bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental studies of H2/Ar plasma in a cylindrical inductive discharge with an expansion region
Authors: Li 李 Shi-Bo 世博 , Xing 邢 Si-Yu 思雨 , Gao 高 Fei 飞 , Wang 王 You-Nian 友年 
Published: July 2024

Abstract
The electrical parameters of H2/Ar plasma in a cylindrical inductive discharge with an expansion region are investigated by a Langmuir probe, where Ar fractions range from 0% to 100%. The influence of gas composition and pressure on electron density, the effective electron temperature and the electron energy probability functions (EEPFs) at different spatial positions are present. In driver region, with the introduction of a small amount of Ar at 0.3 Pa, there is a rapid increase in electron density accompanied by a decrease in the effective electron temperature. Additionally, the shape of the EEPF transitions from a three-temperature distribution to a bi-Maxwellian distribution due to an increase in electron–electron collision. However, this phenomenon resulting from the changes in gas composition vanishes at 5 Pa due to the prior depletion of energetic electrons caused by the increase in pressure during hydrogen discharge. The EEPFs for the total energy in expansion region is coincident to these in the driver region at 0.3 Pa, as do the patterns of electron density variation between these two regions for differing Ar fractions. At 5 Pa, as the discharge transitions from H2 to Ar, the EEPFs evolved from a bi-Maxwellian distribution with pronounced low energy electrons to a Maxwellian distribution in expansion region. This evolve may be attributed to a reduction in molecular vibrational excitation reactions of electrons during transport and the transition from localized electron dynamics in hydrogen discharge to non-localized electron dynamics in argon discharge. In order to validate the experimental results, we use the COMSOL simulation software to calculate electrical parameters under the same conditions. The evolution and spatial distribution of the electrical parameters of the simulation results agree well with the trend of the experimental results.
Study of leakage current degradation based on stacking faults expansion in irradiated SiC junction barrier Schottky diodes
Authors: Luo 罗 Maojiu 茂久 , Zhang 张 Yourun 有润 , Wang 王 Yucheng 煜丞 , Chen 陈 Hang 航 , Zhou 周 Rong 嵘 , Wang 王 Zhi 智 , Lu 陆 Chao 超 , Zhang 张 Bo 波 
Published: July 2024

Abstract
A comprehensive investigation was conducted to explore the degradation mechanism of leakage current in SiC junction barrier Schottky (JBS) diodes under heavy ion irradiation. We propose and verify that the generation of stacking faults (SFs) induced by the recombination of massive electron--hole pairs during irradiation is the cause of reverse leakage current degradation based on experiments results. The irradiation experiment was carried out based on Ta ions with high linear energy transfer (LET) of 90.5 MeV/(mg/cm2). It is observed that the leakage current of the diode undergoes the permanent increase during irradiation when biased at 20% of the rated reverse voltage. Micro-PL spectroscopy and PL micro-imaging were utilized to detect the presence of SFs in the irradiated SiC JBS diodes. We combined the degraded performance of irradiated samples with SFs introduced by heavy ion irradiation. Finally, three-dimensional (3D) TCAD simulation was employed to evaluate the excessive electron–hole pairs (EHPs) concentration excited by heavy ion irradiation. It was observed that the excessive hole concentration under irradiation exceeded significantly the threshold hole concentration necessary for the expansion of SFs in the substrate. The proposed mechanism suggests that the process and material characteristics of the silicon carbide should be considered in order to reinforcing against the single event effect of SiC power devices.
Image encryption algorithm based on multiple chaotic systems and improved Joseph block scrambling
Authors: Mou 牟 Dingkang 定康 , Dong 董 Yumin 玉民 
Published: July 2024

