bluuebunny/crossref_metadata_2025 huggingface dataset:
Connectivity between nidopallium caudolateral and visual pathways in color perception of zebra finches
Authors: Hsiao Yi-Tse , Chen Ta-Ching , Yu Pin-Huan , Huang Ding-Siang , Hu Fung-Rong , Chuong Cheng-Ming , Chang Fang-Chia
Published: November 2020

Researchers demonstrated an elegant ability for red discrimination in zebra finches. It is interested to understand whether red activates exhibit much stronger response than other colors in neural network levels. To reveal the question, local field potentials (LFPs) was recorded and analyzed in two visual pathways, the thalamofugal and the tectofugal pathways, of zebra finches. Human studies demonstrate visual associated telencephalons communicate with higher order brain areas such as prefrontal cortex. The present study determined whether a comparable transmission occurs in zebra finches. Telencephalic regions of the thalamofugal (the visual Wulst) and the tectofugal pathway (the entopallium) with their higher order telencephalon, nidopallium caudolateral (NCL) were simultaneously recorded. LFPs of relay nuclei (the nucleus rotundus, ROT) of tectofugal pathway were also acquired. We demonstrated that LFP powers in the tectofugal pathway were higher than those in the thalamofugal pathway when illuminating blue lights. In addition, the LFP synchronization was stronger between the entopallium and NCL. LFPs also revealed a higher Granger causality from the direction of entopallium to NCL and from ROT to entopallium. These results suggest that zebra finches’ tectofugal pathway predominately processing color information from ROT to NCL, relayed by entopallium, and blue could trigger the strongest response.
Signatures of optical phase transitions in superradiant and subradiant atomic arrays
Authors: Parmee Christopher D. , Ruostekoski Janne
Published: November 2020

Resonant light interacting with matter supports different phases of a polarisable medium, and optical bistability where two phases coexist. Such phases have previously been actively studied in cavities. Here, we identify signatures of optical phase transitions and optical bistability mapped onto scattered light in free-space planar arrays of cold atoms. Methods on how to explore such systems in superradiant and extreme subradiant states are proposed. The cooperativity threshold and intensity regimes for the intrinsic optical bistability, supported by resonant dipole-dipole interactions alone, are derived in several cases of interest analytically. Subradiant states require lower intensities, but stronger cooperativity for the existence of non-trivial phases than superradiant states. The transmitted light reveals phase transitions and bistability that are predicted by mean-field theory as large jumps in coherent and incoherent signals and hysteresis. In the quantum solution, traces of phase transitions are identified in enhanced quantum fluctuations of excited level populations.
Distinct influences of large-scale circulation and regional feedbacks in two exceptional 2019 European heatwaves
Authors: Sousa Pedro M. , Barriopedro David , García-Herrera Ricardo , Ordóñez Carlos , Soares Pedro M. M. , Trigo Ricardo M.
Published: November 2020

Two separate heatwaves affected western Europe in June and July 2019, in particular France, Belgium, the Netherlands, western Germany and northeastern Spain. Here we compare the European 2019 summer temperatures to multi-proxy reconstructions of temperatures since 1500, and analyze the relative influence of synoptic conditions and soil-atmosphere feedbacks on both heatwave events. We find that a subtropical ridge was a common synoptic set-up to both heatwaves. However, whereas the June heatwave was mostly associated with warm advection of a Saharan air mass intrusion, land surface processes were relevant for the magnitude of the July heatwave. Enhanced radiative fluxes and precipitation reduction during early July added to the soil moisture deficit that had been initiated by the June heatwave. We show this deficit was larger than it would have been in the past decades, pointing to climate change imprint. We conclude that land-atmosphere feedbacks as well as remote influences through northward propagation of dryness contributed to the exceptional intensity of the July heatwave.
High-precision methane isotopic abundance analysis using near-infrared absorption spectroscopy at 100 Torr
Authors: Liu Zhiwei , Zheng Chuantao , Zhang Tianyu , Zhang Yu , Wang Yiding , Tittel Frank K.
Published: November 2020

A near-infrared methane (CH4) sensor system for carbon isotopic abundance analysis was developed based on laser absorption spectroscopy (LAS).
Novel fluorescent nitrogen-doped carbon dots derived from Panax notoginseng for bioimaging and high selectivity detection of Cr6+
Authors: Zheng Xiaodan , Qin Kunhao , He Liping , Ding Yafang , Luo Qian , Zhang Chunting , Cui Xiuming , Tan Yong , Li Lina , Wei Yunlin
Published: November 2020

Schematic of the synthetic route to fluorescent Pn-CDs and Pn N-CDs and their applications in the bioimaging and detection of Cr6+.
Highly biocompatible and recyclable biomimetic nanoparticles for antibiotic-resistant bacteria infection
Authors: Chen Bei , Li Fangfang , Zhu Xin Kai , Xie Wei , Hu Xue , Zan Ming Hui , Li XueKe , Li Qian-Ying , Guo Shi-Shang , Zhao Xing-Zhong , Jiang Ying-an , Cao Zhijian , Liu Wei
Published: November 2020

Highly biocompatible biomimetic nanoparticles for antibiotic-resistant bacteria infection by photothermal therapy.
The effect of halogen bonding on protonated hexacyanoferrate networks in hexacyanoferrates of halogenopyridines
Authors: Jakupec Nikola , Fotović Luka , Stilinović Vladimir
Published: November 2020

