bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal conductivity of wrinkled graphene ring with defects
Authors: Ji Qingxiang , Li Bohan , Kadic Muamer , Wang Changguo 
Published: April 2024

Abstract
Graphene rings have great prospects in the fields of biological modulators, electrochemical biosensors, and resonators, but are prone to wrinkling which can affect their physical properties. This work establishes a theoretical model predicting the torsional wrinkling behavior of defective monolayer graphene rings, which provides direct understanding and reliable accuracy of the wrinkle levels. Then the thermal conductivity of wrinkled graphene rings is studied considering different wrinkle levels, defect concentrations and radii. It is found that with increased radius, defect concentration and torsional angle, the ratio of wrinkle amplitude to wavelength increases gradually. Vacancy defects and radii have more significant influences on the thermal conductivity than torsional wrinkles. The main influence mechanism of wrinkles and defects on thermal conductivity is revealed by phonon density of state. This work provides theoretical guidance for thermal manipulation based on the wrinkle-tuning approach.
Multi-beam coherent Fourier scatterometry
Authors: Soman S , Horsten R C , Scholte T , Pereira S F 
Published: April 2024

Abstract
Inspection of surface and nanostructure imperfections play an important role in high-throughput manufacturing across various industries. This paper introduces a novel, parallelised version of the metrology and inspection technique: Coherent Fourier scatterometry (CFS). The proposed strategy employs parallelisation with multiple probes, facilitated by a diffraction grating generating multiple optical beams and detection using an array of split detectors. The article details the optical setup, design considerations, and presents results, including independent detection verification, calibration curves for different beams, and a data stitching process for composite scans. The study concludes with discussions on the system’s limitations and potential avenues for future development, emphasizing the significance of enhancing scanning speed for the widespread adoption of CFS as a commercial metrology tool.
A novel cross-domain adaption network based on Se-Sk-DenseNet for remaining useful life prediction of rolling bearings under different working conditions
Authors: Guo Baosu , Li Hang , Dong Hao , Han Tianjie , Sun Yingbing , Hou Jianchang , Jiang Zhangpeng , Ni Qing 
Published: April 2024

Abstract
Effectively predicting the remaining useful life (RUL) of rolling bearings can ensure reliability and safety, minimize machine downtime, and reduce the operation and maintenance costs of enterprises. To solve the problems of data distribution discrepancy caused by different working conditions and the collected signals containing a lot of useless information and noise, a novel cross-domain adaption network (CDAN) is proposed in this study. Firstly, a novel feature extractor, squeeze-and-excitation (Se)-selective kernel (Sk)-DenseNet, is developed to extract useful critical features from the input data and remove the ineffective features by embedding Se and Sk attention blocks; besides, a new objective loss function consist of the RUL loss, the multi-kernel maximum mean discrepancy loss, the contrastive loss, and the Kullback–Leibler divergence loss, is proposed to solve the problem of data distribution shift; finally, the effectiveness and superiority of CDAN are proved on the PHM2012 bearings dataset. The results demonstrate that CDAN can extract deep critical features and achieve the high cross-domain RUL prediction accuracy under different working conditions.
An adaptive threshold-selected symplectic geometry mode decomposition for application to multi-modulation complex fault signals
Authors: Lv Zhe , Li Congming , Xiong Xiaoyan , Wang Xiangrong , Song Wei , Wu Bing 
Published: April 2024

