information also difficult to get. Therefore it is difficult to identify and threat the road greatly. A case study of the Xiaojiapo landslide was presented. Detailed on-site geological surveys were performed, and drone-based oblique and orthophoto imaging techniques were employed to get the landslide's characteristics. Historical deformation of the landslide was analyzed using satellite image, airborne LiDAR was used to collect point cloud and digital imagery data of the landslide surface. A digital elevation model and centimeter-level three-dimensional model of the landslide surface were created following vegetation removal to assess the surface characteristics. The combined investigations reveal that the Xiaojiapo landslide is situated at an elevation of 3 030 m with a vegetation coverage reaching up to 90%. It is a typical landslide with high-altitude and dense vegetation. The key internal factors contributing to the landslide including the unique alpine valley topography, the slope structure with advantageous free faces, and easily erodible geological layers. Precipitation induces internal water infiltration, which reduces the strength of the rock and soil mass. Additionally, freeze-thaw cycles further diminish slope strength, while earthquakes and road constructions disturb the internal structure, weakening it further. These combined internal and external factors drive the landslide deformation. This study offers technical insights for the landslide identifying, early-warning, and mitigation of road landslides in high-altitude regions with dense vegetation.

Long-term stockpiling of coal fly ash releases a large amount of toxic and hazardous substances, posing a threat to the soil and water environment. In order to have a comprehensive understanding of the research progress in this field, a bibliometric method was conducted to systematically and deeply visualize and analyze the relevant literature in CNKI and Web of Science databases from the period of database construction to 2023. The results show that the annual total number of publications in this field is generally on the rise. Among them, Chinese scientists have conducted a substantial amount of research in this field, accounting for the highest publication volume, which makes up 18.87% of the total, providing important scientific foundation for subsequent studies. The betweenness centrality of publications from the United States (0.51) is significantly higher than that of other countries, and its research results have greater international influence. The research hotspots focus on contaminants like heavy metals in coal fly ash, investigating their leaching and release patterns under various conditions, and revealing the environmental impacts of contaminants migration from coal fly ash landfills. Based on high-frequency keyword analysis, the composition of contaminants in coal fly ash and the types of contaminants potentially released into the water environment were examined. A systematic review and analysis of contaminants release mechanisms, release regularity, key influencing factors, and the migration regularity of mechanisms in environmental media were conducted. Future research should further focus on the release of heavy metals such as Pb, Cr, and Hg, trace elements like As, Se, and Mo, and specific mechanisms such as F^-, Cl^-, and $\mathrm{SO^{2-}_{4}}$, $\mathrm{PO^{3-}_{4}}$ during the coal fly ash stockpiling. Studies should explore the release characteristics of these mechanisms under complex environmental conditions, investigate whether synergistic or inhibitory mechanisms exist between various factors, and establish quantitative relationships between mechanisms indicators in the solid phase of coal fly ash and their release into water environment. This will provide a theoretical basis for scientifically evaluating the environmental impacts of coal fly ash and effectively preventing potential threats to water environment.