bluuebunny/crossref_metadata_2025 huggingface dataset:
Empirical interatomic potential development and classical molecular dynamics simulation of monolayer group-III monochalcogenides: insights into thermal transport properties
Authors: Karaaslan Yenal
Published: September 2024

This research addresses the lack of comprehensive studies utilizing classical molecular dynamics simulations for monolayer group-III monochalcogenide materials. These materials, including GaS, GaSe, and InSe, have shown promise for diverse applications but lack well-defined empirical interatomic potentials in the literature. This study is concentrated on the development of empirical interatomic potential parameters for these materials using the particle swarm optimization method, filling a gap in the literature regarding classical molecular dynamics simulations. The parameters are optimized based on fundamental physical characteristics such as the lattice constants, bond lengths, phonon dispersions, and the equation of state, obtained from first-principles calculations. The developed potential parameters are then employed to predict lattice thermal conductivity through non-equilibrium classical molecular dynamics simulations, providing insights into the thermal transport properties of these materials.
In-situ construction of novel Sb2(S,Se)3/CdSe S-scheme heterojunction with enhanced photoelectrochemical performance
Authors: Yang Yuanhao , Ma Zhen , Wei Xueling , Sun Qian , Zhang Dekai , Liu Enzhou , Miao Hui
Published: September 2024

Antimony selenosulfide (Sb2(S,Se)3) was considered to have great potential for photoelectrochemical (PEC) water splitting applications due to its excellent chemical stability, good light absorption, abundant reserves and non-toxicity. However, Sb2(S,Se)3 faces some limitations in the field of PEC, such as the serious recombination problem of photogenerated carriers. Therefore effectively restraining its deep-level defects is the crucial for enhancing its PEC properties. In this paper, We successfully fabricated Sb2(S,Se)3/CdSe S-scheme heterojunction via one-step hydrothermal method, which improves its solar absorption capacity, facilitates efficient carrier separation. And, Sb2(S,Se)3/CdSe S-scheme heterojunction can suppress the adverse effects of deep-level defects on the PEC performance of Sb2(S,Se)3. Under simulated solar irradiation, the light current density can reach 4.02 mA cm−2 (33.5 times that of monomeric Sb2(S,Se)3) at 1.23 VRHE, accompanied by low initial voltage and extremely high surface charge injection efficiency. This study is of great significance for the application of Sb2(S,Se)3 in the PEC field.
Study of intricate extraordinary Hall effect and magnetization switching behavior in graded GdFeCo ferrimagnet
Authors: Bhatt Ramesh Chandra , Ye Lin-Xiu , Lin Jia-Hong , Hai Ngo Trong , Wu Jong-Ching , Wu Te-ho
Published: September 2024

This study delves into the unique properties of the GdFeCo Hall bar with a vertical composition gradient. Our exploration includes a detailed analysis of the temperature-dependent extraordinary Hall effect (EHE) response and magnetization-switching behavior. The findings reveal a FeCo-rich state at room temperature, characterized by an asymmetric drop at 20 Oe and a magnetic compensation temperature (T
comp) around 150 K. The presence of triple hysteresis loops at 280 K and 270 K, along with unexpected changes in the EHE resistance difference (ΔRXY
) at temperatures distant from T
comp, hint at complex compositional effects similar to the artificial skyrmion-like Hall effect. The temperature points for zero ΔRXY
values at ±30 kOe and ±4 kOe show a difference of 18 K, suggesting a spin-flop effect at compensation. Detailed analysis near T
comp uncovers multiple loops, indicating coexisting Gd and FeCo sublattices with varied compositions. The magnetization switching experiments demonstrate field-driven switching and a limited role of electrical current in the system. These unique findings enhance our understanding of compositionally controlled ferrimagnets for spintronic applications.
A brief review of microstructure design in transition metal-based magnetocaloric materials
Authors: Gong Yong , Miao Xuefei , Qian Fengjiao , Xu Feng , Caron Luana
Published: September 2024

Magnetic cooling, a solid-state refrigeration technology based on the magnetocaloric effect, has attracted significant attention in space cooling due to its high energy-efficiency and environmental friendliness. Transition metal-based magnetocaloric materials (MCMs) with the merit of low-cost have emerged as promising candidates for efficient magnetic refrigeration applications. This review explores the intricate relationship between microstructure and multiple properties (e.g. magnetocaloric properties, mechanical stability, thermal conductivity, and functional reversibility) of these materials. A variety of microstructural manipulation approaches (e.g. crystallographic texture, precipitates, micropores, atomic-scale defects, size effect, and composites) are examined for their effects on the comprehensive performance of MCMs. We show that microstructure design provides an effective tool to achieve excellent performance in multiple aspects, which may facilitate the commercialization of transition-metal based MCMs.
Bearing RUL prediction and fault diagnosis system based on parallel multi-scale MIMT lightweight model
Authors: Deng Xingchao , Zhu Guanhua , Zhang Qinghua
Published: September 2024

