bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiments on kinematic characteristics and energy dissipation in rockfall movement on a slope
Authors: Peng Jia , Chen Dong , Hassan Marwan A. , Maniatis Georgios , Wang Lu , Nie Ruihua
Published: October 2024

This paper presents an experimental methodology for tracking trajectories of rockfall-saltation and extracting kinematic parameters from collisions between rockfalls and a slope surface. We conducted a series of experiments, each featuring different initial impact angles. Rockfall trajectories and their three-dimensional angular velocities were measured by a high-speed camera and built-in Inertial Measurement Unit (IMU), respectively. Our experiments demonstrate that rockfall dissipates its total energy as it progresses along the slope, and the dissipation rates are largely determined by the initial impact angle. Following the classification of rockfall-bed collisions into two modes—Mode-1: saltation dominant and Mode-2: rolling and sliding dominant, we examined the correlations between impact angles and the probability density functions of kinetic, linear, and rotational kinetic energy, as well as the coefficients of kinetic friction and restitution in both modes. Our findings highlight the crucial role of three-dimensional angular velocities in rockfall kinematics, displaying a notable divergence of up to 60% when compared with their two-dimensional counterparts. This is particularly evident in Mode-2, where the increase in rotational energy following collisions exceeds that of Mode-1 × 25%. The experimental investigation contributes to a deeper understanding of the fundamental physical processes inherent in successive rockfall-slope collisions, thereby benefitting predictive capabilities for rockfall disasters in mountainous regions.
High-performance InGaZnO power transistors: Effect of device structural parameters
Authors: Huo Wenxing , Zhang Yonghui , Fang Chenglong , Wu Ziyue , Yang Zhen , Mao Sui , Liu Xinyu , Qin Yang , Zhu Rui , Mei Zengxia , Huang Xian
Published: October 2024

In this work, the effect of offset channel length (Loffset) and the dielectric layer thickness (d) on the InSnO/InGaZnO (ITO/IGZO) dual-active-layer (DAL) high-voltage thin-film transistors (HV-TFTs) is systematically investigated. The characteristics of the DAL HV-TFTs resemble that of GaN high electron mobility transistors, wherein the breakdown voltages (VBD) reach saturation at a certain Loffset, and the on-resistance (Ron) linearly increases with Loffset. The linear fitting of Ron vs Loffset indicates that d has a multifaceted impact on the performance of HV-TFTs. In addition to its theoretical role in transistor models, d also influences the channel doping concentration and sidewall deposition issues in practical devices. The DAL HV-TFT with a 30-nm Al2O3 gate dielectric achieves a remarkable VBD of 450 V, the highest figure of merit of 118.2 kW/cm2, and a positive threshold voltage of 3.65 V. Both experiments and simulations indicate that the breakdown occurs within the semiconductor channel, paving the way for further improvement of the performance.
The MnAl-alloy nanoparticles incorporated PVDF-based piezoelectric nanogenerator as a self-powered real-time pedometer sensor
Authors: Das Tupan , Rout Sushree Nibedita , Dev Amar , Kar Manoranjan
Published: October 2024

This study introduces a flexible, sensitive, and cost-effective hybrid piezoelectric nanogenerator (PENG) by integrating MnAl-alloy nanoparticles into a poly (vinylidene fluoride) (PVDF) nanocomposite film. The MnAl-alloy nanoparticles serve as a nucleating agent for promoting the formation of the electroactive β-phase. It is observed that the electroactive β-phase, dielectric permittivity, saturation polarization, and output performance of the device improve with the incorporation of the MnAl-alloy nanoparticles up to 7.5 wt. % in the PVDF matrix. Hence, in this work, we report a MnAl-alloy-based optimized piezoelectric nanogenerator device using a free-standing nanofiber mat (7.5 wt. % MnAl-alloy) prepared by the electrospinning technique. The as-fabricated piezoelectric nanogenerator effectively channels charges generated by mechanical stress to the electrodes, resulting in an impressive output voltage of approximately 16 V and an output current of around 7.1 μA, yielding a power of 47 μW across 4.5 MΩ resistor. Furthermore, energy harvesting from human movements such as jogging, knee bending, and walking is demonstrated for practical application. A piezo potential of approximately 8 V generated during walking showcases the development of a self-powered pedometer. Furthermore, tapping the PENG charges a capacitor of 0.1 μF up to approximately 1 V, demonstrating the potential application for the power up of small portable electronic devices.
Josephson spin valve controlled by a superconducting trigger effect
Authors: Neilo Alexey , Bakurskiy Sergey , Klenov Nikolay , Soloviev Igor , Stolyarov Vasily , Kupriyanov Mikhail
Published: October 2024

The supercurrent in a Josephson SF1S1F2sIS spin valve (“S” is for superconductor, “F” is for ferromagnet, and “I” is for insulator) is studied theoretically. It is found that by rotating the magnetization of one of the ferromagnetic layers, a smooth switching of the system between two states with different critical currents is possible. The operating range of the device can be adjusted by varying the thickness of the intermediate s-layer. The proposed structure is a promising scalable control element for the use in superconducting electronics.
A route to an all direct laser written integrated FTS (SWIFTS) in the 3.39–4.1 μm range
Authors: Bonduelle Myriam , Martin Guillermo , Morand Alain , Vázquez de Aldana Javier R. , Heras Víctor Arroyo , Romero Carolina
Published: October 2024

