bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic tunable narrow-band perfect absorber for fiber -optic communication band based on liquid crystal
Authors: Liu Mingliang , Li Boxun , Zeng Lili , Wei Yi , Wen Ruquan , Zhang Xingjiao , Deng Chaosheng 
Published: September 2023

Abstract
At present, most of the reported metasurface structure absorbers show that its working band cannot be regulated actively. In this study, a dynamic tunable narrow-band perfect absorption structure for fiber-optic communication band based on liquid crystal (LC) is proposed and studied. The structure is mainly composed of two effective tiers. The top tier gold array and the bottom tier reflective gold film, which are separated by a SiO2-LC dielectric medium interlayer to form a metal–dielectric–metal structure. Due to the unique optical properties of LCs, its index of refraction can be changed by adjusting the bias voltage and temperature, so as to adjust the resonance wavelength actively. The designed structure is analyzed by finite element method and the coupled mode theory is used to verify the analysis results. The designed structure has a 99.92% absorption effect in the most commonly used band of fiber-optic communication. Due to the symmetry of the absorber structure, the device is not sensitive to the polarization state of the excitation source. Moreover, the absorber exhibits an unusual dependence on the incident angle, which can be attributed to the anisotropy of the LC. Based on the dependence of incident angle, a plasma optical switch with large ON/OFF ratio (η) of 27.395 dB and nearly flawless modulation depth of 99.818% can be realized. It is believed that this structure can provide a method for the dynamic control of near infrared electromagnetic waves, and to be applied in electromagnetic energy absorption, filtering and plasma optical switch system.
A broadband low-profile microwave absorber based on ferromagnetic material doped hybrid stereo metamaterial
Authors: Wei Xuyao , Wang Jiajia , Zhou Fangkun , Tan Ruiyang , Liu Jun , Chen Ping 
Published: September 2023

Abstract
This study introduces a ferromagnetic material-doped hybrid stereo metamaterial absorber (HSMA) that has been developed to overcome the limitations in broadband absorption of electromagnetic wave. This metamaterial combines a ferromagnetic block with a blind via in the center and a standing resistive trapezoidal patch together in a stereo meta-atom to enable a continuous and broad absorption band for 90% absorptivity from 2.3 GHz to 40 GHz, with a thickness only as 0.079 times the maximum working wavelength. The hybrid absorber also exhibits angular stability under oblique incidence and polarization insensitivity. Furthermore, a sample of proposed HSMA was fabricated and measured. The broadband absorption properties of such hybrid stereo metamaterial were validated by both simulated and experimental results. Our study provides a promising implementation approach for broadband and low-profile microwave absorbers.
Optical signal-based improvement of individual nanoparticle tracking analysis
Authors: Nguyen Minh-Chau , Bon Pierre 
Published: September 2023

AbstractNanoparticle tracking analysis (NTA) provides a simple method to determine individual nanoparticle (NP) size. However, because size quantification is based on the slowly converging statistical law of random events, its intrinsic error is large, especially in the case of limited event numbers, e.g. for weak scattering NPs. Here, we introduce an NTA improvement by analyzing each individual NP trajectory while taking into account the other trajectories with a weighting coefficient. The weighting coefficient is directly derived from the optical signature of each particle measured by quantitative phase microscopy. Simulations and experimental results demonstrate the improvement in NTA accuracy, not only for mono-disperse but also for poly-disperse particle solutions.
An effective method for fault diagnosis of rotating machinery under noisy environment
Authors: Xu Yonghui , Lu Xiang 
Published: September 2023

