bluuebunny/crossref_metadata_2025_split huggingface dataset:
A vibration correction system for cold atom gravimeter
Authors: Guo Meiying , Bai Jinhai , Hu Dong , Tang Zhimin , You Jianqi , Chen Runnan , Wang Yu 
Published: December 2023

Abstract
Cold atom gravimeters are used to measure the absolute value of the gravitational acceleration. To mitigate the influence of seismic noise on the mirror, a vibration correction system is used. A commercial seismometer CMG-3ESPC is employed to measure the mirror vibration. The transfer function between the mirror vibration and the output of the seismometer is regarded as a proportional element with a time delay. The best proportional element and the best time delay are obtained by minimizing the standard deviation of the fitting residuals of the interference fringe

α
−
P

with vibration correction. This system not only exhibits excellent environmental adaptability but also eliminates the need for rough estimation of local gravitational acceleration during the vibration correction process. The system was built on the homemade cold atom gravimeter to carry out experiments in the laboratory. Compared with the measurement results without vibration correction, the standard deviation of the gravity measurement results was reduced from

120.5
μ

Gal to

4.2
μ

Gal, resulting in a significant reduction by a factor of 28.7. Meanwhile, its sensitivity was significantly improved from 330.8

μ

Gal

Hz

−
1

to 18.0

μ

Gal

Hz

−
1

by performing vibration correction. In the future, this system is expected to carry out comprehensive verification experiments in more complex noisy environments.
Well–posedness of the three–dimensional NLS equation with sphere–concentrated nonlinearity
Authors: Finco Domenico , Tentarelli Lorenzo , Teta Alessandro 
Published: December 2023

Abstract
We discuss strong local and global well–posedness for the three–dimensional NLS equation with nonlinearity concentrated on

S

2

. Precisely, local well–posedness is proved for any C
2 power–nonlinearity, while global well–posedness is obtained either for small data or in the defocusing case under some growth assumptions. With respect to point–concentrated NLS models, widely studied in the literature, here the dimension of the support of the nonlinearity does not allow a direct extension of the known techniques and calls for new ideas.
Canonical curves and Kropina metrics in Lagrangian contact geometry
Authors: Ma Tianyu , Flood Keegan J , Matveev Vladimir S , Žádník Vojtěch 
Published: December 2023

AbstractWe present a Fefferman-type construction from Lagrangian contact to split-signature conformal structures and examine several related topics. In particular, we describe the canonical curves and their correspondence. We show that chains and null-chains of an integrable Lagrangian contact structure are the projections of null-geodesics of the Fefferman space. Employing the Fermat principle, we realize chains as geodesics of Kropina (pseudo-Finsler) metrics. Using recent rigidity results, we show that ‘sufficiently many’ chains determine the Lagrangian contact structure. Separately, we comment on Lagrangian contact structures induced by projective structures and the special case of dimension three.
Symmetric periodic orbits in symmetric billiards
Authors: Ferreira Geraldo César Gonçalves , Oliffson Kamphorst Sylvie , Pinto-de-Carvalho Sônia 
Published: December 2023

Abstract
In this text we study billiards on symmetric ovals and investigate some consequences of the symmetry of the boundary on the dynamics. As it simplifies some calculations, the symmetry helps to obtain the results. We focus on periodic orbits with the same symmetry of the boundary which always exist and prove that typically half of them are elliptic and Moser stable and the other half are hyperbolic with homo(hetero)clinic intersections.
Spectrality of random convolutions generated by finitely many Hadamard triples
Authors: Li Wenxia , Miao Jun Jie , Wang Zhiqiang 
Published: December 2023

Abstract
Let

{
(

N
j

,

B
j

,

L
j

)
:
1
⩽
j
⩽
m
}

be finitely many Hadamard triples in

R

. Given a sequence of positive integers

{

n
k

}

k
=
1

∞

and

ω
=
(

ω
k

)

k
=
1

∞

∈
{
1
,
2
,
…
,
m

}

N

, let

μ

ω
,
{

n
k

}

be the infinite convolution given by

μ

ω
,

n
k

=

δ

N

ω
1

−

n
1

B

ω
1

∗

δ

N

ω
1

−

n
1

N

ω
2

−

n
2

B

ω
2

∗
⋯
∗

δ

N

ω
1

−

n
1

N

ω
2

−

n
2

⋯

N

ω
k

−

n
k

B

ω
k

∗
⋯
.