In contemporary industrial production, the significance of safety is increasingly evident, as the degradation and failure of machinery and equipment pose potential safety hazards. Consequently, there is a growing trend toward real-time monitoring, prediction, and diagnosis of industrial equipment to mitigate the unpredictable impacts on life and property safety caused by sudden failures. To address this issue, this paper proposes a real-time degradation anomaly detection system based on parallel multiscale autoencoders, along with a lightweight model for parallel multiscale multi-input multi-task applications in bearing Remaining Useful Life (RUL) prediction and fault diagnosis. Firstly, the multiscale autoencoder method is employed to simulate actual working conditions and reconstruct original vibration signals, thereby establishing intervals for detecting abnormal degradation. The interval [0, µ +3σ] interval is utilized to assess abnormal degradation based on reconstruction errors, with the first Prediction Time determined adaptively. Secondly, a method for constructing dimensionless auxiliary datasets is introduced, which adopts a multi-input format based on deep separable convolution for feature extraction from original vibration signals, kurtosis, and peak values. This approach enhances the prediction and diagnostic performance of the lightweight model. Finally, a multi-task output method that combines clustering and regression is implemented to achieve RUL prediction and fault diagnosis for bearings. The proposed method addresses the limitations of traditional bearing RUL prediction and diagnosis techniques, demonstrating both theoretical innovation and practical engineering applications. Validation on two bearing datasets confirms the effectiveness of the proposed method.
Salt-coated air oxidation nanodiamond surface purification with a photoluminescence spectroscopy quality control
Authors: Savinov S A , Kolomiets T Yu , Bi Dongxue , Sychev V V
Published: September 2024

Emerging fields of quantum technologies and biomedical applications demand pure nanodiamonds (NDs) with well-defined surface chemistry. Therefore, an inexpensive, scalable and eco-friendly ND surface purification technology is required. In this study, we report our method, salt-coated air oxidation (SCAO) thermal annealing, to achieve uniform purification of a ND surface without the loss of diamond material. A photoluminescence (PL) spectroscopy quality control method is proposed to evaluate the degree of purification. The presence of an isoemission point in the set of nitrogen vacancy (NV) center PL spectra, obtained through the photochromic effect, is examined as a surface purity indicator. The ratio of the NV centers in NDs after the SCAO treatment was determined by decomposing the PL spectra using the non-negative matrix factorization technique.
Dose-rate effects and tumor control probability in 177Lu-based targeted radionuclide therapy: a theoretical analysis
Authors: Galler M , Chibolela C , Thiele F , Rogasch J M M , Amthauer H
Published: September 2024

Objective.
177Lu-based targeted radionuclide therapy (TRT) has become an important cancer treatment option in recent years, in particular in the treatment of advanced prostate cancer and metastasized neuroendocrine tumors. Although it is known from conventional radiotherapy that the temporal dynamics of the dose-rate can be of relevance for tumor cell survival, the analysis of TRT efficacy usually considers only the absorbed dose. Thus, the aim of this theoretical analysis is to shed light on the possible effects of the pattern of dose-rate in TRT on tumor control probability (TCP). Approach. For this purpose, TCP is studied numerically in a typical four-cycle treatment regime based on the mechanistic lethal-potentially lethal model and the Zaider–Minerbo model for TCP including repopulation of tumor cells. Main results. It is shown that the dose-rate pattern in TRT can have a substantial effect on TCP even though the absorbed dose in the tumor lesion is unchanged. These dose-rate effects are particularly evident when repair of potentially lethal lesions is slow. Significance. The results indicate that in some situations in the analysis of the efficacy of TRT it is necessary to consider the full dose-rate pattern instead of the absorbed dose alone. This can be highly relevant for optimization and further development of TRTs. In particular, it could be of relevancy in studying the efficacy of newly emerging treatment concepts that combine the use of TRT and drugs that inhibit DNA damage repair.
Modeling the hundreds-of-nanoseconds-long irradiation of tin droplets with a 2 µm-wavelength laser for future EUV lithography
Authors: de Lange S J J , Hemminga D J , Mostafa Y , Meijer R A , Versolato O O , Sheil J
Published: September 2024

The properties of an extreme ultraviolet (EUV) source driven by hundreds-of-nanoseconds-long laser pulses of

λ

laser

=

2 µm wavelength are investigated through radiation-hydrodynamic simulations. We show that single-pulse irradiation of 30 µm-diameter tin droplets can generate in-band energies

∼

30

mJ directed in the 2π sr solid angle subtended by the collector mirror, yielding energies ∼100 mJ produced from 45 µm-diameter droplets. Time-integrated in-band EUV emission profiles, generated by taking Abel transforms of the local net in-band emissivity, reveal EUV source sizes in the axial (laser) direction × radial direction of ∼600 (1000) × 100 (150) µm2 for 30 (45) µm-diameter droplets. We find that approximately 74% of the total in-band emission is produced during the first half of the total propulsion distance irrespective of droplet size or laser intensity. Furthermore, we propose a one-dimensional analytical propulsion model to qualitatively explain the simulated droplet trajectory and to predict the time taken for the droplet to vaporize. These findings offer motivation for the development of high-power EUV sources based on single-pulse, hundreds-of-nanoseconds-long irradiation of tin droplets.
Numerical analysis on the performance enhancement in AlGaN/GaN vertical CAVET with InGaN/AlN/InGaN hybrid current blocking layer
Authors: Yi Huang , Wu Yanjun , Gao Sheng , Wang Qi , Hongsheng Zhang , Haishi Wang , Han Genquan
Published: September 2024

