bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing pathways of seafood access in small island developing states
Authors: Seto Katherine L. , Friedman Whitney R. , Eurich Jacob G. , Gephart Jessica A. , Zamborain-Mason Jessica , Sharp Michael , Aram Erietera , Tekaieti Aritita , Tekiau Aranteiti , Golden Christopher D.
Published: February 2024

Ensuring healthy and sustainable food systems in increasing social, economic, and ecological change is a key global priority to protect human and environmental health. Seafood is an essential component of these food systems and a critical source of nutrients, especially in coastal communities. However, despite rapid transformations in aquatic food systems, and our urgent need to understand them, there is a dearth of data connecting harvested food production to actualized food consumption. Many analyses suggest institutional, legal, or technological innovations to improve food systems, but few have analyzed the pathways through which people already gain access to nutritious food. Here, using a random forest model and cluster analysis of a nationally representative data set from Kiribati, we operationalize access theory to trace the flows of consumptive benefit in a fisheries-based food system. We demonstrate that the market access mechanism is the key mechanism mediating seafood access in Kiribati, but importantly, the highest seafood consumption households showed lower market access, pointing to the importance of non-market acquisition (e.g., home production and gifting). We reveal six distinct household strategies that employ different sets of access mechanisms to ensure high levels of local seafood consumption in different contexts. We demonstrate the impacts of these strategies on the composition of household seafoods consumed, stressing the need to support these existing successful strategies. Finally, we point to key policy and management insights (e.g., improved infrastructure, shifts in species management) that may be more effective in reinforcing these existing pathways than commonly proposed food system interventions.
Puromycin reveals a distinct conformation of neuronal ribosomes
Authors: Anadolu Mina N. , Sun Jingyu , Li Jewel T.-Y. , Graber Tyson E. , Ortega Joaquin , Sossin Wayne S.
Published: February 2024

Puromycin is covalently added to the nascent chain of proteins by the peptidyl transferase activity of the ribosome and the dissociation of the puromycylated peptide typically follows this event. It was postulated that blocking the translocation of the ribosome with emetine could retain the puromycylated peptide on the ribosome, but evidence against this has recently been published [Hobson
et al.
,
Elife
9
, e60048 (2020); and Enam
et al.
,
Elife
9
, e60303 (2020)]. In neurons, puromycylated nascent chains remain in the ribosome even in the absence of emetine, yet direct evidence for this has been lacking. Using biochemistry and cryoelectron microscopy, we show that the puromycylated peptides remain in the ribosome exit channel in the large subunit in a subset of neuronal ribosomes stalled in the hybrid state. These results validate previous experiments to localize stalled polysomes in neurons and provide insight into how neuronal ribosomes are stalled. Moreover, in these hybrid-state neuronal ribosomes, anisomycin, which usually blocks puromycylation, competes poorly with puromycin in the puromycylation reaction, allowing a simple assay to determine the proportion of nascent chains that are stalled in this state. In early hippocampal neuronal cultures, over 50% of all nascent peptides are found in these stalled polysomes. These results provide insights into the stalling mechanisms of neuronal ribosomes and suggest that puromycylated peptides can be used to reveal subcellular sites of hybrid-state stalled ribosomes in neurons.
Learning beyond-pairwise interactions enables the bottom–up prediction of microbial community structure
Authors: Ishizawa Hidehiro , Tashiro Yosuke , Inoue Daisuke , Ike Michihiko , Futamata Hiroyuki
Published: February 2024

Understanding the assembly of multispecies microbial communities represents a significant challenge in ecology and has wide applications in agriculture, wastewater treatment, and human healthcare domains. Traditionally, studies on the microbial community assembly focused on analyzing pairwise relationships among species; however, neglecting higher-order interactions, i.e., the change of pairwise relationships in the community context, may lead to substantial deviation from reality. Herein, we have proposed a simple framework that incorporates higher-order interactions into a bottom–up prediction of the microbial community assembly and examined its accuracy using a seven-member synthetic bacterial community on a host plant, duckweed. Although the synthetic community exhibited emergent properties that cannot be predicted from pairwise coculturing results, our results demonstrated that incorporating information from three-member combinations allows the acceptable prediction of the community structure and actual interaction forces within it. This reflects that the occurrence of higher-order effects follows consistent patterns, which can be predicted even from trio combinations, the smallest unit of higher-order interactions. These results highlight the possibility of predicting, explaining, and understanding the microbial community structure from the bottom–up by learning interspecies interactions from simple beyond-pairwise combinations.
S
1
basic leucine zipper transcription factors shape plant architecture by controlling C/N partitioning to apical and lateral organs
Authors: Kreisz Philipp , Hellens Alicia M. , Fröschel Christian , Krischke Markus , Maag Daniel , Feil Regina , Wildenhain Theresa , Draken Jan , Braune Gabriel , Erdelitsch Leon , Cecchino Laura , Wagner Tobias C. , Ache Peter , Mueller Martin J. , Becker Dirk , Lunn John E. , Hanson Johannes , Beveridge Christine A. , Fichtner Franziska , Barbier Francois F. , Weiste Christoph
Published: February 2024

