bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal relaxation of strain and twist in ferroelectric hexagonal boron nitride moiré interfaces
Authors: Hocking Marisa , Henzinger Christina E. , Tran Steven J. , Pendharkar Mihir , Bittner Nathan J. , Watanabe Kenji , Taniguchi Takashi , Goldhaber-Gordon David , Mannix Andrew J.
Published: July 2024

New properties can arise at van der Waals (vdW) interfaces hosting a moiré pattern generated by interlayer twist and strain. However, achieving precise control of interlayer twist/strain remains an ongoing challenge in vdW heterostructure assembly, and even subtle variation in these structural parameters can create significant changes in the moiré period and emergent properties. Characterizing the rate of interlayer twist/strain relaxation during thermal annealing is critical to establish a thermal budget for vdW heterostructure construction and may provide a route to improve the homogeneity of the interface or to control its final state. Here, we characterize the spatial and temporal dependence of interfacial twist and strain relaxation in marginally-twisted hBN/hBN interfaces heated under conditions relevant to vdW heterostructure assembly and typical sample annealing. We find that the ferroelectric hBN/hBN moiré at very small twist angles (θ≤0.1°) relaxes minimally during annealing in air at typical assembly temperatures of 170°C. However, at 400°C, twist angle relaxes significantly, accompanied by a decrease in spatial uniformity. Uniaxial heterostrain initially increases and then decreases over time, becoming increasingly non-uniform in direction. Structural irregularities such as step edges, contamination bubbles, or contact with the underlying substrate result in local inhomogeneity in the rate of relaxation.
Josephson diode effect in a ballistic single-channel nanowire
Authors: Meyer Julia S. , Houzet Manuel
Published: July 2024

When time-reversal and inversion symmetry are broken, superconducting circuits may exhibit a so-called diode effect, where the critical currents for opposite directions of the current flow differ. In recent years, this effect has been observed in a multitude of systems, and the different physical ingredients that may yield such an effect are well understood. On a microscopic level, the interplay between spin–orbit coupling and a Zeeman field may give rise to a diode effect in a single Josephson junction. However, so far, there is no analytical description of the effect within a simple model. Here, we study a single-channel nanowire with Rashba spin–orbit coupling and in the presence of a Zeeman field. We show that the different Fermi velocities and spin projections of the two pseudo-spin bands lead to a diode effect. Simple analytical expressions for the diode efficiency can be obtained in limiting cases.
Reliability of indium-tin-zinc-oxide thin-film transistors under dynamic drain voltage stress
Authors: Zhu Guanming , Chen Zhiying , Zhang Meng , Lu Lei , Deng Sunbin , Wong Man , Kwok Hoi-Sing
Published: July 2024

In this Letter, the reliability of indium-tin-zinc-oxide thin-film transistors (TFTs) under dynamic drain voltage stress is investigated. A degradation phenomenon, associated with both pulse rising time (tr) and falling time, is observed. Through the technology computer-aided design simulation and recovery experiment, it is discovered that the tr-dependent dynamic hot carrier effect and integral voltage-dependent electron detrapping jointly affect the device's reliability. Finally, an AC degradation model in indium-tin-zinc oxide TFTs, considering the non-equilibrium junction, hot carrier injection, and recovery, was proposed.
Strong stretching theory of polydisperse curved polymer brushes
Authors: Giannakou Marios , Borisov Oleg V. , Schmid Friederike
Published: July 2024

We investigate the effect of polydispersity on the properties of curved linear brushes in good solvent and for molten brushes. To this end, we extend the strong stretching theory for polydisperse brushes to curved geometries and investigate the polymer chain end profiles, bending moduli and other properties for experimentally relevant polymer chain length distributions of the Schulz–Zimm type. We also investigate the properties of end exclusion zones that may appear in convex geometries under certain conditions and show that their position in the brush can be engineered by careful selection of the polymer length distribution. Finally, we propose a method to engineer chain end profiles by engineering the polymer length distribution.
Polarization control of attosecond pulses from laser-nanofoil interactions using an external magnetic field
Authors: Zagidullin R. , Zorina V. , Wang J. W. , Rykovanov S. G.
Published: July 2024

In this paper, we analyze the extended model of the dynamics of a thin plasma layer under the influence of a short laser pulse with a constant magnetic field. The model predictions show good correspondence to the single and multi-particle particle-in-cell simulations. It is also demonstrated that polarization of the attosecond extreme ultraviolet radiation generated by a short intense laser pulse interacting with a thin foil could be tuned using an external magnetic field via the Faraday effect.
The effect of polyvinylpyrrolidone modified nano-polymers on rheological properties of silicon-based shear thickening fluid
Authors: Wang Geng , Sun Li , Zhang Chunwei
Published: July 2024

