bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bearing fault diagnosis under variable speed conditions on adaptive time frequency extraction mode decomposition
Authors: Huo Jiyuan , Yang Jianwei , Yao Dechen , Sun Runtao , Hu Zhongshuo , Chen Zhiheng , Gao Cheng 
Published: March 2024

Abstract
Improvements in measurement technology have made it possible to detect problems with rolling bearings more accurately, which is important to ensure that they work properly in mechanical systems under different variable speed conditions. Time–frequency distribution (TFD) methods are widely used in variable-speed rolling bearing fault diagnosis, we construct a new method: adaptive time frequency extraction mode decomposition (ATFEMD) by capturing the distinctive time–frequency information within the TFD through ridge extraction, subsequently, the reconstruction components are further refined into adaptive modes through the harmonic detection and noise testing process. This method is a time–frequency post-processing method that effectively solves the problems of time–frequency energy lack of concentration, poor robustness of instantaneous frequency extraction, and mode aliasing in signal decomposition. This article analyzes the simulated bearing vibration and test bench bearing vibration signals to demonstrate the performance of ATFEMD. Results indicated that the proposed method is characterized by strong robustness, and good feature extraction results compared to other methods.
Broadband light absorption by a hemispherical concentric nanoshell array
Authors: Jiang Xiaoyun , Fan Fei , Su Feng , Mu Tianrui , Huang Chan , Zhou Leiming , Hu Jigang 
Published: March 2024

Abstract
Achieving highly efficient broadband absorption is an important research area in nanophotonics. In this paper, a novel method is proposed to design broadband near-perfect absorbers, consisting of a four-layer hemispherical concentric nanoshell array. The proposed nanostructure supports absorptivity exceeding 95% in the entire visible region, and the absorption bandwidth is determined by the interaction or ‘hybridization’ of the plasmons of the inner and outer metal-based nanoshells. Moreover, the designed absorber has wide-angle capability and is insensitive to polarization. The simple structure, as well as the stable absorption properties, suggests that such core–shell nanostructures can serve as a potential candidate for many applications such as solar energy harvesting, photo-detection, and emissivity control.
Maximum a posteriori detection of heartbeats from a chest-worn accelerometer
Authors: Schipper Fons , van Sloun Ruud J G , Grassi Angela , Brouwer Jan , van Meulen Fokke , Overeem Sebastiaan , Fonseca Pedro 
Published: March 2024

Abstract

Objective. Unobtrusive long-term monitoring of cardiac parameters is important in a wide variety of clinical applications, such as the assesment of acute illness severity and unobtrusive sleep monitoring. Here we determined the accuracy and robustness of heartbeat detection by an accelerometer worn on the chest. Approach. We performed overnight recordings in 147 individuals (69 female, 78 male) referred to two sleep centers. Two methods for heartbeat detection in the acceleration signal were compared: one previously described approach, based on local periodicity, and a novel extended method incorporating maximum a
posteriori estimation and a Markov decision process to approach an optimal solution. Main results. The maximum a
posteriori estimation significantly improved performance, with a mean absolute error for the estimation of inter-beat intervals of only 3.5 ms, and 95% limits of agreement of −1.7 to +1.0 beats per minute for heartrate measurement. Performance held during posture changes and was only weakly affected by the presence of sleep disorders and demographic factors. Significance. The new method may enable the use of a chest-worn accelerometer in a variety of applications such as ambulatory sleep staging and in-patient monitoring.
Electrical, optical and mechanical properties of monolayer MoTe2 for applications in wearable optoelectronic devices
Authors: Zhang Zhekai , Zhao Tian-Long , Ma Xiangchao , Zhao Zihan , Jian Chaochao , Dai Xianying , Song Jianjun 
Published: March 2024