Hydrogen bonded network of protonated hexacyanoferrate anions is determined by geometry and halogen bonding proclivity of the halogenopyridinium cation.
2D MOF-derived porous NiCoSe nanosheet arrays on Ni foam for overall water splitting
Authors: Zhou Yue , Chen Yanli , Wei Maobin , Fan Hougang , Liu Xiaoyan , Liu Qianyu , Liu Yumeng , Cao Jian , Yang Lili
Published: November 2020

A novel 2D porous NiCoSe nanosheet arrays were grown on Ni foam using ZIF-67 as precursors, which exhibited outstanding bifunctional electrocatalytic activity and superior durability for overall water splitting.
Self-assembly of diphenylalanine peptides on graphene via detailed atomistic simulations
Authors: Rissanou Anastassia N. , Keliri Andriani , Arnittali Maria , Harmandaris Vagelis
Published: November 2020

(a) Characteristic snapshot of 150FF peptides in aqueous solution at 300 K. (b) Characteristic snapshot of an interfacial graphene/FF system with 300FF in aqueous solution at 300 K. (c) Atom density profiles of phenyl rings and the backbone as a function of distance from the surface of graphene.
Revealing the role of nitrogen dopants in tuning the electronic and optical properties of graphene quantum dots via a TD-DFT study
Authors: Yang Min , Lian Zan , Si Chaowei , Li Bo
Published: November 2020

The tunable electronic and optical properties of graphene quantum dots achieved by nitrogen doping
Directional control of surface rolling molecules exploiting non-uniform heat-induced substrates
Authors: Nemati Alireza , Nejat Pishkenari Hossein , Meghdari Ali , Ge Shuzhi Sam
Published: November 2020

Exploiting a surface subjected to a temperature gradient to convert the diffusive motion of nanocars to guided directional motion.
When rare earth meets carbon nanodots: mechanisms, applications and outlook
Authors: Zhang Mengzhen , Zhai Xinyun , Sun Mingzi , Ma Tengfei , Huang Yongkang , Huang Bolong , Du Yaping , Yan Chunhua
Published: November 2020

The brand-new RE–CND hybrids are systematically reviewed for the first time, providing recent advances, interdisciplinary opportunities and challenges for researchers.
Carbonyl group and carbon dioxide activation by rare-earth-metal complexes
Authors: Bayer Uwe , Anwander Reiner
Published: November 2020

Not just hilariously effective baits! Rare-earth-metal compounds selectively react with aldehydes, ketones and carbon dioxide to generate isolable compounds as crucial intermediates in organic synthesis and homogenous catalysis.
The role of metal oxide nanoparticles,Escherichia coli, andLactobacillus rhamnosuson small intestinal enzyme activity
Authors: García-Rodríguez Alba , Moreno-Olivas Fabiola , Marcos Ricard , Tako Elad , Marques Cláudia N. H. , Mahler Gretchen J.
Published: November 2020

To understand the effects of engineered nanomaterials added intentionally and unintentionally to food, we improved a gastrointestinalin vitromodel usingin vitrodigested nanoparticles, Caco-2/HT29-MTX cells and gut microbiota.
A high performance N-doped graphene nanoribbon based spintronic device applicable with a wide range of adatoms
Authors: Rezapour M. Reza , Lee Geunsik , Kim Kwang S.
Published: November 2020

Designing and fabricating nanosize spintronic devices is a crucial task to develop information technology of the future.
mTOR–mLST8 interaction: hot spot identification through quantum biochemistry calculations
Authors: Santos de Oliveira Francisco Lucas , Vieira Carletti Jaqueline , Azevedo Francisca Fernanda Nunes , Freitas de Sousa Francisca Joseli , Caetano Ewerton W. S. , Freire Valder Nogueira , Zanatta Geancarlo
Published: November 2020

Quantum calculation of mTOR–mLST8 interaction.
One-pot synthesis of 3-hydroxy-2-oxindoles via acyloin rearrangements of 2-hydroxy-indolin-3-ones generated in situ from 2-alkynyl arylazides
Authors: Zhou Zhiqiang , Xu Yao , Zhu Boyu , Li Ping , Hu Guiwen , Yang Fan , Xu Shijie , Zhang Xiaoxiang
Published: November 2020

A novel one-pot method to prepare 3-hydroxy-2-oxindoles via acyloin rearrangements of 2-hydroxy-indolin-3-ones generated in situ from 2-alkynyl arylazides has been described.
Enantioselective total synthesis of (+)-ieodomycin A, (+)-ieodomycin B, and their three stereoisomers
Authors: Choi Du-Bong , Choi Hansol , Lee Jihoon , Lee Yeon-Ju , Lee Hyi-Seung , Joo Jung Min , Lee Jong Seok
Published: November 2020

Enantioselective routes for the total synthesis of ieodomycins A & B, and three stereochemical analogues of ieodomycin B via a late-stage elaboration of the side chain.
Dynamic covalent exchange in poly(thioether anhydrides)
Authors: Tillman Kelly R. , Meacham Rebecca , Highmoore Julian F. , Barankovich Mikenzie , Witkowski Ana M. , Mather Patrick T. , Graf Tyler , Shipp Devon A.
Published: November 2020

Dynamic covalent exchange (DCE) of anhydride moieties is examined in both model compounds and network polymers.
TLC-spectrodensitometric method for simultaneous determination of dapagliflozin and rosuvastatin in rabbit plasma: stability indicating assay and kinetic studies
Authors: Abbas Noha S. , Derayea Sayed M. , Omar Mahmoud A. , Saleh Gamal A.
Published: November 2020

