bluuebunny/crossref_metadata_2025 huggingface dataset:
Charge-to-spin conversion at argon ion milled SrTiO3/NiFe hetero-interfaces
Authors: Kumar Amrendra , Shashank Utkarsh , Maharana Suman Kumar , Mohan John Rex , Vas Joseph Vimal , Gupta Surbhi , Asada Hironori , Dunin-Borkowski Rafal E. , Fukuma Yasuhiro , Medwal Rohit
Published: January 2025

Two-dimensional electron gases (2DEGs) at perovskite oxide interfaces, such as strontium titanate (STO), have garnered significant attention due to their induced ferromagnetic (FM), spin–orbit coupling, and superconducting properties. The 2DEG, formed at the interface between STO and either insulating oxides or reactive metals, exhibits efficient charge-to-spin interconversion in STO/NM(non-magnetic)/FM structures. The insulating oxide layer at the STO interface attenuates the spin currents injected into the ferromagnet. In contrast, the metallic layers facilitate efficient spin current injection but suffer from spin current diffusion. Here, we present an approach to overcome these challenges by directly creating a 2DEG at the STO surface through Ar+ ion bombardment. This method enables efficient spin-to-charge conversion without an intermediate NM layer. Our experimental and simulation results demonstrate the generation of unconventional spin currents at the STO(Ar+)/NiFe (Permalloy) interface. Our findings may enable applications of complex oxide and ferromagnet interfaces for efficient charge-to-spin conversion, paving the way for low-power, room-temperature oxide-based spintronic devices.
Alchemical harmonic approximation based potential for iso-electronic diatomics: Foundational baseline for Δ-machine learning
Authors: Krug Simon León , Khan Danish , von Lilienfeld O. Anatole
Published: January 2025

We introduce the alchemical harmonic approximation (AHA) of the absolute electronic energy for charge-neutral iso-electronic diatomics at fixed interatomic distance d0. To account for variations in distance, we combine AHA with this ansatz for the electronic binding potential, E(d)=(Eu−Es)Ec−EsEu−Esd/d0+Es, where Eu, Ec, Es correspond to the energies of the united atom, calibration at d0, and the sum of infinitely separated atoms, respectively. Our model covers the two-dimensional electronic potential energy surface spanned by distances of 0.7–2.5 Å and differences in nuclear charge from which only one single point (with elements of nuclear charge Z1, Z2, and distance d0) is drawn to calibrate Ec. Using reference data from pbe0/cc-pVDZ, we present numerical evidence for the electronic ground-state of all neutral diatomics with 8, 10, 12, and 14 electrons. We assess the validity of our model by comparison to legacy interatomic potentials (harmonic oscillator, Lennard-Jones, and Morse) within the most relevant range of binding (0.7–2.5 Å) and find comparable accuracy if restricted to single diatomics and significantly better predictive power when extrapolating to the entire iso-electronic series. We also investigated Δ-learning of the electronic absolute energy using our model as a baseline. This baseline model results in a systematic improvement, effectively reducing training data needed for reaching chemical accuracy by up to an order of magnitude from ∼1000 to ∼100. By contrast, using AHA+Morse as a baseline hardly leads to any improvement and sometimes even deteriorates the predictive power. Inferring the energy of unseen CO converges to a prediction error of ∼0.1 Ha in direct learning and ∼0.04 Ha with our baseline.
An improved coarse alignment algorithm for SINS based on rotation modulation
Authors: Yang Yong , Li Donglin , Kong Lingbing , Xu Kaijun , Xiang Honghui
Published: January 2025

Coarse alignment in strapdown inertial navigation systems (SINSs) is a critical step in ensuring initial alignment and the proper functioning of the system. The primary challenge in this process lies in reducing the alignment time while enhancing accuracy, particularly as conventional analytic algorithms often suffer from decreased precision due to measurement errors in accelerometers and gyroscopes. This paper proposes an improved coarse alignment algorithm by introducing single-axis continuous rotation modulation to compensate for the errors in gyroscopes and accelerometers, thus improving accuracy. The simulation results show that within the same alignment time, this method enhances horizontal accuracy by ∼80% compared to traditional analytic coarse alignment algorithms. The proposed approach effectively mitigates the constant bias errors of inertial sensors, significantly improving the overall alignment precision of the SINS.
Evaluation and prediction of coal seam mining mode: Coefficient of Variation-TOPSIS and CNN-NGO methods
Authors: Li Haixiong , Wang Fei
Published: January 2025

