bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of streamer groups and radical generation in high-voltage multiple-pulse-induced nonthermal plasma
Authors: Shimada T. , Yamasaki H. , Okubo M.
Published: October 2023

Nonthermal plasmas (NTPs) induced by atmospheric nanosecond multiple-pulse corona discharge have been studied to control pollution generated by combustors, such as boilers, incinerators, and diesel engines. In high-speed short-width high-voltage pulsed corona discharge-induced plasmas, the chemical reactions that occur between multiple pulses and the characteristics of the electron density (denoted by ne) and ozone during the second pulse have not been fully clarified. In this study, we perform quasi-two-dimensional numerical analysis of nonequilibrium NTP induced by a nanosecond positive pulsed corona discharge. The continuum fluid equations for a two-temperature nonequilibrium NTP are used as governing equations. A total of 197 gas phase reactions for 25 chemical species and 21 surface reactions on the inner glass wall surface are considered in an air plasma under atmospheric pressure. We simulate streamer group behavior up to the second pulse and found that ne and the length of streamers change due to chemical reactions between pulses. In addition, we successfully simulated the phenomena of ne reduction and streamer suppression that occur primarily during the second pulse. This is caused by the decrease in potential gradient due to the space and dielectric surface charge build-up. Furthermore, it is confirmed that the ozone formation reaction mainly occurs between pulses. This simulation enables predictions of phenomena in nanosecond positive multiple-pulse plasma systems.
Spatially homogeneous teleparallel gravity: Bianchi I
Authors: Coley A. A. , van den Hoogen R. J.
Published: October 2023

Using a recently developed algorithm that chooses preferred coordinates and a preferred co-frame, we will determine the completely general Bianchi type I teleparallel geometry. In using this algorithm, any remaining gauge freedom is allocated to the choice of spin connection. We then solve the symmetry constraints placed on the spin connection to derive a general class of Bianchi type I teleparallel geometries. We find that this general class of Bianchi type I teleparallel geometries breaks naturally into two sub-classes. We then illustrate some simple power-law solutions in F(T) teleparallel gravity for each case to illustrate the differences.
The effect of scattering instability induced by high intensity seed on backward Raman amplification
Authors: Li Jiajun , Wang Xianzhi , Wang Zhaohua , Zhang Xu , Li Jiawen , Wei Zhiyi
Published: October 2023

Backward Raman amplification (BRA) in plasma has become one of the most promising techniques for further promoting light intensity. In this work, BRA in plasma is simulated using one-dimensional particle-in-cell code with different seed intensity, showing that higher seed intensity (in the range of 2×1011–2×1015 W/cm2) will increase energy conversion efficiency with pump pulse of fixed intensity (2×1014 W/cm2), which is pre-depleted by spontaneous Raman scattering. We find that the scattering instability of amplified seed pulse is enhanced and the plasma wave fluctuation level is promoted with seed intensity at 2×1016 W/cm2 because the local plasma density changes in the pump scattering depletion region. In the simulations, we also found that the enhanced Raman scattering and secondary Raman scattering of amplified seed pulse causes a rapid energy consumption and earlier saturation of the amplification, which significantly affects the temporal shape of the amplified seed pulse to form a double peak shape. In addition, we explore the evolution of the energy and the pulse duration of the double peaks in detail and reveal the law of pulse energy growth with different pulse durations in a Raman amplifier.
Impact of density stratification and azimuthal velocity on the growth of coherent structures in a convectively unstable swirl flame
Authors: Zhang Junhua , Hui Xin , An Qiang , Wang Zijian
Published: October 2023

Large-scale coherent structures resulting from hydrodynamic instabilities can interact with turbulent swirl flames and lead to combustion instabilities. The present work investigates the impact of density stratification and azimuthal velocity on the growth of coherent structures in a convectively unstable swirl flame. Flame structure and flow field are measured by simultaneous hydroxyl planar laser-induced fluorescence and stereoscopic particle image velocimetry (S-PIV) at a repetition rate of 10 kHz and are analyzed by using the spectral proper orthogonal decomposition (SPOD) and spatial linear stability analysis (LSA). The SPOD reveals that the dominant symmetric and anti-symmetric modes are within the frequency range from 156 to 585 Hz, accounting for more than 25% of the turbulent kinetic energy. The spatial growths of these coherent structures are quantified by the LSA that predicts large growth rates near the nozzle exit with the corresponding frequency band matching well with the SPOD analysis. The LSA results show that both density stratification and azimuthal velocity have little effect on the instability frequencies of the most spatially unstable modes. However, the flame-induced density stratification suppresses the growth of the coherent structures by altering the pressure gradient and viscous diffusion, whereas the azimuthal velocity promotes flow instabilities through the changes in convection and production of the coherent perturbations. The results also suggest that the conventional PIV technique with two-component velocity measurement is inadequate for linear modeling of coherent structures, and the density stratification should also be taken into account in convectively unstable swirl flames.
Deep learning dynamical latencies for the analysis and reduction of combustion chemistry kinetics
Authors: Castellanos Luisa , S. M. Freitas Rodolfo , Parente Alessandro , Contino Francesco
Published: October 2023

