bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent progress on topological semimetal IrO2: electronic structures, synthesis, and transport properties
Authors: Zhang T X , Coughlin A L , Lu Chi-Ken , Heremans J J , Zhang S X 
Published: April 2024

Abstract
5d transition metal oxides, such as iridates, have attracted significant interest in condensed matter physics throughout the past decade owing to their fascinating physical properties that arise from intrinsically strong spin-orbit coupling (SOC) and its interplay with other interactions of comparable energy scales. Among the rich family of iridates, iridium dioxide (IrO2), a simple binary compound long known as a promising catalyst for water splitting, has recently been demonstrated to possess novel topological states and exotic transport properties. The strong SOC and the nonsymmorphic symmetry that IrO2 possesses introduce symmetry-protected Dirac nodal lines (DNLs) within its band structure as well as a large spin Hall effect in the transport. Here, we review recent advances pertaining to the study of this unique SOC oxide, with an emphasis on the understanding of the topological electronic structures, syntheses of high crystalline quality nanostructures, and experimental measurements of its fundamental transport properties. In particular, the theoretical origin of the presence of the fourfold degenerate DNLs in band structure and its implications in the angle-resolved photoemission spectroscopy measurement and in the spin Hall effect are discussed. We further introduce a variety of synthesis techniques to achieve IrO2 nanostructures, such as epitaxial thin films and single crystalline nanowires, with the goal of understanding the roles that each key parameter plays in the growth process. Finally, we review the electrical, spin, and thermal transport studies. The transport properties under variable temperatures and magnetic fields reveal themselves to be uniquely sensitive and modifiable by strain, dimensionality (bulk, thin film, nanowire), quantum confinement, film texture, and disorder. The sensitivity, stemming from the competing energy scales of SOC, disorder, and other interactions, enables the creation of a variety of intriguing quantum states of matter.
Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China
Authors: Yang Fanqiaochu , Gao Linfeng 
Published: April 2024

Abstract
Computed tomography (CT) is extensively utilised in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of paediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of paediatric CT, we investigated the radiation dose level for paediatric CT in Shanghai. In this survey, a total of 3061 paediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analysed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan, the DRLs of CTDIvol were from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvol were from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvol were from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60% lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions (P < 0.001). In conclusion, there was still potential for reducing radiation dose of paediatric CT, emphasising the urgent need for optimising paediatric CT dose in Shanghai.
Method for the P-wave arrival pickup of rock fracture acoustic emission signals under strong noise
Authors: Luo Junhua , Bespal’Ko Anatoly Alekseevich , Lu Di , Li Baocheng 
Published: April 2024

Abstract
This research aimed to investigate the accuracy of picking of P-wave arrival times in rock fracture acoustic emission signals. In order to simulate the mining scenario, Gaussian white noise and pulse noise were added to the data collected in the laboratory. Complete ensemble empirical mode decomposition with adaptive noise + Wavelet (CEEMDAN + Wavelet) was improved in this paper, where the Spearman rank correlation coefficient was adopted to effectively select intrinsic mode functions for denoising which retained the inherent characteristics of the rock fracture signal. The absolute amplitude and energy change rate of the envelope signal, calculated based on the Hilbert transform, were used as the input of the short term average/long term average (STA/LTA) normalization algorithm to pickup the P-wave arrival time. The reliability of this method was tested on 30 groups of recorded rock fracture laboratory data and 60 groups of added noise data. Taking the manual pickup results as the standard, the errors of CEEMDAN + Wavelet + STA/LTA + AIC (Akaike information criterion) method with the absolute amplitude of the signal as the input are all within 10 ms, and 86.67% of the results are within 5 ms. The method proposed in this paper effectively addressing the issue of false pickup caused by the sensitivity of AIC and traditional STA/LTA method for strong noise, and achieving relatively high accuracy and stability in processing low signal-to-noise ratio signals. This work contributes to monitor microscopic changes in rock bodies and is of great significance for the prediction and monitoring of geological disasters.
A first-principles study of HfB2 anisotropic surface stability and its oxygen adsorption behavior
Authors: Cheng Gong , Cao Shengzhu , Zhang ZhenZhen , Xiong Yuqing , Zhou Hui , He Yanchun , Zhang Kaifeng , Gao Hengjiao 
Published: April 2024