Selecting the appropriate method for coal seam mining is the foremost task for the safe and efficient production of coal mines. This study explores and validates an integrated evaluation system that enhances the accuracy of predicting coal seam mining mode by comparing traditional evaluation methods with machine-learning techniques. The weights of the evaluation indicators for coal seam mining were allocated using the coefficient of variation method, followed by a comprehensive evaluation using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). In addition, a Convolutional Neural Network (CNN) regression model was constructed and optimized with the Northern Goshawk Optimization (NGO) algorithm, resulting in a more precise CNN-NGO prediction model. A detailed comparative analysis of these two models was conducted. The results indicate that the level of equipment is a key factor affecting the method of coal seam mining, holding the highest weight among all evaluation indicators. The CNN-NGO model demonstrates excellent performance in predicting coal seam mining mode, with its predictions highly consistent with actual mining practices. Specifically, in the practical application case of the WJZ 15206 working face, the model successfully predicted the high mining height as the most likely mining method, with a prediction index of 2.4265, close to the normalized output value of 2 for large mining height. This study not only provides scientific methods and tools for the evaluation and prediction of coal seam mining mode but also contributes to the intelligent development of the coal mining industry.
Investigation of combination-mode air plasma and its effect on infected wounds
Authors: Shu Jiangling , Li Zhuo , Zhang Zizhu , Zhao Xinyi , Zhang Jingshuo , Qi Miao , Ni Tianji , Ge Ruirui , Liu Dingxin , Xu Dehui
Published: January 2025

Cold atmospheric plasma is considered to be an effective wound-treatment technique because of its efficient bactericidal properties and gentleness to the human body. The purpose of this study was to explore a new way of generating plasma that produces large amounts of N2O5, which exhibits superior biological effects compared to O3. This method is referred to as “combination mode” because it combines both dielectric barrier discharge and gliding arc discharge. A plasma-generating device was designed according to the principles of this combination mode. This outputs plasma-activated air (PAA) for both convenience and effectiveness. We sought to verify the effectiveness of PAA in the treatment of naturally infected wounds. The results of in vivo experiments showed that all groups treated with PAA had better wound-healing profiles than the control group, and the group treated with combination-mode plasma for 3 min had the best performance. The results of 16S rDNA analysis demonstrated that PAA is a good inhibitor of the most common infection-causing bacteria. Immunohistochemistry analysis revealed an increase in the secretion of growth factors and a decrease in both inflammatory and anti-inflammatory factors in the wound tissue of the treated groups. Finally, preliminary indications of the biosafety of PAA were provided by considering the body-weight trends in the animals and examining tissue sections from their five major organs. This study confirms the positive effect of combination-mode plasma on the healing of infected wounds and explores its mechanisms from multiple dimensions, contributing to the further application of PAA in clinical treatment.
Deuterium and tritium anomalous transport in the generalized Hasegawa–Wakatani resistive drift wave turbulence model with finite ion Larmor radius
Authors: Smirnov R. D. , Krasheninnikov S. I.
Published: January 2025

Anomalous transport of mixed deuterium–tritium plasma in the edge of magnetic fusion reactors is investigated using numerical solutions of resistive drift wave turbulence model equations, including finite Larmor radius effects, that are derived within the generalized Hasegawa–Wakatani framework. The anomalous cross field diffusivities of deuterium and tritium are compared in turbulence regimes with different values of the electron adiabaticity parameter controlling the existence of zonal flow. The dependence of the tritium-to-deuterium diffusivity ratio on the deuterium and tritium densities and the logarithmic density gradients is analyzed, and a scaling relation is obtained.
Global modeling of iodine Hall thruster performance and discharge properties
Authors: Bianchi Francesco M. , Vinci Alfio E. , Garrigues Laurent
Published: January 2025

A 0D model for an iodine-fed Hall thruster is presented. A complete set of reactions is used to account for iodine plasma chemistry phenomena and trace the presence of multiple neutrals and ionized species. The model is developed using novel assumptions based on experimental data trends as derived from the literature. The simulation domain is divided into two zones in order to refine the iodine molecule dissociation process localized in the low electron temperature region found upstream in the channel. After validating a xenon version of the model against SPT-100 characteristics, numerical results are compared against experimental data relative to a low-power iodine-fed Hall thruster. Discharge current and thrust are predicted with satisfactory quantitative agreement, and overall trends are effectively captured. The numerical results indicate a relatively large portion of ionized molecules, while negative ions appear to occur in non-negligible amount upstream in the thruster channel.
Polaron hopping induced dual-band absorption in all amorphous cathodic electrochromic oxides
Authors: Zhang Renfu , Yin Menghan , Shao Peipei , Huang Qingjiao , Niklasson Gunnar A. , Wen Rui-Tao
Published: January 2025

Electrochromic oxides have tremendous potential applications in smart windows, displays, and camouflage due to their capability for selective modulation of visible and near-infrared optical spectra. Although these applications are dependent on the optical performance, the origin of the optical absorption in electrochromic oxides is not clear. Here, we demonstrate that the electrochromism of all amorphous cathodic electrochromic oxides can be described by a combination of polaron and bipolaron hopping. Based on the valences of the metallic constituents, we model experimental optical absorption spectra by polaron theory and assign two prominent absorption peaks to polaronic and bipolaronic charge transfer excitations. However, in the special case of V2O5, three peaks were necessary to fit the optical spectra. The activation energies of polaronic and bipolaronic hopping were remarkably similar for all the cathodic oxides studied. Within the framework of polaron absorption, V2O5 would be categorized as a cathodic oxide, rather than as a mixed anodic/cathodic material as in the conventional picture. We emphasize that our findings here not only offer a profound understanding of all amorphous cathodic electrochromic oxides but also pave the way for exploring electrochromic oxides with dual-band modulations.
Origin of the formation of isostructural bcc-Fe+bcc-Cu nanocomposites in Fe–Cu alloy via vacuum co-deposition
Authors: Ustinov A. I. , Olikhovska L. O. , Demchenkov S. O. , Skorodzievskii V. S. , Polishchuk S. S. , Melnychenko T. V.
Published: January 2025

