bluuebunny/crossref_metadata_2025 huggingface dataset:
Cultural transmission among hunter-gatherers
Authors: Hewlett Barry S. , Boyette Adam H. , Lew-Levy Sheina , Gallois Sandrine , Dira Samuel Jilo
Published: November 2024

We examine from whom children learn in mobile hunter-gatherers, a way of life that characterized much of human history. Recent studies on the modes of transmission in hunter-gatherers are reviewed before presenting an analysis of five modes of transmission described by Cavalli-Sforza and Feldman [L. L. Cavalli-Sforza, M. W. Feldman, Cultural Transmission and Evolution: A Quantitative Approach (1981)] but not previously evaluated in hunter-gatherer research. We also present two modes of group transmission, conformist transmission, and concerted transmission, seldom mentioned in hunter-gatherer social learning research, and propose a unique mode of group transmission called cumulative transmission. The analysis of the additional modes of transmission indicated that cultural evolutionary signatures of vertical transmission, such as the conservation of cultural traits, have been underestimated because previous studies have seldom considered remote generations or distinguished intrafamilial from extrafamilial horizontal and oblique transmission. However, field data also indicate that hunter-gatherer children interacted with and learned from many nongenetically related individuals; about half of children’s and adolescents’ horizontal and oblique social learning came from nongenetically related individuals. Intimate living conditions of hunter-gatherers provide opportunities for group transmission, and ethnographic evidence presented demonstrates that at least three types of group transmission exist. All three forms of group transmission theoretically contribute to the conservation of culture, homogeneity of intracultural diversity, and high intercultural diversity. Analysis of additional modes of oblique and horizontal transmission and discussion of previous and unique modes of group transmission demonstrate the various mechanisms by which hunter-gatherer children learn and how cultures are conserved and contribute to cumulative culture.
High energetic cost of color change in octopuses
Authors: Sonner Sofie C. , Onthank Kirt L.
Published: November 2024

For many animals, color change is a critical adaptive mechanism believed to carry a substantial energetic cost. Yet, no study to date has directly measured the energy expenditure associated with this process. We examined the metabolic cost of color change in octopuses by measuring oxygen consumption in samples of excised octopus skin during periods of chromatophore expansion and contraction and then modeled metabolic demand over the whole octopus as a function of octopus mass. The metabolic demand of the fully activated chromatophore system is nearly as great as an octopus’s resting metabolic rate. This high metabolic cost carries ecological and evolutionary implications, including selective pressures in octopuses that may influence the adoption of nocturnal lifestyles, the use of dens, the reduction of the chromatophore system in deep-sea species, and metabolic trade-offs associated with foraging.
Metabolic scaling, energy allocation tradeoffs, and the evolution of humans’ unique metabolism
Authors: Yegian Andrew K. , Heymsfield Steven B. , Castillo Eric R. , Müller Manfred J. , Redman Leanne M. , Lieberman Daniel E.
Published: November 2024

All organisms use limited energy to grow, survive, and reproduce, necessitating energy allocation tradeoffs, but there is debate over how selection impacted metabolic budgets and tradeoffs in primates, including humans. Here, we develop a method to compare metabolic rates as quotients of observed relative to expected values for mammals corrected for size, body composition, environmental temperature, and phylogenetic relatedness. Contrary to previous analyses, these quotients reveal that nonhuman primates have total metabolic rates expected for similar-sized mammals in similar environments. In addition, data from several small-scale societies show that humans evolved exceptionally high resting, activity, and total metabolic rates apparently by overcoming tradeoffs between resting and active energy expenditures that constrain other primates. Enhanced metabolic rates help humans fuel expanded brains, faster reproductive rates, extended longevity, and high percentage of body fat.
Stabilizing selection in an identified multisensory neuron in blind cavefish
Authors: Hildebrandt Mercedes , Kotewitsch Mona , Kaupp Sabrina , Salomon Sophia , Schuster Stefan , Machnik Peter
Published: November 2024

The ability to follow the evolutionary trajectories of specific neuronal cell types has led to major insights into the evolution of the vertebrate brain. Here, we study how cave life in the Mexican tetra (
Astyanax mexicanus
) has affected an identified giant multisensory neuron, the Mauthner neuron (MN). Because this neuron is crucial in driving rapid escapes, the absence of predation risk in the cave forms predicts a massive reduction in this neuron. Moreover, the absence of functional eyes in the
A. mexicanus
Pachón form predicts an even stronger reduction in the cell’s large ventral dendrite that receives visual inputs in sighted fish species. We succeeded in recording in vivo from this neuron in the blind cavefish and two surface tetra (
A. mexicanus
and
Astyanax aeneus
), which offers unique chances to simultaneously study evolutionary changes in morphology and function in this giant neuron. In contrast to the predictions, we find that cave life, while sufficient to remove vision, has neither affected the cell's morphology nor its functional properties. This specifically includes the cell's ventral dendrite. Furthermore, cave life did not increase the variance in morphological or functional features. Rather, variability in surface and cave forms was the same, which suggests a complex stabilizing selection in this neuron and a continued role of its ventral dendrite. We found that adult cavefish are potent predators that readily attack smaller fish. So, one of the largely unknown stabilizing factors could be using the MN in such attacks and, in the young fish, escaping them.
Listening strategy instruction for EMI learners to understand teacher input in science classrooms
Authors: Fung Daniel
Published: November 2024

