bluuebunny/crossref_metadata_2025 huggingface dataset:
A fuzzy logic and cross-layered optimization for effective congestion control in wireless sensor networks to improve efficiency and performance
Authors: Nithya S. , Maithili K. , Sathish Kumar T. , Nethani Shivakumar , Sharath M.N. , Gurnadha Gupta Koppuravuri , Bhuvaneswari G.
Published: March 2024

Wireless Sensor Networks (WSNs) are a fundamental component of the Internet of Things (IoT), used in diverse applications to detect environmental conditions and send information to the Internet. WSNs are susceptible to congestion issues, leading to increased packet loss, extended delays, and reduced throughput. This research introduces a Fuzzy Logic-based Cross-Layered Optimization Model (FL-CLOM) for WSNs to tackle the problem. FL-CLOM is developed by including the signal-to-noise ratio of the wireless channels in the Transmission Control Protocol (TCP) approach, bridging the transmission layer and Media Access Control (MAC) layer. A fuzzy logic system is created by integrating fuzzy control with congestion control to dynamically manage the queue size in crowded nodes and minimize the effects of external uncertainties. Various simulations were conducted using MATLAB and NS-2.34 to compare the suggested FL-CLOM to conventional methods. The results indicate that FL-CLOM efficiently adjusts to queue size changes and demonstrates rapid convergence, reduced average delay, reduced packet loss, and increased throughput.
Deep learning-based brain tumor detection: An MRI segmentation approach
Authors: Swathi V.N.V.L.S. , Sinduja K. , Ravi Kumar V. , Mahendar A. , Prasad Gollanapalli V. , Samya Banoth
Published: March 2024

The detection and segmentation of brain tumors from magnetic resonance imaging (MRI) scans are crucial for diagnosing, planning treatments, and monitoring patients with neurological disorders. This abstract provides a comprehensive overview of deep learning-based methods for detecting brain tumors, focusing on techniques for segmenting MRI images. Deep learning models, particularly convolutional neural networks (CNNs), have achieved impressive results in accurately segmenting brain tumors by learning distinctive features directly from the image data. Various CNN architectures, such as U-Net, DeepMedic, and 3D convolutional networks, have been specifically designed to address the challenges of brain tumor segmentation, including tumor heterogeneity, irregular shapes, and varying sizes. Additionally, the integration of multimodal MRI data, such as T1-weighted, T2-weighted, and FLAIR images, has enhanced the robustness and accuracy of deep learning models for brain tumor detection. This abstract discusses the significant advancements, challenges, and future directions in deep learning-based brain tumor detection, emphasizing the potential of MRI segmentation techniques to support clinicians in early diagnosis and personalized treatment planning for patients with brain tumors.
Exploration of image level classification based on semantic segmentation
Authors: Santhosh Kumar Ch.N. , Pavan Kumar P. , Lakshmi Deepthi N. , Aswani Reddy P. , Sujana Y.
Published: March 2024

Semantic segmentation is a fundamental computer vision task where an image is divided into segments, with each segment assigned a class label based on its visual content. The objective is to achieve a pixel-level understanding of the image, enhancing machines' ability to comprehend and interpret visual scenes. This technique finds utility across diverse domains such as autonomous driving, medical image analysis, scene comprehension, and image editing, among others. Traditional per-pixel classification methods often encounter challenges related to class imbalances within segmentation datasets. To address this, a novel approach has been proposed, leveraging human-provided hints or auxiliary training signals derived from contextual modeling in segmentation. Human-in-the-loop techniques are employed to validate subtasks, correcting segmentation errors and enhancing mean Intersection over Union (mIoU) metrics without the need for additional trained parameters.
Machine learning approaches for fault detection in renewable microgrids
Authors: Dutt Amit , Karuna G.
Published: March 2024

This study focuses on investigating and using machine learning (ML) methods to identify faults in renewable microgrids. It highlights the difficulties and intricacies associated with these dynamic energy systems. The examination of real-world data obtained from solar and wind power production, battery storage status, fault signals, and machine learning model performance highlights the complex nature of fault detection techniques in renewable microgrids. An analysis of data on renewable energy production demonstrates oscillations in the outputs of solar and wind power, highlighting differences of about 5-10% across certain time periods, thereby illustrating the intermittent characteristics of renewable energy sources. Simultaneously, the energy stored in batteries inside the microgrid shows a progressive decrease of about 3-5% in stored energy levels across time intervals, indicating possible consequences for the stability of the system. The fault detection signals display erratic patterns, which emphasize the intricacies involved in finding and categorizing issues inside the system. The assessment of machine learning models, which includes both supervised and unsupervised learning methods, reveals many performance measures. Supervised models provide greater accuracy rates, often ranging from 85% to 90%. However, they are prone to occasional misclassifications. In contrast, unsupervised models provide a moderate level of accuracy, often ranging from 75% to 80%. They exhibit flexibility in detecting faults, but their precision is limited. The study highlights the need of using a combination of supervised and unsupervised machine learning models to improve the accuracy of fault detection in renewable microgrids. These results provide valuable understanding of the intricacies and difficulties of fault detection procedures, which may lead to further progress in improving the dependability and durability of renewable microgrid systems.
Production écrite et ponctuation : étude comparative entre des élèves de début de primaire brésiliens et français
Authors: Calil Eduardo , Paolacci Véronique , Amorim Kall Anne , Felipeto Cristina
Published: March 2024