Abstract
With the rapid development of digital information technology, images are increasingly used in various fields. To ensure the security of image data, prevent unauthorized tampering and leakage, maintain personal privacy, and protect intellectual property rights, this study proposes an innovative color image encryption algorithm. Initially, the Mersenne Twister algorithm is utilized to generate high-quality pseudo-random numbers, establishing a robust basis for subsequent operations. Subsequently, two distinct chaotic systems, the autonomous non-Hamiltonian chaotic system and the tent-logistic-cosine chaotic mapping, are employed to produce chaotic random sequences. These chaotic sequences are used to control the encoding and decoding process of the DNA, effectively scrambling the image pixels. Furthermore, the complexity of the encryption process is enhanced through improved Joseph block scrambling. Thorough experimental verification, research, and analysis, the average value of the information entropy test data reaches as high as 7.999. Additionally, the average value of the number of pixels change rate (NPCR) test data is 99.6101%, which closely approaches the ideal value of 99.6094%. This algorithm not only guarantees image quality but also substantially raises the difficulty of decryption.
Dynamics of fundamental and double-pole breathers and solitons for a nonlinear Schrödinger equation with sextic operator under non-zero boundary conditions
Authors: Zhang 张 Luyao 路瑶 , Xie 解 Xiyang 西阳 
Published: July 2024

Abstract
We study the dynamics of fundamental and double-pole breathers and solitons for the focusing and defocusing nonlinear Schrödinger equation with the sextic operator under non-zero boundary conditions. Our analysis mainly focuses on the dynamical properties of simple- and double-pole solutions. Firstly, through verification, we find that solutions under non-zero boundary conditions can be transformed into solutions under zero boundary conditions, whether in simple-pole or double-pole cases. For the focusing case, in the investigation of simple-pole solutions, temporal periodic breather and the spatial-temporal periodic breather are obtained by modulating parameters. Additionally, in the case of multi-pole solitons, we analyze parallel-state solitons, bound-state solitons, and intersecting solitons, providing a brief analysis of their interactions. In the double-pole case, we observe that the two solitons undergo two interactions, resulting in a distinctive “triangle” crest. Furthermore, for the defocusing case, we briefly consider two situations of simple-pole solutions, obtaining one and two dark solitons.
A proposal to change the leap-second adjustments to coordinated universal time
Authors: Levine Judah 
Published: July 2024

Abstract
The definition of Coordinated Universal Time (UTC) in 1972 balanced the needs of the time and frequency community for a universal time scale that was traceable to the definition of frequency in the SI system of units with the needs of the astronomical community for a time scale that was closely linked to UT1, a time scale related to the rotation of Earth. The balance between these two considerations has changed very significantly since 1972, and there is widespread agreement that the method of relating UTC to UT1 should be changed by increasing the magnitude of the maximum tolerance between the two scales to more than the current limit of 0.9 s. We propose to realize this decision by means of an algorithmic adjustment process based on the variation in the length of the day over the previous centuries. We use these historical data to extrapolate the length of the day for a century into the future, and to compute a periodic rate adjustment to UTC based on this extrapolation. The adjustment process will not use time steps. The magnitude of the periodic rate adjustment will be re-considered every century, but the basic adjustment algorithm will not change. We suggest a maximum tolerance between UT1 and UTC that is large enough to absorb the irregular and unpredictable variations in the length of the day with respect to the long-term average increase in this value but plays no role in determining the parameters of the adjustment process that is proposed. We also propose that the adjustment be implemented at 12 UTC on 1 January or on another date that is close to a universal holiday in all time zones.
Scaffold design considerations for peripheral nerve regeneration
Authors: Yu Le , Bennett Carly Jane , Lin Chung-Hsun , Yan Su , Yang Jian 
Published: July 2024

