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In order to ensure the straightening quality of spindle rod, reduce the labor intensity of workers and improve the working environment of workers, the causes of straightness error and deformation of spindle rod after hot rolling forming, longitudinal cutting forming, heat treatment and manual straightening were analyzed. The method of straightening the spindle rod with the automatic loading and unloading device of the manipulator on the thread rolling machine was adopted. With the method, the spindle rod was placed on the support plate between the two straightening rollers, and the moving roller moved forward, straightened, retreated and returned to the original position along the radial direction, with the spindle rod repeatedly bent and deformed along the axial direction through the spiral groove of the roller to achieve the purpose of straightening. At the same time, the structural characteristics and dimensions of the straightening roller and the support plate were introduced. The experimental results show that the spindle rod is straightened on the thread rolling machine after rough grinding, and the qualified rate is more than 90%; and the rod output reaches 3 000, which creates conditions for intelligent manufacturing of spindle rod.

The urgent demand for stable and highly efficient bifunctional electrocatalysts for the oxygen reduction/evolution reactions (ORR/OER) is pivotal in advancing energy conversion and storage technologies. Herein, we introduce a metal–organic framework (MOF)-derived bifunctional electrocatalyst Fe3Co-NC@900, featuring synergistically coupled dual single-atom sites (Fe/Co–Nx) and core–shell Co3Fe7@C nanoparticles. Leveraging the synergistic interactions of Fe–Nx sites with associated Co–Nx sites and core–shell nanoparticles within the MOF-derived nitrogen-doped mesoporous sheets and nanotubes, Fe3Co-NC@900 demonstrates outstanding ORR and OER performance, outpacing the Fe-NC@900 catalyst fabricated without Co incorporation. Specifically, it demonstrates superior ORR performance with a higher half-wave potential (E1/2) of 0.88 V and a small Tafel slope of 62.1 mV dec−1, surpassing the Pt/C benchmark (E1/2 of 0.82 V) and Fe-NC@900 (E1/2 of 0.788 V). Additionally, it demonstrates noteworthy OER performance, requiring a 1.572 V overpotential at 10 mA cm−2 current density, resulting in a significant bifunctional activity with a potential gap (ΔE) of 0.692 V, surpassing the Pt/C + Ir/C combination (ΔE = 0.748 V). Moreover, serving as a bifunctional air electrode, Fe3Co-NC@900 exhibits excellent performance in lab-made Zn–air batteries, with outstanding open circuit voltage, specific capacity, and cycling stability (>650 cycles), outpacing the Pt/C + Ir/C-based battery. [ABSTRACT FROM AUTHOR]

To better analyze the fluctuation characteristics and development law of tunnel deformation data, multifractal theory is applied to tunnel deformation analysis. That is, the multifractal detrended fluctuation analysis (MF-DFA) model is first utilized to carry out the multifractal characterization of tunnel deformation data. Further, Mann–Kendall (M–K) analysis is utilized to construct the dual criterion (∆α indicator criterion and ∆f(α) indicator criterion) for the tunnel deformation early warning study. In addition, the particle swarm optimization long-short-term memory (PSO-LSTM) prediction model is used for predicting tunnel settlement. The results show that, in reference to the tunnel warning level criteria and based on the Z-value results of the indicator criterion, the warning level of all four sections is class II. At the same time, through the analysis of tunnel settlement predictions, the PSO-LSTM model has a better prediction effect and stability for tunnel settlement. The predicted results show a slow increase in tunnel settlement over the next 5 days. Finally, the tunnel warning level and the predicted results of tunnel settlement are analyzed in a comprehensive manner. The deformation will increase slowly in the future. Therefore, monitoring and measurement should be strengthened, and disaster preparedness plans should be prepared. [ABSTRACT FROM AUTHOR]

In order to improve the stability, and sensitivity and response speed of moisture-sensitive sensors, the microarc oxidation process is used to realize the preparation of porous Al2O3 structure humidity-sensitive thin films on aluminum substrate and combined with magnetron sputtering process to realize the preparation of the humidity-sensitive sensor. After the Al2O3 moisture-sensitive films are prepared by the mechanical polishing, the microarc oxidation process platform and aging processes, moisture-sensitive films will be characterized by XRD and SEM. The results show that the peak intensity of α-Al2O3 diffraction peaks in Al2O3 humidity-sensitive thin films can be enhanced by increasing the microarc oxidation current. By building the humidity device platform for humidity-sensitive testing, the change of ambient humidity will lead to different changes of resistance and capacitance of the films, and the moisture-sensitive devices have better sensitivity at a lower frequency of 100 Hz. [ABSTRACT FROM AUTHOR]

The demand for tunnel construction continues to grow by leaps and bounds. Therefore, tunnel mechanization construction is receiving more and more attention for improving excavation ergonomics. To enhance the scientific and comprehensive evaluation results of tunnel drilling and blasting method excavation ergonomics, a set of evaluation methods of tunnel drilling and blasting method excavation ergonomics based on the game theory G2-EW-TOPSIS model is proposed. From the three dimensions of drilling efficiency, construction process duration, and synergistic influence factors, a tunnel drilling and blasting construction ergonomics evaluation index system consisting of 11 indicators such as perimeter hole drilling efficiency, drilling duration, construction quality, and comprehensive cost is constructed. The subjective and objective weights of evaluation indicators are calculated by using the improved sequential relationship analysis method (G2 method) and entropy weight method, respectively, and the combination weights are carried out by using game theory method (GTM) with the Nash equilibrium as the goal. The indices are classified into five grades: excellent (I), good (II), average (III), rather poor (IV), and poor (V), according to the daily tunnel construction. The excavation ergonomics index to be evaluated is calculated using the combined weights, and the comprehensive evaluation index of excavation ergonomics to be evaluated is calculated using the technique for order preference by similarity to an ideal solution (TOPSIS). The proposed rating model was used to analyze the excavation ergonomics of the Shangtianling Tunnel in the Chizhou–Huangshan High-Speed Railway using jumbo drills (JD) and drilling machines (DM) in large- and small-mileage construction, respectively, and to obtain the excavation ergonomics rating and comprehensive evaluation rating of each evaluation object. The research results show that the established excavation ergonomics evaluation model can effectively identify the main factors affecting the excavation ergonomics of the drill and blast method, and has a certain reference value. [ABSTRACT FROM AUTHOR]