bluuebunny/crossref_metadata_2025 huggingface dataset:
L’acquisition de la morphologie verbale française par des apprenants néerlandophones à l’oral et à l’écrit
Authors: Santens Sara , Verroens Filip , Hadermann Pascale
Published: May 2022

L’objectif de cette étude est de dégager d’éventuelles différences entre l’acquisition de la morphologie verbale à l’écrit en français langue étrangère d’une part et celle à l’oral d’autre part. Nous nous sommes plus spécifiquement intéressés aux trajets que parcourent des apprenants néerlandophones dans les deux types de production, avec une attention particulière pour leur maîtrise de la finitude verbale et de l’accord sujetverbe. L’hypothèse de l’importance du type de production s’est confirmée : les deux aspects mentionnés précédemment sont mieux intégrés à l’écrit qu’à l’oral. Pour ce qui est de la morphologie silencieuse, son influence varie d’après le nombre : elle se manifeste au singulier mais n’affecte pas la 3ème personne du pluriel dans notre corpus.
Pas à pas vers l’explicitation des normes orthographiques. Un jeu numérique pour apprendre à justifier son raisonnement
Authors: Rodi Mireille , Geoffre Thierry
Published: May 2022

L’Orthodyssée des Gramest une application en ligne qui cherche à mobiliser le raisonnement orthographique et grammatical de l’élève. Dans la continuité de notre étude de l’utilisation de ce jeu, nous analysons la progression du raisonnement métagraphique d’un enfant au cours de ses interactions avec une logopédiste. Il s’agit d’étudier en quoi l’outil numérique favorise une collaboration réflexive guidant l’enfant dans une approche des normes orthographiques grammaticales. Nous présentons le protocole d’expérimentation, la grille d’analyse et les résultats issus de l’analyse des stratégies d’étayage d’une logopédiste interagissant avec une patiente sur 10 séances. Nous concluons sur le développement du raisonnement orthographique et sur les perspectives d’implémentation de ce jeu numérique dans des classes de niveau primaire.
Relation entre la compétence en compréhension écrite et la connaissance lexicale au niveau A2 en français chez les étudiants japonophones
Authors: Sugiyama Kaori
Published: May 2022

Le premier objectif de cette étude est de déterminer dans quelle mesure les résultats aux tests de compréhension écrite peuvent être prédits par des mesures de la connaissance lexicale chez les apprenants japonais de français au niveau A2. Le second est d’identifier les caractéristiques du vocabulaire requis pour acquérir le niveau A2. Pour cela, 48 étudiants ont été soumis à un test de compréhension écrite basé sur un test blanc du DELF A2, suivi d’un test de connaissance des mots portant sur les mêmes textes. Une régression multiple a été effectuée en utilisant le taux de réponses correctes comme variable explicative et le résultat au test comme variable dépendante. L’équation de régression obtenue prédit 73,5% de la variance des résultats au test. Les participants ont été classés en deux groupes : ceux qui ont réussi le test de compréhension de l’écrit et ceux dont les résultats sont insuffisants. Les réponses données par les deux groupes ont été comparées. Nous avons ainsi constaté que ce qui a fait la différence entre la réussite et l’échec sont les taux de réponses correctes pour les prépositions, les mots de fréquence moyenne-basse pouvant être déduits de l’anglais et les mots nécessitant une connaissance culturelle.
Un rituel langagier pour renforcer l’engagement interactionnel à l’école : au service du développement du langage oral et du climat de classe
Authors: Rey Véronique , Romain Christina
Published: May 2022

Notre étude porte sur l’intérêt du rituel de la fonction patrimoniale du langage (de l’école maternelle au collège) comme moyen de réduire l'écart des compétences orales entre les élèves les plus en difficulté et les autres en favorisant un climat coopératif de classe. Ce protocole a débuté en septembre 2017, pour une durée de trois ans. Cet atelier ritualisé repose à la fois sur la transmission interactionnelle des mouvements du corps, des gestes articulatoires de la langue (Baddeley etal. 1998, 2000), de textes oraux appris par coeur (chants, comptines, …) ou écoutés (contes…) reposant ainsi sur la dimension narrative et pragmatique de la langue (Rabatel 2004 ; Bernicot 2005), mais aussi sur la coopération langagière et sur l'attention conjointe (Tomasello 2000ab, 2004). Après deux ans de recherche, les résultats rendent compte de l’impact positif de ce protocole quant à la constitution du groupe-classe et à l’appropriation des pratiques orales ritualisées par les élèves.
L’organisation spatio-temporelle de la respiration chez l’enfant
Authors: Charuau Delphine , Vaxelaire Béatrice , Sock Rudolph
Published: May 2022