Cet article analyse les marques de ponctuation (MP) dans des histoires inventées par des élèves de 6 ans de deux classes : l’une brésilienne, l’autre française. Les deux professeures ont demandé aux élèves de leurs classes, organisés en binôme, de produire des récits. Douze manuscrits (M) ont été sélectionnés auprès de deux dyades de chaque pays (MBR, Manuscrits brésiliens et MFR, Manuscrits français). Notre analyse a pris en compte : a) la relation entre le nombre de mots et le nombre de marques de ponctuation; b) les types et les positions des MP. Dans les MBR, nous relevons une MP pour cinquante-cinq mots. Dans les MFR, la moyenne était d’une MP pour 5 mots. Dans les MBR, une majuscule et un point délimitent le début et la fin de l’histoire. Dans les MFR, placées tout au long du récit, les MP sont variées : lettre majuscule, virgule, tiret, point d’interrogation et point. Ces différences indiquent que l’apprentissage de l’écriture semble être associé à la pratique de l’enseignement, à l’approche didactique et aux méthodes de lecture.
Empreintes syntaxiques : des procédés pour affecter du lexique et développer les textes (élèves de 8 à 11 ans)
Authors: Roubaud Marie-Noëlle
Published: March 2024

Notre recherche porte sur l’analyse linguistique des productions d’élèves de 8 à 11 ans : l’étude concerne 900 textes narratifs. Nous nous sommes demandé comment de jeunes enfants s’y prenaient pour développer leur texte, pour l’épaissir. Nous avons cherché des traces de mécanismes fondamentaux d’élaboration langagière en rassemblant des recherches portant sur un phénomène linguistique particulier (comme l’énumération, la spécification…). C’est cette approche qui nous a permis de construire un répertoire de procédés syntaxiques ayant pour effet d’expanser le texte de l’élève. L’analyse du corpus montre en effet que les jeunes scripteurs utilisent les deux axes du langage : l’axe paradigmatique avec l’énumération, la dénomination, la retouche et l’axe syntagmatique avec la spécification et l’extension. Ces procédés amènent les élèves à faire défiler du lexique pour lister, détailler, préciser ou encore pour enchainer des séquences discursives. Leur usage indique chez les élèves des compétences syntaxiques déjà-là. Par ricochet, la recherche questionne l’enseignement et la formation : en premier lieu, elle réoriente le regard de l’enseignant sur ces empreintes syntaxiques et leur fonctionnement et ensuite, elle réinterroge la place de la littérature et de l’oral pour la constitution de modèles linguistiques.
“Maybe you need to do something about it”: challenges in global environmental change research with and within local communities
Authors: Roos Roxana
Published: March 2024

Research on issues such as adapting to rapid environmental change should include indigenous and local people in developing more robust and inclusive diagnoses and responses. Various studies indicate that such projects may face challenges. Researchers touch on these in papers where they reflect on their own work, but to a lesser extent in their empirical papers. Based on interviews with, and articles by, a varied sample of 15 researchers who work with local or indigenous peoples around the globe, I identified the challenges they face and how they deal with them. Thematic analysis of interview transcripts revealed eight themes: (1) external pressure, (2) engaging local people, (3) relevance of projects, (4) prior negative experiences, (5) cultural, historical, and geographical differences, (6) language challenges, (7) payment for participation, and (8) diverging epistemic cultures. Respondents’ statements in all themes contain reflections displaying care, consideration, or responsibility for the projects and the local people they involve. This links the challenges with everyday ethics. Analysis of scientific papers written by the respondents showed that they hardly write about the challenges they face, whereby neither local participants nor other readers of these texts are actively informed by and engaged in critical-reflective discussions about the challenges arising during the research and the strategies used to deal with them. The research community has a responsibility to remedy this shortcoming: in their papers, authors should discuss the main challenges faced and develop, describe, and promulgate strategies for dealing with them.
QuTree: A tree tensor network package
Authors: Ellerbrock Roman , Johnson K. Grace , Seritan Stefan , Hoppe Hannes , Zhang J. H. , Lenzen Tim , Weike Thomas , Manthe Uwe , Martínez Todd J.
Published: March 2024

We present QuTree, a C++ library for tree tensor network approaches. QuTree provides class structures for tensors, tensor trees, and related linear algebra functions that facilitate the fast development of tree tensor network approaches such as the multilayer multiconfigurational time-dependent Hartree approach or the density matrix renormalization group approach and its various extensions. We investigate the efficiency of relevant tensor and tensor network operations and show that the overhead for managing the network structure is negligible, even in cases with a million leaves and small tensors. QuTree focuses on providing simple, high-level routines while retaining easy access to the backend to facilitate novel developments. We demonstrate the capabilities of the package by computing the eigenstates of coupled harmonic oscillator Hamiltonians and performing random circuit simulations on a virtual quantum computer.
Fabrication of quantum emitters in aluminum nitride by Al-ion implantation and thermal annealing
Authors: Nieto Hernández E. , Yağcı H. B. , Pugliese V. , Aprà P. , Cannon J. K. , Bishop S. G. , Hadden J. , Ditalia Tchernij S. , Olivero P. , Bennett A. J. , Forneris J.
Published: March 2024

