bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of wall microstructure on conical hypersonic boundary layer flow
Authors: Zhang Zhen , Yi Shihe , Liu Xiaolin , Hu Yufa
Published: October 2024

As an effective boundary layer flow control method, wall microstructure has an important application prospect in heat and drag reduction of hypersonic. In this paper, based on experimental techniques such as high-frequency pressure fluctuation testing, the effects of different microstructure configurations (V-shaped and rectangular) and distribution modes (streamwise and transverse) on the flow of hypersonic conic boundary layer under the condition of Mach 6 hypersonic incoming flow are studied. The experimental results show that compared with the flow of the smooth wall boundary layer, the wall microstructure has a greater influence on the eigenfrequency of the second-mode wave in the boundary layer, and the streamwise increases by about 20 kHz to the rectangular microstructure and decreases by about 30 kHz to the transverse rectangular microstructure. At the same time, the transverse V-shaped microstructure can increase the amplitude of the second mode in the boundary layer by 5.5 times compared with the smooth wall. For the evolution of boundary layer flow, the microstructure arranged along the flow direction will accelerate the linear development of the disturbance wave during the transition, so that the laminar flow will be transformed into turbulent flow in a shorter distance. The microstructure arranged along the transverse direction prolongs the linear development stage of the disturbance wave during the transition, so that the laminar flow turns into turbulent flow over a longer distance. Downstream of different structures, it is shown that transverse rectangular microstructure has lowest temperatures.
Differential impacts of fire and inundation on a wetland plant community after wildfire
Authors: Mackay K. D. , Vincent B. , Southwell M. , Growns I. , Mika S.
Published: October 2024

Context Understanding fire and inundation impacts on wetland vegetation communities is crucial for effective post-fire wetland management. Aims We aimed to determine the impact of post-fire inundation on plant community structure and seedling germination and establishment after a large wildfire. We asked two questions, namely (1) did fire, drought or inundation affect plant communities the most; and (2) did fire or inundation affect seedling germination and establishment? Methods Using a before–after–control–impact (BACI) design, we monitored vegetation changes in water-couch wetland communities before and after a wildfire. Also, soil samples were collected from burnt and unburnt sites and assessed for impacts of fire and post-fire inundation regimes on seed germination and seedling establishment. Key results Inundation variables had more pronounced and more consistent impacts on vegetation measures than did fire or drought variables. Fire impacts were mainly short-term, with impact thresholds at 72 and 143 days after fire. Low germination levels and zero seedling survival were observed without inundation. Conclusions Fire was a major but short-term contributor to wetland vegetation change, whereas drought had longer-term impacts, and inundation regimes had the greatest impacts. Implications Providing a range of inundation conditions post-fire may enhance wetland vegetation recovery and have modifying effects on invasive species.
Species delimitations in the Campomanesia xanthocarpa group (Myrtaceae): insights from molecular markers and taxonomy
Authors: Oliveira Marla Ibrahim Uehbe de , Vieira João Paulo Silva , van den Berg Cássio , Funch Ligia Silveira , Oliveira Reyjane Patrícia de
Published: October 2024

Different views on recognising taxa associated with the Campomanesia xanthocarpa group (Myrtaceae) demonstrate the difficulties in clearly delimiting species. Studies using Inter Simple Sequence Repeats (ISSR) molecular markers were carried out on 201 individuals from 13 populations of C. xanthocarpa Mart. ex O.Berg, C. adamantium (Cambess.) O.Berg, C. costata M.Ibrahim & Landrum and C. littoralis D.Legrand in an attempt to improve understanding of species boundaries between these species. SplitsTree, analysis of molecular variance (AMOVA), principal component analysis (PCA), Neighbour-Joining (NJ) dendrogram and STRUCTURE showed inconsistencies between morphological and genetic data in these taxa. Therefore C. adamantium and C. xanthocarpa are treated as distinct taxa in this study, as are C. costata, C. littoralis and C. rhombea O.Berg that were previously considered part of C. xanthocarpa. Structured populations in C. adamantium were not congruent with taxonomic data or poorly supported in the data analysed. These were maintained as a single polymorphic species and new integrative approaches are necessary to improve understanding of taxon boundaries. We present a taxonomic treatment based on these decisions. This study contributes to the systematic treatment of Campomanesia and encourages specific delimitation studies to resolve remaining taxonomic issues within the genus.
Dynamics of standing dead wood and severe fire in north Australian savannas: implications for carbon management
Authors: Whitehead Peter J. , Murphy Brett P. , Evans Jay , Lynch Dominique , Yates Cameron P. , Edwards Andrew , Mcdermott Harry , Russell-Smith Jeremy
Published: October 2024