Abstract
Peripheral nerve injury (PNI) represents a serious clinical and public health problem due to its high incurrence and poor spontaneous recovery. Compared to autograft, which is still the best current practice for long-gap peripheral nerve defects in clinics, the use of polymer-based biodegradable nerve guidance conduits (NGCs) has been gaining momentum as an alternative to guide the repair of severe PNI without the need of secondary surgery and donor nerve tissue. However, simple hollow cylindrical tubes can barely outperform autograft in terms of the regenerative efficiency especially in critical sized PNI. With the rapid development of tissue engineering technology and materials science, various functionalized NGCs have emerged to enhance nerve regeneration over the past decades. From the aspect of scaffold design considerations, with a specific focus on biodegradable polymers, this review aims to summarize the recent advances in NGCs by addressing the onerous demands of biomaterial selections, structural designs, and manufacturing techniques that contributes to the biocompatibility, degradation rate, mechanical properties, drug encapsulation and release efficiency, immunomodulation, angiogenesis, and the overall nerve regeneration potential of NGCs. In addition, several commercially available NGCs along with their regulation pathways and clinical applications are compared and discussed. Lastly, we discuss the current challenges and future directions attempting to provide inspiration for the future design of ideal NGCs that can completely cure long-gap peripheral nerve defects.
Automated object detection for muon tomography data analysis
Authors: Georgadze Anzori Sh. 
Published: July 2024

Abstract
In recent years, there have been ongoing efforts to improve screening technologies to improve security and prevent terrorist threats. The most widely used technologies for scanning shipping containers are gamma and X-ray radiography, which can be harmful to operators and the environment. Muon tomography screening systems are considered as a potential tool to enhance border security and prevent terrorist threats or smuggling, especially in the context of shipping container inspections. Muon tomography uses naturally occurring cosmic ray muons to create detailed images of the inside of objects, such as shipping containers, without the need for physical intervention. Various realistic smuggling scenarios were simulated using the GEANT4 toolkit. The implemented filtering algorithms successfully reduce background noise from the surrounding cargo, enabling the detection of concealed threats and contraband. With the tools provided by the ROOT data analysis package, prohibited items can be automatically detected and localized in a cargo container.
Propulsive performance of a heaving and pitching foil with large amplitudes in unsteady ground effect
Authors: Zhang Jian-Tao , Nakamura Takashi 
Published: July 2024

Abstract
To reveal the effect of ground on the force behavior, propulsion performance, and vortex dynamics of a flapping foil, we numerically study a flapping foil actuated by combined heaving and pitching motions with large amplitudes near a solid ground surface. The instantaneous forces in both streamwise and cross-stream directions undergo a sudden drop during upstroke in close ground effect. The time-averaged thrust is enhanced by the ground but varies non-monotonically with ground distance at high foil oscillating frequencies. Three force regimes are identified in lift production, giving rise to two equilibrium altitudes of zero lift, one stable and another unstable. Moreover, we propose a simple scaling law model by a path-length-based Strouhal number and ground effect for thrust and power performance of a large-amplitude flapping foil. The results of the model are consistent with numerical results and previous experimental studies. The vortex dynamics in the wake structure are largely affected by ground proximity; in particular, the formed vortex pairs and their orientations are sensitive to their initial relative positions. Different sources and mechanisms of satellite vortex formation are then discussed. The ground exerts little effect on the phase angles that optimize the propulsive efficiency. This study is expected to provide new insights into the development and maneuvering of flapping foil-based propulsive systems.
Effect of nickel and selenium co-doping on molybdenum disulfide structure and its electrochemical activity in polysulfide electrolyte
Authors: Batu Kasaye Bayisa , Shura Megersa Wodajo , Dibaba Solomon Tiruneh 
Published: July 2024