La respiration en parole est un phénomène complexe, interagissant en permanence avec la structure linguistique de la langue. Bien que largement étudié chez l’adulte, peu de travaux portent sur la relation entre l’organisation spatio-temporelle respiratoire et la structure linguistique chez l’enfant dont les modèles respiratoires n’ont pas encore atteint leur maturité. L’objectif de ce travail consiste à enrichir la description du développement des modèles respiratoires chez l’enfant et de comprendre la manière dont respiration et linguistique interagissent entre elles. À l’aide de la pléthysmographie respiratoire par inductance, nous avons mesuré la variation des périmètres thoracique et abdominal tout au long de la phonation, nous offrant la possibilité d’observer l’interaction respiration-syntaxe lors d’une production lue par 15 locuteurs âgés de 8 à 11 ans. Les résultats montrent que la majorité des pauses sont réalisées aux endroits prévus par la syntaxe. Par ailleurs, la plupart des pauses sont dédiées à la prise de souffle. Si la durée des pauses est sensible à la localisation syntaxique, la durée de l’inspiration n’est pas significativement impactée. Enfin, si elle est soumise à une forte variabilité inter et intra-individuelle, l’amplitude des mouvements inspiratoires est indépendante de la structure linguistique.
L’âge avancé en perspective longitudinale et ses outils : LangAge, un corpus au pluriel
Authors: El Sherbiny Ismail Eman , Gerstenberg Annette , Lupica Spagnolo Marta , Schulz Friederike , Vandenbroucke Anne
Published: May 2022

L’âge avancé en perspective longitudinale et ses outils : LangAge, un corpus au pluriel. En marge des groupes d’âge habituellement représentés dans les échantillons sociolinguistiques, LangAge se positionne comme un recueil d’entretiens et d’enregistrements vocaux consacré à l’âge avancé de la vie. Les participantes et participants sont issues de différents milieux et appartiennent pour la plupart à la tranche d’âge des 70 ans et plus. De plus, le corpus documente jusqu’à dix ans de la vie d’une partie de ces personnes âgées. Il est ainsi possible de suivre l’évolution des mêmes individus à travers plusieurs années et d’éviter, dans la comparaison de différentes couches d’âge, les difficultés habituelles des échantillons en temps réel qui ne peuvent jamais équilibrer les particularités biographiques des individus inclus. Le sous-corpus « couples » regroupe les rencontres avec dix couples durant cette période, ce qui permet d’aborder un domaine rarement étudié. LangAge est conçu, dans l’ensemble, pour contribuer à une image linguistique plus différenciée de la génération la plus âgée. Il en résulte un corpus « au pluriel » dont la plupart des transcriptions alignées et des fichiers son sont disponibles en libre accès. L’outil LaBB-CAT est utilisé pour la publication et consultation en ligne. Nous montrerons comment sa configuration tient compte de l’architecture complexe du corpus et correspond, en même temps, aux principes FAIR tout en respectant les droits de la personne.
Latrinalia, violence verbale et idéologies : étude de graffitis dans les toilettes de l’Université de Grenoble
Authors: Depau Giovanni
Published: May 2022

Cette étude porte sur l’analyse des manifestations de violence verbale à travers un corpus de graffitis des toilettes (latrinalia). Cette recherche vise à appréhender, en adoptant une approche sociopragmatique, la structuration d’une argumentation discursive, notamment dans l’espace de l’université, lieu social de partage des savoirs par antonomase. L’analyse s’appuie sur des données collectées entre 2019 et 2021 dans le campus de l’Université Grenoble Alpes (UGA). Les latrinalia, permettant aux auteurs de s’exprimer dans l’anonymat sur l’espace mural, se présentent comme un terrain particulièrement propice pour l’étude des dynamiques de la communication verbale informelle qui, parfois, donne lieu à de véritables échanges interactionnels entre plusieurs intervenants.
Perspectives of Evidence-Based Therapy Management
Authors: Kiessling Fabian , Schulz Volkmar
Published: May 2022

Background Therapeutics that specifically address biological processes often require a much finer selection of patients and subclassification of diseases. Thus, diagnostic procedures must describe the diseases in sufficient detail to allow selection of appropriate therapy and to sensitively track therapy response. Anatomical features are often not sufficient for this purpose and there is a need to image molecular and pathophysiological processes.

Method Two imaging strategies can be pursued: molecular imaging attempts to image a few biomarkers that play key roles in pathological processes. Alternatively, patterns describing a biological process can be identified from the synopsis of multiple (non-specific) imaging markers, possibly in combination with omics and other clinical findings. Here, AI-based methods are increasingly being used.

Results Both strategies of evidence-based therapy management are explained in this review article and examples and clinical successes are presented. In this context, reviews of clinically approved molecular diagnostics and decision support systems are listed. Furthermore, since reliable, representative, and sufficiently large datasets are further important prerequisites for AI-assisted multiparametric analyses, concepts are presented to make data available in a structured way, e. g., using Generative Adversarial Networks to complement databases with virtual cases and to build completely anonymous reference databases.

Conclusion Molecular imaging and computer-assisted cluster analysis of diagnostic data are complementary methods to describe pathophysiological processes. Both methods have the potential to improve (evidence-based) the future management of therapies, partly on their own but also in combined approaches.

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CT Findings in Patients with COVID-19-Compatible Symptoms but Initially Negative qPCR Test
Authors: Valentin Birte , Steuwe Andrea , Wienemann Tobias , Andree Marcel , Keitel Verena , Ljimani Alexandra , Appel Elisabeth , Köhler Marie-Helen , Rademacher Christin , Antoch Gerald , Aissa Joel
Published: May 2022

Purpose To assess whether it is possible to reliably detect patients with strong suspicion of COVID-19 despite initially negative quantitative polymerase-chain-reaction (qPCR) tests by means of computed tomography (CT).