In order to study the spectrality of

μ

ω
,
{

n
k

}

, we first show the spectrality of general infinite convolutions generated by Hadamard triples under the equi-positivity condition. Then by using the integral periodic zero set of Fourier transform we show that if

g
c
d

(

B
j

−

B
j

)
=
1

for

1
⩽
j
⩽
m

, then all infinite convolutions

μ

ω
,
{

n
k

}

are spectral measures. This implies that we may find a subset

Λ

ω
,
{

n
k

}

⊆

R

such that

{

e
λ

(
x
)
=

e

2
π
i
λ
x

:
λ
∈

Λ

ω
,
{

n
k

}

}

forms an orthonormal basis for

L
2

(

μ

ω
,
{

n
k

}

)

.
An in-reachability based classification of invariant synchrony patterns in weighted coupled cell networks
Authors: Sequeira P M , Hespanha J P , Aguiar A P 
Published: December 2023

Abstract
This paper presents an in-reachability based classification of invariant synchrony patterns in coupled cell networks (CCNs). These patterns are encoded through partitions on the set of cells, whose subsets of synchronised cells are called colours. We study the influence of the structure of the network in the qualitative behaviour of invariant synchrony sets, in particular, with respect to the different types of (cumulative) in-neighbourhoods and the in-reachability sets. This motivates the proposed approach to classify the partitions into the categories of strong, rooted and weak, according to how their colours are related with respect to the connectivity structure of the network. Furthermore, we show how this classification system acts under the partition join (

∨

) operation, which gives us the synchrony pattern that corresponds to the intersection of synchrony sets.
Discriminative fusion of moments-aligned latent representation of multimodality medical data
Authors: Xie Jincheng , Zhong Weixiong , Yang Ruimeng , Wang Linjing , Zhen Xin 
Published: December 2023

Abstract
Fusion of multimodal medical data provides multifaceted, disease-relevant information for diagnosis or prognosis prediction modeling. Traditional fusion strategies such as feature concatenation often fail to learn hidden complementary and discriminative manifestations from high-dimensional multimodal data. To this end, we proposed a methodology for the integration of multimodality medical data by matching their moments in a latent space, where the hidden, shared information of multimodal data is gradually learned by optimization with multiple feature collinearity and correlation constrains. We first obtained the multimodal hidden representations by learning mappings between the original domain and shared latent space. Within this shared space, we utilized several relational regularizations, including data attribute preservation, feature collinearity and feature-task correlation, to encourage learning of the underlying associations inherent in multimodal data. The fused multimodal latent features were finally fed to a logistic regression classifier for diagnostic prediction. Extensive evaluations on three independent clinical datasets have demonstrated the effectiveness of the proposed method in fusing multimodal data for medical prediction modeling.
Evaluation of monte carlo to support commissioning of the treatment planning system of new pencil beam scanning proton therapy facilities
Authors: Botnariuc D , Court S , Lourenço A , Gosling A , Royle G , Hussein M , Rompokos V , Veiga C 
Published: December 2023

