bluuebunny/crossref_metadata_2025_split huggingface dataset:
Industrial image anomaly detection based on multi Gaussian discriminant model and robust core set
Authors: Wei Ran , Li ZhengYang , Geng Lei , Wuken Muheiti , Liu YanBei 
Published: August 2024

AbstractTo address the issue of false positive (FP) detections in image anomaly detection caused by the loss of low-frequency features when dealing with high-dimensional feature distributions, we propose the multi-layer Gaussian discriminant anomaly detection model (MGAD). This model utilizes distance metrics based on multiple normal distributions to perform anomaly detection. By mining multi-layer feature combinations from normal samples and incorporating a Gaussian mixture model strategy for pixel-by-pixel probability density estimation, a weighting mechanism is designed to emphasize the role of low-frequency features in Gaussian space. This approach effectively models data collections that do not follow a single normal distribution as a mixture of several Gaussian distributions, thereby reducing false detections. Additionally, we propose a method for calculating the minimum Mahalanobis distance based on the estimation of the minimum covariance determinant. By identifying a subset with the smallest covariance matrix determinant, this method enhances the robust estimation of the data’s central position and spread, thereby reducing the impact of outliers. On the MVTec-AD dataset, MGAD demonstrates outstanding performance with an anomaly detection area under the receiver operating characteristic curve (AUROC) of 98.8%, the anomaly localization AUROC of 98.2%, and the per-class true negative rate for normal samples of 93.1%. Compared with the state-of-the-art models, MGAD improves the detection accuracy for normal samples by 3.6%, demonstrating the best performance among all models. These results highlight the model’s excellent capability in anomaly recognition and reduction of FPs.
A high-throughput statistical homogenization technique to convert realistic microstructures into idealized periodic unit cells
Authors: Foster S Caleb , Wilkerson Justin W 
Published: August 2024

Abstract
Metal alloys frequently contain distributions of second-phase particles that deleteriously affect the material behavior by acting as sites for void nucleation. These distributions are often extremely complex and processing can induce high levels of anisotropy. The particle length-scale precludes high-fidelity microstructure modeling in macroscale simulations, so computational homogenization methods are often employed. These, however, involve simplifying assumptions to make the problem tractable and many rely on periodic microstructures. Here we propose a methodology to bridge the gap between realistic microstructures composed of anisotropic, spatially varying second-phase void morphologies and idealized periodic microstructures with roughly equivalent mechanical responses. We create a high-throughput, parametric study to investigate 96 unique bridging methods. We apply our proposed solution to a rolled AZ31B magnesium alloy, for which we have a rich dataset of microstructure morphology and mechanical behavior. Our methodology converts a µ-CT scan of the realistic microstructure to idealized periodic unit cell microstructures that are specific to the loading orientation. We recreate the unit cells for each parameter set in a commercial finite element software, subject them to macroscopic uniaxial loading conditions, and compare our results to the datasets for the various loading orientations. We find that certain combinations of our parameters capture the overall stress–strain response, including anisotropy effects, with some degree of success. The effect of different parameter options are explored in detail and we find that excluding certain particle populations from the analysis can give improved results.
Machining mechanism of CoCrFeNiAlX high entropy alloys via ultrasonic elliptical vibration cutting
Authors: Zhang Ping , Wang Shunxiang , Sun Yajie , Zhang Jinlong , Yue Xiujie , Gao Yeran 
Published: August 2024

Abstract
This study investigates the micro-cutting mechanism of CoCrFeNiAl
X
high entropy alloys, focusing on the impact of amplitude, vibration frequency, cutting depth, and the Al element content. The mechanical response of the material is analyzed using simulation methods for both conventional cutting and ultrasonic elliptical vibration assisted cutting (UEVAC). The results show that under different vibration parameters and cutting depth, the cutting temperature produced by UEVAC is significantly higher than that of conventional cutting temperature. When the Y-axis amplitude is reduced from 90 μm to 30 μm, the cutting temperature is reduced by 50%. In addition, the cutting temperature is positively correlated with the Al content, and when the molar ratio is 20%, the cutting temperature is about 2.1 times that of 13%. While keeping the cutting parameters unchanged, the cutting force generated by UEVAC is significantly reduced compared to conventional cutting. It is worth noting that when the X-axis amplitude is 40 μm, the Y-axis amplitude is 90 μm, and the vibration frequency is 25 KHz, the cutting force of UEVAC is the smallest, which is only about 13% of the conventional cutting force. With the increase of the mole ratio of aluminum in the high entropy alloy, when the mole ratio of aluminum increases from 0% to 13%, the cutting force begins to decrease by about 33%. However, when the molar ratio increases from 13% to 20%, the cutting force increases by about 214%. On the surface of the workpiece (within the range of 0–3 μm from the machining surface), the residual stress generated by UEVAC is mainly manifested as compressive stress or tensile stress, which is significantly less than the residual stress generated by conventional cutting. The relation of residual compressive stress of workpiece under different aluminum content is Al1 > Al0.6 > Al0.
Completely degenerate equilibria of the Kuramoto model on networks
Authors: Sclosa Davide 
Published: August 2024

