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To solve the display distortion caused by the motor rotational speed changes in the long-term operation of the rotating LED multi-sector display system, the model for LED multi-sector stable display (MSSD) in variable rotational speed is proposed based on the principle of visual persistence. The stepping motor subdivision driving technology is applied to the rotating LED multi-sector display, and the equal precision frequency measurement method is used for accurate rotational speed measurement. Then the innovation adaptive kalman filter (IAKF) is researched to further enhance the robustness to eliminate noise pollution, and the relationship between the modification value caused by rotational speed and the LED linear array minimum refresh time is analysed. The rotating LED MSSD system based on LED linear array rotated by stepping motor is provided. The test results reveal the relationship between rotational speed and the LED linear array minimum refresh time, and show that the lighting position of the LED can be synchronized with the lighting state during the rotational speed fluctuation, and the error can be controlled to a low level via LED linear array minimum refresh time correction. The designed model can effectively eliminate the distortion of the rotating LED multi-sector display screen caused by the changes of the motor rotational speed, and has a very stable display effect.

The development of room temperature NH3 sensors with flexible substrate can fulfill the future demands of high NH3 sensing performance under the premise of lower energy consumption and safety circumstance in wearable electronics field. The polyaniline and a serious of WO3 hollow spheres@ polyaniline hybrid were successfully synthesized via a combined route of simple hydrothermal method and in-situ chemical oxidative polymerization. The room temperature NH3 sensors were fabricated by assembling WO3 hollow spheres@ polyaniline hybrid on flexible polyethylene terephthalate (PET) films. The NH3 sensing properties of the fabricated devices demonstrated that the device utilizing 10 mol% WO3 hollow spheres@ polyaniline (PAWHs 10) hybrid exhibited the best sensing performance to 100 ppm NH3 (response value at 25) at 20 °C. Moreover, the PAWHs10 hybrid sensor also achieved excellent NH3 selectivity, ppb-level detection limit (1.67–500 ppb NH3), and good response/recovery rates (136 s/130 s) at 20 °C. The enhanced sensing performance of incorporation of polyaniline and WO3 hollow spheres was mainly attributed to the hollow structure of WO3 and the formation of p-n heterojunction between PANI and WO3 hollow spheres.

The seismic performance of rounded rectangular hollow tall piers, applied popularly in railway bridges in high-intensity areas in China, has rarely been investigated till now. The current seismic design approaches mostly stem from short-to-medium solid columns whose seismic behavior is different from those of hollow members. According to cyclic tests in publications, there are also obvious differences in the seismic performance between the rounded rectangular hollow piers and the common hollow ones. To clarify the differences among them and update the existing design approach, the damage modes and dynamic responses of rounded rectangular hollow columns under different-level earthquakes should be studied comprehensively. Therefore, three 1/6-scale models from a 40 m prototype pier were tested using a 10.1 m × 8.1 m 6DOFs shaking table. The experimental outcomes were analyzed and compared with those previous semistatic tests. The results showed that the three specimens underwent flexural damage with horizontal cracks distributing along the whole body. Moreover, a second plastic hinge region, evidenced by the denser flexural cracks around the middle part, appeared in addition to the lengthened plastic hinge close to the pier footing. These findings are mainly attributed to the combined influence of the variable hollow section and higher-order effects, which differs greatly from the damage behaviors of specimens under cyclic loads. As expected, the increased stirrup ratio produced great improvement in the seismic performance of rounded rectangular hollow tall piers (DB1 and DB2), while fewer stirrups corresponded to a decrease in ductility (DB3).