bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping polymer donors with a non-fused acceptor possessing outward branched alkyl chains for efficient organic solar cells
Authors: Shen Qing , He Chengliang , Li Shuixing , Zuo Lijian , Shi Minmin , Chen Hongzheng
Published: January 2023

A fully non-fused electron acceptor BO-4T with condensed π–π stacking and obvious face-on orientation was developed. The D:A pairing principles for NFREA-based OSCs were explored and PM6 works the best with BO-4T.
Chloride-doping, defect and interlayer engineering of copper sulfide for superior sodium-ion batteries
Authors: Pan Zhonghao , Zhang Xianghua , Xu Shitan , Gu Mingzheng , Rui Xianhong , Zhang Xiaojun
Published: January 2023

A flower-like copper sulfide anode with NH4+ interlayer intercalation, chloride-doping and rich vacancy defects is developed for sodium-ion batteries, demonstrating high reversible capacity and excellent rate capability.
ZIF-8 integrated with polydopamine coating as a novel nano-platform for skin-specific drug delivery
Authors: Wang Qiuyue , Li Mingming , Sun Xinxing , Chen Naiying , Yao Sicheng , Feng Xun , Chen Yang
Published: January 2023

A kind of nanoparticular system based on zeolitic imidazolate framework-8 (ZIF-8) and polydopamine (PDA) modification was developed for improving the dermal delivery of 5-fluorouracil (5-FU).
Recent advances in the development of phenothiazine and its fluorescent derivatives for optoelectronic applications
Authors: Khan Faizal , Misra Rajneesh
Published: January 2023

Phenothiazine is one of the most extensively investigated aromatic compounds owing to its unique optical and electronic properties. This review highlighted the recent advances in the development of phenothiazine-based fluorescent materials for applications in various fields.
Visible-light-induced organophotocatalytic and singlet oxygen-initiated domino construction of 1,4-dihydropyridines, C-3 functionalized spiro[indoline-3,4′-pyridines] and C-11 functionalized spiro[indeno-[1,2-b]quinoxaline-11,4′-pyridines]
Authors: Borah Biplob , Patat Mihir , Singh Vipin , Sivaprakash Murugesan , Prasad Madavi S. , Chowhan L. Raju
Published: January 2023

Highly efficient synthesis of functionalized 1,4-dihydropyridines, spiro[indoline-3,4′-pyridines], and spiro[indeno[1,2-b]quinoxaline-11,4′-pyridines] using rose Bengal photocatalyst under blue LED in an aqueous medium at rt has been disclosed.
Correction: Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3via scanning diamond magnetic probe microscopy
Authors: Erickson Adam , Abbas Shah Syed Qamar , Mahmood Ather , Fescenko Ilja , Timalsina Rupak , Binek Christian , Laraoui Abdelghani
Published: January 2023

Correction for ‘Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3via scanning diamond magnetic probe microscopy’ by Adam Erickson et al., RSC Adv., 2023, 13, 178–185, https://doi.org/10.1039/D2RA06440E
Considerations in Utilizing Translanguaging Practices to Meet the Language Needs of Maya Children in U.S. Schools
Authors: Hernández Amalia W. , Campos Iván , Zyskind Karen Zuniga
Published: January 2023

Purpose:

Meeting the needs of Maya children in U.S. schools requires extensive training. Research is lacking in best practices to support students with intersectional identities. This article provides a roadmap centralized on Maya children's experiences, acknowledging the linguistic diversity of Maya immigrants, their language and cultural practices, and their integration into or exclusion from minoritized and White neighborhoods in the United States to provide a starting point for culturally responsive service delivery.

Conclusions:

Supporting the needs of Maya children requires an approach that values and recognizes their intersectional identities while developing collaborative relationships with students, families, and educators. Application of the roadmap will support to (a) identify educational obstacles faced by Maya children, (b) integrate translanguaging to support best practices for educational success, and (c) determine service delivery considerations for bilingual/trilingual, multicultural children. More research on the topic is needed to establish evidence-based practice guidelines to utilize a translanguaging pedagogy within speech-language pathology.
Enhanced diversity scheme for orthogonal frequency division multiplexing systems over doubly selective fading channels
Authors: Xie Yuelei , Li Wenshan , Wan Jie , Ouyang Shan
Published: January 2023

Frequency‐time selective fading degrades the performance of communication systems, but it also provides an opportunity to collect multipath diversity and Doppler diversity. In this paper, an oversampled grouped‐linear‐constellation‐precoding (GLCP) scheme is proposed for orthogonal frequency division multiplexing (OFDM) systems to extract the diversity inherent in doubly selective fading channels. In the proposed scheme, GLCP is employed to precode the information symbols of OFDM at the transmitter, and the precoded OFDM symbols are oversampled in the time domain at the receiver. A full‐groups maximum likelihood (ML) decoder and a successive group decoder to decode the oversampled OFDM symbols with diversity gains are developed. The successive group decoder combines the group ML decoding algorithm with a block‐decision‐feedback‐equalization (BDFE) algorithm. The proposed scheme can take advantage of both the GLCP scheme and the oversampling scheme to achieve multipath diversity gains and Doppler diversity gains in doubly selective fading channels. Simulation results show that the proposed scheme can significantly improve the performance of OFDM systems in the frequency selective fading channel and the doubly selective fading channel in terms of bit error ratio, indicating that the diversity gains can be greatly enhanced by the proposed scheme in doubly selective fading channels.
Sub-kiloparsec empirical relations and excitation conditions of HCN and HCO+ J = 3–2 in nearby star-forming galaxies
Authors: García-Rodríguez A. , Usero A. , Leroy A. K. , Bigiel F. , Jiménez-Donaire M. J. , Liu D. , Querejeta M. , Saito T. , Schinnerer E. , Barnes A. , Belfiore F. , Bešlić I. , Cao Y. , Chevance M. , Dale D. A. , den Brok J. S. , Eibensteiner C. , García-Burillo S. , Glover S. C. O. , Klessen R. S. , Pety J. , Puschnig J. , Rosolowsky E. , Sandstrom K. , Sormani M. C. , Teng Y.-H. , Williams T. G.
Published: January 2023