Mixtures of DAPA and ROSV were separated using ethyl acetate : methanol (5 : 0.1 v/v) as mobile phase and applied in plasma and urine samples in addition to stability indicating and kinetic studies.
When biomolecules meet 2-hydrazinopyrazine: from theory through experiment to molecular levels using a wide spectrum of techniques
Authors: Mech Paulina , Makowski Mariusz , Kawiak Anna , Chylewska Agnieszka
Published: November 2020

Structure, ionic forms, hydrophilic and non-cytotoxic character of 2-hydrazinopyrazine with stronger affinity to BSA than DNA were proved.
Molecular engineering of the last-generation CNTs in smart cancer therapy by grafting PEG–PLGA–riboflavin
Authors: Sohrabi Somayeh , Khedri Mohammad , Maleki Reza , Keshavarz Moraveji Mostafa
Published: November 2020

In this work, the effect of environment and additives on the self-assembly and delivery of doxorubicin (DOX) have been studied.
A multifunctional use of bis(methylene)bis(5-bromo-2-hydroxyl salicyloylhydrazone): from metal sensing to ambient catalysis of A3 coupling reactions
Authors: Peewasan Krisana , Merkel Marcel P. , Fuhr Olaf , Anson Christopher E. , Powell Annie K.
Published: November 2020

3D-complexes of the ligand H6L = bis(methylene)bis(5-bromo-2-hydroxyl salicyloylhydrazone) not only show promising fluorescence sensing properties but are also effective A3 coupling reagents.
Enhanced active oxidative species generation over Fe-doped defective TiO2 nanosheets for boosted photodegradation
Authors: Gao Xintong , Zhang Shuai , Liu Jingchao , Xu Shiqi , Li Zenghe
Published: November 2020

Defect-rich ultrathin TiO2 nanosheets with tunable Fe doping realize the efficient generation of active oxidative species for boosted dye/antibiotic photodegradation.
Correction: Variation in surface properties, metabolic capping, and antibacterial activity of biosynthesized silver nanoparticles: comparison of bio-fabrication potential in phytohormone-regulated cell cultures and naturally grown plants
Authors: Khan Tariq , Ali Gul Shad
Published: November 2020

Correction for ‘Variation in surface properties, metabolic capping, and antibacterial activity of biosynthesized silver nanoparticles: comparison of bio-fabrication potential in phytohormone-regulated cell cultures and naturally grown plants’ by Tariq Khan et al., RSC Adv., 2020, 10, 38831–38840, DOI: 10.1039/D0RA08419K.
Electrocatalytic redox neutral [3 + 2] annulation of N-cyclopropylanilines and alkenes
Authors: Wang Qi , Wang Qile , Zhang Yuexiang , Mohamed Yasmine M. , Pacheco Carlos , Zheng Nan , Zare Richard N. , Chen Hao
Published: November 2020

We report the use of an online electrochemistry/mass spectrometry platform to develop a redox neutral electrosynthesis of 5-membered rings via [3 + 2] annulation of N-cyclopropylanilines and alkenes, without additional oxidant, reductant or catalyst.
Synthesis, structure, and luminescence properties of layered oxychloride Ba3Y2O5Cl2
Authors: Iwasa Yuki , Su Yu , Tsuchiya Yoshinori , Tatsuda Makoto , Kishio Kohji , Yanagida Takayuki , Takada Fumi , Nishio Taichiro , Tsujimoto Yoshihiro , Fujii Kotaro , Yashima Masatomo , Ogino Hiraku
Published: November 2020

We report the synthesis, crystal structure, and optical properties of a new layered perovskite oxychloride, Ba3Y2O5Cl2.
Exploring Barriers to Doctoral Education in Communication Sciences and Disorders: Insights From Practicing Professionals
Authors: Tucker Denise A. , Compton Mary V. , Allen Sarah J. , Mayo Robert , Hooper Celia , Ogletree Billy , Flynn Perry , Frazier Ashley , McMurry Summer
Published: November 2020

Purpose

The intended purpose of this research note is to share the findings of a needs assessment online survey of speech and hearing professionals practicing in North Carolina to explore their interest in pursuing a research-focused PhD in Communication Sciences and Disorders (CSD) and to document their perceptions of barriers to pursing a PhD in CSD. In view of the well-documented shortage of doctor of philosophy (PhD) faculty to attract, retain, and mentor doctoral students to advance research and to prepare future speech and hearing professionals, CSD faculty must assess the needs, perceptions, and barriers prospective students encounter when considering pursuing a doctoral research degree in CSD.

Method

The article describes the results of a survey of 242 speech and hearing professionals to investigate their interest in obtaining an academic research-focused PhD in CSD and to solicit their perceived barriers to pursuing a research doctoral degree in CSD.

Results

Two thirds of the respondents (63.6%) reported that they had considered pursuing a PhD in CSD. Desire for knowledge, desire to teach, and work advancement were the top reasons given for pursuing a PhD in CSD. Eighty-two percent of respondents had no interest in traditional full-time study. Forty-two percent of respondents indicated that they would be interested in part-time and distance doctoral study. The barriers of time, distance, and money emerged as those most frequently identified barriers by respondents.

Conclusion

The implications inform higher education faculty on how they can best address the needs of an untapped pool of prospective doctoral students in CSD.
Spatial–temporal evolution of photospheric weak-field shifts in solar cycles 21–24
Authors: Mursula K. , Getachew T. , Virtanen I. I.
Published: November 2020

Context. Weak magnetic field elements make a dominant contribution to the total magnetic field on the solar surface. Even so, little is known of their long-term occurrence.