Single-photon emitters (SPEs) within wide-bandgap materials represent an appealing platform for the development of single-photon sources operating at room temperatures. Group III-nitrides have previously been shown to host efficient SPEs, which are attributed to deep energy levels within the large bandgap of the material, in a configuration that is similar to extensively investigated color centers in diamond. Anti-bunched emission from defect centers within gallium nitride and aluminum nitride (AlN) have been recently demonstrated. While such emitters are particularly interesting due to the compatibility of III-nitrides with cleanroom processes, the nature of such defects and the optimal conditions for forming them are not fully understood. Here, we investigate Al implantation on a commercial AlN epilayer through subsequent steps of thermal annealing and confocal microscopy measurements. We observe a fluence-dependent increase in the density of the emitters, resulting in the creation of ensembles at the maximum implantation fluence. Annealing at 600 °C results in the optimal yield in SPEs formation at the maximum fluence, while a significant reduction in SPE density is observed at lower fluences. These findings suggest that the mechanism of vacancy formation plays a key role in the creation of the emitters and open enticing perspectives in the defect engineering of SPEs in solid state.
Size-tunable and monodisperse lead sulfide quantum dots for broadband photodetectors
Authors: Fu Yujuan , Wang Yujiao , Zhao Jijie , Wen Shuai , Liu Huan , Li Qing , Gu Boao , Deng Lier
Published: March 2024

Lead sulfide quantum dots (PbS QDs) are used in broadband photodetectors due to their excellent size tunability, photosensitivity, and solution processability. However, due to the risk of Ostwald ripening, synthesizing high-quality PbS QDs with absorption peaks over 2000 nm with high monodispersity is a challenge. In this study, by controlling the molar ratio of Pb to S and the number of injections of S precursor, we successfully prepared large PbS QDs with an absorption peak at 2122 nm, corresponding to an average diameter of 11.42 nm, with a super-mono-dispersity of 5.50%. Broadband photodetectors ranging from visible light to short-wave infrared are prepared using the large PbS QDs, corresponding to a response rate of 5.98 mA/W at 1940 nm.
Surface optical phonon replica in photoluminescence spectroscopy of nitride nanostructures: Crystal structure and surface effects
Authors: Zhang L. , Chen Y. H. , Liu Q. , Liang Z. W. , Pang C. , Wang Q.
Published: March 2024

The surface optical (SO) phonon replica in photoluminescence (PL) spectroscopy of nitride nanowires (NWs) was theoretically investigated in this study. The dispersive relationships of SO phonon mode in anisotropic wurtzite (WZ) and isotropic zinc-blende (ZB) crystal structure NWs with circular and square cross sections (CSs) were derived within the framework of the dielectric continuum model. Based on the energy and momentum conservation laws, a constraint relationship between the frequency and wave-number was constructed for SO phonon-assisted excitonic PL spectra in the NW structure. By combining the dispersive and constraint relationships, the frequency and wave-number of the SO phonon replica in the PL spectra could be determined. The WZ and ZB crystal structures of nitride semiconductor were considered. The influences of surface factors including the CS shape, dielectric medium, and environment temperature on the frequency and photon wavelength of the band-edge emission of the SO phonon replica were studied in detail. Numerical results reveal that the crystal structure, surface factors, and environment temperature greatly affect the frequency and photon wavelength of the band-edge emission of the SO phonon replica. The calculated results for the photon wavelength agree well with the experimental values of the SO phonon replica in AlN NWs. The results of the dielectric effect obtained here are also supported by previous experimental and theoretical results for nitrides and other semiconductor NWs. The present theoretical scheme and numerical results can be used to analyze and design the SO phonon replica in PL spectra of nanostructures.
InGaAs/Si PIN photodetector with low interfacial recombination rates realized by wafer bonding with a polycrystalline Si interlayer
Authors: Jiao Jinlong , Ji Ruoyun , Yao Liqiang , Rao Yingjie , Ke Shaoying , Xu Jianfang , Zeng Yibo , Li Cheng , Lin Guangyang , Huang Wei , Chen Songyan
Published: March 2024

In this Letter, we proposed a robust InGaAs/Si bonded heterojunction by polycrystalline Si (poly-Si) and amorphous interlayers. The ultra-thin amorphous layer is induced through Ar plasma treatment. The synergism of poly-Si and amorphous interlayers effectively blocks the lattice mismatch and releases the interfacial thermal stress. A bubble- and defect-free bonding interface is achieved even if after annealing at 500 °C, demonstrating compatibility with high-temperature processes. The heavily doped poly-Si interlayer sweeps the electric field from the poly-Si layer and concentrates in the amorphous layer, rendering electron tunneling through the bonding interface and reducing the interfacial recombination rates. As a result, the bonded InGaAs/Si PIN photodetector harvests a saturated and low dark density of 0.26 mA/cm2 at −1 V and a high rectification ratio of 3.5 × 105 at ±1 V. Additionally, the non-optimized device achieves a high responsivity of 0.82 A/W at 1550 nm. These results indicate that the proposed bonding strategy provides a viable route to tackle the electronic, optical, and thermal barriers of integrating single-crystal InGaAs into Si platforms. This enables the photodetection of InGaAs/Si devices with a high signal-to-noise ratio.
Hysteresis-free voltage gating of the skyrmion
Authors: Kasagawa Mikito , Miki Soma , Hashimoto Ken Tanaka , Shimmura Akifumi , Ishikawa Ryo , Shiota Yoichi , Goto Minori , Nomura Hikaru , Suzuki Yoshishige
Published: March 2024

