bluuebunny/crossref_metadata_2025 huggingface dataset:
Overestimation of melting temperatures calculated by first-principles molecular dynamics simulations
Authors: Shirai Koun , Momida Hiroyoshi , Sato Kazunori , Hyun Sangil
Published: February 2025

Calculating the melting temperature,

T

m

, by molecular dynamics (MD) simulations is a controversial issue. Even first-principles MD (FP-MD) simulations often give large overestimations. The accuracy of the

T

m

value obtained by FP-MD simulations has been assessed by examining various solids and calculation parameters. Because the equilibria of liquids are achieved by the balance between many atom relaxation processes, adiabatic simulation—no use of thermostat—is necessary. The present simulations resolved the presence of the width

W

m

for the transition, which vanishes only at the thermodynamic limit. This brings uncertainty to the obtained

T

m

value by

W

m

. Within this uncertainty, it has been demonstrated a good agreement in

T

m

is obtained for Si and Na by a reasonable size of cells, namely, approximately 100 atoms. This implies that the contribution of surface in determining

T

m

does not constitute a universal reason for use of the solid–liquid coexistence method for bulk solids, unless too large surface energy or other factors are involved. On the other hand, typically for oxide materials, the FP-MD simulations give large overestimations for

T

m

, which are insensitive to the calculation conditions. It is highly likely that the overestimation in

T

m

is brought about by the LDA/GGA error in the electron correlation functional.
The efficient method of lattice dynamics calculation: Monte Carlo integration with importance sampling
Authors: Morita Michimasa , Shiomi Junichiro
Published: February 2025

In this study, we aimed to accelerate the thermal conductivity calculations of crystalline nanostructures using anharmonic lattice dynamics. For this we implemented Monte Carlo (MC) integration for relaxation time calculations and achieved a dramatic acceleration of approximately two orders of magnitude. The relaxation times can be calculated by computing the scattering rates for all phonon combinations; however, in this MC integration, we instead calculated the scattering rates of a randomly sampled subset of combinations. Then, we estimated the overall scattering rate. Simple MC integration samples the scattering channels that do not contribute to the total scattering rate, leading to inefficiencies. To address this issue, we implemented an importance sampling method (ISM) for improving sampling efficiency. In this study, we compared the computational speeds of both methods and investigated the differences in accuracy by comparing the results with the exact values obtained from traditional relaxation time calculations. The comparison showed similarity between both methods in terms of speed; however, ISM was faster when the error margin was ∼5%. Furthermore, while simple MC integration risks significantly worse accuracy as the system size increases, the ISM remains relatively robust and reliable.
Tuning magnetism in Ising-type van der Waals magnet FePS3 by lithium intercalation
Authors: Upreti Dinesh , Basnet Rabindra , Sharma M M , Karki Chhetri Santosh , Acharya Gokul , Nabi Md Rafique Un , Sakon Josh , Da Bo , Mortazavi Mansour , Hu Jin
Published: February 2025

Recently, layered transition metal thiophosphate MPX
3 (M = transition metals, X = S or Se) have gained significant attention because of their rich magnetic, optical, and electronic properties. Specifically, the diverse magnetic structures and the robustness of magnetism in the two-dimensional (2D) limit have made them prominent candidates to study 2D magnetism. Numerous efforts such as substitutions and interlayer intercalations have been adopted to tune the magnetic properties of these materials, which has greatly deepened the understanding of the underlying mechanisms that govern the properties. In this work, we focus on modifying the magnetism of Ising-type antiferromagnet FePS3 using electrochemical lithium intercalation. Our work demonstrate the effectiveness of electrochemical intercalation as a controllable tool to modulating magnetism, including tuning magnetic ordering temperature and inducing low temperature spin-glass state, offering an approach for implementing this material into applications.
First-principles calculation of the stopping power of protons in hexagonal boron nitride with different stacking sequences
Authors: Zhang Bin , Ying Tao , Li Weiqi , Xing Chaoyang , Yang Song Yuan , Yang Jianqun , Li Xingji
Published: February 2025

