bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iterative extraction of overtones from black hole ringdown
Authors: Takahashi Kazuto , Motohashi Hayato 
Published: August 2024

Abstract
Extraction of multiple quasinormal modes (QNMs) from ringdown gravitational waves emitted from a binary black hole coalescence is a touchstone to test whether a remnant black hole is described by the Kerr spacetime in general relativity. However, it is not straightforward to check the consistency between the ringdown signal and the QNM frequencies predicted by the linear perturbation theory. While the longest-lived mode can be extracted in a stable manner, the higher overtones damp more quickly and hence the fitting of overtones tends to end up with the overfit. To improve the extraction of overtones, we propose an iterative procedure consisting of fitting and subtraction of the longest-lived mode of the ringdown waveform in the time domain. Through the analyses of the mock waveform and numerical relativity waveform, we clarify that the iterative procedure allows us to extract the overtones in a more stable manner.
Discharge fault type identification of C4F7N/CO2/O2 mixed insulating gas for engineering based on product components
Authors: Cui Guangkai , Wang Cong , Yang Yuan , Wang Hao , Tu Youping , Zheng Zhong , Jin Hua 
Published: August 2024

Abstract
Perfluoroisobutyronitrile (C4F7N) gas mixture is considered one of the most promising alternative gases for SF6 due to its excellent environmental protection and insulation performance. At present, the Shanghai region of China has adopted 8.5% C4F7N-86% CO2-5.5% O2 proportion gas mixture as the insulation medium for 126 kV gas insulated switchgear and has put it into practical engineering application. This paper conducted decomposition experiments on the proportion gas mixture under spark discharge, suspension discharge, and corona discharge conditions, respectively. The composition analysis of the decomposition products was carried out using a gas chromatography mass spectrometry and a gas chromatography-pulsed discharge helium ionization detector, which got decomposition products of the C4F7N/CO2/O2 gas mixture under discharge faults mainly include CO, CF4, C3F8, C4F8, C3F6, and CF3CN. According to the decomposition path of the C4F7N gas mixture, this paper selected three primary decomposition products (CO, CF4, C3F8) and one secondary decomposition product (C4F8) for the correlation characterization of discharge types, and proposed the ratios of c(CO)/c(CF4) and c(C4F8)/c(C3F8) as the characteristic quantities to characterize the different discharge types. Finally, in order to accurately identify the C4F7N/CO2/O2 gas mixture discharge type, this paper chose the decision tree algorithm to build a identification tree. The final identification result indicates that the ratio of c (CO)/c (CF4) and c (C4F8)/c (C3F8) can be used as the identification criterion for typical discharge fault types.
Effect characteristics of ANFs/SiO2 layer self-assembly on the insulation properties of aramid/epoxy composites
Authors: Xie Jun , Hu Chengming , Xia Guowei , Zhang Youzhi , Qiao Longyin , Xu Bobin , Shi Xiaoyu , Xie Qing 
Published: August 2024

Abstract
Aramid fiber (AF)-reinforced epoxy (EP) resin composite materials are widely used in the application of insulation rod-reinforced components, but the adhesion performance between AFs and EP resin is poor, which easily leads to interfacial defects and even gradually develops into breakdown, flashover, and other faults. In this study, a simple, environmentally friendly, diverse, and highly designable layer-by-layer self-assembly modification method was adopted to assemble aramid nanofibers/SiO2 onto the surface of AFs. The modified AFs were then used to produce composite materials with EP resin. By testing the interface breakdown, flashover, and leakage current of the AF/EP resin composite materials, the influence mechanism of AF surface modification on the material interface insulation performance was studied. The results show that the insulation performance of the modified composite material first increases and then decreases with the increase in the number of assembled layers, with the maximum increase in breakdown voltage being 93.56% and the maximum increase in flashover voltage being 30.91%.
Remarkably improved photo-charging and dark-discharging current in a faradaic junction solar rechargeable device by regulating the morphology of a semiconductor
Authors: Wan Ziyi , Jiang Dongjian , Zheng Yuzhan , Fu Ye , Sun Xiao , Wang Bo , Cui Cuixia , Yao Changping , Luo Wenjun , Zou Zhigang 
Published: August 2024