This work aims to present the building blocks for an all direct laser written integrated spectrometer in the mid-infrared (3.39–4.1 μm range) based on the SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) principle. In a SWIFTS-Gabor configuration, the light from the source interferes with itself in the middle of a channel waveguide, creating a stationary wave. This interferogram is then sampled through scattering centers placed on top of the waveguide that radiate the light they extract onto a detector placed directly on the sample. Finally, the spectrum of the source is retrieved through a Fourier transform. To implement a SWIFTS, two main photonic functions are required: the waveguide and the scattering centers. In this work, both functions have been created using Direct Laser Writing (DLW), a versatile technique, allowing to easily access 3D configurations and to reduce fabrication time. DLW focuses a femtosecond laser onto a sample so as to locally change the crystal lattice, resulting in its structural modification. The waveguides presented here are surface half-circular cladding structures made through type II modifications in the sample, and the scattering centers are surface damage tracks (also referred to as grooves). These surface tracks are creating dielectric discontinuities in the evanescent part of the stationary wave, resulting in the light being radiated outside the waveguide. All of these are made in a z-cut lithium niobate substrate for future implementation of the electro-optic effect. We demonstrate that we have functional waveguides in the mid-IR and that our grooves are extracting the stationary wave as expected, showing promising results for future implementation of a complete mid-IR SWIFTS using DLW.
Bias-induced magnetic to nonmagnetic transition in polyacene junctions
Authors: Li J. T. , Zhang H. Q. , Ma H. , Li H. X. , Wang Y. , Wang C. , Zhang G. P. , Ren J. F. , Hu G. C.
Published: October 2024

By means of the first-principles method, the bias effect on the magnetism of polyacene (n-acene) connected to gold electrodes is investigated. A magnetic to nonmagnetic transition for the polyacene (n > 6) is observed when the bias exceeds a critical value. The mechanism is explored as the bias-induced variation of electronic localization, which leads to the exchange of dominant mechanism for molecular magnetism from Columbic interaction between electrons to electron hopping rate. A significant enhancement of the differential conductance and suppression of current spin polarization for the molecular device are also obtained accompanied by the transition of molecular magnetism. This work proposes a feasible way to manipulate the magnetism of polyacene via electric method and reveals the relation between molecular magnetism and its conductance.
Passivation mechanisms of oxygen-vacancy-induced hole traps by Mg acceptor atoms at GaN/SiO2 interface
Authors: Hattori Shuto , Oshiyama Atsushi , Shiraishi Kenji
Published: October 2024

Experiments in the past suggest that hole traps at GaN/SiO2 interfaces are reduced with heavily Mg-doped GaN epitaxial layers, but its physical origin is unclear. In this study, we use first-principles calculations to investigate interactions between substitutional Mg atoms at Ga sites (MgGa) and O vacancies (VO) in the nanometer-scale Ga-oxide (GaOx) interfacial layers, which are inevitably formed at GaN/SiO2 interfaces. We clarify the physical reason why Mg passivates hole traps. Our calculations show that MgGa and VO become stable by forming 2MgGa–VO complex in GaOx. In addition, while VO form deep hole traps in the bandgap of GaN, Mg attachment to VO makes the hole-trap level shift upward substantially and thus 2MgGa–VO induces no hole traps. These results indicate that hole traps originated from VO are passivated by the formation of a complex of MgGa atoms and VO.
Application of hydrophobic catalyst in formaldehyde–ethylene condensation reaction
Authors: Li Jianxiang , Zhang Qiang , Li Chunyi , Kang Hao , Wang Yuelin
Published: October 2024

Using hydrophobic aerogel (AGL) as the carrier, the catalyst supported p-toluene sulfonic acid (p-TSA) is synthesized, and the impact of the hydrophobicity of the catalyst on the formaldehyde–ethylene condensation reaction is investigated. Water contact angle, XRD, N2 adsorption/desorption, IR, and thermogravimetric analysis are used to characterize the catalyst. The outcomes demonstrate the ability of p-TSA to be loaded onto the carrier and the strong hydrophobicity of the catalyst when using AGL as the carrier. The elemental analysis results indicate that when AGL is employed as the carrier, the catalyst not only has more active sites than the SiO2-supported catalyst, but can also effectively limit the loss of active sites, reducing the loss rate from 25.82% to 15.03%. The findings demonstrate that 1,3-dioxane (1,3-DX) had a higher selectivity, rising from 16.2% to 33.3% when using AGL as the carrier. It is discovered that 1,3-propanediol (1,3-PDO) can be directly synthesized with a selectivity of up to 80.5% by employing acetic acid as a solvent in place of water.
Large eddy simulation of turbulent wake from dual-step cylinders
Authors: Theja Charan , Sathia Kishore Ram , Mahesh Somasani , Narasimhamurthy Vagesh D.
Published: October 2024