This study employs the real-time time-dependent density functional theory method to conduct an in-depth investigation of the energy dissipation mechanism of proton in hexagonal boron nitride (h-BN) materials. By calculating the stopping power to quantify the energy dissipation of proton, we find that the energy dissipation in h-BN is primarily dependent on electron excitation, with relatively minor nuclear energy loss. Furthermore, we analyze the micro-dynamic behavior of radiation particles in detail by tracking the forces exerted on proton and the charge transfer process. Finally, by simulating the energy transfer of proton through bilayer h-BN under different stacking sequences, we explore the influence of stacking structures on stopping power. The results indicate that asymmetric stacking structures exhibit slightly higher stopping power, which may become a potential stacking configuration for radiation protection. The findings of this study not only provide a new perspective for understanding the radiation response of h-BN materials but also lay an important theoretical foundation for the long-term radiation protection design of h-BN materials.
Self-powered wireless sensing technologies based on triboelectric nanogenerator
Authors: Si Jiawei , Yang Jin , Zhu Zhaofeng , Li Zhukun , Lai Haiyang , Han Lei
Published: February 2025

With the rapid development of the Internet of Things, sustainable energy supply and wireless transmission of distributed wireless sensor nodes have become a challenge. In recent years, self-powered wireless sensing technologies (SWSTs) combining triboelectric nanogenerators (TENG) and wireless solutions have been proposed to address the issues of energy harvesting and wireless transmission. This review systematically summarizes the research advances in SWSTs based on TENG, and compares the advantages and disadvantages of different technologies. In addition, challenges and expectations for future TENG-based SWSTs are discussed as well.
Low-temperature growth of wafer-scale amorphous boron nitride films with low-dielectric-constant and controllable thicknesses
Authors: Zheng Hang , Wan Zihao , Tang Wenna , Huang Xianlei , Zhou Zhenjia , Liu Weilin , Wang Chao , Yuan Guowen , Gao Libo
Published: February 2025

Amorphous boron nitride (aBN) films, with extremely low relative dielectric constant (κ) and chemical inertness, are excellent insulation and packaging materials for electronic device interconnection. It is of great significance to prepare the low-κ aBN films with controllable thickness, but there are still some limitations to achieve the goal. In this study, we succeed in growing wafer-scale aBN films with specific thicknesses from 1.2 to 4.0 nm by varying the growth time and temperature. The thickness of the films increases linearly with growth time and the crystallinity of BN films is precisely controlled by the growth temperature. The preferred temperature for aBN films ranges from 200 °C to 400 °C. Raman spectroscopy, x-ray photoelectron spectroscopy and transmission electron microscope all confirm the amorphous feature. These films are wafer-scale uniformity and have an ultra-flat surface, with excellent thermal stability and corrosion resistance. Particularly, the growth temperature affects the κ value and breakdown voltage of aBN films. The aBN films grown at 200 °C have the lowest κ value of 1.66 at 100 kHz, along with the breakdown field strength of 5.5 MV cm−1. We believe that wafer-level aBN films with various thicknesses can bring new opportunities for the development and application of nanoscale electrical devices.
Impact of conductive-filler content on the static sensing performance of spray-coated flexible strain sensors for steel-bridge strain monitoring
Authors: Chen Jun , Cui Chuang , Zhang Qing-hua
Published: February 2025

Flexible strain sensors fabricated using spray coating enable efficient and reliable strain monitoring of steel bridges. This study aimed to develop a flexible strain sensor with an extremely low detection limit, high linearity, and high sensitivity. The sensing layer materials were prepared by simply mixing silver-coated copper powder particles and water-based acrylic emulsion. Commercial moisture-proof insulating paint for printed circuit boards was used as the insulating layer, and modified polyurethane resin was used as the protective layer. Sensors were fabricated using the spray coating process, and the influence of the conductive-filler content on their static sensing performance was investigated. The results showed that the sensor exhibited the highest sensitivity near the percolation threshold, with a gauge factor of 272.54 and minimum strain detection limit of 0.000 98% but suffered from high resistance relaxation and hysteresis. At higher conductive-filler contents, the resistance relaxation and hysteresis decreased; however, the sensitivity decreased, and the minimum detection limit of strain increased. The linear correlation coefficient of the sensor first increased and then decreased with increasing filler content; however, all values were above 0.940. A comparison of the conductivity and sensing performance revealed that the performance changes were significant near the percolation threshold and stabilized away from it, whereas the linearity coincided with the conductivity changes. This indicated that the sensor performance was closely related to the initial conductive network state of the sensing layer.
Magnetorheology and sedimentation characteristics of carbonyl iron suspension in polyalphaolefin with a

