bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maximal submergence in dense granular suspensions
Authors: Williams Hollis 
Published: February 2024

Abstract
How far can a person sink downwards in quicksand? Experience would seem to suggest that there is low risk of submerging completely, but it is not easy to demonstrate this because of the complex rheology of granular suspensions. We study several mathematical models for the sinking of a vertical cylinder downwards into quicksand, finding that an approach with a buoyancy equation modified by drag force gives an unphysical answer. We instead argue that our proposed conclusion is supported by considering the dynamics of vibration-induced compactification of liquid-saturated granular suspensions. We compare quicksand with other non-Newtonian fluids, emphasising that in this case the same model does not apply and that the risk of drowning could be much more significant. We finish by suggesting some relevant experiments that can be performed in a classroom setting.
On mathematical problems of two-coefficient inverse problems of ultrasonic tomography
Authors: Goncharsky Alexander V , Romanov Sergey Y , Seryozhnikov Sergey Y 
Published: February 2024

Abstract
This paper proves the theorem of uniqueness for the solution of a coefficient inverse problem for the wave equation in (with two unknown coefficients: speed of sound and absorption. The original nonlinear coefficient inverse problem is reduced to an equivalent system of two uniquely solvable linear integral equations of the first kind with respect to the sound speed and absorption coefficients. Estimates are made, substantiating the multistage method for two unknown coefficients. These estimates show that given sufficiently low frequencies and small inhomogeneities, the residual functional for the nonlinear inverse problem approaches a convex one. This solution method for nonlinear coefficient inverse problems is not linked to the limit approach as frequency tends to zero, but assumes solving the inverse problem using sufficiently low, but not zero, frequencies at the first stage. For small inhomogeneities that are typical, for instance, for medical tasks, carrying out real experiments at such frequencies does not present major difficulties. The capabilities of the method are demonstrated on a model inverse problem with unknown sound speed and absorption coefficients. The method effectively solves the nonlinear problem with parameter values typical for tomographic diagnostics of soft tissues in medicine. A resolution of approximately 2 mm was achieved using an average sounding pulse wavelength of 5 mm.
Bayesian view on the training of invertible residual networks for solving linear inverse problems
*
Authors: Arndt Clemens , Dittmer Sören , Heilenkötter Nick , Iske Meira , Kluth Tobias , Nickel Judith 
Published: February 2024

Abstract
Learning-based methods for inverse problems, adapting to the data’s inherent structure, have become ubiquitous in the last decade. Besides empirical investigations of their often remarkable performance, an increasing number of works address the issue of theoretical guarantees. Recently, Arndt et al (2023 Inverse Problems
39 125018) exploited invertible residual networks (iResNets) to learn provably convergent regularizations given reasonable assumptions. They enforced these guarantees by approximating the linear forward operator with an iResNet. Supervised training on relevant samples introduces data dependency into the approach. An open question in this context is to which extent the data’s inherent structure influences the training outcome, i.e. the learned reconstruction scheme. Here, we address this delicate interplay of training design and data dependency from a Bayesian perspective and shed light on opportunities and limitations. We resolve these limitations by analyzing reconstruction-based training of the inverses of iResNets, where we show that this optimization strategy introduces a level of data-dependency that cannot be achieved by approximation training. We further provide and discuss a series of numerical experiments underpinning and extending the theoretical findings.
A mixture of Si3N4 powder and SiO2 sand as a novel DC arc quenching medium for improvement of the current-limiting performance of a model electric fuse
Authors: Kodama Naoto , Yokomizu Yasunobu , Takenaka Waku 
Published: February 2024