Abstract
Transition metal dichalcogenides (TMDs) have excellent optical and mechanical properties and have potential application value in wearable optoelectronic response devices. MoTe2, a representative material of TMDs, is studied by first-principles calculation in this paper. The results show that the MoTe2 monolayer has a direct band gap of 1.110eV, which has a strong light absorption capacity and can produce a high concentration of photogenerated charge carriers after light absorption. The material is soft and exhibits the unique mechanical properties of layered materials. The effects of biaxial strain and defects on the properties of the materials were analyzed. The results show that the biaxial compression strain can enhance the light absorption curve of the material, enhance the light absorption of the photogenerated carrier, and expand the range of its energy distribution. The tensile strain decreases the value of the photon absorption curve and decreases the range of energy distribution of photogenerated carriers. The Mo vacancy defect increases the absorption curve value in the low energy region and broadens the optical response range of the material. The two types of vacancy defects both induce a ‘discrete’ distribution of photogenerated carriers. The Mo vacancy significantly affects the elastic modulus and anisotropy properties of the material, resulting in the material changing from ductile to brittle. When Mo vacancy is added, the spatial distribution of the elastic modulus of the material also changes greatly. Therefore, MoTe2 has potential application in flexible optoelectronic devices, and its performance can be controlled by strains and defects.
Generating superposition of squeezed states and photon-added squeezed states
Authors: Bohloul M , Dehghani A , Fakhri H 
Published: March 2024

Abstract
The scheme of an arrangement is considered for the preparation of some non-classical superposed states from squeezed states by using the optical parametric amplifier (OPA) apparatus, which is based on an idea recently proposed to generate photon-added states from the coherent states of light. This technique allows one to obtain linear combinations of squeezed vacuum states (SVSs) and n-photon-added squeezed vacuum states (n-PASVSs), that can enrich the non-classicality of the SVSs and n-PASVSs and improve their performances in quantum information protocols. Their characteristics are greatly affected by the gain of the OPA and the coherent field amplitude (or, mean number of photons). For this purpose, a comprehensive analysis of the non-classical features of these states has been presented in four different behavioral regimes, i.e. low- and high-gain regimes in the presence of weak and strong coherent fields. Finally, the role of the gain parameter of the light state from OPA as one of the input states of the Mach–Zehnder interferometer (MZI) apparatus in phase sensitivity optimization is discussed.
Exact Green’s function for 2D dirac oscillator in constant magnetic field within curved snyder space, and its thermal properties
Authors: Benzair Thouiba , Chohra Thouraia , Boudjedaa Tahar , Merad Mahmoud 
Published: March 2024

Abstract
Following the path integral approach, and in the context of curved Snyder space, we formulate the Green function for a (1+1)-dimensional Dirac oscillator system subject to a homogeneous magnetic field. Using the radial coordinates transformation the Green function and the electron propagator are calculated. Consequently, the exact bound states and their corresponding spectral energies are extracted. Our analysis has revealed that, under specific conditions when

m

ω

¯

→
m

ω

c

/

2

and c → V

F
, the behavior of the Dirac oscillator system in the presence of a uniform magnetic field within the SdS algebra closely resembles the dynamics of the monolayer graphene problem in the same algebraic framework. At high temperatures, the thermodynamic properties of the electron gas in the four cases of deformation parameters were extracted. The effect of the deformation parameters on these properties are tested, and also the limit cases for small parameters were inferred.
Superdeformation and dynamical symmetry
Authors: Riczu G , Darai J , Cseh J 
Published: March 2024

Abstract
Superdeformed bands are determined from symmetry-considerations, and their in-band E2 transition strengths are predicted. Those light nuclei are studied which were investigated from the experimental side, and comparison can be made with observed data. The SU(3) symmetry seems to organize the experimental finding to a good approximation.
Ion-acoustic solitary waves in Mars’ lower ionosphere
Authors: Elgohary Hala E , Farag Omar F , Moslem Waleed M 
Published: March 2024

Abstract
This study suggests that ionic species dynamics generate electrostatic ion-acoustic solitary waves (IASWs) in Mars’ lower ionosphere. It has been determined through observations that the lower ionosphere of Mars, specifically between 200 and 350 km above the surface, is mostly made up of ions like

O

2

+

, O
+, and

CO

2

+

, along with superthermal electrons. This study investigates the occurrence, propagation, and properties of IASWs. The derivation of the evolution equation is conducted for waves with a small-but-finite-amplitude. In order to analyze IASWs with large amplitude, the Sagdeev pseudo-potential is obtained. The model predicts the propagation of electrostatic IASWs within an electric field range of 1 to 6 mV/m and a pulse duration period of 0.5 to 4 ms. Fast Fourier analysis of the electric field pulse reveals pulses from 0.8 to 4 kHz.
Effects of caudal fin stiffness on optimized forward swimming and turning maneuver in a robotic swimmer
Authors: Deng Hankun , Li Donghao , Panta Kundan , Wertz Andrew , Priya Shashank , Cheng Bo 
Published: March 2024

