bluuebunny/crossref_metadata_2025 huggingface dataset:
Rethinking the environmental Kuznets curve hypothesis across 214 countries: the impacts of 12 economic, institutional, technological, resource, and social factors
Authors: Wang Qiang , Li Yuanfan , Li Rongrong
Published: February 2024

Research over the past three decades has provided rich empirical evidence for the inverted U-shaped EKC theory, but current problems facing advancing climate mitigation actions require us to re-examine the shape of global EKC rigorously. This paper examined the N-shaped EKC in a panel of 214 countries with 12 traditional and emerging variables, including institutions and risks, information and communication technology (ICT), artificial intelligence(AI), resource and energy use, and selected social factors. The two-dimensional Tapio decoupling model based on N-shaped EKC to group homogeneous countries is developed to explore the inter-group heterogeneous carbon emission effects of each variable. Global research results show that the linear and cubic terms of GDP per capita are significantly positive, while the quadratic term is significantly negative, regardless of whether additional variables are added. This means the robust existence of an N-shaped EKC. Geopolitical risk, ICT, and food security are confirmed to positively impact per capita carbon emissions, while the impact of composite risk, institutional quality, digital economy, energy transition, and population aging are significantly negative. The impact of AI, natural resource rents, trade openness, and income inequality are insignificant. The inflection points of the N-shaped EKC considering all additional variables are 45.08 and 73.44 thousand US dollars, respectively. Combining the turning points and the calculated decoupling coefficients, all countries are categorized into six groups based on the two-dimensional decoupling model. The subsequent group regression results show heterogeneity in the direction and magnitude of the carbon emission impacts of most variables. Finally, differentiated carbon emission reduction strategies for countries in six two-dimensional decoupling stages are proposed.
Windmill-shaped device enhances magnetic sensor performance
Authors: Thompson Avery
Published: February 2024

The design allows sensors to detect weaker magnetic fields and could be built into small chips for nearly endless uses.
Using machine learning to improve efficiency of acoustic nanogenerators
Authors: Thompson Avery
Published: February 2024

Machine learning algorithms can effectively analyze data and identify key parameters for performance optimization.
Instrument with an ultra-wide dynamic detection range for the optical counting and sizing of individual particles in suspensions
Authors: Hussels Martin , Lichtenfeld Heinz , Woehlecke Holger , Wollik Elia , Lerche Dietmar
Published: February 2024

The characterization of dispersions, suspensions, and emulsions is important in a wide range of scientific applications and industries. Samples can consist of different materials and a wide range of particle sizes and concentrations. A single particle sizing and counting instrument with a dynamic detection range of ≥6 decades has been developed to detect single nano- and microparticles in aqueous suspensions based on light scattering measured in two directions. Hydrodynamic focusing is employed for particle separation and to provide stable conditions for light scattering detection. This gives the advantage of size resolution in the nm range, allowing, e.g., number based size distributions, classification of nanomaterials, determination of particle agglomerates, developments for dispersion stability analysis, or cutoff of filter media. In addition, concentration determination is based on sample volume measurement with <20 nl measurement uncertainty. We present results of particle detection in a size range from approximately above 40 nm for gold nanoparticles to 8 μm for polystyrene particles using a prototyped instrument of the LUMiSpoc® series produced by LUM GmbH. The data obtained demonstrate the advantages of single-particle detection, particularly for characterizing polydisperse systems, such as precise particle sizing in the nanometer range through light scattering intensity based on Mie scattering theory. In addition, we present particle concentration data based on the integrated measurement of sample volume, which allows particle concentration to be determined with an uncertainty of 2.5% (95% confidence interval). To achieve such small uncertainties, dilution series measurements must be used to correct for coincidence losses and particle adhesion.
Experimental and numerical analysis of the physical characteristics of natural and ventilated supercavitating flows
Authors: Pham Van-Duyen , Hong Ji-Woo , Ahn Byoung-Kwon
Published: February 2024

In this experimental and numerical study, we investigate the physical characteristics of a supercavitating flow generated behind a disk-shaped cavitator under both natural and ventilated conditions, an area of research that has not been thoroughly examined. Initially, the experiment is conducted within a cavitation tunnel employing a forward-facing model, complemented by high-speed visualization techniques. Subsequently, an unsteady Reynolds-averaged Navier–Stokes approach is adopted to conduct numerical simulations along with the k–ε turbulent model and Ffowcs Williams–Hawkings (FW–H) methods. The outcomes of the study demonstrate that when considering fixed cavitation numbers, the profiles of natural and ventilated cavities are consistent. Under constant flow conditions, the introduction of ventilating air leads to a discernible reduction in hydroacoustic characteristics in the high-frequency spectrum and has the potential to improve flow stability behind the cavitator. The numerical results offer insight into the behaviors of the water, vapor, and ventilation air. In the foamy cavity stage, all the considered phases (water, vapor, and ventilation air) coexist inside the cavity. Upon the formation of a transparent supercavity, the ventilation air primarily gathers around the ventilation holes and the surrounding gas-leakage region. Meanwhile, the vaporous gas is dominant and is concentrated predominantly in the central region of the supercavity. The findings extracted from this study represent a significant advancement in our understanding of the intricacies of supercavities under ventilated and vaporous conditions. These insights hold the potential to drive groundbreaking innovations in the design and control of supercavitating vehicles.
Disentangling optical effects in 3D spiral-like, chiral plasmonic assemblies templated by a dark conglomerate liquid crystal
Authors: Szepke Dorota , Zarzeczny Mateusz , Pawlak Mateusz , Jarmuła Paweł , Yoshizawa Atsushi , Pociecha Damian , Lewandowski Wiktor
Published: February 2024