Abstract
Kuramoto Networks contain non-hyperbolic equilibria whose stability is sometimes difficult to determine. We consider the extreme case in which all Jacobian eigenvalues are zero. In this case linearizing the system at the equilibrium leads to a Jacobian matrix which is zero in every entry. We call these equilibria completely degenerate. We prove that they exist for certain intrinsic frequencies if and only if the underlying graph is bipartite, and that they do not exist for generic intrinsic frequencies. In the case of zero intrinsic frequencies, we prove that they exist if and only if the graph has an Euler circuit such that the number of steps between any two visits at the same vertex is a multiple of 4. The simplest example is the cycle graph with 4 vertices. We prove that graphs with this property exist for every number of vertices

N
⩾
6

and that they become asymptotically rare for N large. Regarding stability, we prove that for any choice of intrinsic frequencies, any coupling strength and any graph with at least one edge, completely degenerate equilibria are not Lyapunov stable. As a corollary, we obtain that stable equilibria in Kuramoto Networks must have at least one strictly negative eigenvalue.
Nondestructive evaluation of debonding in composites using air-coupled coda wave analysis and local defect resonance techniques
Authors: Li Zhiqiang , Jiao Jingpin , Zheng Xiangfeng , Hao Xiaojun , He Cunfu , Wu Bin 
Published: August 2024

Abstract
Low acoustic energy conversion efficiency is a major challenge for air-coupled ultrasonic technology. In the determination of the lift-off distance of air-coupled sensors, there is a balance between the acoustic energy attenuation and the difficulty of extracting defect information. In this study, an air-coupled local defect resonance (LDR) technique with coda wave analysis is proposed for the nondestructive evaluation of debonding in composites. A sensor consisting of 19 elements was used to simultaneously excite and receive ultrasonic waves. Air-coupled LDR experiments were conducted on the two types of composite structures. The effects of sensor lift-off distance and coda wave analysis on the performance of the LDR technique were investigated. It was found that the sensor lift-off distance and the coda wave analysis had a significant effect on the defect detection capability of the LDR technique. For composites, the optimal sensor lift-off distance was found to be between 3.5λ and 5.5λ, where λ is the wavelength. Compared to multiple reflection echoes, the coda waves are more suitable for identifying the damage in composites. The proposed non-contact ultrasonic technique effectively reduces the required incident acoustic energy and can be used for efficient detection of debonding in composites.
A soft bioinspired suction cup with tunable adhesion force using shape memory alloy
Authors: Zhou Weimian , Xu Chanchan , Chen Guisong , Wang Xiaojie 
Published: August 2024

Abstract
Suction cups has been widely utilized to grasp objects, but they typically encounter challenges with sealing failure and non-adjustable adhesion force. In this study, a bioinspired suction cup integrated with an shape memory alloy actuated module was proposed to solve these problems. The actuating performance under different input current was firstly investigated to ensure the effectiveness of the module. Then, inspired by the surface structures of the tree frog’s toe pad, the synthetic bioinspired suction cups with hexagonal microstructures at the rims were designed. The regular cup with soft and smooth rim was also fabricated for comparison study. Furthermore, the adhesion performance and surface adaptability of different two cups were studied in both dry and water conditions on substrates with various roughness levels. The results indicated that the proposed active bioinspired suction cup exhibited higher pull-off strength and better sealing on less rough substrates. The proposed bioinspired suction cup possessed the advantages of compactness and lightweight, thus demonstrating potential for integration into arrayed suction grippers.
Flat-band and diverse quasi-fermions in Pb10(PO4)6O4
Authors: He Qin , Ma Da-Shuai , Fu Botao , Li Xiao-Ping 
Published: August 2024