γ

-Fe2O3 hard magnetic nanoparticle additive
Authors: Park ChaeWon , Wang Shizhao , Jin Hyoung-Joon , Lee Jin-Kyun , Choi Hyoung Jin
Published: February 2025

The use of micron-sized soft magnetic carbonyl iron (CI) particles in magnetorheological (MR) fluids is often limited by the sedimentation that occurs due to the density difference between these particles and the carrier fluid. To alleviate this problem, in this study hard magnetic

γ

-Fe2O3 nanoparticles (2 wt%) were introduced as an additive and polyalphaolefin (PAO) as a carrier fluid to prepare a CI (80 wt%) based MR fluid. Under a magnetic field of 343 kA m−1, the dynamic yield stress for the MR fluid containing γ-Fe2O3 was approximately 62.2 kPa, while the MR fluid containing pure CI was lower at 54.2 kPa. In addition, the MR fluid containing both

γ

-Fe2O3 and PAO-5 showed 3% less sedimentation than the sample without

γ

-Fe2O3. The sedimentation observed for the MR fluid containing PAO-5 was approximately 24% less than that of the MR fluid using 100 cSt silicone oil as the carrier, and explained based on the interaction energy

 

between the particles and the carrier fluid. Our finding indicates that the γ-Fe2O3 additive system with PAO as the carrier fluid significantly improved both the MR characteristics with higher yield stress and the dispersion stability of the CI-based MR fluid.
Nonlinear compensation of stretchable strain sensors with application to proprioceptive sensing of soft robotic arm
Authors: Naik Vedant , Fairchild Preston , Tan Xiaobo
Published: February 2025

With advances in materials and manufacturing techniques, recent years have seen a number of conductive composite materials that exhibit pronounced strain-dependent electrical resistivity, allowing them to be used for embedded, cost-effective strain sensing in various applications. The strain-resistivity relationship of these materials, however, is often highly nonlinear and dynamic, posing challenges for effective use of such strain sensors. In this paper, a computationally efficient scheme is proposed for compensating the nonlinear, dynamic strain-resistance behavior of a soft conductive rubber using a time delay neural network. The accuracy and feasibility of the technique is evaluated with a soft robotic arm incorporating three strain sensors for proprioception. Experimental results show that the sensing scheme is able to predict both the tip position and the shape of the robotic manipulator, achieving an average tip positional error of less than 4% relative to the total length of the manipulator.
Hierarchical molybdenum disulfide microspheres: a sustainable and highly efficient adsorbent for removal of methylene blue and congo red from wastewater
Authors: Chathambally Vijina , Damodaran Shima P
Published: February 2025

This study reports the facile and cost-effective hydrothermal synthesis of hierarchical molybdenum disulfide (MoS2) microspheres having superior adsorption capacity for organic dye pollutants. The structural and morphological characteristics of as-synthesized MoS2 microspheres were analyzed by using XRD, SEM, TEM and Raman spectroscopy techniques. Morphological studies revealed that the individual microspheres were composed of many interconnected MoS2 nanosheets, providing them a huge surface. On account of this unique feature, the MoS2 microspheres developed in the present study exhibited enhanced adsorption capacity for cationic dye methylene blue (MB) and anionic dye congo red (CR). The effects of pH, adsorbent dosage, initial dye concentration, and contact time on the adsorption of MB and CR were investigated in detail in the present study. A maximum adsorption capacity of 681.10 and 978.43 mg g−1 were attained for MB and CR respectively which were exceptionally high in comparison with most of the previously reported MoS2-based adsorbents. The adsorption of MB and CR on MoS2 microspheres followed the pseudo-second-order kinetics model and the Freundlich isotherm model. The mechanism of adsorption was explored using intraparticle diffusion (IPD) and Richenberg models. The results showed that the adsorption of MB and CR onto MoS2 microspheres is a multi-step process and IPD has a major contribution in the case of CR adsorption. The MoS2 microspheres retained more than 90% removal efficiency even after five recycle runs. As the developed adsorbent consists of pristine MoS2, there are vast scopes for its functionalization/modification to improve its adsorption ability thereby making it an excellent platform for novel research in the field of environmental remediation.
Planar, broadband, and tunable hot-electron photodetection with chromium-involved Tamm plasmons
Authors: Li Yaoyao , Cui Weihao , Wang Yongmei , Zhou Qingjia , Hu Junhui , Shao Weijia
Published: February 2025