We present new HCN and HCO+ (J = 3–2) images of the nearby star-forming galaxies (SFGs) NGC 3351, NGC 3627, and NGC 4321. The observations, obtained with the Morita ALMA Compact Array, have a spatial resolution of ∼290–440 pc and resolve the inner Rgal ≲ 0.6–1 kpc of the targets, as well as the southern bar end of NGC 3627. We complement this data set with publicly available images of lower excitation lines of HCN, HCO+, and CO and analyse the behaviour of a representative set of line ratios: HCN(3–2)/HCN(1–0), HCN(3–2)/HCO+(3–2), HCN(1–0)/CO(2–1), and HCN(3–2)/CO(2–1). Most of these ratios peak at the galaxy centres and decrease outwards. We compare the HCN and HCO+ observations with a grid of one-phase, non-local thermodynamic equilibrium (non-LTE) radiative transfer models and find them compatible with models that predict subthermally excited and optically thick lines. We study the systematic variations of the line ratios across the targets as a function of the stellar surface density (Σstar), the intensity-weighted CO(2–1) (⟨ICO⟩), and the star formation rate surface density (ΣSFR). We find no apparent correlation with ΣSFR, but positive correlations with the other two parameters, which are stronger in the case of ⟨ICO⟩. The HCN/CO–⟨ICO⟩ relations show ≲0.3 dex galaxy-to-galaxy offsets, with HCN(3–2)/CO(2–1)–⟨ICO⟩ being ∼2 times steeper than HCN(1–0)/CO(2–1). In contrast, the HCN(3–2)/HCN(1–0)–⟨ICO⟩ relation exhibits a tighter alignment between galaxies. We conclude that the overall behaviour of the line ratios cannot be ascribed to variations in a single excitation parameter (e.g., density or temperature).
Computing the gravitational potential on nested meshes using the convolution method
Authors: Vorobyov Eduard I. , McKevitt James , Kulikov Igor , Elbakyan Vardan
Published: January 2023

Aims. Our aim is to derive a fast and accurate method for computing the gravitational potential of astrophysical objects with high contrasts in density, for which nested or adaptive meshes are required.

Methods. We present an extension of the convolution method for computing the gravitational potential to the nested Cartesian grids. The method makes use of the convolution theorem to compute the gravitational potential using its integral form.

Results. A comparison of our method with the iterative outside-in conjugate gradient and generalized minimal residual methods for solving the Poisson equation using nonspherically symmetric density configurations has shown a comparable performance in terms of the errors relative to the analytic solutions. However, the convolution method is characterized by several advantages and outperforms the considered iterative methods by factors 10–200 in terms of the runtime, especially when graphics processor units are utilized. The convolution method also shows an overall second-order convergence, except for the errors at the grid interfaces where the convergence is linear.

Conclusions. High computational speed and ease in implementation can make the convolution method a preferred choice when using a large number of nested grids. The convolution method, however, becomes more computationally costly if the dipole moments of tightly spaced gravitating objects are to be considered at coarser grids.
High-mass eclipsing binaries: A testbed for models of interior structure and evolution
Authors: Pavlovski K. , Southworth J. , Tkachenko A. , Van Reeth T. , Tamajo E.
Published: January 2023

Aims. The surface chemical compositions of stars are affected by physical processes that bring the products of thermonuclear burning to the surface. Despite their potential in helping us understand the structure and evolution of stars, elemental abundances are available for only a few high-mass binary stars. We aim to enlarge this sample by determining the physical properties and photospheric abundances for four eclipsing binary systems that contain high-mass stars: V1034 Sco, GL Car, V573 Car, and V346 Cen. The components have masses of 8–17 M⊙, have effective temperatures from 22 500 to 32 200 K, and are all on the main sequence.

Methods. We present new high-resolution and high signal-to-noise spectroscopy from the High Accuracy Radial velocity Planet Searcher (HARPS), which we analysed using spectral disentangling and non-local thermodynamic equilibrium spectral synthesis. We modelled existing light curves and new photometry from the Transiting Exoplanet Survey Satellite (TESS).

Results. We measure the stellar masses to a 0.6–2.0% precision, radii to a 0.8–1.7% precision, effective temperatures to a 1.1–1.6% precision, and abundances of C, N, O, Mg, and Si. The abundances are similar to those found in our previous studies of high-mass eclipsing binaries; our sample now comprises 25 high-mass stars in 13 binary systems. We also find tidally excited pulsations in V346 Cen.