Chiral thin films showing electronic and plasmonic circular dichroism (CD) are intensively explored for optoelectronic applications. The most studied chiral organic films are the composites exhibiting a helical geometry, which often causes entanglement of circular optical properties with unwanted linear optical effects (linearly polarized absorption or refraction). This entanglement limits tunability and often translates to a complex optical response. This paper describes chiral films based on dark conglomerate, sponge-like, liquid crystal films, which go beyond the usual helical type geometry, waiving the problem of linear contributions to chiroptical electronic and plasmonic properties. First, we show that purely organic films exhibit high electronic CD and circular birefringence, as studied in detail using Mueller matrix polarimetry. Analogous linear properties are two orders of magnitude lower, highlighting the benefits of using the bi-isotropic dark conglomerate liquid crystal for chiroptical purposes. Next, we show that the liquid crystal can act as a template to guide the assembly of chemically compatible gold nanoparticles into 3D spiral-like assemblies. The Mueller matrix polarimetry measurements confirm that these composites exhibit both electronic and plasmonic circular dichroisms, while nanoparticle presence is not compromising the beneficial optical properties of the matrix.
Mitigation of carrier trapping effects on carrier lifetime measurements with continuous-wave laser illumination for Pb-based metal halide perovskite materials
Authors: Lobo Ntumba , Matt Gebhard J. , Osvet Andres , Shrestha Shreetu , Kanak Andrii , Fochuk Petro , Brabec Christoph J. , Kato Masashi
Published: February 2024

We investigated the impact of carrier trapping on the carrier lifetime of metal halide perovskite materials, which are key to solar cell production. We examined NH3CH3PbI3 (MAPbI3), NH3CH3PbBr3 (MAPbBr3), and CsPbBr3 using continuous-wave (CW) laser illumination during microwave photoconductivity decay (μ-PCD) measurements. Traditional pulsed light excitation falls short of mirroring solar cell operating conditions, owing to carrier trapping. Implementing CW laser illumination provides a more accurate estimation of the carrier lifetimes under operational conditions. With an increased photon flux from the CW laser, the μ-PCD decay curves changed, indicating reduced recombination via traps. The experiments revealed extended carrier lifetimes under continuous light for the MAPbI3 polycrystal. This suggests that CW lasers can mitigate trapping effects on carrier lifetime measurements. For the other samples, carrier trapping had a negligible effect on the measured carrier lifetimes. We believe that these findings will aid in the design of perovskite-based devices.
Taming the third order cumulant approximation to linear optical spectroscopy
Authors: Allan Lucas , Zuehlsdorff Tim J.
Published: February 2024

The second order cumulant method offers a promising pathway to predicting optical properties in condensed phase systems. It allows for the computation of linear absorption spectra from excitation energy fluctuations sampled along molecular dynamics (MD) trajectories, fully accounting for vibronic effects, direct solute–solvent interactions, and environmental polarization effects. However, the second order cumulant approximation only guarantees accurate line shapes for energy gap fluctuations obeying Gaussian statistics. A third order correction has recently been derived but often yields unphysical spectra or divergent line shapes for moderately non-Gaussian fluctuations due to the neglect of higher order terms in the cumulant expansion. In this work, we develop a corrected cumulant approach, where the collective effect of neglected higher order contributions is approximately accounted for through a dampening factor applied to the third order cumulant term. We show that this dampening factor can be expressed as a function of the skewness and kurtosis of energy gap fluctuations and can be parameterized from a large set of randomly sampled model Hamiltonians for which exact spectral line shapes are known. This approach is shown to systematically remove unphysical contributions in the form of negative absorbances from cumulant spectra in both model Hamiltonians and condensed phase systems sampled from MD and dramatically improves over the second order cumulant method in describing systems exhibiting Duschinsky mode mixing effects. We successfully apply the approach to the coumarin-153 dye in toluene, obtaining excellent agreement with experiment.
Phase-field-based finite element model for two-phase ferrofluid flows
Authors: Yuan Pengfei , Cheng Qianxi , Hu Yang , He Qiang , Huang Weifeng , Li Decai
Published: February 2024

