bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the influence of nitrogen doping on magnetic anisotropy in CoFe/MgO thin films with different deposition sequences
Authors: Liu Chuyue , Xu Xiulan , Liu Jintao , Yang Xinyan , Zhao Di , Zuo Minggao , Hu Wangyang , Ma Xujie , Yu Guanghua 
Published: September 2024

Abstract
The ferromagnetic (FM)/MgO structure multilayers with perpendicular magnetic anisotropy (PMA) play a crucial role in magnetic random-access memory. It is essential to explore the methods for modulating magnetic anisotropy and to clarify the underlying mechanisms. We study the regulation of the magnetic anisotropy with nitrogen (N) doping concentration (CN) in two samples: Ta/CoFe(N)/MgO/Ta (S1) and Ta/MgO/CoFe(N)/Ta (S2) with different deposition sequences. The S1 sample exhibits in-plane magnetic anisotropy (IMA) without N doping. And the sample presents PMA when CN = 15%. The S2 sample shows weak PMA without N doping, and the sample converts to IMA when CN = 15%. X-ray photoelectron spectroscopy is performed to evaluate the oxidation level of Fe at the CoFe/MgO interface by the peak area ratio of Fe oxide to Fe (ϵ). It is believed that excessively high and low ϵ values correspond to over-oxidation and under-oxidation of Fe, respectively. For films deposited in different sequences, both over-oxidation and under-oxidation lead to IMA, while moderate oxidation facilitates the formation of PMA. The microstructure analysis reveals that the N doping does not affect the crystallization of the films, indicating that magnetocrystalline anisotropy has a minor influence on the changes of K
eff.
Bandgap tuning for transition metal oxides via PEGylation
Authors: Jha Priyanka A , Mishra Jay N , Yadav Gargi , Kumar Tanti Harinder , Ranjan Ashish K , Jha Pardeep K , Singh Prabhakar 
Published: September 2024

Abstract
Bandgap engineering is controlled manipulation of the bandgap of materials/meta-materials to achieve desired properties. The electrical and optical properties of materials are significantly affected by bandgap tuning; therefore, bandgap engineering is a powerful technique for designing electronic and optoelectronic devices. Compositional engineering, strain engineering, and nanoscience and technology are the three major fields associated with bandgap engineering. Any unique combination of this engineering can provide novel strategies to produce novel band-structured devices. In this method article, we have demonstrated how solvation energy can alter the bandgap energy, a fact that is generally ignored due to misconceptions about quantum/size confinement. Here, we prepare nanostructured transition metal oxides (Co3O4, CuO, and ZnO) with polyethylene glycol (PEG), and the method is termed PEGylation. We investigate the influence of PEGylation on the structural, electrochemical, and electronic nature of these oxides. It is observed that the bandgap tunability (7.33%) is maximum for ZnO. Our study suggests that band alteration is significantly correlated with the change in lattice parameters; however, it is orientation dependent as the correlation coefficient reduces to 0.85 from 1 for the change in lattice parameter b along the y-axis compared to the other two lattice parameters. Similarly, band alteration is also known to have some correlation with the electrochemical potential, but is surprisingly almost independent of size confinement.
Comparison of the transportation of reactive species from He and Ar atmospheric-pressure plasma jets to aqueous solutions
Authors: Liu Yifan , Peng Wenyi , Liu Dingxin , Fu Feng 
Published: September 2024