Aims. We study the long-term spatial–temporal evolution of the weak-field shift and skewness of the distribution of photospheric magnetic field values during solar cycles 21−24 in order to clarify the role and relation of the weak field values to the overall magnetic field evolution.

Methods. We used Wilcox Solar Observatory (WSO) and the Synoptic Optical Long-term Investigations of the Sun Vector SpectroMagnetograph synoptic maps to calculate weak-field shifts for each latitude bin of each synoptic map, and thereby constructed a time–latitude butterfly diagram for shifts. We also calculated butterfly diagrams for skewness for all field values and for weak field values only.

Results. The weak-field shifts and (full-field) skewness depict a similar spatial–temporal solar cycle evolution to that of the large-scale surface magnetic field. The field distribution has a systematic non-zero weak-field shift and a large skewness already at (and after) the emergence of the active region, even at the highest resolution. We find evidence for coalescence of opposite-polarity fields during the surge evolution. This is clearly more effective at the supergranulation scale. However, a similar dependence of magnetic field coalescence on spatial resolution was not found in the unipolar regions around the poles.

Conclusions. Our results give evidence for the preference of even the weakest field elements toward the prevailing magnetic polarity since the emergence of an active region, and for a systematic coalescence of stronger magnetic fields of opposite polarities to produce weak fields during surge evolution and at the poles. We also find that the supergranulation process is reduced or turned off in the unipolar regions around the poles. These observations improve the understanding not only of the development of the weakest magnetic field elements, but also of the dynamics of magnetic fields at large, and even of processes below the solar surface.
Regularity analysis for an abstract thermoelastic system with inertial term
Authors: Kuang Zhaobin , Liu Zhuangyi , Fernández Sare Hugo D.
Published: November 2020

In this paper, we provide a complete regularity analysis for the following abstract thermoelastic system with inertial term

[see formula in PDF]

where A is a self-adjoint, positive definite operator on a complex Hilbert space H and

[see formula in PDF]

It is regarded as the second part of Fernández Sare et al. [J. Diff. Eqs. 267 (2019) 7085–7134]. where the asymptotic stability of this model was investigated. We are able to decompose the region E into three parts where the associated semigroups are analytic, of Gevrey classes of specific order, and non-smoothing, respectively. Moreover, by a detailed spectral analysis, we will show that the orders of Gevrey class are sharp, under proper conditions. We also show that the orders of polynomial stability obtained in Fernández Sare et al. [J. Diff. Eqs. 267 (2019) 7085–7134] are optimal.
Rétro-BIM ou la question de l’intégration : une revue anachronique
Authors: Sattler Léa , Lamouri Samir , Pellerin Robert
Published: November 2020

Si la collaboration digitale autour du BIM est toujours un défi de nos jours, comment cette problématique était-elle traitée dans la période de gestation du BIM, avant les années 2000 ? Le présent article mène une revue de littérature rétroactive sur le sujet, à travers 6 thèmes récurrents (la comparaison avec les industries digitalisées, la conjonction de l’organisationnel et du numérique, le bouleversement des temporalités du projet, les nouveaux modèles de données, les processus dynamiques et l’anticipation), dans le but de donner une perspective historique à cette question actuelle.
Le BIM peut-il être un agent facilitant les démarches de développement durable dans la construction ?
Authors: André Elodie , Boulekbache Hafida , Gallas Mohamed-Anis
Published: November 2020

Le BIM et le développement durable ont connu une evolution parallèle dans des sphères d’acteurs différentes depuis les années 70. Nous étudions les possibilités de croisement entre ces deux thématiques dans une volonté d’envisager le BIM comme agent facilitant des démarches de développement durable auprès des acteurs de la construction.
Numérisation de l'idéation : analyse des méthodes de travail collaboratif instrumenté en conception intégrée
Authors: Baudoux Gaëlle , Calixte Xaviéra , Leclercq Pierre
Published: November 2020

Dans le contexte actuel de la conception architecturale, il s'avère utile de questionner l'instrumentation numérique de l'idéation. Dans cet article, nous étudions les méthodes de travail collaboratif instrumenté au travers des pratiques des concepteurs. En particulier, nous observons les "Moyens de conception", c’est-à-dire les types d'actions de conception mis en oeuvre et leurs articulations, indépendamment des logiciels utilisés. Nous pouvons ainsi mettre en évidence des combinaisons récurrentes de "Moyens", des patterns, témoins de leur complémentarité dans les activités, nous renseignant sur les pratiques et les besoins des concepteurs.
La réalité virtuelle au service de l’apprentissage de la géométrie descriptive : retour vers Monge
Authors: Khamallah Nawri , Pleitinx Renaud , Sgambi Luca
Published: November 2020

Cet article s’intéresse aux avantages pédagogiques de la réalité virtuelle et à son application dans le cas de l’apprentissage de la géométrie descriptive. Il décrit l’implémentation et les premiers résultats d’une application en réalité virtuelle destinée à soutenir l’enseignement de la géométrie descriptive dans la Faculté d’architecture, d’ingénierie architecturale, d’urbanisme de l’UCLouvain.
Synthesis of Pyridiniumboranephosphonate Diesters and Related Compounds using Trityl Cation as a Borane Hydride Acceptor
Authors: Stawinski Jacek , Rachwalak Marta , Gołębiewska Justyna , Jakubowski Tomasz
Published: November 2020

