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High-entropy alloys (HEAs), recently emerging alloys with numerous excellent mechanical performances, may have a wide application prospect in impact engineering. The ballistic impact response of Fe40Mn20Cr20Ni20 HEA was investigated under various loading conditions. Ballistic impact tests with spherical projectiles and 87 type 5.8 mm small caliber bullets (DBP87 bullets) were conducted on 10 mm thick Fe40Mn20Cr20Ni20 HEA plates with varying impact velocities, compared with 20Mn23AlV steel (high manganese low magnetic steel). The relationship between microstructural details and aspects of ballistic behavior governing performance was established through experimental explorations and theoretical models. According to the findings, dense dislocation structures led to distinguishing work hardening in the HEA, and the strain-hardening capacity of the HEA enhanced dramatically with increasing strain rate under dynamic tension. Meanwhile, under 500 m/s impact velocity, twinning and microbanding had outstanding strain-hardening capabilities for the current HEA, and the cooperation of the dislocation slip and stacking faults was critical for strain hardening in the HEA when the impact velocity was increased to 930 ± 15 m / s , whereas only a small amount of dislocation sliding and twinning occurred during the dynamic deformation process of 20Mn23AlV steel at different impact velocities. These findings demonstrated that the outstanding strain-hardening capabilities of Fe40Mn20Cr20Ni20 HEA made it a promising candidate for ballistic impact engineering compared with 20Mn23AlV steel. [ABSTRACT FROM AUTHOR]

Energy shortage has always been a problem that the world needs to face. The combined cooling, heating, and power (CCHP) system, as a multi-level energy utilization system that can provide cooling, heating, and electric energy simultaneously, is considered to have good development prospects in alleviating energy problems. In addition, because of the rapid development of electric vehicles (EVs), using EVs as power supply devices has become a hot topic of research. In this paper, EVs are combined with the CCHP system as new power supply equipment, and the influence of the season on the user's cooling, heating, and power demand is considered. Aiming at the minimum economic cost, the system is optimized by using the PSO algorithm in two operating modes: following electricity load (FEL) and following thermal load (FTL). The final results show that the participation of EVs can reduce costs in both operating modes, especially in FTL mode, which can reduce costs by 4.58%, 13.61%, 12.74%, and 3.57% in spring, summer, autumn, and winter, respectively. In addition, the FEL mode is more economical in spring and winter, and the FTL mode is more economical in summer and winter. In addition, the C O 2 emissions in FEL mode are always less than in FTL mode. [ABSTRACT FROM AUTHOR]

Highlights: [•] Whole mathematical model of Vibration Isolation System (VIS) in DRLG IMU is built. [•] An effective design method of VIS based on motion decoupling is proposed. [•] Six degree of freedom (DOF) model of VIS is decoupled into six one DOF models. [•] Stiffness and damping parameters are optimized to meet the precision requirement. [•] A veritable VIS used in DRLG POS is developed as an instance. [ABSTRACT FROM AUTHOR]

The pursuit of strong and ductile synergy is a key objective in the development of metals and alloys. Medium entropy alloys (MEAs) have emerged as a highly promising structural material, with potential applications in high-speed trains, aerospace, and defense fields. This study systematically investigates the effect of annealing temperature on the mechanical properties of a CrCoNi based MEA, namely (CrCoNi) 97 Al 1 Ti 2 MEA. The (CrCoNi) 97 Al 1 Ti 2 MEA was fabricated by cold rolling reduction of 40% and subsequently annealed at 820 ℃ for 1 h to achieve a heterogeneous structure that exhibits an excellent combination of strength and plasticity. Scanning electron microscopy and transmission electron microscopy were used to characterize the samples before and after tensile deformation, and to reveal the underlying deformation mechanisms. The results show that annealing at 820 ℃ for 1 h introduces a large number of precipitation phases, which are not observed at other annealing temperatures. During plastic deformation, the fine recrystallized grains contribute to the good ductility of the (CrCoNi) 97 Al 1 Ti 2 MEA, while deformation twinning and dislocation densities enable it to maintain good strength. The precipitation phase formed by annealing at 820 ℃ also significantly improves the strength of the (CrCoNi) 97 Al 1 Ti 2 MEA. Overall, this study provides insights into the mechanical properties of (CrCoNi) 97 Al 1 Ti 2 MEA, and highlights the importance of annealing temperature in achieving an optimal combination of strength and plasticity. The findings of this study have important implications for the design and development of MEAs for various applications in structural engineering. [Display omitted] • The (CrCoNi) 97 Al 1 Ti 2 MEA with a heterogeneous structure and nanoprecipitate phases was successfully fabricated through a cold rolling reduction of 40% followed by annealing at 820 ℃ for 1 h. • The heterogeneous-structured (CrCoNi) 97 Al 1 Ti 2 MEA exhibits an excellent combination of strength and plasticity after annealing at 820 ℃ for 1 h. • The (CrCoNi) 97 Al 1 Ti 2 MEA demonstrates good ductility during plastic deformation due to the fine recrystallized grains. The significant increase in strength of the (CrCoNi) 97 Al 1 Ti 2 MEA is primarily attributed to grain refinement, dislocation densities, and precipitation phases introduced by cold rolling and annealing. [ABSTRACT FROM AUTHOR]

As an electroluminescentdevice, the coupling relationship between light-emitting diode (LED) input currents, optical power, and LED junction temperature is a complicated multiphysics process. In this paper, a simplified LED photoelectron-thermal (PET) model by artificial neural network (ANN), which can translatemultiphysics field issue into a singlephysics field problem, ismentioned to study the coupling relationship. In the first, an LED lumens, optical power, and electric power at different temperatures are monitored in a temperature controlling integrating sphere. Then, a backpropagation (BP) ANN is trained by these data to construct an LED Photo-Electron-Thermal (PET) relationship. In addition, LED luminaire thermal analyzing is performed using a finite-element method on the outputs of the BP ANN. Finally, the advantage of this method in terms of saving computing resources and computing time is analyzed by comparing the degrees of freedom in different models. The result shows that at least 6.7 times computing resource are saved by this method, which will reduce the LED thermal management system analyzing time greatly. Finally, the application and extension of this model are discussed. [ABSTRACT FROM PUBLISHER]