In this study, we propose a phase-field-based finite element model to simulate two-phase ferrofluid flows in two and three dimensions. The proposed model combines the Cahn–Hilliard equation to handle the phase field, the Poisson equation to account for magnetics, and the Navier–Stokes equation to characterize fluid flow. To efficiently handle this coupling, we present a linear, totally decoupled numerical scheme, which involves solving four separate equations independently, namely, a linear elliptic system for the phase function, a Poisson equation for the magnetic potential, a linear elliptic equation for the velocity, and a Poisson equation for the pressure. To assess the accuracy, applicability, and numerical stability of the model, we conduct simulations for several typical problems. These include investigating the deformation of a ferrofluid droplet under a two-dimensional uniform magnetic field model, the bubble coalescence in ferrofluids under a three-dimensional uniform magnetic field model, the collision of two ferrofluid droplets under two-dimensional shear flow, and the two-dimensional interfacial instability of a ferrofluid. The numerical results confirm the model's capability to robustly simulate multiphase flow problems involving high-density and high-viscosity ratios, both in two- and three-dimensional problems. Moreover, the model effectively captures fundamental phenomenological features of two-phase ferrofluid flows under large topological changes such as the Rosensweig instability.
Experimental study of the effects of isolated roughness elements on the stability and transition of a hypersonic boundary layer on a flat plate
Authors: Liu Shicheng , Dong Hao , Jiang Yinglei
Published: February 2024

Surface roughness elements on hypersonic vehicles can cause early boundary layer transition, increasing wall skin friction and heat flux and affecting aircraft range and thermal protection systems. Accurate prediction of the transition caused by these roughness elements is crucial for the design of hypersonic vehicles. In this work, wind tunnel experiments on isolated roughness-induced boundary layer transition at Ma = 6 are conducted. Infrared thermography and high-frequency pressure sensors are utilized to investigate the effects of different roughness element configurations (cylindrical, diamond, ramp) on the hypersonic boundary layer instability and transition. The experimental results show that all three roughness elements can effectively enhance the generation of second mode waves and promote boundary layer transition. Compared to smooth surfaces, they exhibit similar frequency band range, faster growth, and earlier saturation. Among them, the ramp roughness element most effectively triggers the boundary layer transition, with a relatively small heat flux increase. Furthermore, bispectral analysis illustrates that all three roughness elements undergo self-interactions that lead to spectral broadening, ultimately resulting in boundary layer transitions.
Challenges in molecular dynamics simulations of heat exchange statistics
Authors: Wang Jonathan J. , Gerry Matthew , Segal Dvira
Published: February 2024

We study heat exchange in temperature-biased metal–molecule–metal molecular junctions by employing the molecular dynamics simulator LAMMPS. Generating the nonequilibrium steady state with Langevin thermostats at the boundaries of the junction, we show that the average heat current across a gold–alkanedithiol–gold nanojunction behaves physically, with the thermal conductance value matching the literature. In contrast, the full probability distribution function for heat exchange, as generated by the simulator, violates the fundamental fluctuation symmetry for entropy production. We trace this failure back to the implementation of the thermostats and the expression used to calculate the heat exchange. To rectify this issue and produce the correct statistics, we introduce single-atom thermostats as an alternative to conventional many-atom thermostats. Once averaging heat exchange over the hot and cold thermostats, this approach successfully generates the correct probability distribution function, which we use to study the behavior of both the average heat current and its noise. We further examine the thermodynamic uncertainty relation in the molecular junction and show that it holds, albeit demonstrating nontrivial trends. Our study points to the need to carefully implement nonequilibrium molecular dynamics solvers in atomistic simulation software tools for future investigations of noise phenomena in thermal transport.
Local-environment-guided selection of atomic structures for the development of machine-learning potentials
Authors: Li Renzhe , Zhou Chuan , Singh Akksay , Pei Yong , Henkelman Graeme , Li Lei
Published: February 2024

Machine learning potentials (MLPs) have attracted significant attention in computational chemistry and materials science due to their high accuracy and computational efficiency. The proper selection of atomic structures is crucial for developing reliable MLPs. Insufficient or redundant atomic structures can impede the training process and potentially result in a poor quality MLP. Here, we propose a local-environment-guided screening algorithm for efficient dataset selection in MLP development. The algorithm utilizes a local environment bank to store unique local environments of atoms. The dissimilarity between a particular local environment and those stored in the bank is evaluated using the Euclidean distance. A new structure is selected only if its local environment is significantly different from those already present in the bank. Consequently, the bank is then updated with all the new local environments found in the selected structure. To demonstrate the effectiveness of our algorithm, we applied it to select structures for a Ge system and a Pd13H2 particle system. The algorithm reduced the training data size by around 80% for both without compromising the performance of the MLP models. We verified that the results were independent of the selection and ordering of the initial structures. We also compared the performance of our method with the farthest point sampling algorithm, and the results show that our algorithm is superior in both robustness and computational efficiency. Furthermore, the generated local environment bank can be continuously updated and can potentially serve as a growing database of feature local environments, aiding in efficient dataset maintenance for constructing accurate MLPs.
Near-edge x-ray absorption fine structure spectra and specific dissociation of small peptoid molecules
Authors: Chiang Yu-Ju , Huang Wan-Chou , Han Chou-Hsun , Liu Chen-Lin , Tsai Cheng-Cheng , Hu Wei-Ping
Published: February 2024

