bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic screening in zebrafish larvae identifies promising cyanobacterial strains and pheophorbide a as insulin mimetics
Authors: Ribeiro Tiago , Reis Mariana , Vasconcelos Vitor , Urbatzka Ralph
Published: December 2024

Diabetes is a pandemic disease that causes the loss of control of glucose regulation in the organism, in consequence of dysfunction of insulin production or functionality. In this work, the antidiabetic bioactivity of 182 fractions from 19 cyanobacteria strains derived from the LEGE Culture Collection were analysed using the 2-NBDG assay in zebrafish larvae. From this initial screening, two fractions (57 (06104_D) and 107 (03283_B)) were identified as promising insulin mimetics. These were further characterized by measuring glucose levels in whole larvae, the expression of glucose transporters (GLUT 1–3) using western blot, and the mRNA expression levels of the glut2, pepck, and insa genes using real-time qPCR. Both fractions showed a decrease in free glucose levels. Furthermore, exposure to fraction 06104_D decreased GLUT1 and increased insa mRNA levels. The chemical composition of these fractions was determined using LC-HRESIMS/MS and compared to inactive fractions of the same polarity in order to identify the unique bioactive molecules. The molecular networks constructed using the GNPS platform revealed that fraction 06104_D contained mass clusters primarily composed of chlorins, lipids, and terpenoids, while fraction 03283_B contained xanthophylls, peptides, and terpenoids. To correlate the observed activity with the chemical composition of fraction 06104_D, pheophorbide a was chosen as a representative of chlorophyll derivatives. Exposure to zebrafish larvae at 10 and 20 µM confirmed the increased glucose uptake on the 2-NBDG assay. These findings highlight the bioactivity of chlorophyll derivatives as insulin mimetic compounds, as well as cyanobacteria as a source of potential therapeutic diabetes applications.
Personalized modeling of gut microbiome metabolism throughout the first year of life
Authors: Shaaban Rola , Busi Susheel Bhanu , Wilmes Paul , Guéant Jean-Louis , Heinken Almut
Published: December 2024

Background

Early-life exposures including diet, and the gut microbiome have been proposed to predispose infants towards multifactorial diseases later in life. Delivery via Cesarian section disrupts the establishment of the gut microbiome and has been associated with negative long-term outcomes. Here, we hypothesize that Cesarian section delivery alters not only the composition of the developing infant gut microbiome but also its metabolic capabilities. To test this, we developed a metabolic modeling workflow targeting the infant gut microbiome.

Methods

The AGORA2 resource of human microbial genome-scale reconstructions was expanded with a human milk oligosaccharide degradation module. Personalized metabolic modeling of the gut microbiome was performed for a cohort of 20 infants at four time points during the first year of life as well as for 13 maternal gut microbiome samples.

Results

Here we show that at the earliest stages, the gut microbiomes of infants delivered through Cesarian section are depleted in their metabolic capabilities compared with vaginal delivery. Various metabolites such as fermentation products, human milk oligosaccharide degradation products, and amino acids are depleted in Cesarian section delivery gut microbiomes. Compared with maternal gut microbiomes, infant gut microbiomes produce less butyrate but more L-lactate and are enriched in the potential to synthesize B-vitamins.

Conclusions

Our simulations elucidate the metabolic capabilities of the infant gut microbiome demonstrating they are altered in Cesarian section delivery at the earliest time points. Our workflow can be readily applied to other cohorts to evaluate the effect of feeding type, or maternal factors such as diet on host-gut microbiome inactions in early life.
Structurally programmable, functionally tuneable dendrimers in biomedical applications
Authors: Prakash Geethu , Parmar Bhagyesh , Bhatia Dhiraj
Published: December 2024

The application of nanotechnology in medical biology has seen a significant rise in recent years because of the introduction of novel tools that include supramolecular systems, complexes, and composites.
Redox-induced dimerisations of a phosphacyclic biradicaloid
Authors: Zuber David , Storcheva Oksana , Lüdtke Karsten Paul , Brunk Leonidas , Coburger Peter
Published: December 2024

Reduction and oxidation of a phosphacyclic biradicaloid leads to reactive radical species which undergo selective dimerisation reactions.
Layer-by-layer thin films of Ti3C2 MXene and gold nanoparticles as an ideal SERS platform
Authors: Mazlumoglu Hayrunnisa , Yilmaz Mehmet
Published: December 2024

The combination of plasmonic metals and MXene, as a new and interesting member of the 2D material class, may provide unique advantages in terms of low cost, versatility, flexibility, and improved activity as an ideal SERS platform.
Immobilization and electroactive switching of bovine serum albumin on polypyrrole functionalized bioelectroactive surfaces
Authors: Cao Danfeng , Jafari Mohammad Javad , Hultin Erik , Nordin Anton , Rönnqvist Jacob , Yuan Yusheng , Rörby Emma , Jönsson Jan-Ingvar , Ederth Thomas , Martinez Jose G. , Jager Edwin W. H.
Published: December 2024