Abstract
A current-limiting and consequent direct current (DC) arc interruption requires an increase in arc resistance

r

a
r
c

for a DC fuse. Flattery silica (SiO2) sand has been used as an arc quenching medium in fuses for decades. However, there are few reports about a novel arc quenching medium which enables more

r

a
r
c

increases compared to flattery SiO2 sand. This paper uniquely selected a novel arc quenching medium based on the following material properties: (1) electrical resistivity and thermal conductivity in the solid phase, (2) the possibility of

r

a
r
c

increasing in the gas phase, (3) the possibility of electrical insulation after re-solidification, and (4) the cost of materials. As a result, we originally selected a powder mixture of silicon-nitride (Si3N4) and flattery SiO2 sand as a promising novel arc quenching medium. Therefore, DC interruption experiments were performed using a Si3N4/flattery SiO2 sand powder mixture under different Si3N4 concentration conditions. As a result of 1000 A DC arc quenching experiments, the utilization of Si3N4 powder with the flattery SiO2 sand successfully increased the arc resistance

r

a
r
c

during the arc quenching process. The increasing Si3N4 concentration exhibited a further increase in

r

a
r
c

during the arc quenching process. As a result of the

r

a
r
c

increase, the arc quenching time was significantly shortened to 30 ms for 30 wt.% Si3N4 conditions from 54 ms for the SiO2 sand conditions. In addition, utilization of Si3N4 powder achieved high insulation resistance over few MΩ after DC arc interruption. The above results clearly indicate that utilization of Si3N4 powder with flattery SiO2 sand can increase the DC interruption performance of the fuse.
Low temperature Raman spectroscopic study of anharmonic and spin-phonon coupled quasi-two dimensional rare earth based francisites
Authors: Manna P , Kanthal S , Das A , Banerjee A , Bandyopadhyay S 
Published: February 2024

Abstract
Mineral francisites Cu3Bi(SeO3)2O2Cl are unique compounds with interesting quasi two-dimensional structure along with fascinating magnetic properties. The magnetic properties can be fine-tuned when non-magnetic Bi is replaced by a suitable rare earth (RE) metal. It is because of the inclusion of additional magnetic sub-centre RE apart from Cu. Temperature dependent Raman spectroscopy measurements in RE based francisites [Cu3RE(SeO3)2O2Cl, shortly RECufr] were performed in the range of 11 K–295 K. Among the three studied RECufr (LaCufr, NdCufr, and DyCufr) compounds, the properties of phonon vibration vary from moderate (in DyCufr) to weak (in LaCufr) spin phonon coupled and the absence of spin phonon coupling (SPC) (i.e. strictly anharmonic in nature) was observed in NdCufr and the reason for this observation has been provided. More specifically, two Raman-active phonons soften below the antiferromagnetic ordering temperature of TN
≈ 39 K in DyCufr compound, indicating the existence of moderate SPC. This trend of phonon vibration is correlated with magnetic properties, particularly field induced metamagnetic transition (MMT). Strong MMT enabled DyCufr develops SPC, while weak MMT enabled NdCufr is unable to develop SPC.
Full-field static and dynamic strain measurement by an inverse conjugate beam method with two-type sensor placement
Authors: Zhang Qingqing , Li Ruixiao , Tian Kang , Gao Qiang 
Published: February 2024

Abstract
This paper presents a novel inverse conjugate beam method (ICBM) to full-field static and dynamic strain measurement using long-gauge fiber Bragg grating (FBG) and vision sensors. By applying reverse analysis of conjugate beam theory, the ICBM establishes a displacement–strain transformation model that effectively explains the correlation between displacement, distributed strain and desired strain. The static and dynamic strain can be reconstructed directly by combining the monitored displacement and strain responses at the displacement monitoring locations. The vision sensor is employed to complement the installed long-gauge strain sensor for monitoring the displacement of the location without a long-gauge sensor. This method helps overcome the difficulty of monitoring the full-bridge strain due to insufficient sensors or inaccessible monitoring positions. At the same time, according to this method, it is necessary to use the displacement from the visual sensor to determine the residual stiffness of each unit as prior information for the ICBM. Both numerical studies and laboratory tests are carried out on a simply supported beam for conceptual verification. The results demonstrate that the proposed ICBM successfully achieves static and dynamic strain response reconstruction at displacement monitoring locations.
Exponential rate of decay of correlations of equilibrium states associated with non-uniformly expanding circle maps
Authors: Garibaldi Eduardo , Inoquio-Renteria Irene 
Published: February 2024

