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Spin–orbit torque (SOT) has been considered as one of the promising technologies for the next-generation magnetic random access memory (MRAM). So far, SOT has been widely utilized for inducing various modes of magnetization switching. However, it is a challenge that so many multiple modes of magnetization switching are integrated together. Here we propose a method of implementing both unipolar switching and bipolar switching of the perpendicular magnetization within a single SOT device. The mode of switching can be easily changed by tuning the amplitude of the applied current. We show that the field-like torque plays an important role in switching process. The field-like torque induces the precession of the magnetization in the case of unipolar switching, however, the field-like torque helps to generate an effective z-component torque in the case of bipolar switching. In addition, the influence of key parameters on the mode of switching is discussed, including the field-like torque strength, the bias field, and the current density. Our proposal can be used to design novel reconfigurable logic circuits in the near future.

The hot fuel gas generating with solid fuel was introduced to an opposing jet thermal protection system(TPS), saving the occupied space and reducing the weight of the gas supply system. In this study, the thermal protection performance of opposing jet TPS with hot fuel gas is investigated. The surface heat flux is initially obtained by solving the Reynolds-average Navier-Stokes(RANS) equations coupled with the Menter’s shear stress transport (SST) model. Then, the obtained heat flux is loaded to the blunt body to solve the temperature distribution. The influence of the hot fuel gas on the opposing jet TPS was analyzed with different flying condition. Results show that the hot fuel gas reduces the insulating capacity of the opposing jet, but the peak heat flux exhibits a prominent reduction in contrast to that without injection. The surface temperature also reduces a lot even the hot fuel gas is adopted than that without injection. To obtain a good cooling efficiency, the jet pressure is enhanced. With a higher jet pressure, the surface heat flux, as well as the surface temperature, is reduced, and the similar cooling efficiency can be obtained compared to that with normal coolant.

The three-dimensional Navier—Stokes equation and the k− viscous model are used to simulate the attack angle characteristics of a hemisphere nose-tip with an opposing jet thermal protection system in supersonic flow conditions. The numerical method is validated by the relevant experiment. The flow field parameters, aerodynamic forces, and surface heat flux distributions for attack angles of 0°, 2°, 5°, 7°, and 10° are obtained. The detailed numerical results show that the cruise attack angle has a great influence on the flow field parameters, aerodynamic force, and surface heat flux distribution of the supersonic vehicle nose-tip with an opposing jet thermal protection system. When the attack angle reaches 10°, the heat flux on the windward generatrix is close to the maximal heat flux on the wall surface of the nose-tip without thermal protection system, thus the thermal protection has failed.