Abstract
In this work, the HfB2 anisotropic surface stability, and the adsorption behavior of oxygen molecule on the most likely exposed HfB2 surface were investigated based on density functional theory. The study found that the HfB2(0001) surface terminated by Hf (labeled as: Hf-(0001)) is more stable, and more likely interact with oxygen. By rotating the oxygen molecule orientation and changing the adsorption site, all possible high and low-symmetry adsorption configurations are considered. The results show that the low symmetry structure is unstable, and eventually turn into the high symmetry ones. For the highly symmetric structures, oxygen molecule tends to be adsorbed in parallel, and the dissociated oxygen molecule tends to be located at the bridge and hollow site of the Hf-(0001) surface, and there is no energy barrier to this process. Charge density difference and partial density of states proved that oxygen absorbed structures present similar electronic interaction characteristics, and oxygen adsorption process mainly affects the Hf atom at the outmost layer of the Hf-(0001) plane. Oxygen atoms bind to the Hf-(0001) surface mainly in the form of ionic bonds and covalent bonds, originating from the orbital hybridization of O-p and Hf-d. The oxidation of HfB2 starts from the interaction between oxygen and Hf.
Multi-branch myocardial infarction detection and localization framework based on multi-instance learning and domain knowledge
Authors: Li Xinyue , Huang Yangcheng , Ning Yixin , Wang Mingjie , Cai Wenjie 
Published: April 2024

Abstract

Objective. Myocardial infarction (MI) is a serious cardiovascular disease that can cause irreversible damage to the heart, making early identification and treatment crucial. However, automatic MI detection and localization from an electrocardiogram (ECG) remain challenging. In this study, we propose two models, MFB-SENET and MFB-DMIL, for MI detection and localization, respectively. Approach. The MFB-SENET model is designed to detect MI, while the MFB-DMIL model is designed to localize MI. The MI localization model employs a specialized attention mechanism to integrate multi-instance learning with domain knowledge. This approach incorporates handcrafted features and introduces a new loss function called lead-loss, to improve MI localization. Grad-CAM is employed to visualize the decision-making process. Main Results. The proposed method was evaluated on the PTB and PTB-XL databases. Under the inter-patient scheme, the accuracy of MI detection and localization on the PTB database reached 93.88% and 67.17%, respectively. The accuracy of MI detection and localization on the PTB-XL database were 94.89% and 85.83%, respectively. Significance. Our method achieved comparable or better performance than other state-of-the-art algorithms. The proposed method combined deep learning and medical domain knowledge, demonstrates effectiveness and reliability, holding promise as an efficient MI diagnostic tool to assist physicians in formulating accurate diagnoses.
Neutralized, intense-ion beams for fusion
Authors: Wessel Frank J , Egly Andrew , Rogers Joel 
Published: April 2024

Abstract
A charge- and current-neutralized, intense-ion beam (IIB) will propagate undeflected in a magnetized plasma by the

E
×
B

, or diamagnetic, drift for a distance large compared to the beam-ion gyro-radius. This propagation occurs because of collective plasma effects when the beam-energy density is sufficient to sustain the polarization-electric field, or diamagnetic-screening currents. Our principal interest is the

E
×
B

drift, with

β
=

E

beam

/

E

field

<
1

. IIBs are characterized by parameters in the range: 0.1–2 MeV ion energy, 1–100 MA m−2 ion-current density, and 17–350 kW average power produced on repetitively-pulsed systems. Multi-MW average-beam power is possible with appropriate modifications to the power supply and ion-source/accelerator. IIBs can be focused geometrically, and/or magnetically, to spot sizes of the order of a few cm’s and their angular divergence is typically, ∼15 mRadians, suitable for long-range propagation in a vacuum beam-line. IIBs lose energy and momentum in the same manner as particles injected by a neutral-beam injector (NBIs), hence could be useful for fusion applications, including: heating, current drive, fueling, profile modifications, etc and such applications have yet to be thoroughly studied. Summarized here are the physical principles accounting for IIB propagation; ion-source designs used to produce the IIB; and pulsed-power methods for energizing the IIB accelerator. This technology base informs scalable metrics for the ion-source/accelerator (excluding the HV power supply and interconnects) used in a conceptual injector that provides the same ion energy and injected power (1 MeV, 17 MW) as NBIs used on ITER. A comparison indicates that the IIB injector would be much smaller in size, lower cost, and have much greater efficiency, while also providing for real-time modulation of the beam energy and intensity and the use of small-diameter injection ports that could minimize fuel contamination and magnetic-field leakage between the IIB injector and tokamak.
Understanding the trap-induced frequency dispersion in the C–V curve of AlGaN/GaN hetero-structure
Authors: Nautiyal Priyanka , Pande Peyush , Kundu Virender , Joshi Vikas , Chaturvedi Mayank 
Published: April 2024

Abstract
This article investigates the trapping mechanism in AlGaN/GaN heterostructure. For our study, the traps within the AlGaN layer are introduced at the interface and near the interface of AlGaN/GaN, in the SILVACO TCAD tool. Frequency-dependent capacitance-Voltage (CVF) curves are obtained to study the impact of traps on device performance. From the CVF curve, it is found that the existence of interface traps introduces a shift in capacitance along the gate voltage axis. These traps introduce the threshold voltage (

