bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetoelectrics and multiferroics: theory, synthesis, characterisation, preliminary results and perspectives for all-optical manipulations
Authors: Bossini D , Juraschek D M , Geilhufe R M , Nagaosa N , Balatsky A V , Milanović M , Srdić V V , Šenjug P , Topić E , Barišić D , Rubčić M , Pajić D , Arima T , Savoini M , Johnson S L , Davies C S , Kirilyuk A 
Published: March 2023

Abstract
Solid state compounds exhibiting multiple and coupled macroscopic orders, named multiferroics, represent a challenge for both theoretical and experimental modern condensed-matter physics. Spins and the electric polarisation in conventional magnetic and ferroelectric materials can be manipulated on their fundamental timescales, by means of femtosecond laser pulses. In view of the resounding success and popularity of the all-optical approach, it is only natural to wonder about the application of this scheme to study the intrinsic coupling between spins and charges in multiferroics. Deeply fundamental questions arise: can ultrashort laser pulses deterministically activate, enhance or suppress the magnetoelectric coupling on the femtosecond timescale? Can these processes be triggered in a fully coherent fashion, thus being unrestrained by any thermal load? Which mechanism of spin-charge coupling is most favourable to overcome these overarching and daunting challenges? This problem is interdisciplinary in nature, requiring contributions from materials science and condensed matter physics from both theoretical and experimental perspectives. High-quality materials suitable for optical investigations have to be identified, synthetized and characterised. General and valid models offer then a guide to the plethora of possible light-induced processes, resulting in the desired ultrafast multiferroic manipulations. Finally, healthy experimental schemes, able to unambiguously track the ultrafast dynamics of either the ferroelectric or the magnetic order parameter have to be developed and implemented. Our motivation to write this review is to lay a broad and multidisciplinary foundation, which may be employed as a starting point for non-equilibrium approaches to the manipulation of the multiferroicity on the femtosecond timescale. This was also one of the main goals of the COST Action MAGNETOFON, whose network constitutes the core of the authors of this review. The present work thus represents a part of the scientific legacy of MAGNETOFON itself.
Optimization of fs + ps double-pulse sequence parameters for laser-assisted chemical etching of microchannels in fused silica
Authors: Yao Qian , Song Juan , Yin Weiyi , Shi Huiqiang , Yao Heng , Su Zihuai , Dai Ye 
Published: March 2023

Abstract
Developing laser fabricating technology to improve the etching rate of microchannels is of great significance for the development of microfluidic devices. In this paper, the laser processing parameters of the fs + ps double-pulse sequence, including temporal delay and pulse energy ratio, have been investigated to optimize the fabrication of microchannels, in order to obtain a high etching rate. As a result, the optimal energy ratio could be obtained at
Efs:Eps

= 2:1 in negative delays. Furthermore, the etching rate of microchannels was significantly improved by 40.8% compared with those written by fs + fs double-pulse sequence with an energy ratio of 1:1. This improvement is possibly because fs sub-pulse excited seed electron may trigger impact ionization via an efficient energy absorption process within the following ps sub-pulse, this energy accumulation and subsequent thermal diffusion lead to an increase of the modified area. The aforementioned results possibly offer an effective route to improve the etching rate of microchannels which is in favor of accelerating the fabrication of three-dimensional microfluidic devices.
Particle size distribution measurements of widely distributed carbonyl iron powder particles in concentrated suspensions using ultrasonic attenuation
Authors: Wei Qilong , Yang Qiang , Gao Wei 
Published: March 2023