The modeling of chemical kinetics holds many challenges, as well as a necessity for more efficient modeling techniques, together with dimensionality reduction techniques. This work studies the application of time-lag auto-encoders for the analysis of combustion chemistry kinetics. Such a technique allows a better reconstruction of the thermochemical temporal advancement in relation to traditional reduction techniques (principal component analysis) while applying a potential denoising operation. Moreover, the reduced manifolds or latencies are provided with physical meaning, which further analysis gives insight into key chemical reactions and interactions between chemical species, allowing for a deeper understanding of the chemical mechanism itself.
Liquid distribution after head-on separation of two colliding immiscible liquid droplets
Authors: Potyka Johanna , Schulte Kathrin , Planchette Carole
Published: October 2023

Equally sized droplets made of the same liquid are known to either bounce, coalesce, or separate under collision. Comparable outcomes are observed for immiscible liquids with bouncing, encapsulation instead of coalescence, and separation with two or more daughter droplets. While the transitions between these regimes have been described, the liquid distribution arising from separation remains poorly studied, especially in the case of head-on collisions, for which it cannot be predicted. This distribution can be of three types: either two encapsulated droplets form (single reflex separation), or a single encapsulated droplet plus a droplet made solely of the encapsulating liquid emerge, the latter being found either on the impact side (reflexive separation) or opposite to it (crossing separation). In this paper, a large number of experimental and simulation data covering collisions with partial and total wetting conditions and Weber and Reynolds numbers in the ranges of 2–720 and 66–1100, respectively, is analyzed. The conditions leading to the three liquid distributions are identified and described based on the decomposition of the collision in two phases: (i) radial extension of the compound droplet into a lamella and (ii) its relaxation into an elongated cylindrical droplet. In accordance with these two phases, two dimensionless parameters, Λ=ρi/ρoWei−1/2 and N=νo/νi σo/σio, are derived, which are built on the collision parameters and liquid properties of the encapsulated inner droplet (i) and the outer droplet (o) only. The combination of these two parameters predicts the type of liquid distribution in very good agreement with both experimental and numerical results.
Inferring free-energy barriers and kinetic rates from molecular dynamics via underdamped Langevin models
Authors: Girardier David Daniel , Vroylandt Hadrien , Bonella Sara , Pietrucci Fabio
Published: October 2023

Rare events include many of the most interesting transformation processes in condensed matter, from phase transitions to biomolecular conformational changes to chemical reactions. Access to the corresponding mechanisms, free-energy landscapes and kinetic rates can in principle be obtained by different techniques after projecting the high-dimensional atomic dynamics on one (or a few) collective variable. Even though it is well-known that the projected dynamics approximately follows – in a statistical sense – the generalized, underdamped or overdamped Langevin equations (depending on the time resolution), to date it is nontrivial to parameterize such equations starting from a limited, practically accessible amount of non-ergodic trajectories. In this work we focus on Markovian, underdamped Langevin equations, that arise naturally when considering, e.g., numerous water-solution processes at sub-picosecond resolution. After contrasting the advantages and pitfalls of different numerical approaches, we present an efficient parametrization strategy based on a limited set of molecular dynamics data, including equilibrium trajectories confined to minima and few hundreds transition path sampling-like trajectories. Employing velocity autocorrelation or memory kernel information for learning the friction and likelihood maximization for learning the free-energy landscape, we demonstrate the possibility to reconstruct accurate barriers and rates both for a benchmark system and for the interaction of carbon nanoparticles in water.
Transition to turbulence in the wake of dandelion-like spoke disk
Authors: Dong Yangyang , Ni Yuyang , Hu Kexin , Zhang Tongle , Zhang Zijian , Wang Yongbin
Published: October 2023

In order to solve the inevitable instability problem of dandelion-like unpowered aircraft, transient simulations are carried out for the transition to turbulence of the wake from stable to unstable stage under different Reynolds numbers, and the vortex mode characteristics presented by the vortex structure as the Reynolds number increases are identified. Furthermore, by monitoring the velocity and lift and drag coefficients at different positions in dandelion flow field, the spectral characteristics of flow velocity and aerodynamic coefficients in the turbulent phase triggered by extreme aerodynamic environment are revealed. Compared with solid disk, it is found that the bandgap structure is more conducive to expanding the stable flight threshold of the dandelion-like aircraft, that is, the canopy configuration has weakening effect on airflow fluctuations. In addition, an evaluation method for unsteady boundary Reynolds number and load capacity of a dandelion-like aircraft is presented. The proposed method aims to plan a reasonable number of filaments (or porosity) for further designing dandelion-like aircraft with flight stability and high load capacity under aerodynamic conditions at different Reynolds numbers.
Ultrafast spectral diffusion of GaN defect single photon emitters
Authors: Geng Yifei , Nomoto Kazuki
Published: October 2023