In this paper, we propose an enhanced superjunction AlGaN/GaN vertical current aperture vertical electron transistor (CAVET) that integrates a novel hybrid InGaN/AlN/InGaN current blocking layer (CBL) situated above the P-column, directly beneath the channel. The incorporation of InGaN substantially elevates the device’s saturation output current by introducing a subchannel beneath the AlGaN/GaN heterojunction conducting channel. Nonetheless, the introduction of AlN engenders a two-dimensional hole gas of opposite polarization direction via the GaN/AlN heterojunction, which aids in depleting the two-dimensional electron gas within the channel, thereby mitigating the issue of negative threshold voltage (V
th) bias occasioned by the subchannel introduced by InGaN. The outcomes demonstrate that the maximum saturation output current (I
d) for the proposed architecture is 361.5 mA mm−1, with a V
th of 1.63 V, marking increases of 98.6% and 0.08% over the traditional superjunction CAVET, respectively. Simultaneously, the breakdown voltage (V
br) of the designed device is recorded at 12 064 V, and the specific on-resistance (R
on,sp) is 6.45 Ω·mm, showcasing a enhancement figure of merit of 32.9% in comparison to the traditional superjunction CAVET.
Spatial coding metastructure for single-sensor impact region recognition
Authors: Jiang Tianxi , Zhou Tianyue , Wang Xihao , Li Tianqi , Jin Hu , Zhang Shiwu , Peng Zhi-Ke , He Qingbo
Published: September 2024

The rapid development of aircraft has created a strong demand for structural health monitoring, but current methods that rely on multiple sensor fusion suffer from complex hardware systems. Computational sensing with metastructures provides a promising approach to reduce sensing cost, but the lack of calibrated information makes it challenging to identify impact regions. In this study, we propose a concept of spatial coding metastructure for impact region recognition with a single sensor. Owing to the multi-order local resonance effect, the metastructures are capable of producing multiple vibration modulations over a wide frequency band. We demonstrate that the frequency-dependent vibration modulation effects of the metastructures on different test regions are distinguishable, a characteristic referred to as spatial coding. This characteristic enables impact regions to be accurately recognized with only a single sensor by using machine learning methods. Our work not only presents promising application prospects for condition monitoring of aircraft and other mechanical systems, but also inspires the development of safer and more efficient systems in various industries.
Deformation analysis for magnetic soft continuum robots based on minimum potential energy principle
Authors: Wang Zili , Weng Ding , Li Zhaoxin , Chen Lei , Ma Yuan , Wang Jiadao
Published: September 2024

In recent years, there has been rapid development in magnetic soft continuum robots (MSCRs). MSCRs are facilitated by the uniform dispersion of hard magnetic material particles within elastomers, serving as the actuating source. The external magnetic field interacts with the hard magnetic material to produce magnetic force and/or torque, leading to significant deformation over a wide range. Unlike existing pneumatic or tendon-driven robots, MSCRs do not require additional space or chambers, demonstrating potential for miniaturization. Analyzing the deformation of MSCRs and describing their nonlinear coupled magnetic-elastic deformation behavior is essential, in order to realize the further development and potential applications of MSCRs in various fields. In this study, a deformation model for MSCRs has been developed, which is based on the principle of minimum potential energy. This model accurately predicts the deflection caused by magnetic torque under an external uniform magnetic field. By comparison with experiment results, the proposed deformation analysis model presents a simple and fast modeling process in contrast to existing commercial finite element simulation software. Moreover, the proposed model exhibits good deformation prediction accuracy. By utilizing numerical method in this study to analyze the nonlinear deformation behavior of MSCRs, the constructed model can offer valuable guidance in optimizing the design and control of MSCRs. Furthermore, the deformation analysis conducted on MSCRs can elucidate the feasibility and future potential of realizing their inverse design.
A biomimetic chiral auxetic vertebral meta-shell
Authors: Sorrentino A , Genovese K , Nicolini L , Castagnetti D
Published: September 2024

