bluuebunny/crossref_metadata_2025_split huggingface dataset:
SASHIMI-SIDM: semi-analytical subhalo modelling for self-interacting dark matter at sub-galactic scales
Authors: Ando Shin'ichiro , Horigome Shunichi , Nadler Ethan O. , Yang Daneng , Yu Hai-Bo 
Published: February 2025

Abstract
We combine the semi-analytical structure formation model, SASHIMI, which predicts subhalo populations in collisionless, cold dark matter (CDM), with a parametric model that maps CDM halos to self-interacting dark matter (SIDM) halos. The resulting model, SASHIMI-SIDM, generates SIDM subhalo populations down to sub-galactic mass scales, for an arbitrary input cross section, in minutes. We show that SASHIMI-SIDM agrees with SIDM subhalo populations from high-resolution cosmological zoom-in simulations in resolved regimes. Crucially, we predict that the fraction of core-collapsed subhalos peaks at a mass scale determined by the input SIDM cross section and decreases toward higher halo masses, consistent with the predictions of gravothermal models and cosmological simulations. For the first time, we also show that the core-collapsed fraction decreases toward lower halo masses. While the dependence of the collapse time on mass and concentration implies such behaviour, our semi-analytical approach allows us to quantify and illustrate this trend clearly across the full mass spectrum of subhalos, including for subhalo masses below the resolution limit of any current cosmological SIDM simulation. As a proof of principle, we apply SASHIMI-SIDM to predict the boost to the local dark matter density and annihilation rate from core-collapsed SIDM subhalos, which can be enhanced relative to CDM by an order of magnitude for viable SIDM models. Thus, SASHIMI-SIDM provides an efficient and reliable tool for scanning SIDM parameter space and testing it with astrophysical observations. The code is publicly available at https://github.com/shinichiroando/sashimi-si.
Traces of quantum fuzziness on the black hole shadow and particle deflection in the multi-fractional theory of gravity
Authors: Pantig Reggie C. 
Published: February 2025

Abstract
In this paper, we investigate the properties of black holes within the framework of multi-fractional theories of gravity, focusing on the effects of q-derivatives and weighted derivatives. These modifications, which introduce scale-dependent spacetime geometries, alter black hole solutions in intriguing ways. Within these frameworks, we analyze two key observable phenomena - black hole shadows and particle deflection angle in the weak field limit - using both analytical techniques and observational data from the Event Horizon Telescope (EHT) for M87* and Sgr A*. The study from $q$-derivative formalism reveals that the multi-scale length $\ell_*$ influences the size of the black hole shadow in two ways, and modifies the weak deflection angle. Constraints on $\ell_*$ are derived from the EHT observations, showing significant deviations from standard Schwarzschild black hole predictions, which range from $10^{9}$ to $10^{10}$ orders of magnitude. Additionally, the weak deflection angle is computed using the non-asymptotic generalization of the Gauss-Bonnet theorem, revealing the effects of finite-distance and multi-scale parameters. Using the Sun for Solar System test, the constraints for $\ell_*$ range from $10^{8}$ to $10^{9}$ orders of magnitude. Results from the weighted derivative formalism generates a dS/AdS-like behavior, where smaller deviations are found in the strong field regime than in the weak field regime. The results suggest that while these effects are subtle, they provide a potential observational signature of quantum gravity effects. The findings presented here contribute to the broader effort of testing alternative theories of gravity through black hole observations, offering a new perspective on the quantum structure of spacetime at cosmological and astrophysical scales.
XGboost for Predicting Chemical Abundances of Open Clusters in LAMOST DR11 LRS
Authors: ruyuan zhang , Wu Chengyuan , Chen Xing Jian , Wang Luqian , Zha Shuai , Guo Sufen , Han Zhanwen 
Published: February 2025