Conclusions. These results reinforce our previous conclusions: interior chemical element transport is not as efficient in binary star components as in their single-star counterparts in the same mass regime and evolutionary stage, possibly due to the effects of tidal forces. Our ultimate goal is to provide a larger sample of OB-type stars in binaries to enable a thorough comparison to stellar evolutionary models, as well as to single high-mass stars.
Modeling Solar Orbiter dust detection rates in the inner heliosphere as a Poisson process
Authors: Kočiščák S. , Kvammen A. , Mann I. , Sørbye S. H. , Theodorsen A. , Zaslavsky A.
Published: January 2023

Context.Solar Orbiter provides dust detection capability in the inner heliosphere, but estimating physical properties of detected dust from the collected data is far from straightforward.

Aims.First, a physical model for dust collection considering a Poisson process is formulated. Second, it is shown that dust on hyperbolic orbits is responsible for the majority of dust detections with Solar Orbiter’s Radio and Plasma Waves (RPW). Third, the model for dust counts is fitted to Solar Orbiter RPW data and parameters of the dust are inferred, namely radial velocity, hyperbolic meteoroids predominance, and the solar radiation pressure to gravity ratio as well as the uncertainties of these.

Methods.Nonparametric model fitting was used to get the difference between the inbound and outbound detection rate and dust radial velocity was thus estimated. A hierarchical Bayesian model was formulated and applied to available Solar Orbiter RPW data. The model uses the methodology of integrated nested Laplace approximation, estimating parameters of dust and their ncertainties.

Results.Solar Orbiter RPW dust observations can be modeled as a Poisson process in a Bayesian framework and observations up to this date are consistent with the hyperbolic dust model with an additional background component. Analysis suggests a radial velocity of the hyperbolic component around (63 ± 7) km s−1with the predominance of hyperbolic dust being about (78 ± 4)%. The results are consistent with hyperbolic meteoroids originating between 0.02 AU and 0.1 AU and showing substantial deceleration, which implies effective solar radiation pressure to a gravity ratio ≳ 0.5. The flux of the hyperbolic component at 1 AU is found to be (1.1 ± 0.2) × 10−4m−2s−1and the flux of the background component at 1 AU is found to be (5.4 ± 1.5) × 10−5m−2s−1.
Pulmonary Findings in Hospitalized COVID-19 Patients Assessed by Lung Ultrasonography (LUS) – A Prospective Registry Study
Authors: Barner Anna , Burian Egon , Simon Alexander , Castillo Katty , Waschulzik Birgit , Braren Rickmer , Heemann Uwe , Osterwalder Joseph , Spiel Alexander , Heim Markus , Stock Konrad Friedrich
Published: January 2023

Purpose This prospective two-centre study investigated
localisation-dependent lesion patterns in COVID-19 with standard lung ultrasonography (LUS)
and their relationship with thoracic computed tomography (CT) and clinical parameters.

Materials and Methods Between April 2020 and April 2021, 52 SARS-CoV-2-positive
patients in two hospitals were examined by means of LUS for “B-lines”, fragmented
pleura, consolidation and air bronchogram in 12 lung regions and for pleural effusions. A
newly developed LUS score based on the number of features present was correlated with clinical
parameters (respiration, laboratory parameters) and the CT and analysed with respect to the
30- and 60-day outcome. All patients were offered an outpatient LUS follow-up.

Results The LUS and CT showed a bilateral, partially posteriorly
accentuated lesion distribution pattern. 294/323 (91%) of CT-detected lesions were pleural.
The LUS score showed an association with respiratory status and C-reactive protein; the
correlation with the CT score was weak (Spearman’s rho = 0.339, p < 0.001). High LUS scores
on admission were also observed in patients who were discharged within 30 days. LUS during
follow-up showed predominantly declining LUS scores.

Conclusion The LUS score reflected the clinical condition of the
patients. No conclusion could be made on the prognostic value of the LUS, because of the low
event rate. The LUS and CT score showed no sufficient correlation. This is probably due to
different physical principles, which is why LUS could be of complementary value.
Factors influencing compliance of closed fishing season: lessons from small-scale coastal fisheries in the Central Region of Ghana
Authors: Owusu Victor , Adu-Boahen Kofi , Kyeremeh Sender , Demalie Innocent , Eshun Philip
Published: January 2023

This paper contributes to the literature on marine conservation and its implication for coastal governance and sustainability. The study investigates factors influencing fisherfolk compliance with the temporal fishing bans in Ghana. The purpose is to understand the factors influencing compliance behaviour to help design an improved conservation strategy to achieve management objectives. A mixed-method approach was employed, consisting of 200 household surveys and 17 in-depth interviews with stakeholders at the local, district, regional, and national levels. The results reveal that a combination of instrumental and normative factors influences fisherfolk’s compliance behaviour concerning the closed fishing season. Participation of fisherfolk and coastal communities in the fisheries management decision-making processes positively influenced compliance. The key drivers of non-compliance with the closed season emanate from a perceived lack of ecological effectiveness, lack of enforcement of sanctions, and lack of compensation for loss of income during the ban. The study suggests co-management that includes fisheries agencies and traditional authorities as a viable option for fisheries management and marine conservation initiatives. In addition, the paper recommends the introduction of conservation payment schemes alongside strict monitoring of the temporal ban on fishing.
Lithiation-induced conductivity modulation in Prussian blue interlayer for stable Li/garnet solid-state batteries
Authors: Zhang Bo , Zhang Yang , Hu Jiulin , Lei Meng , Shen Zong-Yang , Li Chilin
Published: January 2023