Plants tightly control growth of their lateral organs, which led to the concept of apical dominance. However, outgrowth of the dormant lateral primordia is sensitive to the plant’s nutritional status, resulting in an immense plasticity in plant architecture. While the impact of hormonal regulation on apical dominance is well characterized, the prime importance of sugar signaling to unleash lateral organ formation has just recently emerged. Here, we aimed to identify transcriptional regulators, which control the trade-off between growth of apical versus lateral organs. Making use of locally inducible gain-of-function as well as single and higher-order loss-of-function approaches of the sugar-responsive S
1
-basic-leucine-zipper (S
1
-bZIP) transcription factors, we disclosed their largely redundant function in establishing apical growth dominance. Consistently, comprehensive phenotypical and analytical studies of S
1
-bZIP mutants show a clear shift of sugar and organic nitrogen (N) allocation from apical to lateral organs, coinciding with strong lateral organ outgrowth. Tissue-specific transcriptomics reveal specific clade III
SWEET
sugar transporters, crucial for long-distance sugar transport to apical sinks and the glutaminase
GLUTAMINE AMIDO-TRANSFERASE 1_2.1
, involved in N homeostasis, as direct S
1
-bZIP targets, linking the architectural and metabolic mutant phenotypes to downstream gene regulation. Based on these results, we propose that S
1
-bZIPs control carbohydrate (C) partitioning from source leaves to apical organs and tune systemic N supply to restrict lateral organ formation by C/N depletion. Knowledge of the underlying mechanisms controlling plant C/N partitioning is of pivotal importance for breeding strategies to generate plants with desired architectural and nutritional characteristics.
Real-time tracking of electron transfer at catalytically active interfaces in lithium-ion batteries
Authors: Li Hongsen , Hu Zhengqiang , Zuo Fengkai , Li Yuhao , Liu Minhui , Liu Hengjun , Li Yadong , Li Qiang , Ding Yu , Wang Yaqun , Zhu Yue , Yu Guihua , Maier Joachim
Published: February 2024

Transition metals and related compounds are known to exhibit high catalytic activities in various electrochemical reactions thanks to their intriguing electronic structures. What is lesser known is their unique role in storing and transferring electrons in battery electrodes which undergo additional solid-state conversion reactions and exhibit substantially large extra capacities. Here, a full dynamic picture depicting the generation and evolution of electrochemical interfaces in the presence of metallic nanoparticles is revealed in a model CoCO
3
/Li battery via an in situ magnetometry technique. Beyond the conventional reduction to a Li
2
CO
3
/Co mixture under battery operation, further decomposition of Li
2
CO
3
is realized by releasing interfacially stored electrons from its adjacent Co nanoparticles, whose subtle variation in the electronic structure during this charge transfer process has been monitored in real time. The findings in this work may not only inspire future development of advanced electrode materials for next-generation energy storage devices but also open up opportunities in achieving in situ monitoring of important electrocatalytic processes in many energy conversion and storage systems.
Rearranging equations to develop physics reasoning
Authors: Kapodistrias Anastasios , Airey John
Published: February 2024

Researchers generally agree that physics experts use mathematics in a way that blends mathematical knowledge with physics intuition. However, the use of mathematics in physics education has traditionally tended to focus more on the computational aspect (manipulating mathematical operations to get numerical solutions) to the detriment of building conceptual understanding and physics intuition. Several solutions to this problem have been suggested; some authors have suggested building conceptual understanding before mathematics is introduced, while others have argued for the inseparability of the two, claiming instead that mathematics and conceptual physics need to be taught simultaneously. Although there is a body of work looking into how students employ mathematical reasoning when working with equations, the specifics of how physics experts use mathematics blended with physics intuition remain relatively underexplored. In this paper, we describe some components of this blending, by analyzing how physicists perform the rearrangement of a specific equation in cosmology. Our data consist of five consecutive forms of rearrangement of the equation, as observed in three separate higher education cosmology courses. This rearrangement was analyzed from a conceptual reasoning perspective using Sherin’s framework of symbolic forms. Our analysis clearly demonstrates how the number of potential symbolic forms associated with each subsequent rearrangement of the equation decreases as we move from line to line. Drawing on this result, we suggest an underlying mechanism for how physicists reason with equations. This mechanism seems to consist of three components: narrowing down meaning potential, moving aspects between the background and the foreground and purposefully transforming the equation according to the discipline’s questions of interest. In the discussion section we highlight the potential that our work has for generalizability and how being aware of the components of this underlying mechanism can potentially affect physics teachers’ practice when using mathematics in the physics classroom.
Experimenting with light at the 6th European Physics Olympiad
Authors: Stergar Jošt , Čopar Simon
Published: February 2024

A good experimental task for a high school physics competition requires an interesting and relatable topic, careful testing, and meeting constraints of time, budget, and curriculum. This article presents the experimental task from the European Physics Olympiad in the year 2022. The students explored the properties of light sources, such as their colour temperature, angular light distribution, efficacy, and heating. The task was stated without explicit instructions, inviting the students to devise their own approach to measurement and data processing. The original task was designed for a level slightly above the European high-school curriculum, so parts of it can be directly used as a lab exercise at a university level or simplified and given more specific instructions for inclusion in high school level education.
Blade emitters for atmospheric ionic thrusters
Authors: Belan M , Baldo J , Kahol O , Montenero D
Published: February 2024

