bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-dimensional chalcogenide-based ferromagnetic semiconductors
Authors: Wu Yanling , Li Jun , Liu Yong 
Published: December 2022

Abstract
Two-dimensional (2D) magnetic materials draw an enormous amount of attention due to their novel physical properties and potential spintronics device applications. Room-temperature ferromagnetic (FM) semiconductors have long been pursued in 2D magnetic materials, which show a long range magnetic order down to atomic-layer thickness. The intrinsic ferromagnetism has been predicted in a series of 2D materials and verified in experiments and the magnetism can be modulated by multiple physical fields, exhibiting promising application prospects. In this review, we overview several types of 2D chalcogenide-based FM semiconductors discovered in recent years. We summary and compare their basic physical properties, including the crystal structures, electronic structures, and mechanical stability. The 2D magnetism can be described by several physical models. We also focus on the recent progresses about theoretical prediction of FM semiconductors and experimental observation of external-field regulation. Most of investigations have shown that 2D chalcogenide-based FM semiconductors have relatively high Curie temperature (T

c

) and structural stability. These materials are promising to realize the room-temperature ferromagnetism in atomic-layer thickness, which is significant to design spintronics devices.
Terahertz magnetic excitation in antiferromagnets: atomistic spin simulations versus a coupled pendulum model
Authors: Zheng Cuixiu , Chen Xing , Zhou Sai , Liu Yaowen 
Published: December 2022

Abstract
Understanding and manipulating of the antiferromagnetic (AF) ultrafast spin dynamics in antiferromagnets (AFMs) is a crucial importance issue because of the promising applications in terahertz spintronic devices. In this study, an analytical theory extended from the classic coupled pendulum model has been developed to describe the intrinsic magnetic excitation of AFMs. The derived frequency dispersion of the AF resonances has been further checked by using the atomistic-level Landau–Lifshitz–Gilbert simulations. We show that the rutile crystalline AFM MnF2 possess two separate resonance modes at low magnetic fields: high frequency mode with right-handed polarization and low frequency mode with left-handed polarization. In the absence of magnetic field, these two resonance modes could degenerate into a single resonance state. When the applied magnetic field is higher than the spin-flip field, the system behaves a quasi-ferromagnetic mode. Both quantitative and qualitative agreement with atomistic simulation results confirm the theoretical picture of the AF resonance dynamics. This study provides a simple but physical understanding of the ultrafast dynamics of AF excitations.
On a fluid–structure interaction problem for plaque growth
Authors: Abels Helmut , Liu Yadong 
Published: December 2022

Abstract
We study a free-boundary fluid–structure interaction problem with growth, which arises from the plaque formation in blood vessels. The fluid is described by the incompressible Navier–Stokes equations, while the structure is considered as a viscoelastic incompressible neo-Hookean material. Moreover, the growth due to the biochemical process is taken into account. Applying the maximal regularity theory to a linearization of the equations, along with a deformation mapping, we prove the well-posedness of the full nonlinear problem via the contraction mapping principle.
Active vector models generalising 3D Euler and electron–MHD equations
Authors: Chae Dongho , Jeong In-Jee 
Published: December 2022

Abstract
We introduce an active vector system, which generalises both the 3D Euler equations and the electron–magnetohydrodynamic equations (E–MHD). We may as well view the system as singularised systems for the 3D Euler equations, in which case the equations of (E–MHD) correspond to the order two more singular one than the 3D Euler equations. The generalised surface quasi-geostrophic equation (gSQG) can be also embedded into a special case of our system when the unknown functions are constant in one coordinate direction. We investigate some basic properties of this system as well as the conservation laws. In the case when the system corresponds up to order one more singular than the 3D Euler equations, we prove local well-posedness in the standard Sobolev spaces. The proof crucially depends on a sharp commutator estimate similar to the one used for (gSQG) in Chae et al (2012 Commun. Pure Appl. Math.
65 1037–66). Since the system covers many areas of both physically and mathematically interesting cases, one can expect that there are various related problems to be investigated, parts of which are discussed here.
Exploring students’ perceptions of learning equilibrium concepts through making Bulan kites
Authors: Anantanukulwong Roseleena , Pongsophon Pongprapan , Chiangga Surasak , Tan Aik-Ling 
Published: December 2022