Abstract
Rotating machinery is widely utilized as mechanical equipment in the industrial field. However, due to the complex working conditions, the existing fault diagnosis methods have failed to address good results in practical applications. To improve the fault diagnosis performance of rotating machinery in a noisy environment, a new multi-scale convolution neural network (MSCN) based on a self-calibrating attention module is proposed. First, this thesis constructs a multi-scale convolution layer with a wide convolution kernel to form an efficient sampling structure at the filter level, which can filter out incoherent noise from the signals and extract rich features. Second, a multi-scale self-calibrating attention module is implemented with two identical self-calibrating convolutional networks to continuously focus on significant embeddings and adaptively combine information from different spatial dimensions. Third, the multi-dimensional characteristics are integrated by the feature cascade layer, and then the fault modes are identified though the classifier layer under noise. Finally, based on the Case Western Reserve University datasets and Paderborn University bearing datasets, the experimental results show that our proposed MSCN can significantly enhance the fault identification ability to rotate machinery in a noisy environment.
Constructing a noble-metal-free 0D/2D CdS/SnS2 heterojunction for efficient visible-light-driven photocatalytic pollutant degradation and hydrogen generation
Authors: Hu Hanmei , He Yunyun , Yu Hong , Li Dongcai , Sun Mei , Feng Yanyan , Zhang Chuanyue , Chen Haoran , Deng Chonghai 
Published: September 2023

Abstract
Semiconductor photocatalysis has attracted the attention of a wide audience for its outstanding capabilities in water purification and energy conversion. Herein, a noble-metal-free nanoheterojunction is created by planting zero-dimensional (0D) CdS nanograins, of 10–20 nm in size, on the surface of 2D SnS2 nanosheets (NSs) using an in situ chemical bathing deposition process, where SnS2 NSs have an average diameter of 400 nm and thicknesses of less than 20 nm. The possible formation mechanism of the CdS/SnS2 (CS/SS) heterogeneous nanostructure is elaborated upon. The catalytic activities over CS/SS nanocomposites for the photodegradation of organic dye and hydrogen evolution from photolysis water splitting are examined under visible light irradiation. The apparent rate constant (k) of the optimal CS/SS-3 composite in the decontamination of methylene blue (MB) is up to 3.34 and 1.87 times as high as that of pristine SnS2 and pure CdS counterparts, respectively. The optimized CS/SS-3 sample consistently achieves the highest photocatalytic hydrogen production rate, at 10.3 and 5.7 folds higher than that of solo SnS2 and CdS panels, respectively. The boosted photocatalytic capacities of CdS/SnS2 heterostructures are essentially attributed to the formation of the closely interfacial incorporation of CdS and SnS2 semiconductors, resulting in the effective charge transportation and spatial separation of the photoinduced electron–hole pairs. Furthermore, the traditional type-II charge transfer pathway is proposed based on the perfect band structure and the free radical experiment results.
Effect of fluorine doping on the NO2-sensing properties of MoS2nanoflowers
Authors: Huang Yixuan , Li Donglin , Chai Wenxiang , Jin Dingfeng , Jin Hongxiao 
Published: September 2023

AbstractThe somewhat slow recovery kinetics of NO2sensing at low temperatures are still challenging to overcome. To enhance the gas sensing property, fluorine is doped to MoS2nanoflowers by facile hydrothermal method. Extensive characterization data demonstrate that F was effectively incorporated into the MoS2nanoflowers, and that the microstructure of the MoS2nanoflowers did not change upon F doping. The two MoS2doped with varying concentrations of fluorine were tested for their sensing property to NO2gas. Both of them show good repeatability and stability. A smaller recovery time was seen in the F-MoS2-1 sample with a little amount of F loading, which was three times quicker than that of pure MoS2. The key reason for the quicker recovery time of this material was found to be the fluorine ions that had been adsorbed on the surface of F-MoS2-1 would take up some of the NO2adsorption site. Additionally, the sample F-MoS2-2 with a higher F doping level demonstrated increased sensitivity. The F-MoS2-2 sensor’s high sensitivity was mostly due to the lattice fluorine filled to the sulfur vacancy, which generated impurity levels and reduced the energy required for its electronic transition. This study might contribute to the development of new molybdenum sulfide based gas sensor.
The role of oxygen incorporation in Ni (111) substrates on the growth of hexagonal boron nitride monolayers
Authors: Li Yuan , Gomez Hector , Tran Jason , He Yanwei , Shou Chengyun , Yang Tianchen , Wei Peng , Lake Roger K , Liu Jianlin 
Published: September 2023

