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Abstract In this article, a three‐dimensional polarisation‐rotation surface (PRS) with reflective filtering response based on two orthogonally inserted coupled slot‐line is investigated, which can reflect a vertically/horizontally polarised incident wave by 90°. Each unit cell of the PRS is composed of a pair of meandered slot‐line sections with open‐short‐ends etched on the vertically and horizontally inserted single‐layer printed circuit boards. Under the incidence of a linearly polarised plane wave along the vertical/horizontal direction, the plane wave is converted into the guided wave by the open‐circuited end of the slot‐line section, and then the guided wave is obstructed by the short end of the slot‐line section and coupled to the other slot‐line section, thus leading to 90° polarisation rotation. To simplify the design procedure, a matrix coupling theory is applied to synthesise and design the proposed PRS. A sample with fractional bandwidth of 20% at the centre frequency of 5 GHz and return loss of 20 dB is designed, fabricated, and measured for verification. The measured and simulated results are in good agreement with the theoretical ones. The results confirm that the proposed PRS has low insertion loss, high polarisation conversion ratio, and stable filtering performance for oblique incident angle up to 60°.

In this article, a polarization rotation transmissive surface (PRTS) of arbitrary angle based on a three-dimensional (3-D) frequency selective structure is proposed. The PRTS unit cell is composed of three parallel-coupled slotline sections with open-short ends etched on vertically and horizontally inserted single-layer printed circuit boards (PCBs). Under the incidence of vertically polarized waves, the spatial waves are converted into guided waves by the open-circuited end of one slotline section, and then the guided waves are coupled to two other slotline sections that can act as two independent coupling transmission paths in the orthogonal planes. This can be observed as a power divider, and the power division ratio can be fully controlled by virtue of the coupling strengths of the two coupling transmission paths. Thus, the polarization of incidence waves can be rotated at an arbitrary angle at the output port. To simplify the design procedure, a filtering power division theory and an equivalent circuit model are first used to obtain the theoretical response. Subsequently, a coupling matrix is employed to synthesize and design the proposed PRTS. To confirm the effectiveness of the proposed PRTS, two examples with different polarization rotation angles and fractional bandwidths at the same center frequency of 5 GHz and return loss of 20 dB are designed, fabricated, and measured. The measured results confirm our theoretical predictions and agree with the simulated results, thus demonstrating that the proposed PRTS exhibits stable frequency response under a large oblique incidence, in addition to their easiness in fabrication.

To improve the defense capability of military equipment under extreme conditions, impact-resistant and high-energy-consuming materials have to be developed. The damping characteristic of entangled porous metallic wire materials (EPMWM) for vibration isolation was previously investigated. In this paper, a study focusing on the impact-resistance of EPMWM with the consideration of ambient temperature is presented. The quasi-static and low-velocity impact mechanical behavior of EPMWM under different temperatures (25 °C–300 °C) are systematically studied. The results of the static compression test show that the damping energy dissipation of EPMWM increases with temperature while the nonlinear damping characteristics are gradually enhanced. During the impact experiments, the impact energy loss rate of EPMWM was between 65% and 85%, while the temperatures increased from 25 °C to 300 °C. Moreover, under the same drop impact conditions, the overall deformation of EPMWM decreases in the temperature range of 100 °C–200 °C. On the other hand, the impact stiffness, energy dissipation, and impact loss factor of EPMWM significantly increase with temperature. This can be attributed to an increase in temperature, which changes the thermal expansion coefficient and contact state of the internal wire helixes. Consequently, the energy dissipation mode (dry friction, air damping, and plastic deformation) of EPMWM is also altered. Therefore, the EPMWM may act as a potential candidate material for superior energy absorption applications.

In this work, we adopt a low-temperature sustainable plasma treatment approach for the fabrication of ferroelectric memory devices. From our experimental results, we found that the ferroelectric polarization characteristics of HfAlO _x ferroelectric device could be further improved by using low-temperature nitrogen plasma treatment on bottom TiN electrode for surface modification. The low-temperature nitrogen plasma treatment on TiN bottom electrode not only prevent electrode oxidation, but also lowers the generation of defect traps at the interface between ferroelectric HfAlO _x and TiN bottom electrode during high-temperature ferroelectric annealing process. Besides, the nitrogen-treated bottom electrode also can improve bias-stress induced instability and cycling endurance of HfAlO _x ferroelectric devices due to the effective suppression of randomly distributed defect traps or oxygen vacancies near the surface of bottom electrode.

The purpose of this study was to examine plasma-activated buffer solution (PABS) and plasma-activated water (PAW) combined with ultrasonication (U) treatment on the reduction of chlorothalonil fungicide and the quality of tomato fruits during storage. To obtain PAW and PABS, an atmospheric air plasma jet was used to treat buffer solution and deionized water at different treatment times (5 and 10 min). For combined treatments, fruits were submerged in PAW and PABS, then sonicated for 15 min, and individual treatment without sonication. As per the results, the maximum chlorothalonil reduction of 89.29% was detected in PAW-U10, followed by 85.43% in PABS. At the end of the storage period, the maximum reduction of 97.25% was recorded in PAW-U10, followed by 93.14% in PABS-U10. PAW, PABS, and both combined with ultrasound did not significantly affect the overall tomato fruit quality in the storage period. Our results revealed that PAW combined with sonication had a significant impact on post-harvest agrochemical degradation and retention of tomato quality than PABS. Conclusively, the integrated hurdle technologies effectively reduce agrochemical residues, which helps to lower health hazards and foodborne illnesses.