bluuebunny/crossref_metadata_2025_split huggingface dataset:
Onsager coefficients in a coupled-transport model displaying a condensation transition
Authors: Iubini Stefano , Politi Antonio , Politi Paolo 
Published: June 2023

Abstract
We study nonequilibrium steady states of a one-dimensional stochastic model, originally introduced as an approximation of the discrete nonlinear Schrödinger equation. This model is characterized by two conserved quantities, namely mass and energy; it displays a ‘normal’, homogeneous phase, separated by a condensed (negative-temperature) phase, where a macroscopic fraction of energy is localized on a single lattice site. When steadily maintained out of equilibrium by external reservoirs, the system exhibits coupled transport herein studied within the framework of linear response theory. We find that the Onsager coefficients satisfy an exact scaling relationship, which allows reducing their dependence on the thermodynamic variables to that on the energy density for unitary mass density. We also determine the structure of the nonequilibrium steady states in proximity of the critical line, proving the existence of paths which partially enter the condensed region. This phenomenon is a consequence of the Joule effect: the temperature increase induced by the mass current is so strong as to drive the system to negative temperatures. Finally, since the model attains a diverging temperature at finite energy, in such a limit the energy–mass conversion efficiency reaches the ideal Carnot value.
Theoretical investigation of substitutionally doped symmetrical finite phenine nanotubes
Authors: Sharma Amrish , Sharma Hitesh , Mudahar Isha 
Published: June 2023

Abstract
Ab initio density functional theory calculations were performed to investigate the substitutional doping of boron and nitrogen in symmetrical phenine nanotubes. It was found that the doped structures are energetically favorable and can be grown experimentally. Furthermore, we investigated how electronic and magnetic properties of these nanotubes change in the presence of electron-rich (nitrogen) and electron-deficient (boron) impurities, and found that doping in these tubes resulted in a non-magnetic structure. The doping changes the electronic structure of the tube by reducing the energy gap and the reduction value is sensitive to the nanotube diameter and impurity type. The gap corresponding to the nitrogen doped tubes is in the range of 2.38 eV-2.64 eV, whereas for boron doped tubes, the value lies in 1.91 eV to 2.11 eV, respectively. Moreover, the nitrogen doped phenine nanotubes tend to be n-type semi-conductor. The doped phenine nanotube molecules with a high stability and tunable electronic properties may offer several interesting applications in nano-electronics.
A new 3D hidden conservative chaotic system with multistability and its circuit implementation
Authors: Wang Qiao , Hu Chenyang , Tian Zean , Wu Xianming , Sang Haiwei 
Published: June 2023

Abstract
A novel three-dimensional conservative system without an equilibrium point is constructed by replacing the square term x
2 + y
2 in the Vaidyanathan - Sundarapandian oscillator with a simple absolute value term |x|. The system is analyzed in detail by using time-domain waveform plots, bifurcation plots, Lyapunov exponent spectra, spectral entropy (SE), and C0 complexity. It is found that the system has rich dynamic behaviors: multiple phase trajectories can be tuned by only one parameter and multistability due to initial value sensitivity. The system shows that it can yield eight heterogeneous trajectories coexistent at different initial conditions, including periodic, quasi-periodic, and chaotic states. Additionally, the transient behavior was also observed. Finally, the experimental circuit was implemented, verifying both the physical realizability and the rich dynamic behaviors of the proposed system. With high complexity and sensitivity of parameter and initial condition, the proposed system is useful in image encryption and secure communication.
Stability and observability of magnetic primordial black hole-neutron star collisions
Authors: Estes John , Kavic Michael , Liebling Steven L. , Lippert Matthew , Simonetti John H. 
Published: June 2023