Graphene oxide and carbon nanotubes have wide application prospects in many fields due to their unique micro-morphology. In this work, the surface of graphene oxide and carbon nanotubes was simply modified by polyvinylpyrrolidone to graft them together to form a composite cluster which was called GCP. A new shear thickening fluid (GCP/SiO2-STF) was developed by dispersing GCP-composite clusters and nano-silica particles into polyethylene glycol (PEG200). It is found that compared with SiO2-STF, GCP/SiO2-STF can exhibit better shear thickening behavior due to the complex spatial structure and viscous surface of GCP-composite cluster. The relationship between graphene oxide, carbon nanotubes, polyethylpyrroxanone, and nano-silica was analyzed by scanning electron microscopy, and the thickening behavior of GCP/SiO2-STF was explained. The influence of the mass ratio of graphene oxide to carbon nanotubes on the rheological properties of GCP/SiO2-STF was studied by steady-state rheological tests. When the mass ratio of graphene oxide to carbon nanotubes was 0.3, the peak viscosity of GCP/SiO2-STF3 was 468.55 Pa⋅s, which was 116.51% higher than that of SiO2-STF. Second, temperature and plate spacing can significantly change the rheological parameters of GCP/SiO2-STF3. The test results are of great significance for controlling the thickening behavior of STF in order to adapt to complex conditions. In addition, the oscillatory shear test results show that GCP/SiO2-STF3 has excellent energy dissipation performance in different stages. More importantly, this work could find its use for GCP/SiO2-STF in a variety of engineering applications, such as body armor, shock absorption devices, and sports equipment.
A compositional numerical study of vapor–liquid-adsorbed three-phase equilibrium calculation in a hydraulically fractured shale oil reservoir
Authors: Wang Yuhan , Lei Zhengdong , Xu Zhenhua , Liu Yishan , Pan Xiuxiu , Wang Yanwei , Liu Pengcheng
Published: July 2024

The development of carbon capture, utilization, and storage technologies has notably advanced CO2-enhanced oil recovery (EOR) in shale oil reservoirs, which are characterized by abundant nanopores. These nanopores induce unique phase behaviors in hydrocarbons, challenging traditional phase equilibrium calculation methods. This paper presents a novel three-phase thermodynamic model (vapor–liquid-adsorbed three-phase equilibrium calculation) that addresses these challenges by considering the nanopore capillary pressure, critical parameter transitions, and material exchange between the adsorbed and bulk phases. Grounded in the multicomponent Langmuir–Freundlich adsorption equation and the Peng Robinson equation of state, this model is integrated into the MATLAB Reservoir Simulation Toolbox using an embedded discrete fracture model framework, enabling detailed study of CO2 and hydrocarbon phase behaviors within shale oil nanopores. The results reveal that there are significant nano-constrained effects on multicomponent fluid phase behavior, particularly in pores smaller than 20 nm, leading to notable changes in bubble and dew point pressures, as well as critical condensation pressures and temperatures. CO2 injection further complicates the system, enhancing interactions and expanding the coexistence region of the liquid and gas phases on the pressure–temperature diagram, especially across varying pore sizes. Optimization research on CO2 huff and puff technical parameters for shale oil reservoirs suggests the following optimal settings: a CO2 injection rate of 100 t/day, a shut-in time of 30 days, and six huff and puff cycles. The results of this study offer critical insights into CO2-EOR mechanisms in shale oil reservoirs and emphasize the importance of nanopore properties in EOR.
Effect of pressure, nitrogen-doping, and lanthanide elements substitution on the superconductivity of rocksalt-type LuH
Authors: Jiang Kai-Yue , Chen Ying-Jie , Lu Hong-Yan
Published: July 2024

The report on near-ambient superconductivity in nitrogen-doped lutetium hydride is still under controversy. Here, guided by x-ray diffraction data of nitrogen-doped lutetium hydride, we choose a possible cubic superconducting phase named rocksalt-type LuH (RS-LuH) and study the superconductivity of pristine RS-LuH, nitrogen-doped RS-LuH named Lu4NH3, and lanthanide elements substitution of RS-LuH at pressures 0, 1, and 10 GPa by performing density functional theory and isotropic Eliashberg equation. As pressure increases from 0 to 10 GPa, all phonon spectra notably harden, resulting in the suppression of electron–phonon coupling. Moreover, the decrease in superconducting critical temperature (Tc) of Lu4NH3 is due to the reduction of electron–phonon coupling and the density of states at the Fermi level compared with pristine RS-LuH. Finally, our investigation reveals a monotonic increase in Tc with ascending atomic numbers via lanthanide element substitution. Notably, RS-LuH exhibits the highest Tc (Tc=19.7 K) among all compounds we studied. Therefore, our theoretical exploration enriches the understanding of the superconductivity in nitrogen-doped lutetium hydride under varying pressures.
Two-dimensional vector field topology and scalar fields in viscous flows: Reconstruction methods
Authors: Liu Tianshu , Salazar David M.
Published: July 2024