Numerical computations of the three-dimensional flow past dual-step cylinders using large eddy simulations are performed. The Reynolds number based on the diameter of the large cylinder, ReD, is fixed at 2000. The diameter ratio between the two cylinders is kept constant in all computations, i.e., D/d=2, where d is the diameter of the small cylinder. Investigations are carried out at different aspect ratios (ARs), defined as the ratio between the length of the large cylinder and its diameter L/D=0.2,0.5,1.0,1.5. Vortex dislocation phenomenon is observed in all the cases near the step discontinuity. The higher AR cases, L/D=1.0,1.5, exhibit similar trends with regard to wake dynamics, while they are quite different in the lower AR cases, L/D=0.2,0.5. Kelvin–Helmholtz instability is present in the wake of the dual-step cylinder with higher AR. Stable in-phase shedding and downwash characterize the wake of higher AR configurations, while oblique shedding (and flipping) is the key feature in the lower AR counterparts. Unique features are observed in the L/D=1.0 configuration that marks the transition between shedding modes.
Viscous/viscoelastic Rayleigh–Taylor instability accounting for the number of fingers in a droplet impacting a plane surface
Authors: Dai J. L. , Sun Y. B. , Wang C. , Zeng R. H.
Published: October 2024

In this study, we develop unified and analytical frameworks to examine the effect of viscosity, elasticity, and viscoelasticity on the Rayleigh–Taylor instability (RTI), which underlies finger formation during prompt splashing as a droplet impacts a flat metal surface. We complement our theoretical developments with experimental validations designed to match our theoretical predictions. A new dimensionless number, R=Re/We3/4, is introduced to characterize the evolution of the finger patterns. Three distinctive regimes are identified based on our analysis: when R≲1, the number of fingers scales with Re2/3; for 1≲R≲10, the finger count is influenced by both Re and We, a regime not extensively studied previously; and for R≳10, the count becomes insensitive to Re. We also discern a transient deceleration effect, represented by g=16V02/D, which prompts perturbation development due to RTI. It is noted that the constant 16 is dependent on fluid and surface physical properties. Though our theoretical predictions closely align with experimental observations, it is noteworthy that in experimental settings, g exhibits significant temporal variability. Further, our study extends to include viscoelastic effects, facilitating comparisons with recent advancements in managing finger formation in splashing scenarios. Additional experiments targeting medium R values further corroborate our theoretical model. This comprehensive analysis not only reaffirms but also enhances the understanding of splashing dynamics by integrating complex material behaviors and characteristics, thus offering a substantive benchmark for future research in the field.
Research on supersonic film cooling of hypersonic optical window under different nozzle pressure ratios
Authors: Sun Xiaobin , Ding Haolin , Yi Shihe , Liu Mingxing , Huo Jiabo
Published: October 2024

When optical imaging-guided aircraft flies at hypersonic speeds in the atmosphere, the optical window withstands severe aerodynamic heating. Conducting the thin film resistance thermometer measurements in a hypersonic gun wind tunnel with a Mach number of 7.1 and total temperature of 670 K, the study investigates the effect of nozzle pressure ratio (NPR = film exit static pressure/nearby mainstream static pressure) on supersonic (Mach 2.43) film cooling for the hypersonic optical window. By combining the flow information near the window obtained using the three-dimensional compressible Reynolds-averaged Navier–Stokes method, the study reveals the mechanism of the effect of NPR on film cooling. The results indicate that increasing NPR can enhance the momentum of the unit volume film and improve the film's ability to resist mainstream mixing. Moreover, the film with a large NPR can better maintain its own momentum, leading to an increase in the film effective cooling length and film cooling effectiveness. The film effective cooling length corresponding to the unit mass flow rate of the cooling gas increases with the increase in NPR. It verifies the nonlinear relationship between the film cooling performance and the coolant mass flow rate, indicating the additional benefits of increasing NPR on the film cooling performance. Through research, it is found that increasing NPR can increase the film thickness, thereby enhancing its ability to isolate the mainstream. Moreover, as NPR increases, the cooling film expands, objectively leading to the widening of the film flow channel, allowing the Mach number of the supersonic film to increase continually. This further reduces the static temperature of the film in the flow field, thereby enhancing its cooling capability for the mainstream.
A 90SrHfO3-based betavoltaic/beta-photovoltaic dual-effect integrated nuclear battery
Authors: Cui Qiming , Lu Jingbin , Zhang Yu , Yuan Xinxu , Li Chengqian , Zhao Yang , Zheng Renzhou , Li Xiaoyi , Liu Yuxin , Liu Xinrui
Published: October 2024

In this paper, the secondary conversion idea is used to reduce the self-absorption effect of the radioactive source by combining the radioactive source with the scintillation material, so as to enhance the energy conversion efficiency of the battery. A theoretical model of a dual-effect integrated nuclear battery based on 90SrHfO3 doped with Ce is proposed. The emission photon and electron spectra of the β-luminescent integrated radioactive source 90SrHfO3 have been calculated by GEANT4. The average outgoing electron energy of SrHfO3 was calculated, and the thickness of the energy reducing material was determined. The effect of structural parameters of GaAs materials on the dual-effect integrated nuclear battery was analyzed to obtain the optimal output performance according to theoretical calculation. From the perspective of conversion efficiency, the activity density and thickness of 90SrHfO3 are determined to be 1.6 Ci/cm2 and 53.6 μm. At this time, the thickness of SrHfO3 is 1.28 mm. The total maximum output power density of the optimized dual-effect integrated nuclear battery is 9.31 μ W/cm2, and the energy conversion efficiency is 0.18 %. At this point, the doping concentrations of GaAs are Na = 1.26 × 1017 cm−3 and Nd = 6.31 × 1018 cm−3, and xj is 0.05 μm. Compared with nonintegrated batteries, the output performance is significantly improved.
Forecasting two-dimensional channel flow using machine learning
Authors: Aravanis Theofanis , Chrimatopoulos Grigorios , Xenos Michalis , Tzirtzilakis Efstratios E.
Published: October 2024