Listening strategies have mostly been investigated in contexts where learners listen to audio recordings. However,
a much more prevalent and indispensable listening task in the classroom is listening to teacher input, particularly in the English
Medium Instruction (EMI) classroom where the goal of learning is directed towards comprehension of content subject knowledge
(e.g., science, geography). Research has also shown that teacher talk dominates EMI classroom interaction, making it even more
important to understand how learners comprehend teacher input. However, little research has been conducted in this area, and even
less attention has been devoted to exploring how learners can learn to listen in this classroom context through strategy
instruction. This paper reports on a study that implemented a listening strategy instruction programme for a class of secondary
school EMI students. The study started with a needs analysis, followed by strategy instruction sessions, and lesson observations
and stimulated recall interviews. This paper presents data from two EMI students as focal participants and explores how they
improved their strategic behaviour when comprehending teacher input in the EMI classroom. Both students widened their strategic
repertoires, but the high achiever benefited more from the strategy instruction programme than the weaker student. This paper ends
with pedagogical implications, highlighting the importance of listening strategy instruction for EMI learners.
Self-regulation to develop autonomy in language teacher education
Authors: Ambinintsoa Dominique Vola , Castro Eduardo
Published: November 2024

This article reports on a two-phased research study on the promotion of learner autonomy conducted in a teaching
college in Madagascar. Phase one aimed to help English as a Foreign Language (EFL) pre-service teachers improve their writing and
simultaneously develop their self-regulated learning (SRL) skills through journal writing in a bespoke nine-week reflective
writing course. The course was designed with the belief that promoting learner autonomy necessarily involves reflection on the
learning process, goals, and outcomes of learning, and that successful SRL results in increased learner autonomy. In addition,
teachers who have experienced learner autonomy are more likely to promote it in their teaching. The collected data from the course
consisted of the participants’ journal entries related to each writing task and written reflections on the course, which were
submitted to thematic analysis. Phase two took place two years after phase one. Data collection for this phase consisted of Google
Form questions and email exchanges that were intended to investigate the long-term impact of the reflective writing course on the
pre-service teachers’ ways of learning and on their preparation for their teaching practice. To illustrate the impact of the two
phases in detail, this article focuses on two case studies. They were chosen because these two participants showed lack of
self-confidence and struggles with writing at the beginning of phase one, and yet, were able to develop their SRL skills, in
particular, their goal setting and self-evaluation. This paper provides a unique contribution to the field, since not much
research has investigated learner autonomy or SRL in education in Madagascar, and few studies have returned to participants after
some time to assess long-term impact.
Longitudinal interactions of L2 learners’ motivations and strategic behavior in strategies-based writing
instruction
Authors: Teng Lin Sophie , Wei Jia , Zhang Lawrence Jun
Published: November 2024

Strategic behavior for self-regulated learning (SRL) is crucial for academic success in L2 writing. Yet little is
known about how learners’ motivation-related factors develop as their strategic behavior progresses during classroom instruction
in L2 writing contexts. Informed by SRL theory, this longitudinal case study adopted multiple assessment approaches to explicating
the development trajectories of two Chinese L2 writers’ motivational factors relating to expectancy, value, and goal orientation
(i.e., self-efficacy, task value, and goal orientations) and strategic behavior in the classroom ecology of self-regulation
strategies-based instruction. Participants were one high-proficiency writer and one low-proficiency writer who were enrolled in
the self-regulation strategies-based writing course. They voluntarily participated in this study and completed semi-structured
interviews and reflective journals at the beginning (T1), the middle (T2), and the end of the instruction (T3). Field notes were
used to complement the primary data sources. The qualitative analyses revealed both students’ limited understanding of SRL
strategies at the initial stage. Their strategic behavior progressed with the social and metacognitive scaffolding at T2, but only
the high-proficiency writer sustained active engagement at T3. With different goal orientations and linguistic self-efficacy at
the initial stage, both students reported noticeable increases in their intrinsic goal orientation, task value, and self-efficacy
in classroom performance at T2 and T3. Their motivational states were also affected by linguistic proficiency, metacognitive
scaffolding, and social interactions during the instruction. This study is expected to provide insights into how L2 writers’ strategic behavior progresses with their changes in
motivations.
Adult migrants’ Norwegian language learning investment strategies in the workplace
Authors: Arum Nuranindia Endah
Published: November 2024

