bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homogenization and short-range chemical ordering of Co–Pt alloys driven by the grain boundary migration mechanism
Authors: Pedan Roman , Makushko Pavlo , Dubikovskyi Oleksandr , Bodnaruk Andrii , Burmak Andrii , Sidorenko Sergiy , Voloshko Svitlana , Kalita Viktor , Hübner René , Makarov Denys , Vladymyrskyi Igor 
Published: July 2022

Abstract
Binary magnetic alloys like Co–Pt are relevant for applications as components of magnetic exchange coupled composites. Numerous approaches exist to tune the coercive field of Co–Pt alloys primarily relying on high-temperature processing aiming to realize chemically long-range ordered phases. The peculiarity of Co–Pt is that large coercive field and magnetic anisotropy can be achieved even in chemically disordered alloys relying on short-range order. Here, we study alloying of Co–Pt from bilayers of Pt(14 nm)/Co(13 nm) at temperatures up to 550 °С, where bulk diffusion processes are suppressed and the dominant diffusion mechanism is grain boundary migration. We demonstrate that grain boundary diffusion mechanism can lead to the realization of a homogeneous yet chemically disordered Co56Pt44 alloy at temperatures of 500 °С and higher. A pronounced increase of the coercive field for samples processed at temperatures higher than 400 °С is attributed to short-range ordering. With this work, we pinpoint the grain boundary diffusion as the mechanism responsible not only for the homogenization of binary alloy films but also as a driving force for the realization of short-range order in Co–Pt. Our results motivate further research on grain boundary diffusion as a mechanism to realize chemically long-range ordered phases in Co–Pt alloys.
Bandpass filters using grounded stub-loaded microstrip periodic structure for suppression of modes
Authors: Liu Yiqun , Xu Kai-Da 
Published: July 2022

Abstract
In this paper, a grounded stub-loaded microstrip periodic structure (SL-MPS) is presented and its transmission characteristics are investigated. A new method of suppression of modes is proposed through adding grounded via holes on the grounded SL-MPS for the design of bandpass filters (BPFs). In order to validate the feasibility of suppression of modes of grounded SL-MPS, two cases of BPFs with different dimensions are designed. For the case of BPF with suppression of adjacent modes, the simulated and measured results of BPFs demonstrate that the fundamental and 2nd high-order modes can be effectively suppressed. For the other case of BPF with suppression of multiple modes, the fundamental, 1st, 3rd and 4th high-order modes can be successfully suppressed. The measurements of these BPFs are reasonably in agreement with their simulations. Observed from the theoretical analysis and experimental results, the proposed method can effectively widen the stopband of BPF by suppressing unwanted modes.
Absorption-transmission-type multifunctional coding metasurface
Authors: Chen Jiayu , Li Weihan , Zhang Yunfeng , Ma Wenyu , Tang Wenxuan , Cui Tiejun 
Published: July 2022

Abstract
Reflection- and transmission-type metasurfaces have great potentials in wireless communications. In this letter, we propose an absorption-transmission-type multifunctional coding metasurface composed of an absorptive layer and a transmissive layer. For incident waves at different frequencies with different polarizations, the proposed coding metasurface can perform three different functions independently: wave absorption at low frequencies, vortex-wave generation for the x-polarized wave and beam deflection for the y-polarized wave at high frequencies. Both numerical and experimental results verify the excellent performance of low-frequency absorptions and high-frequency dual-polarization transmissions. This work provides a method for developing multifunctional and reconfigurable components for the wireless communications in the future.
Reading the lattice QCD form factors of the Λ
b
→ Λ
c
transition using a C-code
Authors: Smith Bradley , Rashed Ahmed , Huo Chen 
Published: July 2022

Abstract
The

Λ

b

→

Λ

c

ℓ

−

ν

¯

ℓ

process has been discussed in the literatures as a probe for new physics. This process receives contributions in new physics models from scalar, vector, and tensor hadronic currents. The form factors of these currents can be obtained from the quark model or the lattice QCD. In this work, we present a c-code to read the scalar, vector, and tensor lattice QCD form factors. The code is published on github (https://github.com/darkfiresmith96/Lattice_QCD). A Mathematica code was used in reference Datta et al (2017 J. High Energy Phys.
8 131) to read the form factors. Our c-code is much faster than the Mathematica code where the ratio of the wall clock time for the c-code compared to the Mathematica code is 1:64.2 per data point. A web interface for user inputs is introduced.
The skyrmion bags in an anisotropy gradient
Authors: Zeng Zhaozhuo , Mehmood Nasir , Ma Yunxu , Wang Jianing , Wang Jianbo , Liu Qingfang 
Published: July 2022