Over the past decade, the integration of artificial neural networks (ANNs) has garnered significant interest, capitalizing on their ability to discern intricate patterns within data. Focused on enhancing computational efficiency, this article explores the application of ANNs in forecasting fluid-dynamics simulations, particularly for the benchmark problem of fluid flow in a two-dimensional (2D) channel. Leveraging a multilayer perceptron trained on finite volume method numerical data, for both interpolation and extrapolation estimations and various grid resolutions, our findings demonstrate the ANN's prowess as a swift and accurate surrogate for traditional numerical methods. Overall, the results of this work mark a pioneering step toward leveraging machine learning for modeling complex relationships in fluids phenomena, promising transformative advancements in computational fluid dynamics.
Melt flow analysis in rotational nozzle fused filament fabrication process
Authors: Liu Zijie , Estela García John E. , Osswald Tim A. , Román Allen J.
Published: October 2024

Fused filament fabrication (FFF) is a widely used processing method; however, heat transfer limitations within a conventional nozzle result in relatively low flow rates, leading to lengthy production times, compared to traditional processing methods, ultimately restricting its industrial application. Recently, a novel rotational nozzle FFF three-dimensional (3 D) printer has been patented and developed to enhance processing efficiency. Despite this achievement, the fundamental mechanisms behind this novel process remain unclear. In this study, both analytical analysis and numerical simulations were conducted based on a force-controlled scaled-down experimental setup. This setup, designed according to the pressure-induced melt removal theory, provided melt throughput data under varying heater temperatures, extrusion forces, and rotational speeds. Agreement between the modeling and experimental results confirms the generalizability of the models. Modeling predictions of temperature and velocity distributions indicate that viscous dissipation affects the average temperature and filament velocity. To simulate the real-world working conditions of FFF 3 D printing, a velocity-controlled simulation was introduced. It was observed that the average melt film thickness increases with nozzle rotational speed due to viscous dissipation. Additionally, the extrusion force required for the same printing speed decreases with increasing nozzle rotational speed, primarily due to the higher shear rate reducing melt viscosity.
Comparative S/TEM study of superconducting Ta quantum resonators by wet and dry etching types
Authors: Mun Junsik , Zhou Chenyu , Kisslinger Kim , Liu Mingzhao , Zhu Yimei
Published: October 2024

Superconducting resonators play a pivotal role in various quantum technology applications, such as quantum computing and high-frequency communication systems. The performance of these resonators is closely tied to the properties of the superconducting films used in their fabrication. In this study, we investigated the impact of wet and dry etching on tantalum (Ta) films leveraging advanced scanning transmission electron microscopy-based characterization methods and examined the morphological, chemical, and strain changes caused by the etching processes. Consequently, we report the significant differences between the two etching methods, with dry etching resulting in straight slanted sidewalls and a thinner oxidized layer, while wet etching produced curved sidewalls and undercuts. Both methods led to the formation of a residual Ta wedge at the lower part of the sidewall, causing lattice deformation, which could adversely influence the homogeneous operations of superconducting devices. These insights enhance our understanding of how etching influences superconducting films, offering valuable guidance for optimizing resonators and related devices. Our findings mark a significant stride in advancing quantum technologies and high-frequency communication by enhancing our practical understanding of superconducting material fabrication.
Flowfield reconstruction in a supersonic isolator based on proper orthogonal decomposition and sensor compression coupling under variable Mach numbers
Authors: Wang Kai , Kong Chen , Wang Lijun , Chang Juntao
Published: October 2024

The supersonic inflow passes through the shock train in the isolator of the scramjet to complete deceleration and pressurization, followed by combustion and energy release, providing strong thrust. When the back pressure generated by combustion is disturbed forward, the location of shock train leading edge (STLE) will also change accordingly. Once it moves to the entrance of the isolator, it will cause unstart. Accurately detecting STLE in the isolator of a scramjet is crucial for controlling the shock train and preventing the inlet from unstart. Therefore, based on the sparse reconstruction of compressive sensing and sensor compression coupling, a supersonic flowfield reconstruction model (POD-STLE) based on proper orthogonal decomposition (POD) was constructed to reconstruct the supersonic flowfield and detect the location of STLE in the supersonic isolator. The experiments were conducted on the shock oscillation under variable Mach numbers and back pressures, to construct the experimental dataset. Combining supersonic flowfield reconstruction and matrix decomposition, different sensor layouts were constructed, which can ensure accuracy and stability while saving sensor resources. The POD-STLE was applied to the flowfield reconstruction of the supersonic isolator, and the location of STLE was detected under variable and constant conditions, ultimately achieving the expected reconstruction effect and detection accuracy. This study provides a new research method for detecting the location of STLE in the supersonic isolator of a scramjet and provides technical for exploring supersonic flowfield.
Assessment of the similarity-transformed equation of motion (STEOM) for open-shell organic and transition metal molecules
Authors: Casanova-Páez Marcos , Neese Frank
Published: October 2024

