bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Sr substitution on the structural, dielectric and ferroelectric property of BaTiO3
Authors: Yadav Satish , Deshmukh Vaidehi , Tiwari Shivendra , Rawat R , Sathe Vasant , Singh Kiran 
Published: August 2024

Abstract
We have performed a comprehensive study to explore the effect of Sr substitution on the structural and ferroelectric properties of BaTiO3 (BTO) with compositions Ba1-x
Sr
x
TiO3 for 0 ⩽ x ⩽ 1. The room temperature structural investigation inferred that the samples with compositions x > 0.30 has cubic phase instead of tetragonal as for pristine BTO. The temperature dependent dielectric studies illustrate that all well-known three structural phase transitions of BTO are coming closer to each other and the cubic phase is shifted towards lower temperature with increasing Sr content. The frequency dependent dielectric measurements show that there exists the mesoscopic subdomain, whose relaxation time decreases with increasing Sr concentration. The Sr substitution enhanced the ferroelectric properties and maximum remnant polarization at room temperature is observed for 20% Sr substituted sample. The frequency dependent dielectric measurements illustrate the relaxation which could be due to the mesoscopic subdomain, and its relaxation time decreases with increasing Sr concentration. The frequency dependent P–E measurements at room temperature infer that for 30% Sr substituted sample, the ferroelectric domain switching is dominated by the rate of nucleation whereas in other compositions for x < 0.3, it is governed by the domain wall speed. The Raman measurements infer the rearrangement of the domain configuration with Sr substitution. Modification in the intensity of the E(TO4) and A(TO3) Raman modes with electric field is also observed for 30% Sr substituted sample and the origin of this is also discussed.
First-principles calculations to investigate phase stability, elastic and thermodynamic properties of TiMoNbX (X=Cr, Ta, Cr and Ta) refractory high entropy alloys
Authors: Wang Yueyi , Liu Hongxi , Hao Xuanhong , Yang Chen , Liu Yaxia , Chen Lin , Zhang Xiaowei 
Published: August 2024

Abstract
This work uses first-principles calculations to investigate the phase stability, thermophysical and mechanical properties of refractory high entropy alloys (RHEAs) at finite temperatures. On the basis of plane wave quasi-potential and density functional theory, construct the structure model of a solid solution. The TiMoNbX (X = Cr, Ta, Cr and Ta) RHEAs have been determined to preserve a single body-centered cubic solid solution structure by calculations and the equilibrium lattice parameters and elastic modulus are consistent with experimental data obtained by laser cladding, which is combined with TC4 (Ti–6Al–4V) substrate. Using the quasi-harmonic Debye–Grüneisen model, the thermophysical characteristics of three RHEAs are investigated. The Voigt–Reuss–Hill scheme is used for calculating the Young’s modulus (E), bulk modulus (B), shear modulus (G), and Poisson’s ratio (ν), which indicates that all three RHEAs are ductile materials. Additionally, the modulus and hardness of materials decrease as temperature rises, whereas the properties of TiMoNbX RHEAs are predicted, as the nanoindentation hardness values at room temperature are comparable to, and slightly higher than the calculated values.
Thermodynamics and dynamics of coupled complex SYK models
Authors: Louw Jan C , van Manen Linda M , Jha Rishabh 
Published: August 2024