Abstract
The 11th data release of the LAMOST survey provides fundamental stellar param-&#xD;eters but lacks detailed abundance measurements for α-elements, crucial for understanding&#xD;stellar populations and Galactic chemical evolution. In this study, we derive the abundances of&#xD;oxygen (O), magnesium (Mg), silicon (Si), calcium (Ca), and titanium (Ti) for over 6.8 mil-&#xD;lion stars using LAMOST DR11 low-resolution spectra. To ensure reliable measurements,&#xD;we select 1,086 OCs spanning a broad range of ages and apply Monte Carlo sampling for&#xD;accurate abundance estimates. Additionally, we utilize over 30,000 stars from the GALAH&#xD;DR4 catalog to train an XGBoost model for extracting α-element abundances from LAMOST&#xD;DR11 spectra. Bayesian linear regression is employed to analyze the compositional distribu-&#xD;tion across the Galactic disk and infer chemical gradients as a function of Galactocentric&#xD;distance. Our results indicate a general increase in chemical abundances with Galactocentric&#xD;distance, with oxygen showing the steepest gradient. The abundance patterns of Mg, Si, Ca,&#xD;and Ti are consistent with previous studies, yet exhibit distinct differences, providing new&#xD;insights into Galactic chemical evolution
Study on Microstructure and Properties of High-strength-toughness Al-9Si-xCu-yMg Alloy
Authors: Haoyu Bai , Zhifeng Zhang , Yanlin Guo , Yabao Wang 
Published: February 2025

Abstract
The existing Al-Si-Cu-Mg alloys cannot meet the needs of new energy automobile parts with low cost and high performance due to difficulty in reconciling high strength and low plasticity. In this study, a systematic research method combining thermodynamic calculation and experiment was adopted, and alloy composition, microstructure and mechanical properties of the Al-9Si-2.5Cu-0.5Mg alloy were investigated by adjusting the content of Cu, Mg and the heat treatment process. The results show that, as Cu and Mg content increase, the strength of the alloy increases first and then decreases, but the elongation decreases significantly. When the Cu content is 2.5% and the Mg content is 0.5%, there exists an optimal combination between the strength and elongation, and the tensile strength of 387MPa, and elongation of 4.15% are achieved. The microstructure and mechanical properties of Al-9Si-2.5Cu-0.5Mg alloy can be improved by adding modifier Al-Sr, grain refiner Al-5Ti-B and appropriate heat treatment process, and the improvement of the comprehensive mechanical properties mainly benefits from the fine grain strengthening and the precipitation strengthening. The research work is expected to provide theoretical basis and practical guidance for the optimal design of high-strength-toughness Al-Si-Cu-Mg alloy.
Finite Element Analysis of Welding and Heat Treatment of TC4 Titanium Alloy Pressure Vessels
Authors: Chen Fenglin , Zhang Aifeng , Yu Xiangyu , Ge Keke 
Published: February 2025

Abstract
Finite element analysis was carried out for the welding and heat treatment process of TC4 titanium alloy pressure vessel, aiming at revealing the distribution characteristics of welding residual stress and its changing law in the heat treatment process. By establishing a two-dimensional axisymmetric welding model, and considering the material properties, boundary conditions, heat source model and analysis methods, the temperature and stress fields in the welding process are successfully simulated.Based on the results of the post-welding stress field, the time-hardened creep model is quoted for the finite element calculations of the post-welding heat treatment process, and the effect of creep effect on the residual stresses of welded annulus is investigated, the results show that: the stress characteristics of the girth weld of the TC4 titanium alloy pressure vessel are obvious. The axial residual stress shows a tensile - compressive - tensile distribution along the thickness direction, while the hoop residual stress is a high tensile stress in the near-weld and heat affected zone, and the stress peak even exceeds the yield strength of the material; By comparing the heat treatment schemes considering and not considering the creep mechanism, it is found that the heat treatment introducing the creep mechanism significantly reduces the residual stress in the weld area. Among them, the hoop stress decreases by 80% and the axial stress decreases by 50%, and the stress distribution is more uniform, effectively alleviating the stress concentration phenomenon of the weld. In addition, the rebound amount of the residual stress in the cooling stage of the heat treatment scheme considering the creep mechanism is small. This study indicates that the creep mechanism plays a dominant role in eliminating residual stresses during heat treatment.
Advancements in the research of nanotwinned ceramic coatings
Authors: Yang Sen , Li Yujing , Song Ruili , Tian Caili , Guo Tao , Pang Xiaolu 
Published: February 2025