This paper discusses the reconstruction of the two-dimensional (2D) vector field topology (VFT) from a 2D scalar potential field and vice versa. The physical foundation of the proposed reconstruction method is the convection-type equation coupling a 2D vector field (e.g., skin friction) with a 2D potential field (e.g., surface pressure, temperature, or scalar concentration) in viscous flows. To reconstruct the VFT, a variational method is applied to this inverse problem, and then, an approximate method is proposed based on the linear superposition of some elemental potential field structures with simple analytical forms (source, vortex, saddle, etc.). As examples, the proposed method is applied to swept shock-wave/boundary-layer interaction and near-wall turbulence. Furthermore, in a reversed process to reconstruct a 2D potential field from a 2D vector field, a similar variational method is applied, and an approximate method with a constant source term in the convection-type relation is proposed, which is particularly applicable to reconstruction of a surface pressure field from global skin friction measurements in aerodynamics experiments. The significance of this work is that the complex VFT can be reconstructed based on a scalar potential field by using a semi-analytical approach. The proposed method can be used in fluid mechanics and other disciplines such as computer graphics and data visualization.
Manganese–rhodium nanoparticles: Adsorption on titanium oxide surfaces and catalyst for syngas reactions
Authors: Marcos P. A. , Aguilar N. , Rozas S. , Martel S. , Bol A. , Aparicio S.
Published: July 2024

Manganese–rhodium (Mn–Rh) nanoparticles have emerged as a promising candidate for catalytic applications in the production of syngas, a critical precursor for a wide range of industrial processes. This study employs a comprehensive, theoretical, and computational approach to investigate the structural and electronic properties of Mn–Rh nanoparticles, with a specific focus on their interaction with titanium oxide (TiO2) surfaces and their potential as catalysts for syngas reactions. The density functional theory calculations are employed to explore the adsorption behavior of Mn–Rh nanoparticles on TiO2 surfaces. By analyzing the adsorption energies, geometries, and electronic structure at the nanoscale interface, we provide valuable insights into the stability and reactivity of Mn–Rh nanoparticles when immobilized on TiO2 supports. Furthermore, the catalytic performance of Mn–Rh nanoparticles in syngas production is thoroughly examined. Through detailed reaction mechanism studies and kinetic analysis, we elucidate the role of Mn and Rh in promoting syngas generation via carbon dioxide reforming and partial oxidation reactions. The findings demonstrate the potential of Mn–Rh nanoparticles as efficient catalysts for these crucial syngas reactions. This research work not only enhances our understanding of the fundamental properties of Mn–Rh nanoparticles but also highlights their application as catalysts for sustainable and industrially significant syngas production.
Magnonics: Materials, physics, and devices
Authors: Han Xiufeng , Wu Hao , Zhang Tianyi
Published: July 2024

Magnon, the quanta of spin waves, can serve as an efficient spin information carrier for memory and logic applications, with the advantages of the Joule-heating free induced low power-dissipation property and the phase-coherent induced quantum phenomena. In analogy to spintronics, magnonics focuses on the excitation, detection, and manipulation of magnons (spin waves). In recent years, with the development of nanotechnology, abundant magnonic phenomena emerge in the nanoscale, such as the spin Seebeck effect, magnon-mediated electric current drag effect, magnon valve effect, magnon junction effect, magnon resonant transimission, magnon transfer torque, spin wave propagation, subterahertz spin wave excitation, magnon Bose–Einstein condensation, and so on. Here, we review the recent progresses in magnonics from physics, materials to devices, shedding light on the future directions for magnonics.
Rational localized wave patterns in the form of Schur polynomials for the (2 + 1)-dimensional Bogoyavlenskii–Kadomtsev–Petviashvili-I equation in fluid dynamics
Authors: Liu Qingxing , Wang Chuanjian , Tang Yuan , Li Changzhao
Published: July 2024

In this paper, we derive a family of rational localized wave solutions with any order in the Bogoyavlenskii–Kadomtsev–Petviashvili-I equation in terms of the Kadomtsev–Petviashvili reduction method. These rational localized waves are expressed by the Grammian determinants, and the entries of the determinant are presented by means of the Schur polynomials, which provide convenience in discussing the dynamics of localized wave solutions. According to the parity of the element indexes in the higher-order determinants, we mainly discuss two different types of higher-order rational localized wave solutions. Tuning the free parameters of the higher-order rational localized waves, lump-type localized waves of various polygon patterns, such as triangle, quadrangle, and pentagon, are obtained. It is shown that when one of these free parameters in the higher-order rational localized waves becomes sufficiently large, the localized wave solutions given by the odd indexes element are made up of the first-order fundamental rational localized wave. However, the higher-order rational localized wave solutions given by the even indexes element can exhibit not only the polygon wave patterns given by the first-order fundamental rational localized wave but also other novel hybrid wave patterns. These hybrid wave patterns consist of the first-order fundamental rational localized wave and other higher-order fundamental rational localized wave. These results will help us to better understand the wave patterns and control of nonlinear localized waves in fluid dynamics.
An improved physical information network for forecasting the motion response of ice floes under waves
Authors: Peng Xiao , Wang Chunhui , Xia Guihua , Han Fenglei , Liu Zhuoyan , Zhao Wangyuan , Yang Jianfeng , Lin Qi
Published: July 2024