Boranephosphonate diesters react with pyridine and some tertiary amines in the presence of dimethoxytrityl chloride used as a borane­ hydride acceptor, to afford the boron-modified phosphodiester analogues containing a P-B-N structural motif. The reaction provides a convenient entry to pyridinium- and ammoniumboranephosphonates derived from the corresponding alkyl, aryl, or nucleoside boranephosphonate diesters. Some aspects of the synthetic protocol, mechanistic features related to a possible intermediate involved, and the role of the solvents used, are discussed.
Synthesis of Azido Acids and Their Application in the Preparation of Complex Peptides
Authors: Moreira Ryan , Noden Michael , Taylor Scott D.
Published: November 2020

Azido acids are important synthons for the synthesis of complex peptides. As a protecting group, the azide moiety is atom-efficient, easy to install and can be reduced in the presence of many other protecting groups, making it ideal for the synthesis of branched and/or cyclic peptides. α-Azido acids are less bulky than urethane-protected counterparts and react more effectively in coupling reactions of difficult-to-form peptide and ester bonds. Azido acids can also be used to form azoles on complex intermediates. This review covers the synthesis of azido acids and their application to the total synthesis of complex peptide natural products.

1 Introduction

2 Synthesis of α-Azido Acids

2.1 From α-Amino Acids or Esters

2.2 Via α-Substitution

2.3 Via Electrophilic Azidation

2.4 Via Condensation of N-2-Azidoacetyl-4-Phenylthiazolidin- 2-Thi one Enolates with Aldehydes and Acetals

2.5 Synthesis of α,β-Unsaturated α-Azido Acids and Esters

3 Synthesis of β-Azido Acids

3.1 Preparation of Azidoalanine and 3-Azido-2-aminobutanoic Acids

3.2 General Approaches to Preparing β-Azido Acids Other Than Azi doalanine­ and AABA

4 Azido Acids in Total Synthesis

4.1 α-Azido Acids

4.2 β-Azido Acids and Azido Acids Containing an Azide on the Side
Chain

5 Conclusions
7P’s of life-satisfaction: a social constructionist model for the life satisfaction of religious minority groups in Kohat, Khyber Pakhtunkhwa (Pakistan)
Authors: Alam Jan
Published: November 2020

Minority groups can, depending societal conditions, find themselves living marginalized lives in some communities. Religious-based discrimination can result in these groups feeling dejected and deprived of their basic rights, resulting in, among other things, stress and dissatisfaction. To understand and explore their life satisfaction, their plight needs to be addressed. Here, I present the findings from a qualitative study conducted in the Kohat district, involving the selection and interview of 27 participants, comprising 14 Christians, seven Hindus, and six Sikhs. Participants representing three different religious groups were purposively selected and interviewed using a semi-structured interview guide. Participants of the study included religious scholars, social activists, employees, and political representatives from these religious minorities. A thematic approach was used for data analysis, which comprises coding, categories, and thematic coding. The emerged categories were prioritized and then allocated names, each beginning with the letter “P”, under one thematic code namely, the “7P’s of life satisfaction”.
Examining the population flow network in China and its implications for epidemic control based on Baidu migration data
Authors: Wei Sheng , Wang Lei
Published: November 2020

This paper examines the spatial pattern of the population flow network and its implications for containing epidemic spread in China. The hierarchical and spatial subnetwork structure of national population movement networks is analysed by using Baidu migration data before and during the Chinese Spring Festival. The results show that the population flow was mainly concentrated on the east side of the Hu Huanyong Line, a national east-west division of population density. Some local hot spots of migration were formed in various regions. Although there were a large number of migrants in eastern regions, they tended to concentrate in corresponding provincial capital cities and the population movement subnetworks were affected by provincial administrative divisions. The patterns identified are helpful for the provincial government to formulate population policies on epidemic control. The movement flow from Wuhan (the city where the covid-19 outbreak) to other cities is significantly and positively correlated with the number of confirmed cases in other Chinese cities (about 70% of the population was constituted through innerprovincial movement in Hubei). The results show that the population flow network has great significance for informing the containment of the epidemic spread in the early stage. It suggests the importance for the Chinese government to implement provincial and municipal lockdown measures to contain the epidemic spread. The paper indicates that spatial analysis of population flow network has practical implications for controlling epidemic outbreaks.
Noether’s-type theorems on time scales
Authors: Anerot Baptiste , Cresson Jacky , Hariz Belgacem Khaled , Pierret Frederic
Published: November 2020

We prove a time scales version of the Noether theorem relating group of symmetries and conservation laws in the framework of the shifted and nonshifted Δ calculus of variations. Our result extends the continuous version of the Noether theorem as well as the discrete one and corrects a previous statement of Bartosiewicz and Torres [“Noether’s theorem on time scales,” J. Math. Anal. Appl. 342(2), 1220–1226 (2008)]. This result implies also that the second Euler–Lagrange equation on time scales is derived by Bartosiewicz, Martins, and Torres [“The second Euler–Lagrange equation of variational calculus on time scales,” Eur. J. Control 17(1), 9–18 (2011)]. Using the Caputo duality principle introduced by Caputo, [“Time scales: From Nabla calculus to delta calculus and vice versa via duality, Int. J. Differ. Equations 5, 25–40, (2010)], we provide the corresponding Noether theorem on time scales in the framework of the shifted and nonshifted ∇ calculus of variations. All our results are illustrated with numerous examples supported by numerical simulations.
Reduction of divisors for classical superintegrable GL(3) magnetic chain
Authors: Tsiganov A. V.
Published: November 2020