ABSTRACT

Objective. To demonstrate the potential of Monte Carlo (MC) to support the resource-intensive measurements that comprise the commissioning of the treatment planning system (TPS) of new proton therapy facilities. Approach. Beam models of a pencil beam scanning system (Varian ProBeam) were developed in GATE (v8.2), Eclipse proton convolution superposition algorithm (v16.1, Varian Medical Systems) and RayStation MC (v12.0.100.0, RaySearch Laboratories), using the beam commissioning data. All models were first benchmarked against the same commissioning data and validated on seven spread-out Bragg peak (SOBP) plans. Then, we explored the use of MC to optimise dose calculation parameters, fully understand the performance and limitations of TPS in homogeneous fields and support the development of patient-specific quality assurance (PSQA) processes. We compared the dose calculations of the TPSs against measurements (DDTPSvs.Meas.) or GATE (DDTPSvs.GATE) for an extensive set of plans of varying complexity. This included homogeneous plans with varying field-size, range, width, and range-shifters (RSs) (n = 46) and PSQA plans for different anatomical sites (n = 11). Main results. The three beam models showed good agreement against the commissioning data, and dose differences of 3.5% and 5% were found for SOBP plans without and with RSs, respectively. DDTPSvs.Meas. and DDTPSvs.GATE were correlated in most scenarios. In homogeneous fields the Pearson’s correlation coefficient was 0.92 and 0.68 for Eclipse and RayStation, respectively. The standard deviation of the differences between GATE and measurements (±0.5% for homogeneous and ±0.8% for PSQA plans) was applied as tolerance when comparing TPSs with GATE. 72% and 60% of the plans were within the GATE predicted dose difference for both TPSs, for homogeneous and PSQA cases, respectively. Significance. Developing and validating a MC beam model early on into the commissioning of new proton therapy facilities can support the validation of the TPS and facilitate comprehensive investigation of its capabilities and limitations.
Structural approach to charge density waves in low-dimensional systems: electronic instability and chemical bonding
Authors: Pouget Jean-Paul , Canadell Enric 
Published: December 2023

Abstract
The charge density wave (CDW) instability, usually occurring in low-dimensional metals, has been a topic of interest for longtime. However, some very fundamental aspects of the mechanism remain unclear. Recently, a plethora of new CDW materials, a substantial fraction of which is two-dimensional or even three-dimensional, has been prepared and characterised as bulk and/or single-layers. As a result, the need for revisiting the primary mechanism of the instability, based on the electron–hole instability established more than 50 years ago for quasi-one-dimensional (quasi-1D) conductors, has clearly emerged. In this work, we consider a large number of CDW materials to revisit the main concepts used in understanding the CDW instability, and emphasise the key role of the momentum dependent electron–phonon coupling in linking electronic and structural degrees of freedom. We argue that for quasi-1D systems, earlier weak coupling theories work appropriately and the energy gain due to the CDW and the concomitant periodic lattice distortion (PLD) remains primarily due to a Fermi surface nesting mechanism. However, for materials with higher dimensionality, intermediate and strong coupling regimes are generally at work and the modification of the chemical bonding network by the PLD is at the heart of the instability. We emphasise the need for a microscopic approach blending condensed matter physics concepts and state-of-the-art first-principles calculations with quite fundamental chemical bonding ideas in understanding the CDW phenomenon in these materials.
Existence of complex magnetic ground state and topological Hall effect in centrosymmetric silicide DyScSi
Authors: Yadav Kavita , P Koushik , Singh Saurabh , Hagihala Masato , Mukherjee K 
Published: December 2023

Abstract
Topological Hall effect (THE) originating from non-trivial spin arrangements in magnetic materials has been extensively investigated in recent years. In this context, a centrosymmetric ternary silicide, DyScSi, is explored. Here we show that, a complex magnetic ground state drives THE in a centrosymmetric system. Temperature dependent magnetisation and neutron diffraction results establish the presence of commensurate antiferromagnetic (AFM) phase around 92 K, followed by an incommensurate AFM phase below 40 K. Additionally, two cluster glass transitions near 20 and 8 K, are also noted. These observed features arise due competing AFM and FM interactions. In conjunction with this, a finite contribution of THE is also observed in the intermediate field regime (8–30 kOe), at low temperature in DyScSi. The behaviour of this silicide appears to be fascinating in terms of interplay between complex magnetic ground state and THE in centrosymmetric structure.
Excitation of wakefields in carbon nanotubes: a hydrodynamic model approach
Authors: Martín-Luna P , Bonatto A , Bontoiu C , Xia G , Resta-López J 
Published: December 2023