Abstract
The collision of a primordial black hole with a neutron star results in the black hole eventually consuming the entire neutron star. However, if the black hole is magnetically charged, and therefore stable against decay by Hawking radiation, the consequences can be quite different. Upon colliding with a neutron star, a magnetic black hole very rapidly comes to a stop. For large enough magnetic charge, we show that this collision can be detected as a sudden change in the rotation period of the neutron star, a glitch or anti-glitch.We argue that the magnetic primordial black hole, which then settles to the core of the neutron star, does not necessarily devour the entire neutron star; the system can instead reach a long-lived, quasi-stable equilibrium. Because the black hole is microscopic compared to the neutron star, most stellar properties remain unchanged compared to before the collision. However, the neutron star will heat up and its surface magnetic field could potentially change, both effects potentially observable.
Probing sterile neutrino dark matter in the PTOLEMY-like experiment
Authors: Choi Ki-Young , Lkhagvadorj Erdenebulgan , Yoo Seong Moon 
Published: June 2023

Abstract
We study the prospect to detect the cosmic background of sterile neutrinos in the tritium β-decay, such as the PTOLEMY-like experiments. The sterile neutrino with mass between 1 eV–10 keV may contribute to the local density as warm or cold dark matter component. In this study, we investigate the possibility for searching them in the models with different production in the early Universe, without assuming sterile neutrino as full dark matter component.
In these models, especially with low-reheating temperature and late-time phase transition, the capture rate per year can be greatly enhanced to be 𝒪(10) around the mass range 10–100 eV without violating other astrophysical and cosmological observations.
Study on Attitude Deviation of Spacecraft Subjected to Random Disturbance Torque based on Covariance Analysis
Authors: Obama Biyogo Nchama Vicente Angel , Shi Peng , Saeed Ayesha , Hassen Ahmed Yimam , Sanusi Babansoro Muhammad 
Published: June 2023

Abstract
The attitude stability requirements of spacecraft are closely related to their application scenarios. Spacecraft’s motion will always be affected by internal and external disturbances during its orbital movement, which makes the attitude no longer meet the stability requirements of the mission design convention. This paper focuses on the study of the effect of random disturbance torques on the spacecraft attitude. The basic covariance method is proposed to study the influence of random disturbance torques on the spacecraft attitude. The simulation results show that the method of covariance analysis can be applied to study the attitude deviation of spacecraft due to random disturbances.
Fixed-time Disturbance Observer-Based Finite-Time Backstepping Control for Hypersonic Vehicle
Authors: Zhang Bangchu , Rao Shuitao , Kuang Yu , Bai Zhuo , Zhu Weiyu 
Published: June 2023

Abstract
Due to the severe flight environment, hypersonic vehicles are susceptible to external disturbances and aerodynamic parameter uncertainties, dramatically challenging the precise control and stable tracking. This paper presented a fixed-time disturbance observer (FTDO) to obtain better tracking performance for hypersonic vehicles. The FTDO can improve the tracking performance under external disturbances and aerodynamic parameter perturbations, whose observation time is bounded and does not depend on the initial errors. The backstepping control can guarantee finite-time convergence with the finite-time control technique. A second-order filter is designed to process the complexity explosion problem in the traditional backstepping control and ensure the tracking system’s finite-time stability. Then with Lyapunov theory, it is proved that the control system is stable and convergent in finite time. Finally, three numerical simulation results based on typical conditions are given to show the effectiveness and advantage of the developed control scheme, and external disturbances can be estimated accurately within two seconds. These results have reference value for flight controller design of hypersonic and other aircraft in complex disturbance environments.
Impact of the gas choice and the geometry on the breakdown limits in Micromegas detectors
Authors: Gasik P. , Waldmann T. , Fabbietti L. , Klemenz T. , Lautner L. , Ulukutlu B. 
Published: June 2023

Abstract
In this study we investigate the stability limits of Micromegas detectors upon irradiation
with alpha particles. The results are obtained with meshes with different optical transparency and
geometry of wires. The measurements are performed in Ar- and Ne- based mixtures with different
CO2 content. We observe that the breakdown limit strongly depends on the gas and that a higher
amount of quencher in the mixture does not necessarily correlate with higher stability. In
addition, we observe discharge probability scaling with the wire pitch. This suggests that a
Micromegas mesh cell can be treated as an independent amplification unit, similar to a hole in a
GEM foil. The outcome of these studies provides valuable input for further optimization of MPGD
detectors, multi-layer stacks in particular.
Studying the impact of humidity on the performance of THGEMs
Authors: Fribert H. , Gasik P. , Ulukutlu B. , Fabbietti L. 
Published: June 2023

