bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confronting Vegard’s rule in Ge1−x
Sn
x
epilayers: from fundamentals to the effect of defects
Authors: Magalhães S , Dias M , Nunes B , Oliveira F , Cerqueira M F , Alves E 
Published: April 2022

Abstract
Comprehensive and systematic study challenging the application of Vegard’s rule to germanium tin solid solutions grown on germanium buffer layers and 100 silicon substrates is presented. The binary’s lattice parameters, composition and respective uncertainties are determined through x-ray diffraction via reciprocal space mapping technique employing newly developed software. The tin content is confirmed by Rutherford backscattering spectrometry and energy dispersive x-ray spectroscopy. The statistical agreement between the tin contents derived by the different structural characterization techniques suggests the binary to follow generically the Vegard’s rule in the range of low Sn molar fractions (<5%). Phase separation, Sn segregation, point defects, post-growing oxygen impurities, and deteriorated surface morphology are found to be relevant within the ∼200 nm germanium tin films. Although, complex mechanisms triggering composition/strain heterogeneities are found in the analysed Ge1−x
Sn
x
compounds, the deviation from the perfect crystals is suggested to be not enough to distort the in- and out-of-plane lattice parameters away from its empirical linear combination.
Lifetime estimation model of vapor cells in atomic magnetometers
Authors: Liu Zhi , Zou Sheng , Yin Kaifeng , Zhou Binquan , Ning Xiaolin , Yuan Heng 
Published: April 2022

Abstract
A lifetime estimation model is proposed by characterizing the consumption of the components inside the atomic vapor cells in this work. The buffer gas leakage and alkali metal consumption in vapor cells will significantly destroy the performance of atomic magnetometers. Combining the light absorption method and aging experiments, the deterioration of helium pressure, rubidium vapor density, and cell wall transmittance were obtained to construct the lifetime estimation model that depends on time, working temperature, and initial contents. Then, the causes and consequences of these deteriorations were analyzed, and the combination of theoretical analysis and experimental data showed that the vapor cell invalidation caused by these factors conforms to the Weibull distribution. In order to establish the relationship between the component consumption and the performance of the magnetometer constituted by this cell, a single-beam magnetometer prototype was designed for sensitivity testing. Experiments have shown that the sensitivity of magnetometer is rapidly deteriorating after operating 600 h under 150 °C, which is mainly related to alkali metal consumption. Additionally, 200 °C is a trade-off aging experimental temperature between the aging efficiency and the stability of the cell. The proposed model can be applied to optimize the lifetime of the vapor cells used not only in magnetometers but also in gyroscopes and atomic clocks.
Electroweak phase transition in the presence of hypermagnetic field and the generation of gravitational waves
Authors: Abedi H , Ahmadvand M , Gousheh S S 
Published: April 2022

Abstract
We investigate the effects of a large-scale background hypermagnetic field on the electroweak phase transition (EWPT). We propose a model in which an effective weak angle varies during the EWPT and upon its use we show that, although for the majority of the parameter space the phase transition is a crossover, there are tiny regions in which the phase transition occurs in two steps and can be first-order. We obtain all of the important quantities characterizing the details of the first-order phase transition, including the latent heat, transition temperature and duration. We then calculate the gravitational wave energy spectrum generated during the first-order part of the EWPT and find that, for strong enough background hypermagnetic fields, these signals can be detected by the Ultimate-DECIGO interferometer.
Laser induced enhanced coupling between photons and squeezed magnons in antiferromagnets
Authors: Henriques J C G , Antão T V C , Peres N M R 
Published: April 2022

Abstract
In this paper we consider a honeycomb antiferromagnet subject to an external laser field. Obtaining a time-independent effective Hamiltonian, we find that the external laser renormalizes the exchange interaction between the in-plane components of the spin-operators, and induces a synthetic Dzyaloshinskii–Moria interaction (DMI) between second neighbors. The former allows the control of the magnon dispersion’s bandwidth and the latter breaks time-reversal symmetry inducing non-reciprocity in momentum space. The eigen-excitations of the system correspond to squeezed magnons whose squeezing parameters depend on the properties of the laser. When studying how these spin excitations couple with cavity photons, we obtain a coupling strength which can be enhanced by an order of magnitude via careful tuning of the laser’s intensity, when compared to the case where the laser is absent. The transmission plots through the cavity are presented, allowing the mapping of the magnons’ dispersion relation.
A phenomenological theory of superconductor diodes
Authors: He James Jun , Tanaka Yukio , Nagaosa Naoto 
Published: April 2022