This study benchmarks the newly re-implemented single-reference excited-state methods, IP-EOM-CCSD, EA-EOM-CCSD, and STEOM-CCSD, in ORCA6.0, with a focus on open-shell systems. We compare STEOM against EOM-CCSD, CC3, and CCSDT across a range of systems, including small organic radicals, hydrated transition metal (TM) ions, and TM diatomic systems with both closed and open-shell configurations. For organic radicals, STEOM and EOM-CCSD show comparable performance, aligning closely with CC3 and CCSDT results. In the case of hydrated TM ions, IP-EOM closely matches DLPNO-CCSD results, while deviations from DLPNO-CCSD(T) are consistent. For open-shell TM systems, IP-EOM exhibits a blueshift relative to both the DLPNO-CCSD methods, while EA-EOM-CCSD shows better agreement. When comparing STEOM and CC3 to CCSDT, STEOM shows slightly larger deviations in closed-shell systems but shows excellent agreement in open-shell systems. Computational efficiency is also assessed, revealing a significant speedup in ORCA 6.0 compared to ORCA 5.0, with optimizations improving computation times. This study provides valuable insights into the performance and efficiency of STEOM in various chemical environments, highlighting its strengths and limitations.
Robust edge photogalvanic effect in thin-film WTe2
Authors: Zhang Yang , Wang Jia-Le , Xue Xiao-Lan , Nie Yue , Shi Dan-Ni , Zhang Shao-Bo , Chen Ling-Xiu , Shi Li-Wei
Published: October 2024

The photogalvanic effect (PGE) in Weyl semimetals, such as WTe2 and MoTe2, has been widely observed and is considered a promising phenomenon for advancing Weyl semimetal-based optoelectronic devices. However, as device dimensions continue to shrink, edge effects on photocurrent generation and modulation become increasingly significant and cannot be overlooked. Herein, we have discovered a locally enhanced edge linear photogalvanic effect at the edge of WTe2 thin-film devices using a home-built polarization-modulated scanning photocurrent system, which arises from symmetry breaking. Furthermore, the magnitude and direction of this edge photocurrent are modulated by the polarization direction of the incident light. This research provides valuable insights for the development of polarization-sensitive photodetectors based on layered type-II Weyl semimetals.
Data-driven guided physics-informed segmented neural network for liquid–vapor flash calculation
Authors: Hua Jinyu , Du Xin , Yang Feng , Lu Detang
Published: October 2024

Liquid–vapor phase equilibrium is ubiquitous in industrial and engineering field, which involves the flash calculation. The conventional flash calculation is solved with the numerical simulator, accompanying with large computational efforts. In this paper, we propose a data-driven guided physics-informed segmented neural network (DDG-PISNN) for the liquid–vapor pressure–temperature flash calculation. The training of DDG-PISNN is divided into two stages. First, a classifier for determining the stability of the system and a guiding network are built using data-driven methods. Subsequently, various control equations are employed to construct loss functions based on the results of classifier. In this way, DDG-PISNN fully leverages the advantages of data-driven approaches and physical equations. The accuracy and robustness of DDG-PISNN are calibrated by experiments under different conditions, and the performance is compared with that of DDG-PINN. In addition, a surrogate model for flash calculation is constructed based on DDG-PISNN. The accuracy of the surrogate model is also validated against a numerical case, and the computational efficiency is more than 800 times. Then, the surrogate model is embedded into the reservoir simulation technique to perform the flash calculation and form a surrogate-based compositional model. The surrogate-based model is employed to simulate the process of CO2 displacing crude oil. The results are in good agreement with the results of numerical solution.
Voluntary assisted dying: impacts on health professionals
Authors: Lamba Geetanjali (Tanji) , LaBrooy Camille , Lewis Sophie , Olver Ian , Holmes Alexander , Stewart Cameron , Komesaroff Paul
Published: October 2024

Objective The introduction and implementation of voluntary assisted dying (VAD) legislation represents a major shift in Australian health policy. Given potential repercussions for health professionals, understanding how they are being affected by this legislation is important to guide future policy and legislative changes. This study aims to explore the perspectives and experiences of Australian health professionals on VAD and compare impacts on those working under different state legislation in Victoria and WA. Methods Data were collected using a cross-sectional survey design, targeting health professionals nationally, primarily doctors and nurses. The survey had closed and open-ended response options, was informed by previous publications and was piloted prior to further roll-out. Recruitment was via professional networks and social media. Quantitative data were descriptively analysed and qualitative data were coded using NVivo and thematically analysed. Results There was a final sample size of 223. Impacts on clinicians identified include inadequate remuneration, a need for ongoing support and the recognition of barriers to mandatory training. Conclusions Impacts on health practitioners, if not addressed, have future implications for workforce sustainability. Increasing numbers of trained VAD practitioners may enable distribution of clinical load and prevent burnout. VAD practitioners are not being appropriately remunerated, which could be addressed by introducing dedicated Medicare Benefits Schedule items for VAD. Attention should also be given to incentivising training, including continuing professional development accreditation and appropriate funding. Strategies to support staff could include debriefing, mentoring, peer support and psychological consultations.
Health benefits of US light-duty vehicle electrification: Roles of fleet dynamics, clean electricity, and policy timing
Authors: Schmitt Jean , Hatzopoulou Marianne , Abdul-Manan Amir F.N. , MacLean Heather L. , Posen I. Daniel
Published: October 2024