Bovine serum albumin (BSA) was covalently bound to different carboxyl-modified polypyrroles and electrochemically switched. It was found that the immobilized BSA could change its presentation depending on carboxyl modification and the redox state.
Atom-efficient chlorinative dearomatization of naphthol, quinolinol, and isoquinolinol derivatives using trichloroisocyanuric acid (TCCA)
Authors: Caudle Jenna D. , Ennis Marlow K. , Dodge Dillon C. , Iskandar Audrey A. , Portillo Urquiza Yesenia , Seo David K. , Wright Franklyn M. , Purser Gordon H. , Leonori Daniele , Lamar Angus A.
Published: December 2024

A new atom-economical method for chlorinative dearomatization of arenols and heteroarenols has been developed. The production of 27 dearomatized compounds in yields ranging from 38 to 98% is reported.
Residence time distribution effects on continuous-flow reaction in a polymer gel-based porous monolith: investigation of an asymmetric reaction with supported Hayashi–Jørgensen catalysts
Authors: Shigeeda Harutaka , Matsumoto Hikaru , Nagao Masanori , Miura Yoshiko
Published: December 2024

Polymer gel porous monoliths with Hayashi–Jørgensen catalyst are developed for flow asymmetric reactions. Lower cross-linked gel monoliths showed narrow residence time distribution and fast molecular diffusion for high catalytic performance.
Delafossite-based electrode materials: design, synthesis and their application in electrocatalysis
Authors: Cheng Zhixiang , Zhu Junpeng , Xu Xiaoxue , Tan Yufan , Gao Ze , Li Qiangwei , Liu Juzhe , Wang Lidong
Published: December 2024

This review outlines the design principles of delafossite and their electrocatalytic applications. Further insights and perspectives on the challenges and opportunities for developing delafossite-based advanced electrocatalysts are also provided.
Synthesis of phenanthroimidazole-based host materials with balanced hole–electron transport for highly efficient blue fluorescent OLEDs
Authors: Wang Zhiqiang , Zhang Bohua , Chen Yi , Pei Jiangxue , Jia Qingyu , Hao Chaobo , Lei Xiping , Wang Dongdong
Published: December 2024

Three new U-shaped host materials, namely, DPPI-DBF, Cz-PPI-DBF and TPA-PPI-DBF, were designed and synthesized by employing a dibenzofuran bridge linker combining one phenanthroimidazole (PPI) unit with PPI/carbazole (Cz)/triphenylamine (TPA) units.
Accelerated derivative-free spectral residual method for nonlinear systems of equations
Authors: Birgin Ernesto G. , Gardenghi John L. , Marcondes Diaulas S. , Martínez José Mario
Published: December 2024

Many continuous models of natural phenomena require the solution of large-scale nonlinear systems of equations. For example, the discretization of many partial differential equations, which are widely used in physics, chemistry, and engineering, requires the solution of subproblems in which a nonlinear algebraic system has to be addressed, especially one in which stable implicit difference schemes are used. Spectral residual methods are powerful tools for solving nonlinear systems of equations without derivatives. In a recent paper [Birgin and Martínez, SIAM J. Numer. Anal. 60 (2022) 3145–3180], it was shown that an acceleration technique based on the Sequential Secant Method can greatly improve its efficiency and robustness. In the present work, an R implementation of the method is presented. Numerical experiments with a widely used test bed compare the presented approach with its plain (i.e., non-accelerated) version that is part of the R package BB. Additional numerical experiments compare the proposed method with NITSOL, a state-of-the-art solver for nonlinear systems. These comparisons show that the acceleration process greatly improves the robustness of its counterpart included in the existing R package. As a by-product, an interface is provided between R and the consolidated CUTEst collection, which contains over a thousand nonlinear programming problems of all types and represents a standard for evaluating the performance of optimization methods.
A brief introduction to the diffusion Monte Carlo method and the fixed-node approximation
Authors: Annarelli Alfonso , Alfè Dario , Zen Andrea
Published: December 2024

Quantum Monte Carlo (QMC) methods represent a powerful family of computational techniques for tackling complex quantum many-body problems and performing calculations of stationary state properties. QMC is among the most accurate and powerful approaches to the study of electronic structure, but its application is often hindered by a steep learning curve; hence it is rarely addressed in undergraduate and postgraduate classes. This tutorial is a step toward filling this gap. We offer an introduction to the diffusion Monte Carlo (DMC) method, which aims to solve the imaginary time Schrödinger equation through stochastic sampling of the configuration space. Starting from the theoretical foundations, the discussion leads naturally to the formulation of a step-by-step algorithm. To illustrate how the method works in simplified scenarios, examples such as the harmonic oscillator and the hydrogen atom are provided. The discussion extends to the fixed-node approximation, a crucial approach for addressing the fermionic sign problem in multi-electron systems. In particular, we examine the influence of trial wave function nodal surfaces on the accuracy of DMC energy by evaluating results from a non-interacting two-fermion system. Extending the method to excited states is feasible in principle, but some additional considerations are needed, supported by practical insights. By addressing the fundamental concepts from a hands-on perspective, we hope this tutorial will serve as a valuable guide for researchers and students approaching DMC for the first time.
A compact and fast radio-frequency source for efficient Raman sideband cooling
Authors: Pang Liren , Ma Zhiyu , Wang Biao , Gong Rui , Wei Songquan , Liu Hongli , Yuan Wenhao , Deng Ke , Zhang Jie , Lu Zehuang
Published: December 2024