Abstract
In this study, the transportation of reactive species from argon (Ar) and helium (He) atmospheric-pressure plasma jets (APPJs) to water is comparatively investigated using two-dimensional (2D) fluid models. For the same gas flow rate and reactive species concentration at the jet orifice, the transportation efficiency of the Ar APPJ is found to be higher than that of the He APPJ by 3.7 times. This is primarily attributed to the difference in the gas flow between the Ar and He APPJs. Ar has a higher molecular weight than air, which allows the reactive species in the Ar gas flow to sufficiently contact the water surface. He is much lighter than air, and consequently, the He gas flow floats upwards and inhibits transportation. Increasing the gas flow rate can reduce the floating of He and enhance the transportation of all reactive species in the He APPJ, but can only improve the transportation of short-lived species in the Ar APPJ. The use of shielding air gas reduces the floating of He and promotes the production of reactive species in the plasma plume, thus, the normalised concentration of the reactive species in the He APPJ-treated water increases drastically by 30.3 times. The numerical results conform to the trends observed in the available experimental data, which explains the reason why the Ar APPJ has stronger sterilization and anticancer effects than the He APPJ. The findings also serve as a reference for improving the He APPJ for biomedical applications.
Surface acoustic wave amplification by drifting electrons in semiconducting epitaxial graphene on silicon carbide
Authors: A Margulis Vl , Muryumin E E 
Published: September 2024

Abstract
A theory is presented for the amplification of a surface acoustic wave (SAW) due to its interaction with conduction electrons in gate-controlled epitaxial graphene (epigraphene) on a SiC substrate. It is assumed that the SAW is launched onto the substrate in the direction of an external dc electric field applied to the graphene sample and causing the conduction electrons to drift at a speed greater than the speed of the SAW. The wavelength of the SAW is assumed to be shorter than the mean free path of the electrons, so that the quantum regime of interaction of those electrons with the SAW is realized. The Green’s function method is used to calculate the SAW gain as a function of the electron concentration in epigraphene and the external dc electric field strength. It is shown that the substrate-induced band gap in the electronic spectrum of epigraphene leads to a significant (at least an order of magnitude) increase in the SAW gain as compared to the case of gapless graphene. In addition, the opening of the band gap results in a non-monotonic dependence of the SAW gain on the electron concentration, controlled by the gate voltage applied to the graphene sample. This dependence is characterized by the presence of a distinct maximum at a certain value of electron concentration (of about

2
×

10

12

cm−2 for typical values of the other parameters involved), which distinguishes it from the monotonic concentration dependence of the SAW gain in gapless graphene.
Wide-angle low-scattering transmitarray antenna based on transmit-reflect selective metasurface
Authors: Wu Zonghuan , Chen Ke , Zhao Junming , Jiang Tian , Feng Yijun 
Published: September 2024

Abstract
A high-gain transmitarray antenna with low radar cross section (RCS) properties is presented in this paper. Compared with conventional high-profile multilayer designs, we introduce a transmit-reflect selective metasurface integrated with high-gain transmission and random scattering functions, achieving a reduced thickness of 0.13 λ
0 (where λ
0 is the wavelength at the center frequency). For the meta-atom design, we combine geometric rotation and dimension optimization to realize 1-bit independent transmit and reflection phase modulation, respectively. Moreover, in metasurface coding strategy, we employ an initial phase optimization method and a simulated annealing algorithm to determine the optimal coding matrices. The experimental results demonstrate high-performance radiation characterized by the peak gain of 23.6 dB, maximum aperture efficiency of 28.5%, and 3 dB gain bandwidth of 18.4%. For x-polarization, measured 10 dB RCS reduction bandwidth under transverse magnetic (TM) 0°-45° and transverse electric (TE) 0°-20° incidence are 9.02–11.36 GHz. For y-polarization, 10 dB RCS reduction bandwidth under TM 0–60° and TE 0–30° incidence is 8.82–10.96 GHz.
Serial association of dielectric barrier discharge and gliding arc systems: a novel approach for plasma-activated saline production
Authors: Azevedo Neto Nilton F , Miranda Felipe S , Junior Pedro W P Moreira , Gomes Marcelo P , Alves-Junior Clodorimo , Koga-Ito Cristiane Y , Pessoa Rodrigo S 
Published: September 2024