Background Many fires in north Australian savannas are severe enough to cause canopy scorch, tree death and removal of stags. Better fire management may increase carbon sequestration in trees, perhaps including stags. Aims To describe and analyse dynamics of stags in tropical savannas (600–1000 mm annual rainfall) in relation to fire and better understand their role in biomass sequestration. Methods We monitored marked populations of live and dead trees over 12 years. Statistical models describing influences on stag creation and loss are applied in stag dynamics simulations. Key results Immediately following severe fire, stag biomass increases acutely because many more live trees are killed than stags removed. Between severe fires, stag losses exceed tree deaths, so peaks are quite short. Many ‘new’ stags are lost (fallen or consumed) quickly. Conclusions Between fires, stags comprise ~7.5–8.9% of standing above-ground biomass, more under dry conditions and during recovery from severe fire or other drivers of increased tree mortality. Fire management is unlikely to increase proportions of total woody biomass in stags unless it also reduces live biomass. Implications Reducing frequency of severe fires can increase total carbon sequestration in dry tropical savannas. Prediction uncertainties and management risks around sequestration present daunting challenges for policy-makers and fire management practitioners.
BLNK negatively regulates innate antifungal immunity through inhibiting c-Cbl-mediated macrophage migration
Authors: Yang Yi-Heng , Xie Ke-Fang , Yang Shuai , Wang Huan , Ma Hui-Hui , Zhou Min , Wang Zhong-Wei , Gu Yebo , Jia Xin-Ming
Published: October 2024

B cell linker protein (BLNK) is crucial for orchestrating B cell receptor-associated spleen tyrosine kinase (Syk) signaling. However, the role of BLNK in Syk-coupled C-type lectin receptor (CLR) signaling in macrophages remains unclear. Here, we delineate that CLRs govern the Syk-mediated activation of BLNK, thereby impeding macrophage migration by disrupting podosome ring formation upon stimulation with fungal β-glucans or α-mannans. Mechanistically, BLNK instigates its association with casitas B-lineage lymphoma (c-Cbl), competitively impeding the interaction between c-Cbl and Src-family kinase Fyn. This interference disrupts Fyn-mediated phosphorylation of c-Cbl and subsequent c-Cbl-associated F-actin assembly. Consequently, BLNK deficiency intensifies CLR-mediated recruitment of the c-Cbl/phosphatidylinositol 3-kinase complex to the F-actin cytoskeleton, thereby enhancing macrophage migration. Notably, mice with monocyte-specific BLNK deficiency exhibit heightened resistance to infection with
Candida albicans
, a prominent human fungal pathogen. This resistance is attributed to the increased infiltration of Ly6C
+
macrophages into renal tissue. These findings unveil a previously unrecognized role of BLNK for the negative regulation of macrophage migration through inhibiting CLR-mediated podosome ring formation during fungal infections.
Gut-to-brain regulation of
Drosophila
aging through neuropeptide F, insulin, and juvenile hormone
Authors: Chen Jiangtian , Nouzová Marcela , Noriega Fernando G. , Tatar Marc
Published: October 2024

Dietary restriction (DR) slows aging in many animals, while in some cases, the sensory signals from diet alone are sufficient to retard or accelerate lifespan. The digestive tract is a candidate location to sense nutrients, where neuropeptides secreted by enteroendocrine cells (EEC) produce systemic signals in response to food. Here, we measure how
Drosophila
neuropeptide F (NPF) is secreted into adult circulation by EEC and find that specific EEC differentially respond to dietary sugar and yeast. Female lifespan is increased when gut NPF is genetically depleted, and this manipulation is sufficient to blunt the longevity benefit conferred by DR. Depletion of NPF receptors at insulin-producing neurons of the brain also increases female lifespan, consistent with observations where loss of gut NPF decreases neuronal insulin secretion. The longevity conferred by repressing gut NPF and brain NPF receptors is reversed by treating adults with a juvenile hormone (JH) analog. JH is produced by the adult corpora allata, and inhibition of the insulin receptor at this tissue decreases JH titer and extends lifespan in both males and females, while this longevity is restored to wild type by treating adults with a JH analog. Overall, EEC of the gut modulate
Drosophila
aging through interorgan communication mediated by a gut–brain–corpora allata axis, and insulin produced in the brain impacts lifespan through its control of JH titer. These data suggest that we consider how human incretins and their analogs, which are used to treat obesity and diabetes, may impact aging.
Spherical accretion onto higher-dimensional Reissner–Nordström black hole
Authors: Das Bibhash , Chanda Anirban , Paul Bikash Chandra
Published: October 2024

We obtain relativistic solutions of spherically symmetric accretion by a dynamical analysis of a generalised Hamiltonian for higher-dimensional Reissner–Nordström (RN) Black Hole (BH). We consider two different fluids namely, an isotropic fluid and a non-linear polytropic fluid to analyse the critical points in a higher-dimensional RN BH. The flow dynamics of the fluids are studied in different spacetime dimensions in the framework of Hamiltonian formalism. The isotropic fluid is found to have both transonic and non-transonic flow behaviour, but in the case of polytropic fluid, the flow behaviour is found to exhibit only non-transonic flow, determined by a critical point that is related to the local sound speed. The critical radius is found to change with the spacetime dimensions. Starting from the usual four dimensions it is noted that as the dimension increases the critical radius decreases, attains a minimum at a specific dimension (D > 4) and thereafter increases again. The mass accretion rate for isotropic fluid is determined using Hamiltonian formalism. The maximum mass accretion rate for RN BH with different equations of state parameters is studied in addition to spacetime dimensions. The flow behaviour and mass accretion rate for a change in BH charge is also studied analytically. It is noted that the maximum mass accretion rate in a higher-dimensional Schwarzschild BH is the lowest, which however, increases with the increase in charge parameter in a higher-dimensional RN BH.
Distinguishing the XUV-induced Coulomb explosion dynamics of iodobenzene using covariance analysis
Authors: Walmsley Tiffany , Allum Felix , Harries James R , Kumagai Yoshiaki , Lim Suzanne , McManus Joseph , Nagaya Kiyonobu , Britton Mathew , Brouard Mark , Bucksbaum Philip , Fushitani Mizuho , Gabalski Ian , Gejo Tatsuo , Hockett Paul , Howard Andrew J , Iwayama Hiroshi , Kukk Edwin , Lam Chow-shing , Minns Russell S , Niozu Akinobu , Nishimuro Sekito , Niskanen Johannes , Owada Shigeki , Razmus Weronika O , Rolles Daniel , Somper James , Ueda Kiyoshi , Unwin James , Wada Shin-ichi , Woodhouse Joanne L , Forbes Ruaridh , Burt Michael , Warne Emily M
Published: October 2024