A compact and fast radio-frequency (RF) source developed for Raman sideband cooling (RSBC) in trapped ion and cold atom experiments is presented. The source is based on direct digital synthesizer, advanced real-time infrastructure for quantum physics, and field programmable gate array. The source has a frequency switching speed of 40 ns and can output continuous μs-level time sequences for RSBC. The maximum output frequency of the source is 1.4 GHz. The RF source is capable of pre-writing data for eight channels. As a demonstration, the RF source is applied to our 25Mg+–27Al+ ion pair optical clock experiment. In order to cool down the ion pair to the vibrational ground state, two-order RSBC is applied to the 25Mg+ ion. As a result, the ion pair motions in the three X, Y, and Z directions are all cooled to the vibrational ground state efficiently, demonstrating the feasibility of this technique. The developed RF source can be widely implemented for other cold atom experiments.
Photon-mediated energy transfer between molecules and atoms in a cavity: A numerical study
Authors: Zhang Jun , Wang Shaohong , Guo Mengdi , Li Xin-Ke , Xiong Yong-Chen , Zhou Wanghuai
Published: December 2024

The molecular energy transfer is crucial for many different physicochemical processes. The efficiency of traditional resonance energy transfer relies on dipole–dipole distance between molecules and becomes negligible when the distance is larger than ∼10 nm, which is difficult to overcome. Cavity polariton, formed when placing molecules inside the cavity, is a promising way to surmount the distance limit. By hybridizing a two-level atom (TLA) and a lithium fluoride (LiF) molecule with a cavity, we numerically simulate the reaction process and the energy transfer between them. Our results show that the TLA can induce a deep potential well, which can be seen as a replica of the potential energy surface of bare LiF, acting as a reservoir to absorb/release the molecular kinetic energy. In addition, the energy transfer shows a molecular nuclear kinetic energy dependent behavior, namely, more nuclear kinetic energy igniting more energy transfer. These findings show us a promising way to manipulate the energy transfer process within the cavity using an intentional TLA, which can also serve as a knob to control the reaction process.
Electronic states of the N2+ ion dissociating to the four lowest dissociation limits: Energies, transition dipole moments, and Einstein coefficients
Authors: Hammami Chaima , Penson Conner , Ayouz Mehdi Adrien , Kokoouline Viatcheslav
Published: December 2024

This study presents Born–Oppenheimer energies and transition dipole moments of the 36 lowest electronic states of the N2+ ion as a function of internuclear distance in the interval between 1.5 and 10 bohrs obtained in first-principles calculations. The electronic states are of the total electronic spin S = 1/2, 3/2, and 5/2, dissociating toward to the lowest four N(4S0) + N+(3P), N(2P0) + N+(3P), N(2D0) + N+(3P), and N(4S0) + N+(1D) dissociation limits. Energies of the lowest states, dissociating toward to the N(4S0) + N+(3P) limit, are computed accounting for relativistic corrections. The obtained potential energy curves and the transition dipole moments are employed to compute vibrational energies in these states, vibronic transition dipole moments, and the Einstein coefficients for radiative transitions between the vibronic levels.
Variance-reduced random batch Langevin dynamics
Authors: Xu Zhenli , Zhao Yue , Zhou Qi
Published: December 2024

The random batch method is advantageous in accelerating force calculations in particle simulations, but it poses a challenge of removing the artificial heating effect in application to the Langevin dynamics. We develop an approach to solve this issue by estimating the force variance, resulting in a variance-reduced random batch Langevin dynamics. Theoretical analysis shows the high-order local truncation error of the time step in the numerical discretization scheme, consistent with the fluctuation–dissipation theorem. The numerical results indicate that the method can achieve a significant variance reduction since a smaller batch size provides accurate approximation, demonstrating the attractive feature of the variance-reduced random batch method for Langevin dynamics.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: December 2024

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials that supersede earlier data or suggest new research applications.
A proposal for skyrmion-based diode-like device in antiferromagnetic nanostripe
Authors: Silva R C , Silva R L
Published: December 2024

Micromagnetic simulations were employed to investigate the dynamics of a single skyrmion within an antiferromagnetic (AFM) nanostripe with spatially engineered magnetic properties. This study investigates skyrmion motion within an AFM nanostripe engineered with trapezoidal regions of enhanced magnetic anisotropy, enabling diode-like functionality by selectively directing skyrmion movement. Our findings demonstrate that skyrmions can cross these barriers in one direction while being obstructed in the reverse direction, mimicking diode behavior. A detailed analysis is presented on how geometric parameters, such as the inclination angle of the trapezoidal barriers, impact skyrmion motion and device efficacy. Additionally, we reveal that an optimal combination of current density and anisotropy is essential to facilitate efficient skyrmion transport through the nanostripe without reverse movement or annihilation. This work advances the development of skyrmion-based devices for spintronic applications. It provides valuable insights into designing structures that harness controlled topological dynamics.
Exploring the correlation between chemical bonding and structural distortions in TbCu0.33Te2
Authors: Weinelt Leander , Steinberg Simon
Published: December 2024