Defect-based single photon emitters play an important role in quantum information technologies. Quantum emitters in technologically mature direct wide bandgap semiconductors, such as nitrides, are attractive for on-chip photonic integration. GaN has recently been reported to host bright and photostable defect single photon emitters in the 600–700 nm wavelength range. Spectral diffusion caused by local electric field fluctuation around the emitter limits the photon indistinguishability, which is a key requirement for quantum applications. In this work, we investigate the spectral diffusion properties of GaN defect emitters integrated with a solid immersion lens, employing both spectral domain and time domain techniques through spectroscopy and photon autocorrelation measurements at cryogenic temperature. Our results show that the GaN defect emitter at 10 K exhibits a Gaussian line shape with a linewidth of ∼1 meV while the spectral diffusion characteristic time falls within the range of a few hundred nanoseconds to a few microseconds. We study the dependency of the spectral diffusion rate and Gaussian linewidth on the excitation laser power. Our work provides insight into the ultrafast spectral diffusion in GaN defect-based single photon emitter systems and contributes toward harnessing the potential of these emitters for applications, especially for indistinguishable single photon generation.
An Eulerian based geometry conforming grid-block dynamic mesh refinement for the lattice Boltzmann method
Authors: Ahmed Farhanuddin , Gupta Amit , Arora Nipun
Published: October 2023

An algorithm for a three-dimensional fine-grid block encompassing a moving solid body using a multi-relaxation time model of the lattice Boltzmann method is proposed and developed. In this numerical framework, a geometry-conforming fine block shifts a coarse lattice unit as the object translates by same amount. The effective utilization of higher-order spatial interpolation has been demonstrated in place of the commonly used low-order temporal interpolation in traditional grid refinement techniques within the lattice Boltzmann method. The successful application of this method has been showcased through three distinct cases: the settling of a solid sphere in a fluid tank under the influence of gravity, hovering motion of an elliptic airfoil, and the “clap and fling” motion of an insect wing. In this regard, various interpolation schemes based on the location of nodes in the overlapping zones of fine and coarse block are discussed. In addition, two cases were evaluated, case 1 where distributions are interpolated and case 2 where macroscopic variables are directly interpolated. It was observed that both interpolations gave same computational accuracy for low Reynolds number [∼O(102)]. However, as Re is increased [∼O(103)], direct interpolation of macroscopic variables proved erroneous and resulted in a large deviation in fluid forces and is not recommended. The geometry-conforming dynamic mesh refinement results in a substantial decrease in computation time, approximately 90%, along with a memory reduction of about 80% compared to the fully refined counterpart.
Analysis of flow characteristics and cooling performance of a novel impingement/effusion structure with bypass hollow holes
Authors: Xu Zhi-peng , Zhu Hui-ren , Liu Cun-liang , Li Xin-lei
Published: October 2023

As a promising cooling technique, the double-wall cooling structure has been integrated into the design of advanced aeroengine high-temperature components. However, its widespread application in configurations with low pressure ratios between secondary flow and the main flow is hindered due to significant internal flow resistance. To address this issue, a novel low-resistance hollow pillar double-wall structure (NHDW) is developed. This study conducts conjugated heat transfer numerical simulations of NHDW and the traditional solid pillar double-wall structure (TSDW) for comparative analysis. Flow characteristics are examined to understand the sources of internal flow resistance and the coupling mechanism between internal and external heat transfer. The results demonstrate that the NHDW exhibits substantially lower flow resistance than the TSDW, with the total pressure loss dropping to approximately 1/3 of the corresponding TSDW under hole inclination angles of 30°, 60°, and 90°. The reduced internal flow resistance of the NHDW is attributed to the parallel bypass flow within the hollow pillar. Moreover, the overall cooling effectiveness (ϕ) of NHDW is enhanced by 9.2%–16.9% for different inclination angles at a blowing ratio of M = 1.0. Additionally, the interaction vortex structure on the mainstream side surface of the NHDW significantly improves the external cooling effectiveness, contributing to the overall enhancement of the cooling performance. Furthermore, a one-dimensional thermal resistance analysis method is introduced to distinguish the contributions of internal cooling and external film cooling. This analysis highlights the importance of external cooling enhancements in the novel structure.
Parametric instability in propagating flames and the impact of hydrogen enrichment on the onset of secondary instability
Authors: Jun Daeyoung , Lee Bok Jik
Published: October 2023

A self-excited acoustic instability of laminar premixed flames propagating in an open-ended tube with a length of 700 mm and a radius of 10 mm was simulated by solving the reacting unsteady compressible Navier–Stokes equations, to understand the way of massive acoustic generation and its onset behaviors. Four fuel–air mixtures with an equivalence ratio of 1.2 were considered, namely, methane–air and methane–hydrogen–air mixtures, to identify the role of hydrogen in rich methane–air mixture. Parametric instability, which generated huge acoustic disturbance and violent flame pulsations, was observed only for a particular methane–hydrogen–air mixture with RH = 0.2, consistent with previously reported experimental observations. For the investigation of the reinforcement mechanism of acoustic instability under parametric instability, the flame surface area modulation was examined. It was found that violent subharmonic flame front pulsations could strongly modulate the flame surface area in the fundamental mode, resulting in a fluctuating heat release rate and increased thermoacoustic coupling. When hydrogen addition was small, attaining a higher level of primary instability, which is the precursor of the parametric instability, was more dominant than increasing the threshold level for the onset of the parametric instability. With larger hydrogen addition, the increase in the threshold level was more dominant than attaining a higher level of the primary instability. In particular, as the flame propagation time decreased, the level of the primary instability was saturated in larger hydrogen addition. This study elucidates the mechanism for the acoustic generation of propagating flames under the parametric instability, and the effects of hydrogen enrichment within rich methane–air mixtures.
Weakening the spin–orbital coupling for band convergence
Authors: Zhou Yun , Chen Junqi , Zhou Zizhen , Zhou Xiaoyuan
Published: October 2023