This study examined the influence of substrate temperature and the ratio of iron and copper vapor flow on the structural state of Fe–Cu vacuum condensates. XRD patterns of the condensates deposited under specific electron beam physical vapor deposition process parameters revealed peaks corresponding to either bcc or bcc+fcc phases. Analysis of the lattice parameter of the single bcc structure indicates that only a portion of the copper atoms dissolve in the bcc-Fe lattice, while undissolved copper atoms form bcc-Cu inclusions that are coherent with the bcc-Fe lattice. A model for the formation of the bcc-Cu structure as an adaptive phase is proposed. The formation of the adaptive phase in vacuum condensates is driven by the bcc-Cu epitaxy on the surface of bcc-Fe crystallites and excess vacancies in the condensate structure. As the copper concentration in the isostructural Fe–Cu composite increases, the level of microstrain in its bcc crystal lattice also increases. The transformation of bcc-Cu particles into fcc-Cu via a shear mechanism occurs when heated above 400 °C. It was found that increasing the deposition temperature reduces the concentration range for the formation of the isostructural composite. It is suggested that higher deposition temperatures and increased copper concentration lead to larger copper particle sizes and reduced excess vacancy concentration, which disrupts their coherence with the bcc-Fe matrix. As a result, a composite with a eutectic-like microstructure consisting of bcc-Fe and fcc-Cu phases forms directly during vapor phase condensation.
Interstitial nitrogen-modified (Y1−xSmx)2Fe14BNy compounds toward enhanced operating frequency and reduced power loss
Authors: Meng Chao , Zhang Zenan , Liu Zhaochen , Jin Xiaowei , Jia Zhenlin , Feng Hao , Xue Desheng
Published: January 2025

Soft magnetic materials with high operating frequency and low power loss are crucial for electricity transmission and utilization. However, finding an effective method to improve the operating frequency while minimizing power loss in these materials remains a significant challenge. Herein, we synthesized the (Y1−xSmx)2Fe14B (0≤x≤1) compounds and introduced nitrogen atoms into their interstitial crystal sites via the gas–solid reaction, remarkably improving their operating frequency and reducing power loss. For the compounds with x = 0.15, the operating frequency increased from 1.7 to 5.5 MHz, with the imaginary part of relative permeability decreased from 6.1 to 1.6. The power loss decreased from 1607.7 to 664.1kW/m3, and loss separation indicated that eddy current loss Peddy was significantly suppressed by nitriding from 1397.7 to 547.9kW/m3. The conductivity decreased by approximately 43% by nitriding, from 9380.9 to 5359.0 S/m. These results demonstrate that tuning power loss through nitrogenation of rare-earth transition metal intermetallic compounds is an effective method for developing new high-frequency and low power loss soft magnetic materials.
Mixed atomistic–implicit quantum/classical approach to molecular nanoplasmonics
Authors: Illobre Pablo Grobas , Lafiosca Piero , Bonatti Luca , Giovannini Tommaso , Cappelli Chiara
Published: January 2025

A multiscale quantum mechanical (QM)/classical approach is presented that is able to model the optical properties of complex nanostructures composed of a molecular system adsorbed on metal nanoparticles. The latter is described by a combined atomistic–continuum model, where the core is described using the implicit boundary element method (BEM) and the surface retains a fully atomistic picture and is treated employing the frequency-dependent fluctuating charge and fluctuating dipole (ωFQFμ) approach. The integrated QM/ωFQFμ-BEM model is numerically compared with state-of-the-art fully atomistic approaches, and the quality of the continuum/core partition is evaluated. The method is then extended to compute surface-enhanced Raman scattering within a time-dependent density functional theory framework.
Design of resonant cavity-enhanced InAs/GaSb superlattice LWIR photodetector
Authors: Gong Ruixin , Zhu Lianqing , Lu Lidan , Feng Qingsong , Chen Yang , Liu Bingfeng , Chen Yuhao , Zhang Yuanbo , Zhang Shiya , Liu Zhiying
Published: January 2025

Type-II superlattices have recently emerged as a focal point in long-wavelength infrared (LWIR) detection, showcasing remarkable potential across various applications. In this work, we have conducted a theoretical investigation into the band structure and optical properties of 14/7 monolayers (ML) InAs/GaSb superlattices (SLs), employing density functional theory. Our findings indicate that the energy gap of these SLs is determined to be 0.111 eV through energy band structure analysis using the Heyd–Scuseria–Ernzerhof method. Moreover, we have designed a resonant cavity-enhanced “Φ” structure for the 14/7 ML InAs/GaSb SLs infrared detector. This innovative design markedly enhances absorption efficiency, increasing it from 16.48% to an impressive 76.35% at the 11.2 μm wavelength. Further analysis includes a detailed examination of the electric field distribution within this structure and a comprehensive examination of the enhanced plasmonic resonator’s perfect absorption phenomenon. The results from these analyses underscore the exceptional absorption capabilities of our resonant cavity-enhanced infrared detector, indicating its potential for significant applications in LWIR SLs focal plane.
Effects of shear stability and residual stresses in computer glasses
Authors: Lerner Edan
Published: January 2025