Abstract
In the context of expanding maps of the circle with an indifferent fixed point, understanding the joint behavior of dynamics and pairs of moduli of continuity

(
ω
,
Ω
)

may be a useful element for the development of equilibrium theory. Here we identify a particular feature of modulus Ω (precisely

lim

x
→

0
+

sup

d

Ω
(
d
x
)
/
Ω
(
d
)
=
0

) as a sufficient condition for the system to exhibit exponential decay of correlations with respect to the unique equilibrium state associated with a potential having ω as modulus of continuity. This result is derived from obtaining the spectral gap property for the transfer operator acting on the space of observables with Ω as modulus of continuity, a property that, as is well known, also ensures the Central Limit Theorem. Examples of application of our results include the Manneville–Pomeau family.
Insights into dynamic switching behavior and electric field distribution of depletion-mode GaN HEMT with bonding pad over active layout
Authors: Guo Lijian , Zhou Feng , Xu Weizong , Ren Fangfang , Zhou Dong , Chen Dunjun , Zhang Rong , Zheng Youdou , Lu Hai 
Published: February 2024

Abstract
Bonding pad over active (BPOA) layout, which stacks traditional horizontal structure pad electrodes vertically above the active area, is an area-effective device architecture and packaging-enabled solution for GaN-based high electron mobility transistors (HEMTs). In this work, the dynamic switching and electric field distribution of such layout, as well as associated capacitance–voltage and trapping characteristics, are comprehensively studied on D-mode GaN-on-sapphire HEMT by performing numerical simulations. In terms of different pad electrodes covering the active area, BPOA is composed of various structures such as gate-related and drain-related BPOAs (i.e. G-BPOA and D-BPOA), among which G-BPOA exhibits inferior switching characteristics due to the additional introduction of Miller capacitance that prolongs the device switching, while breakdown voltage of D-BPOA is 400–900 V lower than other BPOA counterparts due to the interplay between D-BPOA and the drain electrode. Furthermore, the effects of trap capture cross section and trap density on switching characteristics are evaluated. These results highlight the differences in electrical characteristics of various structures within the BPOA layout, and provide valuable insights into BPOA device design and performance improvement.
Phenomenological studies on magnetic and mechanical remanence effects in magnetorheological fluids
Authors: Wiener Thomas , Offenzeller Christina , Martetschläger David , Wimmer David , Spirowski Thomas , Jakoby Bernhard 
Published: February 2024

Abstract
Although magnetorheological fluids (MRF) have been used in science and engineering for many decades and several products based on this technology are known, there is still no consistent routine that properly takes into account major effects in the material. The aim of this work is to establish a series of steps, from the preparation of the fluid through the demagnetization routine to the choice of the angular evaluation point, which will allow to achieve stable and reproducible results regarding the material’s response to magnetic fields and mechanical actuation. As a major result of this work, a general demagnetization routine and a method for subsequent reproducible evaluation accounting for the long-term time-dependent behavior of the MRF were identified. Our efforts are aimed at exploring the following targets and questions: how can a stable initial state be ensured? Why is the initial measurement of MRF commonly hardly reproducible? How can reproducible measurements for characterizing the material be obtained? For each of these items, we developed procedures or suggest measures and discuss to what extent they solve the underlying issues and what had to be left for future investigations.
Nanoribbons of large-gap quantum spin Hall insulator: electronic structures and transport properties
Authors: Wu Meimei , Hua Chenqiang , Song Biyu , Zhi Guo-Xiang , Niu Tianchao , Zhou Miao 
Published: February 2024

Abstract
Two-dimensional Bi grown on semiconductor substrate, a large-gap quantum spin Hall insulator characterized by a (p

x
, p

y
)-orbital hexagonal lattice, has been theoretically proposed and experimentally confirmed. Here, by combining tight-binding modeling with first-principles calculations, we investigate the electronic structures and quantum transport properties of Bi nanoribbons (NRs), focusing on the topological edge states for nanoelectronics. We reveal that band gap emerges due to the quantum confinement, and the gaps size depends crucially on the width and edge shape: for zigzag NRs, the gap decreases monotonically with the increase of width; while for armchair NRs, it can be categorized into three subgroups with band-gap hierarchies of