Abstract
Nonreciprocal responses in noncentrosymmetric systems contain a broad range of phenomena. Especially, non-dissipative and coherent nonreciprocal transport in solids is an important fundamental issue. The recent discovery of superconductor (SC) diodes under external magnetic fields, where the magnitude of the critical current changes as the direction is reversed, significantly boosted this research area. However, a theoretical understanding of such phenomena is lacking. Here, we provide theoretical descriptions of SC diodes with a generalized Ginzburg–Landau method. The theory is applied to Rashba spin–orbit coupled systems, where analytical relations between the nonreciprocal critical currents and the system parameters are achieved. Numerical calculations with mean-field theory are also obtained to study broader parameter regions. These results offer a rather general description and design principles of SC diodes.
Quantitative laser-based x-ray fluorescence and particle-induced x-ray emission
Authors: Boivin Frédéric , Vallières Simon , Fourmaux Sylvain , Payeur Stéphane , Antici Patrizio 
Published: April 2022

Abstract
In this work, we demonstrate the feasibility of quantitative laser-based x-ray fluorescence (XRF) combined with particle-induced x-ray emission (PIXE) (called XPIF for x-ray and particle-induced fluorescence) spectroscopy analysis for elemental composition in solid samples. A multi-hundred TW laser system accelerated protons and produced x-rays that were impinging on solid samples, inducing characteristic line emissions of the elements contained in the material. The x-ray yield obtained from the characteristic emissions for each element can be related to its mass concentration using both the thick PIXE and thick XRF formalism. This is performed by using of an iterative numerical procedure. We tested the validity of our method on three homogeneous metallic materials, stainless steel, bronze and brass. The mass proportions of these samples retrieved by our analysis (XPIF) is within the errors bars compared with a commercial energy dispersive x-ray spectrometer.
Probing the properties of dense nuclear matter with photon conversions at NICA
Authors: Burmasov N , Kryshen E , Ivanishchev D , Kotov D , Malaev M , Riabov V , Ryabov Y 
Published: April 2022

Abstract
Photons serve as valuable probes of the properties of the hot and dense nuclear matter created in collisions of heavy ions. Thermal photon spectra at RHIC and LHC energies indicate that the temperature of the produced medium far exceeds the temperature of the phase transition to the quark-gluon plasma in lattice QCD calculations. Measurements of thermal photon spectra in heavy ion collisions at lower energies at the future NICA collider may help to trace the transition from partonic to hadronic degrees of freedom. In this contribution, feasibility studies on thermal photon measurements using the photon conversion method in the future MPD experiment at NICA will be reviewed. In this work, a possibility to increase photon reconstruction efficiency with a dedicated conversion layer is presented and feasibility to probe the material budget of the experiment with converted photons is discussed.
Two dimensional relativistic electron in a constant magnetic field
Authors: Bentalha Z 
Published: April 2022

Abstract
The (2+1)-dimensional Dirac equation for an electron in a constant magnetic field is considered. Exact solutions of this equation along with the corresponding energy spectrum are derived in a concise form. Among these solutions, we noticed that the lowest Landau level wavefunction corresponds to an anti-electron (an electron with a negative energy). The latter appears because special relativity allows solutions with negative energies. This means that a relativistic electron (matter) in a uniform magnetic field, at the lowest Landau level, is mutated to an anti-electron (anti-matter). This is a good finding for those that are interested in anti-matter applications.
Targeted Search for Fast Radio Bursts with Nanshan 26 m Radio Telescope
Authors: Mao Jian-Wei , Yuan Jian-Ping , Wen Zhi-Gang , Li Jian , Wang Na , Wang Pei , Yuen Rai , Wang Yu-Bin , Zhai Nan-Nan , Liu Zhi-Yong , Chen Mao-Zheng , Li Guang-Hui 
Published: April 2022