Numerical investigations of disordered solids often involve employing a fixed simulation-box geometry and periodic boundary conditions, the latter are intended to minimize surface effects. One consequence of this methodological approach is that the resulting solids typically feature residual macroscopic stresses and could feature negative shear moduli, in which case they are deemed unstable to shear. In this work, we review and validate via numerical simulations the statistical theory that explains how the fraction of shear-unstable solids within an ensemble of solids created via the same protocol depends on the system size. We further demonstrate and rationalize how the fraction of disordered soft-sphere packings that are unstable to shear depends on their proximity to the unjamming point at which solidity is lost. Finally, we show that residual-stress-free structural glasses created in a fixed-box geometry have the same vibrational and elastic properties as glasses that do feature residual stresses. This result seemingly contradicts previous work that shows that residual-stress-free samples created using variable box shape feature different vibrational properties. These observations raise questions about the equivalence of constant-stress vs constant box-geometry ensembles in the thermodynamic limit, which are discussed together with future research directions.
Detect material volume by fusing heterogeneous camera target detection and depth estimation information
Authors: Tian Wei , Cheng Xuecong , Zhang Yipeng , Lin Huazhi
Published: January 2025

Material piles, such as coal piles, sand piles, and gravel piles, are ubiquitous in real life, but in actual production, it is not easy to measure the remaining volume. The visual measurement algorithm is the mainstream solution for the volume measurement. Monocular measurement is fast, but there are problems of low accuracy and instability; binocular measurement is better, but it is not easy to extract the volume of the measured object; multi-eye measurement is accurate but slow. To combine the advantages of monocular and binocular measurements, this paper proposes an algorithm that integrates heterogeneous camera depth estimation and target detection information to realize material volume detection. First, the improved DeepLabV3+ is used to detect the edge of the material pile in the monocular camera target detection, and the CREStereo cascade network is used in the binocular camera to calculate the depth map; then, SIFT is combined with FLANN to map the edge of the material pile into the depth map and separate the depth of the material pile; finally, the three-dimensional coordinates of each point in the material pile are calculated, and the volume is calculated using the microelement method. Experiments show that the average accuracy of this method is 92.9%.
Numerical research on the rotor “super blade/vortex interaction noise” generation mechanism in helicopter roll maneuver state
Authors: Wang Weiqi , Chen Xi , Yang Tao , Zhao Guoqing , Zhao Qijun
Published: January 2025

To explore the evolution law of rotor vortex and aeroacoustic characteristics during helicopter roll maneuver flight, numerical simulations were conducted in different roll rates based on the high-precision computational fluid dynamics method and the Ffowcs Williams-Hawkings equation. Initially, we verified the collective pitch increased test and the blade/vortex interaction (BVI) test cases. The comparison results show that the constructed method can capture the aerodynamic characteristics of rotor transient maneuvering states and has reliable predictive capability for BVI noise. Then, the aeroacoustic characteristics analyses of different right roll rates was performed. It was found that in the right roll state, multiple vortices merge and develop into a higher-intensity “supervortex system” near the 75° azimuth angle, triggering “superblade/vortex interaction noise” (Super-BVI) upon collision with the subsequent blade, with a maximum increase in the overall sound pressure level (OASPL) of approximately 16 dB. Next, numerical simulations were carried out for different left roll rates, and it was found that the maximum sound pressure (pmax) and maximum OASPL (OASPLmax) have linear and logarithmic relationships with roll rate, respectively. This law holds for both left- and right-roll states. Finally, four cases of specific roll angles were conducted for comprehensive comparison studies. It was found that transient roll maneuvers intensify the interaction strength on the rolling side while weakening the interaction strength on the other side, which is closely linked to the formation mechanism of “Super-BVI noise.”
Identification of critical nodes in supply chain networks
Authors: Hua Zhen , Xia Yongxiang , Chen Yucheng , Sun Weigang
Published: January 2025

In a supply chain network (SCN), the failure of one node may result in cascading failures and lead to the paralysis of the entire network. The accurate identification of the critical nodes in a SCN is important for securing the supply chain. This study proposes a new method for identifying critical nodes in SCNs based on the topological and functional characteristics of SCNs. The effectiveness of this method is verified using an underloaded cascade failure process. A comparison with the results obtained from other critical node identification methods confirms that the proposed method could effectively identify the key nodes in the SCN. Thus, this study provides a more objective and accurate method for evaluating the importance of enterprise nodes in SCNs.
Coupling characteristics of optical skyrmions based on localized spoof plasmons (LSP)
Authors: Sun Xiaoqiao , Ni Songmei , Guo Longfei , Zhi Ting , Wang Jin , Xue Junjun , Chen Lin , Tao Tao , Tao Zhikuo
Published: January 2025