V

TH

) shift. Furthermore, a detailed study of near-interface traps (NITs) is done based on tunneling mechanisms. For our investigation, the NITs are positioned at 0.5 nm, 1 nm, and 1.5 nm away from the AlGaN/GaN interface. The response of the NITs reduces the capacitance value in the accumulation region. The response of the NITs is explained through the capacitance charge model and border trap model. For NITs placed 0.5 nm away from the interface, the frequency dispersion in the accumulation region becomes evident. On the contrary, the dispersion reduces significantly, as the NITs goes deeper upto 1.5 nm. The results indicate that the NITs nearer to the interface respond to high frequencies. Further, the temperature dependent capacitance–voltage analysis is done for both interface and NITs, to understand the effect of temperature on frequency dispersion.
Realization of an ultra-scaled novel Ga2O3 FinFET for sub-terahertz applications
Authors: Goyal Priyanshi , Kaur Harsupreet 
Published: April 2024

Abstract
This study involves in-depth simulations focused on gate-electrode and channel-doping engineering in ultra-scaled Ga2O3 FinFETs. Silvaco TCAD software was employed as a simulation tool to explore the suitability of these designs for sub-terahertz applications. The focus of the present study is the simultaneous enhancement in current drivability as well as the reduction in parasitic capacitances without any trade-off, to achieve superior performance for sub-terahertz applications. Along with the analog characteristics of the proposed device, various critical high-frequency figures of merit have also been evaluated. Furthermore, scattering parameters have also been studied with variations in frequency to gain insights into the performance of the proposed device at high frequencies. In addition, a thorough comparison of the proposed device with the conventional device has been carried out. It has been demonstrated that the proposed device is an excellent contender for ultra-high-frequency applications with remarkable high-frequency figures of merit.
On-demand fabrication of piezoelectric sensors for in-space structural health monitoring
Authors: White Amanda , Little Isaac , Artyuk Anastasiya , McKibben Nicholas , Rajabi Kouchi Fereshteh , Chen Claire , Estrada David , Deng Zhangxian 
Published: April 2024

Abstract
Inflatable structures, promising for future deep space exploration missions, are vulnerable to damage from micrometeoroid and orbital debris impacts. Polyvinylidene fluoride-trifluoroethylene (PVDF-trFE) is a flexible, biocompatible, and chemical-resistant material capable of detecting impact forces due to its piezoelectric properties. This study used a state-of-the-art material extrusion system that has been validated for in-space manufacturing, to facilitate fast-prototyping of consistent and uniform PVDF-trFE films. By systematically investigating ink synthesis, printer settings, and post-processing conditions, this research established a comprehensive understanding of the process-structure-property relationship of printed PVDF-trFE. Consequently, this study consistently achieved the printing of PVDF-trFE films with a thickness of around 40 µm, accompanied by an impressive piezoelectric coefficient of up to 25 pC N−1. Additionally, an all-printed dynamic force sensor, featuring a sensitivity of 1.18 V N−1, was produced by mix printing commercial electrically-conductive silver inks with the customized PVDF-trFE inks. This pioneering on-demand fabrication technique for PVDF-trFE films empowers future astronauts to design and manufacture piezoelectric sensors while in space, thereby significantly enhancing the affordability and sustainability of deep space exploration missions.
Structural seismic response reconstruction method based on multidomain feature-guided generative adversarial neural networks
Authors: Liu Bo , Xu Qiang , Chen Jianyun , Ye Ming , Wang Mingming 
Published: April 2024

Abstract
Structural seismic response reconstruction is important to assess the safety of structures. This study presents a novel multidomain feature-guided generative adversarial neural network model (MWGAN-TF) for reconstructing the seismic responses of structures, which takes into account the joint non-stationarity of the seismic response in the time-frequency statistical domain. It innovatively incorporates time, frequency, and statistical-domain feature constraints into the multiscale generative adversarial neural network, which guides the model to learn the multidomain feature information of the seismic response at different time scales. A statistical indicator (CNCSI) was proposed to evaluate the performance of the model in capturing nonstationary characteristics. The effectiveness of the MWGAN-TF was verified using response data from numerical models of a three-story moment-resisting frame and reinforced concrete frame structures, as well as the field measurement data of an actual building. Thereafter, the effects of different domain feature-guided models on the reconstruction response accuracy are discussed. The results show that embedding multidomain feature constraints can provide a more reliable response reconstruction by improving the ability of the model to capture nonstationary characteristics. Thus, the deep learning paradigm based on multidomain feature guidance outperforms the classical neural network guided only by time-domain features.
Vortex in superconducting thin-film strips of arbitrary width
Authors: Nakagawa Norio , Kogan Vladimir G 
Published: April 2024