Abstract
In this paper, particle size distribution (PSD) of widely distributed carbonyl iron powder (CIP) particles in concentrated suspensions was measured using the ultrasonic attenuation technology to analyze their dispersion behaviors. Importantly, their zeta potential was measured using electroacoustic technology. Both visco-inertial and scattering mechanisms were considered while measuring the PSD of these particles with primary sizes ranging from about 100 nm to 10 μm. As a result, the opposite evolution of the PSD curves was observed for nanoscale particles and microparticles, namely, d
01 increased and d
99 decreased when the concentration increased from 15 wt% to 35 wt%, whereas the trend was reversed when the concentration increased from 35 wt% to 75 wt%. This outcome means that changes in concentration cause small and large particles to have opposite dispersion behaviors. The zeta potential of the particles was negative, with absolute values not higher than 22 mV, whereas particle concentration and carrier liquids exerted some effects. This opposite evolution was found first while measuring PSD in concentrated suspensions, where non-Derjaguin, Landau, Verwey, and Overbeek interactions could markedly influence the dispersion behaviors of the widely distributed CIP particles. These results might bring forward some challenges to disperse these particles fully for some advanced applications.
Global well-posedness of 3D inhomogeneous Navier–Stokes system with small unidirectional derivative
Authors: Paicu Marius , Zhu Ning 
Published: March 2023

Abstract
In Liu and Zhang (2020 Arch. Ration. Mech. Anal.
235 1405–44); Liu et al (2020 Arch. Ration. Mech. Anal.
238 805–43), the authors proved that as long as the one-directional derivative of the initial velocity is sufficiently small in some scaling invariant spaces, then the (anisotropic) Navier–Stokes (NS) system has a unique global solution. The goal of this paper is to extend this type of result to the 3D inhomogeneous (density-dependent) NS system. More precisely, given initial density such that

a
0

≜

1

ρ
0

−
1
∈

B

p
,
1

3
p

(

R

3

)

and the initial velocity

u
0

=
(

u
0
h

,

u
0
3

)
∈

B

p
,
1

−
1
+

2
p

,

1
p

(

R

3

)
,

with

u
0
h

belonging to

H
1

(

R

3

)

, then the inhomogeneous NS system has a unique global solution provided that

(

∥

a
0

∥

B

p
,
1

3
p

+
∥

Λ
h

−
1

∂
3

u
0

∥

B

p
,
1

−
1
+

2
p

,

1
p

)

⋅
f
(

u
0

)

being sufficiently small for some bounded function f depending on

∥

u
0

∥

p
,
1

−
1
+

2
p

,

1
p

and

∥

u
0
h

∥

H
1

. This provide a more general result that of Chemin et al (2014 Commun. Math. Phys.
272 529–66); Chemin and Zhang (2015 Commun. PDE
40 878–96).
The outflow problem for the radiative and reactive gas: existence, stability and convergence rate
Authors: Yin Haiyan , Zhu Changjiang 
Published: March 2023

Abstract
In this paper, we show that the small-amplitude stationary solutions are time-asymptotically stable to the half-space problem for the one-dimensional radiative and reactive gas (pressure

p
=
R
ρ
θ
+

a
3

θ

4

, internal energy

e
=

C

v

θ
+

a
ρ

θ

4

) provided that the initial perturbation is sufficiently small in some weighted Sobolev spaces. We also obtain the convergence rate of global solutions toward corresponding stationary solutions. The proofs are given by a weighted energy method. A key point is to capture the positivity of the energy dissipation functional and boundary terms with suitable space weight functions and using the precise estimates about stationary solutions.
Fluid compartments influence elastography of the aging mouse brain
Authors: Ge Gary R , Rolland Jannick P , Song Wei , Nedergaard Maiken , Parker Kevin J 
Published: March 2023

Abstract

Objective. Elastography of the brain has the potential to reveal subtle but clinically important changes in the structure and composition as a function of age, disease, and injury. Approach. In order to quantify the specific effects of aging on mouse brain elastography, and to determine the key factors influencing observed changes, we applied optical coherence tomography reverberant shear wave elastography at 2000 Hz to a group of wild-type healthy mice ranging from young to old age. Main results. We found a strong trend towards increasing stiffness with age, with an approximately 30% increase in shear wave speed from 2 months to 30 months within this sampled group. Furthermore, this appears to be strongly correlated with decreasing measures of whole brain fluid content, so older brains have less water and are stiffer. Rheological models are applied, and the strong effect is captured by specific assignment of changes to the glymphatic compartment of the brain fluid structures along with a correlated change in the parenchymal stiffness. Significance. Short-term and longer-term changes in elastography measures may provide a sensitive biomarker of progressive and fine-scale changes in the glymphatic fluid channels and parenchymal components of the brain.
Uncertainty quantification in the assessment of human exposure to pulsed or multi-frequency fields
Authors: Giaccone Luca 
Published: March 2023

