bluuebunny/crossref_metadata_2025 huggingface dataset:
Early sleep after action observation and motor imagery training boosts improvements in manual dexterity
Authors: Temporiti Federico , Calcagno Alessandra , Coelli Stefania , Marino Giorgia , Gatti Roberto , Bianchi Anna Maria , Galli Manuela
Published: February 2023

The systematic observation and imagination of actions promotes acquisition of motor skills. Furthermore, studies demonstrated that early sleep after practice enhances motor learning through an offline stabilization process. Here, we investigated behavioral effects and neurodynamical correlates of early sleep after action observation and motor imagery training (AO + MI-training) on motor learning in terms of manual dexterity. Forty-five healthy participants were randomized into three groups receiving a 3 week intervention consisting of AO + MI-training immediately before sleeping or AO + MI-training at least 12 h before sleeping or a control stimulation. AO + MI-training implied the observation and motor imagery of transitive manual dexterity tasks, whereas the control stimulation consisted of landscape video-clips observation. Manual dexterity was assessed using functional tests, kinematic and neurophysiological outcomes before and after the training and at 1-month follow-up. AO + MI-training improved manual dexterity, but subjects performing AO + MI-training followed by early sleep had significantly larger improvements than those undergoing the same training at least 12 h before sleeping. Behavioral findings were supported by neurodynamical correlates during motor performance and additional sleep-dependent benefits were also detected at 1 month follow-up. These findings introduce a new approach to enhance the acquisition of new motor skills or facilitate recovery in patients with motor impairments.
Modulating the electronic properties of divalent lanthanoid complexes with subtle ligand tuning
Authors: Hay Moya A. , Gable Robert W. , Boskovic Colette
Published: February 2023

A structural, photophysical and electrochemical investigation of complexes [LnII(Mentpa)2]2+ (Ln = Eu, Yb; n = 0, 2 and 3) reveals how the steric requirements of the ligands modulate the LnII ligand field and the resulting electronic properties.
Effective regulation on catalytic performance of nickel–iron–vanadium layered double hydroxide for urea oxidationviasulfur incorporation
Authors: Peng Kai , Liu Liyan , Bhuvanendran Narayanamoorthy , Qiao Fen , Lei Guangping , Lee Sae Youn , Xu Qian , Su Huaneng
Published: February 2023

The S-NiFeV LDH catalyst exhibits exceptional catalytic activity and stability toward the urea oxidation reactionviaa sulfur-doping strategy.
EtOH/H2O ratio modulation on carbon for high-Voc (1.03 V) printable mesoscopic perovskite solar cells without any passivation
Authors: Sheng Jie , Zhu Xiaotian , Xu Xiaoli , He Jingshan , Ma Dun , Liu Jialing , Wu Wenjun
Published: February 2023

Based on an improved Stöber strategy, a phenol-formaldehyde resin-based carbon was developed for p-MPSCs. With optimum ratio of EtOH and H2O, the open-circuit voltage (Voc) increases from 0.97 V to 1.03 V with a maximum PCE of 17.64%.
Synthesis of thiodisaccharides related to 4-thiolactose. Specific structural modifications increase the inhibitory activity against E. coli β-galactosidase
Authors: Dada Lucas , Colomer Juan Pablo , Manzano Verónica E. , Varela Oscar
Published: February 2023

Benzyl β-d-Gal-S-(1→4)-3-deoxy-4-thio-α-d-hexopyranosides were synthesized as inhibitors of E. coli β-galactosidase. The inhibitory activity can be markedly increased by introducing structural modifications in the benzyl 4-thiohexopyranoside moiety.
A ratiometric fluorescent probe for fast detection and bioimaging of formaldehyde
Authors: Lin Nai-Jie , Wu Huan , Peng Jing , Yang Shu-Han , Tan Rui , Peng Yu , Wang Ya-Wen
Published: February 2023

A novel ratiometric fluorescent probe has been developed for rapid detection of formaldehyde based on a new recognition mechanism.
One-step synthesis of polycyclic thianthrenes from unfunctionalized aromatics by thia-APEX reactions
Authors: Kawahara Kou P. , Ito Hideto , Itami Kenichiro
Published: February 2023

In this paper, thia-APEX reactions affording π-extended thianthrene derivatives from unfunctionalized aromatics are described.
LLPSvs.LLCPS: analogies and differences
Authors: Azzari Paride , Mezzenga Raffaele
Published: February 2023

We compare the process of Liquid–Liquid Phase Separation (LLPS) of flexible macromolecules, with the Liquid–Liquid Crystalline Phase Separation (LLCPS) of rigid fibrils, which involves the formation of a liquid phase with a directional alignment.
Cu–Co bimetallic nanocluster Mott–Schottky interaction increasing oxygen reduction reaction activity in rechargeable Zn-air batteries
Authors: Dong Qing , Wang Haoran , Liu Fangfang , Ren Jianwei , Wang Hui , Wang Xuyun , Wang Rongfang
Published: February 2023

The Mott–Schottky effect between Cu nanoclusters and Co nanoclusters on 3D nitrogen-doped porous carbon nanosheet frameworks enhances the catalytic activity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER).
Byproduct formation in heterogeneous catalytic ozonation processes
Authors: Wu Tingting
Published: February 2023