Abstract
It has been known that the large-q complex Sachdev-Ye-Kitaev (SYK) model falls under the same universality class as that of van der Waals (mean-field) and saturates the Maldacena-Shenker-Stanford (MSS) bound, both features shared by various black holes. This makes the SYK model a useful tool in probing the fundamental nature of quantum chaos and holographic duality. This work establishes the robustness of this shared universality class and chaotic properties for SYK-like models by extending to a system of coupled large-q complex SYK models of different orders. We provide a detailed derivation of thermodynamic properties, specifically the critical exponents for an observed phase transition, as well as dynamical properties, in particular the Lyapunov exponent, via the out-of-time correlator calculations. Our analysis reveals that, despite the introduction of an additional scaling parameter through interaction strength ratios, the system undergoes a continuous phase transition at low temperatures, similar to that of the single SYK model. The critical exponents align with the Landau–Ginzburg (mean-field) universality class, shared with van der Waals gases and various AdS black holes. Furthermore, we demonstrate that the coupled SYK system remains maximally chaotic in the large-q limit at low temperatures, adhering to the MSS bound, a feature consistent with the single SYK model. These findings establish robustness and open avenues for broader inquiries into the universality and chaos in complex quantum systems. We provide a detailed outlook for future work by considering the ‘very’ low-temperature regime, where we discuss relations with the Hawking–Page phase transition observed in the holographic dual black holes. We present preliminary calculations and discuss the possible follow-ups that might be taken to make the connection robust.
Image super-resolution reconstruction of vast-receptive-field pixel attention for precision measurement
Authors: Chen Ziyi , Zhang Jin , Sun Zhenxi , Liang Xiaohan , Gao Qiaorong , Xia Haojie 
Published: August 2024

AbstractCompared with traditional contact precision measurement, vision-based non-contact precision measurement has the features of low cost and flexible multi-point information extraction, but how to ensure the measurement accuracy of vision-based non-contact precision measurement is an urgent problem. Traditional thinking often focuses on hardware upgrades to improve image resolution, but this brings high costs and is limited by the physical characteristics of the hardware itself. In this paper, we start from the software aspect to improve the image resolution by using the super-resolution reconstruction algorithm and propose an image super-resolution reconstruction algorithm—Swin Transformer with a Vast-receptive-field Pixel Attention, which combines the vast-receptive-field pixel attention mechanism with the Swin Transformer self-attention mechanism, focuses on the learning of the high-frequency information features of the image. Experiments are conducted both in public datasets and real measurement images. Extensive experimental validation shows that the model can obtain more edge and high-frequency detail features in public datasets, and the objective evaluation index on Set5, Set14, B100, Urban100, and Manga109 datasets is improved by 0.06 dB on average compared with the existing algorithms. In actual measurements, the algorithm in this paper for USAF1951 resolution tablet, image super-resolution reconstruction image in the horizontal and vertical direction of the measurement accuracy increased by an average of 6.97%, the horizontal and vertical direction of the relative measurement accuracy of an average of 30.20% improvement. This study provides a potential development direction for vision-based non-contact precision measurement.
A compound fault diagnosis method for rolling bearings based on the IPSO-MOMEDA and Teager energy operator
Authors: Li Shengqiang , Yan Changfeng , Hou Yunfeng , Wang Huibin , Liu Xiru 
Published: August 2024

Abstract
Different types of faults interact with each other and are easily overwhelmed by strong noise, which makes it challenging to identify and isolate single fault features in rolling bearing compound faults (RBCFs). To address this problem, a diagnosis method for RBCFs with improved particle swarm optimization multipoint optimal minimum entropy deconvolution adjusted (IPSO-MOMEDA) and a Teager energy operator is proposed. The optimal settings for the period and filter length are automatically determined by the excellent optimization capabilities of IPSO, which leads to quick and efficient identification of the global optimum. Moreover, the optimal deconvolution of various fault types is obtained by the optimized MOMEDA. The Teager energy operator is introduced to enhance the shock and periodicity components of the deconvolution signal, which can ensure that the accurate fault period can be selected by MOMEDA. Envelope analysis is employed for identification of compound fault characteristics. Both the simulation and experimental results demonstrate that inner ring and outer ring faults, inner ring and ball faults, outer ring and ball faults, and inner–outer ring and ball faults can be accurately diagnosed using the proposed method.
Large-scale magnetic target state estimation using model parameter optimization
Authors: Lu Binjie , Zhang Xiaobing 
Published: August 2024