Abstract
Two-electrode solar rechargeable devices can converse and store solar energy without external bias. However, the photo-charging and dark-discharging current of these devices is low and limits their practical applications. Here, the photo-charging and dark-discharging current of Si/poly(N-methylpyrrole) (PNMPy) photoanode increases 21 and 10 times by preparing nanostructured Si semiconductor, up to 5.09 and 2.06 mA cm−2, respectively. Further studies suggest that the improved current comes from higher separation efficiency of photo-generated carriers and new electron transfer paths on the surface of nanostructured Si. Moreover, a solar rechargeable device of Si/PNMPy/H2SO4(aq)/WO3/FTO was prepared, which indicated good cyclic stability. These results deepen our understanding on the current in solar rechargeable devices and offer guidance for the design of other high-performance devices.
AlN/ScAlN composite films-based spurious free A1 mode lamb wave resonator with adjustable effective electromechanical coupling coefficient
Authors: Liu Zesheng , Liu Yan , Chen Xiang , Xie Ying , Qu Yuanhang , Gu Xiyu , Tong Xin , Li Haiyang , Liu Wenjuan , Cai Yao , Guo Shishang , Sun Chengliang 
Published: August 2024

Abstract
Narrow-band filters are widely applied in the narrow-band Internet of Things (NB-IoT). To meet the diverse bandwidth requirements of NB-IoT applications, this work presents the first antisymmetric (A1) mode Lamb wave resonators (LWRs) based on aluminum nitride (AlN) and AlN/ScAlN composite films. The impact of structural parameters, including pitch (P) and duty factor (DF), on main mode excitation and suppression of spurious modes is investigated. The optimal P and DF are found to be 10 μm and 0.05, respectively. Based on spurious-free A1 LWRs, an AlN/Sc0.096Al0.904N composite film is utilized to adjust the effective electromechanical coupling coefficient

k

eff

2

. The experiment results demonstrate a tunable

k

eff

2

from 0.40% (5 MHz) to 0.25% (3 MHz), realizing a 37.5% adjustment range of

k

eff

2

, which establishes a foundation for narrow-band tunable filters.
Impedance matching design for capacitively coupled plasmas considering coaxial cables
Authors: Yu Shimin , Chen Zili , Xu Jingwen , Wang Hongyu , Wang Lu , Wang Zhijiang , Jiang Wei , Schulze Julian , Zhang Ya 
Published: August 2024

Abstract
Capacitively coupled plasmas (CCPs) are widely used in plasma processing applications, where efficient power coupling between the radio frequency (RF) source and the plasma is crucial. In practical CCP systems, impedance matching networks (IMNs) are employed to minimize power reflection. However, the presence of coaxial cables can significantly impact plasma impedance and matching performance. We develop a comprehensive simulation framework for the IMN design of CCPs, fully considering the effects of RF coaxial cables. The model self-consistently couples a distributed transmission line (TL) model, a lumped-element circuit model, and an electrostatic particle-in-cell model. This coupled model is used to investigate the impact of coaxial cables on matching performance under various discharge conditions and cable configurations. The simulation results indicate that the optimal power transmission efficiency was achieved after 6 matching iterations. The power coupled to the CCP increased from 2.7 W before matching to 180.9 W, and the reflection coefficient ultimately decreased to 0.003. The results also reveal that neglecting the cables will lead to a decrease in the power dissipated in the CCP. The proposed method demonstrates effectiveness in achieving impedance matching for different gas pressures (75–300 mTorr) and cable lengths. It can be concluded that the matching speed is faster for an appropriate cable length. This work provides valuable insights into the role of TLs in CCP impedance matching and offers a practical tool for optimizing power delivery in realistic CCP systems with RF coaxial cables.
Dual-comb parallel sampling absolute distance measurements with an extended non-ambiguity range
Authors: Zhai Yameng , Jia Linhua , Qu Xinghua , Zhang Fumin 
Published: August 2024