Materials and Methods 437 patients with suspected COVID-19 but initially negative qPCR and subsequent chest CT between March 13 and November 30, 2020 were included in this retrospective study. CT findings were compared to results of successive qPCR tests (minimum of 3 qPCR tests if CT suggested infection) to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT for diagnosing COVID-19.

Results COVID-19 was diagnosed correctly with a sensitivity of 100 % [95 % confidence interval (CI): 65–100] and a specificity of 88 % [95 % CI: 84–90]. A PPV of 12 % [95 % CI: 6–22] and an NPV of 100 % [95 % CI: 99–100] were determined.

Conclusion CT is able to detect COVID-19 before qPCR in initially negative patients in this special study setting. Similar CT findings in COVID-19 and other atypical pneumonias can lead to high numbers of false-positive patients, reducing the specificity of CT.

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Colorectal cancer surveillance by colonoscopy in a prospective, population-based long-term Swiss screening study – outcomes, adherence, and costs
Authors: Zgraggen Armin , Stoffel Sandro Tiziano , Barbier Michaela Carla , Marbet Urs Albert
Published: May 2022

Background The success of colorectal cancer (CRC) screening depends mainly on screening quality, patient adherence to surveillance, and costs. Consequently, it is essential to assess the performance over time.

Methods In 2000, a closed cohort study on CRC screening in individuals aged 50 to 80 was initiated in Uri, Switzerland. Participants who chose to undergo colonoscopy were followed over 18 years. We investigated the adherence to recommended surveillance and collected baseline characteristics and colonoscopy data. Risk factors at screening for the development of advanced adenomas were analyzed. Costs for screening and follow-up were evaluated retrospectively.

Results 1278 subjects with a screening colonoscopy were included, of which 272 (21.3%; 69.5% men) had adenomas, and 83 (6.5%) had advanced adenomas. Only 59.8% participated in a follow-up colonoscopy, half of them within the recommended time interval. Individuals with advanced adenomas at screening had nearly five times the risk of developing advanced adenomas compared to individuals without adenomas (24.3% vs. 5.0%, OR 4.79 CI 2.30–9.95). Individuals without adenomas developed advanced adenomas in 4.9%, including four cases of CRC; three of them without control colonoscopy. The villous component in adenomas smaller than 10 mm was not an independent risk factor. Costs for screening and follow-up added up to CHF 1’934’521 per 1’000 persons screened, almost half of them for follow-up examinations; 60% of these costs accounted for low-risk individuals.

Conclusion Our findings suggest that follow-up of screening colonoscopy should be reconsidered in Switzerland; in particular, long-term adherence is critical. Costs for follow-up could be substantially reduced by adopting less expensive long-term screening methods for low-risk individuals.
Hemorrhages in Polycythemia Vera and Essential Thrombocythemia: Epidemiology, Description, and Risk Factors—Learnings from a Large Cohort
Authors: Nicol Christophe , Ajzenberg Nadine , Lacut Karine , Couturaud Francis , Lippert Eric , Pan-Petesch Brigitte , Ianotto Jean-Christophe
Published: May 2022

Background The management of myeloproliferative neoplasms (MPNs) is based on the reduction of thrombotic risk. The incidence, impact, and risk factors of bleedings have been less studied.

Methods All patients with polycythemia vera (n=339) or essential thrombocythemia (n=528) treated in our center are included in OBENE (Observatoire BrEstois des NEoplasies myéloprolifératives) cohort (NCT02897297). Major bleeding (MB) and clinically relevant nonmajor bleeding (CRNMB) occurring after diagnosis were included, except after leukemic transformation.

Results With a median follow-up of 8.3 years, incidence of hemorrhages was 1.85% patient/year, with an incidence of MB of 0.95% patient/year. The 10-year bleeding-free survival was 89%. The most frequent locations were digestive tract, “mouth, nose and throat,” and muscular hematoma. The case fatality rate of MB was 25%. The proportion of potentially avoidable postoperative bleeding was remarkable (17.6%). In multivariable analysis, eight risk factors of bleeding were identified: leukocytes >20 G/L at diagnosis (hazard ratio [HR]=5.13, 95% confidence interval [CI]: 1.77–14.86), secondary hemopathies (HR=2.99, 95% CI: 1.27–7.04), aspirin use at diagnosis (HR=2.11, 95% CI: 1.24–3.6), platelet count >1,000 G/L at diagnosis (HR=1.93, 95% CI: 1.11–3.36), history of hemorrhage (HR=1.82, 95% CI: 1.03–3.24), secondary cancers (HR=1.71, 95% CI: 1.01–2.89), atrial fibrillation (HR=1.66, 95% CI: 1.01–2.72), and male sex (HR=1.54, 95% CI: 1.02–2.33). The occurrence of a CRNMB increased the risk of a secondary MB (odds ratio=6.13, 95% CI: 2.86–12.6, p<0.00001). Most patients taking hydroxyurea displayed a nonmacrocytic median corpuscular value in the months preceding bleeding (51.4%).