In the field of atmospheric ionic thrusters, the objective of this work is to evaluate the possibility of an alternative ionic emitter to the traditional thin wire emitter, in order to overcome the technical issues of the EHD technology related to the fragility of the wires and to make it more suitable to applications outside the laboratory. For the presented experiments, emitters in the form of metallic blades have been produced. These were tested while varying the geometric parameters of both the emitters themselves and of the thruster configuration. Through this measurement campaign, the electrical characteristics, as well as the feasibility and the performances of the new proposed solutions have been evaluated and compared with wire emitters. Results indicate that the blade emitters can work as alternative emitters, however the performance of the present prototypes does not reach that of wire emitters and therefore further research is needed in order to make them a valid alternative.
Entropy driven incommensurate structures in the frustrated kagome staircase Co3V2O8
Authors: S Helton Joel , Rogado Nyrissa , J Cava Robert , W Lynn Jeffrey
Published: February 2024

Co3V2O8 features spin-3/2 moments arrayed on a kagome staircase lattice. A spin density wave with a continuously evolving propagation vector of

k
⃗

=
(
0
,
δ
,
0
)

, showing both incommensurate states and multiple commensurate lock-ins, is observed at temperatures above the ferromagnetic ground state. Previous work has suggested that this changing propagation vector could be driven by changes in exchange interactions due to Co atom displacements. We present a straightforward model showing that a Hamiltonian with competing (but temperature independent) interactions can semi-quantitatively reproduce this behavior using a mean field approximation. The simulated spin density wave magnetic structures feature buckled kagome planes that are either ferromagnetically or antiferromagnetically ordered. Propagation vectors that differ from

δ
=
1

/

2

will have multiple different ways of arranging these ferromagnetic layers that have very similar energies. This classical stacking entropy appears to be crucial in stabilizing the temperature-dependent propagation vector.
Advancements in multiferroic, dielectric, and impedance properties of copper–yttrium co-doped cobalt ferrite for hydroelectric cell applications
Authors: Jain Prachi , Shankar S , Thakur O P
Published: February 2024

This paper explores yttrium and copper co-doped cobalt ferrite [Co1−x
Cu
x
Fe1.85Y0.15O4] synthesized via the sol–gel auto-combustion route (0.0 ⩽ x ⩽ 0.08). Investigating the impact of co-dopants on CoFe2O4, the study reveals altered cation distribution affecting the structure, multiferroic, and electrical properties. X-ray diffraction studies show nanocrystalline co-doped cobalt ferrites with lattice expansion and smaller grains due to Cu–Y co-doping. Fourier transform infrared spectroscopy confirms inverse spinel family classification with tetrahedral lattice shrinkage. Field emission scanning electron microscopy indicates a grain size of approximately 0.12 μm. Ferroelectric analysis reveals a peak saturation polarization of 23.42 μC cm−2 for 8% copper doping, attributed to increased Fe3+ ions at tetrahedral sites. Saturation magnetization peaks at 54.4706 emu g−1 for 2% Cu2+ ion substitution [Co0.98Cu0.02Fe1.85Y0.15O4] and decreases to 37.09 emu g−1 for 4% Cu substitution due to irregular iron atom distribution at tetrahedral sites. Dielectric studies uncover Maxwell–Wagner polarization and high resistance in grain and grain boundaries using impedance spectroscopy. Fabricated hydroelectric cells exhibit improved ionic diffusion, suggesting their use in potential hydroelectric cell applications.
Band gap characteristics of new composite multiple locally resonant phononic crystal metamaterial
Authors: Xiao Peng , Miao Linchang , Zheng Haizhong , Lei Lijian
Published: February 2024

Locally resonant phononic crystal (LRPC) exhibit elastic wave band gap characteristics within a specific low-frequency range, but their band gap width is relatively narrow, which has certain limitations in practical engineering applications. In order to open a lower frequency band gap and broaden the band gap range, this paper proposes a new composite multiple locally resonant phononic crystal (CMLRPC). Firstly, the band structure of the CMLRPC is calculated by using the finite element method, and then the formation mechanism of the band gap of the CMLRPC is studied by analyzing its vibration mode, and the band gap width is expanded by adjusting the size of the single primitive cell in the supercell model of the CMLRPC. Secondly, an equivalent mass-spring system model for CMLRPC is established to calculate the starting frequency and cut-off frequency of the band gap, and the calculated results are in good agreement with the finite element calculation. Finally, the frequency response function of the CMLRPC is calculated and its attenuation characteristics are analyzed. Within the band gap frequency range, the attenuation values of the CMLRPC are mostly above 20 dB, indicating a good attenuation effect. Compared with traditional LRPC, this new CMLRPC opens multiple band gaps in the frequency range of 200 Hz, with a wider band gap width and better attenuation effect. In addition, considering both the contact between single primitive cell and the adjustment of their spacing in the supercell model of the CMLRPC, lower and wider band gap can be obtained. The research results of this paper provide a new design idea and method for obtaining low-frequency band gap in LRPC, and can provide reference for the design of vibration reduction and isolation structures in the field of low-frequency vibration control.
Improve exploration in deep reinforcement learning for UAV path planning using state and action entropy
Authors: Lv Hui , Chen Yadong , Li Shibo , Zhu Baolong , Li Min
Published: February 2024

