bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced thermoelectric properties of polycrystalline CuCrS2−x
Se
x
(x = 0, 0.5, 1.0, 1.5, 2) samples by replacing chalcogens and sintering
Authors: Romanenko A I , Chebanova G E , Katamanin I N , Drozhzhin M V , Artemkina S B , Han M-K , Kim S-J , Wang Hongchao 
Published: December 2021

Abstract
The optimization of thermoelectric properties of the CuCrS

2
−
x

Se
x
(x = 0, 0.5, 1.0, 1.5, 2) samples was achieved by substitution in anionic sublattice and sintering at high temperature. The maximum power factor PF ∼ 0.3 mW (m·K)−2 among a series of samples with chalcogen substitution was obtained for CuCrS0.5Se1.5 sample at T = 300 K. The sintering made it possible to obtain the maximum value PF ∼ 2.1 mW (m·K)−2 for CuCrSe2 sample. This is due to a more than threefold increase in the thermopower S(T) in CuCrSe2 sample with a spin-orbital interaction in comparison with CuCrS0.5Se1.5 sample with the same optimal electrical conductivity σ (

σ
∼

100 S cm−1), but without spin-orbital interaction. In CuCrSe2 sample, sintering effectively reduced the σ to an optimal value, suppressed of the magnetic phase transition in the range of 50–100 K, and the weak localization were replaced by weak antilocalization indicating the appearance of strong spin-orbit interaction below 20 K. As a result, an additional contribution to the S(T) appeared due to the filtration of current carriers caused by the strong spin-orbit interaction. The effect of grain boundaries on the properties σ and S(T) of the samples was investigated. It was established that polycrystalline samples with a high sulfur content were low-conductivity materials consisting of high-conductivity crystallites with the charge carriers concentration

n
∼

10

20

cm−3 separated by low-conductivity grain boundaries with fluctuation-induced tunneling conductivity. Both the replacement of sulfur with selenium and sintering led to a decrease in the energy barriers connecting grain boundaries. Selenium-dominated samples (CuCrS0.5Se1.5 and CuCrSe2) had high electrical conductivity with negligible energy barriers between grain boundaries. Logarithmic quantum corrections to the electrical conductivity was observed below 20 K, which indicated a quasi-two-dimensional electron transport in these samples.
Chiral Majorana edge modes and vortex Majorana zero modes in superconducting antiferromagnetic topological insulator
Authors: Huang Beibing , Yang Xiaosen , Zhang Qinfang , Xu Ning 
Published: December 2021

Abstract
The antiferromagnetic topological insulator (AFTI) is topologically protected by the combined time-reversal and translational symmetry

T

c

. In this paper we investigate the effects of the s-wave superconducting pairings on the multilayers of AFTI, which breaks

T

c

symmetry and can realize quantum anomalous Hall insulator with unit Chern number. For the weakly coupled pairings, the system corresponds to the topological superconductor (TSC) with the Chern number C = ±2. We answer the following questions whether the local Chern numbers and chiral Majorana edge modes of such a TSC distribute around the surface layers. By the numerical calculations based on a theoretic model of AFTI, we find that when the local Chern numbers are always dominated by the surface layers, the wavefunctions of chiral Majorana edge modes must not localize on the surface layers and show a smooth crossover from spatially occupying all layers to only distributing near the surface layers, similar to the hinge states in a three dimensional second-order topological phases. The latter phase, denoted by the hinged TSC, can be distinguished from the former phase by the measurements of the local density of state. In addition we also study the superconducting vortex phase transition in this system and find that the exchange field in the AFTI not only enlarges the phase space of topological vortex phase but also enhances its topological stability. These conclusions will stimulate the investigations on superconducting effects of AFTI and drive the studies on chiral Majorana edge modes and vortex Majorana zero modes into a new era.
Synergetic effect of Si addition on mechanical properties in face-centered-cubic high entropy alloys: a first-principles study
Authors: Tsuru Tomohito , Lobzenko Ivan , Wei Daixiu 
Published: December 2021