Discussion The morbidity and mortality of bleedings in MPN should not be underestimated, and patients with platelet count >1,000 G/L and/or leukocytes >20 G/L, and possibly patients who suffered from a CRNMB could benefit from cytoreduction to reducing bleeding risk. Postoperative bleedings represent a substantial proportion of bleeding and could be better prevented.
Reporting Outcomes of Pediatric Intensive Care Unit Patients to Referring Physicians via an Electronic Health Record-Based Feedback System
Authors: Cifra Christina L. , Tigges Cody R. , Miller Sarah L. , Curl Nathaniel , Monson Christopher D. , Dukes Kimberly C. , Reisinger Heather S. , Pennathur Priyadarshini R. , Sittig Dean F. , Singh Hardeep
Published: May 2022

Background Many critically ill children are initially evaluated in front-line settings by clinicians with variable pediatric training before they are transferred to a pediatric intensive care unit (PICU). Because clinicians learn from past performance, communicating outcomes of patients back to front-line clinicians who provide pediatric emergency care could be valuable; however, referring clinicians do not consistently receive this important feedback.

Objectives Our aim was to determine the feasibility, usability, and clinical relevance of a semiautomated electronic health record (EHR)-supported system developed at a single institution to deliver timely and relevant PICU patient outcome feedback to referring emergency department (ED) physicians.

Methods Guided by the Health Information Technology Safety Framework, we iteratively designed, implemented, and evaluated a semiautomated electronic feedback system leveraging the EHR in one institution. After conducting interviews and focus groups with stakeholders to understand the PICU-ED health care work system, we designed the EHR-supported feedback system by translating stakeholder, organizational, and usability objectives into feedback process and report requirements. Over 6 months, we completed three cycles of implementation and evaluation, wherein we analyzed EHR access logs, reviewed feedback reports sent, performed usability testing, and conducted physician interviews to determine the system's feasibility, usability, and clinical relevance.

Results The EHR-supported feedback process is feasible with timely delivery and receipt of feedback reports. Usability testing revealed excellent Systems Usability Scale scores. According to physicians, the process was well-integrated into their clinical workflows and conferred minimal additional workload. Physicians also indicated that delivering and receiving consistent feedback was relevant to their clinical practice.

Conclusion An EHR-supported system to deliver timely and relevant PICU patient outcome feedback to referring ED physicians was feasible, usable, and important to physicians. Future work is needed to evaluate impact on clinical practice and patient outcomes and to investigate applicability to other clinical settings involved in similar care transitions.
The link between Fisher information and geometric discord
Authors: Lowe A. , Yurkevich I. V.
Published: May 2022

By considering an arbitrary two-qubit state, it is shown that the Fisher information is intrinsically linked to the geometric discord which allows a measure for quantum correlations beyond entanglement. The complex amplitude of oscillations of the probability density function is upper bounded by the geometric discord which subsequently results in the Fisher information being bounded by the geometric discord. This gives an experimental observable which can be used to quantify quantum correlations beyond entanglement. This observable can be used to witness quantum correlations in an interferometry experiment, and provide another avenue for quantum technologies to continue to develop.
Structured illumination with thermal imaging (SI-TI): A dynamically reconfigurable metrology for parallelized thermal transport characterization
Authors: Zheng Qiye , Chalise Divya , Jia Mingxin , Zeng Yuqiang , Zeng Minxiang , Saeidi-Javash Mortaza , Tanvir Ali N. M. , Uahengo Gottlieb , Kaur Sumanjeet , Garay Javier E. , Luo Tengfei , Zhang Yanliang , Prasher Ravi S. , Dames Chris
Published: May 2022

The recent push for the “materials by design” paradigm requires synergistic integration of scalable computation, synthesis, and characterization. Among these, techniques for efficient measurement of thermal transport can be a bottleneck limiting the experimental database size, especially for diverse materials with a range of roughness, porosity, and anisotropy. Traditional contact thermal measurements have challenges with throughput and the lack of spatially resolvable property mapping, while non-contact pump-probe laser methods generally need mirror smooth sample surfaces and also require serial raster scanning to achieve property mapping. Here, we present structured illumination with thermal imaging (SI-TI), a new thermal characterization tool based on parallelized all-optical heating and thermometry. Experiments on representative dense and porous bulk materials as well as a 3D printed thermoelectric thick film (∼50 μm) demonstrate that SI-TI (1) enables paralleled measurement of multiple regions and samples without raster scanning; (2) can dynamically adjust the heating pattern purely in software, to optimize the measurement sensitivity in different directions for anisotropic materials; and (3) can tolerate rough (∼3 μm) and scratched sample surfaces. This work highlights a new avenue in adaptivity and throughput for thermal characterization of diverse materials.
Singlet fission photovoltaics: Progress and promising pathways
Authors: Baldacchino Alexander J. , Collins Miles I. , Nielsen Michael P. , Schmidt Timothy W. , McCamey Dane R. , Tayebjee Murad J. Y.
Published: May 2022