In this study, the total ion yield near-edge x-ray absorption fine structure spectra of four similar peptoid molecules, which differ in the numbers and positions of methyl groups, were investigated experimentally and theoretically. At each excitation energy, the intensity and branching ratio of each ionic product were measured. At a few resonant excitation energies, a specific dissociation of the C–CO bond at the nitrogen and oxygen K-edges and of the N–CO bond at the carbon K-edge was dominant, which correlated well with the predicted destination antibonding orbitals of the core electron excitation. These specific dissociation mechanisms of small peptoid molecules could provide insights into similar phenomena that occur in peptide molecules.
(Ga,Mn)N—Epitaxial growth, structural, and magnetic characterization—Tutorial
Authors: Piskorska-Hommel Edyta , Gas Katarzyna
Published: February 2024

The spin control possibility and its application in optoelectronic devices began an intensive research into its utilization, in particular, in the wide-gap semiconductors such as GaN doped with transition metal ions. Due to a strong p–d hybridization in Ga1−xMnxN, the Curie temperature above 300 K was already expected for x = 5%, providing that the free hole concentration necessary for the hole-mediated ferromagnetism exceeds 1020 cm−3. In this context, the development of non-equilibrium techniques enabled the engineering high-quality epitaxial layers of (Ga,Mn)N exhibiting uniform ferromagnetism at low-end cryogenic temperatures. The Tutorial is focused on the molecular beam epitaxy growth method of the Mn-enriched GaN magnetic semiconductors, summarizes the (Ga,Mn)N structural and electronic studies, and explains fundamental ferromagnetic properties, including the determination of the Mn concentration and the Curie temperature based on magnetic measurements. Most studies reveal the homogenous substitution of Mn3+ ions in the GaN matrix. Nevertheless, achieving room-temperature ferromagnetism still remains a challenge. Therefore, in the Tutorial, future research is suggested that can help obtain the homogenous ferromagnetism in (Ga,Mn)N at much elevated temperatures.
Roughness effects on compressible turbulent boundary layers under different Mach numbers and wall temperature conditions
Authors: Wang Yuhan , Gao Zhenxun
Published: February 2024

Compressible turbulent boundary layers over a zero-pressure gradient flat plate with three-dimensional sinusoidal roughness are simulated by direct numerical simulation. The roughness effects on surface drag, velocity transformation, and turbulence fluctuation characteristics are analyzed in a wide range of Mach numbers (Ma∞ = 2.25–7.25) and different ratios of wall-to-recovery temperature (Tw/Taw = 0.43 and 0.84) conditions. It is found that the roughness significantly amplifies the surface drag coefficient due to the extra pressure drag induced by roughness, and the relative increase in surface drag induced by the roughness rises by 31.1% when Ma∞ changes from 2.25 to 7.25. Current compressible velocity transformations cannot make the logarithmic region of velocity profiles independent of Tw/Taw conditions for rough cases due to the strong wall heat transfer effect below roughness peak. Therefore, a new velocity transformation (Uρt+) is proposed to make the logarithmic region of Uρt+ profiles and roughness induced a downward shift of Uρt+ profiles (ΔUρt+) in a logarithmic region independent of Ma∞ and Tw/Taw conditions. Further numerical experiments validate that, in hypersonic boundary layers, the relation between ΔUρt+ and equivalent sand-grain roughness height Reynolds number still satisfies the roughness function proposed earlier for incompressible flows. Moreover, roughness significantly changes the distribution of mean turbulent kinetic energy (TKE) in compressible turbulent boundary layers: TKE is suppressed at the bottom of roughness, while reaching its maximum at the roughness peak, which is 50%–60% larger than that in smooth case. Finally, the expansion/compression wave patterns induced by roughness alter the turbulence fluctuations in outer layer.
Thermoelectric properties of sintered Ba2AgSi3 crystals and search for impurities to control conductivity type by first-principles calculation
Authors: Kajihara K. , Koda Y. , Ishiyama T. , Aonuki S. , Toko K. , Honda S. , Mesuda M. , Suemasu T.
Published: February 2024

In this study, the basic properties of Ba2AgSi3 were investigated in detail from both experimental and computational viewpoints. Polycrystalline Ba2AgSi3 formed by an arc-melting apparatus under an argon atmosphere was ground into powders, and then powder samples were sintered using the spark plasma sintering method. Both n-type and p-type samples were obtained. This may be due to a slight deviation from the stoichiometric composition. The energy bandgap of Ba2AgSi3 was measured to be around 0.17 eV from the temperature dependence of electrical conductivity and was in agreement with that by first-principles calculations. Sintered samples exhibited a high Seebeck coefficient of −273 μV K−1 and a high power factor of 0.38 mW m−1 K−2 at 307 K for n-type samples. They were 217 μV K−1 and 0.23 mW m−1 K−2, respectively, at 320 K for p-type samples. The electronic structures of impurity-doped Ba2AgSi3 were also discussed using first-principles calculations to investigate the insertion site of impurity atoms. The calculations suggest that the substitution of B (P) at any Si site shifts the Fermi level and transforms it into p-type (n-type) semiconductors. On the other hand, substitution of Ba or Ag sites with B or P is unlikely to occur in terms of formation energy.
Effect of shock impedance of mesoscale inclusions on the shock-to-detonation transition in liquid nitromethane
Authors: Wang Ziwei , Xue Kun , Mi Xiaocheng
Published: February 2024