Heterogeneous catalytic ozonation (HCO) is a promising advanced oxidation process (AOP) that can effectively degrade recalcitrant organic pollutants; but formation of harmful byproducts should be carefully evaluated.
Functionalized nickel(ii)–iron(ii) dithiolates as biomimetic models of [NiFe]-H2ases
Authors: Song Li-Cheng , Wang Yin-Peng , Dong Yi-Xiong , Yang Xi-Yue
Published: February 2023

The syntheses, structures and chemical reactivity of a series of new butterfly NiIIFeII(μ-S)2 core-containing [NiFe]-H2ase models have been investigated.
A Li–F co-doped g-C3N4/TiO2-B(001) heterostructure as an efficient hydrogen evolution photocatalyst
Authors: Yuan Xiaojia , Tang Shuhan , Liu Xiaojie
Published: February 2023

Li–F co-doping enhances the interfacial interaction of the Li@g-C3N4/F@TiO2-B(001) heterostructure, which has the lowest HER overpotential, promotes the separation of electron–hole pairs, and improves the photocatalytic performance.
Everyday Barriers in Communicative Participation According to People With Communication Problems
Authors: ter Wal Nicole , van Ewijk Lizet , Dijkhuis Lotti , Visser-Meily Johanna M. A. , Terwee Caroline B. , Gerrits Ellen
Published: February 2023

Purpose:

The purpose of this study was to gain a comprehensive understanding of participation situations that are challenging for people with communication problems, to provide input for the further development of potential items for the Communicative Participation Item Bank (CPIB).

Method:

A purposive sampling strategy was used to include a diverse group of people with communication problems. Diaries were used as a sensitizing exercise for inductive in-depth interviews. In these interviews, elements of communicative participation situations (concepts) were elicited that participants themselves experienced as difficult because of their communication problem. A thematic content analysis was used to identify overarching themes. In addition, new items were formulated based on the raw codes of the transcripts and linked to the International Classification of Functioning, Disability and Health Activity and Participation domains to examine the distribution of items across the breadth of the construct of communicative participation.

Results:

Eighteen interviews yielded 44 different concepts. They were clustered in six themes, which capture the person, location, topic, mode, moment, and pace of communication. In total, 103 new items measuring communicative participation were formulated. Most of these items relate to International Classification of Functioning, Disability and Health Activity and Participation domains “interpersonal interactions and relationships,” “major life areas,” and “community, social, and civic life.”

Conclusions:

This study resulted in an overview of self-reported barriers in daily communicative participation experienced by people with communication problems. These communicative participation situations can be captured within 44 concepts, which are covered by six themes. Future work should investigate if the newly written items can be added to the CPIB. The concepts and the themes can be used in designing and delivering a participation-focused intervention for this population.
Temporal variation of the photometric magnetic activity for the Sun andKeplersolar-like stars
Authors: Santos A. R. G. , Mathur S. , García R. A. , Broomhall A.-M. , Egeland R. , Jiménez A. , Godoy-Rivera D. , Breton S. N. , Claytor Z. R. , Metcalfe T. S. , Cunha M. S. , Amard L.
Published: February 2023

Context.The photometric time series of solar-like stars can exhibit rotational modulation, that is, brightness variations due to active regions co-rotating with the stellar surface. These signatures allow us to constrain properties of stellar rotation and magnetic activity.

Aims.In this work we investigate the behavior, particularly the variability in terms of strength, of the photometric magnetic activity ofKeplersolar-like stars and compare it with that of the Sun.

Methods.We adopted the photometric magnetic activity proxy,Sph, which was computed with a cadence of five times the rotation period (Prot). The averageSphwas taken as the mean activity level, and the standard deviation was taken as a measure of the temporal variation of the magnetic activity over theKeplerobservations. We also analyzed Sun-as-a-star photometric data from VIRGO (Variability of Solar Irradiance and Gravity Oscillations). Sun-like stars were selected from a very narrow parameter space around the solar properties, according to the recentGaia-Keplerstellar properties catalog and the latestKeplerrotation catalog. We also looked into KIC 8006161 (HD 173701), a very active metal-rich G dwarf, and we compared its magnetic activity to that of stars with similar stellar fundamental parameters.

Results.We find that the amplitude ofSphvariability is strongly correlated with its mean value, independent of spectral type. An equivalent relationship has previously been found for ground-based observations of chromospheric activity emission and magnetic field strength, but in this work we show that photometricKeplerdata also present the same behavior. While, depending on the phase of the cycle, the Sun is among the less active stars, we find that theSph⊙properties are consistent with those observed inKeplerSun-like stars. KIC 8006161 is, however, among the most active of its peers, which tend to be metal-rich. This results from an underlying relationship betweenProtand metallicity and supports the following interpretation of the magnetic activity of KIC 8006161: its strong activity is a consequence of its high metallicity, which affects the depth of the convection zone and, consequently, the efficiency of the dynamo.
Detection of magnetic fields in the circumgalactic medium of nearby galaxies using Faraday rotation
Authors: Heesen V. , O’Sullivan S. P. , Brüggen M. , Basu A. , Beck R. , Seta A. , Carretti E. , Krause M. G. H. , Haverkorn M. , Hutschenreuter S. , Bracco A. , Stein M. , Bomans D. J. , Dettmar R.-J. , Chyży K. T. , Heald G. H. , Paladino R. , Horellou C.
Published: February 2023

Context. The existence of magnetic fields in the circumgalactic medium (CGM) is largely unconstrained. Their detection is important as magnetic fields can have a significant impact on the evolution of the CGM, and, in turn, the fields can serve as tracers for dynamical processes in the CGM.