Abstract
The signals obtained from complex mechanical systems are characterized by multilevel modulation and strong noise, which can lead to difficulties in fault feature extraction. Symplectic geometry mode decomposition (SGMD) proves to be a valid approach for decomposing signals. However, inaccurate threshold selection in the iterative decomposition process can compromise the quality of fault diagnosis results. To address the shortcomings of SGMD, this paper proposes adaptive SGMD with adaptive threshold selection for fault diagnosis. Based on minimum dispersion entropy indicators, correlation coefficient and stopping thresholds are adaptively chosen using the proposed enhanced dung beetle optimizer algorithm. Then the optimal symplectic geometry component (SGC) is filtered based on the value of the integrated indicators after decomposition. Finally, the optimal SGC is analyzed by envelope demodulation to extract gear fault information. Through simulation and experimental analysis, this method surpasses SGMD and other signal decomposition methods in the aspect of fault feature extraction and noise robustness. Additionally, the results indicate an increase in feature energy ratio by 2.14%–9.85% compared to SGMD. The paper demonstrates that the proposed method extracts the fault feature frequencies of gears more effectively in complex mechanical systems.
A novel subdomain adaptive intelligent fault diagnosis method based on multiscale adaptive residual networks
Authors: Wang Jinrui , Lv Xingwang , Xu Yufeng , Wan Yanbin , Bao Huaiqian , Han Baokun , Zhang Zongzhen 
Published: April 2024

Abstract
Traditional fault diagnosis methods may not capture key information during feature extraction due to the large distribution difference under different working conditions, which can result in poor accuracy of the diagnostic model. To address this issue, a subdomain adaptive bearing fault identification method guided by the local maximal mean difference (LMMD) under the multiscale adaptive residual network is proposed in this paper. The bearing vibration signals are preprocessed by wavelet convolution and wide convolution to generate initial features. Then, the multi-scale adaptive residual network is used to adjust the feature weights of different scales and extract richer feature information. To reduce the intra-class distribution difference, the LMMD is employed. Additionally, local interclass maximum mean difference (LIMMD) is used to increase the inter-class difference, preventing misclassification of samples from different classes due to their close proximity and achieving sub-domain distribution alignment. The fault diagnosis performance of the domain distance metric model guided by LMMD and LIMMD under the multiscale adaptive residual network is verified through two different bearing model validation experiments.
Atomistic simulation of the influence of semi-coherent interfaces in the V/Fe bilayer system on plastic deformation during nanoindentation
Authors: Hamdani Soumia , Abdeslam Saad , Hartmaier Alexander , Janisch Rebecca 
Published: April 2024

Abstract
Semi-coherent interfaces can have a strong influence on the mechanical behavior of bilayer systems, which is seen very clearly under indentation conditions where a well-defined plastic zone interacts directly with the interface. The main aim of this work is to study the influence of a semi-coherent bcc/bcc interface in the V/Fe bilayer system with molecular dynamics (MD) simulations. In particular, the influence of the V layer thicknesses on the apparent hardness of bilayer system is investigated. Our results show that the deformation behavior of pure V and pure Fe resulting from the MD simulations is in good agreement with the literature. Moreover, the MD simulations reveal a significant enhancement of the hardness of V/Fe bilayer system for thinner vanadium layers, resulting from the crucial role of the semi-coherent interface as a barrier to dislocation propagation. This is seen from a detailed analysis of the interaction of mobile dislocations in the plastic zone with misfit dislocations in the interface. Our work shows that dislocation pile-ups at the interface and formation of horizontal shear loops are two key mechanisms dominating the rate and magnitude of plastic deformation and thus contributes to our understanding of mechanical behavior of bilayer systems with semi-coherent interfaces.
Building a cm2 scale CVD graphene-based gas sensor: modelling the kinetic with a three-site adsorption/desorption Langmuir model
Authors: Malesys V , Andrieux-Ledier A , Lavenus P , Simon L 
Published: April 2024

Abstract
In this article, we aim to develop and study a highly sensitive and selective cm2 scale graphene-based gas sensor. We present the technology used to fabricate sensors which integrate monolayer chemical vapour deposition graphene: photolithography and transfer of layers. Characterization techniques (optical microscopy, AFM, micro-Raman spectroscopy, transport electrical measurements) ensure a diagnosis of graphene ribbons and allow good reproducibility of technological processes. We present the results of gas characterizations after a 200 ppm NO2 exposure. We propose a novel approach for the modelling of the sensor response with a three-site adsorption/desorption Langmuir model. This innovative way of modelling the sensor response should provide a better understanding of the sensor’s kinetic and help to overcome the long response time observed with graphene gas sensors.
Gate-bias stability of triple-gated feedback field-effect transistors with silicon nanosheet channels
Authors: Heo Hyojoo , Shin Yunwoo , Son Jaemin , Ryu Seungho , Cho Kyoungah , Kim Sangsig 
Published: April 2024