Two-dimensional, meso-resolved numerical simulations are performed to investigate the effect of shock impedance of mesoscale inclusions on the shock-to-detonation transition (SDT) in liquid nitromethane (NM). The shock-induced initiation behaviors resulting from the cases with NM mixed with randomly distributed, 100-μm-sized air-filled cavities, polymethyl methacrylate (PMMA), silica, aluminum (Al), and beryllium (Be) particles with various shock impedances are examined. In this paper, hundreds of inclusions are explicitly resolved in the simulation using a diffuse-interface approach to treat two immiscible fluids. Without using any empirically calibrated, phenomenological models, the reaction rate in the simulations only depends on the temperature of liquid NM. The sensitizing effect of different inclusion materials can be rank-ordered from the weakest to the strongest as PMMA → silica → air → Al → Be in the hot-spot-driven regime of SDT. Air-filled cavities have a more significant sensitizing effect than silica particles, which is in agreement with the experimental finding. For different solid-phase inclusions, hot spots are formed by Mach reflection upon the interaction between the incident shock wave and the particle. The sensitizing effect increases roughly with the shock impedance of the inclusion material. More details of the hot-spot formation process for each solid-phase inclusion material are revealed via zoom-in simulations of a shock passing over a single particle.
A general integration kernel formulation for immersed boundary method
Authors: Jiang Yiyang , Xie Fangfang , Ji Tingwei , Zheng Yao
Published: February 2024

This study proposes a new robust and accurate immersed boundary method for the immersion of solid bodies within a fluid with a Cartesian grid. The present method introduces the signed distance fields to recognize the immersed geometry contours, eliminating the need of Lagrangian points. To fully maximize the advantages offered by signed distance fields, a general integration kernel formulation is introduced into the direct forcing method to replace the conventional regularized delta function. With the combination of signed distance fields and kernel function, an interpolation along the radial direction instead of three-dimensional directions is feasible, which further reduces the extra calculation cost involved by immersed boundary method. The numerical results at low Reynolds numbers are compared to experimental and previous numerical results, which shows the efficiency and accuracy of this new method. Upon thorough validation, the proposed method in this paper demonstrates excellent performance across various scenarios, including static and moving cases as well as two- and three-dimensional configurations. And our method greatly reduces the cost of pretreatment of immersed geometry contours and apparently improves the convenience of the method.
Measuring residual stresses in individual on-chip interconnects using synchrotron nanodiffraction
Authors: Zhang Yaqian , Du Leiming , Bäcke Olof , Kalbfleisch Sebastian , Zhang Guoqi , Vollebregt Sten , Hörnqvist Colliander Magnus
Published: February 2024

As the dimensions of interconnects in integrated circuits continue to shrink, an urgent need arises to understand the physical mechanism associated with electromigration. Using x-ray nanodiffraction, we analyzed the stresses in Blech-structured pure Cu lines subjected to different electromigration conditions. The results suggest that the measured residual stresses in the early stages of electromigration are related to relaxation of stresses caused by thermal expansion mismatch, while a developing current-induced stress leads to reductions in the residual stress after longer test times. These findings not only validate the feasibility of measuring stress in copper lines using nanodiffraction but also highlight the need for a further understanding, particularly through in situ electromigration experiments with x-ray nanodiffraction analysis.
Steady flow of non-Newtonian fluids: Momentum and heat transfer around a rectangular cylinder
Authors: Verma G. , Bharti C. K. , Barman R. N.
Published: February 2024

This research aims to explore the impact of cross-sectional aspect ratio (AR), power-law index (n), Reynolds number (Re), and Prandtl number (Pr) on convective heat transfer rates using the Nusselt number (Nu) and coefficient of drag (CD) as a key metric. Numerical simulations employ the ANSYS FLUENT solver with the finite volume method. The SIMPLE scheme couples pressure and velocity, and the QUICK differencing scheme discretizes convective terms. This study varies the aspect ratio by adjusting the length-to-width ratio (b/D) to explore different configurations of AR = 1–5 and Pr = 0.7, 1, and 7, which investigate 5 ≤ Re ≤ 10 and 0.2 ≤ n ≤ 1, respectively. An increase in the Reynolds number is observed to diminish the thermal boundary layer thickness, resulting in an escalation of heat transfer rates. Additionally, the Nusselt number exhibits an upward trend with an increase in the Prandtl number. The investigation reveals a decrease in Nu with an increase in both AR and n. Specifically, higher aspect ratios and power-law indices are associated with reduced heat transfer rates. The AR emerges as a significant factor, influencing the coefficient of drag, with CD values showing an increase as AR rises, particularly at low Re. Moreover, CD is found to increase with an elevation in the n value. This study explores new ground by investigating power-law fluid behavior and heat transfer phenomenon across varied aspect ratios. These insights not only enhance the design of heat transfer systems with non-Newtonian fluids but also pave the way for future research in this less explored domain.
How supranational literary prizes shape translation flows
Authors: Janssens Eva
Published: February 2024