Abstract
Plasma-activated saline (PAS) holds immense potential for diverse applications, including antimicrobial activity, anti-inflammatory effects, and cancer therapy. This study introduces a novel approach utilizing a serially associated hybrid plasma discharge system, which combines dielectric barrier discharge (DBD) with a gliding arc plasma jet (GAPJ), to enhance the production of reactive oxygen and nitrogen species (RONS) in saline water. The serial configuration of DBD and GAPJ effectively amplifies the generation of RONS, as confirmed by optical emission spectroscopy, which revealed unique emissions associated with nitrogen and oxygen ions. Significant changes in the physicochemical properties of saline were observed, including reductions in pH and increases in oxidation–reduction potential and total dissolved solids, particularly during the initial activation phase. Real-time UV–Vis spectroscopy revealed the formation of key RONS such as hydrogen peroxide (H2O2), ozone (O3), nitrite (NO2
‒), and nitrate (NO3
‒), with distinct absorption bands emerging in the UV region. Raman spectroscopy further confirmed the impact of plasma treatment on the molecular structure of saline, showing a weakening of the hydrogen-bonding network. This work offers new insights into PAS production using the serial association of DBD and GAPJ, advancing its potential for various therapeutic applications.
Spatter feature-based in-situ identification of disturbances in process parameters during laser powder bed fusion
Authors: Cao Longchao , Li Weihong , Zhang Yahui , Cai Wang , Wang Zhen , Guo Wentao , Zhou Qi 
Published: September 2024

Abstract
Laser powder bed fusion (LPBF) is one of the most precise and optimal technologies for achieving superior comprehensive performance in metal additive manufacturing. However, the inherent complexity of the laser and material interaction process poses significant challenges to achieving high reliability and precision in part production. Fluctuations in process parameters are one of the main causes of instability and part quality during the LPBF process. Existing research indicates that spatters are closely related to process parameters and the stability of the molten pool. In this paper, we design a high-speed camera system to monitor the spatters, enabling the detection of disturbances in process parameters. A series of experiments with 10 sets of different process parameters are conducted. To effectively extract representative spatter features from captured images, a DeepSort algorithm-based method is proposed. Seven-dimensional features of spatters, including area, perimeter, height, width, speed, angle, and distance from the melt pool to spatters, are extracted to represent spatter characteristics. We further explore the relationships between extracted spatter features and process parameters to verify their rationality in identifying disturbances in process parameters. The results demonstrate that extracted spatter features can effectively represent spatter characteristics and have a high sensitivity in identifying and tracking small spatters. The extracted features are utilized as inputs for a convolutional neural network, achieving a promising accuracy rate of 96.58% for classifying process parameters in the LPBF process. This work demonstrates the feasibility of utilizing spatter features to monitor process parameter fluctuations, enhancing process control and quality assurance in LPBF.
Bearing fault diagnosis by sparse frequency spiral spectrum driven NAF-LDM under strong noise and small samples
Authors: Li Zhixing , Li Tianhao , Wang Yanxue , Pang Yudong , Qiao Zijian 
Published: September 2024

Abstract
The complexity of background noise and the scarcity of real fault samples seriously affect the diagnostic accuracy of the model. To address this, a noise-robust two-dimensional feature map, the sparse frequency spiral spectrum (SFSM), based on sparse representation theory, is proposed. A bridge penalty coefficient is applied to the sparse representation model to accurately select impact components, and the fast iterative shrinkage threshold algorithm is used to solve for sparse representation coefficients. Sparse reconstructed signals are obtained by convolving the impact patterns with these coefficients, leading to a sparse reconstruction algorithm with reduced computational complexity. Furthermore, the novel non-linear activation-free blocks (NAF Blocks) are embedded into the latent diffusion model to augment small samples, significantly improving image generation speed and quality. The integration of the Swin transformer for feature extraction and classification further enhances diagnostic performance. The superiority of this method is validated on the XJTU-SY dataset, a bearing experimental platform dataset, and enterprise engineering dataset. Experimental results demonstrate that the structural and generalization advantages of NAF Blocks are crucial for improving image quality and inference speed. The noise suppression capability of the proposed method, facilitated by the SFSM feature processing technique, is confirmed through ablation and noise robustness tests. Finally, the Swin transformer’s excellent feature extraction and classification capabilities for SFSM are verified. The proposed method achieves diagnostic accuracies of 99.10% and 98.7% on the XJTU-SY and experimental platform datasets, respectively.
Enhanced velocity and weight-bearing capability of piezoelectric viscous-slip actuators utilising a pentagonal flexible hinge configuration
Authors: Qu Wen , Bian Donglong , Li Xingxiang , Zhu Wantao , Ma Rui , Wang Yuhang , Zhang Tao 
Published: September 2024