Aims. Using the Faraday rotation of polarised background sources, we aim to detect a possible excess of the rotation measure in the surrounding area of nearby galaxies.

Methods. We used 2461 residual rotation measures (RRMs) observed with the LOw Frequency ARray (LOFAR), where the foreground contribution from the Milky Way is subtracted. The RRMs were then studied around a subset of 183 nearby galaxies that was selected by apparent B-band magnitude.

Results. We find that, in general, the RRMs show no significant excess for small impact parameters (i.e., the perpendicular distance to the line of sight). However, if we only consider galaxies at higher inclination angles and sightlines that pass close to the minor axis of the galaxies, we find significant excess at impact parameters of less than 100 kpc. The excess in |RRM| is 3.7 rad m−2 with an uncertainty between ±0.9 rad m−2 and ±1.3 rad m−2 depending on the statistical properties of the background (2.8σ–4.1σ). With electron densities of ∼10−4 cm−3, this suggests magnetic field strengths of a few tenths of a microgauss.

Conclusions. Our results suggest a slow decrease in the magnetic field strength with distance from the galactic disc, as expected if the CGM is magnetised by galactic winds and outflows.
A history of quantum entanglement and Bell’s inequality
Authors: Żukowski Marek
Published: February 2023

Quantum mechanics gives probabilistic predictions, it is very abstract, and leads to paradoxes. It was discovered in 1925 in two acts of ingenious creativity. By Heisenberg, at the Helgoland island, and by Schrödinger half a year later in Alps. It allows to explain and predict an enormous range of phenomena, but almost immediately met an opposition. Einstein fully recognized it as a practical tool, but criticized its non-deterministic nature. The Einstein-Bohr debate began. Clauser, Aspect and Zeilinger ended it.
Quantum non-locality: from denigration to the nobel prize, via quantum cryptography
Authors: Gisin Nicolas
Published: February 2023

In the late 1960s, a young physicist was sailing along the coast of California towards Berkeley, where he got a post-doc position in astronomy. But his real goal was not astronomy, at least not immediately. First, John Clauser eagerly wanted to test some predictions of quantum theory that were at odds with a then recent and mostly ignored result by an Irish physicist John Stewart Bell, working at the celebrated CERN near Geneva.
Étude comparative de l’infestation de l’anguille européenne Anguilla anguilla par Anguillicoloïdes crassus dans deux biotopes de salinité différente
Authors: Tahri M.
Published: February 2023

Depuis au moins le début des années 1980, l’abondance continentale de l’anguille européenne a décliné à travers toute son aire de répartition, les causes avancées sont très nombreuses vues la complexité de son cycle biologique. Parmi les différentes menaces, nous citons les parasites qui détériorent l’état général du poisson l’empêchant ainsi de retourner sur son lieu de naissance pour boucler son cycle de reproduction et donc met en danger la pérennité de l’espèce. L’objectif premier de ce travail est de comparer l’infestation parasitaire par le nématode Anguillicoloïdes crassus des anguilles vivant dans 2 biotopes de salinité différente : le lac Oubeïra (eau douce) et la lagune Mellah (eau salée) (extrême Nord-Est de l’Algérie). Les taux d’infestation des anguilles capturées au cours des 3 années de suivi avoisinent les 4 % dans la lagune alors qu’ils sont 16 fois plus élevés dans le lac. En ce qui concerne les signes d’inflammation, toutes les anguilles du lac montrent des œdèmes et exsudats de cet organe alors que celles capturées au niveau de la lagune sont indemnes. Ces résultats nous permettent de conclure que la salinité est un facteur – sans doute déterminant – pour la survie de ce parasite et nous mène à proposer d’utiliser le sel comme moyen naturel pour le contrôle de cette parasitose.
Strong error analysis of Euler methods for overdamped generalized Langevin equations with fractional noise: Nonlinear case
Authors: Dai Xinjie , Hong Jialin , Sheng Derui , Zhou Tau
Published: February 2023

This paper considers the strong error analysis of the Euler and fast Euler methods for nonlinear overdamped generalized Langevin equations driven by the fractional noise. The main difficulty lies in handling the interaction between the fractional Brownian motion and the singular kernel, which is overcome by means of the Malliavin calculus and fine estimates of several multiple singular integrals. Consequently, these two methods are proved to be strongly convergent with order nearly min{2(H + α − 1), α}, where H ∈ (1/2, 1) and α ∈ (1 − H, 1) respectively characterize the singularity levels of fractional noises and singular kernels in the underlying equation. This result improves the existing convergence order H + α − 1 of Euler methods for the nonlinear case, and gives a positive answer to the open problem raised in Fang and Li [ESAIM Math. Model. Numer. Anal. 54 (2020) 431–463]. As an application of the theoretical findings, we further investigate the complexity of the multilevel Monte Carlo simulation based on the fast Euler method, which turns out to behave better performance than the standard Monte Carlo simulation when computing the expectation of functionals of the considered equation. Finally, numerical experiments are carried out to support the theoretical results.
Minimizing the number of edges in (Pk ∪ K3)-saturated connected graphs
Authors: Li Yuying , Xu Kexiang
Published: February 2023