We present a dynamic perspective to quantify the air quality–related health impacts of the electrification of light-duty vehicles in the United States between 2022 and 2050. Using a fleet turnover model and future electricity generation mix scenarios, we compare ambitious vehicle electrification to fleet renewal relying on newer internal combustion engine vehicles, without electric vehicles. The model includes vehicle-level pollutant emission factors and a reduced complexity air quality and valuation model and covers direct (tailpipe, brake wear, and tire wear) and indirect (production of electricity and liquid fuels) emissions of NO
x
, SO
2
, PM
2.5
, NH
3
, and VOCs, with a breakdown at the county level to identify geographical disparities in the distribution of health impacts. Short-term health benefits are mostly generated by reductions in NO
x
emissions from newer gasoline vehicles, while fleet electrification generates further benefits in the long term. The electricity mix plays a crucial role in the success of electrification policies. With continued grid decarbonization, electrification would reduce harmful air quality–related health impacts cumulatively by 84 to 188 billion USD over the study period, compared with fleet renewal without electric vehicles. In contrast, artificially freezing the 2022 grid would make electrification responsible for 32 to 71 billion USD additional health disbenefits compared with fleet renewal. Finally, we show that while fleet electrification achieves most of its benefits over fleet renewal in the long term, delaying the implementation of such policies would sacrifice meaningful cumulative benefits.
Asymmetric winter warming reduces microbial carbon use efficiency and growth more than symmetric year-round warming in alpine soils
Authors: Li Ling , Xu Qicheng , Jiang Shengjing , Jing Xin , Shen Qirong , He Jin-Sheng , Yang Yunfeng , Ling Ning
Published: October 2024

Asymmetric seasonal warming trends are evident across terrestrial ecosystems, with winter temperatures rising more than summer ones. Yet, the impact of such asymmetric seasonal warming on soil microbial carbon metabolism and growth remains poorly understood. Using
18
O isotope labeling, we examined the effects of a decade-long experimental seasonal warming on microbial carbon use efficiency (CUE) and growth in alpine grassland ecosystems. Moreover, the quantitative stable isotope probing with
18
O-H
2
O was employed to evaluate taxon-specific bacterial growth in these ecosystems. Results show that symmetric year-round warming decreased microbial growth rate by 31% and CUE by 22%. Asymmetric winter warming resulted in a further decrease in microbial growth rate of 27% and microbial CUE of 59% compared to symmetric year-round warming. Long-term warming increased microbial carbon limitations, especially under asymmetric winter warming. Long-term warming suppressed the growth rates of most bacterial genera, with asymmetric winter warming having a stronger inhibition on the growth rates of specific genera (e.g.,
Gp10
,
Actinomarinicola
,
Bosea
,
Acidibacter
, and
Gemmata
) compared to symmetric year-round warming. Bacterial growth was phylogenetically conserved, but this conservation diminished under warming conditions, primarily due to shifts in bacterial physiological states rather than the number of bacterial species and community composition. Overall, long-term warming escalated microbial carbon limitations, decreased microbial growth and CUE, with asymmetric winter warming having a more pronounced effect. Understanding these impacts is crucial for predicting soil carbon cycling as global warming progresses.
Intensive leaf cooling promotes tree survival during a record heatwave
Authors: Posch Bradley C. , Bush Susan E. , Koepke Dan F. , Schuessler Alexandra , Anderegg Leander L.D. , Aparecido Luiza M.T. , Blonder Benjamin W. , Guo Jessica S. , Kerr Kelly L. , Moran Madeline E. , Cooper Hillary F. , Doughty Christopher E. , Gehring Catherine A. , Whitham Thomas G. , Allan Gerard J. , Hultine Kevin R.
Published: October 2024

Increasing heatwaves are threatening forest ecosystems globally. Leaf thermal regulation and tolerance are important for plant survival during heatwaves, though the interaction between these processes and water availability is unclear. Genotypes of the widely distributed foundation tree species
Populus fremontii
were studied in a controlled common garden during a record summer heatwave—where air temperature exceeded 48 °C. When water was not limiting, all genotypes cooled leaves 2 to 5 °C below air temperatures. Homeothermic cooling was disrupted for weeks following a 72-h reduction in soil water, resulting in leaf temperatures rising 3 °C above air temperature and 1.3 °C above leaf thresholds for physiological damage, despite the water stress having little effect on leaf water potentials. Tradeoffs between leaf thermal safety and hydraulic safety emerged but, regardless of water use strategy, all genotypes experienced significant leaf mortality following water stress. Genotypes from warmer climates showed greater leaf cooling and less leaf mortality after water stress in comparison with genotypes from cooler climates. These results illustrate how brief soil water limitation disrupts leaf thermal regulation and potentially compromises plant survival during extreme heatwaves, thus providing insight into future scenarios in which ecosystems will be challenged with extreme heat and unreliable soil water access.
Migrasomes: Biogenesis, physiological roles, and therapeutic potentials
Authors: Jiao Haifeng , Yu Li
Published: October 2024