In this work, we theoretically investigate the coupling characteristics of optical skyrmions based on localized spoof plasmons (LSPs). First, the single LSP optical skyrmion is realized and resonance modes attributed to different topological features are analyzed. Second, the coupling effect is observed through decreasing the distance between the adjacent LSP optical skyrmions. The coupling LSP optical skyrmions can preserve the topological behaviors, and particularly, three coupling modes (mode-a, mode-b, and mode-c) can be observed. Mode-a presents uniform magnetic field distributions, while mode-b and mode-c can be observed with asymmetric magnetic field distributions. Finally, the ten-coupling LSP optical skyrmions supported by space-coiling cylinders and square structures are realized and the robust topological features are discussed. The results may contribute to the future investigation on designing optical skyrmion crystals and advanced optical devices.
Hydroxysilylene (HSi–OH) in the gas phase
Authors: Herman Tyler J. , Sunahori Fumie X. , Smith Tony C. , Clouthier Dennis J.
Published: January 2025

The hydroxysilylene (HSiOH) molecule has been spectroscopically identified in the gas phase for the first time. This highly reactive species was produced in a twin electric discharge jet using separate precursor streams of 16O2/18O2 and Si2H6/Si2D6, both diluted in high pressure argon. The strongest and most stable laser induced fluorescence (LIF) signals were obtained by applying an electric discharge to each of the precursor streams and then merging the discharge products just prior to expansion into vacuum. Bands of the Ã1A–X~1A′ electronic transition of HSiOH were found in the 455–420 nm region, and single vibronic level emission spectra showed only transitions attributable to the trans-hydroxysilylene ground state isomer. High resolution, rotationally resolved spectra were obtained for the 0-0 bands of HSi16OH and HSi18OH. The rotational constants were used to obtain ground and excited state molecular structures of HSiOH, with some necessary constraints. The derived ground state structure is trans-HSiOH, with geometric parameters similar to theoretical predictions from the literature. In the excited state, a skew-HSiOH structure was obtained with a dihedral angle of 102°. Our own CASSCF/aug-cc-pVTZ calculations predict a similar excited state skew geometry. The lack of odd quantum number changes in the torsional mode in emission and our difficulties in obtaining DSiOD spectra, despite considerable effort, all suggest that further experimental and theoretical efforts will be necessary to thoroughly understand the electronic spectrum of hydroxysilylene.
A novel functionalized nanoparticle for inhibiting asphaltene precipitation and deposition
Authors: Jafarbeigi Ehsan , Sahraei Eghbal , Maroufi Khaled
Published: January 2025

During petroleum production, flow assurance becomes a critical concern when asphaltene precipitation (AP) and deposition (AD) occur. Researchers have recently turned their attention to nanotechnology as a means to prevent and repair damage caused by AP and AD. This study introduces an effective inhibitor named GONEDA (graphene-oxide-N(1-naphthyl)-ethylenediamine) for asphaltene precipitation. The synthesis of functionalized nanoparticle was carried out using Hummer's technique. Subsequently, the synthesized nanoparticle was characterized through various experiments including x-ray diffraction, transmission electron microscopy, field emission-scanning electron microscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, and Brunauer–Emmett–Teller analyses. These experiments have confirmed GONEDA's unique structural properties, such as large surface area, which enhance its ability to adsorb asphaltene molecules. Batch adsorption tests were conducted to measure the adsorption capacity and efficiency of nanoparticles toward asphaltene molecules. Additionally, the indirect method was employed to detect the onset point of AP and quantify the amount of precipitated asphaltene based on differences in the optical properties of the supernatant fluid. Findings indicate that increasing the concentration of GONEDA nanoparticles leads to a decrease in their capacity but an increase in efficiency. The abundance of oxygen atoms within the GONEDA structure allows preferential adsorption of asphaltene molecules, resulting in a favorable effect on delaying AP. Specifically, compared to reference synthetic oils, the newly developed nanoparticles delayed the onset of AP by approximately 26%, 20%, and 8% for the oils containing 1000, 3000, and 5000 ppm of asphaltene, respectively. Furthermore, the presence of GONEDA NPs decreased the amount of precipitated asphaltene. These results demonstrate significant potential for field-testing, despite the laboratory-scale nature of the experiments.
Research on high-speed water entry similarity of multiscale vehicle based on two-parameter compensation of atmospheric pressure–density
Authors: Fan Shiqi , Yao Xiongliang , Ma Guihui , Wei Ran , Yin Qiang , Yu Zhichao , Jin Youwei
Published: January 2025

The atmospheric pressure and density are important factors affecting the water entry cavity and load characteristics of the vehicle. However, it is difficult to take into account the equivalent simulation of the two in the scaled-down test. The use of atmospheric pressure–density two-parameter compensation may become a key means to achieve accurate scale similarity. In this paper, the evolution of the water entry cavity and the similarity of impact loads for multiscale models in different environments are studied. Aiming at the problem that the similarity conditions are difficult to meet in small-scale model test, a distortion compensation correction method is proposed. The results show that under normal pressure environment, as the scale ratio decreases, the cavity surface closes in advance, and the slamming load gradually decreases. Under reduced pressure environment, the influence of the “scale effect” is significantly reduced. As the pressure decreases, the cavity surface closure phenomenon is weakened, and the cushioning effect of the air cushion is reduced, resulting in an increase in the slamming load. Quantitative analysis shows that the atmospheric pressure mainly affects the pressure disturbance trend in the cavity, while the atmospheric density determines the scale of the cavity and the size of the model load. By adjusting the pressure and density parameters, the prediction deviation of the small-scale model test on the disturbance time of the prototype reentrant jet pressure can be controlled within 2.4%.
Dynamic behavior of ultrasonic frequency pulsed current-assisted gas metal arc welding
Authors: Cui Xuefei , Chen Ji , Li Shengli , Su Hao , Wang Lin , Wu Chuansong
Published: January 2025