Singlet fission is a form of multiple exciton generation, which occurs in organic chromophores when a high-energy singlet exciton separates into two lower energy triplet excitons, each with approximately half the singlet energy. Since this process is spin-allowed, it can proceed on an ultrafast timescale of less than several picoseconds, outcompeting most other loss mechanisms and reaching quantitative yields approaching 200%. Due to this high quantum efficiency, the singlet fission process shows promise as a means of reducing thermalization losses in photovoltaic cells. This would potentially allow for efficiency improvements beyond the thermodynamic limit in a single junction cell. Efforts to incorporate this process into solar photovoltaic cells have spanned a wide range of device structures over the past decade. In this review, we compare and categorize these attempts in order to assess the state of the field and identify the most promising avenues of future research and development.
Tellurium spectrometer for 1S–1P1 transitions in strontium and other alkaline-earth atoms
Authors: Akin T. G. , Hemingway Bryan , Peil Steven
Published: May 2022

We measure the spectrum of tellurium-130 in the vicinity of the 461 nm S01−P11 cycling transition in neutral strontium, a popular element for atomic clocks, quantum information, and quantum-degenerate gases. The lack of hyperfine structure in tellurium results in a spectral density of transitions nearly 50 times lower than that available in iodine, making use of tellurium as a laser-frequency reference challenging. By frequency-offset locking two lasers, we generate the large frequency shifts required to span the difference between a tellurium line and the S01−P11 resonance in strontium or other alkaline-earth atoms. The resulting laser architecture is long-term frequency stable, widely tunable, and optimizes the available laser power. The versatility of the system is demonstrated by using it to quickly switch between any strontium isotope in a magneto-optical trap and by adapting it to spectroscopy on a thermal beam with a different alkaline-earth atom.
Evaluation of thermodynamic closure models for partially reacted two-phase mixture of condensed phase explosives
Authors: Rai Nirmal K. , Aslam Tariq D.
Published: May 2022

One of the key fundamental issues that is crucial in the continuum modeling of reactive flow phenomena is the thermodynamically consistent description of reaction mixture properties. To define the mixture properties, thermodynamic closure rules that relate the properties of the individual reaction components to the mixture properties are required. In the context of reactive two-phase modeling approaches, various strategies to define the thermodynamic closures have been adopted such as pressure temperature (PT) equilibrium between the individual reaction components, pressure (specific) volume (PV) equilibrium, etc. The choice of closure rules determines the relative distribution of specific volume and energy across the reaction components that comprise the mixture. Therefore, depending on the choice of the closure, the mixture thermodynamic behavior can vary. The present work examines the effect of different closure approaches on the thermodynamic properties of the reaction mixture. The analysis is performed for a condensed phase HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) based plastic bonded explosive (PBX) 9501 explosive using four different thermodynamic closures, viz., PT equilibrium, PV equilibrium, volume temperature (VT) equilibrium, and pressure (P) equilibrium with reactants on an isentrope. The relative variations in the thermodynamic properties of the mixture are analyzed and compared under both compression and expansion loading regimes. It is shown that out of the four closure models, only PT equilibrium and P equilibrium closures lead to a thermodynamically accurate description of the mixture under both compression and expansion.
Multifunctional acoustic holography based on compact acoustic geometric-phase meta-array
Authors: Liu Bingyi , Wei Qunshuo , Su Zhaoxian , Wang Yongtian , Huang Lingling
Published: May 2022

Optical geometric-phase metasurfaces provide a robust and efficient means for light wave control by simply manipulating the spatial orientations of the in-plane anisotropic meta-atoms, where polarization conversion plays a vital role. However, the concept of acoustic geometric-phase modulation for acoustic field control remains unexplored because airborne acoustic waves lack a similar optical polarization conversion process. In this work, a new type of acoustic meta-atom with deep-subwavelength feature size is theoretically investigated and further applied to acoustic field engineering based on the emerged concept of acoustic geometric phase. Herein, tunable acoustic geometric-phase modulation of designated order is obtained via the near-field coupled orbital angular momentum transfer process, and the topological charge-multiplexed acoustic geometric phase endows our meta-arrays with multiple functionalities. Our work extends the capacity of the acoustic geometric-phase meta-arrays in high-quality acoustic field reconstruction and offers new possibilities in multifunctional acoustic meta-holograms.
Plasmonic diastereoisomer arrays with reversed circular dichroism simply controlled by deformation height
Authors: Chen Shanshan , Ji Chang-Yin , Han Yu , Liu Xing , Wang Yongtian , Liu Juan , Li Jiafang
Published: May 2022

Chirality reversal between enantiomers is of great importance in both fundamental science and practical applications in chiroptics, biomedicine, and analytical chemistry. Here, we demonstrate an abrupt sign reversal of circular dichroism (CD) between artificial plasmonic diastereoisomers, which are a kind of stereo twisted metamolecules with different strength of deformations. The sign of the CD response is reversed in the same wavelength region by simply engineering the deformation height of nanostructures. Electromagnetic multipolar analysis shows that the sign of CD is determined by the phase-controlled handedness-dependent excitations of electric quadrupole modes. The numerical simulations are further verified by experiments using a nano-kirigami fabrication method. This work reveals that under certain circumstances, the CD response of the plasmonic diastereoisomers can be very close to that of enantiomers, which is useful for the exploration of profound chiroptics, as well as for the applications in chirality switching, chiral biosensing, and chiral separation.
Simulation of interacting elastic sheets in shear flow: Insights into buckling, sliding, and reassembly of graphene nanosheets in sheared liquids
Authors: Salussolia G. , Kamal C. , Stafford J. , Pugno N. , Botto L.
Published: May 2022