Abstract
Fast radio bursts (FRBs) are radio transients that are bright and have short duration, with their physical mechanism not being fully understood. We conducted a targeted search for bursts from FRB 20201124A between 2021 June 2 and July 20. High time-resolution data were collected for 104.5 hr using the ROACH2-based digital backend. We introduce the details of our FRB search pipeline which is based on HEIMDALL and FETCH. Testing of the injected mock FRBs search could help us better understand the performance of the pipelines, and improve the search algorithms and classifiers. To study the efficiency of our pipeline, 5000 mock FRBs were injected into the data and searched using the pipeline. The results of the mock FRB search show that our pipeline can recover almost all (≳90%) the injected mock FRBs above a signal-to-noise ratio (S/N) threshold of 15, and the performance is still acceptable (≳80%) for injected S/Ns from 10 to 15. The recovery fraction displays relations with S/N, dispersion measure and pulse width. No bursts were detected from FRB 20201124A in the middle of 2021. The non-detection of FRB 20201124A may be due to its quiet phase window or no emission above the threshold of the Nanshan telescope.
Optimizing the montage for cerebellar transcranial alternating current stimulation (tACS): a combined computational and experimental study
Authors: Sadeghihassanabadi Fatemeh , Misselhorn Jonas , Gerloff Christian , Zittel Simone 
Published: April 2022

Abstract

Objective. The application of cerebellar transcranial alternating current stimulation (tACS) is limited by the absence of commonly agreed montages and also the presence of unpleasant side effects. We aimed to find the most effective cerebellar tACS montage with minimum side effects (skin sensations and phosphenes). Approach. We first simulated cerebellar tACS with five montages (return electrode on forehead, buccinator, jaw, and neck positions, additionally focal montage with high-definition ring electrodes) to compare induced cerebellar current, then stimulated healthy participants and evaluated side effects for different montages and varying stimulation frequencies. Main results. The simulation revealed a descending order of current density in the cerebellum from forehead to buccinator, jaw, neck and ring montage respectively. Montages inducing higher current intensity in the eyeballs during the simulation resulted in stronger and broader phosphenes during tACS sessions. Strong co-stimulation of the brainstem was observed for the neck. Skin sensations did not differ between montages or frequencies. We propose the jaw montage as an optimal choice for maximizing cerebellar stimulation while minimizing unwanted side effects. Significance. These findings contribute to adopting a standard cerebellar tACS protocol. The combination of computational modelling and experimental data offers improved experimental control, safety, effectiveness, and reproducibility to all brain stimulation practices.
Interpretable functional specialization emerges in deep convolutional networks trained on brain signals
Authors: Hammer J , Schirrmeister R T , Hartmann K , Marusic P , Schulze-Bonhage A , Ball T 
Published: April 2022

AbstractObjective.Functional specialization is fundamental to neural information processing. Here, we study whether and how functional specialization emerges in artificial deep convolutional neural networks (CNNs) during a brain–computer interfacing (BCI) task.Approach.We trained CNNs to predict hand movement speed from intracranial electroencephalography (iEEG) and delineated how units across the different CNN hidden layers learned to represent the iEEG signal.Main results.We show that distinct, functionally interpretable neural populations emerged as a result of the training process. While some units became sensitive to either iEEG amplitude or phase, others showed bimodal behavior with significant sensitivity to both features. Pruning of highly sensitive units resulted in a steep drop of decoding accuracy not observed for pruning of less sensitive units, highlighting the functional relevance of the amplitude- and phase-specialized populations.Significance.We anticipate that emergent functional specialization as uncovered here will become a key concept in research towards interpretable deep learning for neuroscience and BCI applications.
First-passage Brownian functionals with stochastic resetting
Authors: Singh Prashant , Pal Arnab 
Published: April 2022

Abstract
We study the statistical properties of first-passage time functionals of a one dimensional Brownian motion in the presence of stochastic resetting. A first-passage functional is defined as