The design of solid-state materials requests a thorough understanding of the structural preferences among plausible structure models. Since the bond energy contributes to the formation energy of a given structure model, it also is decisive to determine the nature of chemical bonding for a given material. In this context, we were motivated to explore the correlation between chemical bonding and structural distortions within the low-dimensional tellurium fragments in TbCu0.33Te2. The ternary telluride was obtained from high-temperature solid-state reactions, while structure determinations based on x-ray diffraction experiments did not point to the presence of any structural distortion above 100 K. However, the results of first-principles-based computations indicate that a potential structural distortion within the low-dimensional tellurium fragments also correlates to an optimization of overall bonding.
The properties of solids: ‘If you want to understand function, study structure’
Authors: Jones R O
Published: December 2024

The importance of the structure-function relationship in molecular biology was confirmed dramatically by the recent award of the 2024 Nobel Prize in Chemistry ‘for computational protein design’ and ‘for protein structure prediction’. The relationship is also important in chemistry and condensed matter physics, and we survey here structural concepts that have been developed over the past century, particularly in chemistry. As an example we take structural phase transitions in phase-change materials (PCM), which can be switched rapidly and reversibly between amorphous and crystalline states. Alloys of Ge, Sb, and Te are the materials of choice for PCM optical memory; they satisfy practical demands of stability and rapid crystallization, which results in metastable, rock salt structures, not the most stable (layered) crystalline forms.
Josephson diode effect in one-dimensional quantum wires connected to superconductors with mixed singlet-triplet pairing
Authors: Soori Abhiram
Published: December 2024

The Josephson diode effect (JDE), characterized by asymmetric critical currents in a Josephson junction, has drawn considerable attention in the field of condensed matter physics. We investigate the conditions under which JDE can manifest in a one-dimensional Josephson junction composed of a spin–orbit-coupled quantum wire with an applied Zeeman field, connected between two superconductors (SCs). Our study reveals that while spin–orbit coupling (SOC) and a Zeeman field in the quantum wire are not sufficient to induce JDE when the SCs are purely singlet, introduction of triplet pairing in the SCs leads to the emergence of JDE. This finding highlights the potential of JDE as a probe for triplet superconductivity. We further demonstrate that even in absence of SOC in the quantum wire, JDE can arise when the directions of the triplet pairing and the Zeeman field are non-collinear, provided the SCs exhibit mixed singlet–triplet pairing. Additionally, we identify specific conditions under which JDE is absent, namely, when the pairing is purely triplet and the directions of the SOC and the triplet pairing are perpendicular. Our findings indicate that JDE is always accompanied by anomalous Josephson effect. The diode effect coefficient is found to oscillate with variations in the chemical potential of the quantum wire, driven by Fabry–Pérot interference effects. Our results suggest that quantum wires connected across SCs can serve as effective platforms for probing triplet superconductivity through the observation of JDE.
Synchronous detection of multiple micro-substances with a single output channel using a weakly coupled resonator array
Authors: Liu Xiaohe , Wang Jiansong , Zhao Zhujie , Zhang Lijia , Song Jie , Xia Yuanlin , He Liang , Wang Dong F , Wang Zhuqing , Xia Cao
Published: December 2024

In this paper, a multiple micro-substances sensing scheme with a single output channel using a weakly coupled resonator array is proposed. An analytical model of the resonator using the Euler–Bernoulli beam theory has been developed, as well as the dynamic behavior has been further explored using the Galerkin method. We have discovered numerically that, in the weakly coupled cantilever array, the A-f (amplitude-frequency) curve of any cantilever physically reflects the vibration features of other cantilevers. Hence, by measuring the output signal of a single cantilever, multiple substances applied on each cantilever respectively can be identified and detected synchronously. A single output channel via a weakly coupled micro-resonator array is constructed and validated numerically for picogram level mass detection. Equivalent experiments with a macro coupled five-cantilever array have been further conducted for verification. Under a common sweep-driven signal, the five analytes applied on each cantilever with masses at microgram level can be detected synchronously and independently by measuring the frequency shifts of the five resonant peaks of the center cantilever. Multiple substances sensing with a single output channel and a single driving signal is thus realized with low relative errors and high linearities. By enhancing the driving voltage, the mass resolution can also be improved via Duffing bifurcation. This work not only reveals a new coupled vibration behavior but also provides a new avenue for multiple analytes detection.
Orthogonal time division modulation for nonlinear frequency-scanning interferometry and phase extraction
Authors: Tian Kai , Guo Junkang , Yu Yuqi , Wang Zian , Liu Zhigang
Published: December 2024

Frequency-scanning interferometry (FSI) is an absolute distance measurement method, and its measurement accuracy is affected by the nonlinearity of laser frequency scanning. To improve the accuracy of phase extraction of the nonlinear interference signal corresponding to nonlinear frequency scanning, this paper builds an FSI measurement system that performs orthogonal time division modulation on a reference optical path laser. By orthogonal time division modulation of the reference laser, a theoretical orthogonal interference signal is obtained through time-division multiplexing, and an instantaneous phase extraction method is proposed. However, due to the time division of the two signals, a orthogonal phase deviation is introduced. By theoretically analyzing the phase solution results when there is a orthogonal phase deviation, the error type can be determined and suppressed. Finally, the effectiveness of this method is verified by experiments.
CMFE-PVT: a lightweight fault diagnosis framework for rolling bearings using compact multi-scale feature extraction and a pruned-restructured vision transformer
Authors: Ding Shanshan , Wu Weibing , Ma Xiaolu , Liu Fei , Chen Renwen
Published: December 2024