This article explores how literary prizing shapes translation flows by comparing bibliographic data on the
translations of prize-winning books. It focuses on two prizes in particular, the Booker Prize and the European Union Prize for
Literature (EUPL), both of which generate significant numbers of translations but for very different reasons. The article develops
the idea of ‘prizing logics’ to help explain these differences, singling out factors that appear to play a role: (1) the prize’s
translation policy (especially important for the EUPL) and (2) the prize’s prestige and focus on commercial success (particularly
relevant for the Booker). It shows that translations of EUPL winners are largely a result of state support, which is linked to the
prize’s aim of spreading European diversity and reinforcing unity through literature, while the Booker is more focused on literary
quality and stimulating commercial success, thereby leading to many translations of its winners.
L-Mn dielectronic recombination of cerium ions in a room-temperature EBIT
Authors: Biela-Nowaczyk W , Grilo F , Amaro P , Warczak A
Published: February 2024

We explore the dielectronic recombination structures at the electron beam ion trap at Jagiellonian University in Cracow, emited by cerium that is produced by the high-current cathode made of iridium and cerium. Small amounts of these elements evaporate from the cathode and form low-intensity admixtures within the electron-ion plasma in the EBIT. Their presence and specific ionic population can be observed by examining the spectral characteristics resulting from the DR process. Results have been compared with flexible atomic code calculations, working in unresolved transition array mode, providing identification of the charge states. Here we show that this mode provides quick calculations of very complex data with enough reliability for experimental comparison. These observations highlight which DR features and corresponding charge states that should be present in spectra obtained in EBITs with similar cathode specifications.
Remarkably enhancing dielectric permittivity and suppressing loss of PVDF via incorporating metal nanoparticles decorated glass fibers
Authors: Zhu Linwei , Yang Yujie , Li Yuchao , Shi Zhicheng , Bie Xiaohan , Yuan Yuan , Fan Runhua
Published: February 2024

Dielectrics with high permittivity and low dielectric loss have so far received considerable attention because of their wide applications in various electronic devices. However, the enhanced permittivity of dielectrics is always accompanied by an increase in loss. In this work, targeting at enhancing the permittivity of poly(vinylidene fluoride) (PVDF) without elevating loss, gold nanoparticles (Au NPs) decorated glass fibers (GF) are incorporated into the PVDF, forming a unique design of Au@GF/PVDF composites. The effects of gold nanoparticle content, calcination temperature, and hot-pressing pressure on the dielectric properties are studied. Interestingly, for the composite with gold sputtering time of 3 min, a remarkable dielectric enhancement of 430% (i.e. from 7.8 to 33.5 at 10 kHz) along with an obvious loss suppression of 56% (i.e. from 0.0353 to 0.0198) are concurrently achieved. It is believed that, the increase in permittivity is mainly attributed to the Maxwell–Wagner–Sillars effect of effective micro-capacitors and cluster polarization of gold nanoparticles while the suppressed loss is originated from the intrinsic low loss of GF and the Coulomb-blockade effect of gold nanoparticles. This work offers a promising strategy to simultaneously enhance the permittivity and suppress the loss of dielectric materials.
Parallel compensation of anisoplanatic aberrations in patterned photostimulation for two-photon optogenetics
Authors: Jin Cheng , Liu Chi , Kong Lingjie
Published: February 2024

Two-photon optogenetics becomes an indispensable technique in deciphering neural circuits recently, in which patterned photostimulation is generally adopted due to its low time delay and jitter, as well as its finely sculpting ability in space. However, optical aberrations in light propagation often deteriorates patterned photostimulation, leading to decreased intensity of patterns and thus reduced excitation efficiency. Considering anisoplanatic aberrations at different positions, only correcting aberrations at one position may aggravate aberrations at other positions. Here we propose a parallel aberration compensation based Gerchberg–Saxton (PAC-GS) algorithm for generating multiple holographic extended patterns with anisoplanatic aberrations compensated simultaneously. As an example, we demonstrate that PAC-GS is able to parallelly compensate anisoplanatic aberrations of multiple holographic patterns under gradient index (GRIN) lens, thus effectively improving the intensity of each pattern, promising for two-photon optogenetics in deep biological tissues with GRIN lens.
Magnetic field directed assembly of magnetic non-spherical microparticles
Authors: Piltaver Ivna Kavre , Vilfan Andrej , Kostevc Gregor , Kralj Slavko , Babič Dušan
Published: February 2024

This study reports on the fabrication and assembly of anisotropic microparticles as versatile building blocks for directed magnetic assemblies. Although spherical microparticles have received extensive attention, the assembly of non-spherical magnetic microparticles remains underexplored. Herein, we present a fabrication approach that utilizes photolithography and soft lithography to create prism-shaped magnetic microparticles. In order to investigate their assembly, a switching rotating magnetic field was employed. To support our experimental findings, a numerical model which takes into account the magnetic dipole moments induced by the field of other particles was developed. This model helps in understanding the forces and torques governing particle behavior during assembly. Simulations were conducted using the numerical model to complement our experimental findings. In the two particle experiments, attractive magnetic interactions led to various configurations depending on initial positions. For three particles, a tip-to-tip configuration suggested closed or stable ring-like structures. Our work highlights the feasibility of producing highly responsive, non-spherical magnetic microparticles and their potential for assemblies. The versatile fabrication method, coupled with the added degree of freedom conferred by prismatic shapes, opens promising avenues for applications in biology and material science.
Magnetization direction-controlled topological band structure in TlTiX (X = Si, Ge) monolayers
Authors: Huang Keer , Li Lei , Zhao Wu , Wang Xuewen
Published: February 2024