In liquid-based material processing, hydrodynamic forces are known to produce severe bending deformations of two-dimensional (2D) materials such as graphene. The non-linear rotational and deformation dynamics of these atomically thin sheets is extremely sensitive to hydrodynamic particle-particle interactions. To investigate this problem, we developed a computational model of the flow dynamics of elastic sheets suspended in a linear shear flow, solving the full fluid-solid coupling problem in the two-dimensional, slender-body, Stokes flow regime. Both single and pairs of sheets in close proximity are analyzed. Despite the model being two-dimensional, the critical non-dimensional shear rate yielding single-particle buckling is comparable in order of magnitude to that reported for fully three-dimensional, disk-like sheets. For pairs of interacting sheets, hydrodynamic interactions lead either to parallel sliding or bending, depending on the value of an elasto-viscous number based on particle length. For sufficiently low bending rigidity or large shear rates, large deformations of initially stacked sheets lead to sheet reattachment after separation, unlike for the rigid case. A peeling-like dynamics where lubrication provides a viscous bonding force is observed for sheet pairs when one of the two sheets is more rigid than the other. Practical implications for graphene processing and exfoliation are discussed.
Residual stress of glass and crystalline oxide thin films responding to humidity
Authors: Nishimura Yuki , Ohta Yuma , Boll Felix , Cop Pascal , Smarsly Bernd , Kozuka Hiromitsu
Published: May 2022

Here, we demonstrate that oxide thin film devices could be affected by humidity in their in-plane stress and in substrate curvature. We prepared silica glass and ceria crystalline thin films on Si(100) wafers by the sol-gel method. Both films had “tensile” in-plane residual stress. We cycled the relative humidity between ca. 20% and 80% in the square wave and monitored the substrate curvature in situ, from which in-plane stress was calculated. The increase and decrease in humidity resulted in a decrease and an increase in tensile stress, respectively. In situ ellipsometric measurements during humidity cycles showed that both thickness and refractive index increase and decrease on the increase and decrease in humidity, respectively. This guarantees that the volume expansion and shrinkage caused by water molecule adsorption/absorption and desorption, respectively, are the origins of the response of the stress to humidity. Responding to the change in humidity, thicker silica glass films with low porosities of 1%–3% showed more sluggish change in stress, suggesting absorption/desorption of water via diffusion in siloxane network in such dense films. Silica glass films with a larger porosity showed more quick response to humidity, indicating adsorption/desorption on the pore wall as the primary cause of the response. “Compressive” stress in a silica glass film with ca. 1% porosity exhibited very slight response in stress to humidity, which was attributed to the hard diffusion of water in compressed siloxane network.
The influence of particle size on the fluid dynamics of a laser-induced plasma
Authors: Miller Clayton J. , Wainwright Elliot R. , Gottfried Jennifer L. , Abraham Joseph , Wei Liang , Pantoya Michelle L.
Published: May 2022

The interaction of a laser-induced shock wave with nanoparticles and microparticles of aluminum oxide is investigated through experiments and modeling. The chemistry and physics of the interaction between the particles and plasma generated from laser ablation shows similarities and discrete differences for the two particle sizes. For both particle sizes, early stage (<10 μs) ionization was dominant and evidenced by higher concentrations of Al II. While both sizes exhibit ionization over the same duration, the intensity of emission was greater for nanoparticles indicating greater concentrations of ionized species. Moreover, the dispersion of species was notably more elongated for microparticles while radial dispersion was more pronounced for nanoparticles with elevated drag forces. At later stages (i.e., >10 μs), oxidation reactions were dominant for both particle sizes, but the same distinctions in flow field were observed and attributed to particle drag. In all stages of interaction, microparticles expand axially with less drag that suppresses their radial expansion. As a result, the dispersion of reactive species was mapped over an up to 80% larger area for nanoparticles relative to microparticles. Results shown here can be applied toward advancing experimental diagnostics and particle-shock wave modeling and simulation efforts for energetic materials.
Thomson scattering diagnostic system for the XuanLong-50 experiment
Authors: Li H. Y. , Li S. J. , Xie Q. F. , Liu J. H. , Bai R. H. , Tao R. Y. , Lun X. C. , Li N. , Bo X. K. , Liu C. Q. , Han L. , Deng B. H.
Published: May 2022

A 15-point Thomson scattering diagnostic system is developed for ENN’s spherical torus experiment XuanLong-50 (EXL-50). A BeamTech laser with 3 J/pulse (1064 nm wavelength) at 50 Hz repetition rate is chosen for measurements during EXL-50 plasma operations. To enable measurements at low density (∼0.5 × 1018 m−3) plasma operations, the opto-mechanical subsystems are carefully designed to maximize the collection and transmission of the scattered light and to minimize the stray light level. In addition, the high bandwidth trans-impedance amplifiers and segmented high speed waveform digitizers allow for the application of muti-pulse averaging to further improve the signal-to-noise ratio. Details of the diagnostic system are described and initial experimental results are presented.
Ultra-broadband near-field magnetic shielding realized by the Halbach-like structure
Authors: Chen Xu , Guo Zhiwei , Jiang Jun , Jiang Haitao , Chen Hong
Published: May 2022