Abstract
In this study, we investigate the impact of humidity on the performance of a THGEM
operated with an Ar-CO2 gas mixture. The water content is introduced in a range of
0–4000 ppmV. It is observed that the presence of increased humidity does not degrade any of the
studied performance criteria. On the contrary, our measurements suggest an improvement in
discharge stability with increasing humidity levels at the highest gains and fields. No
significant difference is observed at the lower gains, indicating that humidity helps to avoid
spurious discharges related to electrode defects or charging-up of the insulating layers. We
conclude that adding a small amount of water to the gas mixture may be beneficial for the stable
operation of an MPGD.
Network of chiral one-dimensional channels and localized states emerging in a moiré system
Authors: Park Jeyong , Gresista Lasse , Trebst Simon , Rosch Achim , Park Jinhong 
Published: June 2023

AbstractMoiré systems provide a highly tunable platform for engineering band structures and exotic correlated phases. Here, we theoretically study a model for a single layer of graphene subject to a smooth moiré electrostatic potential, induced by an insulating substrate layer. For sufficiently large moiré unit cells, we find that ultra-flat bands coexist with a triangular network of chiral one-dimensional (1D) channels. These channels mediate an effective interaction between localized modes with spin-, orbital- and valley degrees of freedom emerging from the flat bands. The form of the interaction reflects the chirality and 1D nature of the network. We study this interacting model within anSU(4) mean-field theory, semi-classical Monte-Carlo simulations, and anSU(4) spin-wave theory, focusing on commensurate order stabilized by local two-site and chiral three-site interactions. By tuning a gate voltage, one can trigger a non-coplanar phase characterized by a peculiar coexistence of three different types of order: ferromagnetic spin order in one valley, non-coplanar chiral spin order in the other valley, and 120∘order in the remaining spin and valley-mixed degrees of freedom. Quantum and classical fluctuations have qualitatively different effects on the observed phases and can, for example, create a finite spin-chirality purely via fluctuation effects.
Active learning on a programmable photonic quantum processor
Authors: Ding Chen , Xu Xiao-Yue , Niu Yun-Fei , Zhang Shuo , Huang He-Liang , Bao Wan-Su 
Published: June 2023

Abstract
Training a quantum machine learning model generally requires a large labeled dataset, which incurs high labeling and computational costs. To reduce such costs, a selective training strategy, called active learning (AL), chooses only a subset of the original dataset to learn while maintaining the trained model’s performance. Here, we design and implement two AL-enpowered variational quantum classifiers to investigate the potential applications and effectiveness of AL in quantum machine learning. Firstly, we build a programmable free-space photonic quantum processor, which enables the programmed implementation of various hybrid quantum-classical computing algorithms. Then, we code the designed variational quantum classifier with AL into the quantum processor, and execute comparative tests for the classifiers with and without the AL strategy. The results validate the great advantage of AL in quantum machine learning, as it saves at most

85
%

labeling efforts and

91.6
%

percent computational efforts compared to the training without AL on a data classification task. Our results inspire AL’s further applications in large-scale quantum machine learning to drastically reduce training data and speed up training, underpinning the exploration of practical quantum advantages in quantum physics or real-world applications.
Relativistic probability densities for location
Authors: Fenwick Joshua G , Dick Rainer 
Published: June 2023

Abstract
Imposing the Born rule as a fundamental principle of quantum mechanics would require the existence of normalizable wave functions ψ(
x
, t) also for relativistic particles. Indeed, the Fourier transforms of normalized
k
-space amplitudes

ψ
(
k
,
t
)
=
ψ
(
k
)
exp
(
−
i

ω

k

t
)

yield normalized functions ψ(
x
, t) which reproduce the standard
k
-space expectation values for energy and momentum from local momentum (pseudo-)densities ℘
μ
(
x
, t) = (ℏ/2i)[ψ
+(
x
, t)∂
μ