Learning the host country’s language(s) is a necessary step toward social and professional inclusion for migrants.
However, it is often regarded as a challenging task that depends heavily on the sociocultural context in which migrants are
situated. This study explores the Norwegian language learning strategies of highly educated Indonesians outside the classroom,
particularly in the workplace, in Norway. Following the social turn in second language learning research, the study aims to
investigate how social context influences migrants’ strategies for learning Norwegian. The data were collected through a
combination of qualitative methods consisting of sequential in-depth interviews, language diaries, and focus group discussions
with four focal participants, including both recently arrived and long-term migrants. Based on Darvin and Norton’s (2015) investment model, participants’ narratives of their reported language learning strategies
are analyzed in relation to language ideology, identity, and capital in their language learning experiences. The findings from this
study suggest that migrant learners’ ideal learning strategies are influenced by their language ideologies. However, different
contextual factors, such as work tasks and roles, have a considerable impact on their learning opportunities, and consequently, on
why and how they end up using certain learning strategies but not others. Migrants’ professional identities also play an important
role in their strategy choice and use. By analyzing migrant learners’ narratives, this study provides a nuanced and
learner-centered understanding of language learning strategies in the context of migration in the globalized world. This study
also contributes new insights into the use of learning strategies of languages other than English by adult migrant learners inside
and beyond the classroom.
On the uses and restrictions of postverbal markers kah, liáu, and tio̍h in Taiwanese
Authors: Lau Seng-hian
Published: November 2024

In Taiwanese, when a sentence or predicate follows a verb or an adjective, one of three distinct markers (kah, liáu, or tio̍h) usually occurs. Previous investigations have not provided a clear explanation of these markers. This poses difficulties in teaching Taiwanese as a second language and hinders analytical precision. Through a judgment survey conducted with nine proficient native consultants, this study comprehensively elucidates the usage of these three markers while distinctly delineating their similarities and differences. Firstly, the consultants’ responses substantiate the declining usage of V-liáu and V-tio̍h. Moreover, this study highlights the constraints associated with the types of predicates preceding these markers and how these markers are used. Furthermore, it points out that, unlike the consistent nature of resultatives in some languages, when used as a resultative, V-kah represents a strong resultative, V-liáu represents a weak resultative, and V-tio̍h exhibits both strong and weak aspects depending on the orientation involved (subject- vs. object-orientation). Additionally, this study presents one of the first to show that object-oriented constituents following these markers are subject to limitations based on their predicate types. Lastly, this study examines the ambiguous temporal implications associated with V-liáu and V-tio̍h in previous research.
Encoding complex speech acts via sentence final particles
Authors: Jin Jing
Published: November 2024

This paper examines the use of the sentence final particle tai (呔) in the Changsha dialect (Xiang Chinese). It is demonstrated that tai encodes complex speech acts: on the one hand, it expresses the speaker’s high degree of certainty about the truth value of the associated proposition p; on the other, it seeks the addressee’s confirmation, via an implicitly entailed biased question, of the truth value of p. In view of the discursive interplay between the speaker and the addressee expressed by tai, the present study adopts a syntax-pragmatics interface approach to the syntax of tai, decomposing the complex speech acts it conveys into three functional projections at the structural level. Two are related to the speaker’s and the addressee’s knowledge/belief in the utterance (i.e., GroundSpkrP and GroundAdrP) and one is responsible for the speaker’s call on the addressee to confirm (i.e., ResponseP). This study contributes to cross-linguistic investigations on the grammatical realization of complex speech acts, an area which remains in its infancy. Tai represents a new type of grammatical strategy for expressing complex speech acts, that is, to encode the speaker’s commitment and the addressee’s engagement via a single lexical element without any particular intonation pattern.
Special pronominal forms in Saaroa
Authors: Li Paul Jen-kuei
Published: November 2024

Saaroa has a special set of pronominal forms not found in most other Formosan languages, as first noted by Pan (2018). This study departs from his claims that these forms only function as plurals. In fact, extensive Saaroa texts collected by different linguists (Li 2023) at different periods of time indicate that they can be either singular or plural. The functions of both the special free and bound forms will be clarified. Above all, they are contrastive. The origin of the special forms in Saaroa is suggested as a diffusion from Kanakanavu, which has similar forms with similar functions recorded earlier and is geographically adjacent. That the first person plural forms may function as singular is found not only in a few other Formosan languages, but also in unrelated languages. This study has thus cross-linguistic evidence and implications for languages in general.
Circumstantial and tactic augmentation
Authors: Alishaei Zahra , Jalilifar Alireza , Don Alexanne
Published: November 2024

The present study attempts to unveil patterns in interactive information structure of clause enhancement that conventionalize the actual representation of circumstantial elements which add information about time, place, manner, means, and reason/cause through circumstantial augmentation, tactic augmentation, or connectives in method sections of research articles (RAs). The dataset consisted of 120 method sections of randomly selected empirical RAs from ISI-indexed Q1-ranked applied linguistic journals published between 2020 and 2022. The results of the study point to a significant distinction in hypotactic augmentation to register circumstantial information in comparison to other choices available to authors. Moreover, the most striking observation to emerge from the data is that a logical information structure of circumstantial meaning is mostly facilitated through hypotactic non-finite enhancement rather than its finite counterpart. This viable preference lies in elliptical, evincing, and expressive functions of hypotactic clauses that make comprehension more attainable to the readers and assist authors in fulfilling the generic conventions and communicative purposes of academic writing and managing interactive information structures. A major theoretical implication of the current research entails the significance of the interactive functions of the options available to authors which can impose priorities on the system of choices within the context of information.
Securin regulates the spatiotemporal dynamics of separase
Authors: Sorensen Turpin Christopher G. , Sloan Dillon , LaForest Marian , Klebanow Lindsey , Mitchell Diana , Severson Aaron F. , Bembenek Joshua N.
Published: November 2024