Abstract

Objective: pulsed fields or waveforms with multi-frequency content have to be assessed with suitable methods. This paper deals with the uncertainty quantification associated to these methods. Approach: among all possible approaches, the weighted peak method (WPM) is widely employed in standards and guidelines, therefore, in this paper, we consider its implementation both in time domain and frequency domain. For the uncertainty quantification the polynomial chaos expansion theory is used. By means of a sensitivity analysis, for several standard waveforms, the parameters with more influence on the exposure index are identified and their sensitivity indices are quantified. The output of the sensitivity analysis is used to set up a parametric analysis with the aim of evaluating the uncertainty propagation of the analyzed methods and, finally, also several measured waveforms generated by a welding gun are tested. Main results: it is shown that the time domain implementation of the weighted peak method provides results in agreement with the basilar mechanisms of electromagnetic induction and electrostimulation. On the opposite, the WPM in frequency domain is found to be too sensitive to parameters that should not influence the exposure index because its weight function includes sharp variations of the phase centered on real zeros and poles. To overcome this issue, a new definition for the phase of the weight function in frequency domain is proposed. Significance: it is shown that the time domain implementation of the WPM is the more accurate and precise. The standard WPM in frequency domain has some issues that can be avoided with the proposed modification of the phase definition of the weight function. Finally, all the codes used in this paper are hosted on a GitHub and can be freely accessed at https://github.com/giaccone/wpm_uncertainty.
A tomographic reconstruction algorithm for cross-sectional imaging of IMRT beams from six projections
Authors: Pivot Odran , Pittet Patrick , Clackdoyle Rolf , Desbat Laurent , Rit Simon 
Published: March 2023

Abstract

Objective. Patient-specific Quality Assurance (QA) measurements are of key importance in radiotherapy for safe and efficient treatment delivery and allow early detection of clinically relevant errors. Such QA processes remain challenging to implement for complex Intensity Modulated Radiation Therapy (IMRT) radiotherapy fields delivered using a multileaf collimator (MLC) which often feature small open segments and raise QA issues similar to those encountered in small field dosimetry. Recently, detectors based on long scintillating fibers have been proposed to measure a few parallel projections of the irradiation field with good performance for small field dosimetry. The purpose of this work is to develop and validate a novel approach to reconstruct MLC-shaped small irradiation fields from six projections. Approach. The proposed field reconstruction method uses a limited number of geometric parameters to model the irradiation field. These parameters are iteratively estimated with a steepest descent algorithm. The reconstruction method was first validated on simulated data. Real data were measured with a water-equivalent slab phantom equipped with a detector made of 6 scintillating-fiber ribbons placed at 1 m from the source. A radiochromic film was used to acquire a reference measurement of a first dose distribution in the slab phantom at the same source-to-detector distance and the treatment planning system (TPS) provided the reference for another dose distribution. In addition, simulated errors introduced on the delivered dose, field location and field shape were used to evaluate the ability of the proposed method to efficiently identify a deviation between the planned and delivered treatments. Main results. For a first small IMRT segment, 3%/3 mm, 2%/2 mm and 2%/1 mm gamma analysis conducted between the reconstructed dose distribution and the dose measured with radiochromic film exhibited pass rates of 100%, 99.9% and 95.7%, respectively. For a second and smaller IMRT segment, the same gamma analysis performed between the reconstructed dose distribution and the reference provided by the TPS showed pass rates of 100%, 99.4% and 92.6% for the 3%/3 mm, 2%/2 mm and 2%/1 mm gamma criteria, respectively. Gamma analysis of the simulated treatment delivery errors showed the ability of the reconstruction algorithm to detect a 3% deviation between the planned and delivered doses, as well as shifts lower than 7 mm and 3 mm when considering an individual leaf and a whole field shift, respectively. Significance. The proposed method allows accurate tomographic reconstruction of IMRT segments by processing projections measured with six scintillating-fiber ribbons and is suitable for water-equivalent real-time small IMRT segments QA.
Fusion reactivities with drift bi-Maxwellian ion velocity distributions
Authors: Xie Huasheng , Tan Muzhi , Luo Di , Li Zhi , Liu Bing 
Published: March 2023