Abstract
Precise absolute distance measurements are crucial in both scientific and industrial fields. Among various techniques, dual-comb ranging stands out due to its high precision and fast acquisition rate. However, the inherent periodicity of the comb pulse train leads to the limited non-ambiguity range (NAR) and periodic measurement dead zones, thereby impeding its practical applications. Here, we propose and demonstrate an arbitrary absolute distance measurement system utilizing dual repetition rate parallel linear asynchronous optical sampling. Based on the broad spectrum of optical frequency combs and wavelength division multiplexing technology, two sets of pulse trains with different wavelength ranges and repetition rates are used as signal pulses for simultaneous distance measurement. This approach straightforwardly extends the NAR to tens of kilometers by leveraging the Vernier effect. Additionally, incorporating a variable optical delay line in the reference path eliminates the measurement dead zones, thus enabling continuous measurements. Experimental results demonstrate that our proposed ranging system exhibits an Allan deviation of approximately 0.32 μm at an averaging time of 440 ms. Compared to commercial interferometers, the ranging accuracy is better than 3.8 μm for a target mirror positioned about 7 m away. Overall, the proposed system provides a compact, fast, high-precision, and dead-zone-free long-distance ranging solution with significant practical value for various precision engineering applications.
Development of a high-power testing system for piezoelectric ceramic material
Authors: Tao Chuanyang , Xiong Yuansheng , Zhong Meipeng , Wang Gonghai , Zhou Yuqing 
Published: August 2024

Abstract
Traditionally, the testing of piezoelectric material loss occurs under low-power conditions, limiting the accurate assessment of the high-power mechanical quality factor. To address this limitation, this study proposes a high-power testing method and device for evaluating the performance of piezoelectric ceramics in practical applications. This method involves determining the resonant frequency of the sample and applying that specific frequency to drive it. The laser doppler vibrometer collects the displacement signal of the sample vibration. Subsequently, the oscilloscope records the current signal, and the data is analyzed using a terminal device to assess the high-power characteristics of the sample. To simulate a high vibration speed working environment, an applied voltage induces vibration on the sample’s surface until the maximum vibration speed is reached, at which point it is short-circuited. This method is capable of analyzing the high-power characteristics of piezoelectric ceramic materials, facilitating a further assessment of the variation of their mechanical quality factor under high-power conditions as a function of vibration velocity.
Compact side-viewing interference microscope for inner surface micro-scale topography measurement
Authors: Liu Qian , Huang Xiaojin , Li Mengxia , Li Lulu 
Published: August 2024

Abstract
Inner surface micro-scale topography is a concerned aspect in precise pipe-type workpiece manufacturing. To realize nondestructive measurement of pipe-type workpieces, in this paper a compact side-viewing interference microscope (CSIM) is proposed and a prototype is developed. Based on the Michelson-type configuration, a special interference objective is designed, in which the object plane is placed at the side of the objective to realize side viewing. To avoid mechanical scanning and reduce the measuring head size, a polarization interferometric method is employed by using a pixelated polarization camera to achieve phase shifting. The response of four polarization channels is calibrated with a simple spatial carrier method, and the surface reconstruction error is reduced by half with least-squares fittings compensation. Experiments verify that the CSIM achieves high axial resolution and roughness measurement accuracy up to the sub-nanometer level. Two pipe-type workpieces made of different materials, of which the minimum diameter is 42 mm, are successfully measured with the developed CSIM.
Research on MEMS gyroscope motion signal processing method based on stochastic resonance and optimized mode decomposition
Authors: Lu Jinbo , Ran Qi , Wang Hongyan , Tan Kunyu , Pei Zhen , Chen Jinling 
Published: August 2024

Abstract
In order to process the motion signals of micro electro mechanical system (MEMS) gyroscopes more effectively, this paper proposes a method that combines tri-stable stochastic resonance (TSR) and optimal mode decomposition improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN). Firstly, we combined TSR with the crown porcupine optimization (CPO) algorithm and ICEEMDAN to improve the signal-to-noise ratio (SNR) of MEMS gyroscope motion signals. On this basis, the signals are decomposed into many intrinsic mode functions (IMFs). Secondly, the multi-scale permutation entropy (MPE) and dynamic time warping (DTW) are used to form the IMF component judgment criteria, which decompose these IMF components into noise, aliasing, and signal components. Then, Savitzky–Golay (SG) filter and wavelet packet threshold filter are used to filter the noise component and aliasing component separately, and the filtered results are superimposed with the original signal component to obtain the reconstructed signal. Finally, the proposed method is validated through simulation signals and measured motion signals from MEMS gyroscopes, and the results show its effectiveness and practicality.
NaCl aerosol filtration over filter media with intrafiber porosity: can filtrate capacity be increased by wicking into this pore volume?
Authors: Poudyal Amulya , Tatarchuk Bruce J 
Published: August 2024