Migrasomes, vesicular structures discovered in migrating cells, arise from the junctions or tips of retraction fibers, and gradually grow to microscale vesicles. Migrasomes have garnered attention for their role in intercellular communication and potential therapeutic implications. This review presents an overview of recent advances in migrasome biology, covering the mechanisms of migrasome biogenesis, essential physiological roles, and their association with various diseases, alongside potential therapeutic applications. Furthermore, we share our perspectives on potential future directions in the study of migrasomes and highlight the challenges that remain in this developing area of research.
How condensed are mitotic chromosomes?
Authors: Konishi Hide A. , Funabiki Hironori
Published: October 2024

Chromosomes undergo dramatic compaction during mitosis, but accurately measuring their volume has been challenging. Employing serial block face scanning electron microscopy, Cisneros-Soberanis et al. (https://doi.org/10.1083/jcb.202403165) report that mitotic chromosomes compact to a nucleosome concentration of ∼760 µM.
EURAMET.T-K9 regional key comparison ITS-90 SPRT calibration from the Ar TP to the Zn FP
Authors: Sparasci Fernando , Risegari Lara , Martin Catherine , Hermier Yves , Lopardo Giuseppina , Steur Petrus Paulus Maria , Pearce Jonathan , Bünger Lars , Rudtsch Steffen , Bruin-Barendregt Conny de , Panman Matthijs , Peruzzi Andrea , Hofstätter-Mohler Christina , Turzó-András Emese , Nedialkov Sasho , Spasova Snezhana , Petrusova Olgica , José Martín Hernandez Maria , Maldonado Dolores del Campo , García Izquierdo Carmen , Strnad Radek , Simic Slavica , Stepanovic Vladan , Nielsen Jan , Kokkini Evmorfia , Gaidamovičiūtė Lilijana , Galkauskas Linas , Mikalauskas Kęstutis , Kozicki Marek , Zvizdić Davor , Šestan Danijel , Mutapčić Nedzadeta , Stratulat Camelia , Neagu Marius Dumitru , Eusébio Liliana , Olsen Åge Andreas Falnes , Bergerud Reidun Anita , Opel Karsten , Kvernmo Gjermund , Högström Richard , Heinonen Martti , Bojkovski Jovan , Žužek Vincencij , MacLochlainn Dubhaltach , Holmsten Magnus , Senn Remo , Dobre Miruna , Pavlasek Peter , Kalemci Murat
Published: October 2024

Main text

This is a report to the Technical Committee for Thermometry of EURAMET (EURAMET TC-T) on the regional key comparison EURAMET.T-K9 of SPRT calibration on the International Temperature Scale of 1990 (ITS-90), from 83.8058 K (the Ar triple point) to 692.677 K (the Zn fixed point). The transfer standards used are long-stem SPRTs.

EURAMET.T-K9 is an RMO key comparison linked to the CIPM key comparison CCT-K9. The comparison is organized in five separate collapsed Stars, each one having a CCT-K9 participant as pilot, which provides the link to the KCRV of CCT-K9. Four to five participating laboratories are involved in each Star. The pilots of the five Stars are LNE-Cnam, PTB, INRiM, VSL, NPL. LNE-Cnam is also the coordinator of the comparison, in charge of the collection of the measurement reports from all participants and the preparation of the final report.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Impact of bias stress and endurance switching on electrical characteristics of polycrystalline ZnO-TFTs with Al2O3 gate dielectric
Authors: Rowlinson Ben D , Zeng Jiale , Patzig Christian , Ebert Martin , Chong Harold M H
Published: October 2024

This study experimentally investigates electrical characteristics and degradation phenomena in polycrystalline zinc oxide thin-film transistors (ZnO-TFTs). ZnO-TFTs with Al2O3 gate dielectric, Al-doped ZnO (AZO) source–drain contacts, and AZO gate electrode are fabricated using remote plasma-enhanced atomic layer deposition at a maximum process temperature of 190 °C. We employ positive bias stress (PBS), negative bias stress (NBS), and endurance cycling measurements to evaluate the ZnO-TFT performance and examine carrier dynamics at the channel-dielectric interface and at grain boundaries in the polycrystalline channel. DC transfer measurements yield a threshold voltage of −5.95 V, a field-effect mobility of 53.5 cm2/(V∙s), a subthreshold swing of 136 mV dec−1, and an on-/off-current ratio above 109. PBS and NBS measurements, analysed using stretched-exponential fitting, reveal the dynamics of carrier trapping and de-trapping between the channel layer and the gate insulator. Carrier de-trapping time is 88 s under NBS at −15 V, compared to 1856 s trapping time under PBS at +15 V. Endurance tests across 109 cycles assess switching characteristics and temporal changes in ZnO-TFTs, focusing on threshold voltage and field-effect mobility. The threshold voltage shift observed during endurance cycling is similar to that of NBS due to the contrast in carrier trapping/de-trapping time. A measured mobility hysteresis of 19% between the forward and reverse measurement directions suggests grain boundary effects mediated by the applied gate bias. These findings underscore the electrical resilience of polycrystalline ZnO-TFTs and the aptitude for 3D heterogeneous integration applications.
Layer-number and strain effects on the structural and electronic properties of PtSe2 material
Authors: Amairi Rania , Smiri Adlen , Jaziri Sihem
Published: October 2024