Abstract
High-entropy alloys (HEA) have been receiving increased attention for their excellent mechanical properties. Our recent study revealed that Si-doped face-centered cubic (FCC) HEAs have great potential to improve both strength and ductility. Here, we carried out first-principles calculations in cooperation with Monte Carlo simulation and structural factor analysis to explore the effect of Si addition on the macroscopic mechanical properties. As a result, Si addition increased the local lattice distortion and the stacking fault energy (SFE). Furthermore, the short-range order formation in Si-doped alloy caused highly fluctuated SFE. Thus, the heterogeneous solid solution states in which low and high stacking fault regions are distributed into the matrix were nucleated. This unique feature in Si-doped FCC-HEA induces ultrafine twin formation in Si-doped alloys, which can be a dominant factor in improving both strength and ductility.
Small-diameter p-type SnS nanowire photodetectors and phototransistors with low-noise and high-performance
Authors: Chen Ruoling , Li Long , Jiang Long , Yu Xiangxiang , Zhu Desheng , Xiong Yan , Zheng Dingshan , Yang Wenxing 
Published: December 2021

Abstract
P-type nanostructured photodetectors and phototransistors have been widely used in the field of photodetection due to their excellent electrical and optoelectronic characteristics. However, the large dark current of p-type photodetectors will limit the detectivity. Herein, we synthesized small-diameter single-crystalline p-type SnS nanowires (NWs) and then fabricated single SnS NW photodetectors and phototransistors. The device exhibits low noise and low dark current, and its noise current power is as low as 2.4 × 10−28 A2. Under 830 nm illumination and low power density of 0.12 mW cm−2, the photoconductive gain, responsivity and detectivity of the photodetector are as high as 3.9 × 102, 2.6 × 102 A W−1 and 1.8 × 1013 Jones, respectively, at zero gate voltage. The rise and fall time of response are about 9.6 and 14 ms. The experimental results show that the small-diameter p-type SnS NWs have broad application prospects in high-performance and low-power photodetectors with high sensitivity, fast response speed and wide spectrum detection in the future.
Ion dynamics driven by a strongly nonlinear plasma wake
Authors: Khudiakov V K , Lotov K V , Downer M C 
Published: December 2021

Abstract
In plasma wakefield accelerators, the wave excited in the plasma eventually breaks and leaves behind slowly changing fields and currents that perturb the ion density background. We study this process numerically using the example of a Facility for Advanced aCcelerator Experimental Tests (FACET) experiment where the wave is excited by an electron bunch in the bubble regime in a radially bounded plasma. Four physical effects underlie the dynamics of ions: (1) attraction of ions toward the axis by the fields of the driver and the wave, resulting in formation of a density peak, (2) generation of ion-acoustic solitons following the decay of the density peak, (3) positive plasma charging after wave breaking, leading to acceleration of some ions in the radial direction, and (4) plasma pinching by the current generated during the wave-breaking. The interplay of these effects results in the formation of various radial density profiles, which are difficult to produce in any other way.
Neural network based fast prediction of β

N
limits in HL-2M
Authors: Zhao Y F , Liu Y Q , Wang S , Hao G Z , Wang Z X , Yang Z Y , Li B , Li J X , Chen H T , Xu M , Duan X R 
Published: December 2021

Abstract
Artificial neural networks (NNs) are trained, based on the numerical database, to predict the no-wall and ideal-wall β

N
limits, due to onset of the n = 1 (n is the toroidal mode number) ideal external kink instability, for the HL-2M tokamak. The database is constructed by toroidal computations utilizing both the equilibrium code CHEASE (Lütjens et al 1992 Comput. Phys. Commun.
69 287) and the stability code MARS-F (Liu et al 2000 Phys. Plasmas
7 3681). The stability results show that (1) the plasma elongation generally enhances both β

N
limits, for either positive or negative triangularity plasmas; (2) the effect is more pronounced for positive triangularity plasmas; (3) the computed no-wall β