The primary and secondary fragmentation dynamics of iodobenzene following its ionization at 120 eV were determined using three-dimensional velocity map imaging and covariance analysis. Site-selective iodine 4d ionization was used to populate a range of excited polycationic parent states, which primarily broke apart at the carbon-iodine bond to produce I+ with phenyl or phenyl-like cations (C
n
H

x

+

or C
n
H

x

2
+

, with n  =  1 – 6 and x  =  1 – 5). The molecular products were produced with varying degrees of internal excitation and dehydrogenation, leading to stable and unstable outcomes. This further allowed the secondary dynamics of

C

6

H

x

2
+

intermediates to be distinguished using native-frame covariance analysis, which isolated these processes in their own centre-of-mass reference frames. The mass resolution of the imaging mass spectrometer used for these measurements enabled the primary and secondary reaction channels to be specified at the level of individual hydrogen atoms, demonstrating the ability of covariance analysis to comprehensively measure the competing fragmentation channels of aryl cations, including those involving intermediate steps.
A novel simulation of space charge decay dynamics after removing the voltage in epoxy resin composites
Authors: Zhang Hongliang , Jin Shiyu , Jin Hai , Zhang Ziyu , Wang Chuang , Liu Peng
Published: October 2024

Epoxy resin serves as a critical insulating component in ultra-high voltage dry direct current bushings. However, the accumulation of space charges within the epoxy resin, a byproduct of charge mobility, poses a significant risk to the reliability and operational safety of bushings. Conventional space charge attenuation models, especially after voltage removal, have limited use in simulations aimed at understanding this phenomenon. This study introduces an improved model integrating the bipolar charge transport mechanism with space charge decay based on the hopping conduction mechanism and Schottky’s theorem, establishes a theoretical framework for predicting the space charge behavior following voltage removal, and conducts a simulation to investigate the decay process within the internal structure of epoxy resin and measure the residual charges after voltage removal using the pulsed electro-acoustic method. The experimental data validate the accuracy of the proposed model and theoretical assumptions. The findings show that the remaining negative charges after voltage removal are not enhanced by the field enhancement; the anodic positive and cathodic positive charges are distributed in two-segment discontinuous traps, whereas the negative charges are distributed in one-segment traps. The model identifies two distinct trapping sites for anodic and cathodic positive charges, and one trapping site for negative charges. After voltage removal, when the field strength exceeded 40 kV mm−1, positive charges exist near the upper and lower electrodes, and negative charges exist near the center of the specimen. The consistency between the simulated predictions and experimental data proves the effectiveness of the proposed model in accurately simulating the space charge decay in epoxy materials after voltage removal.
Plasma activated solution synergistic with exogenous RONS enhances cancer cell apoptosis for improved tumor therapy
Authors: Liu Zhijie , Tantai Xiamin , Zhang Zekai , Li Xin , Pang Bolun , Wang Yuheng
Published: October 2024

The role of reactive oxygen and nitrogen species (RONS) in plasma-activated solution (PAS) for inducing cancer cell apoptosis is well-established, but suboptimal concentrations and rapid degradation often limit their efficacy. This study addresses a significant gap in current research by exploring how the incorporation of exogenous RONS into PAS can enhance apoptosis in cancer cells, potentially overcoming the limitations of traditional PAS treatments. In this study, the effect of treating saline with a plasma jet for different durations was investigated to analyze how its chemical composition triggers apoptosis in cancer cells in vitro. It was observed that longer plasma treatment times resulted in lower cell viability, the reactive species of H2O2, NO2
− and ONOO− were found to play a crucial role in inducing apoptosis in cancer cells. Based on these findings, the anticancer efficacy of PAS was further evaluated after the addition of specific exogenous RONS, using measures such as cell viability, intracellular ROS levels, and microscopic imaging. Biological experiments demonstrated that the anticancer efficacy followed the order: addition of RONS to saline before plasma discharge treatment > addition of RONS to saline after plasma discharge treatment > exogenous RONS solution without plasma treatment. This suggests that the external introduction of RONS can modify the chemical composition of PAS to effectively enhance its anticancer properties, with the addition of H2O2 before plasma discharge treatment proving to be the most effective strategy. These results provide a novel perspective on harnessing the anticancer potential of PAS and expanding its potential applications in tumor therapy.
An adaptive assisted method based on MOPSO for THz MMA effective designing
Authors: Qu Weiwei , Wang Yurong , Li Guilin , Xie Zhaohui , Li Zongren , Deng Hu , Shang Liping
Published: October 2024