Abstract
Ceramic coatings, especially transition metal nitrides, are widely applied as protective coatings on wear surfaces. The increasing demand for mechanical performance and thermal stability in high-strength applications has driven the development of advanced coatings with complex microstructures and composition designs. Studies have shown that the introduction of nanotwin structures can simultaneously enhance the mechanical and thermal stability of ceramics. Despite the extremely high stacking fault energy, it has been demonstrated that fabricating nanotwins into ceramic coatings is feasible. This paper reviews recent studies on the formation mechanism, mechanical properties, and thermal stability of nanotwinned ceramic coatings. We anticipate that the latest advancements in nanotwinned ceramics research will provide a broader perspective on improving their performance, laying the foundation for developing ceramic coatings with high strength, excellent fracture toughness, and enhanced thermal stability. Additionally, it offers theoretical guidance for twin research in ultra-high stacking fault energy materials.
Mitigating multiple single-event upsets during deep neural network inference using fault-aware training
Authors: Vinck Toon , Jonckers Naïn , Dekkers Gert , Prinzie Jeffrey , Karsmakers Peter 
Published: February 2025

Abstract
Deep neural networks (DNNs) are increasingly used in safety-critical applications. Reliable fault analysis and mitigation are essential to ensure
their
functionality in harsh environments that contain high radiation levels. This study analyses the impact of multiple single-bit single-event upsets in DNNs by performing fault injection at the level of a DNN model. Additionally, a fault-aware training (FAT) methodology is proposed that improves the DNNs' robustness to faults without any modification to the hardware. Experimental results show that the FAT methodology improves the tolerance to faults up to a factor 3.
Optimisation and validation of power delivery networks for multi-gigabit data links
Authors: Martina F. , Biereigel S. , Baron S. , Baszczyk M. , Klekotko A. , Kulis S. , Moreira P. , Soos C. 
Published: February 2025

Abstract
The performance of ASICs for high-bandwidth communications is heavily influenced by the interconnection with the hosting module and paired devices, including the bonding scheme and the PCB layout. The recent validation campaign of the 25.6 Gbps DART28 transmitter has highlighted that a coordinated simulation and design of the power delivery network is required to achieve satisfactory performance. In this context, the results obtained from variants of the test-bench carrier boards are compared, examining how the optimisation of the layout and bondwire placement leads to improvements of the serial link characteristics. Electromagnetic simulations support the analysis and provide a framework for developing the subsequent versions.
Design of the OBELIX monolithic CMOS pixel sensor for the Belle II vertex detector upgrade
Authors: Boudagga R. , Auguste D. , Babeluk M. , Barbero M. , Barrillon P. , Baudot J. , Bergauer T. , Bernlochner F. , Bertolone G. , Bespin C. , Bettarini S. , Bevan A. , Bona M. , Bonis J. , Bosi F. , Breugnon P. , Buch Y. , Casarosa G. , Corona L. , Dingfelder J. , Dorokhov A. , Dujany G. , Federici L. , Fernandez Prieto A. , Finck C. , Forti F. , Fougeron D. , Frey A. , Gabrielli A. , Gaioni L. , Gallas Torreira A. , Gao X. , Giroletti S. , Gong J. , Hara K. , Higuchi T. , Himmi A. , Howgill D. , Hu-Guo C. , Irmler C. , Jeans D. , Kaliyar A.B. , Karagounis M. , Kishishita T. , Krüger H. , Kumar A. , Lacasta C. , Marinas C. , Massa M. , Massaccesi L. , Mazorra de Cos J. , Minuti M. , Moggi A. , Molina-Bueno L. , Mondal S. , Morel F. , Nakamura K.R. , Okazaki Y. , Onuki Y. , Pangaud P. , Peinaud Y. , Pham H. , Pilsl B. , Ratti L. , Re V. , Riceputi E. , Ripp-Baudot I. , Rizzo G. , Schall L. , Schwanda C. , Schwenker B. , Schwickardi M. , Sefri R. , Serrano J. , Song W. , Stavroulakis P. , Traversi G. , Valin I. , Vobbilisetti V. , Vogt M. , Wang S. , Winter M. , Xu D. 
Published: February 2025

Abstract
Targeting a peak luminosity of 6 × 1035 cm-2s-1, the Belle II experiment at the
SuperKEKB
in Japan is considering an upgrade of its interaction region. This upgrade involves the vertex detector, which will be replaced by a new fully pixelated vertex detector (VTX). A monolithic CMOS pixel sensor named OBELIX (Optimized BELle II pIXel) is proposed to be used in the VTX. Based on the existing TJ-Monopix2 chip initially developed for the ATLAS Inner Tracker
(ITk) upgrade, OBELIX is designed in a 180 nm CMOS process with an improved pixel matrix and additional functionalities such as new on-chip voltage regulators and digital periphery. This paper will review the overall design of the VTX and the OBELIX sensor.
Effect of a nonadiabatic magnetic field on the amplitude of cyclotron motion
Authors: Etxebarria J. , Oliver C. , Pikin A. 
Published: February 2025

