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In order to solve the problem of multiple failures of the oil collecting box connecting pin of the arc gear toothed when the 1580 mm hot strip mill F2 rolling mill was rolling the thin plate,several field tests were performed on the F2 rolling mill drive system and roll system,and the test signal was processed in time domain and frequency domain. The three-dimensional finite element model of rolling mill was built to simulate the natural frequency of the vibration,including main drive system,roller system and frame. The calculated results are basically consistent with the test results. It can be determined that the mill unit has a resonance and the dominant frequency corresponds to the maximum vibration displacements are found at the side of the gear box,providing an effective reference for further analysis of the mill vibration characteristics and causes.

The full tooth dynamic finite element model of the GIICL9 crown gear coupling is established based on the ANSYS/LS-DYNA.The research results demonstrate that,the impact phenomenon need to be controlled in the start-up process,and the contact stress distribution along the high direction of the tooth is not uniform.In addition,the average contact stress value of each tooth is also different.The smaller of the tool displacement circle radius,the more discrete the contact stress of each tooth.The maximum mises stress of tooth root and contact stress tooth surfaces will not be affected by the rotational speed as the running process is stable.

Flexible wearable sensors with high sensitivity, broad sensing range, and low detection accuracy have great potential applications in human motion online monitoring, human healthcare detection, and human–machine interface. However, high sensitivity and broad sensing range conflict, as the former requires conspicuous structural changes under microstrain while the latter requires complete morphology under large deformation. Herein, we report few-layer 2D Ti3C2Fx and 1D polypyrrole (PPy) nanowires with a sandwich stack structure transfer on polyacrylic acid (PAA) tape based on layer-by-layer (LBL) assemble technology. The 1D PPy nanowires enhance the strain sensor's interfacial adhesion and electron transmission channel, resulting in high sensitivity and a permissible detection range (0–50%). Under various applied force stimuli, the synergetic effect of Ti3C2Fx nanosheets (4.72 nm thickness) and PPy nanowires (diameter 20–50 nm) endows the stack structure with good electrical–mechanical performance, which is reflected by the sensor's high sensitivity (GF = 2950, ε = 50%; GF = 475, ε = 10%; GF = 22, ε = 0.1%). Such a flexible sensor with a permissible detection range (up to 50%), a low detection limit (0.1%), and reliable repeatability (>1500 cycles) has potential applications for human motion detection, clinical diagnosis, and healthcare monitoring. [ABSTRACT FROM AUTHOR]

Photoreduction of CO2 into CO, CH4 or hydrocarbons is attractive, due to environmental compatibility and economic feasibility. Optimizing the reaction engineering of CO2 reduction is an effective and general strategy that should be given special consideration. In this article, the photocatalytic CO2 reduction performances are originally investigated in a low vacuum in both dilute (10%) and pure CO2. We discover that the CH4 yield increased above one hundred times as the vacuum degree increased from barometric pressure to −80 kPa in dilute CO2. It also reveals long-term stability and good cycling performance in a low vacuum. The enhanced CO2 photoreduction performance in a low vacuum comes from better accumulation of photogenerated electrons, less intense Brownian movement of gas molecules in the environment and hindrance of the active site-blocking of gas molecules in the environment. Improved photocatalytic CO2 reduction in a low vacuum is further verified by Pt–TiO2 catalysts. This research presents a general route for producing clean fuels by photocatalytic CO2 reduction in a more effective way. [ABSTRACT FROM AUTHOR]

In recent years, the problem of urban traffic congestion has become increasingly prominent. In this study, an intelligent traffic signal model based on open source road traffic information was proposed. We used real-time traffic data provided by Gaode open platform to model urban traffic congestion of direction road segments, single intersections and adjacent multiple intersections. And based on these models and fuzzy control theories, the intelligent signal cycle model and intelligent signal timing model was established. The simulation results of Vissim software show that the model is superior to the fixed-time signal control system, the effect in the severe congestion period is better than the general congestion period, and the maximum can shorten the road network queue time by 29.99%. This research will help ease urban traffic congestion and can be applied to heavily congested cities. [ABSTRACT FROM AUTHOR]