To address the high time cost and low efficiency of traditional terahertz (THz) metamaterial absorber (MMA) design, an adaptive method based on multi-objective particle swarm optimization (PSO) was proposed. First, we presented a symmetric absorber of a four-split-ring resonator with a cross-shaped top layer. The structural parameters were optimized by the PSO and multi-objective PSO (MOPSO) algorithms. The simulation results indicated that the MOPSO rapidly obtained geometric parameters that balance the high absorptivity and high quality factors. This method quickly identified a symmetric structure with absorptivity greater than 99% and quality factor of 377.45 at 1.584 THz. Additionally, the asymmetric structure achieved near-perfect absorption at 1.585 THz with a Q value of 281.32. By studying the electric field distribution and the surface current distribution, the physical mechanism of the absorber designed has been explained. This adaptive assisted method based on MOPSO can efficiently design MMAs and offer an artificial intelligence strategy for THz functional device design.
High-performance supercapacitor of ZnO-incorporated structurally modified g-C3N4 with circular mesoporous channels attained via a template-free approach
Authors: T Jasna , Subrahmanian Suvarna K , V P Kavya , A P Haritha , T T Karthika , M Shemeena , P Jabira , Narayanan Binitha N
Published: October 2024

Here, the superior structural features of graphitic carbon nitride (g-C3N4) in combination with integrated mesoporous channels have been explored for its use as a supercapacitor electrode material. A facile template-free strategy is adopted for the preparation of ZnO-incorporated modified g-C3N4 nanocomposite, where material characterization via x-ray difraction, Fourier transfrom infrared spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy and x-ray photoelectron spectroscopy analysis revealed the presence of structurally modified g-C3N4 having uniform circular mesoporous channels with well-dispersed ZnO with strong Zn–C and Zn–N interactions. The electrical double-layer capacitance together with the pseudocapacitance of the ZnO/g-C3N4 electrode material resulted in improved performance, leading to a specific capacitance of 146.3 F g−1 at a current density of 0.5 A g−1; an increased capacitance is observed in 5000 repeated charge–discharge cycles. A symmetric coin cell supercapacitor fabricated from the material displayed an energy density of 38.8 mWh kg−1 at a power density of 4259 mW kg−1. Additionally, the long life of 6000 cycles (retaining 100% specific capacitance) exhibited by the coin cell supercapacitor further indicates the promising energy storage nature of the ZnO-incorporated modified g-C3N4 mesoporous nanoarchitecture. Real life application of the ZnO/g-C3N4-derived supercapacitor is illustrated by lighting up a green LED with a series connection of four coin cells.
Demonstration of aluminum nitride metal oxide semiconductor field effect transistor on sapphire substrate
Authors: Chettri Dhanu , Mainali Ganesh , Cao Haicheng , Salcedo Juan Huerta , Nong Mingtao , Kumar Mritunjay , Yuvaraja Saravanan , Tang Xiao , Liao CheHao , Li Xiaohang
Published: October 2024

Aluminum nitride (AlN) is a promising ultrawide bandgap material with significant advantages for power electronics and optoelectronic applications due to its high breakdown voltage, mobility, and thermal conductivity. AlN Schottky barrier diodes and metal semiconductor field effect transistors have shown potential but are limited by issues such as high off-state leakage current and complex structures to achieve ohmic contacts. To address these challenges, we report on the fabrication and characterization of an AlN metal oxide semiconductor field effect transistor (MOSFET) with a recessed gate structure. The source and drain contacts were fabricated on n-doped AlN epitaxy using Ti-based contacts with a Ti/Al/Ti/Au metal stack. To evaluate the performance of these contacts, a circular transmission line model was employed, and contacts were annealed at various temperatures ranging from 750 °C to 950 °C in a nitrogen ambient. Our results reveal that unannealed Ti-based contacts on AlN showed no current conduction. However, annealing these contacts at 950 °C for 30 s significantly reduced the specific contact resistance to 0.148 Ω·cm2, achieving an ∼80% reduction compared to samples annealed at 750 °C. Utilizing these optimized contact conditions, we fabricated, to the best of our knowledge, the first AlN MOSFET. The fabricated AlN MOSFET exhibits a threshold voltage of −10.91 V, an effective mobility of 2.95 cm2 V−1 s−1, an on–off current ratio spanning two orders of magnitude, and a reverse breakdown voltage of approximately ∼250 V in air without a field plate.
Superconducting resonator parametric amplifiers with intrinsic separation of pump and signal tones
Authors: Zhao Songyuan , Withington S , Thomas C N
Published: October 2024