Band convergence is a favorable strategy that is utilized to improve the thermoelectric performance in experiment, whereas a theoretical guidance for this purposive design is rare. With high-level first-principles treatment of electronic and transport properties in the emerging ABX (A = Ca, Sr, Ba; B = Cu, Ag; X = P, As, Sb) Zintl systems, a principled scheme via weakening the spin–orbital coupling is proposed based on symmetry and orbital analysis to promote the band convergence. This given rule is numerically confirmed in BaAgX alloys. Despite the intensified intervalley electron–phonon scattering, the alloying of BaAgP in BaAgSb prominently triggers the band convergence and contributes to much larger density of state effective mass, which eventually results in a ∼40% improvement in zT values. This work offers an applicable principle for designing band convergence, which also broads the compositions of thermoelectrics to light and earth-abundant elements.
Rayleigh–Bénard instability in a horizontal porous layer with anomalous diffusion
Authors: Barletta A.
Published: October 2023

The analysis of the Rayleigh–Bénard instability due to the mass diffusion in a fluid-saturated horizontal porous layer is reconsidered. The standard diffusion theory based on the variance of the molecular position growing linearly in time is generalized to anomalous diffusion, where the variance is modeled as a power-law function of time. A model of anomalous diffusion based on a time-dependent mass diffusion coefficient is adopted, together with Darcy's law, for momentum transfer, and the Boussinesq approximation, for the description of the buoyant flow. A linear stability analysis is carried out for a basic state where the solute has a potentially unstable concentration distribution varying linearly in the vertical direction, and the fluid is at rest. It is shown that any, even slight, departure from the standard diffusion process has a dramatic effect on the onset conditions of the instability. This circumstance reveals a strong sensitivity to the anomalous diffusion index. It is shown that subdiffusion yields instability for every positive mass diffusion Rayleigh number, while superdiffusion brings stabilization no matter how large is the Rayleigh number. A discussion of the linear stability analysis based on the Galilei-variant fractional-derivative model of subdiffusion is eventually carried out.
Developing Loop Mediated Isothermal Amplification (LAMP) assays for rapid, presumptive DNA detection of an invasive reptile (Boa constrictor)
Authors: Deliveyne Nathan , Austin Jeremy J. , Cassey Phillip
Published: October 2023

Context Wildlife trade is a prominent pathway for invasive species introductions into novel environments. Deliberate or accidental release of exotic pets can result in the establishment of alien populations, with damaging impacts for native species and environmental assets. This process is well documented for reptiles globally and is of considerable biosecurity concern in Australia. Boa constrictor is one species at high risk of establishment in Australia, and has insufficient biosecurity detection and post-border control capacity. Aims We aimed to develop rapid DNA-based presumptive testing capacity for detecting B. constrictor, with appropriate sensitivity and specificity to operate in a trace DNA biosecurity context. Methods Loop Mediated Isothermal Amplification (LAMP) is an emerging biosecurity tool that provides highly specific, sensitive, low-resource methods for detection of trace DNA in the absence of physical evidence. We developed colourimetric and fluorescent LAMP assays targeting the mitochondrial DNA control region of B. constrictor. We tested and validated these assays against synthetic DNA fragments, as well as DNA extracted from: (1) vouchered museum B. constrictor tissue; (2) shed B. constrictor skin samples; (3) a range of non-target species to test specificity; and (4) trace DNA recovered from glass tanks post B. constrictor presence. Key results We successfully detected synthetic target DNA down to 1 fg and genomic B. constrictor DNA from tissue and shed skins down to <10 pg in under 30 minutes with our fluorescence-based LAMP assay. Additionally, we were able to detect B. constrictor trace DNA following 24 h of presence utilising a traditional laboratory-based DNA extraction method (approximately 180 min) and a rapid lysis step (approximately 8 min). Conclusions Both colourimetric and fluorescent assays show promise for the specific detection of B. constrictor in biosecurity contexts, including post-border enforcement and compliance checks in the domestic illicit wildlife trade. Implications Our findings greatly strengthen the ongoing development of biosecurity tools for trace DNA detection of commonly traded and trafficked species (i.e. reptiles) in wildlife enforcement contexts, advancing both preparedness and surveillance.
Directional electronic tuning of Ni nanoparticles by interfacial oxygen bridging of support for catalyzing alkaline hydrogen oxidation
Authors: Sun Hongming , Li Cha , Yang Le , Han Yixuan , Yu Xueying , Li Cheng-Peng , Zhang Zhihong , Yan Zhenhua , Cheng Fangyi , Du Miao
Published: October 2023