E

g

(
3
p
−
1
)

>

E

g

(
3
p
)

>

E

g

(
3
p
+
1
)

, so that the overall relation is an oscillating dependence dumped by 1/width decay. Quantum transport calculations demonstrate that the conductance is quantized to 2

e

2

/

h

, and an applied gate voltage can efficiently regulate the conductance plateau, originating from the interplay between gate voltage and topological gaps. Furthermore, the quantized conductance remains robust against strong disorder, suggesting the unique advantage of topological states for electronic transport. This work not only provides fundamental insights into the electronic properties of topological insulator nanostructures, but also sheds light on the potential applications of exotic states for quantum devices compatible with semiconductor technology.
Conserved vectors and symmetry solutions of the Landau–Ginzburg–Higgs equation of theoretical physics
Authors: Khalique Chaudry Masood , Lephoko Mduduzi Yolane Thabo 
Published: February 2024

Abstract
This paper is devoted to the investigation of the Landau–Ginzburg–Higgs equation (LGHe), which serves as a mathematical model to understand phenomena such as superconductivity and cyclotron waves. The LGHe finds applications in various scientific fields, including fluid dynamics, plasma physics, biological systems, and electricity-electronics. The study adopts Lie symmetry analysis as the primary framework for exploration. This analysis involves the identification of Lie point symmetries that are admitted by the differential equation. By leveraging these Lie point symmetries, symmetry reductions are performed, leading to the discovery of group invariant solutions. To obtain explicit solutions, several mathematical methods are applied, including Kudryashov’s method, the extended Jacobi elliptic function expansion method, the power series method, and the simplest equation method. These methods yield solutions characterized by exponential, hyperbolic, and elliptic functions. The obtained solutions are visually represented through 3D, 2D, and density plots, which effectively illustrate the nature of the solutions. These plots depict various patterns, such as kink-shaped, singular kink-shaped, bell-shaped, and periodic solutions. Finally, the paper employs the multiplier method and the conservation theorem introduced by Ibragimov to derive conserved vectors. These conserved vectors play a crucial role in the study of physical quantities, such as the conservation of energy and momentum, and contribute to the understanding of the underlying physics of the system.
Nonlocal symmetries, soliton-cnoidal wave solution and soliton molecules to a (2+1)-dimensional modified KdV system
Authors: Wang Jianyong , Ren Bo 
Published: February 2024

Abstract
A (2+1)-dimensional modified KdV (2DmKdV) system is considered from several perspectives. Firstly, residue symmetry, a type of nonlocal symmetry, and the Bäcklund transformation are obtained via the truncated Painlevé expansion method. Subsequently, the residue symmetry is localized to a Lie point symmetry of a prolonged system, from which the finite transformation group is derived. Secondly, the integrability of the 2DmKdV system is examined under the sense of consistent tanh expansion solvability. Simultaneously, explicit soliton-cnoidal wave solutions are provided. Finally, abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.
B meson rare decays in the TNMSSM*
Authors: Chen 陈 Hai-Xiang 海翔 , Cui 崔 Sheng-Kai 生恺 , Zhu 朱 Ning-Yu 宁宇 , Zhang 张 Zhao-Yang 兆阳 , Hu 胡 Huai-Cong 怀聪 
Published: February 2024

Abstract
We investigate the two loop electroweak corrections to B meson rare decays

and

in the minimal supersymmetry standard model (MSSM) extension with two triplets and one singlet (TNMSSM). The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios

and

, and the corrections from two loop diagrams to the process

can reach around

. Considering the latest experimental measurements, the numerical results of

and

in the TNMSSM are presented and analyzed. The findings indicate that the results in the TNMSSM can fit the updated experimental data well, and the new parameters