Abstract
Employing a combination of first-principles calculations and low-energy effective models, we present a comprehensive investigation on the electronic structure of Pb10(PO4)6O4, which exhibits remarkable quasi-one-dimensional topological flat-band around the Fermi level. These flat bands predominantly originate from the

p
x

/

p
y

orbitals of the oxygen molecules chain at the fully-occupied 4e Wyckoff positions and thus can be well-captured by a minimal four-band tight-binding model. Furthermore, the abundant crystal symmetry inherent in Pb10(PO4)6O4 provides an ideal platform for the emergence of various quasi-fermions characterized by different dispersion, degeneracy, and dimensionality. These include a 0D four-fold degenerate Dirac fermion exhibiting quadratic dispersion, a 1D quadratic/linear nodal-line fermion along symmetric k-paths, a 1D hourglass nodal-line (HNL) fermion associated with the Dirac fermion, and a 2D symmetry-enforced nodal surface located on the kz
= π plane. Moreover, when considering the weak ferromagnetic order, Pb10(PO4)6O4 transforms into a rare semi-half-metal, which is characterized by the presence of Dirac fermion and HNL fermion at the Fermi level for a single spin channel exhibiting 100

%

spin polarization. Our findings reveal the rarely coexistence of flat bands, diverse topological semimetal states and ferromagnetism in Pb10(PO4)6O4, which may provide valuable insights for further exploring the intriguing interplay between superconductivity and exotic electronic states.
Exploring the effect of strong electronic correlations in Seebeck Coefficient of the NdCoO3 compound : Using experimental and DFT+U approach
Authors: Pandey Abhishek , Pandey Sudhir K 
Published: August 2024

Abstract
The presence of complexity in the electronic structure of strongly correlated electron system NdCoO3 (NCO) have sparked interest in the investigation of its physical properties. Here, we study the Seebeck coefficient (α) of NCO by using the combined experimental and DFT+U based methods. The experimentally measured Seebeck coefficient is found to be ∼444 μ
V/K at 300 K, which decreases to 109.8 μ
V/K at 600 K. In order to understand the measured Seebeck coefficient, we have calculated the PDOS and band structure of the NCO. Furthermore, the calculated occupancy of 6.4 for Co 3d orbitals and presence of large unoccupied O 2p states indicate the covalent nature of the bonding. Apart from this, the maximum effective mass is found to be 36.75 (28.13) me for the spin-up (dn) channel in conduction band indicates the n-type behaviour of the compound in contrast to our experimentally observed p-type behaviour. While, the calculated Seebeck coefficient at the temperature-dependent chemical potential (μ) at 300 K shows the p-type behaviour of the compound. Fairly good agreement is seen between the calculated and measured values of α at U
ff
= 5.5 eV and U
dd
= 2.7 eV. The maximum power factor (PF) is found to be 47.6 (114.4)×1014
μW
K
−2cm−1
s
−1 at 1100 K, which corresponds to p (n)-type doping of ∼1.4 (0.7)×1021 cm−3. This study suggests the importance of strong on-site electron correlation in understanding the thermoelectric property of the compound
Influence of thermal radiation and magnetic field on convective transfer within an inclined square enclosure filled with Cu-water nanofluid
Authors: Elôrch M , Bendaraa A , Amlal W , Harchaoui M , Charafi M M 
Published: August 2024

Abstract
The present work investigates the effects of thermal radiation and magnetic field on the laminar convective transfer process on copper-based nanofluid within an inclined square enclosure. The studied configuration is a rigid-walled cavity subjected to a horizontal temperature gradient where the left wall is maintained at a hot temperature

T

h

and subjected to a magnetic field

B

0

.

In contrast, the right wall is kept at a cold temperature

T

c

.