Physics-informed neural networks (PINNs) have increasingly become a key intelligent technology for solving partial differential equations. Nevertheless, for simulating the dynamic response of ice floes to waves, researchers often still resort to traditional numerical methods and empirical formulas. The limitations of these methods include extended computational durations and challenges in precisely conforming to physical principles. To effectively overcome these challenges and achieve efficient and accurate prediction of sea ice motion response, this study proposes an improved PINN method for the longitudinal motion response of sea ice under regular wave action. The approach features two principal innovations: first, a neural network loss function module tailored to the ice motion response equations, and second, an attention mechanism focused on temporal sequences and wave data. Through case studies of sea ice motion under three different wave conditions, this research validates the effectiveness of the improved PINN method. A comparison between the network's training and testing outcomes with experimental figures reveals significant consistency, affirming the method's robustness and accuracy. The application of this study demonstrates the potential for accurately predicting the dynamic response of sea ice in complex sea conditions, providing significant technical support and new research directions for future studies.
Charge pumping in h-BN-encapsulated graphene driven by surface acoustic waves
Authors: Nichols Dublin M. , Berg Jameson G. , Taniguchi Takashi , Watanabe Kenji , Dhagat Pallavi , Deshpande Vikram V. , Jander Albrecht , Minot Ethan D.
Published: July 2024

Surface acoustic waves (SAWs) on piezoelectric insulators can generate dynamic periodic potentials inside one-dimensional and two-dimensional materials. These periodic potentials have been utilized or proposed for various applications, including acoustoelectric charge pumping. In this study, we investigate acoustoelectric charge pumping in graphene with very low electrostatic disorder. By employing a graphite top gate on boron-nitride-encapsulated graphene, we adjust the graphene carrier concentration over a broad range, enabling us to examine the acoustoelectric signal in both mixed-carrier and single-carrier regimes. We discuss the benefits of h-BN-encapsulated graphene for charge pumping applications and introduce a model that describes the acoustoelectric signal across all carrier concentrations, including at the charge neutrality point. This quantitative model will support future SAW-enabled explorations of phenomena in low-dimensional materials and guide the design of novel SAW sensors.
Structural color in the bacterial domain: The ecogenomics of a 2-dimensional optical phenotype
Authors: Zomer Aldert , Ingham Colin J. , von Meijenfeldt F. A. Bastiaan , Escobar Doncel Álvaro , van de Kerkhof Gea T. , Hamidjaja Raditijo , Schouten Sanne , Schertel Lukas , Müller Karin H. , Catón Laura , Hahnke Richard L. , Bolhuis Henk , Vignolini Silvia , Dutilh Bas E.
Published: July 2024

Structural color is an optical phenomenon resulting from light interacting with nanostructured materials. Although structural color (SC) is widespread in the tree of life, the underlying genetics and genomics are not well understood. Here, we collected and sequenced a set of 87 structurally colored bacterial isolates and 30 related strains lacking SC. Optical analysis of colonies indicated that diverse bacteria from at least two different phyla (
Bacteroidetes
and
Proteobacteria
) can create two-dimensional packing of cells capable of producing SC. A pan-genome-wide association approach was used to identify genes associated with SC. The biosynthesis of uroporphyrin and pterins, as well as carbohydrate utilization and metabolism, was found to be involved. Using this information, we constructed a classifier to predict SC directly from bacterial genome sequences and validated it by cultivating and scoring 100 strains that were not part of the training set. We predicted that SCr is widely distributed within gram-negative bacteria. Analysis of over 13,000 assembled metagenomes suggested that SC is nearly absent from most habitats associated with multicellular organisms except macroalgae and is abundant in marine waters and surface/air interfaces. This work provides a large-scale ecogenomics view of SC in bacteria and identifies microbial pathways and evolutionary relationships that underlie this optical phenomenon.
Orthogonality of sensory and contextual categorical dynamics embedded in a continuum of responses from the second somatosensory cortex
Authors: Bayones Lucas , Zainos Antonio , Alvarez Manuel , Romo Ranulfo , Franci Alessio , Rossi-Pool Román
Published: July 2024

How does the brain simultaneously process signals that bring complementary information, like raw sensory signals and their transformed counterparts, without any disruptive interference? Contemporary research underscores the brain’s adeptness in using decorrelated responses to reduce such interference. Both neurophysiological findings and artificial neural networks support the notion of orthogonal representation for signal differentiation and parallel processing. Yet, where, and how raw sensory signals are transformed into more abstract representations remains unclear. Using a temporal pattern discrimination task in trained monkeys, we revealed that the second somatosensory cortex (S2) efficiently segregates faithful and transformed neural responses into orthogonal subspaces. Importantly, S2 population encoding for transformed signals, but not for faithful ones, disappeared during a nondemanding version of this task, which suggests that signal transformation and their decoding from downstream areas are only active on-demand. A mechanistic computation model points to gain modulation as a possible biological mechanism for the observed context-dependent computation. Furthermore, individual neural activities that underlie the orthogonal population representations exhibited a continuum of responses, with no well-determined clusters. These findings advocate that the brain, while employing a continuum of heterogeneous neural responses, splits population signals into orthogonal subspaces in a context-dependent fashion to enhance robustness, performance, and improve coding efficiency.
Levels of metaphor in gesture
Authors: Dyrmo Tomasz
Published: July 2024