Superconducting resonator parametric amplifiers achieve ultra-low-noise amplification through the nonlinear kinetic inductance of thin-film superconductors. One of the main challenges to the operation of these devices is the separation of the strong pump tone from the signal tone after amplification has been achieved. In this paper, we propose and experimentally demonstrate a pump separation method based on operating a half-wave superconducting resonator amplifier behind a cryogenic circulator. Our pump separation scheme does not involve post-amplification interference, and thereby avoids the delicate phase matching of two different pump paths. We demonstrate the scheme using two-port half-wave resonator amplifiers based on superconducting NbN thin-films. We present measurements of gain profiles and degrees of pump separation for amplifiers having different coupling quality factors. On an amplifier having a coupling quality factor of ∼2000, we measured a peak signal gain of

15

dB

whilst achieving pump separation of

12

dB

. The amplifier was stable for continuous measurements, and the gain drift was measured to be

0.15

dB

over an hour. The same amplifier was operated at

3.2

K

and achieved a peak signal gain of

11

dB

whilst having a pump separation factor of

10.5

dB

. The pump separation scheme, and these promising results, will advance the development of superconducting resonator amplifiers as an important technology in quantum sensing.
Spatio-temporal reconstruction of droplet impingement dynamics by means of color-coded glare points and deep learning
Authors: Dreisbach Maximilian , Kriegseis Jochen , Stroh Alexander
Published: October 2024

The present work introduces a deep learning approach for the three-dimensional reconstruction of the spatio-temporal dynamics of the gas–liquid interface on the basis of monocular images obtained via optical measurement techniques. The method is tested and evaluated at the example of liquid droplets impacting on structured solid substrates. The droplet dynamics are captured through high-speed imaging in an extended shadowgraphy setup with additional glare points from lateral light sources that encode further three-dimensional information of the gas–liquid interface in the images. A neural network is trained for the physically correct reconstruction of the droplet dynamics on a labeled dataset generated by synthetic image rendering on the basis of gas–liquid interface shapes obtained from direct numerical simulation. The employment of synthetic image rendering allows for the efficient generation of training data and circumvents the introduction of errors resulting from the inherent discrepancy of the droplet shapes between experiment and simulation. The accurate reconstruction of the three-dimensional shape of the gas–liquid interface during droplet impingement on the basis of images obtained in the experiment demonstrates the practicality of the presented approach based on neural networks and synthetic training data generation. The introduction of glare points from lateral light sources in the experiments is shown to improve the reconstruction accuracy, which indicates that the neural network learns to leverage the additional three-dimensional information encoded in the images for a more accurate depth estimation. By the successful reconstruction of obscured areas in the input images, it is demonstrated that the neural network has the capability to learn a physically correct interpolation of missing data from the numerical simulation. Furthermore, the physically reasonable reconstruction of unknown gas–liquid interface shapes for drop impact regimes that were not contained in the training dataset indicates that the neural network learned a versatile model of the involved two-phase flow phenomena during droplet impingement.
Local maximum synchrosqueezing adaptive transformation for cross-instantaneous frequencies analysis
Authors: Hou Yating , Zhang Junzhu , Han Xingcheng , Wang Liming , Xu Xudong , Zhang Shuai
Published: October 2024

To overcome the shortcomings of existing time-frequency (TF) analysis (TFA) methods in analyzing signals containing cross-instantaneous frequencies (IFs), this paper proposes an adaptive TFA technique combined with image processing methods based on local maximum synchrosqueezing transform (SST). The core idea of the proposed algorithm is to localize the filtering of signals containing several different IF components using kernel functions containing several different directions, respectively, to achieve energy separation at the crossing frequencies. In turn, the local maximum SST is used to rearrange the TF energy to the true IF ridges of the signal to improve the TF energy concentration. Simulation data demonstrates that the proposed algorithm has higher energy aggregation and better noise immunity, especially for signals with cross-IFs. Applying the proposed method to animal acoustic and radar wave signals of pedestrians can accurately describe the differences in the frequency change patterns and the temporal distribution of energy in the signals, thereby providing a judgment basis for effectively identifying and classifying the signals.
From materials to structures: a holistic examination of achieving linearity in flexible pressure sensors
Authors: Li Pei , Zhang Yong , Li Chunbao , Chen Xian , Gou Xin , Zhou Yong , Yang Jun , Xie Lei
Published: October 2024

As a pivotal category in the realm of electronics skins, flexible pressure sensors have become a focal point due to their diverse applications such as robotics, aerospace industries, and wearable devices. With the growing demands for measurement accuracy, data reliability, and electrical system compatibility, enhancing sensor’s linearity has become increasingly critical. Analysis shows that the nonlinearity of flexible sensors primarily originates from mechanical nonlinearity due to the nolinear deformation of polymers and electrical nonlinearity caused by changes in parameters such as resistance. These nonlinearities can be mitigated through geometric design, material design or combination of both. This work reviews linear design strategies for sensors from the perspectives of structure and materials, covering the following main points: (a) an overview of the fundamental working mechanisms for various sensors; (b) a comprehensive explanation of different linear design strategies and the underlying reasons; (c) a detailed review of existing work employing these strategies and the achieved effects. Additionally, this work delves into diverse applications of linear flexible pressure sensors, spanning robotics, safety, electronic skin, and health monitoring. Finally, existing constraints and future research prospects are outlined to pave the way for the further development of high-performance flexible pressure sensors.
Synergistic applications of quantum dots and magnetic nanomaterials in pathogen detection: a comprehensive review
Authors: Shalileh Farzaneh , Shamani Negin , Golbashy Mohammad , Dadmehr Mehdi , Hosseini Morteza
Published: October 2024