For a graph H, a graph G is H-saturated if it contains no copy of H as a (not necessarily induced) subgraph, but the addition of any edge missing from G creates a copy of H in the resultant graph. The connected saturation number sat′(n, H) is defined as the minimum number of edges in H-saturated connected graphs on n vertices. In this paper we consider the (Pk ∪ K3)-saturated connected graphs on n vertices and focus on the determination of sat′(n, Pk ∪ K3). We prove that n + 2 ≤ sat′(n, Pk ∪ K3) ≤ n + 3k-6/2 for n > 3k+4/2 with k ≥ 4 and characterize the extremal graphs at which the upper bounds are attained. Moreover, the exact values of sat′(n, Pk ∪ K3) are determined with k ∈ {3, 4} and we get sat(n, P2 ∪ K3) = sat′(n, P2 ∪ K3) = n.
Triche et signalement sur Strava : analyse des stratégies discursives et des positionnements énonciatifs à l’œuvre dans le contrôle de la performance sportive
Authors: Petrault Jade , Longhi Julien , Duteil Carine , Richard Arnaud
Published: February 2023

Strava, application mobile et réseau social sportif, est dédiée à l’entraînement des coureurs à pied et des cyclistes. Mais Strava est aussi un réseau où l’on peut partager ses courses et entraînements, se comparer aux autres membres, réagir à leurs performances en délivrant des kudos (félicitations / coups de pouce), laisser des commentaires. La meilleure façon de comparer ses performances est de concourir sur des segments (portions de route ou de sentier créées par des membres et validées par l’application). En l’absence d’un regard tiers, des organisateurs de courses ou du public notamment, des phénomènes de triche apparaissent, ce qui peut provoquer un sentiment de méfiance. Ce sentiment conduit même des sportifs à suspecter, signaler ou dénoncer aux autres des cas de tricherie. Notre étude s’articule autour de deux approches complémentaires, l’une pragmatique et l’autre relevant de l’analyse sémantique du discours. Nous nous intéressons aux actes de langage repérables dans les énoncés dénonciateurs, de manière directe ou indirecte, et tout particulièrement à l’intentionnalité des énonciateurs. Cette analyse nous conduit également à étudier l’ethos, autrement dit l’image que l’énonciateur souhaite donner et renvoie de lui-même à travers sa prise de parole (figures de justicier, de dénonciateur, de moralisateur ou de nettoyeur).
Resilienz und Beratung im Gesundheitswesen
Authors: Greiner Wolfgang
Published: February 2023

Im Januar 2023 wurde das jüngste Gutachten des Sachverständigenrates
(SVR) für die Begutachtung der Entwicklung im Gesundheitswesen
übergeben. Die sieben Mitglieder des Rates, darunter drei Ökonomen,
drei Mediziner und eine Pflegewissenschaftlerin, haben sich darin auf etwa 600
Seiten intensiv mit der Resilienz des deutschen Gesundheitswesens auseinandergesetzt
(abrufbar unter www.svr-gesundheit.de). Angesichts von Personalengpässen,
Pandemie, sichtbaren Folgen des Klimawandels sowie offensichtlich zunehmend
anfälligen Lieferketten lautet der Titel des Gutachtens „Resilienz
im Gesundheitswesen - Wege zur Bewältigung zukünftiger
Krisen“. Darin wurde herausgearbeitet, inwieweit das Gesundheitswesen sowohl
insgesamt als auch in einzelnen Sektoren auf zukünftige Krisen vorbereitet
ist und welche Veränderungen zur besseren Vorbereitung auf
zukünftige Krisen erforderlich sind. Zentral ist dabei, wie schon in vorigen
Gutachten die Feststellung, dass weniger ein Erkenntnisdefizit besteht, sondern die
Probleme vor allem im Bereich der Datenverfügbarkeit und Umsetzung
liegen.
New High-Performance Fluorescent Dye Scaffolds: Applications for Bioimaging and Biosensing
Authors: Lei Zuhai , Cheng Junfeng
Published: February 2023

Fluorescence imaging in the shortwave infrared region (SWIR, 850–2500 nm) window has become an indispensable tool in biomedical research because it has weaker absorption, less light scattering, and less background fluorescence in this window. As we know, the design and synthesis of fluorescent dyes and fluorescent probes are the cores of fluorescence imaging and biosensing. Thus, their photophysical mechanisms exploring and bioanalytical applications are multidisciplinary and cutting-edge research topics. In this regard, we have been working on high-performance fluorescent dyes and fluorescent probes for years. In short, we have developed a series of bright, stable, aggregation-resistant, SWIR fluorescent dyes ECXs, based on a carbon-bridged spiro ring strategy. We also developed a series of high-performance SWIR fluorescent dyes CXs and Chrodols, which combine the structural advantages of cyanine and xanthenoid dyes. Based on these new SWIR scaffolds, we further constructed some activatable SWIR fluorescent probes with OFF-ON or ratiometric properties for biosensing in vivo. Therefore, the main line of our work is to gain an in-depth understanding of the photophysical mechanisms of fluorescent dyes, to create high-performance luminescent dyes, and to further develop fluorescent probes for bioimaging and biosensing.

1 Introduction

2 ECX Dyes Based on a Carbon-Bridged Spiro Ring Strategy

3 Fluorescent Dyes and Fluorescent probes Combining the Structures of Cyanine and Xanthenoid Dyes

3.1 CX Series Dyes

3.2 A Functionalized Modified CX probe NRh

3.3 CX-like Dyes with a Secondary Amino Py-2

3.4 Chrodol Series Dyes

4 Conclusion and Future Prospects
Taming Challenging Radical-Based Convergent Paired Electrolysis with Dual-Transition-Metal Catalysis
Authors: Fu Niankai , Li Liubo
Published: February 2023

The past few years have witnessed a renaissance of electrochemistry in organic synthesis. This green technology replaces chemical oxidants or reductants with inexpensive electricity. Paired electrolysis refers to processes in which reactions at both electrodes are desirable. These maximize the energy economy by avoiding the waste of electrical power on sacrificial reactions. Convergent paired electrolysis is a special case in which reactive intermediates are generated simultaneously at both electrodes and then coupled. However, radical-based reactions of this type remain underexploited. The incorporation of transition-metal catalysis could be beneficial by modulating the formation and utilization of highly reactive radical species. In this article, we introduce our most recent successful implementations of this strategic design.