The present contribution integrates a recent, multilevel approach to metaphor advanced by Kövecses (2017 and later publications), with gestures as a mode of metaphorical expression. In
doing so, the paper shows how different elements of conceptual structure, varying from the abstract, recurring image schema,
through more complex conceptual domains and frames, to contextually embedded and variable metaphorical scenarios, participate in
the metaphoricity of gestures. This application of gestures to the multilevel approach lends direct support to the idea that human
conceptual system recruits various semiotic modes – not limited to language – for expressing its content. Image schemas of
object and source-path-goal have been shown to participate directly in the domain of transfer,
which, when embedded in context of a given communicative situation, has become the conceptual frame of coming out. The frame, when
realised via different gestural forms in a shared context across many speakers, turns into a highly context-sensitive, variable,
and speech co-expressive gestural metaphorical scenario of coming out is showing an object.
The visibility of speech
Authors: Garello Stefana
Published: July 2024

The aim of this paper is to explore the relationship between visual imagery and metaphor, highlighting the
historical neglect of this relationship in philosophy and cognitive science and exploring the reasons behind this neglect in
theoretical and empirical studies. After outlining influential philosophical theories on the relationship between metaphor and
visual imagery, I provide a critical overview of empirical findings on this. Thus, I argue that experimental studies lack
sufficient empirical evidence to make meaningful generalizations and fail to determine the true role of visual imagery in metaphor
comprehension. Nevertheless, they do not allow us to rule out the involvement of imagery in the comprehension of at least certain
metaphors. The present paper proposes that visual imagery might play different roles depending on the semantic features of the
vehicle and the kind of meaning conveyed by different types of metaphors. I conclude this discussion by sketching a roadmap for
further exploration of this fascinating and challenging relationship.
On comprehending adjectival antonyms and negation
Authors: Golshaie Ramin , Incera Sara , Ghaffarzadeh Samira
Published: July 2024

This study explores the extent to which comprehending negated antonyms in Persian involves the mitigation effect,
whereby a negated word means less than its antonym. In two mouse-tracking experiments, participants rated sentences containing
negated/non-negated scalar (e.g., tall-short) and complementary (e.g., dead-alive) antonymous
adjectives on a continuous scale. Their reaction times and mouse movements were recorded by MouseTracker. The analysis of reaction
times shows that negated adjectives are processed slower than their affirmative counterparts. Moreover, the analysis of mouse
trajectories shows that complementary adjectives are rated further apart, closer to the endpoints of the scale than scalar
adjectives. We also found that both complementary and scalar adjectives are mitigated under negation, but the mitigation effect is
greater in scalar, rather than complementary, adjectives. The results speak in favor of a particular kind of mitigation effect,
so-called negative strengthening, which causes negated antonyms to receive a strong pragmatic interpretation towards the opposite
member of the pair.
Promoting Ethnoveterinary Medicine for Sustainable Animal Husbandry Practices in Northern Ghana
Authors: Crump Lisa , Awuni Foster , Avornyo Franklin
Published: July 2024

This case profiles the project ‘Promoting Ethnoveterinary Medicine for Sustainable Animal Husbandry Practices in Northern Ghana’, which brought together stakeholders from the animal and plant health/agriculture sectors to collaborate with farmers, educators, and community and government/ministry decision makers. The 3-year pilot worked to improve animal health and productivity for rural farmers through increased recognition and use of ethnoveterinary medicine (EVM) as a complement to conventional veterinary services. Project activities documented herbal treatments commonly used for poultry and livestock by smallholder farmers, improved preparation, packaging and use of the prioritized treatments, and established a strong network of EVM practitioners in Northern Ghana. Using a participatory integrated approach enabled tangible results, which directly benefited farmers, EVM innovators and the veterinary sector through this small-scale pilot study. Participatory transdisciplinary approaches take time and trust to come to fruition. A follow-on project was collaboratively developed, funded and launched in June 2023 with the intention to continue the successful work.

Information

© The Authors 2024
Stabilization of Sn2+ in FA0.75MA0.25SnI3 perovskite thin films using an electron donor polymer, PCDTBT, and an improvement in the charge transport properties of perovskite solar cells
Authors: Vishwakarma Ashok , Kumar Pankaj , Pandey Anand , Kumar Lokendra
Published: July 2024

Lead-free tin halide perovskites for the fabrication of perovskite solar cells have attracted considerable attention due to their outstanding optoelectronic and ecofriendly properties. These materials face severe issues, such as poor environmental stability, low formation energy and faster oxidation of tin from the Sn2+ to Sn4+ state, leading to poor film quality and self-doping. In this work, we have fabricated FA0.75MA0.25SnI3 perovskite thin films via a solution processing method and studied the conjugated polymer poly [N-9′-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadia-zole)] (PCDTBT)-induced effects in perovskite thin films. The micro-strain of PCDTBT-doped FA0.75MA0.25SnI3 perovskite reduced without any change in the crystal structure. Reductions in electron trap density have been observed due to improved film quality and enlarged perovskite grains. We have observed that the Sn4+ content in 0.050 wt% PCDTBT-doped FA0.75MA0.25SnI3 perovskite film gets reduced, as shown in the x-ray photoelectron spectroscopy (XPS) results. The reduction in Sn4+ (cause of self-doping) content shows that PCDTBT doping maintains the stability of Sn2+ in FA0.75MA0.25SnI3 perovskite thin film. A decrement in hole density from 3.2 × 1018 cm−3 for pristine films to 1.3 × 1017cm−3 for 0.050 wt% PCDTBT-doped FA0.75MA0.25SnI3 perovskite has been observed from C–V measurement, which is consistent with the XPS results. Thus, PCDTBT doping in perovskite films can effectively tackle the severe issues of tin oxidation and defects in the lead-free tin halide perovskite photoactive layer for solar cell application.
Breakdown voltage enhancement and specific on-resistance reduction in depletion-mode GaN HEMTs by co-modulating electric field
Authors: Luo Ling , Wu Nengtao , Xing Zhiheng , Li Shanjie , Zeng Fanyi , Cao Ben , Wu Changtong , Li Guoqiang
Published: July 2024