Metallic nickel (Ni) is a promising candidate to substitute Pt-based catalysts for hydrogen oxidation reaction (HOR), but huge challenges still exist in precise modulation of the electronic structure to boost the electrocatalytic performances. Herein, we present the use of single-layer Ti
3
C
2
T
x
MXene to deliberately tailor the electronic structure of Ni nanoparticles via interfacial oxygen bridges, which affords Ni/Ti
3
C
2
T
x
electrocatalyst with exceptional performances for HOR in an alkaline medium. Remarkably, it shows a high kinetic current of 16.39 mA cm
disk
–2
at the overpotential of 50 mV for HOR [78 and 2.7 times higher than that of metallic Ni and Pt/C (20%), respectively], also with good durability and CO antipoisoning ability (1,000 ppm) that are not available for conventional Pt/C (20%) catalyst. The ultrahigh conductivity of single-layer Ti
3
C
2
T
x
provides fast transmission of electrons for Ni nanoparticles, of which the uniform and small sizes endow them with high-density active sites. Further, the terminated -O/-OH functional groups on Ti
3
C
2
T
x
directionally capture electrons from Ni nanoparticles via interfacial Ni–O bridges, leading to obvious electronic polarization. This could enhance the Ni
ds
–O
2p
interaction and weaken Ni
ds
–H
1s
interaction of Ni sites in Ni/Ti
3
C
2
T
x
enabling a suitable H-/OH-binding energy and thus enhancing the HOR activity.
Cytosolic iron–sulfur protein assembly system identifies clients by a C-terminal tripeptide
Authors: Marquez Melissa D. , Greth Carina , Buzuk Anastasiya , Liu Yaxi , Blinn Catharina M. , Beller Simone , Leiskau Laura , Hushka Anthony , Wu Kassandra , Nur Kübra , Netz Daili J. A. , Perlstein Deborah L. , Pierik Antonio J.
Published: October 2023

The eukaryotic cytosolic Fe–S protein assembly (CIA) machinery inserts iron–sulfur (Fe–S) clusters into cytosolic and nuclear proteins. In the final maturation step, the Fe–S cluster is transferred to the apo-proteins by the CIA-targeting complex (CTC). However, the molecular recognition determinants of client proteins are unknown. We show that a conserved [LIM]-[DES]-[WF]-COO
–
tripeptide is present at the C-terminus of more than a quarter of clients or their adaptors. When present, this targeting complex recognition (TCR) motif is necessary and sufficient for binding to the CTC in vitro and for directing Fe–S cluster delivery in vivo. Remarkably, fusion of this TCR signal enables engineering of cluster maturation on a nonnative protein via recruitment of the CIA machinery. Our study advances our understanding of Fe–S protein maturation and paves the way for bioengineering novel pathways containing Fe–S enzymes.
DNA language models are powerful predictors of genome-wide variant effects
Authors: Benegas Gonzalo , Batra Sanjit Singh , Song Yun S.
Published: October 2023

The expanding catalog of genome-wide association studies (GWAS) provides biological insights across a variety of species, but identifying the causal variants behind these associations remains a significant challenge. Experimental validation is both labor-intensive and costly, highlighting the need for accurate, scalable computational methods to predict the effects of genetic variants across the entire genome. Inspired by recent progress in natural language processing, unsupervised pretraining on large protein sequence databases has proven successful in extracting complex information related to proteins. These models showcase their ability to learn variant effects in coding regions using an unsupervised approach. Expanding on this idea, we here introduce the Genomic Pre-trained Network (GPN), a model designed to learn genome-wide variant effects through unsupervised pretraining on genomic DNA sequences. Our model also successfully learns gene structure and DNA motifs without any supervision. To demonstrate its utility, we train GPN on unaligned reference genomes ofArabidopsis thalianaand seven related species within the Brassicales order and evaluate its ability to predict the functional impact of genetic variants inA. thalianaby utilizing allele frequencies from the 1001 Genomes Project and a comprehensive database of GWAS. Notably, GPN outperforms predictors based on popular conservation scores such as phyloP and phastCons. Our predictions forA. thalianacan be visualized as sequence logos in the UCSC Genome Browser (https://genome.ucsc.edu/s/gbenegas/gpn-arabidopsis). We provide code (https://github.com/songlab-cal/gpn) to train GPN for any given species using its DNA sequence alone, enabling unsupervised prediction of variant effects across the entire genome.
Advancing Sino-Philippine linguistics and sociolinguistics using the Lannang Corpus (LanCorp)
Authors: Gonzales Wilkinson Daniel Wong
Published: October 2023

This paper introduces the Lannang Corpus (LanCorp), a public 375,000-word collection of raw and transcribed
recordings of Lannang languages spoken in metropolitan Manila, which have been annotated with part-of-speech tags and linked to 40
types of sociolinguistic metadata. It begins by providing an overview of the LanCorp (e.g. design, formats, accessibility). Then,
it goes on to show various examples of how the corpus can be used for variationist sociolinguistic research, using Lánnang-uè data
as a case study. The findings from the exploratory studies indicate that Lannang languages are influenced by sociolinguistic
factors, demonstrating the intricate nature of the Sino-Philippine sociolinguistic ecology. Due to its large size, sociolinguistic
metadata, and various formats, LanCorp can be used to study Lannang languages in general and how they are used by specific social
groups. It enables scholars to investigate multilingual interactions in a wide range of sociolinguistic factors, furthering the
field of Sino-Philippine (socio)linguistics.
Conceptual deviation in terminology translation
Authors: Li Biwei
Published: October 2023