Abstract
Reliable and controllable growth of two-dimensional (2D) hexagonal boron nitride (h-BN) is essential for its wide range of applications. Substrate engineering is one of the critical factors that influence the growth of the epitaxial h-BN films. Here, we report the growth of monolayer h-BN on Ni (111) substrates incorporated with oxygen atoms via molecular beam epitaxy. It was found that the increase of incorporated oxygen concentration in the Ni substrate through a pretreatment process prior to the h-BN growth step would have an adverse effect on the morphology and growth rate of 2D h-BN. Under the same growth condition, h-BN monolayer coverage decreases exponentially as the amount of oxygen incorporated into Ni (111) increases. Density functional theory calculations and climbing image nudged elastic band (CI-NEB) method reveal that the substitutional oxygen atoms can increase the diffusion energy barrier of B and N atoms on Ni (111) thereby inhibiting the growth of h-BN films. As-grown large-area h-BN monolayer films and fabricated Al/h-BN/Ni (MIM) nanodevices were comprehensively characterized to evaluate the structural, optical and electrical properties of high-quality monolayers. Direct tunneling mechanism and high breakdown strength of ∼11.2 MV cm−1 are demonstrated for the h-BN monolayers grown on oxygen-incorporated Ni (111) substrates, indicating that these films have high quality. This study provides a unique example that heterogeneous catalysis principles can be applied to the epitaxy of 2D crystals in solid state field. Similar strategies can be used to grow other 2D crystalline materials, and are expected to facilitate the development of next generation devices based on 2D crystals.
Takasaki’s rational fourth Painlevé-Calogero system and geometric regularisability of algebro-Painlevé equations
Authors: Filipuk Galina , Stokes Alexander 
Published: September 2023

Abstract
We propose a notion of regularisation which extends Okamoto’s construction of spaces of initial conditions for the Painlevé differential equations to the class of systems with globally finite branching about movable singularities in the sense of the algebro-Painlevé property. We illustrate this regularisation first in the case of a Hamiltonian system obtained by Takasaki as part of the Painlevé-Calogero correspondence, which is related by an algebraic transformation to the fourth Painlevé equation. Through a combination of compactification, blowups and removal of certain curves we obtain a space on which the system is everywhere either regular or regularisable by certain algebraic transformations. We provide an atlas for this space in which the system has a global Hamiltonian structure, with all Hamiltonian functions being polynomial in coordinates just as in the case of the Painlevé equations on Okamoto’s spaces. We also compare the surface associated with the Takasaki system with that of the fourth Painlevé equation, showing that they are related by a combination of blowdowns and a branched double cover. We provide more examples of algebro-Painlevé equations regularised in this way and also discuss applications of this generalised construction of the space of initial conditions to the identification and classification of algebro-Painlevé equations.
Notes on a paper of Pokhozhaev
Authors: Boiti Chiara , Manfrin Renato 
Published: September 2023

Abstract
We prove a second order identity for the Kirchhoff equation which yields, in particular, a simple and direct proof of Pokhozhaev’s second order conservation law when the nonlinearity has the special form

(

C
1

s
+

C
2

)

−
2

. As applications, we give: an estimate of order ɛ
−4 for the lifespan T

ɛ
of the solution of the Cauchy problem with initial data of size ɛ in Sobolev spaces when the nonlinearity is given by any C
2 function

m
(
s
)
>
0

; a necessary and sufficient condition for boundedness of a second order energy of the solutions.
Artificial intelligence in breast imaging: potentials and challenges
Authors: Li Jia-wei , Sheng Dan-li , Chen Jian-gang , You Chao , Liu Shuai , Xu Hui-xiong , Chang Cai 
Published: September 2023