The horizontal walls are adiabatic. The dimensionless governing equations are solved using the finite difference method and the UPWIND scheme to solve the convective terms. Formulated using the stream function, vorticity, and temperature. Effects on mean Nusselt numbers are investigated at different Rayleigh numbers

10

4

,

10

5

,

10

6

,

Hartmann numbers

H
A
=
0

t
o

100

,

tilt angles

γ
=
0
,
π
/
6
,

π
/
4

a
n
d

π
/
3

,

nanofluid volume fractions

0
%

≤

φ

≤

6
%

and different radiation parameters (

R
d
=
0
,

1
,

2
,

3

). The findings show that the HTR increased 3.6 times by augmenting the Ra from 104 to 106. Also, increasing the Ha number from 0 to 100 causes an 83.16% reduction in the HTR. Considering the radiation mode of heat transfer causes an increase in HTR. The average Nusselt values increase by 59.72% for the concentration of 6% while increasing the radiation parameter from 0 to 3. On the other hand, an increase in volume fraction leads to a deterioration in mean Nusselt numbers (Numean).
The effect of Casimir force on a diffraction grating in an optomechanical system
Authors: Rasul Khurram , Hussain Anwar , Asghar Sobia , Ziauddin  , Dong Shi-Hai 
Published: August 2024

Abstract
This study revisits an optomechanical cavity system to investigate how the Casimir force affects the manipulation of a diffraction grating. The proposed model consists of two mirrors, one of which is fixed while the other vibrates, and an external plate is used to generate the Casimir effect through the vibrating mirror. The Casimir effect has the potential to modify the properties of the output probe field (OPF), resulting in the phenomenon known as optomechanically induced transparency (OMIT), as reported in a previous study (Sci. Rep. 6, 27 102 (2016)). Interestingly, we observed that, when the Casimir effect exist, the maximum energy is transported to higher order. This theoretical realization of the diffraction grating could be feasibly tested in a physical experiment.
In situ preparation of MoS2@Fe3O4 by radiation method and its application in flame retardancy, mechanical properties, and friction properties of EVA composites
Authors: Xu Siyi , Li Danyi , Wang Wenrui , Lin Lin , Sun Ying , Li Jihao , Li Linfan 
Published: August 2024

Abstract
In recent years, there has been significant interest in using two-dimensional MoS2 to enhance flame retardancy, which has proven challenging. MoS2@Fe3O4 nanosheets were successfully synthesized via a one-step method called radiation reduction to boost MoS2’s flame retardant properties. Incorporating these MoS2@Fe3O4 nanocomposites notably improved the flame retardancy of ethylene vinyl acetate copolymer (EVA). Compared to pure EVA, EVA nanocomposites with 1 part of MoS2@Fe3O4 showed a 17.4% reduction in peak heat release rate, 40.4% decrease in total heat release, and 52.9% reduction in total smoke release, with scaly residue content improving from 0.4% to 12.6%. Additionally, MoS2@Fe3O4 incorporation enhanced the mechanical and friction properties of EVA composites, increasing tensile strength by 25.7% and elongation at break by 10.4% compared to pure EVA. This study presents an effective and simple method for producing modified MoS2 nanosheets that enhance flame retardancy, as well as mechanical and friction properties of EVA composites.
Nanosecond-pulse fiber laser mode-locked with iron phthalocyanine
Authors: S Wadi Nurul Izzah , Jusoh Zulzilawati , Muhammad Ahmad Razif , Ahmad B A , Salam Sameer 
Published: August 2024

Abstract
In this paper, we demonstrated a passively mode-locked erbium doped fiber laser (EDFL) using iron phthalocyanine (FePc) material as a saturable absorber (SA). The FePc-SA was prepared via a casting method, integrating FePc powder with polyvinyl alcohol to form FePc-PVA film. When implemented into the mode-locked EDFL cavity, the laser generated 356 ns pulses at a repetition rate of 969 kHz. Operating at a wavelength of 1559 nm, the laser achieved pulse energy of 6.04 nJ, output power of 5.85 mW, and peak power of 0.014 W under a maximum pump power of 128.92 mW. The laser exhibited remarkable stability, evidenced by a signal-to-noise ratio of 71.7 dB at the fundamental frequency. These results demonstrate that FePc material effectively serves as a mode-locker for generating nanosecond pulses.
Au–decorated TiO2 nanoparticle photoanode: synthesis, structural, optical properties and photoelectrochemical water splitting performance
Authors: Bui Ban V. , Nguyen Tien Dai , Hau Le Van Cong , Vu Thi Bich , Le Hoang V. , Le Thi Hong Phong , Thien Nguyen Duy , Nguyen Tien-Thanh 
Published: August 2024