Magnetic skyrmions, which exhibit Brownian motion in solids, are considered good candidates as information carriers in devices, such as Brownian computers. Voltage control of skyrmions is essential for the ultralow power consumption of such devices. However, the gate operation must be realized with hysteresis-free voltage effects that are independent of ion migration for high-speed devices. In this study, we manipulated the skyrmion diffusion in a Ta|Co-Fe-B|Ta|MgO stacking structure by fabricating a device with a gate introducing an out-of-plane electrical field. Using feedback control, we rectified skyrmion diffusion in one direction, with the number of skyrmions passing through the gate wire from left to right N→ = 28 and from right to left N← = 43. Devices comprising Ta|Co-Fe-B|Pt|MgO junctions were fabricated, and a change in the density of skyrmions was observed upon the application of an out-of-plane electrical field. The creation or annihilation of skyrmions was dependent on the sign of the applied voltage. Furthermore, the skyrmions exhibited no hysteresis during the voltage sweep. Subsequently, the voltage dependence of the hysteresis loops in magneto-optical Kerr signals corresponding to the M–H curve was measured. However, no change was observed, nor was there any change in the saturated magnetization or perpendicular magnetic anisotropy. This result implied the voltage control of the Dzyaloshinskii–Moriya interaction.
Interfacial properties of the brine + carbon dioxide + oil + silica system
Authors: Yang Yafan , Narayanan Nair Arun Kumar , Lau Denvid , Sun Shuyu
Published: March 2024

Molecular dynamics simulations of the H2O + CO2 + aromatic hydrocarbon and H2O + CO2 + benzene + silica (hydrophilic) systems are performed to gain insights into CO2-enhanced oil recovery (EOR) processes. For comparison purposes, an overview of the previous simulation studies of the interfacial properties of the brine + CO2 + alkane + silica system is also presented. In general, the water contact angle (CA) of the H2O + CO2 + silica (hydrophilic) system increased with pressure and decreased with temperature. The CAs of the H2O + hydrocarbon + silica (hydrophilic) system are not significantly affected by temperature and pressure. The simulated CAs were in the ranges of about 58°–77° and 81°–93° for the H2O + hexane + silica (hydrophilic) and the H2O + aromatic hydrocarbon + silica (hydrophilic) systems, respectively. In general, these CAs were not significantly influenced by the addition of CO2. The simulated CAs were in the ranges of about 51.4°–95.0°, 69.1°–86.0°, and 72.0°–87.9° for the brine + CO2 + silica (hydrophilic), brine + hexane + silica (hydrophilic), and brine + CO2 + hexane + silica (hydrophilic) systems, respectively. All these CAs increased with increasing NaCl concentration. The adhesion tension of the brine + silica (hydrophilic) system in the presence of CO2 and/or hexane decreased with increasing salt concentration. The simulated CAs were in the range of about 117°–139° for the H2O + alkane + silica (hydrophobic) system. These CAs are increased by the addition of CO2. At high pressures, the distributions of H2O normal to the silica (hydrophobic) surface in the droplet region of the H2O + silica system were found to be strongly affected by the presence of CO2. These insights might be key for optimizing the performance of the miscible CO2 water-alternating-gas injection schemes widely used for EOR.
Tunable anomalous resistance and large magnetoresistance in HfTe5 by atom doping
Authors: Ning Jiai , Zhuge Minghua , An Hongyu , He Liang
Published: March 2024

The Dirac layered material HfTe5 renews significant interest due to its exotic band structure, leading to abundant transport properties, such as the anomaly resistance peak and its large magnetoresistance. Here, we prepared single crystals HfTe5 and Cr-doped CrxHf1−xTe5 and carried out their electrical transport measurements to explore the underlying physical origin of the anomaly resistance behavior and the large magnetoresistance. An anomalous resistance peak was observed in both intrinsic HfTe5 and the Cr-doped ones. Specifically, the peak temperature in the doped ones experiences an obvious shift from 52 to 34 K as the doping concentration x increases from 0 to 0.15, as well as the magnitude of the peak resistance is significantly enhanced. Furthermore, the magnetoresistance of CrxHf1−xTe5 is reduced by more than one order of magnitude compared with the intrinsic one. The significant reduction in magnetoresistance after Cr doping is attributed to the breaking of the balance between electron and hole carriers, which is confirmed by Kohler's plots. Meanwhile, in the sample where the magnetoresistance was minimized, we observed Shubnikov–de Haas oscillations. These observations illustrate that the large magnetoresistance is primarily contributed by the compensation of electrons and holes rather than the high mobility. Our findings provide valuable insight into how to engineer HfTe5 to achieve large magnetoresistance and its further applications in magnetic sensors and spintronics.
Quantum interference in a high-transition-temperature superconductor based on nanoslits on SrTiO3 substrate
Authors: Lin Jianxin , Huang Yicong , Zhou Han , Wu Yao , Zhang Haohui , Qin Shenghao , Peng Xiuyan , Wang Huachuan , Anahory Yonathan
Published: March 2024