Viewing the conceptual dynamicity of terminology as a major challenge in translation practices, this article proposes a framework for studying conceptual deviation in terminology translation. A case study based on a multilingual parallel corpus of journalistic translation is carried out to examine the conceptual deviation in Chinese and Spanish translations of several COVID-19-related terms in health communication via international news media. The results suggest that conceptual deviation occurs to varying degrees in translation and the Chinese translation conceptually deviates more from the source text than the Spanish translation does. Based on the premise that conceptual deviation may occur because of the sociocultural constraints on journalistic translation as an activity of cross-linguistic and -cultural health communication, the causes and impact of conceptual deviation in terminology translation are also discussed.
Cryo-EM reveals how the mastigoneme assembles and responds to environmental signal changes
Authors: Wang Yue , Yang Jun , Hu Fangheng , Yang Yuchen , Huang Kaiyao , Zhang Kai
Published: October 2023

Mastigonemes are thread-like structures adorning the flagella of protists. In Chlamydomonas reinhardtii, filamentous mastigonemes find their roots in the flagella’s distal region, associated with the channel protein PKD2, implying their potential contribution to external signal sensing and flagellar motility control. Here, we present the single-particle cryo-electron microscopy structure of the mastigoneme at 3.4 Å. The filament unit, MST1, consists of nine immunoglobulin-like domains and six Sushi domains, trailed by an elastic polyproline-II helix. Our structure demonstrates that MST1 subunits are periodically assembled to form a centrosymmetric, non-polar filament. Intriguingly, numerous clustered disulfide bonds within a ladder-like spiral configuration underscore structural resilience. While defects in the mastigoneme structure did not noticeably affect general attributes of cell swimming, they did impact specific swimming properties, particularly under varied environmental conditions such as redox shifts and heightened viscosity. Our findings illuminate the potential role of mastigonemes in flagellar motility and suggest their involvement in diverse environmental responses.
Identifiability of equilibrium constants for receptors with two to five binding sites
Authors: Benndorf Klaus , Schulz Eckhard
Published: October 2023

Ligand-gated ion channels (LGICs) are regularly oligomers containing between two and five binding sites for ligands. Neither in homomeric nor heteromeric LGICs the activation process evoked by the ligand binding is fully understood. Here, we show on theoretical grounds that for LGICs with two to five binding sites, the cooperativity upon channel activation can be determined in considerable detail. The main requirements for our strategy are a defined number of binding sites in a channel, which can be achieved by concatenation, a systematic mutation of all binding sites and a global fit of all concentration–activation relationships (CARs) with corresponding intimately coupled Markovian state models. We take advantage of translating these state models to cubes with dimensions 2, 3, 4, and 5. We show that the maximum possible number of CARs for these LGICs specify all 7, 13, 23, and 41 independent model parameters, respectively, which directly provide all equilibrium constants within the respective schemes. Moreover, a fit that uses stochastically varied scaled unitary start vectors enables the determination of all parameters, without any bias imposed by specific start vectors. A comparison of the outcome of the analyses for the models with 2 to 5 binding sites showed that the identifiability of the parameters is best for a case with 5 binding sites and 41 parameters. Our strategy can be used to analyze experimental data of other LGICs and may be applicable to voltage-gated ion channels and metabotropic receptors.
Giant 2D Skyrmion Topological Hall Effect with Ultrawide Temperature Window and Low-Current Manipulation in 2D Room-Temperature Ferromagnetic Crystals
Authors: Zhang 张 Gaojie 高节 , Luo 罗 Qingyuan 清源 , Wen 文 Xiaokun 晓琨 , Wu 武 Hao 浩 , Yang 杨 Li 丽 , Jin 靳 Wen 雯 , Li 李 Luji 路吉 , Zhang 张 Jia 佳 , Zhang 张 Wenfeng 文峰 , Shu 舒 Haibo 海波 , Chang 常 Haixin 海欣
Published: October 2023

The discovery and manipulation of topological Hall effect (THE), an abnormal magnetoelectric response mostly related to the Dzyaloshinskii–Moriya interaction (DMI), are promising for next-generation spintronic devices based on topological spin textures such as magnetic skyrmions. However, most skyrmions and THE are stabilized in a narrow temperature window either below or over room temperature with high critical current manipulation. It is still elusive and challenging to achieve large THE with both wide temperature window till room temperature and low critical current manipulation. Here, using controllable, naturally oxidized sub-20 and sub-10 nm 2D van der Waals room-temperature ferromagnetic Fe3GaTe2−x
crystals, we report robust 2D skyrmion THE with ultrawide temperature window ranging in three orders of magnitude from 2 to 300 K, in combination with giant THE of ∼ 5.4 μΩ⋅cm at 10 K and ∼ 0.15 μΩ⋅cm at 300 K, which is 1–3 orders of magnitude larger than that of all known room-temperature 2D skyrmion systems. Moreover, room-temperature current-controlled THE is also realized with a low critical current density of ∼ 6.2 × 105 A⋅cm−2. First-principles calculations unveil natural oxidation-induced highly enhanced 2D interfacial DMI reasonable for robust giant THE. This work paves the way to room-temperature electrically controlled 2D THE-based practical spintronic devices.
Modifying the Electron Dynamics in High-Order Harmonic Generation via a Two-Color Laser Field
Authors: Zhang 张 Cai-Ping 彩萍 , Miao 苗 Xiang-Yang 向阳
Published: October 2023