Abstract
In this study, we investigate the gate-bias stability of triple-gated feedback field-effect transistors (FBFETs) with Si nanosheet channels. The subthreshold swing (SS) of FBFETs increases from 0.3 mV dec−1 to 60 and 80 mV dec−1 in p- and n-channel modes, respectively, when a positive bias stress (PBS) is applied for 1000 s. In contrast, the SS value does not change even after a negative bias stress (NBS) is applied for 1000 s. The difference in the switching characteristics under PBS and NBS is attributed to the ability of the interface traps to readily gain electrons from the inversion layer. The switching characteristics deteriorated by PBS are completely recovered after annealing at 300 °C for 10 min, and the characteristics remain stable even after PBS is applied again for 1000 s.
Quasi-static crashworthiness behaviour of auxetic tubular structures based on rotating deformation mechanism
Authors: Solak Kemal , Orhan Suleyman Nazif 
Published: April 2024

Abstract
Auxetic materials have attracted significant interest due to their exceptional mechanical characteristics and distinctive deformation modes. Nevertheless, the practical use of these materials in engineering is constrained by their limited ability to absorb energy. Thus, enhancing the energy absorption (EA) capabilities of auxetic materials is crucial to expand their range of potential applications. In this study, the EA capabilities of auxetic tubular structures with rotating deformation mechanisms are examined, with a specific emphasis on three different perforation shapes: elliptic, peanut, and square, along with their modified versions incorporating stiffeners. The study employs a combination of experimental testing and numerical modelling, utilising ANSYS/LS-DYNA to evaluate various crashworthiness parameters. These parameters include total EA, specific EA, maximum crushing force, and crushing force efficiency, all of which are assessed under quasi-static compression conditions. The research highlights the importance of perforation shape and stiffener incorporation in enhancing crashworthiness. Results show that elliptic perforations exhibit superior EA and stiffened auxetic models outperform conventional ones in terms of crash absorber performance. The presence of stiffeners significantly improves the ability of tubular structures to withstand crushing forces. Furthermore, the study validates the numerical model against experimental findings, demonstrating a high level of agreement in terms of crushing force–displacement, EA, and failure modes. The research provides valuable insights into the design and performance of crashworthy structures and offers potential applications in various fields where impact resistance and EA are critical.
Third order nonlinear correlation of the electromagnetic vacuum at near-infrared frequencies
Authors: Settembrini Francesca Fabiana , Herter Alexa , Faist Jérôme 
Published: April 2024

Abstract
In recent years, electro-optic sampling, which is based on Pockel’s effect between an electromagnetic mode and a copropagating, phase-matched ultrashort probe, has been largely used for the investigation of broadband quantum states of light, especially in the mid-infrared and terahertz frequency range. The use of two mutually delayed femtosecond pulses at near-infrared frequencies allows the measurement of quantum electromagnetic radiation in different space-time points. Their correlation allows therefore direct access to the spectral content of a broadband quantum state at terahertz frequencies after Fourier transformation. In this work, we will prove experimentally and theoretically that when using strongly focused coherent ultrashort probes, the electro-optic sampling technique can be affected by the presence of a third-order nonlinear mixing of the probes’ electric field at near-infrared frequencies. Moreover, we will show that these third-order nonlinear phenomena can also influence correlation measurements of the quantum electromagnetic radiation. We will prove that the four-wave mixing of the coherent probes’ electric field with their own electromagnetic vacuum at near-infrared frequencies results in the generation of a higher-order nonlinear correlation term. The latter will be characterized experimentally, proving its local nature requiring the physical overlap of the two probes. The parameters regime where higher order nonlinear correlation results predominant with respect to electro-optic correlation of terahertz radiation is provided.
Multifunctional topological photonic crystal device for multichannel frequency routing and highly sensitive refractive index sensing
Authors: AbdelAll Naglaa , Almokhtar Mohamed , Khouqeer Ghada , Esmail Mohamed Saleh M , Abood Israa , El Soliman Sayed 
Published: April 2024