1 Introduction

2 Ce/Ni Dual-Catalytic Decarboxylative Arylation

3 Fe/Ni Dual-Catalytic Esterification of Aryl Halides

4 Conclusion.
Management of Sternal Wound Infection—Determinants of Length of Stay and Recurrence of Infection after Muscle Flap Coverage
Authors: Feller Kathrin , Schipper Lukas , Liu Juan , Phan Truong Quang Vu , Kroeger Knut , Joeckel Karl-Heinz , Lax Hildegard
Published: February 2023

Aim The aim of this study was to define determinants of length of hospital stay (LOS) longer than mean and recurrence of infection (ROI) after complete healing of patients with deep sternal wound infections (DSWI).

Patients and Methods In this observational study, we included 303 patients (155 females and 148 males, with mean age of 68 years) treated from 2016 to 2020 at the Department of Plastic Surgery of the HELIOS Klinik Krefeld, Germany. All patients received extensive necrosectomy, repetitive negative pressure therapy periods, and final transplantation of a pectoral musculocutaneous flap. In the German diagnosis-related group (DRG)-system, the mean inpatient LOS depends on the number of surgical procedures and is longer in those with four or more surgical procedures (DRG IO2B) and shorter in those with fewer procedures (DRGs I02C and I02D). The determinants which have a significant effect on LOS longer than mean and ROI after complete healing were identified by estimating a logistic regression model. The effect of the different calculated determinants was quantified as odds ratio. To measure the discriminant ability of the model between patients, we determined a receiver operating characteristic curve. The fit of the model was quantified by comparing predicted probabilities of the model with empirical probabilities of the data. The goodness of fit was then measured by applying the Hosmer–Lemeshow test.

Results Among patients in DRG IO2B (n = 246), the variable clopidogrel and therapeutic anticoagulation was the most important determinant for a longer LOS, with an odds ratio of 5.83 (95% CI = 0.83/40.80). Female sex and renal insufficiency also prolonged LOS. Applying this analysis to the patients with group DRG groups I02C and I02D (n = 57), none of these parameters were predictive. The variable immunosuppression was the most important determinant for ROI (n = 49) (OR = 4.67; 95% CI = 1.01/21.52). Body mass index also played a role, but with a much smaller influence.

Conclusion There are specific risk factors for LOS longer than mean and ROI in patients with DSWI that can be identified on admission. Addressing these risk factors, if possible, could reduce the rate of patients with LOS longer than mean and ROI.
Mean-variance investing with factor tilting
Authors: Boido Claudio , Fasano Antonio
Published: February 2023

Factor analysis proposes an alternative approach to standard portfolio theory: the latter is optimisation based, while the former is estimation based. Also, in standard portfolio theory, returns are only explained by the portfolio volatility factor, while factor analysis proposes a multiplicity of factors, which the managers can choose from to tilt their portfolios. In attempting to reconcile these alternative worlds, we propose a penalised utility function, incorporating both the Markowitzian risk-return trade-off and the manager’s preferences towards factors, and discriminating among losses and gains relative to a reference asset. The penalisation affects the optimisation process, favouring the selection of portfolios with less variance and more tilted towards the chosen risk factors. Penalty levels set by the manager generalise the traditional notion of risk aversion. We test our model by building an investment portfolio based on a combination of asset classes and selected investing factors, focussed on the eurozone. To identify the optimal portfolio, we adopt a set of three metaheuristic optimisation algorithms: the fitness function stochastic maximization using genetic algorithms, differential evolution algorithm for global optimisation, and the particle swarm optimisation, and dynamically choose the best solution. In this way, we can improve the Markowitzian optimisation by tilting the asset allocation with managers’ expectations and desired exposures towards designated factors.
Additive engineering for highly efficient and stable perovskite solar cells
Authors: Lee Do-Kyoung , Park Nam-Gyu
Published: February 2023

Since the groundbreaking report on solid-state perovskite solar cells (PSCs) in 2012, PSC receives great attention due to its high power conversion efficiency (PCE) obtainable at low-cost fabrication. A PCE of 9.7% in 2012 was swiftly improved to 25.7% in 2022 via perovskite composition engineering and grain size control. The excellent photovoltaic performance originates from the defect-tolerant property of organic lead halide perovskite associated with the antibonding nature of the valence band. Nevertheless, the reduction of defect-induced trap density of the state is still required to improve further photovoltaic performance and stability. Among the methods reported to reduce defects, additive engineering is one of the promising strategies for controlling crystallographic defects because it can regulate crystallization kinetics and grain boundaries. In this review, we describe materials and methods for additive engineering applied to lead-based perovskite. In addition, the effects of additive engineering on photovoltaic performance and stability are discussed.
Benchmarking energy consumption and latency for neuromorphic computing in condensed matter and particle physics
Authors: Kösters Dominique J. , Kortman Bryan A. , Boybat Irem , Ferro Elena , Dolas Sagar , Ruiz de Austri Roberto , Kwisthout Johan , Hilgenkamp Hans , Rasing Theo , Riel Heike , Sebastian Abu , Caron Sascha , Mentink Johan H.
Published: February 2023