The garnet-based solid-state batteries have the potential advantages of high energy density and safety. However, the poor solid–solid contact and Li dendrite growth at the anode interface lead to uneven Li deposition or short circuit, which hinders their practical application. Here, we propose a Prussian blue (PB) interlayer to improve the interface contact and charge transfer between Li anode and garnet electrolyte by lithiation-induced conductivity modulation. This mixed-conducting interlayer with unique 3D open framework enables a well welded interface with enhanced lithiophilicity and uniform Li diffusion. The Li/garnet interface resistance is significantly reduced. This lithiated PB interlayer is highly durable with invariable thickness during cycling, leading to a highly stable cycling of Li plating/stripping and corresponding LiFePO4 full cells without dendrite growth. The dual modulation of ion and electron transports in an integrated structure without phase segregation through thermal or electrochemical lithiation provides a solution to the challenge of solid–solid interfaces and the development of practical solid-state batteries.
Phonon polarization deformation in graphene induced by substrate coupling strengths
Authors: Chang Yu-Chen , Das Bipul , Chiang Yu-Fan , Chang Wen-Hao , Chen Yen-Chun , Kesarwani Rahul , Ke Wen-Cheng , Lan Yann-Wen , Lu Ting-Hua
Published: January 2023

Displacement in the Raman shift of conventional Raman spectroscopy usually includes an increase in the number of material layers or a strain variation. To distinguish them, polarization-resolved Raman spectroscopy provides an additional degree of freedom to resolve it. In this work, strained graphene induced by different substrates on G band and 2D band phonon modes is studied by polarization-resolved Raman spectroscopy and verified by numerical analysis using Raman tensors and optical Jones calculus. For the strained graphene case, polarization properties of scattered light are obviously different from that in the case of unstrained graphene. Deformation of phonon polarization is seen to originate from different strengths of substrate coupling. This research provides an efficient quantitative method to explore any distortion of strain anisotropy in two-dimensional materials, which is important for the development of straintronics in the future.
Dynamical classic limit: Dissipative vs conservative systems
Authors: Gonzalez Acosta G. , Plastino A. , Kowalski A. M.
Published: January 2023

We analyze the nonlinear dynamics of a quartic semiclassical system able to describe the interaction of matter with a field. We do it in both dissipative and conservative scenarios. In particular, we study the classical limit of both frameworks and compare the associated features. In the two environments, we heavily use a system’s invariant, related to the Uncertainty Principle, that helps to determine how the dynamics tends to the pertinent classical limit. We exhibit the convergence to the classical limit and also verify that the Uncertainty Principle is complied with during the entire process, even in the presence of dissipation.
Optical properties of plasmonic tunneling junctions
Authors: Tang Yuankai , Harutyunyan Hayk
Published: January 2023

Over the last century, quantum theories have revolutionized our understanding of material properties. One of the most striking quantum phenomena occurring in heterogeneous media is the quantum tunneling effect, where carriers can tunnel through potential barriers even if the barrier height exceeds the carrier energy. Interestingly, the tunneling process can be accompanied by the absorption or emission of light. In most tunneling junctions made of noble metal electrodes, these optical phenomena are governed by plasmonic modes, i.e., light-driven collective oscillations of surface electrons. In the emission process, plasmon excitation via inelastic tunneling electrons can improve the efficiency of photon generation, resulting in bright nanoscale optical sources. On the other hand, the incident light can affect the tunneling behavior of plasmonic junctions as well, leading to phenomena such as optical rectification and induced photocurrent. Thus, plasmonic tunneling junctions provide a rich platform for investigating light–matter interactions, paving the way for various applications, including nanoscale light sources, sensors, and chemical reactors. In this paper, we will introduce recent research progress and promising applications based on plasmonic tunneling junctions.
Direct evidence for weak ferromagnetism sustained by Fe2+–O–Fe3+ superexchange coupling in short-range structures of aluminosilicate glasses
Authors: Jucá R. F. , Soares J. M. , Soares V. A. , Evaristo D. S. , Oliveira F. G. S. , Vasconcelos I. F. , Saraiva G. D. , Ferreira N. S. , Macêdo M. A.
Published: January 2023

We report on the magnetism of amorphous SiO2–Al2O3–CaO–MgO–Fe2O3–K2O–MnO:CA (CA—activated carbon) aluminosilicate glasses prepared by a fusion-quenching method. Fourier transform infrared and Raman spectroscopy show that a Fe2+ lattice modifier in the glass structures induces depolymerization, strongly influencing the magnetic transitions. Room temperature magnetization measurements of the CA-glasses show a different magnetic behavior, such as speromagnetism, asperomagnetism, and weak ferromagnetism. Mössbauer spectroscopy analyses at room temperature reveal that iron changes valence from Fe3+ → Fe2+ with increasing CA content. This Fe3+ → Fe2+ suggests that asperomagnetism and weak ferromagnetism behavior are triggered by Fe2+–O–Fe3+ superexchange coupling in short-range structures of aluminosilicate glasses. A model for the aluminosilicate glass structures is proposed to explain the different magnetic regimes.
Deterministic multi-level spin orbit torque switching using focused He+ ion beam irradiation
Authors: Kurian Jinu , Joseph Aleena , Cherifi-Hertel Salia , Fowley Ciaran , Hlawacek Gregor , Dunne Peter , Romeo Michelangelo , Atcheson Gwenaël , Coey J. M. D. , Doudin Bernard
Published: January 2023