The rapid and accurate detection of pathogens is crucial for effective disease prevention and management in healthcare, food safety, and environmental monitoring. While conventional pathogen detection methods like culture-based techniques and PCR are sensitive and selective, they are often time-consuming, require skilled operators, and are not suitable for point-of-care or on-site testing. To address these limitations, innovative sensor technologies have emerged that leverage the unique properties of nanomaterials. Quantum dots (QDs) and magnetic nanomaterials are two classes of nanomaterials that have shown particular promise for pathogen sensing. This review comprehensively examines the synergistic applications of QDs and magnetic nanomaterials for detecting bacteria, viruses, phages, and parasites.
Flocking analysis and control of a nonlinear collective migration model
Authors: Chen Yipeng , Liu Yicheng , Wang Xiao
Published: October 2024

In this paper, we study a nonlinear collective migration model with the Cucker–Smale type weight, the nonlinear velocity coupling and the distributed network. Finite-time flocking tracking can be achieved by the alignment force gathering agents and the tracking force matching target. A trade-off existing between the two forces is established by the tracking strategy that can be viewed as a control. When the strategy is time-invariant, finite-time flocking tracking would occur for any initial state under the long-range weight, only for partial initial state under the short-range weight. An invariant set of the system is proposed and proved to be an attractive domain of the flocking state. Then two time-varying strategies, the average strategy and the maximum strategy, are designed to overcome the constraint of initial state under the short-range weight. The average strategy has to mobilize all agents simultaneously, but only causes once switch. The maximum strategy only mobilizes the agent with the largest velocity deviation, but produces more switches. Several numerical simulations are provided to observe the effects of the time-invariant and time-varying strategies.
Deep learning-based automatic contour quality assurance for auto-segmented abdominal MR-Linac contours
Authors: Zarenia Mohammad , Zhang Ying , Sarosiek Christina , Conlin Renae , Amjad Asma , Paulson Eric
Published: October 2024

Objective. Deep-learning auto-segmentation (DLAS) aims to streamline contouring in clinical settings. Nevertheless, achieving clinical acceptance of DLAS remains a hurdle in abdominal MRI, hindering the implementation of efficient clinical workflows for MR-guided online adaptive radiotherapy (MRgOART). Integrating automated contour quality assurance (ACQA) with automatic contour correction (ACC) techniques could optimize the performance of ACC by concentrating on inaccurate contours. Furthermore, ACQA can facilitate the contour selection process from various DLAS tools and/or deformable contour propagation from a prior treatment session. Here, we present the performance of novel DL-based 3D ACQA models for evaluating DLAS contours acquired during MRgOART. Approach. The ACQA model, based on a 3D convolutional neural network (CNN), was trained using pancreas and duodenum contours obtained from a research DLAS tool on abdominal MRIs acquired from a 1.5 T MR-Linac. The training dataset contained abdominal MR images, DL contours, and their corresponding quality ratings, from 103 datasets. The quality of DLAS contours was determined using an in-house contour classification tool, which categorizes contours as acceptable or edit-required based on the expected editing effort. The performance of the 3D ACQA model was evaluated using an independent dataset of 34 abdominal MRIs, utilizing confusion matrices for true and predicted classes. Main results. The ACQA predicted ‘acceptable’ and ‘edit-required’ contours at 72.2% (91/126) and 83.6% (726/868) accuracy for pancreas, and at 71.2% (79/111) and 89.6% (772/862) for duodenum contours, respectively. The model successfully identified false positive (extra) and false negative (missing) DLAS contours at 93.75% (15/16) and %99.7 (438/439) accuracy for pancreas, and at 95% (57/60) and 98.9% (91/99) for duodenum, respectively. Significance. We developed 3D-ACQA models capable of quickly evaluating the quality of DLAS pancreas and duodenum contours on abdominal MRI. These models can be integrated into clinical workflow, facilitating efficient and consistent contour evaluation process in MRgOART for abdominal malignancies.
Bremsstrahlung radiation power in fusion plasmas revisited: towards accurate analytical fitting
Authors: Xie Huasheng
Published: October 2024

In fusion plasmas, where electron temperatures

T

e

range from keV to hundreds of keV, bremsstrahlung radiation constitutes a significant energy loss mechanism. While various thermal average fitting formulas exist in the literature, their accuracy is limited, particularly for

T

e

⩽
20

 keV with error

>
10
%

. Additionally, non-relativistic fitting formulas become invalid for

T

e

⩾
50

 keV. The accurate calculation of bremsstrahlung radiation is important for fusion gain study, especially of advanced fuels fusion. In this work, we develop new but still simple fitting formulas that are valid for electron temperatures ranging from small (

≲
0.1

 keV) to extreme relativistic range, with errors of less than 1% even for high atomic number ions (e.g. Z = 30), which could be sufficient for fusion plasma applications. Both electron–ion (e–i) and electron–electron (e–e) bremsstrahlung radiations are considered. Both polynomial fitting with truncated (

t
=

k

B

T

e

/

m

e

c
2

⩽
10

) and one-fit-all formulas are provided. Additionally, we offer fitting formulas for e–i and e–e specifically for electron energies, which could prove useful in non-Maxwellian bremsstrahlung radiation studies.
Enhancement of single-photon level signal detection based on phase sensitive amplification strategy
Authors: Zhang Changchang , Wang Zhaolu , Liu Hongjun , Huang Nan
Published: October 2024