The work presents a novel thin-walled biomimetic auxetic meta-shell for patient-specific vertebral orthopedic implants. The proposed design stemmed from the concept of an intrinsically multiple curved auxetic meta-structure, which is created by folding a two-dimensional bio-inspired chiral geometry according to the morphology of human vertebral cortical bones. Through a multi-view stereo digital image correlation system, we investigated the mechanical response of a bio-grade titanium (Ti6Al4V ELI) additively manufactured prototype of the meta-structure under compressive loadings. In addition, we analyzed the morphology of the prototype using a scanning electron microscopy and an optical image dimension measurement system both before and after compressive tests. An accurate Finite Element model, which exactly reproduced the geometry of the three-dimensional printed meta-shell, was implemented and calibrated against experimental results, obtaining a precise prediction tool of its mechanical response. The findings of this work demonstrate that the designed meta-shell shows a peculiar auxetic behavior, a targeted stiffness matching to that of human vertebral bone tissues and a higher global elastic strain capability compared to those of monolithic traditional vertebral body replacements.
Magnetic-field-controllable elasticity of helical spring magnets composed of magnetic-particle-polymer composites
Authors: An Hyun , Yoon Ji-Yeol , Kim Yongsub , Kim Sang-Koog
Published: September 2024

We present an experimental study demonstrating the ability to control the spring constant of helical mechanical springs using a magnetic field, achieved by embedding ferrimagnetic Fe3O4 nanoparticles within in a silicone polymer matrix. The composite material, in its gel form, was injected into a 3D-printed mold featuring a helical-spring-shaped cavity. An external magnetic field applied perpendicular to the coil axis of the spring allows the aligmment of the magnetic nanoparticle assemblies (chain axis) in the field direction. This alignment process determines the preferred magnetization orientation of the particle assembly chain, thereby balancing the magnetic force between the magnetic anisotropy field and the Zeeman field under a given external field. When the spring is subjected to compression or stretching loads under an externally applied magnetic field, these two magnetic fields modify the effective spring constant of the helical spring magnets (HSMs) by ∼31%, incresing it from 8.7 N m−1 (under no field) to 11.5 N m−1 at 300 mT. Analytical modeling using a simplified rod geometry aptly explains the experimental results, demonstrating that the spring constant linearly increases with the field strength up to 300 mT. Such composite HSMs could be utilized as active vibration absorbers or isolators due to their field-controllable elasticity.
Analytical prediction of temperature effects on Lamb wave response in smart plates and its experimental verification
Authors: Sharma B N , Kapuria S , Arockiarajan A
Published: September 2024

This article examines the effectiveness of a recently developed theoretical model for the generation and sensing of Lamb waves in thin plates with surface-bonded piezoelectric transducers in predicting temperature effects on Lamb waves and their time reversibility. In particular, the analytical model provides a closed-form solution, which incorporates both the shear-lag effect of the bonding layer and the system inertia in transducer-plate interaction modeling. Temperature-dependent material properties and thermal expansion of the system constituents are considered to predict the Lamb wave signal under a thermal environment. The accuracy of the theoretical prediction is assessed in comparison with experimental results obtained using an aluminum plate with adhesively bonded lead zirconate titanate transducers to its surface at different system temperatures ranging from 20 °C to 75 °C. Comparison is also made with experimental data and analytical solutions presented earlier without considering the inertia effect. The study reveals that the current solution accurately predicts the change in Lamb wave signal due to temperature variation, including the frequency dependency of the peak amplitude change with temperature rise. However, the theoretical model fails to predict the experimental trends when the inertia terms are neglected. The current model is also used to study the contributions of individual system parameters to the overall temperature effect on the time reversibility of Lamb waves and its dependence on the excitation frequency.
Dynamic resistance of a REBCO tape carrying direct current under a mixture magnetic field of AC field with DC-biased field
Authors: Xiao Huaqian , Ma Jun , Luo Xuezhi , Feng Bin , Li Qiao
Published: September 2024

When the REBCO coated conductor tape carries a direct current (DC) transport current whilst exposed to the alternating current (AC) magnetic field, a DC electrical resistance can be observed, which is called ‘dynamic resistance’. The high temperature superconducting (HTS) magnet wound by the REBCO tapes is located in the HTS electrical machine as field winding carrying DC transport current. The operational environment of the HTS electrical machine involves a complex magnetic field, encompassing both AC and DC components. The interaction between the AC magnetic field and the DC transport current induces dynamic resistance and dynamic loss in the REBCO tape which is a distinctive trait of REBCO tape. Additionally, the presence of an extra DC-biased magnetic field can decrease the critical current of the REBCO tape, thereby altering its electromagnetic properties and potentially compromising its safety. As the basis of superconducting magnets, it is particularly important to study the dynamic resistance and loss distribution of the single REBCO tape under a mixture of magnetic field backgrounds, according to the real working environments in various applications. In this paper, the electromagnetic model of multilayer REBCO tape based on
H
-formulation is built in COMSOL Multiphysics. The electromagnetic characteristics and dynamic resistance of the tape are presented when the tape is applied AC magnetic field and carries DC transport current. The effects of perpendicular and parallel DC-biased magnetic fields on the dynamic resistance and loss distribution of the REBCO tape are investigated in the paper. And the DC transport current safety margin will be observed in different applied DC-biased magnetic fields. This study comprehensively demonstrates the variation of dynamic resistance and loss distribution under a complex background magnetic field, which is significant for exploring the electromagnetic characteristics and calculating the loss of the HTS magnets in the HTS electrical machine.
Navigation of superparamagnetic particles with a pre-magnetized high-temperature superconducting bulk in a weak background field
Authors: Arsenault Alexandre , Sirois Frédéric , Li Ning , Soulez Gilles
Published: September 2024