ψ(
x
, t) − ∂
μ

ψ
+(
x
, t) · ψ(
x
, t)]. However, in the case of bosonic fields, the wave packets ψ(
x
, t) are nonlocally related to the corresponding relativistic quantum fields ϕ(
x
, t), and therefore the canonical local energy-momentum densities


(
x
,
t
)
=
c



0

(
x
,
t
)

and


(
x
,
t
)

differ from ℘
μ
(
x
, t) and appear nonlocal in terms of the wave packets ψ(
x
, t). We examine the relation between the canonical energy density


(
x
,
t
)

, the canonical charge density ϱ(
x
, t), the energy pseudo-density



˜

(
x
,
t
)
=
c

℘

0

(
x
,
t
)

, and the Born density ∣ψ(
x
, t)∣2 for the massless free Klein–Gordon field. We find that those four proxies for particle location are tantalizingly close even in this extremely relativistic case: in spite of their nonlocal mathematical relations, they are mutually local in the sense that their maxima do not deviate beyond a common position uncertainty Δx. Indeed, they are practically indistinguishable in cases where we would expect a normalized quantum state to produce particle-like position signals, viz. if we are observing quanta with momenta p ≫ Δp ≥ ℏ/2Δx. We also translate our results to massless Dirac fields. Our results confirm and illustrate that the normalized energy density


(
x
,
t
)

/

E

provides a suitable measure for positions of bosons, whereas normalized charge density ϱ(
x
, t)/q provides a suitable measure for fermions.
Investigating the impact of working arrangements and lifestyle factor importance on environmental consciousness
Authors: Chapman Andrew , Karmaker Shamal Chandra , Shigetomi Yosuke 
Published: June 2023

Abstract
This study investigates the impact of people’s demographics, preferred working arrangements and utilization of their free time on environmental consciousness. Such an investigation is timely because of the changing expectations around working, and the rising popularity of work-from-home arrangements leading to increased flexibility. Although the link between income and environmental impact is well understood, the mediating factors between working arrangements and environmental concerns remain unclear. Through the analysis of a nationally representative survey conducted in Japan, we clarify people’s desire to work shorter hours, subject to the maintenance of income levels, along with a desire to consider revised working arrangements if environmental improvements can be anticipated as a result. One important finding of this research is that those who prioritize their free time for family and friends have a much higher probability of valuing the environment and thus reducing their carbon footprint. These findings have implications for policy design which encourages low impact working arrangements, the sharing economy and a family friendly society.
Absence of infective endocarditis relapse when end-of-treatment fluorodeoxyglucose positron emission tomography/computed tomography is negative
Authors: Régis Claudine , Thy Michael , Mahida Besma , Deconinck Laurène , Tubiana Sarah , Iung Bernard , Duval Xavier , Rouzet François 
Published: June 2023

Abstract

Aims
In non-operated infective endocarditis (IE), relapse may impair the outcome of the disease. The aim of the study was to evaluate the relationship between end-of-treatment (EOT) fluorodeoxyglucose positron emission tomography/computed tomography FDG-PET/CT results and relapse in non-operated IE either on native or prosthetic valve.

Methods and results
We included 62 patients who underwent an EOT FDG-PET/CT for non-operated IE performed between 30 and 180 days of antibiotic therapy initiation. Qualitative valve assessment categorized initial and EOT FDG-PET/CT as negative or positive. Quantitative analyses were also conducted. Clinical data from medical charts were collected, including endocarditis team decision for IE diagnosis and relapse. Forty-one (66%) patients were male with a median age of 68 years (57; 80) and 42 (68%) had prosthetic valve IE. End-of-treatment FDG-PET/CT was negative in 29 and positive in 33 patients. The proportion of positive scans decreased significantly compared with initial FDG-PET/CT (53% vs. 77%, respectively, P &lt; 0.0001). All relapses (n = 7, 11%) occurred in patients with a positive EOT FDG-PET/CT with a median delay after EOT FDG-PET/CT of 10 days (0; 45). The relapse rate was significantly lower in negative (0/29) than in positive (7/33) EOT FDG-PET/CT (P = 0.01).