Abstract
Skyrmion bags as spin textures with arbitrary topological charge are expected to be the carriers in racetrack memory. Here, we theoretically and numerically investigated the dynamics of skyrmion bags in an anisotropy gradient. It is found that, without the boundary potential, the dynamics of skyrmion bags are dependent on the spin textures, and the velocity of skyrmionium with Q = 0 is faster than other skyrmion bags. However, when the skyrmion bags move along the boundary, the velocities of all skyrmion bags with different Q are same. In addition, we theoretically derived the dynamics of skyrmion bags in the two cases using the Thiele approach and discussed the scope of Thiele equation. Within a certain range, the simulation results are in good agreement with the analytically calculated results. Our findings provide an alternative way to manipulate the racetrack memory based on the skyrmion bags.
Assessment of occupational dose reduction with the use of a floor mounted mobile lead radiation protection shield
Authors: Scott Hannah , Gallagher Sean , Abbott William , Talboys Matthew 
Published: July 2022

Abstract
With the increasing number and complexity of interventional cardiology procedures, there is the potential for higher occupational radiation doses to the interventionists. In order to reduce the radiation exposure to interventionists, a number of different radiation protection measures can be implemented; the most common of which being personal protective equipment in the form of a lead-equivalent apron. However, significant development has been achieved with mobile lead equivalent radiation protection devices, which provide enhanced radiation protection without the requirement of being directly worn by staff. The RAMPART M1128 radiation protection shield is one of these devices. The dose reduction provided to staff within a Cardiac Catheterisation Laboratory was assessed via the use of electronic personal dosimeters with the Philips live dosimetry system DoseAware (Philips DoseAware). A 60% dose reduction to the primary operator can be achieved with the Rampart device. Further dose reductions are possible for other individuals in the range of 65%–84%. Additionally, dose rate measurements were taken in a simulated clinical set-up using a phantom, which showed that the device provided a 65% dose reduction at eye level and a 90% dose reduction at chest level for the primary operator position. This significant dose reduction means that there is the potential for at least the primary operator to wear a lead apron of reduced lead equivalence specification when the Rampart device is in use, without increasing their occupational exposure and potentially reducing musculoskeletal pain due to the reduced weight.
Weak fault diagnosis of machinery using Laplacian eigenmaps and parallel sparse filtering
Authors: Ji Shanshan , Wang Jinrui , Han Baokun , Zhang Zongzhen , Bao Huaiqian , An Yuxi , Zhang Ming , Wang Hualong 
Published: July 2022

Abstract
Machinery fault diagnosis is crucial for maintenance cost reduction and accident prevention. Vibration signal monitoring is an effective and feasible method for machinery fault diagnosis. However, extraction of the fault-related periodic impulses from weakly monitoring signals is basic but difficul . In this paper, a new weak feature extraction model using Laplacian eigenmaps and parallel sparse filtering (LE-PSF) is presented for mechanical weak fault diagnosis. Specifically, the weak vibration signal is measured from the machinery pedestal. Then, LE is used to extract principal components of the overlapped signal segments, and PSF is employed for weak feature extraction from the principal components. Finally, the extracted features are inputted to softmax regression for fault classification. A simulation study and two experimental cases are employed to testify the effect of the LE-PSF model. Experimental performances show that the LE-PSF can not only achieve accurate fault classification but also is superior to other traditional methods.
Image reconstruction using Z-axis spatio-temporal sampling in 3D electrical capacitance tomography
Authors: Wanta Damian , Smolik Waldemar T , Kryszyn Jacek , Midura Mateusz , Wróblewski Przemysław 
Published: July 2022