Separated variables for a classical GL(3) magnetic chain are coordinates of a generic positive divisor D of degree n on a genus g non-hyperelliptic algebraic curve. Because n > g, this divisor D has unique representative ρ(D) in the Jacobian, which can be constructed by using dim|D| = n − g steps of Abel’s algorithm. We study the properties of the corresponding chain of divisors and prove that the classical GL(3) magnetic chain is a superintegrable system with dim|D| = 2 superintegrable Hamiltonians.
Plasticizer ethylene carbonate facilitates new ion coordination site in blend polymer electrolyte: Dielectric relaxation through two-parameter Mittag-Leffler function
Authors: Patla Subir Kumar , Roy Choudhury Anupa , Ray Ruma , Das Shantanu , Karmakar Sanat
Published: November 2020

A solid polymer electrolyte (SPE) film with improved mechanical and thermal stability has drawn significant attention in the field of polymer research due to their technological applications in energy storage devices. We have explored the electrical properties of the blend SPE composed of 20 wt. % poly(ethylene oxide), 80 wt. % polyvinylidene fluoride, and 35 wt. % NH4I by introducing a plasticizer ethylene carbonate (EC). A significant enhancement of electrical conductivity has been found in the composite SPE containing 80 wt. % of EC. We have confirmed the formation of a hydrogen bonding network between the carbonyl group (C=O) of EC and the cations NH4+. Therefore, EC facilitates the new coordination sites via the hydrogen bonding network with the cations NH4+, which eventually leads to the enhancement of conductivity up to a maximum value of 1.2 × 10−4 S/cm at 80 wt. % of EC. The increase in the relative percentage of contact ions over free ions at 80% of EC, as estimated from the FTIR study, is thus intriguing. Therefore, we have proposed an ion transport mechanism based on ion hopping through different coordinating sites mediated by EC. Dielectric relaxation of the composite SPE has been best delineated by a two-parameter Mittag-Leffler function. The exponents obtained from the fit of the experimental decay function with the two-parameter Mittag-Leffler function in the entire time domain are positive and less than one, suggesting non-Debye relaxation in the polymer composite system under investigation.
Nanoscale ultrasonic subsurface imaging with atomic force microscopy
Authors: Ma Chengfu , Arnold Walter
Published: November 2020

Imaging of subsurface features down to the nanometer scale is of great importance in various fields such as microelectronics, materials science, nanobiology, and nanomedicine. Since their invention 25 years ago, ultrasonic-based atomic force microscopy (AFM) techniques have attracted vast attention for their mechanical surface and subsurface sensing capability. In this Perspective article, we review the research on ultrasonic AFMs for subsurface imaging. We first describe the instrumentation setups and different detection schemes of ultrasonic AFMs. Then, attention is paid to the studies of the physical contrast mechanism, the evaluation of the detection capabilities, in particular, the detection depth limits, and the optimization approaches to enhance the contrast and to improve the detection depth. After that we present typical applications of using ultrasonic AFMs for detecting subsurface defects including dislocations, voids, and interfaces in functional materials and devices; visualizing embedded inclusions in composites; and imaging subcellular structures in biological materials. We conclude with an outlook of the challenges faced by ultrasonic AFMs toward fast, high resolution, and quantitative subsurface imaging.
Investigation of physically transient resistive switching memory based on GeO2 thin films
Authors: Feng Julin , Hu Wei , Zeng Fanju , Lin Hao , Li Liye , Yang Ben , Peng Yao , Wu Daofu , Huo Benjun , Tang Xiaosheng
Published: November 2020

Physically transient resistive switching memory has attracted much attention in recent years for potential applications in security information storage and environmental protection. Herein, we demonstrated that resistive switching memory composed of Ag/GeO2/fluorine-doped tin oxide structures exhibited remarkable electrical properties and could be rapidly dissolved by de-ionized water. The robust capabilities of the as-fabricated memory with more than 100 enduring cycles, a comparable resistance window larger than the OFF/ON ratio of 102, and a long retention time of more than 10 h was achieved. In addition, the degradable characteristics were demonstrated by the dissolution of amorphous GeO2 thin films in de-ionized water with the disappearance of resistive switching properties. Furthermore, the switching mechanism has been explained by the filament model, and the degradable mechanism of GeO2 films has been investigated by the change of chemical bonds and resistive switching properties in different humidity environments. Our results suggest that GeO2-based resistive switching memory could find opportunities for applications in physically transient electronics.
Compact integrated optical sensors and electromagnetic actuators for vibration isolation systems in the gravitational-wave detector KAGRA
Authors: Akutsu Tomotada , Peña Arellano Fabián Erasmo , Shoda Ayaka , Fujii Yoshinori , Okutomi Koki , Barton Mark Andrew , Takahashi Ryutaro , Komori Kentaro , Aritomi Naoki , Shimoda Tomofumi , Takano Satoru , Takeda Hiroki , Tapia San Martin Enzo Nicolas , Kozu Ryohei , Ikenoue Bungo , Obuchi Yoshiyuki , Fukushima Mitsuhiro , Aso Yoichi , Michimura Yuta , Miyakawa Osamu , Kamiizumi Masahiro
Published: November 2020