Abstract
This analysis extends the previously published study of the effect of a nonadiabatic magnetic field on the electron beam for different electron beam currents. Specifically, it presents 2-dimensional maps of relative amplitudes of radial beam oscillations in a space defined by nonadiabatic magnetic field strengths and electron beam currents. As before, the electron gun and the drift region are immersed in a uniform magnetic field to avoid distorting the cyclotron motion. Unlike in the previous paper, the cathode of the electron gun has a radius of 3 mm, which is more suitable for EBIS applications. These maps show the operating range of such an optical system with a nonadiabatic magnetic field and the options of optimizing the nonadiabatic coil strength and position for different electron beam currents.
Intrinsic energy resolution of LaBr3(Ce) crystal
Authors: Feng Pei-Yi , Sun Xi-Lei , An Zheng-Hua , Wang Cheng-Er , Zhang Da-Li , Li Xin-Qiao , Zheng Chao , Xiong Shao-Lin , Lu Hong 
Published: February 2025

Abstract
This study aims to provide an accurate estimation of the intrinsic resolution of LaBr3(Ce) crystal through a combination of experimental and simulation methods. We re-analyzed the data from previous Wide-Angle Compton Coincidence (WACC) and Hard X-ray Calibration Facility (HXCF) experiments, conducted PMT Single-Photoelectron Calibration (SPEC) and radial non-uniformity (also called Spot Scanning, SS) experiments to acquire new data, and combined these results with Geant4 simulations to isolate the contribution of each physical process to the total energy resolution, thereby allowing for a precise estimation of the scintillator's intrinsic resolution. For 100 keV X-rays, the total energy resolution of LaBr3(Ce) crystal is 3.99%± 0.04% (expressed as 1-σ), with statistical fluctuations and intrinsic resolution as the main components, contributing 2.47%± 0.00% and 3.06%± 0.06%, respectively. We identify two main sources of intrinsic resolution: one primarily due to non-proportional scintillation, contributing 2.28%± 0.00%, and the other due to fluctuations in the energy transfer process, contributing 2.04%± 0.08%. We quantified six components of the total energy resolution and reconstructed the photon response using Geant4. The consistency between the reconstructed relative light yield and the experimental measurements validated the mass model of the LaBr3(Ce) detector used in the simulations.
Fast data packet sorting method based on FPGA on-chip RAM
Authors: Jiang Wei , Zhang Jian-Hua , Cao Xiao-Feng , Yang Bo , Wang Wen-Tao 
Published: February 2025

Abstract
The study of fast sorting algorithms has long been an
enduring research focus. Traditional sorting algorithms often suffer
from high time complexity, typically staying at (n
2) or
O(n × log2
n). Given the parallel processing advantages of
field programmable gate array (FPGA), it has become a popular
platform for algorithm acceleration. However, existing hardware
sorting acceleration methods remain rooted in classical software
algorithm models, merely leveraging hardware for parallel execution,
without fully exploring the unique architecture and resources of
FPGAs. In response, this paper proposes a fast sorting method that
leverages on-chip random-access memory (RAM), uniquely tailored to
FPGA characteristics. First, a mapping is established between the
key fields of data packets and the on-chip RAM addresses. Then, the
data packets are written into RAM based on this mapping, which also
inevitably result in some RAM addresses being left empty. Next, a
indicator register is maintained to dynamically track which RAM
addresses are empty. Finally, the data packets are sequentially read
from RAM addresses, and the indicator register helps skip empty
addresses to enhance readout efficiency. Due to the inherent
ordering of RAM addresses, the data packets become naturally ordered
after read. Simulation results confirm that this method can reduce
the time complexity to O(n), providing a novel solution for fast
sorting in real-time data streams.
Design and Simulation of a Logistically Constrained High-Latitude, Low-Altitude Stratospheric Aerosol Injection Scenario in the Energy Exascale Earth System Model (E3SM)
Authors: Wheeler Lauren , Wagman Benjamin , Smith Wake , Davies Peter , Cook Benjamin , Brunell Sarah , Glen Andrew , Hackenburg Diana , Lien Jessica , Shand Lyndsay , Zeitler Todd 
Published: February 2025