The Josephson junction, a key component of superconducting quantum circuits, is much less mature, especially for the high-transition (high-Tc) temperature cuprate superconductors. Herein, we report on the realization of high-Tc Josephson junction based on nanoslits on a SrTiO3 substrate. We demonstrate the ability to manipulate the current–voltage characteristics of YBa2Cu3O7−x bridges continuously from superconducting current-dominated to Josephson junction behavior by changing the irradiation parameters of the focused Ga+ ion beam on a single-crystal SrTiO3 substrate. The periodic critical current that depends on the magnetic flux coupled into the superconducting quantum interference devices was observed, which exactly reflects the effects of quantum tunneling and flux quantization. To some extent, this weak link within the framework of the semiconductor manufacturing process shows the potential to provide a cost-effective, highly efficient, and reliable pathway for scaling up quantum mechanical superconducting circuits, which is promising for the fabrication process.
‘From Snowy River, up by Kosciusko’s side’: a virus, a beetle, and a PhD
Authors: Guy P. L.
Published: March 2024

A chance discovery early in 1980 led to a body of work on a virus and a rare species that lasted until the end of the decade. The discovery and characterisation of turnip yellow mosaic virus (TYMV-Cd) infecting one-fifth of the fragmented population of Cardamine robusta at Mt Kosciuszko, New South Wales, revealed a puzzle that remains unresolved. There is no clear explanation as to why there is a population of TYMV here in the Southern Hemisphere whose sequence has only diverged from Northern Hemisphere TYMV by a few percent. Adding to the mystery is the fact that TYMV-Cd only infects one of the rarest and geographically most restricted species in Australia, while it is surrounded by potential hosts known to be infected in the Northern Hemisphere. This article reviews research published on TYMV at Mt Kosciuszko during the 1980s and 1990s. While human agency cannot be ruled out, indications are that TYMV established without human intervention. The work is set in a historical context and highlights some of the changes around how plant virology is done.
The visual effect of wind turbines on property values is small and diminishing in space and time
Authors: Guo Wei , Wenz Leonie , Auffhammer Maximilian
Published: March 2024

Renewable power generation is the key to decarbonizing the electricity system. Wind power is the fastest-growing renewable source of electricity in the United States. However, expanding wind capacity often faces local opposition, partly due to a perceived visual disamenity from large wind turbines. Here, we provide a US-wide assessment of the externality costs of wind power generation through the visibility impact on property values. To this end, we create a database on wind turbine visibility, combining information on the site and height of each utility-scale turbine having fed power into the U.S. grid, with a high-resolution elevation map to account for the underlying topography of the landscape. Building on hedonic valuation theory, we statistically estimate the impact of wind turbine visibility on home values, informed by data from the majority of home sales in the United States since 1997. We find that on average, wind turbine visibility negatively affects home values in an economically and statistically significant way in close proximity (<5 miles/8 km). However, the effect diminishes over time and in distance and is indistinguishable from zero for larger distances and toward the end of our sample.
Climate change is poised to alter mountain stream ecosystem processes via organismal phenological shifts
Authors: Leathers Kyle , Herbst David , de Mendoza Guillermo , Doerschlag Gabriella , Ruhi Albert
Published: March 2024

Climate change is affecting the phenology of organisms and ecosystem processes across a wide range of environments. However, the links between organismal and ecosystem process change in complex communities remain uncertain. In snow-dominated watersheds, snowmelt in the spring and early summer, followed by a long low-flow period, characterizes the natural flow regime of streams and rivers. Here, we examined how earlier snowmelt will alter the phenology of mountain stream organisms and ecosystem processes via an outdoor mesocosm experiment in stream channels in the Eastern Sierra Nevada, California. The low-flow treatment, simulating a 3- to 6-wk earlier return to summer baseflow conditions projected under climate change scenarios in the region, increased water temperature and reduced biofilm production to respiration ratios by 32%. Additionally, most of the invertebrate species explaining community change (56% and 67% of the benthic and emergent taxa, respectively), changed in phenology as a consequence of the low-flow treatment. Further, emergent flux pulses of the dominant insect group (Chironomidae) almost doubled in magnitude, benefitting a generalist riparian predator. Changes in both invertebrate community structure (composition) and functioning (production) were mostly fine-scale, and response diversity at the community level stabilized seasonally aggregated responses. Our study illustrates how climate change in vulnerable mountain streams at the rain-to-snow transition is poised to alter the dynamics of stream food webs via fine-scale changes in phenology—leading to novel predator–prey “matches” or “mismatches” even when community structure and ecosystem processes appear stable at the annual scale.
High-entropy engineering with regulated defect structure and electron interaction tuning active sites for trifunctional electrocatalysis
Authors: Zou Xiaoxiao , Xie Jiyang , Mei Zhiyuan , Jing Qi , Sheng Xuelin , Zhang Conghui , Yang Yongxin , Sun Mengjiao , Ren Futong , Wang Lilian , He Tianwei , Kong Youchao , Guo Hong
Published: March 2024