Abstract
This study reports students’ perceptions of learning the physics concepts of equilibrium through making Bulan kites. The Bulan kite encompasses indigenous knowledge related to the teachings and ideas found in Islam. After a workshop where students (n = 109) made the Bulan kite under the tutelage of a local expert, students (n = 12) were interviewed to distil their thoughts of the learning experience and their understanding of the concepts. The interviews were transcribed and content analysis was carried out. The findings indicate that students were able to make connections between the ideas of equilibrium and the art of kite construction which is based on indigenous knowledge. The kite making process also presented students with opportunities to be more aware of the value of local indigenous knowledge and motivated them in physics learning. We also discussed how indigenous knowledge can be incorporated meaningfully into physics learning.
A climbers pendulum fall
Authors: O’Shea Michael J 
Published: December 2022

Abstract
We analyse a lead climber pendulum fall, a fall that can occur after the climber traverses horizontally away from their highest anchor. The model is based on a spring pendulum with a nonlinear component and incorporates air resistance. The resulting set of equations can be solved numerically using an Excel spreadsheet that is easily implemented by a student. The maximum tension and speed during the fall were calculated for a real dynamic climbing rope. The inclusion of rope elasticity can, under the right conditions, lead to a speed at the bottom of the swing that is less than that found for a stiff rope. The path of the climber is not closed as they swing back and forth, and we analyse radial oscillations to gain further insight. For multiple swings, the air resistance is important for removing energy from the system.
Wireless at its origin
Authors: Riccardi P , Prete G , Chiappetta F , Meringolo C 
Published: December 2022

Abstract
This work discusses a didactic path aimed at revisiting the first experiments on the transmission and detection of electromagnetic waves, performed by Guglielmo Marconi at the end of the 19th century. With very simple materials it is possible to set-up apparatus that allow to illustrate practically the simple physical picture of wireless telegraphy, and in particular the role of monopole antennas and ground connections, first introduced by Guglielmo Marconi to increase the distance between the transmitter and the receiver. Retracing in the classroom the first steps of the beginning and the advent of radio communications is important for both science education and the students’ understanding of the connected world we live in.
Fast 3D kernel computation method for positron range correction in PET
Authors: Li Chong , Scheins Jürgen , Tellmann Lutz , Issa Ahlam , Wei Long , Shah N Jon , Lerche Christoph 
Published: December 2022

Abstract

Objective. The positron range is a fundamental, detector-independent physical limitation to spatial resolution in positron emission tomography (PET) as it causes a significant blurring of underlying activity distribution in the reconstructed images. A major challenge for positron range correction methods is to provide accurate range kernels that inherently incorporate the generally inhomogeneous stopping power, especially at tissue boundaries. In this work, we propose a novel approach to generate accurate three-dimensional (3D) blurring kernels both in homogenous and heterogeneous media to improve PET spatial resolution. Approach. In the proposed approach, positron energy deposition was approximately tracked along straight paths, depending on the positron stopping power of the underlying material. The positron stopping power was derived from the attenuation coefficient of 511 keV gamma photons according to the available PET attenuation maps. Thus, the history of energy deposition is taken into account within the range of kernels. Special emphasis was placed on facilitating the very fast computation of the positron annihilation probability in each voxel. Results. Positron path distributions of 18F in low-density polyurethane were in high agreement with Geant4 simulation at an annihilation probability larger than 10−2 ∼ 10−3 of the maximum annihilation probability. The Geant4 simulation was further validated with measured 18F depth profiles in these polyurethane phantoms. The tissue boundary of water with cortical bone and lung was correctly modeled. Residual artifacts from the numerical computations were in the range of 1%. The calculated annihilation probability in voxels shows an overall difference of less than 20% compared to the Geant4 simulation. Significance. The proposed method is expected to significantly improve spatial resolution for non-standard isotopes by providing sufficiently accurate range kernels, even in the case of significant tissue inhomogeneities.
Evaluation of raw segmental bioelectrical impedance variables throughout anterior cruciate ligament reconstruction rehabilitation
Authors: Cleary Christopher J , Weir Joseph P , Vopat Bryan G , Herda Ashley A 
Published: December 2022