Abstract
This paper investigates a novel fiber-based filter media wherein a NaCl filtrate is collected and reservoired not only onto the surfaces of the fibers and within their inter-fiber voidage but also within the internal porosity of high pore volume nanoporous fibers or vapor grown carbon nanofibers (VGCF) floc used to fabricate the media. This transport process is shown to occur through a NaCl dissolution into the water-filled nanopores of the fiber and a subsequent intra-fiber wicking phenomenon. The study further elucidates two distinct NaCl accommodation mechanisms which are uniquely available to filter media containing nanoporous intrafiber porosity: (1) wicking and capillary condensation of liquid NaCl aerosols directly into the intrafiber pores at high RH, and (2) dissolution of otherwise solid NaCl aerosols deposited onto fiber surfaces (at low RH) into the interior nanopores of the fiber because these pores (when hydrophilic) are saturated with water (even at low RH). To investigate these two mechanistic regimes, various media were fabricated possessing multiscale porosity in the form of: (i) embedded flocs of VGCFs (4.108 cm3 gm−1 pore volume), (ii) hydrophilic and high pore volume activated carbon fibers (ACFs, 0.950 cm3 gm−1) and (iii) solid graphite fibers. These media were then comparatively evaluated toward NaCl aerosol filtration at different relative humidities. Pressure drop measurements versus filtrate accumulation and SEM-EDAX VGCF demonstrated the location and transport of NaCl into the intrafiber voidage. Media containing both VGCF floc and ACF accumulated 1200% more NaCl at low RH (and a specified pressure drop) than similar media prepared from non-porous graphite fibers, with an additional 315% increase from low to high RH. A Gibbs free energy driving force model is provided to illustrate the driving forces favoring water condensation into the nanopores and solid NaCl aerosol dissolution into the water phase. Filtration efficiency and quality factor assessments for the various media are also systematically evaluated to demonstrate the observed mechanistics.
Enhanced durability of Pd/CeO2-C via metal–support interaction for oxygen reduction reaction
Authors: Mao Xinbiao , Ou Mingyu , Zhao Wenjun , Shi Meiqin , Zheng Lingxia 
Published: August 2024

Abstract
It is a challenge to improve the long-term durability of Pd-based electrocatalysts for oxygen reduction reaction (ORR) in fuel cells. Herein, Pd/CeO2-C-T (T = 800 °C, 900 °C and 1000 °C) hybrid catalysts with metal–support interaction are prepared from Ce-based metal organic framework precursor. Abundant tiny CeO2 nanoclusters are produced to form nanorod structures with uniformly distributed carbon through a calcination process. Meanwhile, both carbon and CeO2 nanoclusters have good contact with the following deposited surfactant-free Pd nanoclusters. Benefited from the large specific surface area, good conductivity and structure integrity, Pd/CeO2-C-900 exhibits the best electrocatalytic ORR performance: onset potential of 0.968 V and half-wave potential of 0.857 V, outperforming those obtained on Pd/C counterpart. In addition, the half-wave potential only shifts 7 mV after 6000 cycles of accelerated durability testing, demonstrating robust durability.
Stiffness and damping tuning through using a piezoelectric friction damper and a layered structure
Authors: Rezvani Sina , Park Simon S 
Published: August 2024