Abstract
In animal and robot swimmers of body and caudal fin (BCF) form, hydrodynamic thrust is mainly produced by their caudal fins, the stiffness of which has profound effects on both thrust and efficiency of swimming. Caudal fin stiffness also affects the motor control and resulting swimming gaits that correspond to optimal swimming performance; however, their relationship remains scarcely explored. Here using magnetic, modular, undulatory robots (μBots), we tested the effects of caudal fin stiffness on both forward swimming and turning maneuver. We developed six caudal fins with stiffness of more than three orders of difference. For a μBot equipped with each caudal fin (and μBot absent of caudal fin), we applied reinforcement learning in experiments to optimize the motor control for maximizing forward swimming speed or final heading change. The motor control of μBot was generated by a central pattern generator for forward swimming or by a series of parameterized square waves for turning maneuver. In forward swimming, the variations in caudal fin stiffness gave rise to three modes of optimized motor frequencies and swimming gaits including no caudal fin (4.6 Hz), stiffness <10−4 Pa m4 (∼10.6 Hz) and stiffness >10−4 Pa m4 (∼8.4 Hz). Swimming speed, however, varied independently with the modes of swimming gaits, and reached maximal at stiffness of 0.23 × 10−4 Pa m4, with the μBot without caudal fin achieving the lowest speed. In turning maneuver, caudal fin stiffness had considerable effects on the amplitudes of both initial head steering and subsequent recoil, as well as the final heading change. It had relatively minor effect on the turning motor program except for the μBots without caudal fin. Optimized forward swimming and turning maneuver shared an identical caudal fin stiffness and similar patterns of peduncle and caudal fin motion, suggesting simplicity in the form and function relationship in μBot swimming.
Long-term observation of polycaprolactone small-diameter vascular grafts with thickened outer layer and heparinized inner layer in rabbit carotid arteries
Authors: Xiao Yonghao , Jin Xin , Jia Liujun , Li Jubo , Zhang Baojie , Geng Xue , Ye Lin , Zhang Ai-ying , Gu Yongquan , Feng Zeng-guo 
Published: March 2024

Abstract
In our previous study, the pristine bilayer small-diameter in situ tissue engineered vascular grafts (pTEVGs) were electrospun from a heparinized polycaprolactone (PCL45k) as an inner layer and a non-heparinized PCL80k as an outer layer in the thickness of about 131 μm and 202 μm, respectively. However, the hydrophilic enhancement of inner layer stemmed from the heparinization accelerated the degradation of grafts leading to the early formation of arterial aneurysms in a period of 3 months, severely hindering the perennial observation of the neo-tissue regeneration, host cell infiltration and graft remodeling in those implanted pTEVGs. Herein to address this drawback, the thickness of the outer layers was increased with PCL80k to around 268 μm, while the inner layer remained unchangeable. The thickened TEVGs named as tTEVGs were evaluated in six rabbits via a carotid artery interpositional model for a period of 9 months. All the animals kept alive and the grafts remained patent until explantation except for one whose one side of arterial blood vessels was occluded after an aneurysm occurred at 6 months. Although a significant degradation was observed in the implanted grafts at 9 month, the occurrence of aneurysms was obviously delayed compared to pTEVGs. The tissue stainings indicated that the endothelial cell remodeling was substantially completed by 3 months, while the regeneration of elastin and collagen remained smaller and unevenly distributed in comparison to autologous vessels. Additionally, the proliferation of macrophages and smooth muscle cells reached the maximum by 3 months. These tTEVGs possessing a heparinized inner layer and a thickened outer layer exhibited good patency and significantly delayed onset time of aneurysms.
The impact of tropical sea surface temperature on extreme precipitation in Pakistan during the summer of 2022
Authors: Luo Yulan , Liu Lin , Zhang Yun , Mehmood Shahbaz , Yang Yang , Yang Guang , Duan Yongliang , Li Qiuchi , Zeng Ai , Yu Weidong 
Published: March 2024