, clearly affect the theoretical predictions of

and

.
Thermodynamic properties and phase diagram of quark matter within non-extensive Polyakov chiral SU (3) quark mean field model
Authors: Singh Dhananjay , Kumar Arvind 
Published: February 2024

Abstract
In the present study, we applied Tsallis non-extensive statistics to investigate the thermodynamic properties and phase diagram of quark matter in the Polyakov chiral SU(3) quark mean field model. Within this model, the properties of the quark matter were modified through the scalar fields

, vector fields

, ϕ, and Polyakov fields Φ and

at finite temperature and chemical potential. Non-extensive effects were introduced through a dimensionless parameter q, and the results were compared to those of the extensive case (

). In the non-extensive case, the exponential in the Fermi-Dirac (FD) function was modified to a q-exponential form. The influence of the q parameter on the thermodynamic properties, pressure, energy, and entropy density, as well as trace anomaly, was investigated. The speed of sound and specific heat with non-extensive effects were also studied. Furthermore, the effect of non-extensivity on the deconfinement phase transition as well as the chiral phase transition of

and s quarks was explored. We found that the critical end point (CEP), which defines the point in the

phase diagram where the order of the phase transition changes, shifts to a lower value of temperature,

, and a higher value of chemical potential,

, as the non-extensivity is increased, that is,

1.
Molecular components in J/ψ and ρ-π puzzle*
Authors: Guo 郭 Xing-Dao 星导 , Chen 陈 Dian-Yong 殿勇 , Li 李 Xue-Qian 学潜 , Yuan 苑 Zhong-Yuan 仲元 , Sang 桑 Shijing 士晶 
Published: February 2024

Abstract
Motivated by the large branching fractions of

and the light exotic candidates, we found that there may exist molecular states composed of

and

, which correspond to

and

observed a few decades ago. The branching fractions of

and

to various

and

channels were estimated in the molecular scenario. In addition, the large branching fractions of

indicate sizable molecular components in the

state. Thus, we consider

as the superposition of the

,

, and

molecular states. These molecular components have a significant impact on the light hadron decays of

, which may elucidate the long standing

puzzle.
Research on optical fiber current transducer using nv center in diamond
Authors: Song Qiang , Yang Lu , Zhang Dingqu , Dang Sanlei , Xing Likun , Liu Jing 
Published: February 2024

Abstract
Diamond nitrogen-vacancy (NV) center has been widely employed in experimental magnetic field measurement using continuous wave optical detection magnetic resonance (ODMR), which makes it possible for current sensing. An optical fiber current transducer prototype using an NV center is built for electric power application. The DC measurement with an error of less than 4% within 500 A is realized, in which the error of 50 A to 450 A is better than 2%, and the low-frequency AC measurement is preliminarily realized. In this essay, the accuracy of low current measurement is primarily affected by system noise, while the accuracy of heavy current is mainly affected by the width of the ODMR resonance peak. Optimizing the optical path as well as sensing structure meanwhile updating the demodulation algorithm of the measured data is the following work to improve the measurement accuracy.
A coordination control strategy for parallel-connected boost converters in dc microgrid
Authors: Lin Jinwei , Wang Dongsheng , Zhang Le , Ji Tao , Wang Hui 
Published: February 2024

Abstract
Due to the constant power loads (CPLs), the system damping of the DC microgrid is reduced, which will lead to the collapse of bus voltage. In addition, the errors of current sharing amplify due to different line impedances. To address these issues, a hybrid coordination control strategy is proposed for parallel-connected boost converters, which realizes stable control and maintains the accuracy of the current distribution. Firstly, a passivity-based control (PBC) with a proportional-integral (PI) regulator is developed. The virtual damping-based PBC enhances the system damping and the PI regulator eliminates errors. On this basis, a secondary voltage control (SVC) featuring simplicity and weak dependence on communication is introduced to remove the errors of current distribution. Finally, the hybrid coordination control strategy is verified by RT-LAB-based hardware in the loop (HIL) experiment.