With the great developments in electronic communication technology and miniaturized electromagnetic devices, near-field magnetic shielding has attracted much attention. However, for the widely used natural magnetic shielding materials, metal and ferrite, they have the unique limitations of large Ohmic loss and heavy weight, respectively. Although a compromise solution of the shielding layer may resort to the composite structure with metal and ferrite slabs, practical magnetic shielding with broadband, high efficiency, and ultra-thinness has remained a great challenge. In this work, inspired by the effective magnetic flux path established by the Halbach array, which is constructed by stacking permanent magnet in diverse directions, we propose a physical mechanism of local magnetic moment control in artificial structures, called the “Halbach-like structure.” We demonstrate the highly efficient and ultra-broadband near-field magnetic shielding in the Halbach-like structure with patterned metal and ferrite structures. By ingeniously designing the local magnetic moment, our structure not only provides an effective method for realizing high performance magnetic shielding but also paves the way to the other near-field controls, such as the wireless power transfer, wireless communications, and magnetic resonance imaging.
3D printed metamaterial absorbers for mid-infrared surface-enhanced spectroscopy
Authors: Hendrickson-Stives Albanie K. , Kang Lei , Donahue Nicole R. , Keating Christine D. , Werner Douglas H.
Published: May 2022

The resonant nature and geometric scalability make metamaterials an ideal platform for an enhanced light–matter interaction over a broad frequency range. The mid-infrared (IR) spectral range is of great importance for vibrational spectroscopy of molecules, while IR metamaterials created from lithography-based planar nanostructures have been used to demonstrate enhanced molecular detection. Compared with visible and near-infrared, the relative long wavelengths of IR light make it possible to achieve three-dimensional (3D) IR metamaterials via the state-of-the-art 3D fabrication techniques. Here, we design and fabricate a 3D printed plasmonic metamaterial absorber (MMA), and by performing Fourier-transform IR spectroscopy, we demonstrate that a series of molecular fingerprint vibrations of glycine can be significantly enhanced by the high absorption mode supported by the 3D meta-atoms of the MMA. The observed enhanced IR detection can also be partially attributed to the improved accessibility offered by the 3D architecture of the MMA. In particular, due to capillary forces during the drying process, the microscale 3D printed features lead to selective analyte deposition in high-field regions, which provides another degree of freedom in the design of the 3D printed structures for surface-enhanced IR detection. Our study shows the flexibility of metastructures based on advanced 3D printing technology in tailoring the interaction between IR light and materials on a subwavelength scale.
Numerical calculation of Green’s function and momentum distribution for spin-polarized fermions by path integral molecular dynamics
Authors: Xiong Yunuo , Xiong Hongwei
Published: May 2022

Most recently, path integral molecular dynamics (PIMD) has been successfully applied to perform simulations of identical bosons and fermions by Hirshberg et al. In this work, we demonstrate that PIMD can be developed to calculate Green’s function and extract momentum distributions for spin-polarized fermions. In particular, we show that the momentum distribution calculated by PIMD has potential applications to numerous quantum systems, e.g., ultracold fermionic atoms in optical lattices.
p-orbital multiferroics in single-layer SiN
Authors: Feng Yangyang , Zhang Ting , Dai Ying , Huang Baibiao , Ma Yandong
Published: May 2022

Multiferroics, coupling magnetism with electric polarization, provides special opportunities for both fundamental research and device applications. The current multiferroic research in a two-dimensional lattice is invariably focused on d-orbital based systems. We alternatively show by first-principles calculations that ideal multiferroics is present in a p-orbital based lattice of single-layer SiN. Single-layer SiN is a semiconductor exhibiting intrinsic ferromagnetism and ferroelectricity simultaneously. Its magnetism correlates with the extended p–p interaction between unpaired p orbitals of N atoms. The buckled symmetry guarantees the existence of an out-of-plane electric dipole, giving rise to the ferroelectric order. More remarkably, the ferroic orders in single-layer SiN display strongly coupled physics, i.e., the spatial distribution of magnetic moments can be well controlled by the reversal of electric polarization, thereby establishing the long-sought multiferroics with strong magnetoelectric coupling. These findings not only enrich a two-dimensional multiferroic family, but also enable a wide range of device applications.
Assessing effectiveness and comfortability of a two-layer cloth mask with a high-efficiency particulate air (HEPA) insert to mitigate COVID-19 transmission
Authors: Narayan Yagya , Chatterjee Sanghamitro , Agrawal Amit , Bhardwaj Rajneesh
Published: May 2022