Abstract
We propose a novel photonic crystal (PC) structure with C-4 symmetry of the square lattice that utilizes topological edge states (TESs) to achieve multichannel frequency routing and high-sensitivity refractive index (RI) sensing. The proposed system combines trivial and nontrivial unit cells to form a unique lattice arrangement that supports multiple TESs. These states enable the realization of seven distinct output ports, each capable of transmitting a specific frequency, significantly enhancing optical communication systems’ bandwidth and data transfer capabilities. This feature makes the proposed PC structure an ideal candidate for multichannel frequency routing applications. Additionally, the structure incorporates a central cavity that exhibits robust light localization, making it highly sensitive to changes in the surrounding medium’s refractive index. Simulations demonstrate that the proposed structure can achieve RI sensing sensitivity of up to 721 nm/RIU, coupled with a high-quality factor exceeding

10

5

.

With its exceptional RI sensing capabilities, the proposed multichannel PC device holds immense potential for various technological advancements in frequency routing.
Perturbative and semi-analytical solutions to Teukolsky equations for massive fermions
Authors: Villani Mattia 
Published: April 2024

Abstract
In this work, we aim at solving the Teukolsky equations for a fermion with mass m

e
≠ 0 in the presence of a rotating black hole with mass M. We consider two different regimes:

m

˜

e

=

M

−
1

m

e

≪
1

and a
ω ≪ 1;

m

˜

e

≪
1

and a
ω ≳ 1. We treat each of these two regimes in different ways: we use a perturbative approach for the first, similar to the usual one employed for spin 0, 1, 2 and mass-less 1/2 fields, but with two small parameters (aω and

m

˜

e

); as we shall see, the second can be treated with a semi-analytical approach. In a forthcoming paper we shall study the remaining two cases in which

m

˜

e

≳
1

, while a
ω ≪ 1 or a
ω ≳ 1. The regime with

m

˜

e

≪
1

, but a
ω ≳ 1 is probably the most interesting from the astrophysics point of view, but this last two cases might be of some interest for the study of the interaction of fermions with very small black holes, which may be formed, for example, in the last stages of the Hawking evaporation.
What should we understand by the four-momentum of physical system?
Authors: Fedosin Sergey G 
Published: April 2024

Abstract
It is shown that, in general, in curved spacetime, none of the known definitions of four-momentum correspond to the definition, in which all the system’s particles and fields, including fields outside matter, make an explicit contribution to the four-momentum. This drawback can be eliminated under the assumption that the primary representation of four-momentum is the sum of two nonlocal four-vectors of the integral type with covariant indices. The first of these four-vectors is the generalized four-momentum, found with the help of Lagrangian density. The time component of the generalized four-momentum, in theory of vector fields, is proportional to the particles’ energy in scalar field potentials, and the space component is related to vector field potentials. The second four-vector is the four-momentum of fields themselves, and its time component is related to the energy given by tensor invariants. As a result, the system’s four-momentum is defined as a four-vector with a covariant index. The standard approach makes it possible to find the four-momentum in covariant form only for a free point particle. In contrast, the obtained formulas for calculating the four-momentum components are applied to a stationary and moving relativistic uniform system, consisting of many particles. In this case, the main fields of the system under consideration are taken into account, including the electromagnetic and gravitational fields, the acceleration field and the pressure field. All these fields are considered vector fields, which makes it possible to unambiguously determine the equations of motion of the fields themselves and the equations of motion of matter in these fields. The formalism used includes the principle of least action, charged and neutral four-currents, corresponding four-potentials and field tensors, which ensures unification and the possibility of combining fields into a single interaction. Within the framework of the special theory of relativity, it is shown that due to motion, the four-momentum of the system increases in proportion to the Lorentz factor of the system’s center of momentum, while in the matter of the system the sum of the energies of all fields is equal to zero. The calculation of the integral vector’s components in the relativistic uniform system shows that the so-called integral vector is not equal to four-momentum and is not a four-vector at all, although it is conserved in a closed system. Thus, in the theory of relativistic vector fields, the four-momentum cannot be found with the help of an integral vector and components of the system’s stress-energy tensor, in contrast to how it is assumed in the general theory of relativity.
On the dispersionless Davey-Stewartson hierarchy: the tau function, the Riemann-Hilbert problem and the Hamilton-Jacobi theory
Authors: Yi Ge , Hu Rong , Tian Kelei , Xu Ying 
Published: April 2024