The quantum anomalous Hall (QAH) insulator is a vital material for the investigation of emerging topological quantum effects, but its extremely low working temperature limits experiments. Apart from the temperature challenge, effective regulation of the topological state of QAH insulators is another crucial concern. Here, by first-principles calculations, we find a family of stable two-dimensional materials TlTiX (X = Si, Ge) are large-gap QAH insulators. Their extremely robust ferromagnetic (FM) ground states are determined by both the direct- and super-exchange FM coupling. In the absence of spin–orbit coupling (SOC), there exist a spin-polarized crossing point located at each K and Kʹ points, respectively. The SOC effect results in the spontaneous breaking of C
2 symmetry and introduces a mass term, giving rise to a QAH state with sizable band gap. The tiny magnetocrystalline anisotropic energy (MAE) implies that an external magnetic field can be easily used to align magnetization deviating from z direction to the x–y plane, thereby leading to a transformation of the electronic state from the QAH state to the Weyl half semimetals state, which indicate monolayers TlTiX (X = Si, Ge) exhibit a giant magneto topological band effect. Finally, we examined the impact of stress on the band gap and MAE, which underlies the reasons for the giant magneto topological band effect attributed to the crystal field. These findings present novel prospects for the realization of large-gap QAH states with the characteristic of easily modifiable topological states.
A multi-source subdomain adaptation fault diagnosis method based on unidirectional movement of the target domain
Authors: Ma Tianyu , Li Zhipeng , Yang Dan , Tang Junjie , Liu Jinping
Published: February 2024

The traditional domain adaptation method for fault diagnosis of axial fans faces two main problems: (1) source domain moves to target domain makes the source feature distribution changed; (2) the narrow decision boundary of source domain features leads to misclassification of target samples. Therefore, a multi-source subdomain adaption fault diagnosis method based on unidirectional movement of the target domain is proposed. The method uses triplet-center loss to improve the discrimination of target domain samples, which reducing intra-class distance and increasing inter-class distance of source domain features; extracting the domain invariant feature of the target samples by asymmetric adversarial and improved subdomain feature distance measurement; the cosine similarity is used to align the classifiers’ outputs of different source domains; the mean value of all classifiers’ outputs are used as pseudo labels, and the pseudo labels are optimized by maximum entropy to improve their reliability. A large number of experiments show that this method has a significant effect on solving the problem of cross conditions fault diagnosis.
A clustering multi-stage training transfer learning framework for cross simulation domain and experimental domain fault diagnosis
Authors: Yu Shubo , Liu Zhansheng , Zhao Chen , Lv Dongfang
Published: February 2024

Deep learning methods have demonstrated remarkable achievements in the field of fault diagnosis for rotating machinery. However, their effectiveness heavily relies on high-quality labeled samples, which presents a significant challenge owing to the limited availability of such data in engineering applications. To address this realistic issue, we propose a novel simulation-driven transfer learning model called the clustering multi-stage training transfer learning framework (CMSTL) for fault diagnosis of rolling bearings. The fundamental concept of the proposed method is to utilize simulation data as a substitute for labeled actual device data and integrate the suggested clustering learning and multistage training strategies to extract domain-independent and fault-discriminative features from simulation and experimental domains. Specifically, the clustering learning strategy is embedded into the CMSTL model to encourage the feature extractor to acquire distinguishable features associated with different categories while eliminating domain-specific knowledge, which enables samples near the classification decision boundary to cluster towards their respective clustering centers. Additionally, the proposed multistage learning strategy leverages the model trained with a certain level of accuracy in the first stage to annotate actual device samples, thereby enhancing both the precision of the pseudo-label for real data and the overall training stability of the model. The effectiveness and superiority of the proposed method were validated using both artificially damaged and run-to-failure datasets. The comparative analysis results demonstrate that the CMSTL method exhibits a minimum 2.2% improvement in fault diagnosis accuracy and enhances the clustering capability compared to other advanced transfer learning fault diagnosis methods.
Isolation and identification of rolling bearing compound faults based on adaptive periodized singular spectrum analysis and Rényi entropy
Authors: Li Shengqiang , Yan Changfeng , Hou Yunfeng , Meng Jiadong , Wen Tao
Published: February 2024