Despite being a widely adopted development framework for unmanned aerial vehicle (UAV), deep reinforcement learning is often considered sample inefficient. Particularly, UAV struggles to fully explore the state and action space in environments with sparse rewards. While some exploration algorithms have been proposed to overcome the challenge of sparse rewards, they are not specifically tailored for UAV platform. Consequently, applying those algorithms to UAV path planning may lead to problems such as unstable training processes and neglect of action space comprehension, possibly causing negative impacts on the path planning results. To address the problem of sparse rewards in UAV path planning, we propose an information-theoretic exploration algorithm, Entropy Explorer (EE), specifically for UAV platform. The proposed EE generates intrinsic rewards based on state entropy and action entropy to compensate for the scarcity of extrinsic rewards. To further improve sampling efficiency, a framework integrating EE and Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithms is proposed. Finally, the TD3-EE algorithm is tested in AirSim and compared against benchmarking algorithms. The simulation outcomes manifest that TD3-EE effectively stimulates the UAV to comprehensively explore both state and action spaces, thereby attaining superior performance compared to the benchmark algorithms in the realm of path planning.
Air conditioning compressor crankshaft roundness measurement based on a laser profiler
Authors: Liang Jie , Sun Zhenwei
Published: February 2024

Crankshafts are key components of air conditioning compressors. The good roundness of a crankshaft has positive effects on the operating stability, service life, working efficiency, and noise radiation of the compressor. This study proposes a line point cloud data merging method for measuring crankshaft roundness using a laser profiler. First, a crankshaft roundness measurement system for air conditioning compressors is developed, and a high-accuracy 2D laser displacement sensor is employed to collect the line point cloud data. Second, the steps of the merging method are divided into two parts: (1) the radial merging to eliminate the effects of eccentricity; (2) the circumferential merging to remove overlapping data points of two adjacent profiles. Then, a pin gauge is used to select the point cloud region of the profile line for data merging. Experimental results show that the measurement repeatability of the proposed system can be controlled at the micrometer level. Besides, the roundness measured from the merged data is very close to the roundness measuring instrument measurements, which verifies the accuracy of the measurement system and the validity of the line point data merging algorithm.
Real-time hollow defect detection in tiles using on-device tiny machine learning
Authors: Lin Tzu-Hsuan , Chang Chien-Ta , Zhuang Ting-Han , Putranto Alan
Published: February 2024

This study addresses the challenge of subsurface defect detection in floor tiles for quality control in residential construction. To overcome the limitations of traditional inspection methods and the complexities associated with existing artificial intelligence (AI)-based approaches, we have developed the AI diagnostic Stick (AID-Stick), a novel tool designed to advance the field of tile defect detection. This innovative tool integrates an embedded machine-learning framework, leveraging convolutional neural networks and tiny machine learning techniques. The AID-Stick utilizes spectrogram, Mel-frequency cepstral coefficient, and Mel filterbank energy for real-time, on-microcontroller unit diagnostics of auditory signals from tile tapping tests. Our methodology effectively utilizes these acoustic features in distinguishing between intact and subsurface hollow defective tiles. The study’s findings, revealing a notable validation accuracy of 97% and a real-world accuracy of 81.25%, showcase a promising improvement over traditional methods. The AID-Stick’s practicality, cost-effectiveness, and user-friendly design make it potentially beneficial for small-to-medium enterprises and economically constrained markets. Furthermore, this research opens avenues for future enhancements in embedded AI systems, with potential applications extending beyond the construction industry to other domains requiring non-destructive testing. This work not only contributes to the field of industrial quality control but also to the development of intelligent diagnostic tools, paving the way for future innovations in automated inspection technologies.
A framework for improving UAV decision of autonomous navigation from training to application migration under perceptual uncertainty
Authors: Sheng Yuanyuan , Liu Huanyu , Li Junbao , Han Qi
Published: February 2024

Unmanned aerial vehicles (UAVs) autonomous navigation based on reinforcement learning usually requires training agents in simulation scenarios and then transferring the trained agents to application scenarios. However, due to serious distribution mismatch between the idealized simulation scenario and the application environment and the inevitable uncertainty perception problem of airborne sensors in complex scenarios, the navigation performance of UAV under migration applications is not ideal. This work fully analyzes the factors that affect UAV navigation performance, including algorithm performance, training strategy, and state awareness. Based on the analysis results, this article proposes a framework to improve the autonomous navigation performance of UAVs in the migration process from training to application, which consists of three parts: ‘scenario-perception-algorithm’. In addition, this paper proposes improvement strategies for each part from the perspectives of spatial features, temporal features, and perceptual denoising. We combine the proposed framework with navigation algorithms to improve the navigation decision-making performance of UAVs in migration applications under uncertainty perception. Many simulation experiments demonstrate the effectiveness of the proposed framework and its robustness to uncertainty perception.
Real-time visual SLAM based YOLO-Fastest for dynamic scenes
Authors: Gong Can , Sun Ying , Zou Chunlong , Tao Bo , Huang Li , Fang Zifan , Tang Dalai
Published: February 2024