The massive use of artificial neural networks (ANNs), increasingly popular in many areas of scientific computing, rapidly increases the energy consumption of modern high-performance computing systems. An appealing and possibly more sustainable alternative is provided by novel neuromorphic paradigms, which directly implement ANNs in hardware. However, little is known about the actual benefits of running ANNs on neuromorphic hardware for use cases in scientific computing. Here, we present a methodology for measuring the energy cost and compute time for inference tasks with ANNs on conventional hardware. In addition, we have designed an architecture for these tasks and estimate the same metrics based on a state-of-the-art analog in-memory computing (AIMC) platform, one of the key paradigms in neuromorphic computing. Both methodologies are compared for a use case in quantum many-body physics in two-dimensional condensed matter systems and for anomaly detection at 40 MHz rates at the Large Hadron Collider in particle physics. We find that AIMC can achieve up to one order of magnitude shorter computation times than conventional hardware at an energy cost that is up to three orders of magnitude smaller. This suggests great potential for faster and more sustainable scientific computing with neuromorphic hardware.
Artificial neural network-based streamline tracing strategy applied to hypersonic waverider design
Authors: Rao Anagha G. , Siddharth Umesh , Rao Srisha M. V.
Published: February 2023

Streamline tracing in hypersonic flows is essential for designing a high-performance waverider and intake. Conventionally, the streamline equations are solved after obtaining the velocity field over a basic flow field from simplified flow differential equations or three-dimensional computational fluid dynamics. The hypersonic waverider shape is generated by repeatedly applying the streamline tracing approach along several planes. This approach is computationally expensive for iterative waverider optimization. We provide a novel strategy where an Artificial Neural Network (ANN) is trained to directly predict the streamlines without solving the differential equations. We consider the standard simple cone-derived waverider using Taylor–Maccoll equations for the conical flow field as a template for the study. First, the streamlines from the shock are solved for a wide range of cone angle and Mach number conditions resulting in an extensive database. The streamlines are parameterized by a third-order polynomial, and an ANN is trained to predict the coefficients of the polynomial for arbitrary inputs of Mach number, cone angle, and streamline originating locations. We apply this strategy to design a cone-derived waverider and compare the geometry obtained with the standard conical waverider design method and the simplified waverider design method. The ANN technique is highly accurate, with a difference of 0.68% from the standard method in the coordinates of the waverider. The performance of the three waveriders is compared using Reynolds averaged Navier–Stokes simulations. The ANN-derived waverider does not indicate severe flow spillage at the leading edge. The new ANN-based approach is 20 times faster than the standard method.
Machine learning assisted interpretation of creep and fatigue life in titanium alloys
Authors: Swetlana Sucheta , Rout Ashish , Singh Abhishek Kumar
Published: February 2023

Making reliable predictions of the mechanical behavior of alloys with a prolonged service life is beneficial for many structural applications. In this work, we propose an interpretable machine learning (ML) approach to predict fatigue life cycles (Nf) and creep rupture life (tr) in titanium-based alloys. Chemical compositions, experimental parameters, and alloy processing conditions are employed as descriptors for the development of gradient boost regression models for log-scaled Nf and tr. The models are trained on an extensive experimental dataset, predicting log-scaled Nf and tr with a very small root mean squared error of 0.17 and 0.15, respectively. An intuitive interpretation of the ML models is carried out via SHapley Additive exPlanations (SHAP) to understand the complex interplay of various features with Nf and tr. The SHAP interpretation of the ML models reveals close agreement with the general creep equation and Wöhler curve of fatigue. The approach proposed in this study can accelerate the design of novel Ti-based alloys with desired properties.
Inducing ferromagnetism and magnetoelectric coupling in the ferroelectric alloy system BiFeO3–PbTiO3 via additives
Authors: Saha Sujoy , Singh Ram Prakash , Rout Ashish , Mishra Aditya , Ali Amanat , Basumatary Himalay , Ranjan Rajeev
Published: February 2023

There is a growing interest in BiFeO3-based alloys because of the possibility it offers for developing high-temperature high-performance piezoelectric materials and for their interesting multiferroic properties. Often such ceramics are synthesized with additives either to reduce/suppress leakage current that the system inherits from the parent compound BiFeO3 or to promote sintering via formation of the liquid phase. We demonstrate here the propensity for stabilizing ferromagnetism in the ferroelectric solid solution BiFeO3–PbTiO3 (BF–PT) when synthesized with additive MnO2. Detailed investigation revealed that the ferromagnetic property of the ceramic is extrinsic and caused by the additive enabled precipitation of trace amount of the ferrimagnetic Pb-hexaferrite phase, not easily detected in conventional x-ray diffraction measurements. We also show that the ferromagnetic property is induced in Co-modified BF–PT. However, in this case, the additive stabilizes the CoFe2O4 spinel ferrite phase. While our findings offer a strategy to develop particulate magnetoelectric multiferroic composites using additive assisted precipitation of the ferrimagnetic phase(s) in BiFeO3-based ferroelectric alloys, it also helps in better understanding of the electromechanical response in BFO-based alloys.
Deep language models for interpretative and predictive materials science
Authors: Hu Yiwen , Buehler Markus J.
Published: February 2023