Abstract
The development of a low-cost, and highly effective platinum (Pt)-free counter electrode (CE) that is highly stable towards polysulfide electrolyte presents a substantial challenge. Trigonal Molybdenum disulfide (1T-MoS2) has shown good chemical stability toward polysulfide electrolytes. In this study, 1T-MoS2 was prepared by co-doping with nickel (Ni) and selenium (Se) into MoS2 through hydrothermal method and utilizing its reduction activity toward polysulfide electrolyte. According to electrochemical impedance spectroscopy (EIS) analysis, Ni-Se-MoS2 has a low charge transfer resistance and electron recombination lifetime. In addition, cyclic voltmeter (CV) analysis reveals a high absolute area indicating a high level of electrocatalytic activity for polysulfide reduction at the electrolyte/counter electrode (CE) interface. The XRD analysis shows that the phase shifting of 2H MoS2 to 1 T MoS2 and the intensity of the co-doped sample is lower than that of others. SEM analysis reveals a microsphere-flower-like morphology that increases specific surface area.
Numerical simulation and experimental investigation on friction stir welding of AZ31 magnesium alloy
Authors: Yan Zehua , Liu Xinna , Yang Sheng , Zhang Wei 
Published: July 2024

Abstract
Integrated numerical simulations and experimental investigations were employed to scrutinize the thermal, mechanical, and microstructural transformations of the AZ31 magnesium alloy during the friction stir welding (FSW) process. Especially, the primary focus was on the influence of process parameters such as rotational speed and welding speed on the temperature distribution, grain refinement, and mechanical properties of welded joints in alloys. By employing Deform-3D coupled with the integration of constitutive equations and dynamic recrystallization (DRX) models, the FSW process was investigated. The investigation revealed a significant increase in temperature when the tool’s shoulder made contact with the weld, resulting in the substantial accumulation of heat during FSW. Distinctions became apparent between the advancing side (AS) and the receding side (RS), with the AS exhibiting slightly elevated levels of temperature, equivalent stress, strain, and grain size. Specifically, adjustments in the rotational speed of the stirring tool and a reduction in welding speed resulted in larger grain sizes within the alloy. For example, when the rotational speed was set at 1200 rpm and the travel rate was 200 mm min−1, the initial grain size of the weld experienced a substantial decrease from 57.8 μm to 8.2 μm. Subsequent experimental verification, considering grain size and microhardness, was carried out to optimize FSW parameters for achieving the desired material properties. The accuracy of simulation results was validated through a meticulous comparison with experimental findings, underscoring the potential of numerical simulation in comprehending and predicting FSW processes.
Simulation of different structured gate-all-around FETs for 2 nm node
Authors: Totorica Nathan , Hu Wei , Li Feng 
Published: July 2024

Abstract
This paper compares different types of Gate All Around (GAA) FET structures using TCAD simulation, including Lateral Nanosheet, Lateral Nanowire, Vertical Nanosheet, and Vertical Nanowire. The increase in electrostatic control and reduced short channel effects are key benefits to adopting GAAFET structures to meet scaling requirements for next generation process nodes. To understand channel geometry impacts on performance, the channel effective width (Weff) is swept around the projected dimensions, including ratio of height and width parameters. The performance is evaluated using the key device metrics such as on-state current (Ion), off-state current (Ioff), and threshold voltage (Vt) for transfer characteristics, and drain-induced barrier lowering (DIBL), subthreshold slope (SS), and gate induced drain leakage (GIDL) for short-channel effects. It is observed that thinner channel geometries, as often seen implemented in Nanosheet structures, have major benefits across SCE and Ioff metrics compared to more symmetrically square shaped channels. Additionally, stacking channels as a means to increase Weff appears to be an attractive option for increasing performance without significant increase in SCEs observed. For bulk technology the ratio between height and width of a Nanosheet structure can be optimized to reduce parasitic channel influence, so that optimal Ion/Ioff ratio is achieved.
Negative order sobolev cubatures: preconditioners of partial differential equation learning tasks circumventing numerical stiffness
Authors: Suarez Cardona Juan-Esteban , Hofmann Phil-Alexander , Hecht Michael 
Published: July 2024