AbstractThe calculation of fusion reactivity involves a complex six-dimensional integral that takes into account the fusion cross section and velocity distributions of two reactants. However, a more simplified one-dimensional integral form can be useful in certain cases, such as for studying fusion yield or diagnosing ion energy spectra. This simpler form has been derived in a few special cases, such as for a combination of two Maxwellian distributions, a beam-Maxwellian combination, and a beam-target combination, and can greatly reduce computational costs. In this study, it is shown that the reactivity for two drift bi-Maxwellian reactants with different drift velocities, temperatures, and anisotropies can also be reduced to a one-dimensional form, unifying existing derivations into a single expression. This result is used to investigate the potential enhancement of fusion reactivity due to the combination of beam and temperature anisotropies. For relevant parameters in fusion energy, the enhancement factor can be larger than 20%, which is particularly significant for proton-boron (p–B11) fusion, as this factor can have a significant impact on the Lawson fusion gain criteria.
SOLPS-ITER simulations of a vapour box design for the linear device Magnum-PSI
Authors: Gonzalez J , Westerhof E , Morgan T W 
Published: March 2023

Abstract
A vapour box (VB) is a physical device currently being considered to reduce the high heat and particle fluxes typically impacting the divertor in tokamaks. This system usually consists of a series of boxes that retains neutral particles to increase the amount of collision events with the impacting plasma. The neutral particles come from recycling and recombination of the plasma, gas puffing inside the box and by the evaporation of a liquid metal, typically Li or Sn. Currently, an VB is being constructed for testing in the linear plasma generator Magnum-PSI, operated at DIFFER. Its modular design will allow for open (not enclosing the target) and closed (enclosing the target) configurations, as well as evaporating a liquid metal to create a vapour cloud inside the box. The experiments carried out with this device will investigate its capabilities to reduce the plasma flux towards the target. This work presents a numerical study performed with SOLPS-ITER about the effectiveness of the current VB design in its open configuration to retain neutrals and its effect on the plasma beam properties. This is a first step before validation against experiments and studying closed configurations to ensure that the VB can successfully operate in a wide range of plasma parameters. Simulations show that the VB is capable of retaining neutrals and reducing fluxes to the target without requiring additional gas puffing in High and Low plasma flux scenarios. When lithium is evaporated from inside the box, the hydrogen plasma is completely extinguished and replaced by a low temperature Li plasma with lower flux. The fraction of Li and Li+ transported upstream the VB is three orders of magnitude below the amount evaporated form the central box, as most of the lithium is condensed in the side boxes and another small portion (two orders of magnitude below the amount evaporated) is deposited on the target. The VB design in its open configuration can mitigate incoming plasma peak heat flux by

0.6

M
W

m

−
2

, which represents a fraction of

75
%

and

81
%

for the High and Low flux scenarios. This effect is expected to be higher when a closed configuration is employed, which could result in a significant reduction of heat fluxes on the divertor of tokamaks once that this design is extrapolated to the toroidal geometry, with just a minimal amount of Li and Li+ reaching the core.
Multiple-image encryption algorithm based on Sarrus rule and 3D Fibonacci matrix
Authors: Zhang Xiaoqiang , Liu Mi , Tian Jingxi 
Published: March 2023

Abstract
Using images to transmit information becomes more common in the new era, but the image information can easily be stolen and tampered with the malicious damage during transmission. In this paper, firstly, inspired by the famous Sarrus rule the theory of linear algebra theory, the Sarrus model is established to scramble images; secondly, the pixel positions of plain images are scrambled with the established Sarrus model to obtain the stereo scrambled matrix; thirdly, two-dimensional Fibonacci matrix is extended to three-dimensional (3D) space; finally, the image matrix is divided into cubes which are diffused by the 3D Fibonacci matrix. Experimental analyses indicate that the new algorithm has the characteristics of large key space, high key sensitivity, high efficiency and can resist to the plaintext attacks, statistical attacks, etc.
MHD effects of liquid metal flows through multiple electrically coupling ducts with U-turn bends in fusion blankets
Authors: Lv Xinting , Zhang Xiujie , Wang Lei 
Published: March 2023