Abstract
In August 2022, Pakistan experienced an unprecedented precipitation event that caused significant damage. Analysis of the observations reveals that this extreme rainfall is primarily driven by anomalous atmospheric zonal advection, resulting in an anomalous water vapor concentration in Pakistan. The climatological meridional advection also contributes to this flooding. Anomalous easterly winds and low-level vertical convection combine to be critical factors contributing to the moisture concentration over the country. Further investigation identifies the air-sea interaction over the tropical Indian Ocean and abnormal warming over the Arabian Sea are crucial factors influencing this extreme flooding event. The concurrent occurrence of a negative Indian Ocean Dipole event and the warming sea surface temperature anomalies in the northern Arabian Sea intensifies the easterly winds over Pakistan, helping to transfer the anomalous water vapor from the remote region into Pakistan, ultimately contributing to the extreme flooding in 2022.
Wide-angle and Fano-shape contrast between emission and absorption in hybrid polariton-involved planar structure
Authors: Qian Liming , Xu Sicheng , Ye Jingfei , Pei Shixin , Zheng Gaige 
Published: March 2024

Abstract
Nonreciprocal light propagation in planar structure has become a hot topic because of the pattern-free fabrication process and the potentials for exploring heat transfer and energy management. An effective strategy incorporated with natural van der Waals material (α-phase molybdenum trioxide, α-MoO3), ultra-thin polar crystal (silicon carbide, SiC) thin film and a Weyl semimetal interlayer sitting on a metal (silver, Ag) substrate is proposed. The emission and absorption of the suggested device is explored with electromagnetic simulations that utilize the

4
×
4

transfer matrix method. Angular-resolved emission shows that the Fano-shape of nonreciprocity can be maintained within wide angle range. Tunable Fano resonances with different line shapes are demonstrated by varying the structural parameters. Moreover, the enhanced nonreciprocal radiation effect can be observed for both s- and p-polarized incidence waves. The proposal allows simultaneous control of spectral distribution and polarization of radiation, which will facilitate the active design and application of mid-infrared emitters.
Probing electron–phonon coupling in magnetic van der Waals material NiPS3: A non-magnetic site-dilution study
Authors: Pistawala Nashra , Kumar Ankit , Negi Devesh , Rout Dibyata , Harnagea Luminita , Saha Surajit , Singh Surjeet 
Published: March 2024

Abstract
NiPS3 is a van der Waals antiferromagnet which has been shown to exhibit spin-phonon and spin-charge coupling in the antiferromagnetically ordered state below TN = 155 K. It is also a rare Ni-based negative charge-transfer-type insulator with Ni valence in a linear superposition state

ψ
=

α

d
8

+

β

d
9

L

−

+

γ

d

10

L

−

2

, where

L

−

is the ligand hole. Here, we study high-quality single-crystals of Ni1−x
Zn
x
PS3 (0 < x < 0.2) using temperature-dependent specific heat and Raman spectroscopy probes. We show that in pristine NiPS3, the phonon mode at 176 cm−1 (P2), associated with the vibrations of Ni ions, exhibits a distinct Fano asymmetry. The Fano resonance is particularly pronounced in the paramagnetic phase above TN, which was further confirmed by temperature dependent Raman data on the Zn-doped crystals. In the Zn-doped crystals, while the magnetism weakens following the mean-field prediction for site-dilution in a honeycomb lattice, the Fano coupling

|

1

/

q

|

strengthens, increasing monotonically with increasing Zn-doping. The x-ray photoemission spectra suggest an increase in the weight of the

d
9

and

d

10

components in the Zn-doped crystals. These observations indicate the presence of strong electron–phonon coupling in Ni1−x
Zn
x
PS3, in addition to the spin-phonon, and spin-charge coupling previously reported.
Effect of Ni element on microstructure and properties of cold-rolled 316 L austenitic stainless steel
Authors: Zhang Xin , Xiao Yao , Cai Yangchuan 
Published: March 2024