Abstract
This research presents a novel piezoelectric stick–slip actuator design that capable of achieving higher speeds and handling heavier loads. This addresses the requirement for improved performance in the precision engineering industry. The symmetrical configuration of the pentagonal displacement amplification flexible hinge structure produces the transverse motion. The pentagon’s deformable range is sufficiently broad to amplify the piezoelectric stack’s output displacement and convert it into the desired transverse output displacement. To enhance the load capacity of the piezoelectric stick–slip actuator, one can raise the coupling displacement of the driving foot output. The flexible hinge construction undergoes finite element analysis, and the simulation results meet the design assumptions. The structure has been enhanced to mitigate the potential occurrence of jamming. A prototype was constructed and subjected to rigorous testing to examine its performance. The testing results indicate that the highest attainable velocity is 15.8 mm s−1, with an impressive precision of 35.9 nm. Despite being subjected to a load of 308 g, the output displacement remains steady at 0.376 mm s−1. A comparative study of experimental and finite element simulation findings demonstrates the feasibility of the structural design.
Supercontinuum generation from silver nano species embedded sodium antimony zinc borate glass matrices
Authors: Samuel Alan B , Kumar V V Ravi Kanth , Nalam Samuel Anurag , Harsha S Sree , Kiran P Prem 
Published: September 2024

Abstract
Glass composites that contain metal nanostructures exhibit improved nonlinear properties and ultrafast responses due to their inherent local field effects. In this work, we synthesized glass matrices embedded with diverse silver nano species through the ion exchange method and investigated the generation of supercontinuum from these composites. The formation of silver nano species and their volume fraction were analyzed using the XPS analysis, and their contribution towards supercontinuum broadening was studied. The size of a nanoparticle influences the electron–electron scattering and the frequency of acoustic breathing rate, which influences the extent of supercontinuum broadening. The result indicates the possibility of tuning the nonlinear response of glass nanocomposites by varying the volume fraction of Ag+ and Ag°.
Information theoretic measures on quantum droplets in ultracold atomic systems
Authors: Siddik Sk , Ali Sekh Golam 
Published: September 2024

Abstract
We consider Shannon entropy, Fisher information, Rényi entropy, and Tsallis entropy to study the quantum droplet phase in Bose–Einstein condensates. In the beyond mean-field description, the Gross–Pitaevskii equation with Lee-Huang-Yang correction gives a family of quantum droplets with different chemical potentials. At a larger value of chemical potential, quantum droplet with sharp-top probability density distribution starts to form while it becomes flat top for a smaller value of chemical potential. We show that entropic measures can distinguish the shape change of the probability density distributions and thus can identify the onset of the droplet phase. During the onset of droplet phase, the Shannon entropy decreases gradually with the decrease of chemical potential and attains a minimum in the vicinity where a smooth transition from flat-top to sharp-top QDs occurs. At this stage, the Shannon entropy increases abruptly with the lowering of chemical potential. We observe an opposite trend in the case of Fisher information. These results are found to be consistent with the Rényi and Tsallis entropic measures.
Task-guided attention increases non-linearity of steady-state visually evoked potentials
Authors: Harel Asaf , Shriki Oren 
Published: September 2024