Abstract

Background. Raw bioelectrical impedance analysis (BIA) variables are related to physical function in healthy and diseased populations. Therefore, BIA may be an insightful, noninvasive method of assessment to track following anterior cruciate ligament reconstruction (ACLR). Objectives. Evaluate phase angle, reactance and impedance at 50 kHz (PhA50, Xc50, and Z
50, respectively) in the operative (OP) and non-operative (NOP) limbs during ACLR rehabilitation. Approach. Seventeen patient (12 M, 5 F; 18.8 ± 4.8 years) clinic reports were evaluated prior to ACLR (PRE), two- (2 W), six- (6 W), and twelve-weeks (12 W) post-ACLR and at return to sport testing (RTS). Setting. All observations occurred during the participant’s physical therapy visits. Measurements. A multi-frequency BIA device measured segmental PhA, Xc, and Z. Linear mixed effects models were used to assess any leg and time interaction and changes over leg and time, independently. Any interactions or main effects were considered significant at p < 0.05. Main results. Significant leg x time interactions were observed for each variable. PhA50 and Xc50 of NOP were higher (p < 0.001) than OP at each time point by an average of by 0.9° and 4.9 Ω, respectively. In OP, PhA50 and Xc50 decreased from PRE to 2 W and increased from 6 to 12 W and 12 W to RTS (p < 0.01, for all). At RTS, PhA50 and Xc50 were similar to PRE in OP (p > 0.05). For Z
50, the OP leg did not change over time (p > 0.05). Z
50 was greater in NOP at 2 and 6 W (p < 0.01, for both). There were differences in PhA50 in NOP between PRE and 6 W and from 6 W to RTS (p < 0.05 for both). Xc50 did not change (p > 0.05), and Z
50 PRE was lower than at 2 W (p < 0.05). Significance. A multi-frequency BIA device can detect changes in segmental BIA variables following ACLR.
Investigation of the synergistic effects of ICRF + NBI heating in EAST plasma discharges
Authors: Song Chengyi , Wu Bin , Gong Xueyu , Wang Ji , Chen Yuqing , Hao Baolong , Ti Ang , Wang Shouxin , He Liang , Zhong Guoqiang , Yin Lan , Li Jun , Cui Zhiwei , Huang Qianhong , Zhong Yijun , Xie Yahong , Xie Yuanlai 
Published: December 2022

Abstract
Following an upgrade of the neutral beam injection (NBI) system, obvious synergy between combined NBI and ion cyclotron resonance frequency (ICRF) heating was observed in recent experiments conducted at EAST. To investigate the effects of beam-ions accelerated by radiofrequency (RF) wave, analyses are performed by using TRANSP code based on the experimental results. The calculated results argue that only a small fraction of the ICRF power is absorbed by the beam ions in the ICRF + NBI synergistic heating of the (H)D plasma. To enhance the beam–RF interactions in synergistic heating and achieve high plasma performance of EAST, different experimental conditions, including multiple injection powers and diverse beam injection options, were explored. Beam injected fast ions are passing particles, trapped particles observed when synergy heating between ICRF and NBI. In particular, by varying the injection direction of the beam ions it was observed that more tangential beam yields better synergy in comparison with more perpendicular beam. The neutron emission rate of D–D fusion in tokamaks is improved and less fast ion loss is produced with tangential NBI + ICRF heating. Also, the effect of the ratio P
ICRF/P
NBI on ICRF + NBI combined heating is demonstrated, the higher power boosts the fusion enhancement. The study of the performed synergistic heating provides an important reference for the subsequent combined NBI + ICRF heating experiments on EAST.
2D-imaging of absolute OH and H2O2 profiles in a He–H2O nanosecond pulsed dielectric barrier discharge by photo-fragmentation laser-induced fluorescence
Authors: van den Bekerom Dirk , Tahiyat Malik M , Huang Erxiong , Frank Jonathan H , Farouk Tanvir I 
Published: December 2022

