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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 occurrence of landslide hazards significantly induces changes in slope surface displacement. This study conducts an in-depth analysis of the multifractal characteristics and displacement prediction of highway slope surface displacement sequences. Utilizing automated monitoring devices, data are collected to analyze the deformation patterns of the slope surface layer. Specifically, the multifractal detrended fluctuation analysis (MF-DFA) method is employed to examine the multifractal features of the monitoring data for slope surface displacement. Additionally, the Mann–Kendall (M-K) method is combined to construct the α indicator and f (α) indicator criteria, which provide early warnings for slope stability. Furthermore, the long short-term memory (LSTM) model is optimized using the particle swarm optimization (PSO) algorithm to enhance the prediction of slope surface displacement. The results indicate that the slope displacement monitoring data exhibit a distinct fractal sequence characterized by h (q) , with values decreasing as the fluctuation function q decreases. Through this study, the slope landslide warning classification has been determined to be Level III. Moreover, the PSO-LSTM model demonstrates superior prediction accuracy and stability in slope displacement forecasting, achieving a root mean square error (RMSE) of 0.72 and a coefficient of determination (R2) of 91%. Finally, a joint response synthesis of the slope landslide warning levels and slope displacement predictions resulted in conclusions. Subsequent surface displacements of the slope are likely to stabilize, indicating the need for routine monitoring and inspection of the site. [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]

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]

In this article, the strategy of co-doping Mn2+ ions with W6+ ions is used to improve the comprehensive dielectric performances of TiO2 ceramics. According to the analysis of XRD results, a pure TiO2 phase with a rutile structure can be found throughout the whole substitution range (0 ≤ x ≤ 0.02). Based on the refinement method, it is noted that the tetragonality firstly increase for 0 ≤ x ≤ 0.005, and then decreases for x > 0.005. A slight blue shift is observed for the A1g mode, whereas the Eg mode shows a red shift. The permittivity is highly dependent on the relative density, fc of Ti/(Mn0.5W0.5)-O1(1) and Ti/(Mn0.5W0.5)-O1(2) bond and Afc. The variation of quality factor strongly relies on the relative density, changing c/a value and valence state of Ti. The increase of c/a and elimination of Ti3+ contribute to the significant improvement of Q × f from 947 to 39,000 GHz. The τf dramatically decreases from 520 to 398 ppm/ºC because of the increase of unit cell volume. The excellent dielectric performance of Ti1-x(Mn0.5W0.5)xO2 ceramics can be achieved at x = 0.005 with εr = 105, Q × f = 39,000 GHz and τf = 464.4 ppm/ºC. [ABSTRACT FROM AUTHOR]

Electrode materials are key factors for supercapacitors to endow them with excellent electrochemical properties. Here, a novel hybrid structure of a CoSe/Co3O4-CNTs binder free composite electrode on nickel foam was prepared via a facile flame method, followed by an electrodeposition process. Benefitting from the synergetic effects of the multicomponent (with low resistances of 1.542 Ω cm2 and a moderate mesoporous size of 3.12 nm) and the enlarged specific surface area of the composite material (77.4 m2 g−1), the CoSe/Co3O4-CNTs composite electrode delivers a high specific capacitance of 2906 F g−1 at 5 mV s−1 with an excellent rate stability. The fabricated CoSe/Co3O4-CNTs/NF//AC ASC exhibits a high energy density of 43.4 Wh kg−1 at 0.8 kW kg−1 and a long cycle life (92.7% capacitance retention after 10,000 cycles). [ABSTRACT FROM AUTHOR]

The effects of LB glass on the sintering behavior, structure, and dielectric properties for the Ba3.75Nd9.5Ti17.5(Cr0.5Nb0.5)0.5O54 (BNTCN) ceramic were investigated. The results showed that the LB glass, as an effective sintering aid, successfully lowered the sintering temperature of BNTCN ceramic by formation of the liquid phase. Furthermore, the change of the structure and decrease in grain size had influences on the electrical conductivity, thermal stability, and microwave dielectric properties for the BNTCN ceramics doped LB glass. Finally, the excellent microwave dielectric properties with εr = 73.4, Q × f = 5277 GHz, and τf = +7.1 ppm/°C were obtained for samples sintered at 950°C when x = 5, indicating the BNTCN ceramic doped with 5 wt% LB glass is a promoting LTCC material. [ABSTRACT FROM AUTHOR]