Separase regulates multiple aspects of the metaphase-to-anaphase transition. Separase cleaves cohesin to allow chromosome segregation and localizes to vesicles to promote exocytosis. The anaphase-promoting complex/cyclosome (APC/C) activates separase by ubiquitinating its inhibitory chaperone, securin, triggering its degradation. How this pathway controls the exocytic function of separase is unknown. During meiosis I, securin is degraded over several minutes, while separase rapidly relocalizes from kinetochore structures at the spindle and cortex to sites of action on chromosomes and vesicles at anaphase onset. The loss of cohesin coincides with the relocalization of separase to the chromosome midbivalent at anaphase onset. APC/C depletion prevents separase relocalization, while securin depletion causes precocious separase relocalization. Expression of non-degradable securin inhibits chromosome segregation, exocytosis, and separase localization to vesicles but not to the anaphase spindle. We conclude that APC/C-mediated securin degradation controls separase localization. This spatiotemporal regulation will impact the effective local concentration of separase for more precise targeting of substrates in anaphase.
PINK1 controls RTN3L-mediated ER autophagy by regulating peripheral tubule junctions
Authors: Chidambaram Ravi , Kumar Kamal , Parashar Smriti , Ramachandran Gowsalya , Chen Shuliang , Ferro-Novick Susan
Published: November 2024

Here, we report that the RTN3L–SEC24C endoplasmic reticulum autophagy (ER-phagy) receptor complex, the CUL3KLHL12 E3 ligase that ubiquitinates RTN3L, and the FIP200 autophagy initiating protein, target mutant proinsulin (Akita) condensates for lysosomal delivery at ER tubule junctions. When delivery was blocked, Akita condensates accumulated in the ER. In exploring the role of tubulation in these events, we unexpectedly found that loss of the Parkinson’s disease protein, PINK1, reduced peripheral tubule junctions and blocked ER-phagy. Overexpression of the PINK1 kinase substrate, DRP1, increased junctions, reduced Akita condensate accumulation, and restored lysosomal delivery in PINK1-depleted cells. DRP1 is a dual-functioning protein that promotes ER tubulation and severs mitochondria at ER–mitochondria contact sites. DRP1-dependent ER tubulating activity was sufficient for suppression. Supporting these findings, we observed PINK1 associating with ER tubules. Our findings show that PINK1 shapes the ER to target misfolded proinsulin for RTN3L–SEC24C–mediated macro-ER-phagy at defined ER sites called peripheral junctions. These observations may have important implications for understanding Parkinson’s disease.
Structure and selectivity of a glutamate-specific TAXI TRAP binding protein from Vibrio cholerae
Authors: Davies Joseph F.S. , Daab Andrew , Massouh Nicholas , Kirkland Corey , Strongitharm Bernadette , Leech Andrew , Farré Marta , Thomas Gavin H. , Mulligan Christopher
Published: November 2024

Tripartite ATP-independent periplasmic (TRAP) transporters are widespread in prokaryotes and are responsible for the transport of a variety of different ligands, primarily organic acids. TRAP transporters can be divided into two subclasses; DctP-type and TAXI type, which share the same overall architecture and substrate-binding protein requirement. DctP-type transporters are very well studied and have been shown to transport a range of compounds including dicarboxylates, keto acids, and sugar acids. However, TAXI-type transporters are relatively poorly understood. To address this gap in our understanding, we have structurally and biochemically characterized VC0430 from Vibrio cholerae. We show it is a monomeric, high affinity glutamate-binding protein, which we thus rename VcGluP. VcGluP is stereoselective, binding the L-isomer preferentially, and can also bind L-glutamine and L-pyroglutamate with lower affinity. Structural characterization of ligand-bound VcGluP revealed details of its binding site and biophysical characterization of binding site mutants revealed the substrate binding determinants, which differ substantially from those of DctP-type TRAPs. Finally, we have analyzed the interaction between VcGluP and its cognate membrane component, VcGluQM (formerly VC0429) in silico, revealing an architecture hitherto unseen. To our knowledge, this is the first transporter in V. cholerae to be identified as specific to glutamate, which plays a key role in the osmoadaptation of V. cholerae, making this transporter a potential therapeutic target.
Nonassociative gauge gravity theories with R-flux star products and Batalin–Vilkovisky quantization in algebraic quantum field theory
Authors: Vacaru Sergiu I
Published: November 2024