Abstract
The interactions of charged particles with carbon nanotubes (CNTs) may excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell constituting the nanotube wall. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of these wakefields is studied by means of the linearized hydrodynamic model. In this model, the electronic excitations on the nanotube surface are described treating the electron gas as a 2D plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. General expressions are derived for the excited longitudinal and transverse wakefields. Numerical results are obtained for a charged particle moving within a CNT, paraxially to its axis, showing how the wakefield is affected by parameters such as the particle velocity and its radial position, the nanotube radius, and a friction factor, which can be used as a phenomenological parameter to describe effects from the ionic lattice. Assuming a particle driver propagating on axis at a given velocity, optimal parameters were obtained to maximize the longitudinal wakefield amplitude.
Design of S-box multi-objective optimization algorithm based on combined chaotic system
Authors: Tong Xiaojun , Cheng Liming , Wang Zhu , Zhang Miao 
Published: December 2023

Abstract
S-box is the only nonlinear cryptographic component that determines the security of the block cipher. The higher the security of the S-box, the higher the security of the block cipher. Therefore, this paper proposes an S-box multi-objective optimization algorithm based on the combined chaotic system. Firstly, designing an integrated chaotic system based on a fractional index and its dynamic behavior is studied; it shows incredibly high-performance stability and chaotic parameter range coverage in the entire parameter space. A novel chaotic S-box construction algorithm is proposed based on the combined chaotic system. It introduces a linear congruential pseudo-random number generator to extend the sequence period and scramble the chaotic S-box through Henon mapping to improve the nonlinearity of the s-box. Finally, introducing a teaching and learning multi-objective optimization model and the performance evaluation criteria of the S-box are incorporated into the design of the objective function; this design enables the resulting S-box to perform well under multiple performance indicators, and then the approximate optimal S-box in the population is obtained. Through the performance test of the approximate optimal S-box, the comparative analysis shows that the S-box has good cryptographic performance, can resist linear analysis and differential analysis, and has a good application prospect in lightweight cipher.
Temperature and volume dependence of pion-pion scattering lengths*
Authors: Wang 王 Qing-Wu 庆武 , Guo 郭 Hua-Zhong 华忠 
Published: December 2023

Abstract
The s-wave pion-pion scattering lengths

and

are studied at finite temperature and in finite spatial volume under the framework of the Nambu–Jona-Lasinio model. The behavior beyond the pseudo transition temperature is investigated using proper time regularization. The scattering length

exhibits singularity near the Mott temperature, and

is a continuous but non-monotonic function of temperature. We present the effect of finite volume on the scattering length and find that

can be negative and its singularity disappears at small volumes, which may hint at the existence of a chiral phase transition with decreasing volume.
Variable Stars in the 50BiN Open Cluster Survey. III. NGC 884
Authors: Wang Lin-Hong , Nie Qian-Heng , Wang Kun , Chen Xiao-Dian , Zhang Chun-Guang , Deng Li-Cai , Zhang Xiao-Bin , Chen Tian-Lu 
Published: December 2023

Abstract
Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way. Variable stars in open clusters provide a unique way to accurately probe the internal structure, temporal and dynamical evolutionary stages of individual stars and the host cluster. The most powerful tool for such studies is time-domain photometric observations. This paper follows the route of our previous work, concentrating on a photometric search for variable stars in NGC 884. The target cluster is the companion of NGC 869, forming the well-known double cluster system that is gravitationally bound. From the observation run in 2016 November, a total of 9247 B-band CCD images and 8218 V-band CCD images were obtained. We detected a total of 15 stars with variability in visual brightness, including five Be stars, three eclipsing binaries, and seven of unknown types. Two new variable stars were discovered in this work. We also compared the variable star content of NGC 884 with its companion NGC 869.
Impedance of in-air undulator vacuum chamber in HEPS
Authors: Li Jintao , Wang Na , Yue Sen , Tian Saike 
Published: December 2023