Within the realm of autonomous robotic navigation, simultaneous localization and mapping (SLAM) serves as a critical perception technology, drawing heightened attention in contemporary research. The traditional SLAM systems perform well in static environments, but in the real physical world, dynamic objects can destroy the static geometric constraints of the SLAM system, further limiting its practical application in the real world. In this paper, a robust dynamic RGB-D SLAM system is proposed to expand the number of static points in the scene by combining with YOLO-Fastest to ensure the effectiveness of the geometric constraints model construction, and then based on that, a new thresholding model is designed to differentiate the dynamic features in the objection bounding box, which takes advantage of the double polyline constraints and the residuals after reprojection to filter the dynamic feature points. In addition, two Gaussian models are constructed to segment the moving objects in the bounding box in the depth image to achieve the effect similar to the instance segmentation under the premise of ensuring the computational speed. In this paper, experiments are conducted on dynamic sequences provided by the TUM dataset to evaluate the performance of the proposed method, and the results show that the root mean squared error metric of the absolute trajectory error of the algorithm of this paper has at least 80% improvement compared to ORB-SLAM2. Higher robustness in dynamic environments with both high and low dynamic sequences compared to DS-SLAM and Dynaslam, and can effectively provide intelligent localization and navigation for mobile robots.
Symmetry-selective quasiparticle scattering and electric field tunability of the ZrSiS surface electronic structure
Authors: Lodge Michael S , Marcellina Elizabeth , Zhu Ziming , Li Xiao-Ping , Kaczorowski Dariusz , Fuhrer Michael S , Yang Shengyuan A , Weber Bent
Published: February 2024

Three-dimensional Dirac semimetals with square-net non-symmorphic symmetry, such as ternary ZrXY (X = Si, Ge; Y = S, Se, Te) compounds, have attracted significant attention owing to the presence of topological nodal lines, loops, or networks in their bulk. Orbital symmetry plays a profound role in such materials as the different branches of the nodal dispersion can be distinguished by their distinct orbital symmetry eigenvalues. The presence of different eigenvalues suggests that scattering between states of different orbital symmetry may be strongly suppressed. Indeed, in ZrSiS, there has been no clear experimental evidence of quasiparticle scattering reported between states of different symmetry eigenvalues at small wave vector

q

⃗

.

Here we show, using quasiparticle interference, that atomic step-edges in the ZrSiS surface facilitate quasiparticle scattering between states of different symmetry eigenvalues. This symmetry eigenvalue mixing quasiparticle scattering is the first to be reported for ZrSiS and contrasts quasiparticle scattering with no mixing of symmetry eigenvalues, where the latter occurs with scatterers preserving the glide mirror symmetry of the crystal lattice, e.g. native point defects in ZrSiS. Finally, we show that the electronic structure of the ZrSiS surface, including its unique floating band surface state, can be tuned by a vertical electric field locally applied by the tip of a scanning tunneling microscope (STM), enabling control of a spin–orbit induced avoided crossing near the Fermi level by as much as 300%.
Tunable defect engineering of Mo/TiON electrode in angstrom-laminated HfO2/ZrO2 ferroelectric capacitors towards long endurance and high temperature retention
Authors: Wang Sheng-Min , Liu Cheng-Rui , Chen Yu-Ting , Lee Shao-Chen , Tang Ying-Tsan
Published: February 2024

A novel defect control approach based on laminated HfO2/ZrO2 with multifunctional TiN/Mo/TiO
x
N
y
electrode is proposed to significantly improve the endurance and data retention in HZO-based ferroelectric capacitor. The O-rich interface reduces leakage current and prolong the endurance up to 1011 cycles while retaining a 2Pr value of 34 (μC cm–2) at 3.4 MV cm−1. Using first-principles calculations and experiments, we demonstrate that the enhancement of endurance is ascribed to the higher migration barrier of oxygen vacancies within the laminated HZO film and higher work function of MoO
x
/TiO
x
N
y
between top electrode and the insulating oxide. This 2.5 nm thick TiO
x
N
y
barrier further increase the grain size of HZO, lowering the activation field and thus improving polarization reversal speed. This interfacial layer further decreases the overall capacitance, increases the depolarization field, thereby enhancing the data retention. By fitting the data using the Arrhenius equation, we demonstrate a 10 years data retention is achieved at 109.6 °C, surpassing traditional SS-HZO of 78.2 °C with a 450 °C rapid thermal annealing (required by backend-of-the-line). This work elucidates that interfacial engineering serves as a crucial technology capable of resolving the endurance, storage capability, and high-temperature data retention issues for ferroelectric memory.
Effectively coupling of SnSe2 nanosheet with N, Se co-doped carbon nanofibers as self-standing anode for lithium-ion batteries
Authors: Guo Xiangdong , Guo Kaixuan , Chen Song , Liang Junfei , Zhu Jian
Published: February 2024