Recent research has shown significant progress towards a full body magnetic drug delivery (MDD) system for use in targeted cancer treatments. Although many different MDD systems have been proposed to generate strong remote forces capable of rapidly changing directions at distances greater than 10 cm, current state-of-the-art technologies lack in force strength and/or degrees of freedom. Knowing that high temperature superconducting (HTS) bulks can achieve trapped fields an order of magnitude larger than ferromagnets, this work aims at numerically and experimentally evaluating the forces that can be produced by HTS bulks in a uniform magnetic field. We first use Hall probe measurements and finite element simulations to determine the magnetic field generated by an HTS pellet and show that both results are in good agreement. Using a combination of simulations and experiments, we then show that for a

14
×
6

 mm YBa2Cu3O

7
−
x

pellet magnetized at 2 T, remote forces on superparamagnetic microparticles are maximized at background fields of ∼50 mT. In addition, the direction of the magnetic forces can be flipped by changing the direction of the applied field relative to the HTS’s magnetization. The HTS bulk was successfully used to navigate magnetic microparticles in a glass bifurcation mimicking the hepatic artery of the human liver. Finally, we show by simulation that a large HTS pellet magnetized at 5 T in a field of ∼250 mT can generate stronger forces with more degrees of freedom than the strongest forces achievable in current MDD technologies.
Understanding vortex dynamics in CaK(Fe,Ni)4As4 and Ba(Fe,Co)2As2 single crystals under the influence of random point disorder
Authors: Haberkorn N , Xu M , Schmidt J , Suárez S , Bud’Ko S L , Canfield P C
Published: September 2024

We report on the influence of doping on vortex dynamics in 3 MeV proton-irradiated single crystals of CaK(Fe1−x
Ni
x
)4As4 (1144, x = 0.015, 0.025, and 0.03) and Ba(Fe1−x
Co
x
)2As2 (x = 0.04, 0.062, 0.066 and 0.074). Non-irradiated crystals of the 1144 system display superconducting critical temperatures ranging from 31 K for x = 0.015–20.5 K, as doping increases to 0.03. On the other hand, pristine crystals of the 122 system show Tc
values between 14.6 and 23.6 K, with the maximum Tc
occurring at intermediate doping levels. The fluence was set at 3 × 1016 p cm−2, resulting in a decrease in the Tc
by around 1.5 K for all samples and significantly affecting the vortex dynamics by reducing the flux creep relaxation compared to previously reported values for unirradiated crystals. Parameters such as vortex pinning energy U
0 and the glassy exponent μ dependencies on doping and magnetic field strength are identified. For the 1144 system, U
0 reaches values approaching 500 K for small fields in samples with Tc
= 29.3 K (x = 0.015), systematically decreasing to around 200 K as Tc
falls below 20 K. Furthermore, U
0 decreases as the field increases to 3 T for the same sample, varying from approximately 250 K to 100 K as Tc
decreases. These changes are typically accompanied by modifications in μ, gradually increasing from values around 1 towards 1.5, corresponding to small bundle relaxation in the collective creep theory. Despite differences in the substitutional disorder and magnetic phase diagram with respect to the 1144 system, the results for 122 single crystals follow a similar tendency in which U
0 usually reduces and μ increase rise as the applied magnetic field is increased. Due to moderate U
0 in these systems (few hundreds of kelvins), the resulting decay of persistent current at liquid helium temperatures is primarily determined by a balance between U
0 and bundle size contribution. These findings provide valuable insights for potential applications of these systems, particularly in the context of intrinsic superconducting parameters and the resulting pinning landscape.
Efficient solutions to time-fractional telegraph equations with Chebyshev neural networks
Authors: Ali Amina Hassan , Senu Norazak , Ahmadian Ali
Published: September 2024

This study aims to employ artificial neural networks (ANNs) as a novel method for solving time fractional telegraph equations (TFTEs), which are typically addressed using the Caputo fractional derivative in scientific investigations. By integrating Chebyshev polynomials as a substitute for the traditional hidden layer, computational performance is enhanced, and the range of input patterns is broadened. A feed-forward neural network (NN) model, optimized using the adaptive moment estimation (Adam) technique, is utilized to refine network parameters and minimize errors. Additionally, the Taylor series is applied to the activation function, which removes any limitation on taking fractional derivatives during the minimization process. Several benchmark problems are selected to evaluate the proposed method, and their numerical solutions are obtained. The results demonstrate the method’s effectiveness and accuracy, as evidenced by the close agreement between the numerical solutions and analytical solutions.
Ground penetrating radar clutter suppression based on the weighted tensor Schatten p-paradigm minimization of tensor principal components
Authors: Zhou Hao , Li Minchao , Yang Yanbo , Du Yongxing , Pan Bingbing
Published: September 2024