Abstract
This study presents a novel approach to synthesizing Au-decorated TiO2 (Au/TiO2) nanoparticles (NP) using a spin-coating method, showcasing significant advancements in photoanode development. The resulting Au/TiO2 NPs exhibit well-defined crystallite structures comprising Au and TiO2 phases, featuring Au NP sizes ranging from 2.61 nm to 6.10 nm. Notably, the energy bandgap of these Au-decorated TiO2 NPs demonstrates a discernible redshift of 3.22–3.02 eV across various Au concentrations (1%–20%). Photoluminescence spectra reveal three distinct emission peaks at room temperature in the 400–550 nm wavelength range. The water-splitting activity of the Au/TiO2 NPs is investigated through the photoelectrochemical cell (PEC) employing an electrolyte solution with 1.0 M KH2PO4/K2HPO4 buffer. The results demonstrate a substantial photocurrent density of 0.23 mA.cm–2 at a potential of 1.6 V (versus RHE) and a photoconversion efficiency of 0.1% at 0.52 V (vs. RHE), respectively. This pioneering study underscores the potential of Au/TiO2 NP photoanodes as key components in advancing sustainable energy technologies, particularly in the realm of efficient PEC water-splitting applications.
Cauchy matrix approach for generalized semi-discrete lattice potential Korteweg–de Vries equations
Authors: Qiu Siming , Wang Ruodong , Yao Yuqin 
Published: August 2024

Abstract
Starting from a new scattering relation, we generate a generalized semi-discrete lattice potential Korteweg–de Vries(gsd-lpKdV) equation from a determining equation set(DES) and its Lax presentation. Further, the gsd-lpKdV equation with self-consistent sources(gsd-lpKdVSCS) is worked out by introducing two discrete variables to the plane wave factors. Specially, explicit formulae for kink solitons, Jordan-block solutions and diagonal-Jordan-block solutions of gsd-lpKdVSCS are obtained based on the Cauchy matrix approach. Moreover, We illustrate the dynamics of one-kink soliton, two-kink soliton, high order Jordan-block solutions and the diagonal-Jordan-block solution.
Microstructure and high-temperature oxidation resistance of in-situ synthesized Ti-Al-Si composite coating by laser cladding
Authors: Wang Yueyi , Hao Xuanhong , Liu Yaxia , Yang Chen , Liu Hongxi , Zhang Xiaowei 
Published: August 2024

Abstract
According to the in situ reaction mechanism of Ti, Al, Si mixed powders and the Ti-Al-Si ternary phase diagram, two kinds of alloy systems with an atomic ratio of Ti: Al: Si=41:41:18 and Ti: Al: Si=35:35:30 was designed. The Ti-Al-Si composite coatings were in situ synthesized by laser cladding on Ti6Al4V titanium alloy (TC4) surface. The microstructure and phase composition of composite coating were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The microhardness and corrosion resistance of coating were investigated by microhardness tester and electrochemical workstation. The high-temperature oxidation resistance and anti-oxidation mechanism of coating at 800 °C × 24 h × 5 times cyclic oxidation was analyzed by oxidation mass gain and oxidation kinetics curves. The results show that the Ti-Al-Si composite coating has a good metallurgical bonding with titanium alloy substrate. The coating is mainly composed of Ti5Si3, Ti7Al5Si12, Ti3Al, TiAl and TiAl3 phases. The average microhardness of the two kinds of coating is 853.3 HV0.2 and 795.2 HV0.2, 2.37 times and 2.21 times that of the substrate, respectively. Compared with titanium alloy substrate, the corrosion resistance of the coating in artificial seawater has been improved significantly, and the coating with an atomic ratio of Ti: Al: Si=41:41:18 is better than the coating with an atomic ratio of Ti: Al: Si=35:35:30. The oxidation kinetics curves at 800 °C × 24 h × 5 times cyclic oxidation exhibit that the oxidation resistance of Ti: Al: Si=41:41:18 coating increase by 12.5 times. The oxide layer on titanium alloy surface is loose and composed of rod-like TiO2 and cluster islands Al2O3. However, on the surface of cladding composite coating, a uniform, dense and long rod-like oxide layer with a thickness of about 8 μm is formed. The oxide layer on cladding composite coating surface is mainly composed of TiO2, Al2O3 and SiO2. The in situ synthesized Ti-Al-Si laser cladding composite coating plays a positive role in improving the high-temperature oxidation resistance of titanium alloy.