Abstract
Improved grey wolf optimizer-conjugate gradient least squares (IGWO-CGLS) algorithm is proposed to solve the state estimation problems of large-scale magnetic target location, target recognition and magnetic moment estimation. To address the state estimation problem of large-scale magnetic targets, a magnetic dipole array magnetic field observation model is established based on a single magnetic vector sensor, and the magnetic target model parameter inversion based on IGWO-CGLS is used to obtain the state of the magnetic target. The state of the target is obtained by inverting the parameters of the magnetic target model. Firstly, the signal preprocessing is carried out by thresholding and down sampling to extract the complete magnetic field passing characteristics, and then the IGWO is used to optimize the magnetic target position, speed, heading and length, and then the magnetic moment parameter is calculated by CGLS to obtain the state parameters of the magnetic target. And numerical experiments are designed to sublicense the influencing factors of state estimation accuracy. The numerical simulation results show that IGWO-CGLS has higher state estimation accuracy than particle swarm optimization-CGLS, artificial hummingbird algorithm-CGLS, artificial rabbits optimization-CGLS, GWO-CGLS, IGWO-stepwise regression. The ship model test results show that IGWO-CGLS can estimate the state parameters of the ship model better.
Advancing oil and gas pipeline monitoring with fast phase fraction sensor
Authors: dos Santos Eduardo Nunes , Reginaldo Natan S , Longo Jean N , da Fonseca Jr Roberto , Conte Marco G , Morales Rigoberto E M , da Silva Marco Jose 
Published: August 2024

Abstract
In the oil and gas sector, the design of monitoring equipment usually prioritizes durability and long-term reliability. However, such equipment does not provide resolution for scientific research, where capturing transient and dynamic events is crucial to enhancing flow understanding. This work describes the development of a capacitive sensor system optimized for phase fraction measurements in oil–gas industrial environments. The sensor features high sensitivity and temporal resolution to meet flow measurement investigative requirements. The measurement technique is based on the electrical capacitance variations of the flowing media and was validated with reference equipment. Six sensors were deployed across multiple test stations to analyze the slug flow regime and its evolution along the pipe. The data collected from these experiments were processed, and flow parameters were compared with a model that describes the elongated bubble shape found in the slug flow pattern. Results show a good agreement between the experimental data and the model, validating its capability to track the fast-changing phases of multiphase flow. The uncertainty analysis revealed a maximum absolute uncertainty of 1.41% for the gas fraction measurements. Further, the gas flow rate was evaluated with a good agreement against the reference gas flow meter, ensuring the sensor’s reliability in dynamic multiphase flow environments. By providing accurate experimental data from real-world industrial conditions, the developed sensor can significantly enhance the precision of flow models, thereby improving the understanding of complex flow phenomena.
Design and characterization of a novel turbidity sensor based on quadrature demodulation
Authors: Tang Bo , Ruan Jiaming , Wang Jie , Yu Zhi , Xu Ming , Cheng Yinbao 
Published: August 2024

Abstract
Turbidity is regarded as a comprehensive indicator in water quality monitoring, and the turbidity sensor deployed in the water supply network can record the dynamic changes of water quality in time. However, the weak photoelectric signal from the photodetector contains a quantity of noise. In order to improve signal-to-noise ratio, a novel on-line turbidity sensor based on quadrature demodulation principle has been proposed in this paper. A near-infrared light-emitting diode (LED) with a wavelength of 860 nm was selected as a stable monochromatic light source, and a photodiode with an angle of 90° to the incident light from the LED was selected as the photodetector. Using signal modulation and demodulation technology, the weak photoelectric signal extraction, conversion, amplification and output of the turbidity sensor were realized through the effective integration. A corresponding test apparatus of the turbidity sensor was established and experimental results showed that within a 0–5 NTU measurement range, the turbidity sensor had good linearity and stability, the relative measurement error was within ±1% and the limit of detection could reach as low as 0.0049 NTU. The developed turbidity sensor has good detection performance and can meet the needs of low turbidity detection of drinking water.
Obtaining and qualitative analysis of time-lagged correlations between seawater quality parameters
Authors: Zhu Qiguang , Shen Zhen , Wu Zhen , Zhang Hongbo , Yuan Junjun , Chen Ying 
Published: August 2024