He+ ion irradiation is used to pattern multiple areas of Pt/Co/W films with different irradiation doses in Hall bars. The resulting perpendicular magnetic anisotropy landscape enables selective multilevel current-induced switching with full deterministic control of the position and order of the individual switching elements. Key pattern design parameters are specified, opening a way to scalable multi-level switching devices.
Density functional approach to elastic properties of three-dimensional dipole-spring models for magnetic gels
Authors: Goh Segun , Menzel Andreas M. , Wittmann René , Löwen Hartmut
Published: January 2023

Magnetic gels are composite materials consisting of a polymer matrix and embedded magnetic particles. Those are mechanically coupled to each other, giving rise to the magnetostrictive effects as well as to a controllable overall elasticity responsive to external magnetic fields. Due to their inherent composite and thereby multiscale nature, a theoretical framework bridging different levels of description is indispensable for understanding the magnetomechanical properties of magnetic gels. In this study, we extend a recently developed density functional approach from two spatial dimensions to more realistic three-dimensional systems. Along these lines, we connect a mesoscopic characterization resolving the discrete structure of the magnetic particles to macroscopic continuum parameters of magnetic gels. In particular, we incorporate the long-range nature of the magnetic dipole–dipole interaction and consider the approximate incompressibility of the embedding media and relative rotations with respect to an external magnetic field breaking rotational symmetry. We then probe the shape of the model system in its reference state, confirming the dependence of magnetostrictive effects on the configuration of the magnetic particles and on the shape of the considered sample. Moreover, calculating the elastic and rotational coefficients on the basis of our mesoscopic approach, we examine how the macroscopic types of behavior are related to the mesoscopic properties. Implications for real systems of random particle configurations are also discussed.
Micro-/macroscopic and density functional studies of the interactions between molybdenum trioxide and C60 molecule
Authors: Nakaya Masato , Kawai Takuya , Watanabe Shinta , Onoe Jun
Published: January 2023

We have investigated the interactions between C60 and (MoO3)n using scanning tunneling microscopy with spectroscopy (STM/STS) and ex situ ultraviolet–visible–near-infrared (UV–vis–NIR) spectroscopy in combination with density functional theory (DFT) calculations. The formation of (MoO3)n chemically bound to C60 is energetically favorable due to ΔG < 0 for n = 1, 2, 4, 6, 8, and 9, and they well reproduced the histogram of the height of (MoO3)n on the C60 (111) terrace obtained by a STM height-profile. STS results demonstrated the upward energy shift of both highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of C60 in the vicinity of (MoO3)n (n = 6 or 9), which is consistent with the previous results of the co-deposited C60/MoO3 film obtained using photoemission and inverse photoemission spectroscopy [Wang and Gao, Appl. Phys. Lett. 105, 111601 (2014), Yang et al., J. Phys.: Condens. Matter 28, 185502 (2016), and Li et al., J. Phys. Chem. C 118, 4869 (2014)]. Theoretical calculations of (MoO3)n (n = 1, 2, 4, 6, 8, and 9) chemically bound to C60 indicated that 0.01–0.32 holes are injected into C60 by (MoO3)n nanoclusters, and UV–vis–NIR and DFT results found that the hole doping to C60 is caused via the electron transfer from the HOMO of C60 to the LUMO of (MoO3)n. Furthermore, it is noted that the C60–(MoO3)n interactions exhibit a high heat resistance up to 250 °C by examining the UV–vis–NIR spectra of a co-deposited C60/MoO3 (6:4) film before and after thermal annealing. The present findings provide useful information for the practical use of P-type C60-based thermoelectric devices.
Radial growth rate of near-critical crystal nuclei in poly(l-lactic acid) (PLLA) in Tammann’s two-stage development method
Authors: Andrianov Ruslan A. , Schmelzer Jürn W. P. , Androsch René , Mukhametzyanov Timur A. , Schick Christoph
Published: January 2023

The specific features of crystal nucleation widely determine the morphology of the evolving crystalline material. Crystal nucleation is, as a rule, not accessible by direct observation of the nuclei, which develop with time. This limitation is caused by the small size (nanometer scale) of the critical nuclei and the stochastic nature of their formation. We describe an experimental approach to the determination of specific features of the cluster size distribution employing fast scanning calorimetry at scanning rates up to 10 000 K s−1. The surviving cluster fraction is determined by selectively melting/dissolving clusters smaller than the critical size corresponding to the highest temperature of a short spike positioned between the nucleation and the development stage in Tammann’s two-stage method. This approach allows for estimating the time evolution of the radius of the largest detectable clusters in the distribution. Knowing this radius as a function of nucleation time allows for determining a radial growth rate. In the example of poly(l-lactic acid) (PLLA), the order of magnitude estimate of radial growth rates of clusters of about 2–5 nm yields values between 10−5 and 10−3 nm s−1. The radial growth rate of micrometer-sized spherulites is available from optical microscopy. The corresponding values are about three orders of magnitude higher than the values for the nanometer-sized clusters. This difference is explainable by stochastic effects, transient features, and the size dependence of the growth processes on the nanometer scale. The experimental and (order of magnitude) classical nucleation theory estimates agree well.
Fast crystallization below the glass transition temperature in hyperquenched systems
Authors: Lucas Pierre , Takeda Wataru , Pries Julian , Benke-Jacob Julia , Wuttig Matthias
Published: January 2023