In this letter, a depletion-mode GaN high electron mobility transistors (GaN HEMTs) with high breakdown voltage and low on-resistance are designed and experimentally demonstrated. It combines the gate field plate and partial unintentionally doped GaN (u-GaN) cap layer (gate field plate and partial u-GaN cap HEMTs: GPU-HEMTs) to co-modulate the surface electric field distribution, which results in the electric field peak being far away from the gate edge, thus improving the breakdown voltage and decreasing the on-resistance. The optimized GPU-HEMTs exhibit a larger output current (I
DS) of 495 mA mm−1 and a correspondingly smaller specific on-resistance of 4.26 mΩ·cm2. Meanwhile, a high breakdown voltage of 1044 V at I
DS = 1 mA mm−1 compared to the conventional GaN HEMTs of 633 V was obtained. This approach is highly effective in simultaneously optimizing the breakdown voltage and the specific on-resistance of GaN HEMTs, while maintaining a large output current.
First-principles study on the electronic structure and photocatalytic properties of novel two-dimensional Janus CrXCN4 (X = Si, Ge)
Authors: Huang Mengya , Lang Qizhi , Wang Yi , Guo Xiang , Ding Zhao , Yan Jiang , Liu Xuefei
Published: July 2024

Abundant studies demonstrate the significant role of Janus-structured two dimensional semiconductors as photocatalytic materials, highlighting their substantial advantages and importance in photocatalysis. In this work, CrXCN4 (X = Si, Ge) Janus monolayers were constructed based on CrC2N4, and the thermal stability, thermodynamic stability, mechanical stability, electronic properties, and optical properties of the monolayers were systematically investigated. Furthermore, an investigation was conducted to examine the impact of biaxial strain on their electronic and light absorption properties. The findings reveal that both monolayers exhibit direct band gap characteristics, with high absorption coefficients for visible light owing to their appropriate band gaps (1.44 eV for CrSiCN4 and 1.15 eV for CrGeCN4, respectively). At compressive strains exceeding 3%, the CrSiCN4 monolayer demonstrates an optimal band edge position, suggesting its potential as a photocatalyst for overall water splitting. Furthermore, as the compressive strain increases, the absorption spectra have blue-shifted and the absorption coefficient becomes higher, exceeding 2

×

105 cm−1 under a −3% compressive strain. Our study highlights the potential applications of CrXCN4 monolayers in the field of optoelectronic device, particularly emphasizing the promising candidacy of CrSiCN4 as an efficient photocatalyst.
Integration of two different road network models for emergency rescue pathfinding in indoor and outdoor environments
Authors: Zhu Zhengliang , Hu Cong , Chen Weiwang , Wang Xinzhi
Published: July 2024

The environment of buildings and outdoor transportation in urban areas is becoming increasingly complex. This poses a challenge for rescue pathfinding once an emergency occurs, which relies on the generation of road network models. To better balance efficiency and accuracy in pathfinding, a three-dimensional integrated road network model (3D-IRNM) derived from grid and topological road network models was developed in this study. Firstly, a cross-platform data loading method from building information model to geographic information systems (GIS) is proposed, to serve as a data source for road network model generation, visual enhancement, and breaking the barriers between different spatial data format models. Then, the topological and grid road network models are generated in indoor spaces of different functions, with IRNM obtained by the integration strategy. The 3D-IRNM can be formed by extracting indoor vertical paths from the stairs and connecting them with the IRNM of each floor. To further combine the 3D-IRNM with outdoor environments, a CrossNode model is then proposed. Besides, an adaptive pathfinding algorithm is also proposed. Finally, the construction of an emergency pathfinding system based on GIS technology is achieved. The pathfinding algorithm and the structure of 3D-IRNM help the pathfinding both efficiency and accuracy. The practicability of the designed 3D-IRNM together with its pathfinding algorithm is well verified.
Nanomaterials for diabetes: diagnosis, detection and delivery
Authors: Verma Jaya , Dahiya Shakti
Published: July 2024