Nonassociative modifications of general relativity, GR, and quantum gravity, QG, models naturally arise as star product and R-flux deformations considered in string/M-theory. Such nonassociative and noncommutative geometric and quantum information theories were formulated on phase spaces defined as cotangent Lorentz bundles enabled with nonassociative symmetric and nonsymmetric metrics and nonlinear and linear connection structures. We outline the analytic methods and proofs that corresponding geometric flow evolution and dynamical field equations can be decoupled and integrated in certain general off-diagonal forms. New classes of solutions describing nonassociative black holes, wormholes, and locally anisotropic cosmological configurations are constructed using such methods. We develop the Batalin–Vilkovisky, BV, formalism for quantizing modified gravity theories, MGTs, involving twisted star products and semi-classical models of nonassociative gauge gravity with de Sitter/affine/ Poincaré double structure groups. Such theories can be projected on Lorentz spacetime manifolds in certain forms equivalent to GR or MGTs with torsion generalizations etc. We study the properties of the classical and quantum BV operators for nonassociative phase spaces and nonassociative gauge gravity. Recent results and methods from algebraic QFT are generalized to involve nonassociative star product deformations of the anomalous master Ward identity. Such constructions are elaborated in a nonassociative BV perspective and for developing non-perturbative methods in QG.
Determining the viscosity function from the boundary measurements for the Stokes and the Navier–Stokes equations
Authors: Liu Genqian
Published: November 2024

In this paper, by combining Heck-Li-Wang’s theorem in three dimensions, Lai-Uhlmann-Wang’s theorem as well as Imanuvilov–Yamamoto’s theorem in two dimensions with our new conclusion (in any dimension), we give an answer to an open problem that asks whether one can determine the viscosity function for the Stokes equations and for the Navier–Stokes equations by boundary measurements on an arbitrary bounded domain in

R

n

, (

n
=
2
,
3

). More precisely, we show the global uniqueness for the inverse boundary value problems associated with the Stokes equations in three-dimensional bounded domain as well as in two-dimensional simple-connected bounded domain, with the Navier–Stokes equations in two- or three-dimensional bounded domain.
Second-harmonic and sum-frequency generation from dielectric metasurfaces empowered by multiple quasibound states in the continuum
Authors: Liu Tingting , Qin Meibao , Tu Xu , Liu Yuebo , Wu Feng , Xiao Shuyuan
Published: November 2024

All-dielectric metasurfaces associated with the physics of bound states in the continuum (BICs) provide a novel platform to enhance nonlinear effects at the nanoscale. In this work, we demonstrate sharp enhancements of second-order nonlinear processes including second-harmonic (SHG) and sum-frequency generation (SFG) from a dielectric metasurface with the assistance of multiple quasi-BIC resonances at different input wavelengths. By resonantly pumping the AlGaAs metasurface under oblique incidence, nonlinear emissions are significantly enhanced across the visible wavelength regime from 500 nm to 600 nm. Thanks to the presence of multiple quasi-BIC resonances in the metasurface, enhanced SH signals at the respective nonlinear wavelengths can be achieved, and the SF emissions at 10 different wavelengths is further implemented and boosted by simultaneous excitations of any two quasi-BIC resonances. High-efficiency second-order nonlinear processes assisted by multiple quasi-BIC resonances present the potential to expand the functionalities of quasi-BIC metasurfaces in the nonlinear regime.
High-performance Teraherz photodetection in 2D materials and topological materials
Authors: Wei Yingdong , Bao Zhaowen , Wu Hongfei , Zhang Yunduo , Wen Yuanfeng , Hu Zhen , Pan Xiaokai , Lan Shiqi , Zhang Libo , Wang Lin , Chen Xiaoshuang
Published: November 2024

Photodetectors (PDs) leveraging two-dimensional (2D) materials and topological materials have garnered substantial interest due to their exceptional electronic and optoelectronic characteristics. These materials, including 2D semimetals like graphene, semiconducting transition metal dichalcogenides, and topological insulators such as bismuth selenide, exhibit a broad array of bandgap values and unique photon interaction properties. To date, numerous high-performance PDs using these materials have been documented, showing significant potential in terahertz (THz) frequency applications. This review presents a comprehensive examination of PDs based on 2D and topological materials, focusing on the THz frequency. Initially, an insight into the photocurrent generation mechanisms within these materials is provided, alongside a discussion of the figure-of-merits, such as responsivity and detectivity, which are crucial for evaluating PD performance. The recent advancements in THz photodetection are then highlighted, noting exceptional attributes such as high sensitivity, ultrafast response, broad spectral operation, and anisotropic detection capabilities, based on cutting-edge devices. Early-stage applications and the integration potential of these PDs in various technologies are also explored. Concluding, the manuscript offers a forward-looking perspective, outlining ongoing challenges, future research directions, and practical advice for developing next-generation THz PDs, aiming to inspire continued innovation in this rapidly evolving field.
Calibration-free thickness and temperature measurement of oil films using broadband near-infrared absorption spectroscopy
Authors: Bonarens Matthias , Goet Gabriele , Auernhammer Ariane , Hansemann Clemens , Wagner Steven , Daun Kyle J
Published: November 2024