Due to the coupling of multiple fault feature information and contamination of heavy background noise, it is a challenging task to accurately identify rolling bearing compound faults (RBCFs). A method for isolating and identifying the RBCF is proposed by integrating adaptive periodized singular spectrum analysis (APSSA) with Rényi entropy (RE). The adaptive selection of the embedding dimension of the Hankel matrix in APSSA without setting parameters empirically is proposed, and a selection criterion for singular values is established to preprocess the vibration signals of the rolling bearing and enhance the periodic component of the fault. An RE-based threshold value is introduced to further isolate and decouple the impulse segments of the vibration signal in the time domain. By considering the inner raceway fault, outer raceway fault, ball fault, and skidding, a comprehensive simulation model of the compound fault is constructed by the response mechanism of different excited resources. Simulated and experimental data are applied to validate the effectiveness and practicability of the proposed method. The results demonstrate that the RBCF can be identified correctly by the proposed method under strong background noise.
Construction of multi-features comprehensive indicator for machinery health state assessment
Authors: Ding Lansa , Wei Xiaoyi , Wang Dezheng , Chen Congyan
Published: February 2024

Health state assessment is critical for mechanical equipment’s smooth and healthy operation. This paper proposes a novel approach for health state assessment based on acoustic signals during the process of machinery running. It consists of multi-domain feature (MF) extraction and comprehensive health indicator (CHI) construction. MF is extracted from various acoustic features, including time and frequency (TF) features, mel-frequency cepstral coefficients, and gammatone frequency cepstral coefficients. The stacked long short-term memory (LSTM) is used to extract the high-level features of the MF, which are then input to the downstream PCA to obtain the LSTM-PCA health indicator (LP-HI). Parallelly, the MF is fed into the self-organizing mapping (SOM) model to calculate the minimum quantization error (MQE) as SOM-MQE health indicator (SM-HI). These two indicators are fused using weighted fusion and nonlinear mapping to calculate CHI. The experimental results on air compressor dataset show a 25.8% reduction in evaluation error compared with SOTA results in this paper. The proposed nonlinear mapping function furthermore reduces fitting error on HI by 38.9%. These demonstrate the effectiveness and superiority of the proposed method in machinery health state assessment.
Preparation of multilayer samples for scanning thermal microscopy examination
Authors: Lees James , Corbetta Marco , Kleine-Boymann Matthias , Scheidemann Adi , Poon Siew Wai , Thompson Sarah M
Published: February 2024

Thin film multilayer materials are very important for a variety of key technologies such as hard drive storage. However, their multilayered nature means it can be difficult to examine them after production and determining properties of individual layers is harder still. Here, methods of preparing multilayer samples for examination using scanning thermal microscopy are compared, showing that both a combination of mechanical and ion beam polishing, and ion beam milling to form a crater produce suitable surfaces for scanning thermal microscopy examination. However, the larger exposed surfaces of the ion beam milled crater are the most promising for distinguishing between the layers and comparison of their thermal transport properties.
Enhanced LWIR response of InP/InAsP quantum discs-in-nanowire array photodetectors by photogating and ultra-thin ITO contacts
Authors: Jeddi Hossein , Adham Kristi , Zhao Yue , Witzigmann Bernd , Römer Friedhard , Bermeo Marie , Borgström Magnus T , Pettersson Håkan
Published: February 2024

Here we report on an experimental and theoretical investigation of the long-wavelength infrared (LWIR) photoresponse of photodetectors based on arrays of three million InP nanowires with axially embedded InAsP quantum discs. An ultra-thin top indium tin oxide contact combined with a novel photogating mechanism facilitates an improved LWIR normal incidence sensitivity in contrast to traditional planar quantum well photodetectors. The electronic structure of the quantum discs, including strain and defect-induced photogating effects, and optical transition matrix elements were calculated by an 8-band k·p simulation along with solving drift-diffusion equations to unravel the physics behind the generation of narrow linewidth intersubband signals observed from the quantum discs.
Suppressing HIFU interference in ultrasound images using 1D U-Net-based neural networks
Authors: Yang Kun , Li Qiang , Liu Hengxin , Zeng Qingxuan , Cai Dejia , Xu Jiahong , Zhou Yingying , Tsui Po-Hsiang , Zhou Xiaowei
Published: February 2024

Objective. One big challenge with high-intensity focused ultrasound (HIFU) is that the intense acoustic interference generated by HIFU irradiation overwhelms the B-mode monitoring images, compromising monitoring effectiveness. This study aims to overcome this problem using a one-dimensional (1D) deep convolutional neural network. Approach. U-Net-based networks have been proven to be effective in image reconstruction and denoising, and the two-dimensional (2D) U-Net has already been investigated for suppressing HIFU interference in ultrasound monitoring images. In this study, we propose that the one-dimensional (1D) convolution in U-Net-based networks is more suitable for removing HIFU artifacts and can better recover the contaminated B-mode images compared to 2D convolution. Ex vivo and in
vivo HIFU experiments were performed on a clinically equivalent ultrasound-guided HIFU platform to collect image data, and the 1D convolution in U-Net, Attention U-Net, U-Net++, and FUS-Net was applied to verify our proposal. Main results. All 1D U-Net-based networks were more effective in suppressing HIFU interference than their 2D counterparts, with over 30% improvement in terms of structural similarity (SSIM) to the uncontaminated B-mode images. Additionally, 1D U-Nets trained using ex vivo datasets demonstrated better generalization performance in in
vivo experiments. Significance. These findings indicate that the utilization of 1D convolution in U-Net-based networks offers great potential in addressing the challenges of monitoring in ultrasound-guided HIFU systems.