High-entropy alloy nanoparticles (HEANs) possessing regulated defect structure and electron interaction exhibit a guideline for constructing multifunctional catalysts. However, the microstructure–activity relationship between active sites of HEANs for multifunctional electrocatalysts is rarely reported. In this work, HEANs distributed on multi-walled carbon nanotubes (HEAN/CNT) are prepared by Joule heating as an example to explain the mechanism of trifunctional electrocatalysis for oxygen reduction, oxygen evolution, and hydrogen evolution reaction. HEAN/CNT excels with unmatched stability, maintaining a 0.8V voltage window for 220 h in zinc–air batteries. Even after 20 h of water electrolysis, its performance remains undiminished, highlighting exceptional endurance and reliability. Moreover, the intrinsic characteristics of the defect structure and electron interaction for HEAN/CNT are investigated in detail. The electrocatalytic mechanism of trifunctional electrocatalysis of HEAN/CNT under different conditions is identified by in situ monitoring and theoretical calculation. Meanwhile, the electron interaction and adaptive regulation of active sites in the trifunctional electrocatalysis of HEANs were further verified by density functional theory. These findings could provide unique ideas for designing inexpensive multifunctional high-entropy electrocatalysts.
Mutant huntingtin protein induces MLH1 degradation, DNA hyperexcision, and cGAS–STING-dependent apoptosis
Authors: Sun Xiao , Liu Lu , Wu Chao , Li Xueying , Guo Jinzhen , Zhang Junqiu , Guan Junhong , Wang Nan , Gu Liya , Yang X. Willian , Li Guo-Min
Published: March 2024

Huntington’s disease (HD) is an inherited neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin (
HTT
) gene. The repeat-expanded
HTT
encodes a mutated HTT (mHTT), which is known to induce DNA double-strand breaks (DSBs), activation of the cGAS–STING pathway, and apoptosis in HD. However, the mechanism by which mHTT triggers these events is unknown. Here, we show that HTT interacts with both exonuclease 1 (Exo1) and MutLα (MLH1–PMS2), a negative regulator of Exo1. While the HTT–Exo1 interaction suppresses the Exo1-catalyzed DNA end resection during DSB repair, the HTT–MutLα interaction functions to stabilize MLH1. However, mHTT displays a significantly reduced interaction with Exo1 or MutLα, thereby losing the ability to regulate Exo1. Thus, cells expressing mHTT exhibit rapid MLH1 degradation and hyperactive DNA excision, which causes severe DNA damage and cytosolic DNA accumulation. This activates the cGAS–STING pathway to mediate apoptosis. Therefore, we have identified unique functions for both HTT and mHTT in modulating DNA repair and the cGAS–STING pathway-mediated apoptosis by interacting with MLH1. Our work elucidates the mechanism by which mHTT causes HD.
Phototransformation of achiral metasurfaces into handedness-selectable transient chiral media
Authors: Kim Andrew S. , Goswami Anjan , Taghinejad Mohammad , Cai Wenshan
Published: March 2024

Chirality is a geometric property describing the lack of mirror symmetry. This unique feature enables photonic spin-selectivity in light–matter interaction, which is of great significance in stereochemistry, drug development, quantum optics, and optical polarization control. The versatile control of optical geometry renders optical metamaterials as an effective platform for engineered chiral properties at prescribed spectral regimes. Unfortunately, geometry-imposed restrictions only allow one circular polarization state of photons to effectively interact with chiral meta-structures. This limitation motivates the idea of discovering alternative techniques for dynamically reconfiguring the chiroptical responses of metamaterials in a fast and facile manner. Here, we demonstrate an approach that enables optical, sub-picosecond conversion of achiral meta-structures to transient chiral media in the visible regime with desired handedness upon the inhomogeneous generation of plasmonic hot electrons. As a proof of concept, we utilize linearly polarized laser pulse to demonstrate near-complete conversion of spin sensitivity in an achiral meta-platform—a functionality yet achieved in a non-mechanical fashion. Owing to the generation, diffusion, and relaxation dynamics of hot electrons, the demonstrated technique for all-optical creation of chirality is inherently fast, opening new avenues for ultrafast spectro-temporal construction of chiral platforms with on-demand spin-selectivity.
GYOTO 2.0: a polarized relativistic ray-tracing code
Authors: Aimar N , Paumard T , Vincent F H , Gourgoulhon E , Perrin G
Published: March 2024

Polarized general-relativistic radiative transfer in the vicinity of black holes and other compact objects has become a crucial tool for probing the properties of relativistic astrophysics plasmas. Instruments like GRAVITY, the Event Horizon telescope, Atacama Large Millimeter/submillimeter Array, or Imaging x-ray Polarimetry Explorer make it very timely to develop such numerical frameworks. In this article, we present the polarized extension of the public ray-tracing code Gyoto, and offer a python notebook allowing to easily perform a first realistic computation. The code is very modular and allows to conveniently add extensions for the specific needs of the user. It is agnostic about the spacetime and can be used for arbitrary compact objects. We demonstrate the validity of the code by providing tests, and show in particular a perfect agreement with the ipole code. Our article also aims at pedagogically introducing all the relevant formalism in a self-contained manner.
Ion flow and dust charging at the sheath boundary in dusty plasma with an electron-emitting surface: applications to laboratory and lunar dusty plasmas
Authors: Basnet Suresh , Patel Amit , Bikram Thapa Shiva , Khanal Raju
Published: March 2024