Abstract
In this current investigation, the impact of Nickel (Ni) on the microstructural attributes and properties of a cold-rolled 316 L sheet was examined. The microstructure and phase configuration of austenitic stainless steels, specifically 316 L and 316LNi, were meticulously characterized through the utilization of metallography, X-ray Diffraction (XRD), and Electron Backscatter Diffraction (EBSD) techniques. Subsequent assessments were conducted to evaluate magnetic characteristics, microhardness, and tensile properties. The phase structure of both austenitic stainless steels conforms to a Face-Centered Cubic (FCC) crystal lattice, whereby the grain content oriented along the (110) plane progressively escalates with augmenting degrees of cold rolling. The magnetic conductivity of these austenitic stainless steels satisfactorily adheres to established standards. The incorporation of Nickel (Ni) into the alloy composition enhances the cold deformation capacity of 316 L stainless steel. However, substantial plastic deformation yields heightened dislocation density, thereby promoting enlarged grain dimensions upon solution treatment. Throughout subsequent cold rolling deformation sequences, the augmented grain size observed in 316LNi stainless steel leads to a reduction in dislocation density within the equivalently ordered cold-rolled plate. Simultaneously, this augmented grain size engenders a decline in grain boundary content coupled with an augmentation in twin content. Consequently, the interplay of grain coarsening, diminished dislocation density, and twin-induced softening collectively bestows upon 316LNi stainless steel a lower tensile strength compared to 316 L stainless steel, albeit accompanied by heightened plasticity.
Microstructure and mechanical behaviors of Gasar porous Cu/G4335V steel joint brazed by Ag-28Cu-0.75Ni alloy
Authors: Zhang Haiyan , Xia Chenping , Wang Dong , Yao Yangwu , Li Zaijiu , Xia Fengling 
Published: March 2024

Abstract
Cu/steel composites have the advantages of low cost and high heat dissipation performance, which make them ideal materials for applications in the industrial heat dissipation field. Because of the unique pore structure, the Gasar porous Cu is more excellent in heat transfer performance. However, systematic research still needs to be done on the joining technologies of Gasar porous Cu/steel. In this paper, Gasar porous Cu was joined to G4335V steel using Ag-28Cu-0.75Ni. The microstructure, shear strength, and fracture behavior of the Gasar porous Cu/G4335V steel joint were investigated. The results show that a clear interface of the brazed joint and no brazing defects were found. The joint microstructure mainly comprises α-Cu (ss.), β-Ag (ss.), and Ag-Cu eutectic phase. As the pore diameter of Gasar porous Cu increased, the joining area of the Gasar porous Cu/G4335V steel joint became larger, thereby improving the shear strength of the joint. For the same pore diameter, the shear strength of the mode 1 joint (The load direction and the pore direction are parallel to each other. The pore direction refers to the growth direction of the pore.) was higher than that of the mode 2 joint (The pore direction and the load direction are perpendicular to each other). The fracture analysis indicated that the joint crack was initiated in α-Cu (ss.) and propagated along the banded α-Cu (ss.). The joint fracture was a mixed fracture mechanism that combined ductile-brittle fractures.
Experimental optimization of machining GH4145 by atomizing discharge ablation milling
Authors: Tian Changliu , Li Yanan , Zhuo Xianghua 
Published: March 2024

Abstract
Atomizing discharge ablation milling (ADAM) technology is an efficient discharge machining technology derived from the traditional electrical discharge machining (EDM) method, which can be used to efficiently machine hard-to-machine materials such as nickel-based superalloy. In this present, the performance of machining nickel-based superalloy GH4145 by ADAM and Air near-dry EDM were compared, and the experimental results showed that the material removal rate (MRR) obtained by ADAM was nearly double that of the latter. A single-factor experiment were conducted to investigate the effect of electrode rotation speed on ADAM’s processing performance. Subsequently, an orthogonal experimental method was used to design the experiment. The signal-to-noise ratio analysis method was used to systematically study the performance characteristics of ADAM, including the influence of atomization amount, oxygen pressure, discharge current, duty ratio on MRR and tool electrode relative wear rate (TWR). The results showed that discharge current was the most influential processing parameter on MRR and TWR. Finally, the optimal combination of processing process parameters that met the requirements of various processing effect evaluation indicators were obtained and the correctness of the single objective optimization results was verified through experiments.