Abstract
The dDS (dispersionless Davey-Stewartson) hierarchy is constructed by two eigenfunctions of a special Hamiltonian vector field. This hierarchy consists of the infinite symmetries of the dDS system. Further, this paper explores the tau function, the Riemann-Hilbert problem and Hamilton-Jacobi theory related to dDS hierarchy.
Evaluation of shielding properties of a developed nanocomposite from intercalated attapulgite clay by Cd/Pb oxides nanoparticles
Authors: Negm Hani H , El-Sharkawy Rehab M , Abdeltwab Eslam , Mostafa Massaud , Mahmoud Mohamed E , El-Taher Atef 
Published: April 2024

Abstract
The study investigated new nanocomposites’ γ-ray and neutron shielding properties based on raw attapulgite, a clay matrix intercalated with different weight percentages of mixed nano metal oxides CdO and PbO. The various percentages were as follows: (100–2x)% Attapulgite + x%CdO + x%PbO, abbreviated as (AT100–2x
CdxPb
x
), where x = 5, 10, 15%. The nanocomposites were characterized using XRD, FTIR, and EDX, confirming their successful preparation. SEM images revealed that the mixed oxide nanoparticles were successfully intercalated into the layers of attapulgite clay, with an average particle size of approximately 31.46 nm. The bulk densities of the prepared nanocomposites were measured to be in the range of 2.034 to 2.555 g/cm3. GEANT4 simulations were employed to evaluate the nanocomposites’ γ-ray and neutron shielding performance in the photon energy range of 0.015 to 15 MeV. Phys-X code was used for verification. The simulation results showed a maximum difference of approximately 9.5% between GEANT4 and Phys-X predictions. To assess the γ-ray shielding performance, various shielding parameters were calculated at selected photon energies. The μ

m
values ranged from 4.589 to 0.020 cm2.g−1, 6.311 to 0.021 cm2.g−1, 8.350 to 0.022 cm2.g−1 and 10.804 to 0.023 cm2.g−1 for raw attapulgite, AT90Pb5Cd5, AT80Pb10Cd10, AT70Pb15Cd15 across the photon energy range. The AT70Pb15Cd15 nanocomposite exhibited the highest μ

m
, Z

eff
, Z

eq
, and the lowest T
1/2, T
1/10, and MFP values. Notably, it also demonstrated the highest FNRCS (approximately 0.1 cm−1). These findings suggest that clay-based nanocomposites represent a new class of low-cost, locally available advanced materials with potential applications in γ-ray and neutron shielding characteristics.
A novel entanglement functions-based 4D fractional-order chaotic system and its bifurcation analysis
Authors: Tang Xiaoyue , Li Ruihong , Huang Dongmei 
Published: April 2024

Abstract
A novel 4D fractional-order chaotic entanglement system based on sinusoidal functions is established in this paper. We aim to reveal the relationship between the dynamical behavior of the new system and its entanglement coefficients. It is found that the equilibrium point of the system varies regularly with the successive change of the entanglement coefficient. The supercritical pitchfork bifurcation phenomenon of the new system is discussed based on the fractional-order stability theory. Furthermore, sufficient conditions and threshold for supercritical Hopf bifurcation caused by the entanglement coefficient are provided. Finally, the route to chaos of the new system is explored utilizing multiple numerical indicators, such as spectral entropy complexity, bifurcation diagrams, Lyapunov exponential spectrum, phase portraits, and 0–1 test curves. The results indicate that in addition to various chaotic attractors, there are phenomena such as period-doubling bifurcations, period windows, and coexisting symmetric attractors (periodic or chaotic).