This paper reports on the design and characteristics of a compact module integrating an optical displacement sensor and an electromagnetic actuator for use with vibration–isolation systems installed in KAGRA, the 3-km baseline gravitational-wave detector in Japan. In the technical concept, the module belongs to a family tree of similar modules used in other interferometric gravitational-wave detector projects. After the initial test run of KAGRA in 2016, the sensor part, which is a type of slot sensor, was modified by increasing the spacing of the slot from 5 mm to 15 mm to avoid the risk of mechanical interference with the sensor flag. We confirm that the sensor performance is comparable to that of the previous design despite the modification. We also confirm that the sensor noise is consistent with the theoretical noise budget. The noise level is 0.5 nm/Hz1/2 at 1 Hz and 0.1 nm/Hz1/2 at 10 Hz, and the linear range of the sensor is 0.7 mm or more. We measured the response of the actuator to be 1 N/A and also measured the resistances and inductances of coils of the actuators to confirm consistency with theory. Coupling coefficients among the different degrees of freedom were also measured and shown to be negligible, varying little between designs. A potential concern about thermal noise contribution due to eddy current loss is discussed. As of 2020, 42 of the modules are in operation at the site.
Modulation of photoelectric properties of indium tin oxide thin films via oxygen control, and its application to epsilon-near-zero properties for an infrared absorber
Authors: Chai Xin , Zhang Yuzhi , Cao Yunzhen , Wu Lingnan , Ma Jiayu , Liu Yangqiao , Song Lixin
Published: November 2020

Indium tin oxide (ITO) films with tunable epsilon-near-zero (ENZ) properties have attracted great interest among researchers. In this study, ITO films with tunable photoelectric properties were prepared by a magnetron sputtering technique under different oxygen flow rates, and their structures and optical properties are studied. The ENZ wavelength shift and electron accumulation layer were observed from their permittivity and carrier concentrations, which were calculated by a graded model combined with an oscillator model. This demonstrated that the variable carrier concentrations induced the tunable ENZ property of the ITO films. Meanwhile, the interface of the film and the substrate was found to have a significant influence on the loose lower layer by researching the profile of permittivity and carrier concentrations. Furthermore, the simulation of the transfer matrix method indicated that using ENZ materials as substrates can achieve zero reflection at an ENZ wavelength. ITO films serve as absorbers based on this characteristic. An absorption device was fabricated; its largest absorption rate was 97.41% at 1576 nm, and it maintained high absorption over a wide range of incident angles. The absorption mechanism in the ENZ film is illustrated by absorption maps and electric field distribution.
Multiple striking negative differential resistance in a polyyne wire doped with an organometallic fragment
Authors: Guo Yan-Dong , Wang Jin-Jie , Zeng Hong-Li , Ran Yu-Si , Liang Zhao-Chen , Yan Xiao-Hong
Published: November 2020

Inspired by the recent experimental progress on the synthesization of a new type of molecule, a polyyne wire doped with the organometallic Ru(dppe)2 fragment, which exhibits superior electronic properties to similar organic molecules reported before, we studied the electronic transport of it contacted with Au electrodes through first-principles calculations. Multiple striking negative differential resistance (NDR) behavior is observed, where the current could decrease to nearly zero. Moreover, such a phenomenon is found to be robust to the conformational change of the molecule, indicating it is the intrinsic feature of it. Further analysis shows that it is the suppression of the transmission peaks at the border of the bias window that results in the NDR. And, the suppression is resulted from the decay of the local density of states in the two-probe system, especially in the central axis of the molecule, where the states are found to originate from the p orbital of C atoms and the d orbital of Ru atoms. The multiple striking NDR behavior is achieved at the single-molecule level under low bias, showing great application potentials. These findings may throw light on the development of molecular devices.
Temperature dependence of three-dimensional domain wall arrangement in ferroelectric K0.9Na0.1NbO3 epitaxial thin films
Authors: Schmidbauer Martin , Bogula Laura , Wang Bo , Hanke Michael , von Helden Leonard , Ladera Adriana , Wang Jian-Jun , Chen Long-Qing , Schwarzkopf Jutta
Published: November 2020

The three-dimensional arrangement and orientation of domain walls in ferroelectric K0.9Na0.1NbO3/(110)NdScO3 epitaxial thin films were investigated at different temperatures both experimentally by means of piezoresponse force microscopy and three-dimensional x-ray diffraction and theoretically by three-dimensional phase-field simulations. At room temperature, a well-ordered herringbone-like domain pattern appears in which there is a periodic arrangement of a1a2/MC monoclinic phases. Four different types of domain walls are observed, which can be characterized by out-of-plane tilt angles of ±45° and in-plane twist angles of ±21°. For the orthorhombic high-temperature phase, a periodic a1/a2 stripe domain pattern with exclusive in-plane polarization is formed. Here, two different types of domain walls are observed, both of them having a fixed out-of-plane domain wall angle of 90° but distinguished by different in-plane twist angles of ±45°. The experimental results are fully consistent with three-dimensional phase-field simulations using anisotropic misfit strains. The qualitative agreement between the experiment and the theory applies, in particular, to the wide phase transition range between about 180 °C and 260 °C. In this temperature range, a complex interplay of coexisting monoclinic a1a2/MC and orthorhombic a1/a2 phases takes place.
Electric field effect on 31P NMR magnetic shielding
Authors: Shenderovich Ilya G.
Published: November 2020

Magnetic shielding depends on molecular structure and noncovalent interactions. This study shows that it is also measurably dependent on the electric field generated by surrounding molecules. This effect has been observed explicitly for 31P nucleus using the adduct under field approach. The results obtained indicate that the field strength experienced by molecules in crystals consisting of molecules with large dipole moments is similar to that in polar solvents. Therefore, magnetic shielding should explicitly depend on solvent polarity. It is important to note that this effect cannot be reproduced correctly within the polarizable continuum model approach.
Lessons learned from a subsidised spectacles scheme aiming to improve eye health in Aboriginal people in Victoria, Australia
Authors: Fricke Timothy R. , Brand Chelsea , Lovett Levi , Turner Neville W. , Anjou Mitchell D. , Bentley Sharon A.
Published: November 2020

