CuO/ZnO/Al₂O₃ catalysts are commonly used for the methanol steam reforming reaction. The oxalate precursor of CuO/ZnO/Al₂O₃ catalysts were prepared via the co-precipitation method using oxalic acid as the precipitator, deionized water and ethanol as the solvent, and microwave radiation and water baths as aging heating methods, respectively. This suggests that ethanol selects the crystalline phase composition of oxalate precursors and limits their growth. Microwave irradiation prompted the isomorphous substitution between Cu²⁺ of CuC₂O₄ and Zn²⁺ of ZnC₂O₄ in the mother liquid; Zn²⁺ in ZnC₂O₄·xH₂O was substituted with Cu²⁺ in CuC₂O₄, forming the master phase (Cu,Zn)C₂O₄ in the precursor. Moreover, the solid solution Cu-O-Zn formed after calcination, which exhibited nano-fibriform morphology. It has the characteristics of small CuO grains, a large surface area, and strong synergistic effects between CuO and ZnO, which is conducive to improving the catalytic performance of methanol steam reforming. The conversion rate of methanol reached 91.2%, the space time yield of H₂ reached 516.7 mL·g⁻¹·h⁻¹, and the selectivity of CO was only 0.29%.

A wear prediction model is built to research the wear of the curved switch rail in a high-speed turnout. The Archard wear model is used in the wear prediction model to analyze the profile evolution law. The non-Hertzian contact Kik–Piotrowski method based on virtual penetration is used as the contact algorithm for the Archard wear model. A dynamic model of the vehicle–curved switch rail system based on the predicted profiles of the curved switch rail and the measured wheel profiles with different stages is established. The effect of the wheel and curved switch rail profiles’ wear on vehicle dynamic performance is analyzed. The results show that the wheel completely transitions from the stock rail to the curved switch rail between 35 and 50 mm head widths. As the head width of the curved switch rail increased, the position of the maximum wear depth gradually moved to the gauge shoulder. When the total passing weight of the train is 50 Mt, the 20 mm head width curved switch rail side wear reaches a maximum of 5.3 mm. The position in which the wheel transitions from the stock rail to the curved switch rail will be further away from the tip of the curved switch rail due to wheel–rail wear. Regarding the derailment coefficient, the wheel–rail vertical force and lateral force are both significantly impacted. However, they have little effect on the vertical and lateral acceleration of the vehicle. The wear of the wheels and rails has a higher impact on vehicle driving safety and a lower impact on vehicle driving stability.

The changes of the friction coefficient between wheel and rail affect the wheel‐rail adhesion characteristics of high‐speed trains. The adhesion state in the wheel‐rail contact area could be distinguished by the maximum friction coefficient between wheel and rail. The wheel‐rail adhesion is of great significance for high‐speed train traction. In order to study the influence of water, oil, fallen leaves, quartz sand, or their mixtures on the maximum friction coefficient between high‐speed wheel and rail, a wheel‐rail contact test bed is built to carry out the wheel‐rail contact test and wheel‐rail friction contact test. The comparative analysis of the test results shows that the axle load has little influence on the maximum friction coefficient between wheel and rail. Water, oil, and fallen leaves would reduce the maximum friction coefficient. Quartz sand could increase the maximum friction coefficient in a short time, while the excessive static friction coefficient would damage the wheel and rail. Besides, the maximum friction coefficient of water, oil, and fallen leaves mixing in pairs is lower than each of them existing alone. Both water and oil could increase the adhesion of quartz sand, and the effect of water is better. Therefore, when the sand still could not meet enough traction, it could be considered to add some water to increase the wheel‐rail adhesion.

Bistable energy harvesters have been extensively studied. However, theoretical research on the dynamics of bistable energy harvesters based on asymmetric bistable composite laminated plate and shell structures has not been conducted. In this paper, a theoretical model on the dynamics of an energy harvester based on an asymmetric bistable composite laminated shell is established. The dynamic snap-through, the nonlinear vibrations and the voltage output with two potential wells of the bistable energy harvester are studied. The influence of the amplitude and the frequency for the base excitation on the bistable energy harvester is studied. When the frequency for the base excitation with a suitable amplitude in the frequency sweeping is located in a specific range or the amplitude for the base excitation with a suitable frequency in the amplitude sweeping is located in a specific range, the large-amplitude dynamic snap-through, nonlinear vibrations and voltage output with two potential wells can be found to occur. The amplitude and the frequency for the base excitation interact on each other for the specific amplitude or frequency range which migrates due to the softening nonlinearity. The vibration in the process of the dynamic snap-through behaves as the chaotic vibration. The nonlinear vibrations of the bistable system behave as the periodic vibration, the quasi-periodic vibration and the chaotic vibration. This study provides a theoretical reference for the design of energy harvesters based on asymmetric bistable composite laminated plate and shell structures.

Air-rib tents are widely used because they are lightweight and site adaptable, but the large deformation of these tents reduces their effective space. It is important to reduce the displacement of the air-rib tent by parameter optimization. The influences of external factors on the tent are studied in this paper. Four parameters of the tent’s wind ropes are the angle of the wind ropes, the number of the wind ropes, and the initial prestress of the wind ropes on the side or end faces. The influence of the angle of the wind ropes and the number of the wind ropes on the displacement is larger than the other two parameters. The closer the wind ropes are to the center of the tarpaulin, the greater the displacement of the tent. Based on an analysis using response surface methodology, the optimal parameters are as follows: the angle of the wind ropes is 41°, the number of the wind ropes on the side is two, the initial prestress of the wind ropes on the end face is 800 Pa, and the initial prestress of the wind ropes on the side is 0 Pa. Under these optimal parameters, the maximum displacement decreases by 10.2%, and the maximum stress barely changes.