Investigating ultrasonic frequency pulsed current (UFPC)-assisted welding is crucial owing to its significant advantages over traditional welding methods, including enhanced weld quality, reduced defects, and increased efficiency. This study elucidated the generation mechanism of arc ultrasonic waves influenced by UFPC through theoretical derivation. A microscopic model of arc plasma under the influence of UFPC was developed, and the equations governing the thermophysical properties of the plasma were theoretically derived and calculated. A three-dimensional numerical simulation model was developed to analyze the dynamic behavior of arc plasma and molten metal in UFPC-assisted gas metal arc welding (UFPC-GMAW). The simulation results revealed that the incorporation of UFPC increased both the maximum arc temperature and plasma velocity, resulting in a conical shape of the arc. Additionally, the maximum arc temperature amplitude decreased from 13.6% in conventional GMAW (C-GMAW) to 9.6% in UFPC-GMAW, indicating improved arc stability. The increase in electromagnetic force led to a higher droplet transfer frequency. Moreover, the weld pool in UFPC-GMAW exhibited greater weld penetration than in C-GMAW. Notably, the variations in maximum arc temperature and velocity were synchronized with UFPC, resulting in localized thermal contraction and expansion within the arc. These changes affected the arc volume and shape, leading to the excitation of ultrasonic waves. The calculated droplet size and transfer frequency were consistent with the experimental results, confirming the reliability of the models. These simulation results provide valuable guidance for engineers in designing UFPC-GMAW technology to achieve high-quality welds.
Explosive information spreading on higher-order networks: the effect of social reinforcement
Authors: Zhou Yu , Liu Yingpeng , Yuan Liang , Zhuo Youhao , Xu Kesheng , Wu Jiao , Zheng Muhua
Published: January 2025

Information spreading has been investigated for many years, but the mechanism of why the information explosively catches on overnight is still under debate. This explosive spreading phenomenon was usually considered driven separately by social reinforcement or higher-order interactions. However, due to the limitations of empirical data and theoretical analysis, how the higher-order network structure affects the explosive information spreading under the role of social reinforcement has not been fully explored. In this work, we propose an information-spreading model by considering the social reinforcement on real and synthetic higher-order networks, describable as hypergraphs. Depending on the average group size (hyperedge cardinality) and node membership (hyperdegree), we observe two different spreading behaviors: (i) The spreading progress is not sensitive to social reinforcement, resulting in the information localized in a small part of nodes; (ii) a strong social reinforcement will promote the large-scale spread of information and induce an explosive transition. Moreover, a large average group size and membership would be to the benefit of the appearance of the explosive transition. Further, we display that the heterogeneity of the node membership and group size distributions benefit the information spreading. Finally, we extend the group-based approximate master equations to verify the simulation results. Our findings may help us to comprehend the rapidly information-spreading phenomenon in modern society.
A program for modeling the RF wave propagation of ICRF antennas utilizing the finite element method
Authors: Zhang Lei-Yu , Li Yi-Xuan , Han Ming-Yue , Zhang Quan-Zhi
Published: January 2025

Controlled nuclear fusion represents a significant solution for future clean energy, with Ion Cyclotron Range of Frequency (ICRF) heating emerging as one of the most promising technologies for heating the fusion plasma. This study primarily presents a self-developed 2D Ion Cyclotron Resonance Antenna Electromagnetic Field Solver (ICRAEMS) code implemented on the MATLAB platform, which solves the electric field wave equation by using the finite element method, establishing Perfectly Matched Layer (PML) boundary conditions, and post-processing electromagnetic field data. This code can be utilized to facilitate the design and optimization processes of antennas for ICRF heating technology. Furthermore, this study examines the electric field distribution and power spectrum associated with various antenna phases to investigate how different antenna configurations affect electromagnetic field propagation and coupling characteristics.
Multiscale structural complexity analysis of neuronal activity in the suprachiasmatic nucleus: insights from tetrodotoxin-induced disruptions
Authors: Wang Ping , Gu Changgui , Yang Huijie
Published: January 2025