N
limit linearly scales with the plasma internal inductance, with the proportionality coefficient ranging between 1 and 5 for HL-2M; (4) the no-wall limit substantially decreases with increasing pressure peaking factor. Furthermore, both the NN model and the convolutional neural network (CNN) model are trained and tested, producing consistent results. The trained NNs predict both the no-wall and ideal-wall limits with as high as 95% accuracy, compared to those directly computed by the stability code. Additional test cases, produced by the Tokamak Simulation Code (Jardin et al 1993 Nucl. Fusion
33 371), also show reasonable performance of the trained NNs, with the relative error being within 10%. The constructed database provides effective references for the future HL-2M operations. The trained NNs can be used as a real-time monitor for disruption prevention in the HL-2M experiments, or serve as part of the integrated modeling tools for ideal kink stability analysis.
Novel ionic bioartificial muscles based on ionically crosslinked multi-walled carbon nanotubes-mediated bacterial cellulose membranes and PEDOT:PSS electrodes
Authors: Wang Yaofeng , Wang Fan , Kong Yang , Wang Lei , Li Qinchuan 
Published: December 2021

Abstract
High-performance bioartificial muscles with low-cost, large bending deformation, low actuation voltage, and fast response time have drawn extensive attention as the development of human-friendly electronics in recent years. Here, we report a high-performance ionic bioartificial muscle based on the bacterial cellulose (BC)/ionic liquid (IL)/multi-walled carbon nanotubes (MWCNT) nanocomposite membrane and PEDOT:PSS electrode. The developed ionic actuator exhibits excellent electro-chemo-mechanical properties, which are ascribed to its high ionic conductivity, large specific capacitance, and ionically crosslinked structure resulting from the strong ionic interaction and physical crosslinking among BC, IL, and MWCNT. In particular, the proposed BC-IL-MWCNT (0.10 wt%) nanocomposite exhibited significant increments of Young’s modulus up to 75% and specific capacitance up to 77%, leading to 2.5 times larger bending deformation than that of the BC-IL actuator. More interestingly, bioinspired applications containing artificial soft robotic finger and grapple robot were successfully demonstrated based on high-performance BC-IL-MWCNT actuator with excellent sensitivity and controllability. Thus, the newly proposed BC-IL-MWCNT bioartificial muscle will offer a viable pathway for developing next-generation artificial muscles, soft robotics, wearable electronic products, flexible tactile devices, and biomedical instruments.
Current-induced self-organisation of mixed superconducting states
Authors: Brems Xaver S , Mühlbauer Sebastian , Córdoba-Camacho Wilmer Y , Shanenko Arkady A , Vagov Alexei , Albino Aguiar José , Cubitt Robert 
Published: December 2021

Abstract
Small-angle neutron scattering is used in combination with transport measurements to investigate the current-induced effects on the morphology of the intermediate mixed state (IMS) domains in the intertype superconductor niobium. We report the robust self-organisation of the vortex lattice domains to elongated parallel stripes perpendicular to the applied current in a steady-state. The experimental results for the formation of the superstructure are supported by theoretical calculations, which highlight important details of the vortex matter evolution. The investigation demonstrates a mechanism of a spontaneous pattern formation that is closely related to the universal physics governing the IMS in low-κ superconductors.
Improving photoluminescence, optical and electrical characteristics of PMMA films with gamma irradiation
Authors: Zaki M F , Shubayr N , Radwan R M , Alashban Y 
Published: December 2021

Abstract
Polymeric materials are macromolecules, essentially a combination of numerous repeated subunits. Polymers are innovative and advanced materials that currently have a strong impact on our daily lives. In recent years, polymer use has been prominent due to the materials’ distinctive properties; thus, they entered different fields of science, technology and industrial-biomedical applications.The improvement of photoluminescence, optical and electrical characteristics of non-conducting Poly(methyl methacrylate) (PMMA) films was studied. Upon gamma irradiation of various doses, the photophysical and electrical properties of PMMA films were investigated using photoluminescence spectroscopy, ultraviolet–visible (UV–vis) spectroscopy and the LCR Meter Bridge Circuit technique. The fluorescent response improved the photoluminescence (PL) spectral emission peaks according to gamma values. Strong fluorescence peaks appeared with the highest gamma dose. The UV–Vis results revealed a significant red-shift in the absorption edge as gamma doses increased. This shift exhibits a continuous decrease in the energy band gap values (from 3.50 to 2.60 eV for direct transition and from 3.05 to 1.55 eV for indirect transition). This was due to the formation of carbon clusters, which led to an increase in the electrical conductivity and improved the dielectric parameters of the irradiated PMMA films. Among a variety of measurements presented and discussed in the present study, the electrical measurements showed improved electrical characteristics of gamma-irradiated PMMA films.
SELCIE: a tool for investigating the chameleon field of arbitrary sources
Authors: Briddon Chad , Burrage Clare , Moss Adam , Tamosiunas Andrius 
Published: December 2021