The Victorian Aboriginal Spectacles Subsidy Scheme (VASSS) aimed to improve access to visual aids and eye care for Aboriginal and Torres Strait Islander Victorians. The VASSS started in July 2010 and has operated continually since. In 2016, we explored the collaborations, planning, adaptations and performance of the VASSS over the first 6 years by reviewing and analysing service data, as well as data from semistructured interviews, focus groups and surveys. An estimated 10 853 VASSS cofunded visual aids were delivered over 6 years, and the mean annual number of comprehensive eye examinations provided within services using VASSS grew 4.6-fold faster compared with the 4 years preceding the VASSS. We estimate that 16% and 19% of recipients presented with distance and near vision impairments respectively, all of which were corrected with visual aids. VASSS achievements were attained through collaborations, flexibility, trust and communication between organisations, all facilitated by funding resulting from evidence-based advocacy. Access to visual aids and eye examinations by Aboriginal Victorians has improved during the operation of the VASSS, with associated direct and indirect benefits to Aboriginal health, productivity and quality of life. The success of the VASSS may be replicable in other jurisdictions and provides lessons that may be applicable in other fields. What is known about the topic? The 2009 National Indigenous Eye Health Survey estimated that the age-adjusted prevalence of vision impairment was 2.8-fold higher and the prevalence of blindness 6.2-fold higher among adult Aboriginal Australians compared with non-Aboriginal Australians, predominantly due to uncorrected refractive error and cataract. What does this paper add? Implemented in 2010, the Victorian Aboriginal Spectacles Subsidy Scheme (VASSS) has been supported, designed and well received by stakeholders and, critically, the Aboriginal community. The VASSS has successfully improved access to comprehensive eye examinations and high-quality affordable visual aids (principally spectacles, with cost certainty). What are the implications for practitioners? The VASSS demonstrates the power of collaborative partnerships and the potential for solutions targeted at specific components of a system to generate wider benefits, including the reduction of the prevalence and burden of vision impairment by correcting refractive error, managing vision-threatening eye disease and increasing awareness of eye health issues.
Wildfire dynamics and impacts on a tropical Andean oak forest
Authors: Aguilar-Garavito Mauricio , Isaacs-Cubides Paola , Ruiz-Santacruz J. Sebastian , Cortina-Segarra Jordi
Published: November 2020

Wildfires have increasingly damaged Andean tropical forests. However, both a poor understanding of wildfire dynamics and ecosystem response limits awareness about the magnitude of the problem and design management strategies. We estimate the impacts and significant drivers of wildfires by dating and mapping recent wildfires in an Andean tropical forest area, the Iguaque mountains. A large part of Iguaque hosts a population of the only Quercus species in South America, Quercus humboldtii. We used remote-sensing, official reports and social mapping to reconstruct the recent history of wildfires and change in oak forest patches in Iguaque. Between 1990 and 2017, 25 wildfires were recorded, with fire intervals between 4 and 21 years. These events burned 28.4% of the Iguaque mountains and showed a significant increasing trend in extent. Wildfires mostly occurred in the south, during the driest months, and their number and extent showed substantial interannual variations related to El Niño–Southern Oscillation cycles. Wildfires contributed to a 45% reduction in oak forests along with the fragmentation of existing populations. Our study presents evidence of the extent and impact of wildfires in Iguaque and provides new insights on fire dynamics in Andean tropical forests.
Infant imitation in a third-party context
Authors: Stenberg Gunilla
Published: November 2020

The present study examined 17-month-olds’ imitation in a third-party context. In four experiments, the infants watched while a reliable or an unreliable model demonstrated a novel action with an unfamiliar (Experiments 1 and 3) or a familiar (Experiments 2 and 4) object to another adult. In Experiments 3 and 4, the second adult imitated the model’s novel action. Neither the familiarity of the object or whether or not the second adult copied the model’s behavior influenced the likelihood of infant imitation. Findings showed that the infants in the reliable model condition were more willing to imitate the model’s action with the unfamiliar object. The results suggest that infants take into account the reliability of a model even when the model has not directly demonstrated her reliability to the infant.
Improvement of spin polarization spatial uniformity in optically pumped atomic magnetometers based on counter-propagating pump beams and atomic diffusion
Authors: Zhao Junpeng , Liu Gang , Lu Jixi , Ding Ming , Ma Yanning , Ji Jie , Yang Ke , Ma Danyue , Xing Bozheng , Zhang Ning , Sun Chang , Han Bangcheng
Published: November 2020

In an optically pumped alkali vapor cell with a high density of atoms, the attenuation of the pump light generates a spatially non-uniform distribution of the electronic spin polarization of alkali atoms, which is detrimental to biomagnetism applications of magnetometers as well as the hyperpolarization of noble gas atoms. Therefore, in this study, we propose a new scheme to generate a nearly uniform, unsaturated spin polarization region based on counter-propagating pump beams and atomic diffusion. A finite element method-based simulation is used to demonstrate the three-dimensional distribution of the spin polarization in a spherical cell. The effects of cell temperature and pump light power on the homogeneity of the spin polarization are studied. The distribution of spin polarization near the center of the cell is experimentally measured and a 1 cm uniform spin polarization region is achieved in the center of the cell. The uniformity of spin polarization in the center region of the cell increased by 50% compared with single beam pumping. The advantage of our proposed scheme is that it can generate an unsaturated uniform region of spin polarization in the center of a cell using a single species of alkali atoms.