We investigate the ability of phase-sensitive amplification (PSA) to noiselessly amplify the preferred quadrature components of single-photon signals that are limited by phase fluctuations relative to the pump. We present a PSA enhancement strategy that is more realistic for possible experimental realization and is expected to significantly improve the detection of weak signals at the single-photon level and obtain more useful information. Our study shows that with a large PSA gain, proper transmissivity allows both direct and balanced homodyne detections to operate optimally simultaneously, and effectively improves the noise figure degradation owing to the internal losses and non-ideal detection efficiency.
Inelastic resonant scattering of electrons on hydrogen-like ions
Authors: Vasileva D M , Lyashchenko K N , Andreev O Yu , Yu D
Published: October 2024

The inelastic electron scattering is one of the processes that must be understood in detail for the correct interpretation of astrophysical data. We suggest
ab initio
QED treatment of the inelastic scattering of quasi-free electrons on hydrogen-like ions with possible formation and subsequent decay of intermediate autoionizing states. We calculate the doubly differential cross sections for scattering on F8+, Ca19+ and Kr35+ in the range of energies where doubly excited

3
l
3
l
′

states are involved. The energies and widths of these states are presented.
PT-symmetric solitons in networks: a metric graph based approach
Authors: Akramov M , Eshchanov B , Khashimova F , Matrasulov D
Published: October 2024

We propose a model for networks approving PT-symmetric standing solitons. The model is described in terms of the nonlinear Schrödinger equation on metric graphs, with complex PT-symmetric potential given on each bond. Exact soliton solutions of the problem are obtained. The stability analysis of the PT-symmetric standing solitons on the star graph is studied. Extension for other graph topologies is demonstrated by considering a metric tree graph.
Tunable Fano resonances at 2 μm waveband based on a single microring resonator
Authors: Xu Qiang , Li Hongjian , Sun Shibo , Kong Mei , Xu Yameng
Published: October 2024

Development of silicon photonic devices for the 2 μm waveband is urgent since the 2 μm waveband has been considered as a potential communication window for next-generation optical communications. Asymmetric Fano resonances are very promising in the development of devices such as optical switches, sensors, and modulators for the 2 μm waveband. In this paper, a Fano resonance at the 2 μm waveband is theoretically realized by using a silicon-based microring resonator and the thermo-optic effect is employed to tune it. Utilizing this single microring resonator structure instead of the present coupled microring resonator structures, we achieve the Fano resonance with an extinction ratio of 30.5 dB and a slope ratio of 69.3 dB nm−1 at the 2 μm waveband. The metal heater and graphene heater are designed and optimized to achieve the Fano tuning. The thermal-optical tuning efficiencies are 0.46 nm mW−1, 0.61 nm mW−1 and 1 nm mW−1 for the metal heater, the metal heater with air adiabatic slots, and the graphene heater, respectively. This work provides an effective scheme for the formation and tuning of the Fano resonance at the 2 μm waveband, which is conducive to the development of devices and optical communication systems at the 2 μm waveband.
Laser modulation to plateau region and intensity of high-order harmonic generation in monolayer MoTe2
Authors: Ji Zhiqiang , Wu Chenglong , Liu Xiaoyu , Qiao Shiqian , Li Shasha , Bo Xiangyan , Pu Yong , Wu Hong , Li Feng
Published: October 2024

Through solving semiconductor Bloch equations, we theoretically investigated the high-order harmonic generation in monolayer MoTe2 under laser modulation. Adjusting the laser parameters, the plateau region and intensity of harmonics can be effectively regulated. Changing laser wavelength can regulate the width of platform region and the cutoff order of harmonic spectrum. Platform region widens with the increase of laser wavelength. Under different laser wavelengths, the number of photons that need to be absorbed for electron transition varies, which affects the inter-band transition of electrons. Laser vector potential also varies with the wavelength, affecting the intra-band motion of electrons. Laser field strength can significantly change the harmonic intensity. As the laser field strength increases, the harmonic intensity increases and may generate new plateau in the high-energy region. The emergence of new platform is due to the transition of electrons between conduction bands. Our work provides a theoretical exploration for generating high quality harmonics and understanding the micro mechanism of high-order harmonic generation.
Mechanical properties of TPDH-graphene: atomistic aspect
Authors: Peng Qing , Chen Gen , Huang Zeyu , Zhang Yuqiang , Zhang Xiaofan , Chen Xiao-Jia , Hu Zhongwei
Published: October 2024