Abstract
Breast cancer, which is the most common type of malignant tumor among humans, is a leading cause of death in females. Standard treatment strategies, including neoadjuvant chemotherapy, surgery, postoperative chemotherapy, targeted therapy, endocrine therapy, and radiotherapy, are tailored for individual patients. Such personalized therapies have tremendously reduced the threat of breast cancer in females. Furthermore, early imaging screening plays an important role in reducing the treatment cycle and improving breast cancer prognosis. The recent innovative revolution in artificial intelligence (AI) has aided radiologists in the early and accurate diagnosis of breast cancer. In this review, we introduce the necessity of incorporating AI into breast imaging and the applications of AI in mammography, ultrasonography, magnetic resonance imaging, and positron emission tomography/computed tomography based on published articles since 1994. Moreover, the challenges of AI in breast imaging are discussed.
Power-law spectrum-based objective function to train a generative adversarial network with transfer learning for the synthetic breast CT image
Authors: Kim Gihun , Baek Jongduk 
Published: September 2023

Abstract

Objective. This paper proposes a new objective function to improve the quality of synthesized breast CT images generated by the GAN and compares the GAN performances on transfer learning datasets from different image domains. Approach. The proposed objective function, named beta loss function, is based on the fact that x-ray-based breast images follow the power-law spectrum. Accordingly, the exponent of the power-law spectrum (beta value) for breast CT images is approximately two. The beta loss function is defined in terms of L1 distance between the beta value of synthetic images and validation samples. To compare the GAN performances for transfer learning datasets from different image domains, ImageNet and anatomical noise images are used in the transfer learning dataset. We employ styleGAN2 as the backbone network and add the proposed beta loss function. The patient-derived breast CT dataset is used as the training and validation dataset; 7355 and 212 images are used for network training and validation, respectively. We use the beta value evaluation and Fréchet inception distance (FID) score for quantitative evaluation. Main results. For qualitative assessment, we attempt to replicate the images from the validation dataset using the trained GAN. Our results show that the proposed beta loss function achieves a more similar beta value to real images and a lower FID score. Moreover, we observe that the GAN pretrained with anatomical noise images achieves better equality than ImageNet for beta value evaluation and FID score. Finally, the beta loss function with anatomical noise as the transfer learning dataset achieves the lowest FID score. Significance. Overall, the GAN using the proposed beta loss function with anatomical noise images as the transfer learning dataset provides the lowest FID score among all tested cases. Hence, this work has implications for developing GAN-based breast image synthesis methods for medical imaging applications.
Tensor-conductance model for reducing the computational artifact in target tissue for low-frequency dosimetry
Authors: Diao Yinliang , Liu Li , Deng Nuo , Lyu Shilei , Hirata Akimasa 
Published: September 2023

Abstract

Objective. In protecting human from low-frequency (<100 kHz) exposure, an induced electric field strength is used as a physical quantity for assessment. However, the computational assessment suffers from a staircasing error because of the approximation of curved boundary discretized with cubic voxels. The international guidelines consider an additional reduction factor of 3 when setting the limit of external field strength computed from the permissible induced electric field. Here, a new method was proposed to reduce the staircasing error considering the tensor conductance in human modeling for low-frequency dosimetry. Approach. We proposed a tensor-based conductance model, which was developed on the basis of the filling ratio and the direction of the tissue interface to satisfy the electric field boundary condition and reduce staircasing errors in the target tissue of a voxel human model. Main results. The proposed model was validated using two-layer nonconcentric cylindrical and spherical models with different conductivity contrasts. A comparison of induced electric field strengths with solutions obtained using an analytical formula and finite element method simulation indicated that for a wide range of conductivity ratios, staircasing errors were reduced compared with a conventional scalar-potential finite-difference method. The induced electric field in a simple anatomical head model using our approach was in good agreement with finite element method for exposure to uniform magnetic field exposure and that from coil, simulating transcranial magnetic stimulation. Significance. The proposed tensor-conductance model demonstrated that the staircasing error in an inner target tissue of a voxel human body can be reduced. This finding can be used for the electromagnetic compliance assessment and dose evaluation in electric or magnetic stimulation at low frequencies.
Oil–water interface dynamics and electrical breakdown in pulsed electric field
Authors: Panov V A , Kulikov Yu M , Vetchinin S P , Pecherkin V Ya , Vasilyak L M 
Published: September 2023