Abstract
In the regulation of seawater quality, it is crucial to understand the interactions between parameters and the time-lagged effects. This paper focuses on the problem of how to obtain and analyze time-lagged correlations between seawater quality parameters, an issue that has not attracted the attention of researchers. In this paper, a graph neural network-based model, dynamic adjacency weight network, is proposed to model the time-lagged correlation between seawater quality parameters. By regarding the parameters as nodes, the proposed model retains the relationships between the parameters in a weighted adjacency matrix, overcoming the problem of traditional deep neural networks that are difficult to be visualized. Meanwhile, the proposed multivariate multistep shift prediction strategy enables the proposed model to accurately obtain the time-lagged correlation information between parameters at different time intervals. In addition, the proposed model also addresses some of the details worth considering when obtaining correlations between seawater quality parameters. The proposed model performs well in the prediction of water quality parameters. This indirectly verifies the validity of the obtained correlations and overcomes the difficulty of verifying the validity of statistical methods. This study provides new ideas and methods for seawater quality monitoring and research.
Rational construction of dicarbonous CB/CNT@PI composites toward low filler loading and low-frequency electromagnetic wave absorption
Authors: Qiu Hongfang , Cheng Yong , Fang Xiong , Lu Junyu , Di Xiaochuang , Lu Zhao , Chen Yang , Zou Huawei 
Published: August 2024

Abstract
With the application of low frequency radar and the demand for stealth of high temperature resistant components, it is increasingly urgent to develop absorbing materials with both low frequency and high temperature resistant properties. Here, we successfully prepared various carbon/polyimide composites as low-frequency electromagnetic wave (EMW) absorbing materials by simple blending method. The well-designed mesh lap structure introduces a large amount of free space, further optimizing the impedance matching of the material. At the same time, the multiple loss mechanism formed by the combination of carbon black dominated polarization and carbon nanotube dominated conductive loss enhances the loss of incident EMW. The results showed that only 10 wt% filler loading of the CB/CNT@PI is achieved in the low frequency range (1–4 GHz) with a minimum reflection loss strength of –18.3 dB, which has obvious advantages compared with other works in recent years. This study provides a way for the design and preparation of resin-based absorbing materials.
A liquid crystal based non-Hermitian metasurface for broadband full-Stokes polarization detection
Authors: Gao Fan , Han Yufan , Zhao Yujia , Zhou Tao , Deng Juan , Yan Bo 
Published: August 2024

Abstract
The ability to detect the polarization information of light is often crucial for various applications in optical systems. However, conventional polarization-sensitive photodetectors struggle to simultaneously achieve a wide band coverage and high-precision detection, severely hindering the development of polarization detectors. In this study, a reflective metasurface with full-Stokes detection capabilities over a wide range is proposed. It integrates four linear polarization filters and two circular polarization filters operating in the near-infrared region. By dynamically adjusting the refractive index of the liquid crystal covering the detector surface, high performance full-Stokes parameter detection can be achieved between 730–770 nm with detection error below 0.07. Therefore, this study provides a design approach for the potential application of Stokes polarization detection over a broadband spectrum.
Ultrasonic guided wave damage localization method for composite fan blades based on damage-scattered wave difference
Authors: Liu Hailong , Huang Meiao , Zhang Qingchen , Liu Qijian , Wang Yishou , Qing Xinlin 
Published: August 2024

Abstract
Ultrasonic guided wave (UGW) has a wide monitoring range and high accuracy, showing promise for monitoring damage in large-area composite fan blades. However, the multi-curvature characteristics of engine composite fan blades and their anisotropic material properties make damage localization difficult with conventional UGW monitoring methods. In order to realize the UGW damage monitoring of the blade, this paper proposes a damage localization method based on damage-scattered wave differences. This method addresses the challenge of locating damage in multi-curvature composite blades. First, the difference between the mutual excitation in a pair of sensors and the damage-scattered waves captured at reception was analyzed. It is concluded that the closer the damage is to the receiving sensor, the greater the damage index (DI). Next, a DI ratio of the mutually excited and received signals is computed for each sensor pair. This ratio is used to draw a vertical line on the propagation path, identified as the damage likelihood line (DLL). Finally, the DLL corresponding to the three largest DIs is selected, and their intersections were used for damage localization. A time-domain truncated signal processing method is proposed to enable the DI to more accurately represent the effects of damage and improve the localization accuracy of the method. An experiment on damage localization was conducted on a homemade composite fan blade, where the damage was tested at various locations and sizes. The results show that the damage localization on the blade is good and 3 mm tiny damage localization is achieved.
Coulomb excitation of hydrogen atoms by vortex ion beams
Authors: Maiorova A V , Karlovets D , Fritzsche S , Surzhykov A , Stöhlker Th 
Published: August 2024