The issue of clutter suppression in ground-penetrating radar (GPR) detection has consistently been a prominent area of research. The existing tensor robust principal component analysis (TRPCA) approach encounters a challenge when handling different singular values, whereby all singular values are reduced to the same degree, leading to loss of information in the low-rank part. To address the aforementioned issues, this study developed a TRPCA method based on weighted tensor Schatten p-paradigm minimisation (p-TRPCA). This approach assigns distinct weights to each singular value by using a weighted tensor Schatten p-paradigm, facilitating the optimal decomposition of GPR data into low-rank clutter and sparse target components. The processing of target echoes is then completed by applying a threshold judgement to the results. The efficacy of the proposed method was validated through simulations and real-world testing. Its performance was benchmarked against established advanced clutter removal techniques in terms of peak signal-to-noise ratio (PSNR) and signal-to-clutter ratio. The findings demonstrated that the method effectively delineated the low-rank clutter matrix and sparse target matrix within the B-scan image and exhibited superior SNR compared to other methods.
Rogue-wave structures for a generalized (3+1)-dimensional nonlinear wave equation in liquid with gas bubbles
Authors: Mohan Brij , Kumar Sachin
Published: September 2024

This study explores the behavior of higher-order rogue waves within a (3+1)-dimensional generalized nonlinear wave equation in liquid-containing gas bubbles. It creates the investigated equation’s Hirota D-operator bilinear form. We employ a generalized formula with real parameters to obtain the rogue waves up to the third order using the direct symbolic technique. The analysis reveals that the second and third-order rogue solutions produce two and three-waves, respectively. To gain deeper insights, we use the Cole-Hopf transformation on the transformed variables ξ and η to produce a bilinear equation. Using the system software Mathematica, the dynamic analysis presents the graphics for the obtained solutions in transformed ξ, η, and original spatial-temporal coordinates x, y, z, t. These visualizations reveal rogue waves’ intricate structure and evolution, capturing their localized interactions and significant presence within nonlinear systems. We demonstrate that rogue waves, characterized by their substantial height and sudden appearance, are prevalent in various nonlinear events. The equation examined in this study offers valuable insights into the evolution of longer waves with smaller amplitudes, which is particularly relevant in fields such as fluid dynamics, dispersive media, and plasmas. The implications of this research extend across multiple scientific domains, including fiber optics, oceanography, dusty plasma, and nonlinear systems, where understanding the behavior of rogue waves is crucial for both theoretical and practical applications.
A comprehensive analysis of cosmic evolution in

f
(
Q
,
T
)

theory
Authors: Sharif M , Gul M Zeeshan , Shabbir Shamraiza
Published: September 2024

This paper examines the bouncing cosmology in

f
(
Q
,
T
)

theory, where

Q

represents non-metricity and

T

denotes the trace of energy-momentum tensor. The aim of this research is to study the phenomenon of a cosmic bounce, where contraction, bounce point and expansion occur at t < 0, t = 0 and t > 0, respectively. In this perspective, we consider Bianchi Type-I spacetime with perfect matter configuration to study the mysterious universe. Further, we analyze the behavior of cosmological parameters such as scale factor, Hubble parameter, deceleration parameter and equation of state parameter using three distinct functional forms of

f
(
Q
,
T
)

theory. A comprehensive examination of energy conditions is analyzed to study the matter bounce in this modified framework. Our findings indicate that the acceleration takes place in the vicinity of the bouncing point and ensures the presence of a nonsingular bounce in this theory.
A virtual anti-scatter grid for multi-energy photon counting detector systems
Authors: Purisha Zenith , Winkler Alexander , Emzir Muhammad , Hostettler Roland , Luukka Panja , Särkkä Simo
Published: September 2024

Photon-counting (PC) systems are the next technological generation of medical computed tomography (CT) imaging and is being worked on by all major system providers. CT devices that are based on PC detectors enable multi-energy data collection. The information-content of this data can be used to obtain more detailed patient data, which improves the quality of reconstructions, compared to conventional detector systems. However, PC CT systems are subject to radiation scatter as just as any other imaging systems is. Conventionally anti-scatter grids (ASG) are used to reduce the scatter effect. These are however an imperfect solution, especially for PC detectors. In this work, a software-based scatter correction method, thus a virtual ASG is proposed. The method is tailoring a new statistical model in the measurement space and combining it with the statistical inversion method called Markov chain Monte Carlo (MCMC). The method can recover the measurement data from dense projections. We present the method on simulated data of a single photon emission computed tomography (SPECT) problem for which only under-sampled data is available. However, our approach can in principle be generalised to CT, PC-CT, Positron emission tomography (PET), radiotherapy, or even digital radiography problems. The results show that the proposed model performs similarly as physical ASGs and for cases where ASGs are not possible. The model further offers a significant improvement in the quality of the reconstruction image compared to the image reconstruction from original under-sampled data.
Remote implementation of hidden or partially unknown quantum operators using optimal resources: a generalized view
Authors: Kumar Satish , Gangwar Kuldeep , Pathak Anirban
Published: September 2024