This paper assesses broadband absorption spectroscopy for calibration-free, single-ended thickness and temperature measurements of thin liquid films with a free interface using spectrally resolved intensity measurements. The spectroscopic properties of the liquid in question, here an oil lubricant, are characterized using a Fourier transform infrared spectrometer. This data forms the basis for a measurement model that is used to infer the thickness and temperature of films wetting metal surfaces based on broadband spectral transmission measurements. The technique is demonstrated by inferring the properties of static films of known properties as well as free films on a rotating metal disk.
Flexible pressure sensor with metallic reinforcement and graphene nanowalls for wearable electronics device
Authors: Zhang Jingzhe , Shen Honglie , Mao Weibiao , Wang Zehui , Liao Bingjie , Li Yufang , Wu Tianru
Published: November 2024

In recent years, flexible pressure sensors have been seen widespread adoption in various fields such as electronic skin, smart wearables, and human–computer interaction systems. Owing to the electrical conductivity and adaptability to flexible substrates, vertical graphene nanowalls (VGNs) have recently been recognized as promising materials for pressure-sensing applications. Our study presented the synthesis of high-quality VGNs via plasma enhanced chemical vapor deposition and the incorporation of a metal layer by electron beam evaporation, forming a stacked structure of VGNs/Metal/VGNs. Metal nanoparticles attached to the edges and surfaces of graphene nanosheets can alter the charge transport paths within the material to enhance the responsiveness of the sensor. This layered structure effectively fulfilled the requirements of flexible pressure sensors, exhibiting high sensitivity (40.15 kPa−1), low response time (88 ms), and short recovery time (97 ms). The pressure sensitivity remained intact even after 1000 bending cycles. Additionally, the factors contributing to the impressive pressure-sensing performance of this composite were found and its capability to detect human pulse and finger flexion signals was demonstrated, making it a promising candidate for applications of wearable electronics devices.
Existence of bounded solutions for a non-periodic sublinear equation with an obstacle*
Authors: Peng Yaqun
Published: November 2024

We prove that the sublinear equation with an obstacle

{

u
¨

+

u
α

=
p

(
t
)

,
 
 
0
 <
α
<
1
,

u
≥
0
,

u

(

t
0

)

=
0
⇒

u
˙

(

t
0
+

)

=
−

u
˙

(

t
0
−

)

has infinitely many bounded solutions for non-periodic forcing p by the implicit function theorem and the non-periodic twist maps’ theory established by Kunze and Ortega.
Measurements and kinetic modeling of O2 vibrational kinetics in O2–Ar mixtures partially dissociated by a Ns pulse discharge
Authors: Orr Keegan , Esposito Fabrizio , Armenise Iole , van den Bekerom Dirk , Adamovich I V
Published: November 2024

Vibrational kinetics of O2 is studied during the O atom recombination in an O2–Ar mixture, partially dissociated by a burst of ns discharge pulses in a heated plasma flow reactor. The time-resolved temperature in the discharge afterglow is determined by Rayleigh scattering. Time-resolved O atom number density is measured by ps Two-Photon absorption Laser Induced Fluorescence, calibrated in xenon. Time-resolved vibrational level populations of molecular oxygen, O2(v= 8–20), are measured by ps Laser Induced Fluorescence (LIF), with the absolute calibration by NO LIF. Time-resolved ozone number density is monitored by broadband UV absorption. The results are compared with the predictions of a state-specific kinetic model. The experimental data indicate a rapid initial decay of O2(v) populations generated by electron impact in the discharge, due to the vibration-translation (V–T) relaxation by O atoms. This is followed by a slower population reduction, on the time scale much longer compared to that for V–T relaxation or vibration-vibration (V–V) exchange. Both O atoms and the O2(v) populations decay on the same time scale, indicating that chemical reactions initiated by the O atom recombination result in the generation of vibrationally excited O2 molecules. These trends are reproduced by the kinetic model, which shows that the reaction of O atoms with ozone is the dominant pathway of O2(v) generation at the present conditions. The predicted relative O2(v) populations are close to the experimental results, but absolute number densities differ from the experimental data. This is likely due to uncertainties in the absolute calibration of LIF measurements and in the spectroscopic model used in the data reduction. The present work demonstrates the capability for the absolute, time-resolved measurements of vibrationally excited O2 in recombining gas flows, to quantify the energy partition in the recombination reactions.
The FinFET effect in lateral 4H-SiC and Silicon multi-gate MOSFETs
Authors: Naydenov K , Wang Q , Udrea F , Fujioka H , Tomita H , Nishiwaki T , Kumazawa T , Fujiwara H
Published: November 2024

This paper presents a comprehensive investigation on the role and manifestation of the FinFET effect in low voltage 4H-SiC MOSFETs as compared to their Si counterparts. For this purpose, a finite element model of a fabricated SiC FinFET with a fin width of 55 nm is constructed and calibrated to experimental data at a range of operating temperatures. The resulting TCAD model is then applied to examine the impact of the FinFET effect on the threshold voltage and the spatial variation of the carrier density and the drift mobility in the channel for a range of doping concentrations N

A
of the p-well. It is thereby shown that by reducing the fin width

W

fin

from conventional values

≳

500 nm down to an interval of optimal values ∼40 nm (keeping everything else constant), it is possible to enhance the channel mobility ∼2.5 times. This improvement is not only found to be much larger than the one predicted in Si (where it is ∼ 15% according to the TCAD model) but also arises at a larger fin width (for a given N