537 million people worldwide suffer from diabetes mellitus, a problem of glucose management that is related to a number of major health risks, including cardiovascular diseases. There is a need for new, efficient formulations of diabetic medications to address this condition and its related consequences because existing treatments have a number of drawbacks and limits. This encouraged the development of treatment plans to get around some of these restrictions, like low therapeutic drug bioavailability or patients’ disobedience to existing therapies. Approaches based on nanotechnology have a lot of promise to enhance the treatment of diabetic patients. In order to manage blood glucose, this review article highlights recent developments and explores the potential applications of different materials (polymeric, ceramic, dendrimers, etc.) as nanocarriers for the delivery of insulin and other antidiabetic medications. Using an injectable and acid-degradable polymeric network produced by the electrostatic interaction of oppositely charged dextran nanoparticles loaded with insulin and glucose-specific enzymes, we reviewed a glucose-mediated release approach for the self-regulated delivery of insulin, in which, after a degradable nano-network was subcutaneously injected into type 1 diabetic mice, in vivo experiments confirmed that these formulations improved glucose management. In addition, a discussion of silica-based nanocarriers, their potential for treating diabetes and controlling blood glucose levels, and an explanation of the role of dendrimers in diabetes treatment have been covered. This is done by utilizing the properties of silica nanoparticles, such as their tuneable particle and pore size, surface chemistry, and biocompatibility. The article summarized the significance of nanomaterials and their uses in the diagnosis and treatment of diabetes overall, illuminating the field’s potential and outlining its prospects for the future.
Antimony-assisted controlled growth of PtSe2 ribbon arrays for enhanced hydrogen evolution reaction
Authors: Li Tian , Yang Liusi , Zhang Guangjie , Zhang Jiaying , Feng Jingqi , Peng Xinying , Xu Peng , He Shuli , Ma Donglin
Published: July 2024

In this study, we report the successful synthesis of few-layer parallel PtSe2 ribbons on an Au foil employing a surface melting strategy via the chemical vapor deposition growth method at 650 °C. The controlled formation of parallel ribbons was directed by the Au steps generated through antimony treatment. These ribbons exhibit an average length of exceeding 100 μm and a width of approximately 100 nm across a substantial area. Electrocatalysis measurements showcase the catalytic performance of PtSe2 ribbons grown on Au foil, which can be further augmented through subsequent oxidation treatment. This investigation introduces an effective growth method for few-layer ribbons at low temperatures and broadens the scope of employing the substrate-guided strategies for the synthesis of one-dimensional materials. Additionally, it underscores the potential of PtSe2 ribbons as an electrocatalyst for hydrogen evolution.
Quench protection for high-temperature superconductor cables using active control of current distribution
Authors: Marchevsky M , Prestemon S
Published: July 2024

Superconducting magnets of future fusion reactors are expected to rely on composite high-temperature superconductor (HTS) cable conductors. In presently used HTS cables, current sharing between components is limited due to poorly defined contact resistances between superconducting tapes or by design. The interplay between contact and termination resistances is the defining factor for power dissipation in these cables and ultimately defines their safe operational margins. However, the current distribution between components along the composite conductor and inside its terminations is a priori unknown, and presently, no means are available to actively tune current flow distribution in real-time to improve margins of quench protection. Also, the lack of ability to electrically probe individual components makes it impossible to identify conductor damage locations within the cable. In this work, we address both problems by introducing active current control of current distribution between components using cryogenically operated metal-oxide-semiconductor-field-effect transistors (MOSFETs). We demonstrate through simulation and experiments how real-time current controls can help to drastically reduce heat dissipation in a developing hot spot in a two-conductor model system and help identify critical current degradation of individual cable components. Prospects of other potential uses of MOSFET devices for improved voltage detection, AC loss-driven active quench protection, and remnant magnetization reduction in HTS magnets are also discussed.
Equation of spin motion for a particle with electric and magnetic charges and dipole moments
Authors: Silenko Alexander J
Published: July 2024

The general classical equation of spin motion is rigorously derived for a particle with electric and magnetic charges and electric and magnetic dipole moments in electromagnetic fields. The equation describing the spin motion relative to the momentum direction in storage rings is also obtained. The importance of the derivation follows from the potential presence of magnetic charges and EDMs due to the pseudoscalar CP-violating electromagnetic interaction caused by dark matter axions.
Quantum simulation of entanglement dynamics in a quantum processor
Authors: Saavedra-Pino Sebastián , Inzulza Cristian , Román Pablo , Albarrán-Arriagada Francisco , Retamal Juan Carlos
Published: July 2024

We implement a five-qubit protocol in IBM quantum processors to study entanglement dynamics in a two qubit system in the presence of a simulated environment. Specifically, two qubits represent the main system, while another two qubits serve as the environment. Additionally, we employ an auxiliary qubit to estimate the quantum entanglement. Specifically, we observe the sudden death and sudden birth of entanglement for different inital conditions that were simultaneously implemented on the IBM 127-qubit quantum processor ibm _brisbane. We obtain the quantum entanglement evolution of the main system qubits and the environment qubits averaging over N = 10 independent experiments in the same quantum device. Our experimental data shows the entanglement and disentanglement signatures in system and enviroment qubits, where the noisy nature of current quantum processors produce a shift on times signaling sudden death or sudden birth of entanglement. This work takes relevance showing the usefulness of current noisy quantum devices to test fundamental concepts in quantum information.
Investigating improvement in the performance of WS2 absorber layer based thin film solar cell with a hole transport layer of Indium Telluride
Authors: Pandey Bhasker , Mishra Rajan , Chauhan R K , Patel Alok Kumar
Published: July 2024