The intelligent fault diagnosis method based on transformer and convolutional neural network (CNN) has achieved good global and local feature extraction results. However, the multi-head self-attention mechanism adopted by the transformer and the cross-channel convolution operation in CNN increases the complexity of the model, thereby increasing the demand for hardware resources, which to some extent, limits its broad applicability in industrial applications. Therefore, this paper proposes a lightweight fault diagnosis framework based on compact multi-scale feature extraction and pruned-restructured vision transformer (ViT) to address the above challenges. Firstly, a compact multi-scale feature extraction module is designed to efficiently capture complex features in rolling bearing vibration signals through parallel multi-scale convolution kernels, combined with channel reduction strategies to significantly reduce computational complexity while maintaining feature richness. Next, short-time Fourier transform and pseudo-color processing techniques are used to obtain time–frequency images. Then, a dual optimization of matrix sparsity and structural reorganization is implemented for Self-attention in ViT to ensure model performance and significantly reduce computational overhead. Finally, the time–frequency images are segmented and rearranged before being fed into the improved lightweight ViT for global feature extraction and fault recognition of rolling bearings. The experimental results show that the proposed fault diagnosis method has the advantages of lightweight (Params:4.27 K, floating point operations per seconds:0.1 M, multiplication and accumulation operations per seconds:51.07 K) and robustness compared to mainstream algorithms.
Gold nanomaterials capped with bovine serum albumin for cell and extracellular vesicle imaging
Authors: Wu Re-Wen , Lin Yu-Han , Lu Cheng-Hsiu , Su Chia-Hao , Chen Yu-Shan , Wang Feng-Sheng , Lian Wei-Shiung
Published: December 2024

Bovine serum albumin-capped gold nanoclusters (AuNC@BSA) are ionic, ultra-small, and eco-friendly nanomaterials that exhibit red fluorescence emission. Upon modification, these nanomaterials can serve as imaging probes with multimodal functionality. Owing to their nanoscale properties, AuNC@BSA-based nanomaterials can be readily endocytosed by cells for imaging. With the increasing interest in cell therapy, extracellular vesicles (EVs) have attracted considerable attention from researchers; however, effective methods for imaging EVs remain limited. Although several studies have explored imaging strategies for cells and EVs using compounds, nuclear pharmaceuticals, nanoparticles, or genetic constructs, the use of AuNC@BSA-based nanomaterials for labeling EVs and their parental cells has rarely been discussed, with even less attention paid to their multimodal potential. To address this gap, we utilized three types of AuNC@BSA-based derivatives: AuNC@BSA, AuNC@BSA-Gd, and AuNC@BSA-Gd-I. Our findings demonstrate that these derivatives can effectively label both cells and EVs using a simple direct labeling approach, which is particularly notable for EVs, as they typically require more complex labeling procedures. Furthermore, the multimodal potential of labeled cells and EVs was evaluated, revealing their capabilities for multimodal imaging. In summary, this study presents an effective strategy for labeling EVs and their parental cells using multimodal nanomaterials. These findings will contribute to accelerating the development of drug delivery systems, cell- and EV-based therapies, and advanced imaging strategies.
Investigations of modulation method and stress mechanism for the growth of AlGaN channel heterostructures
Authors: Wang Baiqi , Zhang Yachao , Xu Shengrui , Yao Yixin , Liu Wenjun , Du Chenglin , Cai Xiaolong , Wu Sheng , Liu Haijun , Zhang Yu , Tang Xue , Zhang Jincheng , Hao Yue
Published: December 2024

In this work, the strong connection between the channel and the barrier layer of AlGaN channel heterostructures has been investigated in detail. Unlike GaN as a channel material, AlGaN channel layers significantly influence the transport characteristics and quality of AlGaN barrier layers with increasing Al composition. Furthermore, the stress mechanism in the growth of the AlGaN layer has been thoroughly discussed. It has been revealed that the modulation of the channel layer stress alters its relaxation and enhances the consistency of the in-plane lattice constant, thereby improving channel layer quality. Moreover, this process reduces the tensile stress on the barrier layer, and improves the barrier layer quality and heterostructures performance. This work is not only beneficial for the achievement of high breakdown voltage and new generations of high-power RF devices, but is also instructive to the optimization and realization of the AlGaN material in deep-UV devices.
Determination of Schrödinger nonlinearities from the scattering map
Authors: Killip Rowan , Murphy Jason , Visan Monica
Published: December 2024

We prove that the small-data scattering map uniquely determines the nonlinearity for a wide class of gauge-invariant, intercritical nonlinear Schrödinger equations. We use the Born approximation to reduce the analysis to a deconvolution problem involving the distribution function for linear Schrödinger solutions. We then solve this deconvolution problem using the Beurling–Lax Theorem.
Optimization study of acoustic characteristics for assembled curled structure
Authors: Yang Mengchun , Zhao Jinyu , Liu Zihao , Gong Shulei , Liu Yuan , Li Yongchang , Zhang Donghui
Published: December 2024