Tin selenides possess layered structure and high theoretical capacity, which is considered as desirable anode material for lithium-ion batteries. However, its further development is limited by the low intrinsic electrical conductivity and sluggish reaction kinetics. Herein, a well-designed structure of SnSe2 nanosheet attached on N, Se co-doped carbon nanofibers (SnSe2@CNFs) is fabricated as self-standing anodes for lithium-ion batteries. The integration of structural engineering and heteroatom doping enables accelerated electrons transfer and rapid ion diffusion for boosting Li+ storage performance. Impressively, the flexible SnSe2@CNFs anodes exhibit inspiring capacity of 837.7 mAh g−1 after 800 cycles at 1.2 C with coulombic efficiency almost 100% and superior rate performance 419.5 mAh g−1 at 2.4 C. The kinetics analysis demonstrates the pseudocapacitive characteristic of SnSe2@CNFs promotes the storage property. This work sheds light on the hierarchical electrode construction towards high-performance energy storage applications.
A cathodoluminescence study of InP/InGaP axially heterostructured NWs for tandem solar cells
Authors: Mediavilla I , Anaya J , Galiana B , Hrachowina L , Borgström M T , Jimenez J
Published: February 2024

Axially heterostructured nanowires (NWs) constitute a promising platform for advanced electronic and optoelectronic nanodevices. The presence of different materials in these NWs introduces a mismatch resulting in complex strain distributions susceptible of changing the band gap and carrier mobility. The growth of these NWs presents challenges related to the reservoir effect in the catalysts droplet that affect to the junction abruptness, and the occurrence of undesired lateral growth creating core–shell heterostructures that introduce additional strain. We present herein a cathodoluminescence (CL) analysis on axially heterostructured InP/InGaP NWs with tandem solar cell structure. The CL is complemented with micro Raman, micro photoluminescence (PL), and high resolution transmission electron microscopy measurements. The results reveal the zinc blende structure of the NWs, the presence of a thin InGaP shell around the InP bottom cell, along with its associated strain, and the doping distribution.
High-performance MoS2 phototransistors with Hf1–x
Al
x
O back-gate dielectric layer grown by plasma enhanced atomic layer deposition
Authors: Yu Qiu-Jun , Li Xiao-Xi , Li Yu-Chun , Ding Si-Tong , Huang Teng , Gu Ze-Yu , Ou Lang-Xi , Lu Hong-Liang
Published: February 2024

Molybdenum sulfide (MoS2) as an emerging optoelectronic material, shows great potential for phototransistors owing to its atomic thickness, adjustable band gap, and low cost. However, the phototransistors based on MoS2 have been shown to have some issues such as large gate leakage current, and interfacial scattering, resulting in suboptimal optoelectronic performance. Thus, Al-doped hafnium oxide (Hf1–x
Al
x
) is proposed to be a dielectric layer of the MoS2-based phototransistor to solve this problem because of the relatively higher crystallization temperature and dielectric constant. Here, a high-performance MoS2 phototransistor with Hf1–x
Al
x
O gate dielectric layer grown by plasma-enhanced atomic layer deposition has been fabricated and studied. The results show that the phototransistor exhibits a high responsivity of 2.2 × 104 A W−1, a large detectivity of 1.7 × 1017 Jones, a great photo-to-dark current ratio of 2.2 × 106%, and a high external quantum efficiency of 4.4 × 106%. The energy band alignment and operating mechanism were further used to clarify the reason for the enhanced MoS2 phototransistor. The suggested MoS2 phototransistors could provide promising strategies in further optoelectronic applications.
Treatment planning for photodynamic therapy of abscess cavities using patient-specific optical properties measured prior to illumination
Authors: Li Zihao , Hannan Md Nafiz , Sharma Ashwani K , Baran Timothy M
Published: February 2024

Photodynamic therapy (PDT) is an effective antimicrobial therapy that we used to treat human abscess cavities in a Phase 1 clinical trial. This trial included pre-PDT measurements of abscess optical properties, which affect light dose (light fluence) at the abscess wall and PDT response. This study simulated PDT treatment planning for 13 subjects that received optical spectroscopy prior to clinical PDT, to determine the impact of measured optical properties on ability to achieve fluence rate targets in 95% of the abscess wall. Retrospective treatment plans were evaluated for 3 conditions: (1) clinically delivered laser power and assumed, homogeneous optical properties, (2) clinically delivered laser power and measured, homogeneous optical properties, and (3) with patient-specific treatment planning using measured, homogeneous optical properties. Treatment plans modified delivered laser power, intra-cavity Intralipid (scatterer) concentration, and laser fiber type. Using flat-cleaved laser fibers, the proportion of subjects achieving 95% abscess wall coverage decreased significantly relative to assumed optical properties when using measured values for 4 mW cm−2 (92% versus 38%, p = 0.01) and 20 mW cm−2 (62% versus 15%, p = 0.04) thresholds. When measured optical properties were incorporated into treatment planning, the 4 mW cm−2 target was achieved for all cases. After treatment planning, optimal Intralipid concentration across subjects was 0.14 ± 0.09%, whereas 1% was used clinically. Required laser power to achieve the 4 mW cm−2 target was significantly correlated with measured abscess wall absorption (ρ = 0.7, p = 0.008), but not abscess surface area (ρ = 0.2, p = 0.53). When using spherical diffuser fibers for illumination, both optimal Intralipid concentration (p = 0.0005) and required laser power (p = 0.0002) decreased compared to flat cleaved fibers. At 0% Intralipid concentration, the 4 mW cm−2 target could only be achieved for 69% of subjects for flat-cleaved fibers, compared to 100% for spherical diffusers. Based on large inter-subject variations in optical properties, individualized treatment planning is essential for abscess photodynamic therapy. (Clinical Trial Registration: The parent clinical trial from which these data were acquired is registered on ClinicalTrials.gov as ‘Safety and Feasibility Study of Methylene Blue Photodynamic Therapy to Sterilize Deep Tissue Abscess Cavities,’ with ClinicalTrials.gov identifier NCT02240498).
An adaptive h-refinement method for the boundary element fast multipole method for quasi-static electromagnetic modeling
Authors: Wartman William A , Weise Konstantin , Rachh Manas , Morales Leah , Deng Zhi-De , Nummenmaa Aapo , Makaroff Sergey N
Published: February 2024