Abstract
Pulsed dielectric barrier discharges (DBD) in He–H2O and He–H2O–O2 mixtures are studied in near atmospheric conditions using temporally and spatially resolved quantitative 2D imaging of the hydroxyl radical (OH) and hydrogen peroxide (H2O2). The primary goal was to detect and quantify the production of these strongly oxidative species in water-laden helium discharges in a DBD jet configuration, which is of interest for biomedical applications such as disinfection of surfaces and treatment of biological samples. Hydroxyl profiles are obtained by laser-induced fluorescence (LIF) measurements using 282 nm laser excitation. Hydrogen peroxide profiles are measured by photo-fragmentation LIF (PF-LIF), which involves photo-dissociating H2O2 into OH with a 212.8 nm laser sheet and detecting the OH fragments by LIF. The H2O2 profiles are calibrated by measuring PF-LIF profiles in a reference mixture of He seeded with a known amount of H2O2. OH profiles are calibrated by measuring OH-radical decay times and comparing these with predictions from a chemical kinetics model. Two different burst discharge modes with five and ten pulses per burst are studied, both with a burst repetition rate of 50 Hz. In both cases, dynamics of OH and H2O2 distributions in the afterglow of the discharge are investigated. Gas temperatures determined from the OH-LIF spectra indicate that gas heating due to the plasma is insignificant. The addition of 5% O2 in the He admixture decreases the OH densities and increases the H2O2 densities. The increased coupled energy in the ten-pulse discharge increases OH and H2O2 mole fractions, except for the H2O2 in the He–H2O–O2 mixture which is relatively insensitive to the additional pulses.
Sterilization of Salmonella typhimurium and Staphylococcus aureus in different cold-chain environments by combining NO
x
mode and O3 mode air discharges
Authors: Chen Min , Yan Jinwei , Feng Yue , Liu Dingxin , Wang Zifeng , Liu Linbo , Huang Lingling , Guo Li , Zhang Jingyao , Liu Chang , Rong Mingzhe 
Published: December 2022

Abstract
Cold-chain transport has been suggested to be an important means for the cross-regional transmission of pathogenic microorganisms. In this study, NO
x
mode and O3 mode air discharges were combined by mixing effluent gases for sterilization in several cold-chain environments. It was found that the mixed gas effectively inactivated Salmonella typhimurium and Staphylococcus aureus in 1–4 mm thick ice layers at different temperatures (−20/−40/−80 °C) within 10 min, which is a significantly stronger effect than that of the effluent gas of either the NO
x
mode or the O3 mode discharge alone. This can be attributed to the high-valence reactive nitrogen species such as N2O5. Our findings provide a promising sterilization strategy to curb the spread of infectious diseases in cold-chain environments.
Simultaneous determination of source term and the initial value in the space-fractional diffusion problem by a novel modified quasi-reversibility regularization method
Authors: Wen Jin , Ren Xue-Juan , Wang Shi-Juan 
Published: December 2022

Abstract
This paper deals with an inverse problem of determining source term and initial data simultaneously for a space-fractional diffusion equation in a strip domain, with the aid of extra measurement data at a fixed time. The uniqueness results are obtained by a simple trick based on the linear property of the proposed equation. Since this problem is ill-posed, a modified quasi-reversibility method is obtained by employing the Fourier transform. Error estimates for source term and initial value are obtained from a suitable parameter choice rule. Finally, several numerical examples show that the proposed regularization method is effective and stable.
Experimental investigation on the impacting and freezing characteristics of water droplets on a PDMS-decorated superhydrophobic aluminum alloy surface
Authors: Peng Huaqiao , Shi Tao , Yang Hanming , Liu Yourui , Wang Qiang , Su Zhengliang , Xia Zuxi 
Published: December 2022

Abstract
Due to the potential applications of superhydrophobic surfaces in water-repelling and anti-icing, it is of great interest to study the impacting and freezing processes of water droplets on superhydrophobic surfaces. In this study, the process of a water droplet impacting the PDMS-decorated superhydrophobic aluminum alloy (denoted as Al-PDMS) surface was studied, and the influences of a water droplet falling height and volume were systemically investigated with a high-speed camera. The results indicate that the impacting process can be categorized into four states, which are mainly affected by the dropping height. The bouncing processes of water droplets on horizontal superhydrophobic surfaces are studied by defining spreading factor α and rebounding factor β. Furthermore, the effect of the inclination angle φ of the superhydrophobic plate on the impacting behavior was investigated. The freezing processes of water droplets on superhydrophobic surfaces were also studied. The results showed that the delayed-icing time decreases with decreasing test plate temperature. Additionally, the volume and height of the frozen portion of the water droplets during freezing were investigated, and the movement characteristic of the freezing front was analyzed.
Giant and strain-tunable interfacial magnetic anisotropy in MgO-based magnetic heterostructures with heavy atoms insertion
Authors: Hu Yue , Yan Shiming , Jin Deyou , Qiao Wen , Bai Ru , Zhou Tiejun 
Published: December 2022