In this paper, a simple curled G-type structure is used as the basic unit, which is coded according to its different opening directions, and a composite structure model with special acoustic functions is constructed by different types of assembly methods. The curled G-structure as the basic unit has the characteristics of a Helmholtz resonator, which can resonate at a specific frequency and effectively attenuate the acoustic energy. In the

2
×
2

matrix assembly, there exists an optimal model with an ultra-wide forbidden bandwidth of 510 – 2120 Hz, which also has a high degree of symmetry and the bandgap characteristics of phononic crystals. In the

1
×
N

matrix assembly, the optimization is performed by genetic algorithm, and N is taken as 4 to achieve tunable acoustic focusing. The simplicity of the curled G-type structure and the simple assembly method make the resulting composite structure have a wide range of potential applications in areas such as noise reduction and imaging.
A novel expansion method and its application to two nonlinear evolution equations arising in ocean engineering
Authors: Swati  , Prakash Amit
Published: December 2024

Nonlinear evolution equations are unavoidable for precisely modelling and understanding nonlinear wave phenomena. The study of nonlinear waves enriches our comprehension of natural phenomena and supports technological advancements across various disciplines. In this work, we have proposed a new expansion method to find the travelling wave solutions of nonlinear evolution equations. This method is named as

F

μ
F
+
G

−

expansion method. We applied the proposed technique to construct the exact travelling wave solutions to two well-known nonlinear equations arising in ocean engineering. These equations are extended (2 + 1)-dimensional Boussinesq equation and (3 + 1)-dimensional generalized shallow water wave equation. Propagation of obtained travelling wave solutions are illustrated by surface plots and two-dimensional graphs plotted for suitable parametric values. We observed soliton, kink, breather, lump and periodic wave structures. The results show efficiency and reliability of the proposed method.
Graphene and post-transition metal sulfide-based photodetectors for enhanced visible light photodetection: A review
Authors: Ameer Muhammad Faizan , Hussain Muzamil , Abbas Kashif , Sufyan Muhammad , Khan Sami Ullah , Kolsi Lioua
Published: December 2024

Integrating graphene and post-transition metal sulfides (PTMSs) enables enhanced photodetection in the visible spectrum regime, offering a remarkable strategy for next-generation photodetectors. This review summarizes the various characteristics of graphene/PTMSs-based photodetectors. The multiple aspects of photodetectors such as photodetection mechanism, performance parameters, and strategies for enhancing the properties of graphene-based photodetectors are briefly discussed. The photodetector characteristics of PTMSs and their suitability for integrating with graphene-based structures were highlighted. The performance of various graphene/PTMSs photodetectors was analyzed. This review will help optimize the integration of the properties of innovative graphene/PTMS structures.
UV aging effect on buckling properties of nanoclay particulated intraply hybrid composites
Authors: Oğuz Zeynal Abidin
Published: December 2024

This work experimentally investigated how ultraviolet (UV) aging affects the buckling properties of polymer-based intraply hybrid composites reinforced with nanoparticles (NPs) and varied in weight ratios. The nanoclay reinforced intraply carbon/aramid/epoxy composite samples with six different weight ratios of nanoparticles (0, 0.5, 1, 1.5, 2, 3%) were subjected to axial and lateral buckling tests after 250 h and 500 h of UV aging. At the end of the study, SEM images were taken for both buckling types and the damage patterns of the composite materials were analyzed. Considering the unaged samples, the critical buckling load (Pcr) of hybrid composites with NP reinforcement reached the highest values for 1% wt, with increases of 22.28 and 25.98% for the axial and lateral buckling test, respectively. The addition of more particles by weight resulted in a gradual decrease in the Pcr for both buckling tests. The Pcr decreases for axial and lateral buckling tests of unaged samples with 3 wt% nanoparticle reinforcement were found to be 8.18% and 25.43%, respectively. Experimental results showed that the buckling features of intraply samples changed due to both UV exposure and the addition of NPs. Furthermore, as UV exposure time increases, the Pcr for each weight ratio increased for both buckling types. Considering the UV effect, the axial Pcr increased by 32.07% and 40.89% in 1%wt particle reinforced samples after 250 and 500 h of UV aging, respectively. Similarly, an increase of 32.65% and 42.32% in lateral Pcr was observed in 1%wt particle reinforced samples after 250 and 500 h of UV aging, respectively. Finally, SEM images revealed matrix cracks, fiber breakage, debris, microbuckled fiber, and delamination mode failure morphologies.
A novel numerical approach for solving generalized fractional Fisher's equation
Authors: Walickta Singkai Chou , Kumar Saha Utpal
Published: December 2024

This paper aims to construct a novel numerical technique, the General Transform Adomian Decomposition Method (GTADM), for obtaining approximate solutions of fractional generalized Fisher's equation (FGFE). The fractional order is in the sense of Caputo. By applying the General transform(GT) and its inverse, the fractional Fisher equation is simplified within the GT domain, facilitating the treatment of the equation without imposing restrictive assumptions on the variables, then we apply the Adomian Decomposition Method(ADM) to solve the newly obtained equation. Stability analysis is conducted to enhance the theoretical framework. The GTADM requires less computational work and exhibits faster convergence without discretization, linearization, or perturbation, thus preserving the integrity of the FGFE. A comparative analysis with ADM, homotopy perturbation Sumudu transforms method (HPSTM), and q-homotopy analysis transform method (q-HATM) is performed to demonstrate the efficiency and robustness of GTADM. The accuracy and reliability of the GTADM are validated through the computation of absolute and relative errors. Furthermore, 2D and 3D graphical representations, generated using Maple 21 and MATLAB to support this work. The numerical results and graphs clearly demonstrate the efficiency and robustness of the GTADM.
Integration of a compact multiband antenna with CubeSat systems for efficient remote sensing and space applications
Authors: Aydin Emine Avşar , Kekil Serkan
Published: December 2024