In this work, Tungsten Disulfide (WS2) is used as absorber layer with Indium Telluride (In2Te3) as hole transport layer and a comparison is made between the devices without and with hole transport layer. Analysis is carried out by varying thickness of WS2, Acceptor concentration of WS2, Interface defects, Temperature, Surface recombination velocities, Series and Shunt Resistances. It is observed that by introducing hole transport layer of Indium Telluride, carrier recombination losses can be restricted and the power conversion efficiency of proposed solar cell can be raised significantly. The efficiency of Tungsten Disulfide absorber layer based solar cell is 23.13% when hole transport layer is not inserted, whereas by incorporating a hole transport layer of Indium Telluride, it is increased to 25.37%. SCAPS-1D is used for simulation of the model.
Astrometry as a Tool for Discovering and Weighing Faint Companions to Nearby Stars
Authors: Brandt Timothy D.
Published: July 2024

This tutorial covers the use of absolute astrometry, in particular from the combination of the Hipparcos and Gaia missions, to identify faint companions to nearby stars and to measure the masses and orbits of those companions. Absolute astrometry has been used with increasing success to discover new planets and brown dwarfs and to measure masses and orbits for systems with periods as long as centuries. This tutorial summarizes the nature of the underlying astrometric data, the approach typically used to fit orbits, and the assumptions about that data implicit throughout the process. It attempts to provide intuition for the sensitivity of astrometry as a function of stellar and companion properties and how the available constraints depend on the character and quantity of data available. This tutorial is written for someone with some background in astronomy but with no more than a minimal acquaintance with astrometry or orbit fitting.
The Astrometric Performance of the China Space Station Telescope (CSST) Sky Survey in Extending the Gaia Celestial Reference Frame
Authors: Yao Jun , Liu Jia-Cheng , Liu Niu , Zhu Zi , Wang Zhen-Wei
Published: July 2024

The multi-color imaging sky survey conducted by the China Space Station Telescope (CSST) holds significant promise for advancing the development of the celestial reference frame. In this study, we focus on assessing the astrometric performance of the CSST celestial reference frame (CSST-CRF) in extending the Gaia Celestial Reference Frame 3 (Gaia-CRF3). First, the orientation precision of the CSST reference frame is evaluated using a simulated set of extragalactic sources with CSST g magnitudes ranging from 18 to 25 mag. The estimated orientation uncertainty caused by random error insignificantly affects the alignment between Gaia-CRF3 and the CSST-CRF. Then, the systematic effect of incomplete CSST sky coverage on the alignment between CSST-CRF and Gaia-CRF3 is discussed by analyzing the differences between the subset of Gaia-CRF3 in the CSST observation region (Gaia-CRF3′) and Gaia-CRF3 as a whole. Using the third International Celestial Reference Frame (ICRF3) S/X band as an intermediate reference frame, the orientation offset between Gaia-CRF3′ and Gaia-CRF3 is estimated to be 20 μas. This offset is marginally larger than the orientation offset between Gaia-CRF3 and the ICRF3, approximately 15 μas. The residual spin and glide rate of Gaia-CRF3′ are derived from the proper motions, consistent with that of Gaia-CRF3 within the formal error. Finally, we explore the role of CSST in establishing a multi-band celestial reference frame by comparing its limiting magnitude and observation accuracy with existing catalogs in the infrared and ultraviolet bands. Thanks to its broad wavelength coverage and high-precision measurements, CSST is well-positioned to make significant contributions to the development of a multi-band celestial reference frame.
Drought and energy stock markets in the United States
Authors: Kim Seongeun , Jeon Jooyoung , Kim Hyungjun
Published: July 2024

Amid increasing concerns about the impact of climate change on financial asset pricing, this paper investigates how drought risk affects stock returns in the U.S. energy sector over a thirty-year period (1990–2019). To this end, we ranked energy companies based on the long-term trend of the Palmer drought severity index (PDSI) to compare stock performance between groups experiencing the most significant increases and decreases in drought risk. Our analysis indicates that firms located in drought-prone regions have lower stock returns than those in regions with decreasing drought risk, particularly since 2010. This finding is noteworthy, as the average PDSI trend gap between regions at high risk of drought and those at low risk has widened during this period. We further divide our sample of energy companies into two subsectors-fuel production and electric utility-and find that the stock prices of both subsectors have been negatively affected by drought risk since 2010. The study underscores the energy sector’s dependency on water availability, suggesting novel implications for policymakers and investors in assessing the financial impacts of drought risks in their climate-related decision-making.
State space reconstruction of Markov chains via autocorrelation structure
Authors: Jakovác Antal , Kurbucz Marcell T , Telcs András
Published: July 2024

Understanding the state space of observed Markov processes is essential for advancing causal inference in a wide range of scientific fields. This paper demonstrates how the previously unknown state space can be reconstructed by exploring the spectrum of the time-delay embedding matrix derived from the autocorrelation sequence of the observed series. It also highlights that the eigenvector associated with the smallest eigenvalue can provide valuable insights into the hidden data generation process itself. The presented results provide a deeper understanding of the complex dynamics of Markov chains and hold promise for enhancing various scientific applications.