Abstract
MgO-based magnetic heterostructures with interfacial magnetic anisotropy has attracted increasing attention due to its application in building high-density magnetic random access memories. A large and tunable interfacial magnetic anisotropy constant (Ki) is required for high thermal stability and flexible data writability. In this study, the Ki of Fe/MgO, Fe/Pt/MgO, and Fe/Ir/MgO heterostructures with strains from −4.5% to 4.5% were calculated by ab initio electronic structure calculations. It has been found that the Fe/Pt/MgO and Fe/Ir/MgO where the Pt and Ir monolayers are inserted in the interface possess Ki of 2.415 mJ m−2 and −4.468 mJ m−2, which are much larger by several times than that (0.840 mJ m−2) of the Fe/MgO. In particular, the out-of-plane Ki from the interfacial Pt atoms in Fe/Pt/MgO is as high as 5.978 mJ m−2. The magnetic anisotropy of these structures can be significantly manipulated by strain. Combining second-order perturbation theory, the origin of these behaviors has been analyzed by layer-resolved, orbital-resolved, and k-resolved Ki. The spin-flip terms of d

z
2/d

yz
orbitals in the interfacial layer are mainly responsible for the out-of-plane Ki and its variation with strain. This work provides a useful guide for the design of high and tunable magnetic anisotropy in the MgO-based magnetic heterostructures.
Testing Lorentz invariance of gravity in the Standard-Model Extension with GWTC-3
Authors: Niu Rui , Zhu Tao , Zhao Wen 
Published: December 2022

Abstract
Successful detection of gravitational waves has presented a new avenue to explore the nature of gravity. With the cumulative catalog of detected events, we can perform tests on General Relativity from various aspects with increasing precision.
In this work, we focus on Lorentz symmetry during propagation of gravitational waves.
Considering the dispersion relation in the gauge-invariant linearized gravity sector of the Standard-Model Extension, the anisotropy, birefringence, and dispersion effects will be induced during propagation of gravitational waves because of the Lorentz violating modification, and cause dephasings in waveform received by detectors.
With the distorted waveform, we perform full Bayesian inference with confident events in the last gravitational wave catalog. We consider two cases associated with the lowest mass dimension d = 5,6 which are supposed to have the most significant effects, and place the constraints on the expansion coefficients characterizing the Lorentz violating behavior which have 16 independent components for d = 5 and 18 components for d = 6.
We do not find any evidence for Lorentz violation in the gravitational wave data, the constraints on the coefficients are on the order of 10-15 m for d = 5 and 10-10 m2 for d = 6 respectively.
Expected measurement precision of the branching ratio of the Higgs boson decaying to the di-photon at the CEPC*
Authors: Guo Fangyi , Fang Yaquan , Li Gang , Lou Xinchou 
Published: December 2022

Abstract
This paper presents the prospects of measuring

in three Z decay channels

using the baseline detector with

GeV at the Circular Electron Positron Collider (CEPC). Simulated Monte Carlo events were generated and scaled to an integrated luminosity of 5.6 ab–1 to mimic the data. Extrapolated results to 20 ab–1 are also reported. The expected statistical precision of these measurements after combining three channels of Z boson decay was 7.7%. With some preliminary estimation on the systematical uncertainties, the total precision is 7.9%. The performance of the CEPC electro-magnetic calorimeter (ECAL) was studied by smearing the photon energy resolution in simulated events in the

channel. In the present ECAL design, the stochastic term in resolution plays the dominant role in the precision of Higgs measurements in the

channel. The impact of the resolution on the measured precision of

as well as the optimization of the ECAL constant and stochastic terms were studied for further detector design.