Abstract
Undulators with small gap have been widely used in various
light sources all over the world for the demand of high brilliance.
A large number of in-air undulators with small gap will be installed
in the storage ring of the High Energy Photon Source, and become one
of the important impedance contributors. Antechambers are adopted
for the bypass of the synchrotron radiations, as well as to reach
high vacuum in the beam pipe with small aperture. Due to the
asymmetric structure of the vacuum chamber, monopole wakefield in
the transverse planes will be excited by the beam passage. In
addition, photon absorbers will be installed in the vacuum chamber
of the in-air undulators to shield the downstream components, which
will introduce extra resonances in the transverse planes. In this
paper, a series of numerical simulations are performed to
investigate the impedance of the in-air undulator vacuum chamber.
The high order modes generated by the photon absorber and their
mitigations are also investigated.
Development of a high-voltage radio frequency power supply for quadrupole mass spectrometers with a wide dynamic measurement range
Authors: Wang Xinghui , Cheng Yongjun , Chen Lian , Dong Meng , Feng Tianyou , Zhao Lan , Zhang Ruifang 
Published: December 2023

Abstract
The core component of a quadrupole mass spectrometer is the
quadrupole mass filter, serving a crucial role in ion analysis. It
operates by applying two sets of high-voltage, high-frequency
signals with equal amplitude and opposing phases through the radio
frequency power supply, capitalizing on variations in the electric
field and differences in mass-to-charge ratios to separate incoming
ions. This study leverages direct digital frequency synthesis
technology and multi-stage voltage amplification techniques to
design a tailored radio frequency power supply for quadrupole mass
spectrometers with a broad mass range. Practical testing
demonstrates that this power supply generates radio frequency
high-voltage signals with a peak-to-peak voltage ranging from
2.210 V to 4.220 kV at a resonant frequency of 1.240 MHz,
facilitating the separation of ions with distinct m/z values. Furthermore, the radio frequency power supply is integrated
into a Self-developed quadrupole mass spectrometer, enabling an
assessment of the mass range, resolution, stability of the
spectrometer. The results of these assessments confirm that the
developed power supply accommodates scanning of m/z value ions in
the range of 1 to 1067 while maintaining an absolute resolution of
less than m/z = 1 units and an instrument stability of 2.00% over
four hours.and keywords.
Characteristics of population exposure to climate extremes from regional to global 1.5 °C and 2.0 °C warming in CMIP6 models
Authors: Qin Peihua , Xie Zhenghui , Jia Binghao , Sun Shuai 
Published: December 2023

Abstract
The intensities and occurrences of heat extremes are projected to increase in a warmer climate, and relevant policies have been established to address different warming levels. However, how climate extremes change at regional warming levels is not well-known because changes in temperature vary over different regions. This study investigated climate extremes and population exposure to these extremes at regional and global 1.5 °C or 2.0 °C warming over 58 reference regions with 16 Coupled Model Intercomparison Project, 6th phase models. The years of reaching local 1.5 °C or 2.0 °C warming occurred earlier than the timing of global warming over certain land areas, with more than 30 years advance in northern high latitude land areas. Heat extremes are projected to increase in all reference regions under regional and global 1.5 °C or 2.0 °C warming. Moving from regional to global 1.5 °C or 2.0 °C warming, heat extremes were found to increase over most land areas, especially over mid- and high-latitude areas. Population exposure to climate extremes increased over more than half the land regions under regional to global 1.5 °C or 2.0 °C warming. Changes in population exposure to absolute heat extremes were mainly generated by changes in population over about 34 land regions, whereas changes in population exposure to percentile-based heat extremes over more than 40 land regions were mostly due to changes in climate extremes. These results provided references to establish relevant strategies at regional scale to address possible risks related to climate extremes.