Objective. In our recent work pertinent to modeling of brain stimulation and neurophysiological recordings, substantial modeling errors in the computed electric field and potential have sometimes been observed for standard multi-compartment head models. The goal of this study is to quantify those errors and, further, eliminate them through an adaptive mesh refinement (AMR) algorithm. The study concentrates on transcranial magnetic stimulation (TMS), transcranial electrical stimulation (TES), and electroencephalography (EEG) forward problems. Approach. We propose, describe, and systematically investigate an AMR method using the boundary element method with fast multipole acceleration (BEM-FMM) as the base numerical solver. The goal is to efficiently allocate additional unknowns to critical areas of the model, where they will best improve solution accuracy. The implemented AMR method’s accuracy improvement is measured on head models constructed from 16 Human Connectome Project subjects under problem classes of TES, TMS, and EEG. Errors are computed between three solutions: an initial non-adaptive solution, a solution found after applying AMR with a conservative refinement rate, and a ‘silver-standard’ solution found by subsequent 4:1 global refinement of the adaptively-refined model. Main results. Excellent agreement is shown between the adaptively-refined and silver-standard solutions for standard head models. AMR is found to be vital for accurate modeling of TES and EEG forward problems for standard models: an increase of less than 25% (on average) in number of mesh elements for these problems, efficiently allocated by AMR, exposes electric field/potential errors exceeding 60% (on average) in the solution for the unrefined models. Significance. This error has especially important implications for TES dosing prediction—where the stimulation strength plays a central role—and for EEG lead fields. Though the specific form of the AMR method described here is implemented for the BEM-FMM, we expect that AMR is applicable and even required for accurate electromagnetic simulations by other numerical modeling packages as well.
SST: a snore shifted-window transformer method for potential obstructive sleep apnea patient diagnosis
Authors: Luo Jing , Zhao Yinuo , Liu Haiqin , Zhang Yitong , Shi Zhenghao , Li Rui , Hei Xinhong , Ren Xiaorong
Published: February 2024

Objective. Obstructive sleep apnea (OSA) is a high-incidence disease that is seriously harmful and potentially dangerous. The objective of this study was to develop a noncontact sleep audio signal-based method for diagnosing potential OSA patients, aiming to provide a more convenient diagnostic approach compared to the traditional polysomnography (PSG) testing. Approach. The study employed a shifted window transformer model to detect snoring audio signals from whole-night sleep audio. First, a snoring detection model was trained on large-scale audio datasets. Subsequently, the deep feature statistical metrics of the detected snore audio were used to train a random forest classifier for OSA patient diagnosis. Main results. Using a self-collected dataset of 305 potential OSA patients, the proposed snore shifted-window transformer method (SST) achieved an accuracy of 85.9%, a sensitivity of 85.3%, and a precision of 85.6% in OSA patient classification. These values surpassed the state-of-the-art method by 9.7%, 10.7%, and 7.9%, respectively. Significance. The experimental results demonstrated that SST significantly improved the noncontact audio-based OSA diagnosis performance. The study’s findings suggest a promising self-diagnosis method for potential OSA patients, potentially reducing the need for invasive and inconvenient diagnostic procedures.
Molecular nanomagnets: a viable path toward quantum information processing?
Authors: Chiesa A , Santini P , Garlatti E , Luis F , Carretta S
Published: February 2024

Molecular nanomagnets (MNMs), molecules containing interacting spins, have been a playground for quantum mechanics. They are characterized by many accessible low-energy levels that can be exploited to store and process quantum information. This naturally opens the possibility of using them as qudits, thus enlarging the tools of quantum logic with respect to qubit-based architectures. These additional degrees of freedom recently prompted the proposal for encoding qubits with embedded quantum error correction (QEC) in single molecules. QEC is the holy grail of quantum computing and this qudit approach could circumvent the large overhead of physical qubits typical of standard multi-qubit codes. Another important strength of the molecular approach is the extremely high degree of control achieved in preparing complex supramolecular structures where individual qudits are linked preserving their individual properties and coherence. This is particularly relevant for building quantum simulators, controllable systems able to mimic the dynamics of other quantum objects. The use of MNMs for quantum information processing is a rapidly evolving field which still requires to be fully experimentally explored. The key issues to be settled are related to scaling up the number of qudits/qubits and their individual addressing. Several promising possibilities are being intensively explored, ranging from the use of single-molecule transistors or superconducting devices to optical readout techniques. Moreover, new tools from chemistry could be also at hand, like the chiral-induced spin selectivity. In this paper, we will review the present status of this interdisciplinary research field, discuss the open challenges and envisioned solution paths which could finally unleash the very large potential of molecular spins for quantum technologies.
Interaction graph engineering in trapped-ion quantum simulators with global drives
Authors: Kyprianidis Antonis , Rasmusson A J , Richerme Philip
Published: February 2024