Abstract
The investigation of liquid metal (LM) magnetohydrodynamic (MHD) flows through multiple electrically coupling ducts with U-turn bends is of crucial importance for accurately predicting the thermal-hydraulic performance of LM blankets in fusion reactors. Moreover, this duct configuration is often adopted in liquid blanket designs. Here, the combination effects of the MHD coupling, 3D MHD and inclined external magnetic fields on LM MHD flows through the multiple coupling ducts with different aspect ratios and wall conductance ratios are systematically investigated by numerical simulations. The results indicate that the MHD pressure gradient caused by MHD coupling effect decreases but the 3D MHD pressure gradient increases firstly and then decreases as the inclined angles of external magnetic fields increase. In addition, the results also indicate that the normalized pressure gradient can be reduced by increasing the wall conductance ratio (

C

w

) through the increase of the wall thickness. Furthermore, an important finding is that the pressure gradients caused by the MHD coupling decrease with the increases of aspect ratios (b/a) of ducts, while the 3D MHD pressure gradient when b/a = 16 increases to an excessive large degree about 40 times of the pressure gradient in a single conductive duct. The related investigation results will provide a theoretical support for the liquid blanket designs in fusion reactors and deepen our understanding on the LM MHD effects.
Ultra wideband bandstop plasmonic filter in the NIR region based on stub resonators
Authors: Zegaar Imane , Hocini Abdesselam , Bensalah Hocine , Harhouz Ahlam , Khedrouche Djamel , Lahoubi Mahieddine 
Published: March 2023

Abstract
In this study, we propose an ultra-wideband bandstop filter (UWB-BSF) using a plasmonic MIM waveguide coupled with a stub cavity that is investigated using finite-difference time-domain (FDTD). Air and silver are used as insulators and metals, respectively; silver is characterized by the Drude model. The structure can filter the optical telecommunication wavelengths of 1550 nm and 1310 nm. The transmission peak and the resonance wavelength of the basic structure can be tuned by varying the stub resonator’s length and width. In order to improve the filtering function of the bandstop filter at broad bandwidth in the NIR region with maximum transmission peak, the number of stub resonators is increased to two, three, and four stubs with properly studied lengths and a proper horizontal distance between each two stubs. The bandwidth is enhanced from 350 nm, with two stubs, to 620 nm, with three stubs, and 770 nm, with four stubs, respectively. The corresponding filtered wavelength ranges are [1600 nm–1950 nm], [1330 nm–1950 nm] and [1180 nm–1950 nm] respectively. Moreover, with the increase in the number of stubs, the center wavelength achieves a blue shift to lower wavelengths. Further, the paper provides significant applications for plasmonic bandstop filters in highly integrated optical circuits.
Multidirectional galloping-based wind energy harvester based on a cylindrical cantilever beam and multi-tooth blunt body
Authors: Lu Caijiang , Wu Gang , Xu Changbao , Jiang Xueling , Tian Fei , Liu Jie , Wang Tao , Wang Xi , Fu Guoqiang 
Published: March 2023

Abstract
To improve the response-ability of the energy harvester to multi-directional wind, this paper proposes a galloping-based wind energy harvester by fixing a multi-tooth blunt body at the free end of a cylindrical cantilever beam, which consists of a long-straight FeGa thin cylinder and a piezoelectric tube. Combining the structural symmetry advantages of the multi-tooth blunt body and piezoelectric cylinder cantilever, the harvester can respond well to the wind from all directions of the two-dimensional plane. In the simulation and experiment, detailed comparative studies are carried out on the harvesters with square (four-tooth), six-tooth, eight-tooth, ten-tooth, and twelve-tooth blunt bodies. Within the wind speed range of 1.5 ∼ 8 m s−1, the results show that the harvester with a six-tooth blunt body has the best multidirectional wind response performance. When the wind speed is 8 m s−1, the output power of the harvester with a six-tooth blunt body improves by ∼43% more than that of the harvester with a traditional square blunt body. The design idea of the proposed harvester provides a direction for the future in-depth study of multidirectional piezoelectric wind energy harvesting.