V
=

∫

0

t

f

Z

[

x

(

τ

)

]

where t
f is the first-passage time of a reset Brownian process x(τ), i.e., the first time the process crosses zero. In here, the particle is reset to x

R
> 0 at a constant rate r starting from x
0 > 0 and we focus on the following functionals: (i) local time

T

l
o
c

=

∫

0

t

f

d
τ
δ

(

x
−

x

R

)

, (ii) residence time

T

r
e
s

=

∫

0

t

f

d
τ
θ

(

x
−

x

R

)

, and (iii) functionals of the form

A

n

=

∫

0

t

f

d
τ

[

x

(

τ

)

]

n

with n > −2. For first two functionals, we analytically derive the exact expressions for the moments and distributions. Interestingly, the residence time moments reach minima at some optimal resetting rates. A similar phenomena is also observed for the moments of the functional A

n
. Finally, we show that the distribution of A

n
for large A

n
decays exponentially as

∼

exp

−

A

n

/

a

n

for all values of n and the corresponding decay length a

n
is also estimated. In particular, exact distribution for the first passage time under resetting (which corresponds to the n = 0 case) is derived and shown to be exponential at large time limit in accordance with the generic observation. This behavioural drift from the underlying process can be understood as a ramification due to the resetting mechanism which curtails the undesired long Brownian first passage trajectories and leads to an accelerated completion. We confirm our results to high precision by numerical simulations.
Apparent heating due to imperfect calorimetric measurements
Authors: Donvil Brecht , Ankerhold Joachim 
Published: April 2022

Abstract
Performing imperfect or noisy measurements on a quantum mechanical system both impacts the measurement outcome and the state of the system after the measurement. In this paper we are concerned with imperfect calorimetric measurements. In calorimetric measurements one typically measures the energy of a thermal environment to extract information about the system. In our setting the measurement is imperfect due to noise directly acting on the detector. Concretely, we consider an additional noise bath such that its energy is measured simultaneously with the calorimeter energy. Under weak coupling assumptions, we derive a hybrid master equation for the state of the system and the detected energy and find that the presence of the noise bath manifests itself by modifying the jump rates of the reduced system dynamics. We study an example of a driven qubit interacting with a resonant boson calorimeter and demonstrate that increasing the additional noise leads to an apparent reduction in the power flowing from qubit to calorimeter and thus to a seemingly detected heating up of the calorimeter.
Dynamical charge inversion of polarization correlation vortex in propagating vector speckle field
Authors: Pandit Himangi J , Kumar Vijay , Singh R P 
Published: April 2022

Abstract
A study on first-order polarization correlation in propagating vector speckle fields is carried out. Vector speckle field, generated by scattering of Poincare beam, is propagated through a spherical and a cylindrical lens. The first-order polarization correlation is experimentally constructed from intensity images of vector speckle fields at various planes before and after the focal plane. We have shown with supporting experimental and simulation results that polarization correlation vortex experiences charge inversion while vector speckle field propagates through a cylindrical lens. The importance of this study relies on the fact that it provides insight into one of the important properties of light, i.e. the phase between the orthogonal polarization components, how it evolves as the optical field propagates through various optical components. This study could find application in optical data processing, imaging, sensing, speckle meteorology, phase unwrapping, optical communication, etc.
Interventions to reduce falls in hospitals: a systematic review and meta-analysis
Authors: Morris Meg E , Webster Kate , Jones Cathy , Hill Anne-Marie , Haines Terry , McPhail Steven , Kiegaldie Debra , Slade Susan , Jazayeri Dana , Heng Hazel , Shorr Ronald , Carey Leeanne , Barker Anna , Cameron Ian 
Published: April 2022