A
). In this respect, it is demonstrated that this optimal range of fin widths can be moved to even larger, more practical values by reducing the doping of the p-well. As an alternative, the on-state performance of the gate-all-around FET is also examined in detail following a similar procedure. It is hence shown that this structure can display the FinFET effect at an even larger, nearly conventional

W

fin

of ∼250 nm, whilst attaining a higher channel mobility and inversion layer density even than a stripe FinFET operated at the same overdrive. Thus, in light of all these advantages, the FinFET topology can play a key role in reducing the channel resistance of SiC power MOSFETs.
A control-oriented magnetorheological elastomer isolator for high-tech facilities: development and experimental verification
Authors: Li Wang , Li Peidong , Fu Jie , Yu Miao
Published: November 2024

To protect high-tech facilities from micro-amplitude vibrations, a control-oriented magnetorheological (MR) elastomer (MRE) isolator (MRE-I) is developed. The MRE-I, which combines features of high bearing capacity and large MR effect, works in a stacked type compression and shear mixed mode. Meanwhile, index of high magnetic-energy ratio for MRE-I, with considering both the MR effect and power consumption is defined in this paper. Firstly, the magnetic field function of the MRE-I works in mixed mode is deduced. Taking high magnetic-energy ratio as the optimization objective, and using a genetic algorithm to solve the problem, the structure parameters are obtained. Subsequently, force to displacement tests with multi-operating conditions are conducted on the prototype, demonstrating an increase of 1604.29% in output force under a medium level of magnetic field. Lastly, vibration control tests using a fuzzy controller are carried out under an excitation of 1 m s−2 in a frequency sweep condition ranging from 90 Hz to 135 Hz, reaching 40% reduction in root mean squared of acceleration response, demonstrating the feasibility of this MRE-I for time-varying, micro-amplitude and wide-band vibration control of high-tech facilities.
Analysis of thermal grooving effects on vortex penetration in vapor-diffused Nb3Sn
Authors: Lechner Eric M , Trofimova Olga , Angle Jonathan W , DiGuilio Madison C , Pudasaini Uttar
Published: November 2024

While Nb3Sn theoretically offers better superconducting radio-frequency (RF) cavity performance (Q
0 and

E

acc

) to Nb at any given temperature, peak RF magnetic fields consistently fall short of the ∼400 mT prediction. The relatively rough topography of vapor-diffused Nb3Sn is widely conjectured to be one of the factors that limit the attainable performance of Nb3Sn-coated Nb cavities prepared via Sn vapor diffusion. Here we investigate the effect of coating duration on the topography of vapor-diffused Nb3Sn on Nb and calculate the associated magnetic field enhancement and superheating field suppression factors using atomic force microscopy topographies. It is shown that the thermally grooved grain boundaries are major defects which may contribute to a substantial decrease in the achievable accelerating field. The severity of these grooves increases with total coating duration due to the deepening of thermal grooves during the coating process.
Electromagnetic properties of superconductive low-β 325 MHz half-wave resonators at low RF field
Authors: Sukhotski A , Bychanok D , Volunets H , Gilev A , Huseu S , Gurnevich E , Maksimenko S , Petrakovski V , Pakrouski A , Pobol A , Burin A , Pobol I , Zalessky V , Gusarova M , Lalayan M , Polozov S , Tamashevich Y , Cherkunov D , Kotova A , Bespalov Y , Nikiforov D , Butenko A , Syresin E , Trubnikov G
Published: November 2024

A niobium prototype and two test unjacketed 325 MHz coaxial half-wave cavities with β = 0.21 were designed, fabricated, and tested at low RF fields. Electromagnetic properties were investigated using a vector network analyzer in the frequency domain and an RF generator, directional couplers, and power detectors in the time domain (both continuous wave and pulse mode). We analyzed and compared the response of the low-beta cavity in both normal and superconducting states. We studied the relationship between the resonator parameters and coupling devices to optimize the design of the RF power coupler and field probe antenna, aiming to achieve accurate cavity characterization. We proposed a tunable power coupler design that allows for varying the coupling coefficient when operating in a vacuum at liquid helium temperature. The typical responses of the cavity in case of under-, critical-, and over-coupling conditions obtained within a single cool-down are presented and analyzed. We introduced a simplified method based on decay measurements with cavity port switching for effective cavity characterization at low RF amplitudes. This method aligns well with standard Q-factor measurement protocols and can expedite experimental investigations with small RF signals. The

Q
0

(

E
acc

)

curve for half-wave resonators at ultra-low amplitudes is analyzed and discussed. Experiments with coaxial half-wave cavities showed an almost constant Q
0 at RF fields ranging from 1 × 10−4 MV m−1 to 1 × 10−1 MV m−1. Additionally, a significant increase in the quality factor was observed after 120 ∘C baking. The presented results are discussed in the context of potential low-field applications of superconductive cavities.
Effect of dynamic resistance reduction in spiral copper-plated multifilament coated conductors
Authors: Sogabe Yusuke , Amemiya Naoyuki
Published: November 2024

