- by Jaspreet Singh, Nitish Kumar Gupta and Subhendu SarkarFerrell and Berreman modes, arising from radiative bulk plasmon-polariton and phonon-polariton excitations, are absorption resonances in thin metal films and polar-dielectric media. These modes characterized by volume charge oscillations and epsilon-near-zero (ENZ) characteristics offer unique lightāmatter interaction pathways and have thus garnered extensive research interest. Here, we demonstrate nanoporous goldāsilver (NPGS) films as a versatile platform for realizing FerrellāBerreman (FB) random metasurfaces with thickness-dependent ENZ response control. Experimentally, we extract the effective optical constants of NPGS films with varying thicknesses, […]
- by Yang Meng, Mingbin Peng, Zhizhou Li, Jialong Liu, Wenyong Jin and Yongsheng WangThis study combines experimental diagnostics and two-dimensional (2D) numerical simulations to elucidate the establishment mechanisms of atmospheric pressure glow discharge (APGD) channels under high-frequency AC voltage. Experimental investigations employing a needle-plate electrode configuration and a resonant power supply revealed two distinct discharge modes: unipolar, characterized by plasma formation exclusively during negative half-cycles, and bipolar, involving dual-channel development in both half-cycles. Numerical simulations based on fluid equations coupled with Poisson and photoionization models demonstrated that under the action of multiple cycles […]
- by Kai Chen and Xue-Feng WangWe investigate the site dependent effects of substitutional phosphorus doping on the geometric structure, electronic properties, magnetic properties, and transport characteristics of penta-SiC2 nanoribbons (NRs) using the density functional theory combined with non-equilibrium Greenās functions. Phosphorus doping can introduce atomic spin polarization and usually results in an antiferromagnetic (AFM) ground state at C sites, where the spin polarizations in any two neighbor primitive cells are oppositely orientated. Nevertheless, the energetic difference between the AFM and ferromagnetic (FM) states are small […]
- by Xuanchang Zhang, Haotian Zeng, Hui Jia, Xueying Yu, Suguo Huo, Makhayeni Mtunzi, Huiwen Deng, Jaeseong Park, Hexing Wang, Alwyn Seeds, Huiyun Liu and Mingchu TangHeteroepitaxial growth of Si-based semiconductor materials has become an efficient method for high-performance group-IV and IIIāV optoelectronic and electronic devices. As-manufactured epi-ready Si wafers frequently retain molecular residues even after high-temperature thermal deoxidation. Consequently, additional surface conditioning can be required to achieve the cleanliness and morphology necessary for high-quality epitaxial growth. This study evaluates the effectiveness of Ar plasma pre-treatment for surface preparation of Si substrates, which is used as a platform for heteroepitaxial growth of group-IV and IIIāV materials […]
- by L Esteve, R Mata, O Monerris, C Alcaide, C Miquel and V E BoriaDielectric materials are increasingly common in modern satellite payloads due to their advantageous properties, such as the large mass and volume reduction can be achieved when they are used in radiofrequency (RF) equipment. However, the presence of dielectric materials in the output high-power section of RF payloads requires careful study of their influence on the multipactor performance, and therefore, their secondary electron emission yield (SEY). This characterization in dielectrics is nowadays a challenging and time-consuming practice relying on the electrical […]
- by Yun Geng, Xiaofei Yao, Hannan Shan, Minju Xu, Jiangang Ding, Yingsan Geng and Zhiyuan LiuThis study presents a systematic investigation into the prestrike characteristics of double-break vacuum circuit breakers under various DC voltage levels, focusing on the impact of different resistorācapacitor (RC) hybrid grading configurations. Experimental evaluations were conducted to analyze the distribution and dispersion of prestrike gaps, floating terminal voltages, and voltage-sharing uniformity across five RC schemes. Compared to traditional capacitive grading, RC hybrid methods considerably improve the voltage distribution symmetry, enhance the low-voltage side voltage proportion, and reduce the dispersion of prestrike […]
- by Peng Zhang, Huaqing Guan, Ziyan Tan, Xiaonan Zhang, Jinhua Hao, Xi Li and Xianxiu MeiThe formation of helium (He)-induced fuzz is one of the critical challenges that must be addressed for the long-term service of plasma-facing materials in fusion reactors. Refractory high-entropy alloys, represented by NbMoTaW, have emerged as promising candidates in fusion applications due to their notable phase stability and irradiation resistance. However, the specific mechanisms by which compositional variations affect He behavior and the evolution of surface nanostructures remain unclear. This study systematically investigated the influence of compositional heterogeneity on He-induced fuzz […]