Abstract

Objective. Attention is a multifaceted cognitive process, with nonlinear dynamics playing a crucial role. We investigated the involvement of nonlinear processes in top–down visual attention. Approach. The research paradigm employed a contrast-modulated sequence of letters and numerals, encircled by a consistently flickering white square on a black background—a setup that generated steady-state visually evoked potentials. Nonlinear processes are recognized for eliciting and modulating the harmonics of constant frequencies. Using the rhythmic entrainment source separation technique, we examined the fundamental and harmonic frequencies of each stimulus to evaluate the underlying nonlinear dynamics during stimulus processing. Main results. In line with prior research, our findings indicate that the power spectrum density of electroencephalogram responses is influenced by both task presence and stimulus contrast. We discovered that actively searching for a target within a letter stream heightened the amplitude of the fundamental frequency and harmonics related to the background flickering stimulus. While the fundamental frequency amplitude remained unaffected by the stimulus contrast, a lower contrast led to an increase in the second harmonic’s amplitude. We assessed the relationship between the contrast response function and the nonlinear-based harmonic responses. Significance. Our findings contribute to a more nuanced understanding of the nonlinear processes impacting top–down visual attention.
Real-time equilibrium reconstruction by multi-task learning neural network based on HL-3 tokamak
Authors: Zheng G.H. , Yang Z.Y. , Liu S.F. , Ma R. , Gong X.W. , Wang A. , Wang S. , Zhong W.L. 
Published: September 2024

Abstract
A neural network model, EFITNN, has been developed capable of real-time magnetic equilibrium reconstruction based on HL-3 tokamak magnetic measurement signals. The model processes inputs from 68 channels of magnetic measurement data gathered from 1159 HL-3 experimental discharges, including plasmas current, loop voltage, and the poloidal magnetic fields measured by probes. The outputs of the model feature eight key plasmas parameters, alongside high-resolution (

129
×
129

) reconstructions of the toroidal current density

J

P

and poloidal magnetic flux distributions Ψ

rz
. Moreover, the network’s architecture employs a multi-task learning structure, which enables the sharing of weights and mutual correction among different outputs, and leads to increase the model’s accuracy by up to 32%. The performance of EFITNN demonstrates remarkable consistency with the offline EFIT, achieving average

R
2

=

0.941, 0.997 and 0.959 for eight plasmas parameters, Ψ

rz
and

J

P

, respectively. The model’s robust generalization capabilities are particularly evident in its successful predictions of quasi-snowflake (QSF) divertor configurations and its adept handling of data from shot numbers or plasmas current intervals not previously encountered during training. Compared to numerical methods, EFITNN significantly enhances computational efficiency with average computation time ranging from 0.08 ms to 0.45 ms, indicating its potential utility in real-time isoflux control and plasmas profile management.
Substantial reduction in population exposure to sea level changes along the Chinese mainland coast through emission mitigation
Authors: Jin Hu , Yuan Jiacan , Kulp Scott , Wang Hui , Li Dawei , Wang Guihua 
Published: September 2024

Abstract
Rising sea level increases the exposure to flooding and related damage in coastal areas with high population density and substantial economic activity. As global temperatures continue to rise due to climate change, sea levels have been consistently increasing and are projected to continue this upward trend. This study assesses the future exposure at provincial and city levels populations coastal mainland China coast to local sea level changes under five greenhouse gas (GHG) emission scenarios from IPCC-AR6, as well as two low-confidence scenarios accounting for the potential impact of uncertain ice sheet processes with low- and high-GHG emissions. We incorporate spatial heterogeneity into regional sea level projections and population projections from 2020 to 2100, extreme sea levels (ESLs) of 10-, 50-, and 100 year return periods (RP), and local coastal protection standards. Our findings indicate that the inundated areas expand continuously within the century with heightened exposure under higher emission scenarios. Although the coastal population is projected to decline, the fraction of the coastal population exposed to flooding increases across all scenarios, with accelerated growth under higher GHG emissions and higher ESLs. Zhejiang and Jiangsu emerge as the provinces most exposed to sea-level rise, whereas Taizhou, Nantong, Wuxi, Panjin, and Huzhou are identified as the top five cities with the highest population exposure to local sea level rise (SLR). Transitioning towards a sustainable scenario (i.e. SSP1-2.6) rather than a fossil fuel-intensive one (i.e. SSP5-8.5) can reduce the local SLR and substantially mitigate these exposures. Compared to the median projections under SSP5-8.5, aligning GHG emissions with SSP1-2.6 could reduce population exposure substantially in all coastal provinces, especially in Jiangsu, where population exposure to 100 year RP coastal floods would be reduced by ∼1.6 M in 2050 and by ∼5.4 M in 2100.