Abstract
We present a variational approach aimed at enhancing the training of physics-informed neural networks (PINNs) and more general surrogate models for learning partial differential equations (PDE). In particular, we extend our formerly introduced notion of Sobolev cubatures to negative orders, enabling the approximation of negative order Sobolev norms. We mathematically prove the effect of negative order Sobolev cubatures in improving the condition number of discrete PDE learning problems, providing balancing scalars that mitigate numerical stiffness issues caused by loss imbalances. Additionally, we consider polynomial surrogate models (PSMs), which maintain the flexibility of PINN formulations while preserving the convexity structure of the PDE operators. The combination of negative order Sobolev cubatures and PSMs delivers well-conditioned discrete optimization problems, solvable via an exponentially fast convergent gradient descent for λ-convex losses. Our theoretical contributions are supported by numerical experiments, addressing linear and non-linear, forward and inverse PDE problems. These experiments show that the Sobolev cubature-based PSMs emerge as the superior state-of-the-art PINN technique.
Improving nutrition science begins with asking better questions
Authors: Stern Dalia , Ibsen Daniel B , MacDonald Conor James , Chiu Yu-Han , Lajous Martin , Tobias Deirdre K 
Published: July 2024

Abstract
A priority of nutrition science is to identify dietary determinants of health and disease to inform effective public health policies, guidelines, and clinical interventions. Yet, conflicting findings in synthesizing evidence from randomized trials and observational studies have contributed to confusion and uncertainty. Often, heterogeneity can be explained by the fact that seemingly similar bodies of evidence are asking very different questions. Improving the alignment within and between research domains begins with investigators clearly defining their diet and disease questions; however, nutritional exposures are complex and often require a greater degree of specificity. First, dietary data are compositional, meaning a change in a food may imply a compensatory change of other foods. Second, dietary data are multidimensional; that is, the primary components (ie, foods) comprise subcomponents (eg, nutrients), and subcomponents can be present in multiple primary components. Third, because diet is a lifelong exposure, the composition of a study population’s background diet has implications for the interpretation of the exposure and the transportability of effect estimates. Collectively clarifying these key aspects of inherently complex dietary exposures when conducting research will facilitate appropriate evidence synthesis, improve certainty of evidence, and improve the ability of these efforts to inform policy and decision-making.
Effects of moderate/vigorous activity on 3-year body composition changes in postmenopausal women: a target trial emulation
Authors: Li Jiarui , Bea Jennifer W , LaMonte Michael , Jiang Luohua , Reding Kerryn , Garcia Lorena , Manson Jo Ann E , Follis Shawna , Odegaard Andrew O 
Published: July 2024

Abstract
Postmenopausal women experience significant changes in body composition, particularly abdominal adipose tissue (AAT) deposition patterns, which influence cardiometabolic risk. Physical activity has demonstrable effects on body composition and overall health; however, there is little evidence for how physical activity influences AAT patterns and body composition in postmenopausal women. We emulated a target trial of physical activity interventions, including the 2018 Physical Activity Guidelines for Americans recommendations (≥150 minutes/week), on 3-year changes in AAT and body composition. We analyzed data from 4451 postmenopausal women aged 50-79 years in the Women’s Health Initiative (WHI) with repeated whole body Dual X-Ray Absorptiometry (DXA) scans with derived abdominal visceral (VAT) and subcutaneous adipose tissue (SAT). The mean AAT and body composition measures were estimated with the parametric-g formula. Over 3 years, interventions of increasing minutes of moderate activity would result in dose-dependent reductions in AAT, overall body fat and increases in lean soft tissue, with the greatest estimated benefit at the 2018 physical activity guideline recommendations. Compared to no intervention, if all participants had adhered to ≥150 mins/week of moderate physical activity, they would have 16.8 cm2 lower VAT (95% CI: −23.1, −10.4), 26.8 cm2 lower SAT (95% CI: −36.3, −17.3), 1.3% lower total body fat (95% CI: −1.8, −0.7), 1.2% higher total lean soft tissue (95% CI: 0.7-1.8), and 2.6 kg lower bodyweight (95% CI, −3.6, −1.5). We saw similar patterns in vigorous-intensity activity interventions. These results suggest that postmenopausal women who adhere to physical activity guideline recommendations would experience beneficial body composition changes over 3 years.