The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals, coordinating physiological processes with the 24-hour day-night cycle. Comprising various cell types, the SCN integrates environmental signals to maintain complex and robust circadian rhythms. Understanding the complexity and synchrony within SCN neurons is essential for effective circadian clock function. Synchrony involves coordinated neuronal firing for robust rhythms, while complexity reflects diverse activity patterns and interactions, indicating adaptability. Interestingly, the SCN retains circadian rhythms in vitro, demonstrating intrinsic rhythmicity. This study introduces the multiscale structural complexity method to analyze changes in SCN neuronal activity and complexity at macro and micro levels, based on Bagrov et al.’s approach. By examining structural complexity and local complexities across scales, we aim to understand how tetrodotoxin, a neurotoxin that inhibits action potentials, affects SCN neurons. Our method captures critical scales in neuronal interactions that traditional methods may overlook. Validation with the Goodwin model confirms the reliability of our observations. By integrating experimental data with theoretical models, this study provides new insights into the effects of TTX on neuronal complexities, contributing to the understanding of circadian rhythms.
University of percolation at dynamic pseudocritical point
Authors: Shi Qiyuan , Wei Shuo , Deng Youjin , Li Ming
Published: January 2025

Universality, encompassing critical exponents, scaling functions, and dimensionless quantities, is fundamental to phase transition theory. In finite systems, universal behaviors are also expected to emerge at the pseudocritical point. Focusing on two-dimensional percolation, we show that the size distribution of the largest cluster asymptotically approaches to a Gumbel form in the subcritical phase, a Gaussian form in the supercritical phase, and transitions within the critical finite-size scaling window. Numerical results indicate that, at consistently defined pseudocritical points, this distribution exhibits a universal form across various lattices and percolation models (bond or site), within error bars, yet differs from the distribution at the critical point. The critical polynomial, universally zero for two-dimensional percolation at the critical point, becomes nonzero at pseudocritical points. Nevertheless, numerical evidence suggests that the critical polynomial, along with other dimensionless quantities such as wrapping probabilities and Binder cumulants, assumes fixed values at the pseudocritical point that are independent of the percolation type (bond or site) but vary with lattice structures. These findings imply that while strict universality breaks down at the pseudocritical point, certain extreme-value statistics and dimensionless quantities exhibit quasi-universality, revealing a subtle connection between scaling behaviors at critical and pseudocritical points.
H-theorem at negative temperature: the random exchange model with bounds
Authors: Lucente Dario , Baldovin Marco , Puglisi Andrea , Vulpiani Angelo
Published: January 2025

Random exchange kinetic models are widely employed to describe the conservative dynamics of large interacting systems. Due to their simplicity and generality, they are quite popular in several fields, from statistical mechanics to biophysics and economics. Here, we study a version where bounds on the individual shares of a globally conserved quantity are introduced. We analytically show that this dynamic allows stationary states with population inversion, described by Boltzmann statistics at negative absolute temperature, if the conserved quantity has the physical meaning of an energy. The proposed model therefore provides a privileged system for the study of thermalization towards a negative temperature state. First, the genuine equilibrium nature of the stationary state is verified by checking the detailed balance condition. Then, an H-theorem is proven, ensuring that such equilibrium condition is reached by a monotonic increase in the Boltzmann entropy. We also provide analytical and numerical evidence that a large intruder in contact with the system thermalizes, suggesting a practical way to design a thermal bath at negative temperature.
FPGA implementation of the HL-LHC CMS Drift Tubes Level-1 Trigger algorithm
Authors: Navarro-Tobar A. , León Holgado J.
Published: January 2025

The High-Luminosity Large Hadron Collider (HL-LHC) has motivated a generalized upgrade in electronic systems across all experiments. In the new electronics architecture for the CMS (Compact Muon Solenoid) Drift Tubes detector, the trigger generation moves from on-detector ASICs to the back-end, to be carried out by top-range FPGAs. The new algorithm aims to deliver full-resolution, offline-grade performance in the reconstruction of muon segments. To achieve this objective, meeting the latency and data rate requirements, a high-speed, highly-pipelined FPGA design with several optimizations has been developed. This work describes the architecture and performance of this algorithm, as well as the challenges encountered during implementation and the solutions adopted.
High-Voltage studies in the new GE1/1 GEM station at CMS experiment
Authors: Di Fraia Carlo ,   the CMS Muon group
Published: January 2025

Part of the muon upgrade of the CMS Experiment for the High-Luminosity Large Hadron Collider consists of three new GEM stations, GE1/1, GE2/1 and ME0. The purpose of these stations is to increase the redundancy of the CMS muon spectrometer in the forward endcap regions and to extend the acceptance of the detector up to a pseudorapidity |η| ∼ 2.8 with the ME0 station. To achieve this result, these detectors must be able to withstand the background radiation of the installation environment, with a rate capability of up to 150 kHz/cm2.
The first station, GE1/1, was installed during the Long Shutdown 2. Since the start of Run 3 in 2022, GE1/1 has been active in CMS operations and data acquisition; this will be the focus of this work. The presence of high radiation in the area where the detector operates is a challenge for the High-Voltage system, since a large charge has to be handled without reducing the effective gain of the detector. This phenomenon leads to a drop in the effective voltage applied and therefore voltage compensation must be applied to have a stable gain. We quantify this effect by measuring the currents flowing in the High-Voltage system of GE1/1 detectors and comparing them with the observed particle hit-rate measured in the same chambers, as a function of LHC beam luminosity. This study, based on data provided by detectors already installed in CMS, aims to test the performance of detectors in terms of rate capability in order to help the development of the GE1/1 station and to support the development and to highlight the operational needs of the next two stations to be built, GE2/1 and ME0.
TCAD simulation of stitching for passive CMOS strip detectors
Authors: Baselga M. , Arling J-H. , Davis N. , Dingfelder J. , Gregor I.M. , Hauser M. , Hügging F. , Jakobs K. , Karagounis M. , Koppenhöfer R. , Kröninger K. , Lex F. , Parzefall U. , Sari B. , Spannagel S. , Sperlich D. , Weingarten J. , Zatocilova I.
Published: January 2025

Most of the tracking detectors for high energy particle experiments are filled with silicon detectors since they are radiation hard, they can give very small spatial resolution and they can take advantage of the silicon electronics foundries' developments and production lines.