Bandgap engineering of low-dimensional materials forms a robust basis for advancements in optoelectronic technologies. Platinum diselenide (PtSe2) material exhibits a transition from semi-metal to semiconductor (SM-SC) when going from bulk to monolayer. In this work, density functional theory (DFT) with various van der Waals (vdW) corrections has been tested to study the effect of the layer-number on the structural and electronic properties of the PtSe2 material. The considered vdW corrections gave different results regarding the number of layers at which the SM-SC transition occurs. This variation is due to the different interlayer distances found for each correction, revealing the sensitivity of the bandgap to this distance in addition to the layer number. In fact, the bandgap increases with the increasing of the interlayer distance, due to the energy shift of conduction and valence bands dominated by Se-pz
orbitals. According to the comparison with the available experimental data, the vdW corrections vdW-DF and rVV10 gave the most accurate results. Moreover, the control of the interlayer distance via vertical compressive strain led to the bandgap tuning of semiconductor PtSe2 BL. Indeed, a semi-metal character of PtSe2 BL can be obtained under 17% vertical strain. Our work shows a deep understanding of the correlation between the structural and electronic properties, and thus a possibility to tune the bandgap by strain means.
Intelligent recognition and automatic localization of pipeline welds based on multi-vision system
Authors: Li Haijun , Yang Linghui , Long Changyu , Cheng Yijia , Fan Yiyuan , Zhu Jigui
Published: October 2024

Currently, the leakage detection of spacecraft pipeline welds relies on manual point-by-point inspection using a detection gun, which is inefficient and inadequate for the automation needs of spacecraft production. However, the accurate recognition and precise localization of widely distributed and small pipeline welds are crucial for automated detection. Therefore, this paper proposes a multi-vision detection and localization system that integrates global and local information, considering both comprehensive global 3D search and high-precision local 3D measurement. The improved YOLOv8 model is employed for pipeline weld recognition, which improves the recognition rate of welds. Based on the deep learning recognized and segmented welds, this paper proposes stereo matching and segmentation extraction methods for 3D localization and pipeline orientation determination. Additionally, the system integrates a robot to perform automated point-by-point inspection of welds within the area without collisions. The experimental results demonstrate the effectiveness of the improved YOLOv8 and the proposed methods for 3D weld localization and pipeline orientation determination. The maximum deviation of the spatial distance of fine weld positioning is 0.20 mm, and the repeatability of the 3D coordinates is around 0.1 mm. The system can perform precise localization and detection, meeting the requirements for automatic weld recognition and localization.
A highly naturalistic facial expression generation method with embedded vein features based on diffusion model
Authors: Song Hong-Jun , Wang Ying-Li , Ma Hong-Bin , Xu Qing-Huan , Zhang Jing
Published: October 2024

Facial expression generation technology has achieved notable progress in computer vision and artificial intelligence. However, challenges persist regarding background consistency, expression clarity, and detailed representation. Additionally, the instability of generative adversarial networks (GANs) during training affects both image quality and diversity. While diffusion models have demonstrated potential advantages over GANs, research on controllable expression generation remains limited. To address these challenges, this paper proposes a highly natural facial expression generation method based on denoising diffusion implicit models (DDIM) with embedded vein features. This approach avoids adversarial training by employing gradual diffusion to generate specific expressions, thereby enhancing both the diversity and authenticity of the images. Vein features are introduced and embedded within the generated expression images to protect the intellectual property (IP) of algorithm-generated digital resources. Firstly, image and expression text guide words are combined as conditional inputs to improve the authenticity and diversity of the generated images. Secondly, a classification coding network is introduced to guide expression generation, thus enhancing the accuracy and consistency of the produced expressions. Furthermore, this paper proposes a vein feature fusion method based on multi-directional local dynamic feature coding operator and integrates DDIM with frequency-domain watermarking technology to achieve image IP protection. Experimental results demonstrate the effectiveness of this method across several public datasets, including FFHQ, CelebA, FV-USM, and SDUMLA-HMT. Notably, in the CelebA dataset, the average expression recognition rate increased by 11.41%, with a 100.00% recognition rate for happy expressions. The generated expression images exhibit a high degree of authenticity and consistency, and the video conversion tests reveal a natural and smooth effect. These results confirm that this method not only advances facial expression generation technology but also significantly enhances the steganographic protection of images.
Frequency noise suppression of the high-power pumping laser in the SERF atomic magnetometer
Authors: Wang Guiqi , Duan Lihong , Ma Ning , Liu Qingbo , Hu Zeyi
Published: October 2024

A high-sensitivity spin exchange relaxation free (SERF) atomic magnetometer based on a noise-suppressed master oscillator power amplifier (MOPA) system is demonstrated. The spectrum and frequency noise of the laser are measured and it is proved that the frequency noise in the MOPA system is affected by the amplified spontaneous emission (ASE) stimulated from the power amplifier. The frequency noise of the MOPA system is decreased by filtering out the ASE background in the spectrum through a bandpass filter. The sensitivity of the SERF atomic magnetometer is improved by using the frequency noise-suppressed MOPA system as a pumping laser. This method can also be applied to other precision measurement fields based on MOPA systems that have high requirements for frequency noise of lasers.