This study investigates a compact multiband antenna integrated with a CubeSat optical system for remote sensing tasks. The proposed antenna is designed and analyzed using the CST Microwave Studio simulation environment. The results on the antenna performance are found to be quite good. Furthermore, the contribution of the FSS structure is investigated and analyzed by mounting it on a 1U CubeSat chassis made of PEEK material. A distinctive feature of the antenna is its compact design, ease of fabrication, and low cost, which are made possible by the advantages of TPU filaments that can be produced using a 3D printer. The antenna can be mounted on the tip of the nanosatellite together with the camera, providing space for solar panels or other equipment without using additional space in the side areas. Given the limited dimensions of CubeSats, our antenna makes efficient use of the surface. The antenna operates in the S, C, X, Ku, K, and Ka bands and achieves gains of 6.31, 4.08, 9.97, 7.06, 7.12, and 8.22 dBi, respectively; the reflection coefficient is much lower than −10 dB, and the VSWR value is below 1.5. In summary, the microstrip patch antenna system proposed in this work can be used in similar CubeSat remote sensing applications, offering excellent performance, reliability, simplicity, and compact dimensions in the fabrication and deployment system. In the future, we plan to perform fabrication and space environment testing of the proposed antenna, such as vibration, thermal vacuum cycling, and thermal shock.
Modeling and analysis of traffic flow considering drivers’ attention allocation between anticipated and recommended speeds
Authors: Rong Ying , Tang Nianbei , Xue Gang , Li Feng , Lan Ziqin
Published: December 2024

To study the impact of driver attention allocation between anticipated and recommended speeds in traffic flow systems, an improved model is proposed based on the logical framework of microscopic car-following model. The linear stability analysis theory was applied to analyze and derive the stability conditions. A numerical simulation was conducted to verify these theoretical findings. Subsequently, the VT-Micro model, which is widely used for energy consumption and emissions analysis was introduced to further study the effect of the driver’s attention allocation on the vehicle’s energy consumption. The results showed that drivers paying more attention to the recommended speed while driving would be conducive to the stability of traffic flow and reduce the average energy consumption of vehicles. From the perspective of speed guidance, when recommending the speed to the driver, the higher the attention paid to the real-time dynamic speed as the guide speed, the more it would disrupt the stability of road traffic flow and the less conducive it is to the control of vehicle energy consumption. These observations may provide a new perspective for understanding driver behavior and managing road traffic flow systems.
The role of RF sputtering parameters on the uniformity and stability of Tb4O7 thin films on silicon substrates for passivation applications
Authors: Sifawa Abubakar A , Mohammad Sabah M , Iliyasu Usman , Abdullah Mundzir , Shahrier Md Rumon , Soomro Aijaz Ali , Naser Hameed
Published: December 2024

In this study, the effects of different radio frequency (RF) parameters, were studied from the physical perspective of terbium oxide (Tb4O7) thin films deposited on silicon (Si) substrates, emphasizing their uniformity and stability for passivation applications. The findings for sample C, indicate that an optimal sputtering power of 110 W for 40 min enhances film uniformity while minimizing surface roughness, which is critical for achieving a stable passivation film. Notably, all the studied samples revealed a crystalline nature and maintained a stable phase, with no impurities detected from the grazing incident x-ray diffraction (GIXRD) patterns. Sample C revealed the highest value of crystallite size measured at 38 nm. Additionally, band gap energy (Eg) values between 2.19 and 2.78 eV were measured using the Kubelka–Munk (K-M) method. Photoluminescence (PL) analysis showed sample C achieved the highest peak intensity at 548 nm, corresponding to the 5D4 → 7F5 transition. Studies have been conducted on the formation of Tb4O7 thin films deposited by RF sputtering on Si substrates, annealed in an argon (Ar) atmosphere. This study introduces a new approach to enhancing film quality by adjusting the RF power during the sputtering process and subsequently annealing the sputtered samples. The aim was to investigate the benefits of nitrogen (N) annealing on the formation of a uniform passivation film of Tb4O7 material.
Inactivation of S. mutans dental biofilm by using Cold Atmospheric Plasma
Authors: Lim Lian Kuang , Ngoi Soo Tein , Tan Shun , Bin Shah Bana Muhammad Arif Fikri , Yap Seong Ling
Published: December 2024