Abstract
Coulomb excitation of hydrogen atoms by vortex protons is theoretically investigated within the framework of the non-relativistic first–Born approximation and the density matrix approach. Special attention is paid to the magnetic sublevel population of excited atoms and, consequently, to the angular distribution of the fluorescence radiation. We argue that both these properties are sensitive to the projection of the orbital angular momentum (OAM), carried by the projectile ions. In order to illustrate the OAM–effect, detailed calculations have been performed for the

1
s
→
2
p

excitation and the subsequent

2
p
→
1
s

radiative decay of a hydrogen target, interacting with incident Laguerre–Gaussian vortex protons. The calculation results suggest that Coulomb excitation can be employed for the diagnostics of vortex ion beam at accelerator and storage ring facilities.
Disruption runaway electron generation and mitigation in the Spherical Tokamak for Energy Production (STEP)
Authors: Fil A. , Henden L. , Newton S. , Hoppe M. , Vallhagen O. 
Published: August 2024

Abstract
Generation of Runaway Electrons (REs) during plasma disruptions is of great concern for ITER and future reactors based on the tokamak concept. Unmitigated RE generation in the current STEP (Spherical Tokamak for Energy Production) concept design is modelled using the code DREAM, with hot-tail generation found to be the dominant primary generation mechanism and avalanche multiplication of REs found to be extremely high. Varying assumptions for the prescribed thermal quench (TQ) phase (duration, final electron temperature) as well as the wall time, the plasma-wall distance, and shaping effects, all STEP full-power and full-current unmitigated disruptions generate large RE beams (from 10 MA up to full conversion). RE mitigation is first studied by modelling idealised mixed impurity injections, with ad-hoc particle transport arising from the stochasticity of the magnetic field during the TQ, but no combination of argon and deuterium quantities allows runaways to be avoided while respecting the other constraints of disruption mitigation. Initial concept of STEP disruption mitigation system is then tested with DREAM, assuming two-stage shattered pellet injections (SPI) of pure

D

2

followed by Ar+

D

2

. Such a scheme is found to reduce the generation of REs by the hot-tail mechanism, but still generates a RE beam of about 13 MA. Options for further optimising the SPI scheme, for mitigating a large RE beam in STEP (benign termination scheme), as well as estimations of required RE losses during the current quench (from a potential passive RE mitigation coil) will also be discussed.
Research on influence factors of small punch test to evaluate the mechanical properties of gradient nanostructured material
Authors: Yang Xinjun , Liao Xiangwei , Wang Dongxiang , Du Jiyun , Yuan Fangyang , Yu Wei , Li Qingsheng 
Published: August 2024

Abstract
The influence factors of small punch test (SPT) were investigated to evaluate the mechanical properties of gradient nanostructured (GNS) materials. The gradient nanostructure was prepared on the top layer of S30408 austenitic stainless steel by ultrasonic impact treatment (UIT). The mechanical properties of the GNS material were obtained using SPT and correlated with those obtained by standard tensile tests. The results indicate that, when the specimen thickness is 0.5 mm, the sphere diameter is 2.4 mm, the punch velocity is 0.5 mm min−1, and the gradient nano-grained layer is placed face-on in the mold, the GNS material exhibits better plastic deformability. The SPT specimen achieves better bearing capacity, and the mechanical properties of the GNS material obtained by SPT are more accurate. The yield strength and tensile strength of the GNS material were also evaluated by analytical and empirical methods in SPT. The error is approximately 10% compared with the standard tensile test results, which is within the allowable range.