Abstract
Three-dimensional (3D) visualization has provoked interest in electrical capacitance tomography (ECT) due to recent progress in the development of capacitance measurement circuits and data-acquisition systems. This paper proposes image reconstruction using spatio-temporal sampling in the Z-axis for 3D ECT to improve spatial image resolution. In a typical application of ECT, multi-phase flow imaging is performed through two-dimensional (2D) data acquisition and 2D reconstruction of image frames over time. In the presented method, a volume of interest (VOI) is reconstructed from several time samples obtained using a 3D sensor. The procedure of Jacobian matrix extension for the spatio-temporal data is described. The experiments were carried out using the EVT4 system and a 32-electrode sensor. The reconstruction results of a VOI from a single 3D measurement and spatio-temporal sampling are compared. A phantom for 3D imaging to assess spatial image resolution using a modulation transfer function is proposed.
Heavy Mn-doped CsPbBr3 nanocrystals synthesized by high energy ball milling with high stability
Authors: Wang Lei , Mao Hengbin , Li Junhui , Li Yi , Li Mingliang , Zhu Jinpeng , Fan Bingbing , Liu Wen , Shao Gang , Xu Hongliang , Wang Hailong , Zhang Rui , Lu Hongxia 
Published: July 2022

Abstract
CsPbX3 (X = Cl, Br, I) semiconductor nanocrystals (NCs) have excellent optical and photoelectric properties, and are potential core materials for various photoelectric devices. However, the toxicity of Pb and instability have been the key limitations to application of NCs. Herein, using MnBr2 and MnBr2·4H2O as manganese sources, heavy Mn-doped CsPbBr3 (Mn:CsPbBr3) NCs are synthesized by high-energy ball grinding, which avoids high temperature, a large number of polar solvents and atmosphere protection required in traditional liquid phase methods. However, when MnBr2·4H2O is used as the raw material, infinite solid solution doping can be achieved, and the synthesized Mn:CsPbBr3 NCs show smaller particle size, stronger PL intensity and stability. The reason is that presence of crystal water plays a similar role to wet milling in the ball milling process, and can promote the passivation effect of oleylamine (OAm) on nanocrystal defects and the connection between them. In addition, a simple, easy-operating and beneficial to commercial production method for the preparation of Mn:CsPbBr3 NCs/EVA flexible films is proposed, which can effectively improve the stability of Mn:CsPbBr3 NCs. This study is expected to provide an effective way for the synthesis and stability improvement of CsPbX3 NCs doped with different ions.
Understanding the linear and nonlinear optical responses of few-layer exfoliated MoS2 and WS2 nanoflakes: experimental and simulation studies
Authors: Abhijith T , E Shiju , Suthar Rakesh , Sharma Punit , Thomas Sheenu , Karak Supravat 
Published: July 2022

Abstract
Understanding the linear and nonlinear optical (NLO) responses of two-dimensional nanomaterials is essential to effectively utilize them in various optoelectronic applications. Here, few-layer MoS2 and WS2 nanoflakes with lateral size less than 200 nm were prepared by liquid-phase exfoliation, and their linear and NLO responses were studied simultaneously using experimental measurements and theoretical simulations. Finite-difference time-domain (FDTD) simulations confirmed the redshift in the excitonic transitions when the thickness was increased above 10 nm indicating the layer-number dependent bandgap of nanoflakes. WS2 nanoflakes exhibited around 5 times higher absorption to scattering cross-section ratio than MoS2 nanoflakes at various wavelengths. Open aperture Z scan analysis of both the MoS2 and WS2 nanoflakes using 532 nm nanosecond laser pulses reveals strong nonlinear absorption activity with effective nonlinear absorption coefficient (β
eff) of 120 cm GW−1 and 180 cm GW−1, respectively, which was attributed to the combined contributions of ground, singlet excited and triplet excited state absorption. FDTD simulation results also showed the signature of strong absorption density of few layer nanoflakes which may be account for their excellent NLO characteristics. Optical limiting threshold values of MoS2 and WS2 nanoflakes were obtained as ∼1.96 J cm−2 and 0.88 J cm−2, respectively, which are better than many of the reported values. Intensity dependent switching from saturable absorption (SA) to reverse SA was also observed for MoS2 nanoflakes when the laser intensity increased from 0.14 to 0.27 GW cm−2. The present study provides valuable information to improve the selection of two-dimensional nanomaterials for the design of highly efficient linear and nonlinear optoelectronic devices.
Phase change and order 2 averaging for one-frequency systems with separatrix crossing*
Authors: Neishtadt Anatoly , Okunev Alexey 
Published: July 2022