TPDH-graphene is a new type of two-dimensional carbon material predicted by first-principles calculations to have tetragonal (T), pentagonal (P), decagonal (D) and hexagonal (H) carbon ring structures. First-principles calculations show that this special structure gives it excellent mechanical properties and promising applications in nanoelectronics. In this paper, a comprehensive test of its mechanical properties was carried out using the classical molecular dynamics (MD), mainly exploring the effects of factors such as tensile direction and temperature on its mechanical properties, and exploring the effects of introducing rectangular and circular defects on its mechanical properties. The results show that: TPDH-graphene exhibits significant anisotropy in zigzag and armchair directions, and the material exhibits some tensile toughness in armchair direction; the mechanical properties of the material are weakened at higher temperatures; the adding of defects leads to the reduction of the mechanical properties of the material in different directions to different degrees, and the The tensile toughness in the armchair direction is weakened by the addition of defects.
Spiral shaped highly sensitive rectangular PCF-based cancer cells detector in terahertz regime
Authors: Singh Jaydeep , Khamaru Akash , Kumar Ajeet
Published: October 2024

The increasing fatality rate of cancer in the modern world has become a global concern. To address this issue, early detection of cancer cells in human blood is essential. In this article, a rectangular spiral shaped photonic crystal fiber has been proposed for sensing cancer cells in terahertz regime. The proposed PCF based sensor features a square shaped core surrounded by rectangular air holes of different sizes in a spiral manner. Finite element method based COMSOL Multiphysics software has been used for the design and analysis of the model. The model is sensitive to refractive index variation for the identification of cancer cells. The values of effective refractive index, effective mode area, relative sensitivity, non-linearity, and confinement loss are obtained for MCF-7, MDA-MB-231, Jurkat, HeLa, Basal and PC-12. The PCF based sensor resulted in excellent results of relative sensitivity and Confinement loss as good as 99.377% and 8.59 × 10−12 dBm−1 respectively. Furthermore, the present PCF based sensor model is fabrication feasible, and we hope that it can be utilized at industrial level for biosensing applications in terahertz waveguide regime.
Experimental and numerical investigation of the Doppler-shifted resonance condition for high frequency Alfvén eigenmodes on ASDEX Upgrade
Authors: Ochoukov R. , Bilato R. , Bobkov V. , Faugel H. , Kappatou A. , Schneider P. , Weiland M. , Dreval M. , Sipilä S. , Dendy R. , Johnson T. , Kazakov Ye , McClements K.G. , Moseev D. , Salewski M. ,   ASDEX Upgrade Team,   EUROfusion Tokamak Exploitation Team
Published: October 2024

The Doppler-shifted resonance condition for high frequency Alfvénic eigenmodes has been extensively studied on ASDEX Upgrade in the presence of one or a combination of two neutral beam injected (NBI) fast ion populations. In general, only centrally deposited NBI sources drive these modes, while off-axis sources globally stabilize the mode activity. For the case of a single central NBI source, the observed trend is: the highest frequency modes are driven by the lowest energy and lowest pitch angle NBI sources, in line with the expectation from the Doppler-shifted resonance condition. The expected mode frequencies are determined analytically from the two-fluid cold plasma dispersion relation and the most unstable frequency relation, while the mode growth rates are estimated using the fast ion slowing down distribution functions from the ASCOT code. The overall mode frequency trend in a source-to-source variation is tracked, although a systematic overestimate of ∼1 MHz is observed. Possible causes of this overestimate include the finite size of the resonant fast ion drift orbit and non-linear effects such as mode sideband formation. Alternatively, the expected mode frequencies are determined by tracking the growth rate maxima trajectories, this method improves the agreement with the experimentally measured values. A combination of two central mode-driving NBI sources results in the suppression of the mode driven by the lowest energy and the lowest pitch angle NBI source. Computing the analytically expected mode frequency following the method outlined above, again, generally tracks the experimentally observed trend. The mode’s Alfvénic nature allows for a practical application to track the core hydrogen fraction by following the mode frequency changes in response to a varying ion mass density. Such application is demonstrated in a discharge where the average ion mass is varied from ∼2m
p to ∼1.5m
p (where m
p is the proton mass) via a hydrogen puff in a deuterium plasma, in the presence of a strong mode activity. The expected mode frequency changes are computed from the existence of the resonance condition, and the values track the measured results with an offset of ∼0.5 MHz. Overall, the results suggest an intriguing possibility to monitor and control the D-T ion fraction in the core of a fusion reactor in real time using a non-invasive diagnostic.
Dynamics analysis and verification for slotted limited-angle torque motor in electromagnetic valve applications
Authors: Cheng Xin , Tao Peng , Han Ping , Zhou Rougang , Zhu Junjie
Published: October 2024

Limited-angle torque motor (LATM) as a key component of the exhaust gas recirculation (EGR) valve, which can precisely control the position of the EGR valve, thus achieving dynamic adjust the amount of exhaust gas recirculation. This paper introduces the dynamic analysis, modelling and experimental validation of a concentrated winding axial-flux slotted LTAM with 4-poles/4-slots. Aiming at the prominent issues such as cogging torque and nonlinear torque characteristics in the operating region of slotted LATMs, analytical equations are derived based on the magnetic circuit to predict the torque-angle characteristics of LATM, covering both constant torque and linear torque regions. These equations help establish the relationship between performance and key parameters, enabling rapid design of LATM. The test results indicate that the proposed model can accurately describe the electromagnetic torque and cogging torque of the LTAM, with an error range of 5%. Utilizing the effective angle range proposed in this paper, an approximate linear relationship between the electromagnetic torque and current can be achieved, with a linear error of 6%.