Strip detectors are very useful to cover large areas for tracking purposes, while consuming less power per area compared to pixel sensors. The majority of particle physics experiments use conventional silicon strip detectors fabricated in foundries that do not use stitching, relying on a very small number of foundries worldwide that can provide large amounts of strip detectors. Fabricating strip detectors in a CMOS foundry opens the possibility to use more foundries and to include active elements in the strips for future productions. For the passive CMOS strip detectors project we fabricated strip detectors in a CMOS foundry using two 1 cm2 reticles that are stitched together along the wafer.
The fabricated strips stitched the reticles three and five times, and it was shown that the performance of those strips is not affected by the stitching.

This paper shows 3D TCAD simulations of the stitching area to investigate the possible effects stitching can have on the performance of the strip detectors, considering different stitching mismatches. We will show that the mismatch of stitched structures up to 1 µm does not impact the performance with TCAD simulations which agrees with the results obtained from the measurements.
Design proposal for an ionisation chamber as a secondary standard for eye lens dosimetry
Authors: Mihailescu Liviu-Cristian , González-Castaño Diego Miguel , Derlacinski Michal , Schoonjans Werner
Published: January 2025

We propose a system to directly measure Hp
(3) quantity both in calibration conditions at laboratories and at arbitrary conditions at irradiation facilities. A commercial ionisation chamber is inserted in a spherical phantom of PMMA such that the system achieves a relatively constant response in terms of Hp
(3) and matches the requirements for a secondary standard for Hp
(3) quantity. The Hp
(3) ionisation chamber was characterized in a dosimetry calibration laboratory under reference conditions and then, as a proof of concept, it was also tested in a work place field at an interventional cardiology department from a hospital. The design method and the measurement results are presented.
Development of a high-resolution, high-dynamic-range charge detector for ion beam monitoring
Authors: Adriani O. , Berti E. , Betti P. , Casaus J. , D'Alessandro R. , Detti S. , Diaz C. , Marin J. , Martinez G. , Mori N. , Pacini L. , Pizzolotto C. , Tiberio A. , Scaringella M. , Starodubtsev O. , Zampa G. , Zampa N.
Published: January 2025

We present an innovative charge detector with high
resolution and wide dynamic range designed to fulfill the
requirements of a monitoring system for a high energy ion beam. The
detector prototype, constructed using Si photodiodes and a custom
readout electronics, underwent extensive testing during HERD and AMS
beam tests at CERN SPS facilities. Initial testing showcased the
detector's exceptional performance, emphasizing both high resolution
and a dynamic range capable of measuring nuclei with atomic numbers
ranging from 1 to 80. The prototype's compatibility with fast, quasi
real-time data analysis qualifies it as an ideal candidate for
online applications. This article presents the results from the
testing phase of the prototype, highlighting its capabilities and
performance. Ongoing detector development, potential applications,
and future developments aimed at enhancing the detector's
functionality and versatility are also discussed.
Geant4-based technical simulation study of plastic scintillators for Positron Annihilation Lifetime Spectroscopy (PALS)
Authors: Boras D. , Petschke D. , Staab T.
Published: January 2025

The influence of detector setup configuration and scintillator material choice on spectrum quality in Positron Annihilation Lifetime Spectroscopy (PALS) is fundamentally acknowledged primarily by empirical observation. However, this study quantifies the effects of ultra-fast plastic scintillators (BC422Q) within a conventional collinear (180-degree) detector setup used in the laboratory using the Geant4 simulation toolkit. We examine the impact of the scintillator's dimension and geometry (truncated cone vs. cylinder) on the detection efficiency for specific gamma-ray energies (1274 keV and 511 keV) and their proportion of corrupt events such as backscattering or multiple detections. Results indicate that the selection of scintillator dimension and shape significantly enhances detection efficiency albeit with an increase in corrupt events. Furthermore, we investigate the influence on the instrument response function (IRF) of the scintillators, showing how truncated cones offer superior precision and, thus, a narrower IRF compared to cylindrical shapes.

Additionally, the effect of the sample material itself, in the case of a truncated cone as the scintillator shape, on the scintillator response was studied. It is observed that with an increasing atomic number of the sample the detection efficiency substantially decreases while the proportion of corrupt events also diminishes. Despite the sample material's influence on the energy of gamma-quanta interacting with the scintillator, no measurable impact on the IRF was detected for the chosen windows of the pulse height spectra.

This investigation encourages a profound examination of the influences on spectrum quality in PALS measurements using Geant4 as a simulation tool highlighting the critical balance between detection efficiency and corrupt event frequencies.