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Electromagnetic spring active isolators have attracted extensive attention in recent years. The standard Bouc-Wen model is widely used to describe hysteretic behavior but cannot accurately describe asymmetric behavior. The standard Bouc-Wen model is improved to better describe the dynamic characteristic of a toothed electromagnetic spring. The hysteresis model of toothed electromagnetic spring is established by adding mass, damping, and asymmetric correction terms with direction. Subsequently, the particle swarm optimization algorithm is used to identify the parameters of the established model, and the results are compared with those obtained from the experiment. The results show that the current has a significant impact on the dynamic curve. When the current increases from 0.5 A to 2.0 A, the electromagnetic force sharply increases from 49 N to 534 N. Under different excitations and currents, the residual points predicted by the model proposed in this work fall basically in the horizontal band region of -20-20 N (for an applied current of 1.0 A) and -40-80 N (for an application of 4.5 mm/s). Furthermore, the maximum relative error of the model is 12.75%. The of the model is higher than 0.98 and the highest value is 0.9993, proving the accuracy of the established model.
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http://dx.doi.org/10.3390/ma16134889 | DOI Listing |
Micromachines (Basel)
August 2025
School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen 361024, China.
For ultra-low-frequency vibration applications, this study focuses on a piezoelectric energy harvesting system with a spring mass system, utilizing magnetic plucking to up-convert the frequency. The proposed spring mass system includes a spring, a magnet mass with a guide rail, and a fixed pulley. The spring mass system responds to external ultra-low-frequency excitation and transfers the vibration to the piezoelectric cantilever beam through the magnets, achieving frequency up-conversion.
View Article and Find Full Text PDFSensors (Basel)
August 2025
Institute of Transport, Faculty of Mechanical Engineering, VSB-Technical University of Ostrava, 17. listopadu 2172/15, Poruba, 708 00 Ostrava, Czech Republic.
Vibrating feeders are used to empty bulk materials from storage bins, to feed and dispense materials into weighing bins or dispensers, or to feed materials evenly and smoothly into downstream equipment. The harmonic oscillation of the trough can be provided by an electromagnetic oscillator, which consists of an electromagnet consisting of a core and a coil with a given number of coil turns and armature. The aim of this paper has been to verify whether the working condition of the vibrating feeder, i.
View Article and Find Full Text PDFCells
August 2025
School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450052, China.
Spring low temperatures are a serious natural threat to wheat production in the Huang-Huai wheat region, and they are often accompanied by weak light environments during the day. To elucidate the response patterns and adaptation mechanisms of winter wheat leaves to low-temperature and weak-light environments, we simultaneously measured prompt chlorophyll a fluorescence, delayed chlorophyll a fluorescence, and modulated 820 nm light reflection; moreover, we analyzed the effects of low temperature and weak light treatment for different duration (2 h and 4 h) on the donor-side activity of photosystem II (PSII), the degree of PSII unit dissociation, the efficiency of light energy absorption and capture by PSII, electron transfer to Q and PSI terminal, PSI activity and cyclic electron transport activity in isolated wheat leaves under controlled conditions. The results, which were corroborated using the three methods, revealed that in low-temperature and weak-light environments, the degree of PSII unit dissociation, and the efficiency of light energy absorption, capture, and electron transfer to Q decreased, while the donor-side activity remained unaffected.
View Article and Find Full Text PDFJ Photochem Photobiol B
October 2025
Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland. Electronic address:
Diffused light and sunflecks within the crop canopy cause rapid changes in light intensity, which decrease photosynthetic productivity. Under water deficit conditions, the negative effect of light variability on photosynthetic performance can be further aggravated. The differentiation in the response of the youngest fully developed and older leaves of barley varieties to simulated drought was evaluated under fluctuating light.
View Article and Find Full Text PDFPeerJ
August 2025
Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, School of Physics and Optoelectronic Engineering, Foshan University, FoShan, Guangdong, China.
Pitaya is a high-value perennial tropical fruit known for its nutritional and health benefits. It is now widely cultivated in many tropical and subtropical countries, offering strong economic returns. China ranks first globally in pitaya cultivation, which includes both open-field production in tropical and subtropical regions and facility-based cultivation in temperate zones.
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