Abstract
The Arctic is warming faster than the rest of the globe, posing risks to climate tipping elements such as the collapse of the Greenland Ice Sheet, winter Arctic sea ice loss, weakening of the Atlantic Meridional Overturning Circulation, and permafrost collapse. Stratospheric Aerosol Injection (SAI) has shown potential to ameliorate these effects by reducing surface temperatures. Due to the potential for an asymmetric hemispheric response in precipitation, Arctic-only SAI is not recommended. Given the challenges associated with an Antarctic SAI program, including the lack of nearby large airports, however, we designed and simulated an Arctic-only logistically constrained SAI scenario, considering limitations imposed by factors affecting the planning, execution, and management of operations. Our scenario is constrained by aircraft development and delivery timelines. SAI deployment begins in 2032 and increases to a maximum annual injection of 6.7 TgSO2 by 2053 through 2070. The scenario is simulated in a modified version of the Energy Exascale Earth System Model (E3SMv2). Results indicate that Arctic-only SAI can reduce Northern Hemisphere temperatures and slow sea ice loss, though the early years of deployment may show limited cooling due to low ramp-in injection magnitudes. The Arctic-only SAI introduces minimal impact on Southern Hemisphere temperatures but significant shifts in the hydrologic cycle, particularly around the equator. Southern Hemisphere changes are low within the first two decades, suggesting that asymmetries in Arctic-only SAI deployment could be sustained without severe adverse climate impacts for the first couple of decades. These asymmetries matter given the challenges associated with an Antarctic SAI program. Our findings underscore the necessity of incorporating logistical constraints on deployment and the need for multi-model assessments in the evaluation of polar SAI scenarios. This approach would ensure a strong scientific understanding of polar SAI and facilitates policy and decision-maker understanding of the risks and benefits of SAI.
Provable Optimality of the Square-Tooth Atomic Frequency Comb Quantum Memory
Authors: Zang Allen , Suchara Martin , Zhong Tian 
Published: February 2025

Abstract
Atomic frequency comb (AFC) quantum memories are a promising technology for quantum repeater networks because they enable multi-mode, long-time, and high-fidelity storage of photons with on-demand retrieval. The optimization of the retrieval efficiency of an AFC memory is important because it strongly impacts the entanglement distribution rate in quantum networks. Despite initial theoretical analyses and recent experimental demonstrations, a rigorous proof of the universally optimal configuration for the highest AFC retrieval efficiency has not been presented. In this paper we present a simple analytical proof which shows that the optimized square tooth offers the highest retrieval efficiency among all tooth shapes, under the physical constraint of finite optical depth of an atomic ensemble. The optimality still holds when the non-zero background absorption and the finite optical linewidth of atoms are considered. We further compare square, Lorentzian and Gaussian tooth shapes to reinforce the practical advantage of the square-tooth AFC in retrieval efficiency. Our proof lays rigorous foundation for the recipe of creating optimal AFC under realistic experimental conditions.
Rapid modeling and ECU testing of a hydrogen free-piston engine generator
Authors: Chen Xin , Xu Zhaoping , Luo Yue , Liu Liang 
Published: February 2025

Abstract
With the advantages of cleanliness, high power density, and simple structure, the hydrogen free-piston generator (FPEG) has emerged as a promising range extender in new energy vehicles. Despite its excellent application prospects, the development of the electronic control unit (ECU) for the FPEG system remains challenging and time-consuming. Therefore, it is necessary to build a system model for the ECU test. Traditional modeling methods have some problems, such as slow simulation speed and low accuracy. This article proposes a method for building a rapid system model. The rapid system model has been built based on the hydrogen free-piston engine generator system. Afterward, the test cases for the ECU test were generated based on the constructed model. Several typical operating conditions of the system have been considered. Include cold start conditions, handling of fire anomalies, and stable operating conditions. Finally, the feasibility of the model is verified through hardware-in-the-loop (HIL) testing. The result shows that the rapid system model can be used for the ECU test. Its simulation time was reduced by approximately 78% compared to the original model.