Many phase change materials (PCMs) are found to crystallize without exhibiting a glass transition endotherm upon reheating. In this paper, we review experimental evidence revealing that these PCMs and likely other hyperquenched molecular and metallic systems can crystallize from the glassy state when reheated at a standard rate. Among these evidences, PCMs annealed below the glass transition temperature Tg exhibit slower crystallization kinetics despite an increase in the number of sub-critical nuclei that should promote the crystallization speed. Flash calorimetry uncovers the glass transition endotherm hidden by crystallization and reveals a distinct change in kinetics when crystallization switches from the glassy to the supercooled liquid state. The resulting Tg value also rationalizes the presence of the pre-Tg relaxation exotherm ubiquitous of hyperquenched systems. Finally, the shift in crystallization temperature during annealing exhibits a non-exponential decay that is characteristic of structural relaxation in the glass. Modeling using a modified Turnbull equation for nucleation rate supports the existence of sub-Tg fast crystallization and emphasizes the benefit of a fragile-to-strong transition for PCM applications due to a reduction in crystallization at low temperature (improved data retention) and increasing its speed at high temperature (faster computing).
Trilobite tridents demonstrate sexual combat at 400 Mya
Authors: Gishlick Alan D. , Fortey Richard A.
Published: January 2023

The Devonian trilobiteWalliseropscarries a remarkable anterior cephalic trident posing a challenge to functional interpretation. A unique teratological specimen ofWalliserops trifurcatusshowing four, rather than three tines, is inconsistent with possible hypotheses connecting the trident to feeding techniques and suggests a sexually selected function. Malformations in a variety of living organisms support this conclusion. Morphometric comparisons to similar structures used for intraspecific combat in dynastine beetles show that the trident occupies a comparable shape space consistent with the hypothesis that it was a sexual combat weapon, the oldest reported example of its kind. This lends further credibility to the idea that some trilobites may have been strongly sexually dimorphic.
Regulator of Awn Elongation 3
, an E3 ubiquitin ligase, is responsible for loss of awns during African rice domestication
Authors: Bessho-Uehara Kanako , Masuda Kengo , Wang Diane R. , Angeles-Shim Rosalyn B. , Obara Keisuke , Nagai Keisuke , Murase Riri , Aoki Shin-ichiro , Furuta Tomoyuki , Miura Kotaro , Wu Jianzhong , Yamagata Yoshiyuki , Yasui Hideshi , Kantar Michael B. , Yoshimura Atsushi , Kamura Takumi , McCouch Susan R. , Ashikari Motoyuki
Published: January 2023

Two species of rice have been independently domesticated from different ancestral wild species in Asia and Africa. Comparison of mutations that underlie phenotypic and physiological alterations associated with domestication traits in these species gives insights into the domestication history of rice in both regions. Asian cultivated rice,
Oryza sativa,
and African cultivated rice,
Oryza glaberrima
, have been modified and improved for common traits beneficial for humans, including erect plant architecture, nonshattering seeds, nonpigmented pericarp, and lack of awns. Independent mutations in orthologous genes associated with these traits have been documented in the two cultivated species. Contrary to this prevailing model, selection for awnlessness targeted different genes in
O. sativa
and
O. glaberrima
. We identify
Regulator of Awn Elongation 3
(
RAE3
) a gene that encodes an E3 ubiquitin ligase and is responsible for the awnless phenotype only in
O. glaberrima
. A 48-bp deletion may disrupt the substrate recognition domain in
RAE3
and diminish awn elongation. Sequencing analysis demonstrated low nucleotide diversity in a ~600-kb region around the derived
rae3
allele on chromosome 6 in
O. glaberrima
compared with its wild progenitor. Identification of
RAE3
sheds light on the molecular mechanism underlying awn development and provides an example of how selection on different genes can confer the same domestication phenotype in Asian and African rice.
Soft, malleable double diamond twin
Authors: Feng Xueyan , Dimitriyev Michael S. , Thomas Edwin L.
Published: January 2023

A twin boundary (TB) is a common low energy planar defect in crystals including those with the atomic diamond structure (C, Si, Ge, etc.). We study twins in a self-assembled soft matter block copolymer (BCP) supramolecular crystal having the
double
diamond (DD) structure, consisting of two translationally shifted, interpenetrating diamond networks of the minority polydimethyl siloxane block embedded in a polystyrene block matrix. The coherent, low energy, mirror-symmetric double tubular network twin has one minority block network with its nodes offset from the (222) TB plane, while nodes of the second network lie in the plane of the boundary. The offset network, although at a scale about a factor of 10
3
larger, has precisely the same geometry and symmetry as a (111) twin in atomic single diamond where the tetrahedral units spanning the TB retain nearly the same strut (bond) lengths and strut (bond) angles as in the normal unit cell. In DD, the second network undergoes a dramatic restructuring—the tetrahedral nodes transform into two new types of mirror-symmetric nodes (pentahedral and trihedral) which alternate and link to form a hexagonal mesh in the plane of the TB. The collective reorganization of the supramolecular packing highlights the hierarchical structure of ordered BCP phases and emphasizes the remarkable malleability of soft matter.
Long-term core–mantle interaction explains W-He isotope heterogeneities
Authors: Ferrick Amy L. , Korenaga Jun
Published: January 2023