Abstract
The chameleon model is a modified gravity theory that introduces an additional scalar field that couples to matter through a conformal coupling. This `chameleon field' possesses a screening mechanism through a nonlinear self-interaction term which allows the field to affect cosmological observables in diffuse environments whilst still being consistent with current local experimental constraints. Due to the self-interaction term the equations of motion of the field are nonlinear and therefore difficult to solve analytically. The analytic solutions that do exist in the literature are either approximate solutions and or only apply to highly symmetric systems. In this work we introduce the software package SELCIE (https://github.com/C-Briddon/SELCIE.git). This package equips the user with tools to construct an arbitrary system of mass distributions and then to calculate the corresponding solution to the chameleon field equation. It accomplishes this by using the finite element method and either the Picard or Newton nonlinear solving methods. We compared the results produced by SELCIE with analytic results from the literature including discrete and continuous density distributions. We found strong (sub-percentage) agreement between the solutions calculated by SELCIE and the analytic solutions.
Mixed dark matter: matter power spectrum and halo mass function
Authors: Parimbelli G. , Scelfo G. , Giri S.K. , Schneider A. , Archidiacono M. , Camera S. , Viel M. 
Published: December 2021

Abstract
We investigate and quantify the impact of mixed (cold and
warm) dark matter models on large-scale structure observables. In
this scenario, dark matter comes in two phases, a cold one (CDM) and
a warm one (WDM): the presence of the latter causes a suppression in
the matter power spectrum which is allowed by current constraints
and may be detected in present-day and upcoming surveys. We run a
large set of N-body simulations in order to build an efficient and
accurate emulator to predict the aforementioned suppression with
percent precision over a wide range of values for the WDM mass,
Mwdm, and its fraction with respect to the totality of dark
matter, fwdm. The suppression in the matter power spectrum is
found to be independent of changes in the cosmological parameters at
the 2% level for k≲ 10 h/Mpc and z≤ 3.5. In the
same ranges, by applying a baryonification procedure on both
ΛCDM and CWDM simulations to account for the effect of feedback, we
find a similar level of agreement between the two scenarios. We
examine the impact that such suppression has on weak lensing and
angular galaxy clustering power spectra. Finally, we discuss the
impact of mixed dark matter on the shape of the halo mass function
and which analytical prescription yields the best agreement with
simulations. We provide the reader with an application to galaxy
cluster number counts.
Emulation of baryonic effects on the matter power spectrum and constraints from galaxy cluster data
Authors: Giri Sambit K. , Schneider Aurel 
Published: December 2021

Abstract
Baryonic feedback effects consist of a major systematic for upcoming weak-lensing and galaxy-clustering surveys. In this paper, we present an emulator for the baryonic suppression of the matter power spectrum. The emulator is based on the baryonification model, containing seven free parameters that are connected to the gas profiles and stellar abundances in haloes. We show that with the baryonic emulator, we can not only recover the power spectra of hydro-dynamical simulations at sub-percent precision, but also establish a connection between the baryonic suppression of the power spectrum and the gas and stellar fractions in haloes. This connection allows us to predict the expected deviation from a dark-matter-only power spectrum using measured X-ray gas fractions of galaxy groups and clusters. With these measurements, we constrain the suppression to exceed the percent-level at k=0.1-0.4 h/Mpc and to reach a maximum of 20-28 percent at around k∼ 7 h/Mpc (68 percent confidence level). As a further step, we also perform a detailed parameter study and we present a minimum set of four baryonic parameters that are required to recover the scale and redshift dependence observed in hydro-dynamical simulations. The baryonic emulator can be found at https://github.com/sambit-giri/BCemu.
Ultralight bosons for strong gravity applications from simple Standard Model extensions
Authors: Freitas Felipe F. , Herdeiro Carlos A.R. , Morais António P. , Onofre António , Pasechnik Roman , Radu Eugen , Sanchis-Gual Nicolas , Santos Rui 
Published: December 2021