Abstract
The currents and field distributions of a vortex in a thin superconducting strip of a width W are considered. It is shown that unlike infinite films where the vortex field crosses the film only in one direction (say, from the half-space under the film to the half-space above it), in strips (as well as in finite size film samples of any shape) the field lines go back to the lower half-space not only out of the sample but also through certain strip parts. The strip patches where the magnetic lines ‘dive’ back to the space under the strip are situated mostly near the strip edges, at the strip and out of it. The magnetic flux through the strip associated with the vortex is shown to be less than the flux quantum and depends on the vortex position. The suppression of the vortex flux is strong in narrow strips with

W
<<
Λ
=
2

λ
2

/

d

where λ is the bulk London penetration depth and d is the film thickness. The vortex energy scales roughly with

W

/

Λ

and depends on vortex position.
Nonlinear optical properties of tunable spherical quantum dots under like-screened Kratzer potential
Authors: Wang Xing , Li Xuechao , Cai Yawen , Yan Xiaolong 
Published: April 2024

Abstract
Using the effective mass approximation and the iterative procedure, we study the optical rectification (OR) coefficient of a spherical quantum dot (QD) system with like-screened Kratzer potential (LSKP), taking into account the influence of the confinement potential depth, quantum size and external environment. Our results show that the magnitude of the OR coefficient is strongly dependent on the magnitude of the tunable factor, whose peak value will be red-shifted or blue-shifted. Interestingly, the limiting potential depth and temperature have opposite effects on the OR coefficient in terms of peak location and size. Therefore, it is necessary to pay more attention to the influence of internal and external parameters on nonlinear optical effects, and apply the theory to practical experiments and the manufacture of optoelectronic devices.
Robust digital image watermarking scheme with a fractional-order discrete-time chaotic scheme and DWT-SVD transform
Authors: Hannoun Katia , Hamiche Hamid , Lahdir Mourad , Megherbi Ouerdia , Laghrouche Mourad , Bettayeb Maamar 
Published: April 2024

Abstract
A robust digital image watermarking system with a fractional-order discrete-time chaotic system and discrete wavelet transform-singular value decomposition is presented. The inclusion method inserts an encrypted image into the dynamics of an integer-order discrete-time chaotic system and the resulting cipher serves as a host image watermark. A watermarking function (DWT-SVD transform) watermarks a host image before the watermark is extracted and decrypted at the receiver. As a contribution, our suggested approach introduces a new watermarking system based on discrete-time chaotic systems, as well as a hybridization of integer and fractional-order systems to ensure the watermarking scheme’s robustness. Our method achieved good results in terms of robustness, with normalized cross correlation values above 0.99 when subjected to a range of attacks. Results of the simulation underline practicality and robustness achieved by this approach. They also indicate that the proposed system resists various attacks.
Towards galaxy cluster models in Aether-Scalar-Tensor theory: isothermal spheres and curiosities
Authors: Durakovic A. , Skordis C. 
Published: April 2024

Abstract
The Aether-Scalar-Tensor (AeST) theory is an extension of General Relativity (GR) which can support Modified Newtonian Dynamics (MOND) behaviour in its static
weak-field limit, and cosmological evolution resembling ΛCDM.
We consider static spherically symmetric weak-field solutions in this theory and show that the resulting equations can be reduced to a single equation for the gravitational potential.
The reduced equation has apparent isolated singularities at the zeros of the derivative of the potential and we show how these are removed
by evolving, instead, the canonical momentum of the corresponding Hamiltonian system that we find. We construct solutions in three cases: (i) in vacuum outside a bounded spherical object, (ii) within an extended prescribed source, and (iii) for an isothermal gas in hydrostatic equilibrium, serving as a simplified model for galaxy clusters.
We show that the oscillatory regime that follows the Newtonian and MOND regimes, obtained in previous works in the vacuum case, also persists for isothermal spheres, and we show that the gas density profiles in AeST can become more compressed than their Newtonian or MOND counterparts.
We construct the Radial Acceleration Relation (RAR) in AeST for isothermal spheres and find that it can display a peak, an enhancement with respect to the MOND RAR, at an acceleration range determined by the value of the AeST weak-field mass parameter, the mass of the system and the boundary value of the gravitational potential. For lower accelerations, the AeST RAR drops below the MOND expectation,
as if there is a negative mass density. Similar observational features of the galaxy cluster RAR have been reported. This illustrates the potential of AeST to address the shortcomings of MOND in galaxy clusters, but a full quantitative comparison with observations will require going beyond the isothermal case.
Microscopic ensemble bootstrap in phase space
Authors: Zhang Yu 
Published: April 2024

Abstract
The bootstrap method which has been studied under many quantum mechanical models turns out to be feasible in microcanonical ensembles as well. While the approach of Nakayama (2022 Mod. Phys. Lett. A 37 2250054) produces a sector when energy is negative, in this paper we report a method that has stronger constraints and results in a smaller region. We also study other models to demonstrate the effectiveness of our method.