Two protocols are proposed for two closely linked but different variants of remote implementation of quantum operators of specific forms The first protocol is designed for the remote implementation of the single qubit hidden quantum operator, whereas the second one is designed for the remote implementation of the partially unknown single qubit quantum operator. In both cases two-qubit maximally entangled state, which is entangled in the spatial degree of freedom is used. The quantum resources used here are optimal and easy to realize and maintain in comparison to the multi-partite or multi-mode entangled states used in earlier works. The impact of photon loss due to interaction with the environment is analyzed for both the schemes. The proposed protocols are also generalized to their controlled, bidirectional, cyclic, controlled cyclic, and controlled bidirectional versions and it is shown that either Bell state alone or products of Bell states will be sufficient to perform these tasks with some additional classical communications in the controlled cases only. This is in sharp contrast to the earlier proposals that require large entangled states. In addition, it’s noted that remote implementation of hidden or partially unknown operators involving multiple controllers and/or multiple players who jointly apply the desired operator(s) would require quantum channels more complex than the Bell states and their products. Explicit forms of such quantum channels are also provided.
Janus monolayers Fe2SSeX2 (X = Ga, In, and Tl): Robust nontrivial topology with high Chern number
Authors: Jia 贾 Kang 康 , Dong 董 Xiao-Jing 晓晶 , Wang 王 Pei-Ji 培吉 , Zhang 张 Chang-Wen 昌文
Published: September 2024

High-performance quantum anomalous Hall (QAH) systems are crucial materials for exploring emerging quantum physics and magnetic topological phenomena. Inspired by layered FeSe materials with excellent superconducting properties, the Janus monolayers Fe2SSeX
2 (X = Ga, In and Tl) are built by the decoration of Ga, In and Tl atoms in monolayer Fe2SSe. In first-principles calculations, Fe2SSeX
2 have stable structures and prefer ferromagnetic (FM) ordering, and can be considered as Weyl semimetals without spin–orbit coupling. For out-of-plane (OOP) magnetic anisotropy, large nontrivial gaps are opened and the Fe2SSeX
2 are predicted to be large-gap QAH insulators with a high Chern number C = 2, proved by two chiral edge states and Berry curvature. When the magnetization is flipped, the two chiral edge states can be simultaneously changed and C = −2 can be obtained, revealing the fascinating behavior of chiral spin–edge state locking. It is found that the QAH properties of Fe2SSeX
2 are robust against strain. In particular, nontrivial topological quantum states can spontaneously appear for Fe2SSeGa2 and Fe2SSeIn2 because the orientations of the easy magnetic axis are adjusted from in-plane to OOP by the biaxial strain. Our studies provide excellent candidate systems to realize QAH properties with a high Chern number, and suggest more experimental explorations combining superconductivity and topology.
Automatic architecture design for distributed quantum computing
Authors: Luo 骆 Ting-Yu 挺宇 , Zheng 郑 Yu-Zhen 宇真 , Fu 付 Xiang 祥 , Deng 邓 Yu-Xin 玉欣
Published: September 2024

In distributed quantum computing (DQC), quantum hardware design mainly focuses on providing as many as possible high-quality inter-chip connections. Meanwhile, quantum software tries its best to reduce the required number of remote quantum gates between chips. However, this “hardware first, software follows” methodology may not fully exploit the potential of DQC. Inspired by classical software–hardware co-design, this paper explores the design space of application-specific DQC architectures. More specifically, we propose AutoArch, an automated quantum chip network (QCN) structure design tool. With qubits grouping followed by a customized QCN design, AutoArch can generate a near-optimal DQC architecture suitable for target quantum algorithms. Experimental results show that the DQC architecture generated by AutoArch can outperform other general QCN architectures when executing target quantum algorithms.
EEG electrodes and where to find them: automated localization from 3D scans
Authors: Tveter Mats , Tveitstøl Thomas , Nygaard Tønnes , Pérez T Ana S , Kulashekhar Shrikanth , Bruña Ricardo , Hammer Hugo L , Hatlestad-Hall Christoffer , Hebold Haraldsen Ira R J
Published: September 2024

Objective. The accurate localization of electroencephalography (EEG) electrode positions is crucial for accurate source localization. Recent advancements have proposed alternatives to labor-intensive, manual methods for spatial localization of the electrodes, employing technologies such as 3D scanning and laser scanning. These novel approaches often integrate magnetic resonance imaging (MRI) as part of the pipeline in localizing the electrodes. The limited global availability of MRI data restricts its use as a standard modality in several clinical scenarios. This limitation restricts the use of these advanced methods. Approach. In this paper, we present a novel, versatile approach that utilizes 3D scans to localize EEG electrode positions with high accuracy. Importantly, while our method can be integrated with MRI data if available, it is specifically designed to be highly effective even in the absence of MRI, thus expanding the potential for advanced EEG analysis in various resource-limited settings. Our solution implements a two-tiered approach involving landmark/fiducials localization and electrode localization, creating an end-to-end framework. Main results. The efficacy and robustness of our approach have been validated on an extensive dataset containing over 400 3D scans from 278 subjects. The framework identifies pre-auricular points and achieves correct electrode positioning accuracy in the range of 85.7% to 91.0%. Additionally, our framework includes a validation tool that permits manual adjustments and visual validation if required. Significance. This study represents, to the best of the authors’ knowledge, the first validation of such a method on a substantial dataset, thus ensuring the robustness and generalizability of our innovative approach. Our findings focus on developing a solution that facilitates source localization, without the need for MRI, contributing to the critical discussion on balancing cost effectiveness with methodological accuracy to promote wider adoption in both research and clinical settings.
Self-consistent modelling of radio frequency sheath in 3D with realistic ICRF antennas
Authors: Lu L.F. , Colas L. , Cao L. , Urbanczyk G. , Lu B. , Shen Y.Q. , Zhang X.J.
Published: September 2024