In laboratory and space plasmas, the emission of electrons from the surface significantly affects the characteristics of the plasma sheath that forms at that surface, which is crucial to understanding the overall plasma-wall interaction mechanism. In this work, the collisional fluid model is used for laboratory dusty plasma, whereas the collisionless model is used for lunar dusty plasma. We have extended the Bohm sheath criterion for the formation of the stable plasma sheath due to electron emission from the surface, loss of ion flux, and the gas pressure of the collisional laboratory dusty plasmas. It is found that ion flow at the sheath boundary is considerably influenced by the concentration of electron emission, the ion loss term, and gas pressure. The evolution of the dust charge explicitly determines the magnitude of the ion flow at the sheath boundary. The plasma parameters adopted in the present case are reliable in laboratory and space dusty plasmas, especially the dusty plasma environment on the lunar surface. The lunar surface and dust grains on the Moon become electrically charged as a result of the interaction between solar wind plasma and photoemission electrons emitted from the lunar surface. In addition, the lunar plasma sheath characteristics, dust-charging process, and stable dust levitation in the sheath region have been studied.
The kinetic theory of cathode plasma expansion in a spatially non-uniform geometric configuration of a vacuum diode
Authors: Yao Jingfeng , Kozhevnikov Vasily , Igumnov Vladislav , Chu Zijia , Yuan Chengxun , Zhou Zhongxiang
Published: March 2024

This paper presents a theoretical explanation for the occurrence of anomalous ion acceleration in vacuum diodes, leading to the expansion of cathode plasma towards the anode, a characteristic phenomenon of vacuum breakdown. The explanation is derived from first principles based on equations of collisionless physical kinetics, using the example of an axisymmetric vacuum diode. The proposed theoretical interpretation convincingly demonstrates that the primary mechanism behind the anomalous ion acceleration of cathode plasma is the collisionless motion of ions in a self-consistent electric field.
Abundant optical soliton solutions for the stochastic fractional fokas system using bifurcation analysis
Authors: Mohammed Wael W , Cesarano Clemente , Elmandouh Adel A , Alqsair Ikbal , Sidaoui Rabeb , Alshammari Hessa W
Published: March 2024

In this study, the stochastic fractional Fokas system (SFFS) with M-truncated derivatives is considered. A certain wave transformation is applied to convert this system to a one-dimensional conservative Hamiltonian system. Based on the qualitative theory of dynamical systems, the bifurcation and phase portrait are examined. Utilizing the conserved quantity, we construct some new traveling wave solutions for the SFFS. Due to the fact that the Fokas system is used to explain nonlinear pulse transmission in mono-mode optical fibers, the given solutions may be applied to analyze an extensive variety of crucial physical phenomena. To clarify the effects of the M-truncated derivative and Wiener process, the dynamic behaviors of the various obtained solutions are depicted with 3-D and 2-D curves.
The effects of tungsten doping on the thermoelectric properties of Bi2O2Se
Authors: Li Buda , Qi Hangbo , Zhao Siqin , Li Menglu , Feng Shan , Zu Xiaotao , Qiao Liang , Xiao Haiyan
Published: March 2024

In this study, we investigate the effects of tungsten doping on the structural, electronic, and thermoelectric properties of Bi2O2Se using density functional theory combined with Boltzmann transport theory. As the tungsten is doped at Bi-site, the introduced additional electrons modify the electronic structure of Bi2O2Se significantly and lead to the metallic character of Bi2O2Se. Meanwhile, tungsten doping improves the electrical conductivity and power factor of Bi2O2Se, and optimizes the figure of merit ZT. This study demonstrates that tungsten doping is an effective method to modify the thermoelectric transport properties of Bi2O2Se.
Chemical vapor deposition-based synthesis of binder-free nanostructure α-MoO3 electrode material for PES devices
Authors: Raza A , Ali M , Ayub N , Atta S , Jawad M
Published: March 2024

Molybdenum-based metal oxides have succeeded in incredible consideration for supercapacitor applications due to their outstanding structural, morphological and electrochemical properties. Herein, a highly porous orthorhombic MoO3 (α-MoO3) nanobenzene like nanosheets are synthesized on nickel foam (Ni–F) via a simple and cost-effective chemical vapor deposition (CVD) technique. The x-ray diffraction (XRD) analysis confirmed the synthesis of nanostructured α-MoO3 having multi oriented diffraction planes. The surface morphology (SEM) analysis indicated that the entwined nanobenzene through nano-rods/particles is beneficial for good electrical conductivity hence the high electrochemical performance of synthesized α-MoO3. The electrochemical properties of synthesized α-MoO3 electrode material like cyclic voltammetry (CV), galvanostatic charging–discharging (GCD) and electrochemical impedance spectroscopy (EIS) are analyzed using a three-electrode electrochemical workstation in 2 M KOH electrolyte solution. The synthesized α-MoO3 pseudocapacitor presented a maximum specific capacitance of 3206 F g−1 at a current density of 1 A/g. Moreover, α-MoO3 exhibits a cyclic stability of about 99.95% after 3000 cycles, high energy density (111 Wh kg−1), power density (2500 W kg−1) and negligible charge transfer resistance (0.6 ohms), indicating that it can serve as an excellent electrode material for supercapacitors. The Power law and Dunn’s model simulations also confirmed that the excellent electrochemical performance of synthesized α-MoO3 electrode material is contributed by capacitive as well as diffusion-controlled behavior.
On thermal fluctuations and quantum regularities of