We investigate the harmonic emission from bichromatic periodic potential by numerically solving the time-dependent Schrödinger equation in the velocity gauge. The results show that the harmonic minimum is sensitive to the wavelength. Moreover, distinct crystal momentum states contribute differently to harmonic generation. In momentum space, the electron dynamics reveal a close relationship between the spectral minimum and the electron distribution in higher conduction bands. Additionally, by introducing an ultraviolet pulse to the fundamental laser field, the suppression of the harmonic minimum occurs as a result of heightened electron populations in higher conduction bands. This work sheds light on the harmonic emission originating from a solid with a two-atom basis.
Unidirectional Negative Refraction at an Exceptional Point of Acoustic PT-Symmetric Systems
Authors: Liu 刘 Chen 宸 , Lan 蓝 Jun 君 , Gu 顾 Zhongming 仲明 , Zhu 祝 Jie 捷
Published: October 2023

We demonstrate a method to realize unidirectional negative refraction in an acoustic parity-time (PT)-symmetric system, which is composed of a pair of metasurfaces sandwiching an air gap. The pair of metasurfaces possesses loss and gain modulations. The unidirectional negative refraction, which is strictly limited to the case of incident wave imposing on the loss end of the metasurface, is demonstrated at the exception point (EP) in this PT-symmetric system, while the incidence from the other side leads to strong reflection. Based on rigorous calculations, we explicitly show the underlying mechanism of this model to achieve unidirectional wave scatterings around the EP in the parametric space. In addition, the perfect imaging of a point source in the three-dimensional space, as a signature of negative refraction, is simulated to provide a verification of our work. We envision that this work may sharpen the understanding of PT-symmetric structures and inspire more acoustic functional devices.
Interatomic Coulombic electron capture: the story so far
Authors: Bande Annika , Fasshauer Elke , Molle Axel , Peláez Daniel , Pont Federico M , Sisourat Nicolas
Published: October 2023

Inter-particle Coulombic electron capture (ICEC) is an environment-enabled electron capture process by means of which a free electron can be efficiently attached to a system (e.g. ion, atom, molecule, or quantum dot (QD)). The excess electron attachment energy is simultaneously transferred to a neighbouring system which concomitantly undergoes ionization (or excitation). ICEC has been theoretically predicted in van-der-Waals and in hydrogen-bonded systems as well as in QD arrays. The theoretical approaches employed in these works range from analytical models to electronic structure and (quantum) dynamical calculations. In this article, we provide a comprehensive review of the main theoretical approaches that have been developed and employed to investigate ICEC and summarize the main conclusions learned from these works. Since knowledge on ICEC is still in its early stage, we conclude this review with our own views and proposals on the future perspectives for the research in ICEC.
The impact of contact and contactless interactions between the meta-atoms on terahertz bound states in the continuum
Authors: Xue Yonghui , Zhao Zhenyu , Liu Peiliang , Qin Hua , Ako Rajour Tanyi , Sriram Sharath
Published: October 2023

The excitation and manipulation of symmetry-protected bound states in the continuum (SP-BIC) is significantly valuable for metasurface-based biosensors. The interactions between adjacent meta-atoms determine the fundamental properties of SP-BIC; however, this topic has not been profoundly explored. In this work, we experimentally and numerically investigate the effects of contactless and contact interactions between adjacent dual-gap split-ring resonators (DSRRs) on the SP-BIC. We demonstrate that there is only one SP-BIC at 0.9 THz when the incident radiation polarization is parallel to the gap in both contactless and contact coupling conditions. When the polarization is vertical to the gap, the individual SP-BIC shifts the frequency to 0.8 THz under contactless coupling. Under contact coupling, the SP-BIC degrades to be an electromagnetically induced transparency (EIT) windows at 0.8 THz. We calculated a 3.6 ps group delay of slow light for EIT. Numerical simulations indicate that the combination of one magnetic dipole (MD) in the inner arm and another electric dipole in the outer arm of DSRR results in quasi-BIC at 0.9 THz and 0.8 THz under contactless coupling. Under contact coupling conditions, the formation of quasi-BIC at 0.9 THz is similar to contactless coupling. However, two MDs of opposite polarity results in the EIT windows at 0.8 THz. Our results reveal excitation and manipulation of terahertz SP-BIC via contactless and contact coupling, which is significant for the innovation of terahertz biosensors.
Stop comparing resummation methods
Authors: Löfgren Johan
Published: October 2023

I argue that the consistency of any resummation method can be established if the method follows a power counting derived from a hierarchy of scales. I.e. whether it encodes a top-down effective field theory. This resolves much confusion over which resummation method to use once an approximation scheme is settled on. And if no hierarchy of scales exists, you should be wary about resumming. I give evidence from the study of phase transitions in thermal field theory, where adopting a consistent power-counting scheme and performing a strict perturbative expansion dissolves many common problems of such studies: gauge dependence, strong renormalization scale dependence, the Goldstone boson catastrophe, IR divergences, imaginary potentials, mirages (illusory barriers), perturbative breakdown, and linear terms.
Constrained neutrino mass matrix and Majorana phases
Authors: Chakraborty Pralay , Dey Manash , Roy Subhankar
Published: October 2023