The isotopic characteristics of ocean island basalts have long been used to infer the nature of their source and the long-term evolution of the Earth’s mantle. Anticorrelation between tungsten and helium isotopic signatures is a particularly puzzling feature in those basalts, which no single process appears to explain. Traditionally, the high
3
He/
4
He signature has been attributed to an undegassed reservoir in the deep mantle. Additional processes needed to obtain low
182
W/
184
W often entail unobserved ancillary geochemical effects. It has been suggested, however, that the core feeds the lower mantle with primordial helium, obviating the need for an undegassed mantle reservoir. Independently, the tungsten-rich core has been suggested to impart the plume source with anomalous tungsten isotope signatures. We advance the idea that isotopic diffusion may simultaneously transport both tungsten and helium across the core–mantle boundary, with the striking implication that diffusion can naturally account for the observed isotopic trend. By modeling the long-term isotopic evolution of mantle domains, we demonstrate that this mechanism can account for more than sufficient isotopic ratios in plume-source material, which, after dynamical transport to the Earth’s surface, are consistent with the present-day mantle W-He isotopic heterogeneities. No undegassed mantle reservoir is required, bearing significance on early Earth conditions such as the extent of magma oceans.
The ASH1–PEX16 regulatory pathway controls peroxisome biogenesis for appressorium-mediated insect infection by a fungal pathogen
Authors: Wang Lili , Lai Yiling , Chen Jingjing , Cao Xuan , Zheng Weilu , Dong Ling , Zheng Yitong , Li Fang , Wei Gang , Wang Sibao
Published: January 2023

Entomopathogenic fungi infect insects by penetrating through the cuticle into the host body. To breach the host cuticle, some fungal pathogens produce specialized infection cells called appressoria, which develop enormous turgor pressure to allow cuticle penetration. However, regulatory mechanisms underlying appressorium turgor generation are poorly understood. Here, we show that the histone lysine methyltransferase ASH1 in the insecticidal fungus
Metarhizium robertsii
, which is strongly induced during infection of the mosquito cuticle, regulates appressorium turgor generation and cuticle penetration by activating the peroxin gene
Mrpex16
via H3K36 dimethylation. MrPEX16 is required for the biogenesis of peroxisomes that participate in lipid catabolism and further promotes the hydrolysis of triacylglycerols stored in lipid droplets to produce glycerol for turgor generation, facilitating appressorium-mediated insect infection. Together, the ASH1–PEX16 pathway plays a pivotal role in regulating peroxisome biogenesis to promote lipolysis for appressorium turgor generation, providing insights into the molecular mechanisms underlying fungal pathogenesis.
Do children help dogs spontaneously?
Authors: Reddy Rachna B. , Echelbarger Margaret , Toomajian Natalie , Hammond Taeah , Wellman Henry M.
Published: January 2023

Two capacities considered foundational in human cooperation are prosocial motivation and goal-reading abilities that enable helping. Children exhibit both proclivities by age 2 in interactions with other humans, but interactions with nonhuman species on whom we have been interdependent for millennia are unstudied. We tested the hypothesis that children’s goal-reading and prosocial propensities extend to other animals. We predicted children would help pet dogs access objects that dogs attempted to reach but could not reach themselves. We studied 97 children between 2 and 3 years of age living in a small mid-western US city, 44 of whom had dogs as household pets. In a quasi-naturalistic setting, we introduced children to 1 of 3 friendly pet dogs who remained within a small, porous enclosure while a treat or toy was placed outside it. Dogs reacted naturally, either showing interest in accessing the item (e.g., pawing, begging) or ignoring it. Measures of dog and child behavior during sessions were coded blindly with high reliability. Children provided dogs with out-of-reach items twice as often when dogs showed interest rather than ignored items, indicating sensitivity to the dog’s goals. Additionally, children were more generally likely to provide dogs with items if children lived with pet dogs, if dogs were more lively and engaged rather than subdued and if the item was a treat rather than a toy. These findings lend support to our hypothesis that children’s early-developing proclivities for goal-reading and prosociality extend beyond humans to other animals.
The impact of hydrogen plasma on the structure and morphology of tin and lead micrometer sized particles
Authors: Shefer D , Nikipelov A , van de Kerkhof M , Marvi Z , Banine V , Beckers J
Published: January 2023

The stability of micrometer sized particles in hydrogen plasma is essential for extreme ultraviolet lithography, the ITER fusion program and the application of hydrogen plasma etching. We experimentally investigated the morphological evolution of tin (Sn), lead (Pb), and lead (II) oxide (PbO) micrometer sized particles on a surface that is exposed to a low pressure hydrogen plasma. Post exposure particle cross sections obtained by a scanning electron microscope accompanied by a focused ion beam demonstrated a significant influence of hydrogen plasma exposure on both the surface and the bulk material of the particles. Chemical sputtering at the surface and accumulation of pressurized hydrogen bubbles in cavities in the bulk material are the main drivers of the morphological changes. These mechanisms may influence the adhesion of particles to the surface through the introduction of asperities, increase of contact spot area, or fragmentation after the accumulation of mechanical stress.
Research on flame temperature measurement method based on water vapor emission spectrum
Authors: Zhou Gongxi , Li Fei , Lin Xin , Li Renjie , Meng Dongdong , Yu Xilong
Published: January 2023