Abstract
We study the evolution of angular variable (phase) for general (not necessarily Hamiltonian) perturbations of Hamiltonian systems with one degree of freedom near separatrices of the unperturbed system. To this end, we use the averaged system of order 2. We obtain estimates for the accuracy of the order 2 averaged system near separatrices and use these estimates to prove a formula for the phase change when solutions of the perturbed system approach separatrices of the unperturbed system (such formula is known when the perturbation is Hamiltonian). As an application of this formula, we show that two natural definitions of probability of capture into different domains after separatrix crossing proposed by Arnold and Anosov lead to the same formula for this probability.
Simulation study of a novel vertical GaN-based FS-IGBT
Authors: Wang Kai , Shangguan Shaofei , Zhang Peng , Liu Shuang , Li Mengdi , Ma Xiaohua , Hao Yue 
Published: July 2022

Abstract
In this paper, a novel GaN-based field stop-insulated gate bipolar transistor (FS-IGBT) is designed, which combines GaN-based Fin-MOS with the conventional material FS-IGBT, and the static and dynamic electrical characteristics of the device are simulated by Silvaco. The results show that the structure has a high saturation current (I
on,sat) density of 155 kA cm−2 at 10 V gate voltage (V
ge), an on-state voltage (V
on) of 3.5 V, a breakdown voltage (BV) of 1650 V, and a switching speed of nanoseconds. The characteristics of the device are analyzed and compared with Fin-MOS. The results demonstrate that the vertical GaN-based device can display both high current density and high BV due to the FS layer that adjusts the electric field distribution in the N-drift region. The paper also analyzes the selection of device parameters and feasibility of device manufacturing based on the existing material growth method and device manufacturing technology.
Resonant-type inertial impact linear piezoelectric motor based on coupling of driving and clamping parts
Authors: He Liangguo , Li Kun , Yan Yi , Wang Yong , Xiao Feiyun , Ge Xinfang , Gao Guangjie , Shan Zengxiang , Dou Haotian 
Published: July 2022

Abstract
A resonant-type inertial impact linear piezoelectric motor based on coupling of driving and clamping parts was designed and manufactured. The motor mainly includes stator (coupling of driving and clamping parts), mover (slider) and auxiliary parts. The driving part works in the resonant state under the excitation of single harmonic, which mainly realizes the function of reciprocating driving. Similarly, under the single harmonic driving, the clamping part also works in the resonant state to realize the clamping function. Through the coupling between the two parts of the stator, the mover is driven to move continuously in one direction. The inertial impact piezoelectric motor works in the resonant state because the driving and clamping parts work in the resonant state respectively. Compared with the traditional quasi-static inertial impact motor, this study novelly changes the working state of the inertial impact motor. Through the finite element simulation software COMSOL 5.2, the resonant frequency coupling of the driving and the clamping part is consistent. An experimental platform was built to verify the feasibility of the principle by testing the motor prototype. The experiment results show that: The maximum speed reaches 78 mm s−1 when the motor prototype is operated at the frequency of 810 Hz with a preload of 2 N and the working voltages of clamping and driving parts of motor were set at 80 and 220 Vp-p respectively. Meanwhile, the maximum load of the motor prototype can reach 5 N. The minimum resolution of the motor prototype is 6.379 μm.
Guided waves based damage localization based on mode filtering using fiber Bragg grating sensors
Authors: Soman Rohan , Radzienski Maciej , Kudela Pawel , Ostachowicz Wieslaw 
Published: July 2022

Abstract
Fiber Bragg grating (FBG) sensors have long been thought of as the ideal sensors for structural health monitoring (SHM) due to their small size, light weight, ability to be embedded and ability to be multiplexed. So, FBG sensors have been commonly used for strain based SHM. Their use for ultrasonic guided wave (GW) measurements in the traditional wavelength division multiplexing approach was tried as well, but did not get accepted widely due to the low sensitivity. In the recent times, a renewed interest is seen in the use of FBG sensors for GW measurements using the edge reflection approach which increases the sensitivity several folds. This paper reports a very interesting phenomena, shown by the FBG sensors. The mechanism of the measurement of the incident GW is different based on the relative ratio of the wavelength of the incident GW (

λ

G
W

) and the grating length (L) of the FBG sensor. For

λ

G
W

/

L
≫

1 the propagating wave leads to uniform strain over the FBG resulting in the shift of the Bragg wavelength. For the