Machine learning (ML) has emerged as an indispensable methodology to describe, discover, and predict complex physical phenomena that efficiently help us learn underlying functional rules, especially in cases when conventional modeling approaches cannot be applied. While conventional feedforward neural networks are typically limited to performing tasks related to static patterns in data, recursive models can both work iteratively based on a changing input and discover complex dynamical relationships in the data. Deep language models can model flexible modalities of data and are capable of learning rich dynamical behaviors as they operate on discrete or continuous symbols that define the states of a physical system, yielding great potential toward end-to-end predictions. Similar to how words form a sentence, materials can be considered as a self-assembly of physically interacted building blocks, where the emerging functions of materials are analogous to the meaning of sentences. While discovering the fundamental relationships between building blocks and function emergence can be challenging, language models, such as recurrent neural networks and long-short term memory networks, and, in particular, attention models, such as the transformer architecture, can solve many such complex problems. Application areas of such models include protein folding, molecular property prediction, prediction of material failure of complex nonlinear architected materials, and also generative strategies for materials discovery. We outline challenges and opportunities, especially focusing on extending the deep-rooted kinship of humans with symbolism toward generalizable artificial intelligence (AI) systems using neuro-symbolic AI, and outline how tools such as ChatGPT and DALL·E can drive materials discovery.
Polarized emission from hexagonal-silicon–germanium nanowires
Authors: van Tilburg Marvin A. J. , Peeters Wouter H. J. , Vettori Marco , van Lange Victor T. , Bakkers Erik P. A. M. , Haverkort Jos E. M.
Published: February 2023

We present polarized emission from single hexagonal silicon–germanium (hex-SiGe) nanowires. To understand the nature of the band-to-band emission of hex-SiGe, we have performed photoluminescence spectroscopy to investigate the polarization properties of hex-SiGe core–shell nanowires. We observe a degree of polarization of 0.2 to 0.32 perpendicular to the nanowire c-axis. Finite-difference time-domain simulations were performed to investigate the influence of the dielectric contrast of nanowire structures. We find that the dielectric contrast significantly reduces the observable degree of polarization. Taking into account this reduction, the experimental data are in good agreement with polarized dipole emission perpendicular to the c-axis, as expected for the fundamental band-to-band transition, the lowest energy direct band-to-band transition in the hex-SiGe band structure.
In-memory computing with emerging memory devices: Status and outlook
Authors: Mannocci P. , Farronato M. , Lepri N. , Cattaneo L. , Glukhov A. , Sun Z. , Ielmini D.
Published: February 2023

In-memory computing (IMC) has emerged as a new computing paradigm able to alleviate or suppress the memory bottleneck, which is the major concern for energy efficiency and latency in modern digital computing. While the IMC concept is simple and promising, the details of its implementation cover a broad range of problems and solutions, including various memory technologies, circuit topologies, and programming/processing algorithms. This Perspective aims at providing an orientation map across the wide topic of IMC. First, the memory technologies will be presented, including both conventional complementary metal-oxide-semiconductor-based and emerging resistive/memristive devices. Then, circuit architectures will be considered, describing their aim and application. Circuits include both popular crosspoint arrays and other more advanced structures, such as closed-loop memory arrays and ternary content-addressable memory. The same circuit might serve completely different applications, e.g., a crosspoint array can be used for accelerating matrix-vector multiplication for forward propagation in a neural network and outer product for backpropagation training. The different algorithms and memory properties to enable such diversification of circuit functions will be discussed. Finally, the main challenges and opportunities for IMC will be presented.
Flexible metamaterial based microwave absorber with epoxy/graphene nanoplatelets composite as substrate
Authors: Anjali M. , Rengaswamy Kumaran , Ukey Abhishek , Stephen Lincy , Krishnamurthy C. V. , Subramanian V.
Published: February 2023

Customization of substrates for the design of metamaterial absorbers gives the user a wide choice of parameters like flexibility, thickness, dielectric constant, etc. Polymer composites are attractive in this regard as they provide a variety of options to fabricate substrates with desirable properties depending on the matrix and filler materials. In this work, flexible polymer nanocomposites with different weight percentages of graphene nanoplatelets (GnP) in epoxy were fabricated and the dielectric characterization was performed. The presence of GnP increased the real part of the dielectric constant from 2.5 for 0 wt. % to 14.7 for 9 wt. % of the epoxy-GnP composites measured in X-band frequency. The substrate with 5 wt. % of GnP in epoxy having a relative permittivity of 7.3–j0.25 is chosen to design a metamaterial absorber, and the absorption studies are carried out numerically. The proposed absorber having a thickness of λ/22 is shown to have a maximum absorption of 99.8% at the frequency 9.88 GHz. Furthermore, an equivalent circuit model of the absorber is proposed and the analytical values of the circuit elements are determined. The metamaterial prototype is fabricated by coating metallic resonating structures on top of the flexible E-GnP5 substrate of thickness 1.4 mm by thermal evaporation. The performance of the fabricated absorber agrees well with the simulation results. These polymer nanocomposites with good flexibility, thermal stability, and optimum dielectric properties would be the future materials for developing conformal metamaterial absorbers for microwave applications.
Impedance modeling for excluding contact resistance from cross-plane electronic conductivity measurement of anisotropic two-dimensional Ti3C2Tx MXenes
Authors: Makaryan Taron , Okada Yasuaki , Suzuki Keigo
Published: February 2023