Abstract
We construct families, and concrete examples, of simple
extensions of the Standard Model that can yield ultralight real or
complex vectors or scalars with potential astrophysical
relevance. Specifically, the mass range for these putative
fundamental bosons (∼ 10-10-10-20 eV) would lead
dynamically to both new non-black hole compact objects (bosonic
stars) and new non-Kerr black holes, with masses of ∼ M⊙
to ∼ 1010 M⊙, corresponding to the mass range of
astrophysical black hole candidates (from stellar mass to
supermassive). For each model, we study the properties of the mass
spectrum and interactions after spontaneous symmetry breaking,
discuss its theoretical viability and caveats, as well as some of
its potential and most relevant phenomenological implications
linking them to the physics of compact objects.
Halo-independent analysis of direct dark matter detection through electron scattering
Authors: Chen Muping , Gelmini Graciela B. , Takhistov Volodymyr 
Published: December 2021

Abstract
Sub-GeV mass dark matter particles whose collisions with nuclei would not deposit sufficient energy to be detected, could instead be revealed through their interaction with electrons.
Analyses of data from direct detection experiments usually require assuming a local dark matter halo velocity distribution. In the halo-independent analysis method, properties of this distribution are instead inferred from direct dark matter detection data, which allows then to compare different data without making any assumption on the uncertain local dark halo characteristics. This method has so far been developed for and applied to dark matter scattering off nuclei. Here we demonstrate how this analysis can be applied to scattering off electrons.
Effect of proprioceptive stimulation using a soft robotic glove on motor activation and brain connectivity in stroke survivors
Authors: Nasrallah Fatima A , Mohamed Abdalla Z , Yap Hong Kai , Lai Hwa Sen , Yeow Chen-Hua , Lim Jeong Hoon 
Published: December 2021

Abstract

Objective. Soft-robotic-assisted training may improve motor function during post-stroke recovery, but the underlying physiological changes are not clearly understood. We applied a single-session of intensive proprioceptive stimulation to stroke survivors using a soft robotic glove to delineate its short-term influence on brain functional activity and connectivity. Approach. In this study, we utilized task-based and resting-state functional magnetic resonance imaging (fMRI) to characterize the changes in different brain networks following a soft robotic intervention. Nine stroke patients with hemiplegic upper limb engaged in resting-state and motor-task fMRI. The motor tasks comprised two conditions: active movement of fingers (active task) and glove-assisted active movement using a robotic glove (glove-assisted task), both with visual instruction. Each task was performed using bilateral hands simultaneously or the affected hand only. The same set of experiments was repeated following a 30 min treatment of continuous passive motion (CPM) using a robotic glove. Main results. On simultaneous bimanual movement, increased activation of supplementary motor area (SMA) and primary motor area (M1) were observed after CPM treatment compared to the pre-treatment condition, both in active and glove-assisted task. However, when performing the tasks solely using the affected hand, the phenomena of increased activity were not observed either in active or glove-assisted task. The comparison of the resting-state fMRI between before and after CPM showed the connectivity of the supramarginal gyrus and SMA was increased in the somatosensory network and salience network. Significance. This study demonstrates how passive motion exercise activates M1 and SMA in the post-stroke brain. The effective proprioceptive motor integration seen in bimanual exercise in contrast to the unilateral affected hand exercise suggests that the unaffected hemisphere might reconfigure connectivity to supplement damaged neural networks in the affected hemisphere. The somatosensory modulation rendered by the intense proprioceptive stimulation would affect the motor learning process in stroke survivors.