- by Huan Zheng, Haoran Wang, Jinyu Zhang, Yongsen Han and Zhonghua LiEpoxy resin (EP) is widely used in gas-insulated switchgear (GIS) due to its excellent mechanical and insulation properties. However, surface flashover on epoxy caused by charge accumulation at the gas-solid interface under DC electric field significantly threatens the reliability of GIS. In this study, a series of epoxy composites were prepared using 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (6FAP) as a fluorinated component to modify the epoxy system. The surface flashover characteristics were investigated under both air and SF6 conditions. Experimental results show that, […]
- by Atsushi Komuro, Yoshiyuki Teramoto and Hyun-Ha KimPulse-controlled atmospheric-pressure streamer discharges have attracted attention as an effective source of plasma for applications such as selective oxidation, sterilisation, and nitrogen fixation. However, our understanding of how the voltage waveform parameters consistently and quantitatively influence the production of reactive radicals remains limited. In this study, we performed 70 two-dimensional fluid simulations of streamer discharges in a needle-to-plane geometry by systematically varying the peak voltage (15ā40 kV), voltage rise time (1.9ā45.9 ns), and pulse width (8.5ā193.9 ns). For each case, […]
- by Nikita MedvedevUnderstanding the non-equilibrium behavior of stainless steel under extreme electronic excitation remains a critical challenge for laser processing and radiation science. We employ a hybrid framework integrating density-functional tight binding, transport Monte Carlo, and Boltzmann equations to model austenitic stainless steel (Fe0.5875Cr0.25Mn0.09Ni0.07C0.0025) under ultrafast irradiation. The developed approach uniquely bridges atomic-scale electronic dynamics and mesoscale material responses, enabling the quantitative mapping of electron-temperature-dependent properties (electronic heat capacity, thermal conductivity, and electronāphonon coupling) up to the electronic temperatures Teā¼ 25 000 […]
- by Li Chen, Jiakuo Shi, Hongping Wu, Maoyou Yang, Junmei Wang and Zhishan MiThe paper investigates the modulation of interface contact and electronic properties by external vertical strains and electric fields in graphene/WS2 van der Waals heterostructure (vdWH) using first-principles calculations. The results reveal that the graphene/WS2 vdWH exhibits an equilibrium interlayer spacing of 3.40 Ć . Both interlayer spacing adjustments and external electric fields can effectively induce charge transfer between graphene and WS2 monolayer, enabling tunability of the Schottky barrier height. Specifically, a positive electric field facilitates charge transfer from graphene to WS2, […]
- by Kun Wang, Wei Xia, Ximao Zhong, Kai Tang, Zuojia Liao and Shuling HuVibration-driven wind energy harvesters (WEHs) are much eco-friendly than wind turbines because of their quiet and safe operation for surrounding humans and animals. However, the low energy harvesting efficiency limits the wide application of vibration-driven WEHs. The present study designs a flutter-driven WEH based on the decoupling structure between bending and twisting stiffnesses, which produces predictable violent oscillation in the wind. The WEH electromechanical coupling model considering the aeroelastic effects is established based on the Hamiltonian principle. The effects of […]
- by Haotian Zheng, Zihan Sun, Xinlei Zheng, Jiabao Tang, Zheng Zhao and Jiangtao LiDischarge plasma, grounded in non-equilibrium reaction pathways, offers the theoretical potential for fast and efficient chemical synthesis, particularly in nitrogen fixation via air plasma. However, the efficient generation of target products remains a central challenge in practical applications, due to the presence of numerous complex and unavoidable parasitic reactions within the plasma. In this study, a novel three-electrode structure was employed to control NOx production through hybrid pulse/radio frequency (RF) plasma. Through plasma emission images, it was observed that an […]
- by Jinji Sun, Hanmou Wang, Jianyi Ren, Daiyong Chen, Haofan Wang and Weiyong ZhouMagnetic shielding devices isolate the geomagnetic field with high-permeability soft magnetic materials. Researchers adopted an external compensation method to further reduce the static residual field. A common method is to apply a continuous DC compensation magnetic field outside the shielding layers to offset the geomagnetic field. The active approach aims to create a weak magnetic field environment. The prolonged intervention of the DC compensation system raises the energy consumption and increases the instability factors of the residual field. In this […]
Mass spectrometry websites, social media, journal feeds, and other links and items of interest to the mass spectrometry community.