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gravity black holes with constant topological Euler density in nonlinear electrodynamics
Authors: Mangut Mert , Gürtuğ Özay , Sakallı İzzet
Published: March 2024

We discuss the corrected thermodynamics and naked singularity structure of the topological static spherically symmetric solution in

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- gravity coupled with Born-Infeld—like nonlinear electrodynamics. Solutions admitting black holes with constant topological Euler density is analyzed in view of various thermodynamical variables. The inclusion of logarithmic correction to the entropy is extended to the other thermodynamical variables and the contribution of corrected variables are displayed on various plots. The stability of black hole under the effect of thermal variables is also studied. As a second scope of this study, solutions admitting timelike naked singularity are probed with bosonic and fermionic quantum wave packets to see if the singularity is quantum mechanically regular or not. In this context, the evolution of these probes remains well-defined if the corresponding spatial Hamiltonian operator is essentially self-adjoint. Our calculations reveal that when the singularity is probed with specific wave modes involving spin—0 and spin—1/2 quantum wave packets, the corresponding wave operators turn out to be essentially self-adjoint, which in turn implies unique well-defined time evolution.
Numerical investigation into turbulent drag reduction via the application of pufferfish spine-inspired cone microstructures in Suboff models
Authors: Zhao Lei , Zhu Dongpo , Feng Xiaoming , Chen Bo , Tian Guizhong , Wei Kairan , Song Zhiyuan
Published: March 2024

The effective reduction of seawater drag is pivotal in enhancing the speed and minimizing the energy consumption of submarines, which has significant implications in the fields of energy and defense. Surface bionics has emerged as one of the leading techniques for drag reduction. Current research primarily focuses on replicating the groove-like structures observed on shark skins and the flexible properties of dolphin skins. However, the application of cone microstructures on submarine surfaces remains relatively underexplored. In this study, a novel arrangement of bionic drag-reducing microstructures is employed to modify the turbulence structure surrounding the submarine by incorporating bionic cone microstructures at both the front and rear ends of the submarine. Numerical simulations were performed using the SST k-ω turbulence model to evaluate the impact of these frontal microstructures on drag reduction under varying Reynolds numbers, spacings, and positions, as well as the tail microstructures’ effect at different Reynolds numbers, heights, and circumferential separation angles. The findings reveal that positioning microstructures at the submarine’s head increases the drag reduction rate proportionally with the distance from the apex, displaying an inverse relationship between spacing and drag reduction rate. Conversely, an increase in cone separation angle at the tail leads to a decrease in the overall drag reduction rate. At the same time, an inverse proportionality is observed between cone height and drag reduction rate. This suggests that cone microstructures play a dual role: mitigating friction drag greatly and augmenting pressure drag, thereby achieving overall drag reduction. Moreover, these cone microstructures disrupt eddy currents within the boundary layer surrounding the submarine, restraining the propagation of turbulent momentum transfer in both the head and tail regions. This research not only pioneers a novel drag reduction strategy for underwater vehicles but also sparks new avenues for their optimized surface design.
Investigating the potential of carbon nitride as a new sensing material for NOx (N2O, N2O3, N2O4, and N2O5): a DFT study
Authors: Nadeem Hafsah , Ahmed Hina , Saleem Uzma , Jamil Rabia , Ayub Khurshid , Alsalhi Sarah A , Iqbal Javed
Published: March 2024

Herein, DFT study was used to investigate the carbon nitride C6N8 as a potential detector of noxious gases, specifically nitrous oxide (N2O), dinitrogen tri-oxide (N2O3), dinitrogen tetra-oxide (N2O4), and dinitrogen penta-oxide. (N2O5). The Physiosorption process was notified after the adsorption of N2O (−12.6463 kJ mol–1), N2O3 (−40.1466 kJ mol–1), N2O4 (−23.8512 kJ mol–1), and N2O5 (−29.7947 kJ mol−1) on C6N8. The adsorption behavior shows weak interactions in the complexes which depicts the stability trend as N2O3@C6N8 > N2O5@C6N8 > N2O4@C6N8 > N2O@C6N8. Various analyses and techniques were employed to evaluate the sensing capability. Electronic parameters such as FMO, ELF, NBO, UV-visible spectrum, and DOS were performed to notify the detectable change in the sensing surface after the adsorption of the gases being studied. The existence of non-covalent interactions was confirmed by Symmetry Adopted Perturbation Theory (SAPT0), QTAIM, NCI, and IRI plots. Moreover, SAPT0 confirmed the greater contribution of Edispersion in N2O@C6N8. ESP (MEPs) visualization confirmed the interactions, as the nitrogen atoms of the surface are electron dense regions for the analytes to attack. Chemical stability and selectivity were evidenced by the stability parameters and the formation of new states in the DOS spectrum, respectively. Significant recovery time performance was observed after evaluating the recovery of analyte@C6N8 complexes at an appropriate temperature. These results suggest C6N8 theoretically as a potentially active sensing surface and it will enhance the interest of the experimental researchers in fabricating a sensing device using this material for the determination of even minute concentrations of the toxic gases.