A face mask is essential personal protective equipment to mitigate the spread of COVID-19. While a cloth mask has the least ability to prevent the passage of infectious respiratory droplets through it compared to surgical and N95 masks, the surgical mask does not fit snugly and causes significant air leakage. The synthetic fibers in the latter reduce comfortability and are an allergen for facial eczema. Moreover, the N95 mask causes CO2 inhalation and reduces heat transfer in the nose. Therefore, the objective of the present work is to improve the effectiveness of a two-layer cloth mask by introducing an intermediate, high-efficiency particulate air (HEPA) filter layer. A significant volume of impacted droplets penetrates through a single-layer cloth mask, ejecting secondary droplets from the rear side. However, a two-layer cloth mask prevents this ejection. Despite slowing down the liquid penetration, capillary imbibition through cloth due to its hydrophilicity causes the transport of the liquid into the second layer, resulting in a thin-liquid layer at the mask's rear-side surface and contaminating it. Conversely, the HEPA filter inserted in the cloth mask prevents the imbibition, making the second cloth layer free of contamination. We attribute the impedance to the imbibition by the intermediate HEPA filter layer to its hydrophobic characteristics. We experimentally and analytically assess the role of wettability on capillary imbibition. The breathability measurements of masks show that the HEPA inserted in the cloth mask does not reduce its breathability compared to that of the surgical mask.
Plasmon-driven oxidative coupling of aniline-derivative adsorbates: A comparative study of para-ethynylaniline and para-mercaptoaniline
Authors: Chen Kexun , Wang Hui
Published: May 2022

Plasmon-driven photocatalysis has emerged as a paradigm-shifting approach, based on which the energy of photons can be judiciously harnessed to trigger interfacial molecular transformations on metallic nanostructure surfaces in a regioselective manner with nanoscale precision. Over the past decade, the formation of aromatic azo compounds through plasmon-driven oxidative coupling of thiolated aniline-derivative adsorbates has become a testbed for developing detailed mechanistic understanding of plasmon-mediated photochemistry. Such photocatalytic bimolecular coupling reactions may occur not only between thiolated aniline-derivative adsorbates but also between their nonthiolated analogs. How the nonthiolated adsorbates behave differently from their thiolated counterparts during the plasmon-driven coupling reactions, however, remains largely unexplored. Here, we systematically compare an alkynylated aniline-derivative, para-ethynylaniline, to its thiolated counterpart, para-mercaptoaniline, in terms of their adsorption conformations, structural flexibility, photochemical reactivity, and transforming kinetics on Ag nanophotocatalyst surfaces. We employ surface-enhanced Raman scattering as an in situ spectroscopic tool to track the detailed structural evolution of the transforming molecular adsorbates in real time during the plasmon-driven coupling reactions. Rigorous analysis of the spectroscopic results, further aided by density functional theory calculations, lays an insightful knowledge foundation that enables us to elucidate how the alteration of the chemical nature of metal–adsorbate interactions profoundly influences the transforming behaviors of the molecular adsorbates during plasmon-driven photocatalytic reactions.
Re-examining the assumption of dominant regional wind and fire spread directions
Authors: Shmuel Assaf , Heifetz Eyal
Published: May 2022

The goal of decreasing wildfire hazard as much as possible, using minimal fuel treatments, has led to increasing scholarly interest in fuel reduction spatial optimisation. Most models in the field rest on the assumption of a known wind direction and a corresponding dominant direction of fire spread, and plan firebreaks in perpendicular directions. This strategy is effective when the wind blows in the hypothesised direction, but is quite ineffective when the wind direction is parallel to the firebreaks. In this article, we re-examine this assumption using a global fire dataset covering more than a decade. We perform a variety of circular statistical analyses including circular variance and principal component analysis (PCA). We find that the direction of fire spread in most regions is not limited to a single direction. We also find that the wind direction during fire weather is characterised by a high variance in a substantial fraction of regions around the globe. We validate this finding with a dataset comprised of over a hundred meteorological stations in Israel. We conclude that forest management should consider regional historical data of wind directions and fire spread directions, but also should plan firebreaks so that they are effective in various fire scenarios.
New insights into IRE1α activation and function in anti-tumor immunity
Authors: Logue Susan E. , Gorman Adrienne M. , Samali Afshin
Published: May 2022

Logue, Gorman, and Samali highlight a study by Guttman and colleagues (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202111068) that shows exogenous antigen peptides imported into the ER can activate the ER stress sensor IRE1α, attenuating cross-presentation by dendritic cells.
Development of the university students’ mental models on direct current*
Authors: Durukan Ümmü Gülsüm , Sağlam Arslan Ayşegül
Published: May 2022

This study aims to analyze the effects of the teaching sequence based on adidactical situations and learning styles on the development and change of the university students’ understanding levels and mental models about direct current. The study was carried out within the framework of didactical engineering. The sample of this study consisted of 27 students of the Science Teacher Training Program. The students’ learning styles were assessed and identified through Gregorc style delineator. The data gathered through the achievement test and clinical interviews were analyzed in a two-stage process: (1) the understanding levels and (2) the mental model characteristics and matrices. The review of data on understanding levels revealed that a significant number of students respond to the questions at the level of (MU) and (PU) in the pre-implementation; at the level of (PU) and (LU) in the post-implementation; and at the level of (PU) in the deferred implementation. The students’ mental models generally exhibited the characteristics of the synthesis and initial model types. The findings reached through the study revealed that the designed teaching sequence based on adidactical situations and learning style had a positive effect on the advances registered in the students’ understanding levels and mental model development regarding direct current.