AbstractBackgroundFalls remain a common and debilitating problem in hospitals worldwide. The aim of this study was to investigate the effects of falls prevention interventions on falls rates and the risk of falling in hospital.DesignSystematic review and meta-analysis.ParticipantsHospitalised adults.InterventionPrevention methods included staff and patient education, environmental modifications, assistive devices, policies and systems, rehabilitation, medication management and management of cognitive impairment. We evaluated single and multi-factorial approaches.Outcome measuresFalls rate ratios (rate ratio: RaR) and falls risk, as defined by the odds of being a faller in the intervention compared to control group (odds ratio: OR).ResultsThere were 43 studies that satisfied the systematic review criteria and 23 were included in meta-analyses. There was marked heterogeneity in intervention methods and study designs. The only intervention that yielded a significant result in the meta-analysis was education, with a reduction in falls rates (RaR = 0.70 [0.51–0.96], P = 0.03) and the odds of falling (OR = 0.62 [0.47–0.83], P = 0.001). The patient and staff education studies in the meta-analysis were of high quality on the GRADE tool. Individual trials in the systematic review showed evidence for clinician education, some multi-factorial interventions, select rehabilitation therapies, and systems, with low to moderate risk of bias.ConclusionPatient and staff education can reduce hospital falls. Multi-factorial interventions had a tendency towards producing a positive impact. Chair alarms, bed alarms, wearable sensors and use of scored risk assessment tools were not associated with significant fall reductions.
Erectile dysfunction predicts mortality in middle-aged and older men independent of their sex steroid status
Authors: Antonio Leen , Wu Frederick C W , Moors Hannes , Matheï Cathy , Huhtaniemi Ilpo T , Rastrelli Giulia , Dejaeger Marian , O’Neill Terence W , Pye Stephen R , Forti Gianni , Maggi Mario , Casanueva Felipe F , Slowikowska-Hilczer Jolanta , Punab Margus , Tournoy Jos , Vanderschueren Dirk ,   the EMAS Study Group, Forti Gianni , Petrone Luisa , Corona Giovanni , Rastrelli Giulia , Maggi (Florence) Mario , Vanderschueren Dirk , Tournoy Jos , Borghs Herman , Antonio (Leuven) Leen , Kula Krzysztof , Slowikowska-Hilczer Jolanta , Walczak-Jedrzejowska (Łódz) Renata , Huhtaniemi (London) Ilpo , Giwercman (Malmö) Aleksander , Wu Frederick , Silman Alan , O’Neill Terence , Finn Joseph , Pye (Manchester) Stephen , Casanueva Felipe , Crujeiras (Santiago) Ana B , Bartfai Gyorgy , Földesi Imre , Fejes (Szeged) Imre , Punab Margus , Korrovitz (Tartu) Paul 
Published: April 2022

Abstract

Background
erectile dysfunction is associated with mortality, whereas the association between low testosterone (T) and higher mortality remains controversial. Sexual dysfunction and low T often coexist, but the relative importance of sexual symptoms versus low T in predicting mortality is not known. We studied the interrelationships between sex steroids and sexual symptoms with all-cause mortality in a large prospective cohort of European men.

Design
survival status was assessed in 1,788 community-dwelling men, aged 40–79, who participated in the European Male Ageing Study (EMAS). Sexual symptoms were evaluated via a validated questionnaire (EMAS-SFQ). Sex steroids were measured by mass spectrometry. Cox proportional hazard models were used to study the association between hormones, sexual symptoms and mortality.

Results
about 420 (25.3%) men died during a mean follow-up of 12.6 ± 3.1 years. Total T levels were similar in both groups, but free T was lower in those who died. Men with three sexual symptoms (erectile dysfunction, reduced morning erections and lower libido) had a higher mortality risk compared with men with none of these symptoms (adjusted hazard ratio (HR) and 95% confidence intervals: 1.75 (1.28–2.40, P = 0.001)). Particularly, erectile dysfunction and poor morning erections, but not lower libido, were associated with increased mortality (HR 1.40 (1.13–1.74, P = 0.002), 1.28 (1.04–1.59, P = 0.023) and 1.12 (0.90–1.39, P = 0.312), respectively). Further adjusting for total T, free T or oestradiol did not influence the observed risk.

Conclusions
sexual symptoms, in particular erectile dysfunction, predict all-cause mortality independently of sex steroids and can be an early warning sign of a poor health status.