Ion cyclotron resonant frequency (ICRF) induced impurity production has raised many concerns since ITER proposed to change the first wall material from beryllium to tungsten. Enhanced DC plasma potential (V
DC) due to radio frequency (RF) sheath rectification is well known as one of the most important mechanisms behind the RF induced impurities. Our previous work (Lu et al 2018 Plasma Phys. Control. Fusion
60 035003) considered the impact of both the slow wave and the fast wave on the RF sheath rectification in a 2D geometry. It can barely recover the double-hump structure of the V
DC poloidal distribution observed in various machines when only the slow wave is modelled using the multi-2D approach which intrinsically assumes the poloidal wavenumber kz
is zero. The fast wave on the other hand is found to be more sensitive to a finite kz
and may need to be tackled in 3D. This work reports our recent progress on the 3D RF sheath modelling. In this new code, the latest RF sheath boundary conditions (Myra 2021 J. Plasma Phys. 87 905870504) and the realistic 3D ICRF antennas are implemented. Compared to the 2D results, the 3D code could well recover the double-hump poloidal distribution of V
DC even with the fast wave included, which confirms our speculation on the necessity of treating the fast wave in 3D. While the double-hump pattern is robust in the simulation, the amplitude of V
DC is found to be affected by the magnetic tilt angle and the antenna geometry. This emphasizes the importance of adopting a realistic antenna geometry in the RF sheath modelling. The double-hump V
DC poloidal structure breaks as the magnetic tilt angle increases. This is explained by the gyrotropic property of the cold plasma dielectric tensor. The spatial proximity effect we identified in the previous 2D simulations is still valid in 3D. Finally, simulation shows the slow wave dominates the RF sheath excitation in the private scrape-off layer (SOL), while the fast wave gradually takes over when moving to the far SOL region. This code could be a new tool to provide numerical support for ITER impurity assessment and ICRF antenna design.
Transport and losses of energetic particles in tokamaks in the presence of Alfvén activity using the new full orbit TAPaS code coupled to FAR3d
Authors: Betar H. , Zarzoso D. , Varela J. , Del-Castillo-Negrete D. , Garcia L. , Du X.
Published: September 2024

Recent developments and tools integrated into the TAPaS code are presented, enabling realistic scenario simulations of particle dynamics within experimental tokamak magnetic equilibria. In particular, the enhanced capabilities of TAPaS enable seamless coupling with external simulations, provided the metric and equilibrium magnetic field of the external code are known. Coupling TAPaS with the gyro-fluid code FAR3d, the transport and losses of energetic particles in the presence Alfvén eigenmodes (AEs) in DIII-D plasma discharge

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were investigated. Detailed analyses of prompt losses with and without collisions were performed. Then, further analysis was performed in the presence of electromagnetic perturbations resulting from AEs activity. The results indicate that, for the energies and the initial conditions considered here, the presence of AEs enhances the particle losses.
Early engagement will be necessary for atmospheric methane removal field trials
Authors: Scott-Buechler Celina , Jinnah Sikina
Published: September 2024

Atmospheric methane removal (AMR) refers to a suite of emerging technologies and practices that destroy atmospheric methane. There is growing interest in AMR field trials to better understand the risks and benefits of various approaches. Building on rights-based rationales from international law and core principles of environmental justice, we argue that AMR field trials should not proceed before meaningful public engagement occurs. We also draw preliminary lessons from ocean fertilization and solar radiation management cases to highlight the significance of involving members of the public in conversation about climate intervention technologies in early stages of the research and development process. While we emphasize that engagement is not a checkbox for gaining social license, these cases illustrate how neglecting public engagement can be unnecessarily detrimental to proposed research. We further point to an enhanced weathering experiment to highlight how early engagement can foster ethical processes and outcomes, which enhance alignment of research with societal values. While empirical evidence does not yet support the argument that engagement always results in the outcomes researchers desire, it does always result in justice enhancing outcomes and should therefore be pursued regardless. We advocate for diverse engagement approaches based on the nature of the technology, with a focus on collaboration with impacted communities, the public, and international interdisciplinary researchers. To ensure responsible research practices, the article calls for the development of comprehensive governance frameworks and ethical guidelines for field trials.