Abstract
Vibration suppression is essential for enhancing the performance of mechanical systems, as it prevents structural damage and minimizes noise. Various methods, including passive, semi-active, and active approaches, have been developed to achieve this goal. Among these, friction dampers, primarily categorized as passive, are highly efficient in adjusting system damping and influencing energy dissipation. By modulating the normal force in the friction damper based on external force intensity, performance can be further enhanced. This study employs a piezoelectric actuator to regulate the normal force and introduces an analytical method along with finite element modeling to estimate the normal force in the friction damper. A layered structure is introduced as an additional mean to tune damping and stiffness. The performance of the semi-active piezoelectric friction damper is investigated in free and forced vibrations, including flexural and axial cyclic loads. Furthermore, the advantages of employing layered structures are investigated experimentally. Overall, the piezoelectric friction damper demonstrates effective energy dissipation during macroslip events. Nevertheless, in case of microslip, increasing the actuator voltage results in reduced damping and a marginal rise in stiffness.
Trade-off relations between Bell nonlocality and local Kochen–Specker contextuality in generalized Bell scenarios
Authors: Porto Lucas E A , Ruffolo Gabriel , Rabelo Rafael , Terra Cunha Marcelo , Kurzyński Paweł 
Published: August 2024

Abstract
The relations between Bell nonlocality and Kochen–Specker contextuality have been subject of research from many different perspectives in the last decades. Recently, some interesting results on these relations have been explored in the so-called generalized Bell scenarios, that is, scenarios where Bell spatial separation (or agency independence) coexist with (at least one of the) parties’ ability to perform compatible measurements at each round of the experiment. When this party has an n-cycle compatiblity setup, it was first claimed that Bell nonlocality could not be concomitantly observed with contextuality at this party’s local experiment. However, by a more natural reading of the definition of locality, it turns out that both Bell nonlocality and local contextuality can, in fact, be jointly present. In spite of it, in this work we prove that in the simplest of those scenarios there cannot be arbitrary amounts of both of these two resources together. That is, in these cases we show that the violation of any Bell inequality limits the possible violations of any local noncontextuality inequality. We also explore this trade-off relation using quantifiers of nonlocality and contextuality, discussing how such a relation can be understood in terms of a ‘global’ notion of contextuality, and we study possible extensions of this result to other scenarios.
Jeans mass and Gamow temperature: insights from q-Deformed systems
Authors: Senay M 
Published: August 2024

Abstract
In this study, we investigate the potential for star formation within a gas system governed by q-deformed statistics. Our findings show that stars with masses below the conventional Jeans mass threshold can indeed form, with the specific formation depending on the value assigned to the deformation parameter q. In particular, the application of q-statistics allows the emergence of stars with reduced Jeans mass requirements. In addition, within the framework of q-deformed kinetic theory, the ignition temperature of a star may exhibit a decrease relative to the traditionally accepted Gamow temperature. This suggests important implications for the mechanisms driving star formation and the thermal dynamics in stellar bodies under the influence of q-deformation.
Series solution and sensitivity analysis of central disc-shaped objects in electrical impedance tomography
Authors: Gulati Shantam , Jampana Phanindra , Sastry C S 
Published: August 2024

Abstract
Electrical Impedance Tomography (EIT) is a non-intrusive imaging technique applied in various domains, such as medical imaging, process industries, and geophysics. Estimating the diameter of the air core in a Hydrocyclone is one of the applications of EIT in the process industry. Existing reconstruction algorithms only provide a diffuse reconstruction. Motivated by this, we develop fundamental sensitivity estimates for reconstructing central disc-shaped objects in EIT. We calculate the derivative of the voltages on the electrodes as a function of the radius of central disc-shaped phantoms and compare the theoretical findings with finite element method (FEM) results. We find that the sensitivity (i.e., the derivative of voltages to the radius of the conductivity disc) calculated through our analysis matches the FEM results and is higher for larger radii.
Exploring the effects of the positional configuration of a molecular complex on the electronic structure and optical response in a quantum ring
Authors: Sakiroglu S , Sari H 
Published: August 2024

Abstract
In this study, the energy spectrum, binding energy, and optical intersubband transitions of a molecular complex confined in a quantum ring defined by Gaussian-type potentials were theoretically investigated within the effective mass approximation. The energy states and corresponding wave functions were derived from the solution of the Schrödinger equation using a two-dimensional diagonalization method. The results show that the energy spectrum, binding energy, and intersubband optical transitions show significant sensitivity to the arrangement of the donor atoms and characteristic size parameters of the geometric confinement and repulsive core potential. In conclusion, the structural parameters of the quantum rings and the configuration of the donor atoms provide a new degree of freedom in the tuning of the electronic structure, the stability of Coulombic binding, and the optical response of a molecular complex confined in a quantum ring system.