We propose impedance spectroscopy modeling as a convenient tool for estimating the cross-plane conductivity of anisotropic two-dimensional materials by excluding contact resistance with the underlying metal electrodes. We showcase this idea on two types of titanium carbide Ti3C2Tx MXenes, wherein Tx represents surface functional termination. These MXenes are synthesized from the same parent MAX phase material (Ti3AlC2) by different synthesis protocols and are studied in their plain as-synthesized states as well as after short annealing. The cross-plane conductivity of MXenes estimated by our approach appears to be up to an order of magnitude higher than is estimated by a conventional one. We validate our impedance modeling approach by comparing the specific contact resistance results derived from it to a direct estimation by transmission line measurement. We also deduce which functional group has a dominant footprint on the conductivity in each studied MXene by performing numerical simulations on cross-plane conductivity as well as on electronic band structures. The novel equivalent circuit developed herein may be extended to other anisotropic thin films to aid their application in various electronic devices.
Effective removal of hexavalent chromium from aqueous system by biochar-supported titanium dioxide (TiO
Authors: Zhu Yuen , Ning Yiru , Li Lingzhi , Chen Zhiying , Li Hua , Zhang Yaxin
Published: February 2023

Environmental context Photocatalytic TiO2 materials are good prospects in water quality treatment due to their stable chemical properties and limited secondary pollution. TiO2 photocatalytic material prepared with biochar as a carrier can greatly improve the photocatalytic efficiency of CrVI, and the removal rate of CrVI can reach 84.4%. This study shows that biochar-supported TiO2 photocatalytic composites are feasible for the green and efficient removal of CrVI from an aqueous phase. Rationale TiO2 has great application prospects in the treatment of chromium-containing wastewater due to its photochemical stability and low toxicity. Loading TiO2 on solid adsorption materials can improve the photocatalytic efficiency and solve the problem of difficult separation and recovery of TiO2. Methodology In this study, biochar-supported TiO2 (BC-TiO2) and acid-washed biochar-supported TiO2 (HBC-TiO2) were prepared by a sol–gel method using biochar (BC) and acid-washed biochar (HBC) as adsorption carriers. The effects of various experimental parameters such as ultraviolet irradiation conditions, catalyst dose and pH on the removal efficiency of CrVI by BC, HBC, BC-TiO2 and HBC-TiO2 were investigated. The structure and morphology of the four materials were characterised. Results The results indicated that under the optimal reaction conditions (pH = 6, dosage of biochar materials/photocatalytic composites = 5 g/6 g), the removal percentage of CrVI changed as BC-TiO2 (Light) (84.43%) > HBC-TiO2 (Light) (80.19%) > BC-TiO2 (Dark) (57.9%) > HBC-TiO2 (Dark) (52.94%) > HBC (30.06%) > BC (14.66%). Loading TiO2 on biochar materials improved the specific surface area and increased the reaction sites when compared with BC and HBC. Discussion This study shows that BC-TiO2 is more suitable to remove CrVI from an aqueous system because of its high removal efficiency. The enrichment of CrVI on the biochars and the close contact between the biochar and TiO2 through the Ti–O–C dense heterojunction promote the interfacial transfer of CrVI, which is the key to the removal of CrVI. This study has great significance for the treatment of chromium-containing wastewater by photocatalytic composites.
Spatially resolved Raman piezospectroscopy for nondestructive evaluation of residual stress in β-Ga2O3 films
Authors: Hara Yasuaki , Zhu Wenliang , Deng Gaofeng , Marin Elia , Guo Qixin , Pezzotti Giuseppe
Published: February 2023

In this paper, the piezospectroscopic effect for β-Ga2O3, i.e. the spectral band shift in response to strain/stress, has been calibrated by the indentation method using spatially resolved Raman spectroscopy for quantitative stress evaluation of Ga2O3 devices, taking advantage of the crack-tip tensile stress field and the spatial probe deconvolution. A series of Vickers indentation prints were introduced on (010) and (

2
ˉ

01

) Ga2O3 single crystals, and the relationships between observed band shifts and residual stresses were clarified to determine the phonon deformation potentials of the Raman bands. Accordingly, a quantitative analysis of the residual stress field in a Ga2O3 thin film grown on (0001) sapphire by plasma-assisted pulsed laser deposition, which revealed the presence of a gradient of incompletely released stress in the depth direction of the film, is shown as an example.
Influence of bovine serum albumin (BSA) on photodynamic properties of meso-tetrakis(sulfonatophenyl) porphyrin (TPPS4) for picosecond pulse trains
Authors: Miao Quan , Sun Erping , Liu Qixin , Song Rengang , Liang Min , Xu Yan
Published: February 2023

Due to the special interest and unique advantage of bovine serum albumin among various proteins, we carried out researches into effects of bovine serum albumin on photophysical characters of meso-tetrakis(sulfonatophenyl) porphyrin. The laser source we chose is picosecond pulse trains containing 20 subpulses of 70 picoseconds width separating by 13 nanoseconds at 532 nanometers. The theoretical analysis was carried out with a generalized five-level model representing the molecular populating structure. The two-dimensional paraxial field combined with the rate equations was solved by Crank-Nicholson numerical method. The nonlinear optical absorption mechanism in porphyrin is mainly two-step two-photon absorption. We found meso-tetrakis(sulfonatophenyl) porphyrin always shows prominent optical limiting effects binding with or without bovine serum albumin. In the presence of bovine serum albumin, the photophysical parameters of porphyrin get certain influence and cause slight weakening of optical limiting for porphyrin.