Conclusion
In this series of 62 patients with non-operated IE who underwent EOT FDG-PET/CT, those with a negative scan (almost half of the study population) did not develop IE relapse after a median follow-up of 10 months. These findings need to be confirmed by prospective and larger studies.
Pharmacological properties and derivatives of saikosaponins—a review of recent studies
Authors: Zhu Yingchao , Lai Yu 
Published: June 2023

Abstract

Objectives
Saikosaponins (SSs) constitute a class of medicinal monomers characterised by a triterpene tricyclic structure. Despite their potential therapeutic effects for various pathological conditions, the underlying mechanisms of their actions have not been systematically analysed. Here, we mainly review the important anti-inflammatory, anticancer, and antiviral mechanisms underlying SS actions.

Methods
Information from multiple scientific databases, such as PubMed, the Web of Science, and Google Scholar, was collected between 2018 and 2023. The search term used was saikosaponin.

Key findings
Numerous studies have shown that Saikosaponin A exerts anti-inflammatory effects by modulating cytokine and reactive oxygen species (ROS) production and lipid metabolism. Moreover, saikosaponin D exerts antitumor effects by inhibiting cell proliferation and inducing apoptosis and autophagy, and the antiviral mechanisms of SSs, especially against SARS-CoV-2, have been partially revealed. Interestingly, an increasing body of experimental evidence suggests that SSs show the potential for use as anti-addiction, anxiolytic, and antidepressant treatments, and therefore, the related molecular mechanisms warrant further study.

Conclusions
An increasing amount of data have indicated diverse SS pharmacological properties, indicating crucial clues for future studies and the production of novel saikosaponin-based anti-inflammatory, efficacious anticancer, and anti-novel-coronavirus agents with improved efficacy and reduced toxicity.
Clinical impact of radiation-induced myocardial damage detected by cardiac magnetic resonance imaging and dose-volume histogram parameters of the left ventricle as prognostic factors of cardiac events after chemoradiotherapy for esophageal cancer
Authors: Umezawa Rei , Ota Hideki , Takagi Hidenobu , Kadoya Noriyuki , Nakajima Yujiro , Takahashi Noriyoshi , Yamamoto Takaya , Takase Kei , Jingu Keiichi 
Published: June 2023

Abstract
This prospective study aimed to evaluate whether radiation (RT)-induced myocardial damage by cardiac magnetic resonance (CMR) imaging could be a predictor of cardiac events after chemoradiotherapy (CRT) for esophageal cancer and determine the dose-volume histogram (DVH) parameters of the left ventricle (LV) in predicting cardiac events. CMR imaging was performed before and 6 months after CRT in patients receiving definitive CRT. RT-induced myocardial damage was defined as abnormal CMR findings indicating myocardial fibrosis corresponding to an isodose line of ≥30 Gy. The cutoff values of the LV DVH parameters were calculated using the receiver operating characteristic curve based on the presence of RT-induced myocardial damage. The prognostic factors related to cardiac events of Grade 3 or higher were examined. Twenty-three patients were enrolled in the study. RT-induced myocardial damage by late gadolinium enhancement and/or an increase of 100 ms or higher in native T1 post-CRT was detected in 10 of the 23 patients. LV V45 was the best predictive factor for RT-induced myocardial damage with a cutoff value of 2.1% and an area under the curve of 0.75. The median follow-up period was 82.1 months. The 5- and 7-year cumulative incidences of cardiac events of Grade 3 or higher were 14.7 and 22.4%, respectively. RT-induced myocardial damage and LV V45 were significant risk factors (P = 0.015 and P = 0.013, respectively). RT-induced myocardial damage is a significant predictor of cardiac events. LV V45 is associated with RT-induced myocardial damage and subsequent cardiac events.