Internal temperature monitoring of high-speed propulsion systems is highly important for engine performance evaluation and lifetime prediction. As a passive optical measurement method without the need for an external light source and without flow field interference, the emission spectrum measurement technique has good application prospects for harsh measurement environments. As the main combustion product, high-temperature water vapor shows a strong emission intensity that is highly suitable for temperature measurement applications. We propose use of the band integral ratio to remove the high resolution measurement requirements for the spectrum acquisition system. In addition, the temperatures of methane-oxygen flames with different equivalent ratios are measured successfully under the condition that the influence of self-absorption on the measurements is considered.
Improving discharge performance of space-charge limited hot cathodes via local neutral collisionality
Authors: Yip Chi-Shung , Jin Chenyao , Zhang Wei , Jiang Di , Xu Guo Sheng
Published: January 2023

The effects of neutral gas inlet location to the performance of SCL hot cathodes is investigated. It is found that placing the neutral gas inlet very close (∼5 mm) to the hot cathode can significantly improve the emission characteristics via immersing the hot cathode in a volume of elevated neutral density. Such placement of the neutral gas inlet was found to make no observable effect on global plasma parameters when the discharge conditions are otherwise identical, facilitating the implementation of this measure onto existing plasma devices. Even with only a small part of the hot cathode is immersed in a volume of an elevated neutral density, the improvement of electron emission is found to be very significant. Thus, one can envision a design of a hot cathode assembly with an integrated neutral gas inlet to significantly improve its emission performance. The underlying mechanism of this improvement of hot cathode performance is the reduction of SCL effects, thus applicable to SCL hot cathodes regardless of heating configurations. This will be particularly useful in low pressure applications where a widened range of operable plasma parameters are often desirable.
The anomalous shift of the weak boson mass and the quintessence electroweak axion
Authors: Lin Weikang , Yanagida Tsutomu T , Yokozaki Norimi
Published: January 2023

One of the simplest ways to account for the observed W-boson mass shift is to introduce the SU(2)
L
triplet Higgs boson with zero hypercharge, whose vacuum expectation value is about 3 GeV. If the triplet is heavy enough at


(
1
)

TeV, it essentially contributes only to T parameter without any conflict with the observation. The presence of a complex triplet Higgs boson raises the SU(2)
L
gauge coupling constant to α
2(M
PL) ≃ 1/44 at the Planck scale. Thanks to this larger gauge coupling constant, we show that the electroweak axion vacuum energy explains the observed cosmological constant provided that the axion field is located near the hill top of the potential at present.
Phase-field-crystal simulation of nano-single crystal microcrack propagation under different orientation angles
Authors: Peng Dunwei , Zhang Yunpeng , Tian Xiaolin , Hou Hua , Zhao Yuhong
Published: January 2023

The propagation mechanism of microcracks in nanocrystalline single crystal systems under uniaxial dynamic and static tension is investigated using the phase-field-crystal method. Both dynamic and static stretching results show that different orientation angles can induce the crack propagation mode, microscopic morphology, the free energy, crack area change, and causing fracture failure. Crack propagation mode depends on the dislocation activity near the crack tip. Brittle propagation of the crack occurs due to dislocation always at crack tip. Dislocation is emitted at the front end of the crack tip and plastic deformation occurs, which belongs to ductile propagation. The orientation angles of 9° and 14° are brittle--ductile mixed propagation, while the orientation angles of 19° and 30° are brittle propagation and no dislocation is formed under dynamic tension. The vacancy and vacancy connectivity phenomenon would appear when the orientation angle is 14° under static tension, and the crack would be ductile propagation. While the orientation angle is 19° and 30°, the crack propagates in a certain direction, which is a kind of brittle propagation. This work has some practical significance in preventing material fracture failure and improving material performance.
Spectral tracking of proton beams by the Timepix3 detector with GaAs, CdTe and Si sensors
Authors: Novak A. , Granja C. , Sagatova A. , Zach V. , Stursa J. , Oancea C.
Published: January 2023

Position and directional-sensitive spectrometry of energetic charged particles can be performed with high resolution and wide dynamic range (energy, direction) with the hybrid semiconductor pixel detectors Timepix/Timepix3. The choice of semiconductor sensor material, thickness, and properties such as the reverse bias voltage, greatly determine detector sensitivity and resolving power for spectrometry and particle tracking. We investigated and evaluated the spectral tracking resolving power such as deposited energy and linear-energy-transfer (LET) spectra with the Timepix3 detector with different semiconductor sensors, based on GaAs:Cr, CdTe, and Si, using well-defined radiation sources in terms of radiation type (protons), energy, and incident direction to the detector sensor. Measurements of particle incident direction in a wide range were performed with collimated monoenergetic proton beams of various energies in the range 8–31 MeV at the U120-M cyclotron at the NPI CAS Rez near Prague. All detectors were per-pixel calibrated. This work enables to examine and perform a detailed study of charge sharing and charge collection efficiency in semiconductor sensors. The results serve to optimise the detector chip-sensor assembly configuration for measurements especially with high-LET particles in ion radiotherapy and outer space. The work underway includes evaluation of newly refined semi-insulating GaAs sensors and improved radiation hard semiconductor sensors SiC.