Trapped-ion quantum simulators have demonstrated a long history of studying the physics of interacting spin-lattice systems using globally addressed entangling operations. Yet despite the multitude of studies so far, most have been limited to studying variants of the same spin interaction model, namely an Ising model with power-law decay in the couplings. Here, we demonstrate that much broader classes of effective spin–spin interactions are achievable using exclusively global driving fields. Specifically, we find that these new categories of interaction graphs become achievable with perfect or near-perfect theoretical fidelity by tailoring the coupling of the driving fields to each vibrational mode of the ion crystal. Given the relation between the ion crystal vibrational modes and the accessible interaction graphs, we show how the accessible interaction graph set can be further expanded by shaping the trapping potential to include specific anharmonic terms. Finally, we derive a rigorous test to determine whether a desired interaction graph is accessible using only globally driven fields. These tools broaden the reach of trapped-ion quantum simulators so that they may more easily address open questions in materials science and quantum chemistry.
Quantifying the unextendibility of entanglement*
Authors: Wang Kun , Wang Xin , Wilde Mark M
Published: February 2024

Entanglement is a striking feature of quantum mechanics, and it has a key property called unextendibility. In this paper, we present a framework for quantifying and investigating the unextendibility of general bipartite quantum states. First, we define the unextendible entanglement, a family of entanglement measures based on the concept of a state-dependent set of free states. The intuition behind these measures is that the more entangled a bipartite state is, the less entangled each of its individual systems is with a third party. Second, we demonstrate that the unextendible entanglement is an entanglement monotone under two-extendible quantum operations, including local operations and one-way classical communication as a special case. Normalization and faithfulness are two other desirable properties of unextendible entanglement, which we establish here. We further show that the unextendible entanglement provides efficiently computable benchmarks for the rate of exact entanglement or secret key distillation, as well as the overhead of probabilistic entanglement or secret key distillation.
PT-symmetry rules applied to a class of real potentials
Authors: Garidi S , Lombard R J , Mezhoud R
Published: February 2024

Extending the functional space to complex eigenfunctions R J Lombard et al (2022, Rom. J. Phys.
67, 104), we have shown that infinitely negative potentials at large distances admit finite energy states. The used techniques are similar to the ones applied in the case of PT symmetric complex potentials with real eigenvalues. We present the lowest part of the spectra for −∣x∣
n
potentials with 4 ≤ n ≤ 8. We also discuss the norm and orthogonality of the wave functions.
Numerical and experimental study on pole teeth interlaced divergent ferrofluid seals with single magnetic source
Authors: Li Denghui , Huang Yinyan , Lei Yang , Yang Xiaolong
Published: February 2024

For the improvement of pressure resistance in ferrofluid seal with a small gap, a structure of divergent ferrofluid seal (FS) with alternating pole teeth (PT) was proposed in this paper. Distribution of the magnetic field in the seal gap (SG) is analyzed by using the magnetic field finite element method, and the theoretical pressure resistance (PR) is calculated by using the step ferrofluid seal PR theory. Effect of the number of pole teeth and seal gap on its sealing PR were studied experimentally. The PR of the interlaced divergent FS is compared to the experimental findings of a conventional ferrofluid seal structure. The results show that the actual pressure value of the interlaced divergent FS is consistent with its theoretical pressure value well. Compared to the common ferrofluid seal, the interlaced divergent FS has better PR.
Experimental investigation of near-field magnetic energy harvesting from induction cooktop
Authors: Kumar Ajit , Yadav Subash Chandra , V. Sivavenkateswara Rao , Duttagupta SP
Published: February 2024

This paper proposes a simple and cost-effective magnetic-field-energy harvesting circuit for capturing the leaked magnetic energy from an induction cooktop. In this, the captured energy is converted into dc electrical energy with the help of 1N5819 Schottky diodes based full wave bridge rectifier. We investigated the captured magnetic-field energy at different positions and different heights of the energy-harvesting coil from the induction cooktop. The designed Magnetic-Field-Energy Harvesting (MFEH) circuit is capable of capturing an average dc power of 1484 mW while it is placed 5 cm below the induction cooktop with a load resister 33 Ω and capacitance of 470 μF. The power level is reduced to 203 mW when the energy harvesting coil is moved to 10 cm below the induction cooktop. The harvested magnetic field energy at different positions of the energy harvesting coils is investigated for different values of load resisters. The harvested energy can be stored in a battery for future applications. The proposed device demonstrated practically for charging mobile and powering the low-power IoT device. The numerical study of the proposed harvesting mechanism is explained also. The induction cooktop’s yielded excellent results and magnetic field energy harvesting capability make the proposed device unique from the previously reported magnetic harvesting circuits.