S.mutans cells in oral cavity could adhere to surfaces of the teeth form the bacterial biofilm, strongly resist daily cleaning and brushing. The growth of the bacterial protected by the biofilm may lead to dental plaque formation and tooth decay.
C
old
A
tmospheric
P
lasma (CAP) generated from a capillary-guided corona discharge is investigated for the inactivation of Streptococcus mutans biofilm associated with dental caries. The plasma device was optimised to generate a 4-mm plasma plume while maintaining a temperature near to ambient. The heat generated was not susceptible to thermal damage for the biofilm, as well as the oral cavity. Through experimental evaluations, the gaseous plasma plume from the CAP with a treatment durations of up to 15 min were responsible in reducing the S. mutans biofilm. The highest removal was achieved after 15 min of CAP treatment. The results shown that a log-reduction of 3.08 of the cells in the S. mutans biofilm was killed during the treatment. The 10 min treatment demonstrated a high value of log reduction at 1.79 compared to the control well. The efficacy is found to be strongly correlated to treatment duration whereby at the minimum duration of 1 min treatment resulted a log reduction of 0.23. The outcomes of this research highlight CAP as a promising and safe approach for combating S. mutans biofilm. By offering a non-thermal alternative to traditional antimicrobial methods, CAP presents an opportunity to minimize harm to healthy tissues while effectively targeting biofilm.
A novel approach to frame reduction in robust hand gesture recognition
Authors: Balmik Archana , Sunanda  , Nandy Anup
Published: December 2024

Hand gesture recognition is becoming an increasingly integral part of our daily lives, enabling seamless communication, enhancing interaction, and revolutionizing multiple industries. To ensure a more precise and efficient system, the key aspect of hand gestures lies in detecting hand patterns and retrieving the hand gestures. However, as the volume of video data increases, extracting the essential hand patterns while excluding unnecessary frames becomes a challenge. Addressing this issue, a novel Harris Hawk Optimization K-Means frame reduction is proposed, inspired by the hunting behavior of Harris Hawks in nature. This proposed approach combines the Harris Hawk Optimization algorithm with the K-Means clustering method. The algorithm simulates the hunting behavior of Harris Hawks and utilizes Euclidean distance as a fitness function to determine the optimal frames. Subsequently, the K-Means clustering method is employed to group similar frames together based on these optimal selections. An average frame is generated and aggregated for each cluster to form a reduced set of frames. These reduced frames are then classified using the modified Mobilenet V2 model, outperforming other state-of-the-art techniques by achieving an exceptional accuracy rate of 99.93%. The experiment results lay the groundwork for incorporating the novel framework of hand gesture recognition into a range of applications, including sign language interpretation, human-computer interaction, and virtual reality systems.
Corrections to scaling in the 2D φ4 model:Monte Carlo results and some related problems
Authors: Kaupuzs Jevgenijs , Melnik Roderick
Published: December 2024

Monte Carlo (MC) simulations have been performed to refine the estimation of the correction-to-scaling exponent ω in the 2D φ4 model, which belongs to one of the most fundamental universality classes. If corrections have the form ∝L-ω, then we find ω=1.546(30) and ω=1.509(14) as the best estimates. These are obtained from the finite-size scaling of the susceptibility data in the range of linear lattice sizes L∈[128,2048] at the critical value of the Binder cumulant and from the scaling of the corresponding pseudocritical couplings within L∈[64,2048]. These values agree with several other MC estimates at the assumption of the power-law corrections and are comparable with the known results of the ε-expansion. In addition, we have tested the consistency with the scaling corrections of the form ∝L-4/3, ∝L-4/3ln L and ∝L-4/3/ln L, which might be expected from some considerations of the renormalization group and Coulomb gas model. The latter option is consistent with our MC data. Our MC results served as a basis for a critical reconsideration of some earlier theoretical conjectures and scaling assumptions. In particular, we have corrected and refined our previous analysis by grouping Feynman diagrams. The renewed analysis gives ω≈4-d-2η as some approximation for spatial dimensions d<4, or ω≈1.5 in two dimensions.
Improving Image Quality of the Solar Disk Imager (SDI) of the Lyα Solar Telescope (LST) Onboard the ASO-S Mission
Authors: Liu Hui , Li Hui , Zou Sizhong , Ji Kaifan , Jin Zhenyu , Shan Jiahui , Li Jingwei , Shi Guanglu , Huang Yu , Feng Li , Xue Jianchao , Li Qiao , Song Dechao , Li Ying
Published: December 2024

The in-flight calibration and performance of the Solar Disk Imager (SDI), which is a pivotal instrument of the Lyα Solar Telescope onboard the Advanced Space-based Solar Observatory mission, suggested a much lower spatial resolution than expected. In this paper, we developed the SDI point-spread function (PSF) and Image Bivariate Optimization Algorithm (SPIBOA) to improve the quality of SDI images. The bivariate optimization method smartly combines deep learning with optical system modeling. Despite the lack of information about the real image taken by SDI and the optical system function, this algorithm effectively estimates the PSF of the SDI imaging system directly from a large sample of observational data. We use the estimated PSF to conduct deconvolution correction to observed SDI images, and the resulting images show that the spatial resolution after correction has increased by a factor of more than three with respect to the observed ones. Meanwhile, our method also significantly reduces the inherent noise in the observed SDI images. The SPIBOA has now been successfully integrated into the routine SDI data processing, providing important support for the scientific studies based on the data. The development and application of SPIBOA also paves new ways to identify astronomical telescope systems and enhance observational image quality. Some essential factors and precautions in applying the SPIBOA method are also discussed.