Abstract
The motion of immiscible liquids and electrical breakdown at the interface of two horizontal layers of conducting water and transformer oil are studied under vertically oriented nonuniform pulsed electric field. The interface profile is tracked during experiments and shows the appearance and growth of a water cone inside the oil. After the water cone reaches the high voltage electrode located in the oil, three scenarios are observed depending on water conductivity and pulsed voltage amplitude: electrical current flows over the water without plasma formation; plasma onset occurs due to thermal breakdown in the water at the moment the cone tip touches the sphere; plasma onset occurs due to breakdown through a swarm of small water drops atomized from the cone tip under the action of electrical forces. From experiments and numerical simulations, the breakdown time is determined depending on applied voltage amplitude; the oil–water interface behavior in the electric field is analysed; and the electrical force distribution is studied. The experiment and simulation results show good agreement.
Superconducting properties of new hexagonal and noncentrosymmetric cubic high entropy alloys
Authors: Motla K , Arushi  , Jangid S , Meena P K , Kushwaha R K , Singh R P 
Published: September 2023

Abstract
Superconducting high-entropy alloys (HEAs) are a newly burgeoning field of unconventional superconductors and raise intriguing questions about the presence of superconductivity in highly disordered systems, which lack regular phonon modes. In our study, we have synthesized and investigated the superconducting characteristics of two new transition elements based HEAs Re0.35Os0.35Mo0.10W0.10Zr0.10 crystallizing in noncentrosymmetric α-Mn structure, and Ru0.35Os0.35Mo0.10W0.10Zr0.10 crystallizing in hexagonal closed-packed structure (hcp). Due to its high hardness, transition-metal-based hexagonal hcp HEA is rare and highly desirable for practical applications. Bulk magnetization, resistivity, and specific heat measurements confirmed bulk type-II superconductivity in both alloys. Specific heat analysis up to the measured low-temperature range suffices for a Bardeen-Cooper-Schrieffer explanation.
Finite-time synchronization of fractional-order chaotic system based on hidden attractors
Authors: Yan Shaohui , Zhang Hanbing , Jiang Defeng , Jiang Jiawei , Cui Yu , Zhang Yuyan 
Published: September 2023

Abstract
A new 3D fractional-order chaotic system is obtained by improving the Sprott-A system and introducing the definition of fractional calculus to it. Then the new system is certified to be chaotic by studying and analyzing the phase diagram, Lyapunov exponents, and smaller alignment index tests. Then the analysis of equilibrium points finds that the new system has virtually no equilibrium points and hidden attractors. The new system is dynamically analyzed by bifurcation diagram, time-domain waveform and complexity, it is indicated that the system is susceptible to initial conditions, and with the changes of different parameters the system produced different scroll types of attractors. In addition, to verify the feasibility of the system, a simulation circuit design based on Multisim is therefore carried out. Finally, the finite-time synchronization of the fractional-order system is successfully achieved by taking advantage of the high security of the hidden attractors.
Analysis of spatial damage characteristics of rock under multiple high-voltage pulse discharges: I. Cross-section characteristics
Authors: Zhao Yong , Zhang Qin , Liu Yi , Huang Shijie , Wang Tianyu , Liu Siwei , Lin Fuchang 
Published: September 2023

Abstract
Rock breaking by high-voltage pulse discharge (rock breaking by high-voltage pulse discharge, RHPD) is an efficient technology for rock breaking. A single discharge will lead to the initiation or expansion of cracks inside the rock, and the expansion of cracks after multiple discharges will lead to the destabilization of the rock and finally produce a fractured zone. Because of the difficulty in quantifying the spatial damage characteristics of the fractured zone, in this paper, based on the discrete element method and theoretical analysis, the spatial damage model (spatial damage model, SDM) of rock is established. For a typical liquid-solid combination, from the microscopic point of view, the damage characteristics of the fractured zone on the radial cross-section of the plasma are quantified. The changing characteristics of the damage characteristics were analyzed for multiple discharges. In addition, an experimental platform has been built, and the accuracy of the SDM has been verified by the experimental results. The results show that the increase in the discharge distance will improve the deposition energy and crushing effect, and will also improve the accuracy of the model. The findings of this paper provide a technical reserve for the application of RHPD.