Theoretically, it has been shown that the dynamic resistances of coated conductors can be reduced by decreasing their effective width through multifilamentation. In the case of copper-plated multifilament coated conductors, coupling currents are expected to worsen the effect of multifilamentation in reducing dynamic resistance. Therefore, the purpose of this study is to experimentally investigate the dynamic resistances of spiral copper-plated multifilament coated conductors, which are expected to reduce the coupling time constant in a manner similar to twisted low-T
c superconducting wires. We measured the dynamic resistance of four different samples—straight monofilament, straight multifilament, spiral monofilament, and spiral multifilament coated conductors—using the four-terminal method. We discuss the dynamic resistivity characteristics of the copper-plated multifilament coated conductors by comparing the magnetic field dependence of the dynamic resistivity, normalized by the critical current of each sample.
A quench detection method for closed-loop superconducting coils based on currents redistribution in co-windings
Authors: Hu Changhao , Lin Yi , Tan Yunfei , Wang Lei , Geng Jianzhao
Published: November 2024

Closed-loop operation of superconducting magnets can significantly reduce cryogenic heat load and enhance magnetic field stability, which has been widely applied in systems such as magnetic resonance imaging and electro-dynamic suspension. Quench detection for closed-loop superconducting magnets, especially high-T
c superconducting (HTS) magnets, has long been a challenging issue. In this paper, we derived quench-induced currents redistribution characteristics in parallel co-wound closed-loop superconducting magnets, and proposed a current-redistribution based quench detection method for such magnets. Artificial quench tests on a small scale co-wound closed-loop HTS coil were staged, with AC background magnetic field applied to simulate tough working conditions such as in HTS maglevs and HTS machines. Results show that the method can sensitively and reliably detect a quench even at its inception, long before the coil field change becoming identifiable, and the method is robust against background AC magnetic fields. This work may potentially be useful for reducing the quench damage risk in closed-loop superconducting magnet for various applications.
Time arrow without past hypothesis: a toy model explanation
Authors: Arrighi Pablo , Dowek Gilles , Durbec Amélia
Published: November 2024

The laws of Physics are time-reversible, making no qualitative distinction between the past and the future—yet we can only go towards the future. This apparent contradiction is known as the ‘arrow of time problem’. Its current resolution states that the future is the direction of increasing entropy. But entropy can only increase towards the future if it was low in the past, and past low entropy is a very strong assumption to make, because low entropy states are rather improbable, non-generic. Recent works from the Physics literature suggest, however, we may do away with this so-called ‘past hypothesis’, in the presence of reversible dynamical laws featuring expansion. We prove that this can be the case in principle, within a toy model. It consists in graphs upon which particles circulate and interact according to local reversible rules. Some rules locally shrink or expand the graph. We prove that almost all states expand; entropy always increases as a consequence of expansion—thereby providing a local explanation for the rise of an entropic arrow of time without the need for a past hypothesis. The discrete setting of this toy model allows us to deploy the full rigour of theoretical Computer Science proof techniques. It also allows for the numerical exploration of several physically-motivated variants: a time-symmetric variant; two inflationary variants; and a damping variant—which slows down thermal death. The fact that all of these models exhibit similar behaviours suggests that local reversible expansion mechanisms constitute a robust recipe for a time arrow without past hypothesis. In this qualitative sense, the explanation may therefore also be relevant at the cosmological level.
Hidden complex multistable dynamical analysis and FPGA implementation of integer-fractional order memristive-memcapacitive chaotic system
Authors: Xu Jingjing , Zhang Xiaohong , Zhong Shaojiang
Published: November 2024

A chaotic circuit based on a magnetic-controlled memristor and charge-controlled memcapacitor is proposed in this paper. The study reveals that it is a hyperchaotic system with hidden characteristics in integer-order. Furthermore, as the parameters change, the attractors exhibit rich evolutionary phenomena. Even after adjusting some parameters to very large values, the system still maintains hyperchaotic behavior. Interestingly, the basin of attraction shows the multistability of the system. Under initial value control, coexisting attractors are categorized into two types: those with initial offset-boosting behavior and nested attractors. When under parameter control, coexisting attractors are divided into two types: symmetric coexisting attractors and nested coexisting attractors. By analyzing the spectral entropy (SE) complexity of the system and using a complexity distribution diagram with two parameters and two initial values, the existence of multiple complex dynamic behaviors in the system has been verified. The fractional-order memristive-memcapacitive system based on the Grunwald-Letnikov algorithm and the five fractional-order values of q

i
(i = 1, 2, 3, 4, 5) are taken as different in the numerical simulation, it also displays multiple coexisting phenomena similar to those of the integer-order. Finally, Matlab/Simulink and DSP Builder software platform are used to design the fractional-order five-dimensional chaotic memristive-memcapacitive system, and then combined with VHDL and Verilog HDL hardware language, the proposed circuit system is verified on the EP4CE115F29C7 FPGA main chip of Cyclone IV E series. The consistency of hardware implementation and software simulation shows the correctness and feasibility of the design.