We endeavour to constrain the neutrino mass matrix on the phenomenological ground and procure model-independent textures by emphasizing on the simple linear relationships among the mass matrix elements. These simple textures predict the two Majorana phases. In this regard, two types of parametrization of neutrino mass matrix: general and exponential are employed. We obtain fifty-three predictive neutrino mass matrix textures, out of which twenty-eight are associated with the general parametrization, and the rest belong to the exponential one. Apart from Type-A/P textures, the rest deal with the prediction of a few other oscillation parameters as well. We try to realize the proposed textures in the light of A
4, Δ(27) and T
7 symmetry groups.
The minimal flavor structure of quarks and leptons
Authors: Zhang Ying
Published: October 2023

A flavor structure with minimal parameters is proposed to address the fermion mass hierarchy and flavor mixing for quarks and leptons. Yukawa interaction is reconstructed in a new basis to show a common flat structure for up-type quarks, down-type quarks, charged leptons, and Dirac neutrinos. A

SO
(
2

)

LR

f

flavor symmetry is found from the hierarchy masses of quarks and leptons, which dominated Cabibbo–Kobayashi–Maskawa (CKM) mixing for quarks and Pontecorvo–Maki–Nakagawa–Sakata mixing for leptons. It results that the minimal flavor structure successfully addresses flavor mixings of quarks and leptons even in the mass hierarchy limit, which means that mass hierarchy and flavor mixing are two independent questions. As a prediction, a sum rule on the mixing angles and CP violation phase (CPV) is suggested, which explains the smallness of s
13 as a natural result of the mass hierarchy. Generalizing the flat structure to quarks and leptons, a unified Yukawa interaction is also achieved for all fermions with only a single coupling.
Crossover from gapped-to-gapless Dirac surface states in magnetic topological insulator MnBi2Te4
Authors: Rastogi Gagan , Mohapatra Abhinab , Mishra Pramita , Mandal Shoubhik , Kulkarni Ruta , Ganesan R , Thamizhavel A , Anil Kumar P S
Published: October 2023

Intrinsic magnetic topological insulators (MTIs) host exotic topological phases such as quantized anomalous Hall insulating phase, arising due to the large magnetic exchange gap. However, the interplay of magnetism and topology in these systems in different temperature regimes remains elusive. In this work, we present the logarithmic temperature-dependence of conductivity for sub-100 nm thick exfoliated flakes of MTI MnBi2Te4 in the presence of out-of-plane magnetic fields and extracted the linear slope, κ. We observed a characteristic change,

Δ

κ

∼

−
0.5

in the low-temperature regime, indicating the gapped Dirac surface state according to Lu–Shen theory. We also report the recovery of topological properties in the system via the weak-antilocalization effect in the vicinity of antiferromagnetic to paramagnetic transition and in the paramagnetic regime. Hikami–Larkin–Nagaoka analysis suggested the presence of topological surface states. Therefore, our study helps in understanding how intrinsic magnetism masks topological properties in an MTI as long as magnetic ordering persists.
Edge state behavior in a Su–Schrieffer–Heeger like model with periodically modulated hopping
Authors: Kar Satyaki
Published: October 2023

Su–Schrieffer–Heeger (SSH) model is one of the simplest models to show topological end/edge states and the existence of Majorana fermions. Here we consider a SSH like model both in one and two dimensions where a nearest neighbor hopping features spatially periodic modulations. In the 1D chain, we witness appearance of new in-gap end states apart from a pair of Majorana zero modes (MZMs) when the hopping periodicity go beyond two lattice spacings. The pair of MZMs, that appear in the topological regime, characterize the end modes each existing in either end of the chain. These, however, crossover to both-end end modes for small hopping modulation strength in a finite chain. Contrarily in a 2D SSH model with symmetric hopping that we consider, both non-zero and zero energy topological states appear in a finite square lattice even with a simple staggered hopping, though the zero energy modes disappear in a ribbon configuration. Apart from edge modes, the 2D system also features corner modes as well as modes with satellite peaks distributed non-randomly within the lattice. In both the dimensions, an increase in the periodicity of hopping modulation causes the zero energy Majorana modes to become available for either sign of the modulation. But interestingly with different periodicity for hopping modulations in the two directions, the zero energy modes in a 2D model become rarer and does not appear for all strength and sign of the modulation.
Effective methods for monitoring internal contamination among workers handling radioactive materials in various fields
Authors: Yoon Seokwon , Kim Jae Seok , Yoo Jaeroyng , Cho Minsu
Published: October 2023

This study aimed to develop effective methods for monitoring internal contamination among workers handling radioactive materials in various fields. A total of 160 workers from nuclear power plants, medical institutions, military units, and educational/research institutions were included in the study. The monitoring methods included urinalysis and whole-body counting (WBC) using a mobile radio bioassay laboratory (MRL). Gamma-emitting radionuclides were monitored using the MRL WBC system, and a separate pretreatment procedure was used for tritium measurement in urine samples. Gross beta-screening was performed using a liquid scintillation counting system. The results were evaluated on the basis of the established screening criteria and compared with the dose limits. Additionally, tritium concentrations in the bodies of workers in the vicinity of a heavy-water reactor was analysed to assess the association between tritium concentration and occupation. The results showed a wide distribution of tritium concentrations. Workers involved in fuel and maintenance tasks demonstrated the maximum exposure. Workers in medical facilities showed low levels of internal contamination, which was primarily related to tasks involving radioactive isotopes. Military personnel involved in equipment repair showed significant tritium contamination due to damage during repairs. Workers in educational and research institutions in general had low levels of internal contamination.