λ

G
W

/

L
≈

1 the FBG experiences non-uniform strain over the FBG which results in the distortion of the spectrum (widening or narrowing) of the peak. By separating these effects on the FBG, mode filtering may be achieved. The mode-filtered data is then used for damage detection and damage localization. Modifications have been proposed to the elliptical approach which makes use of the filtered modes and removes the unwanted peaks in the signal stemming from the other mode. The methodology is validated on a simple aluminum plate with simulated damage scenarios (added mass). The results indicate that indeed the mode-filtered signals improve the damage localization performance of the actuator-sensor network.
Multi-GeV cascaded laser wakefield acceleration in a hybrid capillary discharge waveguide
Authors: Qin Zhiyong , Li Wentao , Liu Jiaqi , Liu Jiansheng , Wang Wentao , Yu Changhai , Zhang Zhijun , Wang Xinliang , Li Jinfeng , Leng Yuxin , Liang Xiaoyan , Li Ruxin , Xu Zhizhan 
Published: July 2022

Abstract
Based on a 6 cm-long two-segment hybrid capillary discharge waveguide, a multi-GeV electron beam with energy up to 3.2 GeV and 9.7% rms energy spread was achieved in a cascaded laser wakefield acceleration scheme, powered by an on-target 210 TW laser pulse. The electron beam was trapped in the first segment via ionization-induced injection, and then seeded into the second segment for further acceleration. The long-distance stable guiding of the laser pulse and suppression of the dark current inside the second-segment capillary played an important role in the generation of high-energy electron beams, as demonstrated by quasi-three-dimensional particle-in-cell simulations.
Coherent control of extreme ultraviolet emission generated through frustrated tunneling ionization
Authors: Kim Yang Hwan , Yun Hyeok , Hwang Sung In , Ivanov Igor A , Nam Chang Hee , Kim Kyung Taec 
Published: July 2022

Abstract
Coherent extreme ultraviolet (EUV) line emissions can be generated from an atom excited through frustrated tunneling ionization (FTI). The phase variation of the EUV emission in a generation medium along the propagation direction is a critical parameter that determines the phase-matching condition of this new light source. Here we show that the EUV emission sensitively depends on the intensity and phase of a driving laser pulse and the target position. Angle-resolved EUV spectra measured at different target positions and the carrier-envelope phases of the laser pulse exhibit an intensity modulation, showing similar behavior to that of a long-trajectory high harmonic radiation. The four-step model developed for the FTI emission accurately describes the coherent control of the EUV emission. These findings are essential ingredients for developing coherent extreme ultraviolet sources with high photon flux and for utilizing the FTI emission in time-resolved spectroscopy.
A scenario for high-temperature excitonic insulators
Authors: Yang Huaiyuan , Wang Xinqiang , Li Xin-Zheng 
Published: July 2022

Abstract
While excitonic insulators (EIs) have been intensively studied, proper platforms of them with stable lattice and non-cryogenic T
C are rare. By analysing their Bardeen–Cooper–Schieffer-like gap equation, we propose that high T
C EIs can exist in small indirect band gap 2D materials. After screening 2D transition-metal dichalcogenides from existing computational works, we select 2H-TiTe2 and 1T-PdTe2, and show that their T
C can be as high as 150 to 200 K under strains. A transition of their condensate EI state from that composed by Wannier excitons to that composed by plasmonic ones exists, even if negligible changes are reflected by the EI band structures, demonstrating the rich quantum feature of these systems. The high T
C also implies that they are ideal platforms for the demonstration and applications of EIs and their related quantum states in non-cryogenic environments.
Observational constraints on the massive neutrinos induced late-time cosmic acceleration
Authors: Sharma Mohit K , Pacif Shibesh Kumar Jas , Myrzakul Shynaray , Shanina Zamzagul 
Published: July 2022

Abstract
We investigate a late-time cosmological scenario at the both cosmological background and linear perturbative level which is based on a mass-less λ
ϕ
4 theory in which the scalar field is inextricably coupled to massive neutrino matter with Z
2 symmetry by a well defined conformal coupling. The chosen coupling generically leads to the spontaneous symmetry breaking at late times, as the coupling builds up dynamically, such that the field acquires a non-zero mass proportional to the neutrino mass and rolls down slowly around the true ground state which emerges after spontaneous symmetry breaking. From our parametric estimations, we find the given scenario is well supported by the background level cosmological observations and is also in a good agreement with the evolution of growth of matter perturbations.