Planar hot-electron photodetectors (HE PDs) often operate at specified working wavelengths at which devices exhibit high optical absorption efficiencies. Recently, several planar HE PDs with strong optical absorptions across broad wavelength ranges have been demonstrated. However, the studies about spectral tunability of broadband HE PDs remain scarce and planar hot-electron photodetection with customized spectral linewidths are still absent. Herein, we propose a Tamm plasmon (TP) design of planar, broadband, and tunable HE PDs that have a thin Cr film on a distributed Bragg reflector. Optical investigations show that the thickness of dielectric layer adjacent to Cr layer is a critical factor in determining TP-induced optical responses, including prominent anti-reflection characteristic and broadband strong absorption in the Cr layer. Subsequent electrical analysis verify that device electrical spectra are strongly related to the thickness of critical dielectric layer that have great effects on spectral properties about electronic processes. Comparison studies between the designed Cr-involved device and referenced Au-involved device highlight the superiority of the designed device in high average responsivity and variable broad linewidth.
Unveiling magnetic states in nanotubes: insights from remanent ferromagnetic resonance spectroscopy
Authors: Kumar Abhishek , Kalouni Chirag , Posti Raghvendra , Malik Vivek K , Tiwari Dhananjay , Roy Debangsu
Published: February 2025

Magnetic nanotubes have garnered immense attention for their potential in high-density magnetic memory, owing to their stable flux closure configuration and fast, reproducible reversal processes. However, characterizing their magnetic configuration through straightforward methodologies remains a challenge in both scope and detail. Here, we elucidate the magnetic state details using Remanence Field Ferromagnetic Resonance Spectroscopy (RFMR) for arrays of electrodeposited nanotubes. Micromagnetic simulations revealed distinct spin configurations while coming from saturation, including the edge vortex, onion, uniform and curling states, with chirality variations depending on the preparation field direction. We identified individual spin configurations, as depicted in our micromagnetic simulations, through careful measurements of the RFMR spectra starting from both positive and negative saturation. The Observations revealed opposite RFMR spectra, indicating opposite magnetic spin configurations after removing the positive and negative saturating fields when the magnetic field was applied along

(
θ

H

=

0

o

)

and perpendicular

(
θ

H

=

90

o

)

to the nanotube axis. We observed a mixture of the non-uniform curling states with the end vortex state (onion-like curling state) at the end of the nanotubes for the

θ

H

=

0

o

(

90

o

)

and uniform magnetization states in the middle of the nanotubes for the

θ

H

=

0

o

configuration. Dynamic measurements in presence of the bias field, coupled with RFMR spectra analysis, provided insights into the evolution of individual modes. Additionally, our FMR analysis indicates nucleation within the edge vortex state, which was further corroborated by micromagnetic analysis and substantiated with First Order Reversal Curve (FORC) measurements.
Van der Waals interactions in linear chains with long-range correlated disorder
Authors: Mualem Yuval , Poddubny Alexander N
Published: February 2025

We present a theoretical study of van der Waals interaction forces in disordered linear molecule chains. We demonstrate that the interaction energy strongly and nonmonotonously depends on the disorder correlation length. Semianalytical expressions for the interaction energy are obtained.
Tailoring quantum wells in AlGaInP laser diodes for superior optical performance
Authors: Anum  , Usman Muhammad , Habib Usman
Published: February 2025

This work employed composition-graded quantum wells (QWs) to increase the performance of red laser diodes (LDs) based on Aluminum gallium indium phosphide (AlGaInP). Two LDs, one with conventional QWs and other with composition-graded QWs, were studied numerically. The findings showed that the LD with composition-graded QWs significantly improved the device performance such as enhanced carrier concentration in the active region, decreased carrier leakage, improved carrier injection efficiency, and a higher rate of stimulated recombination rate. According to the results of the simulation, grading the QWs enhanced the slope efficiency to 0.80 W A−1 and successfully reduced the threshold current to 300 mA. This enhanced performance, compared to conventional LDs, demonstrates the promising impact of our employed composition grading.
Quantum neural network classifier with differential privacy
Authors: Li Guodong , Yu Fangce , Wang Qingle , Liu Lin , Mao Ying , Cheng Long
Published: February 2025

Quantum neural networks (QNN) hold the potential for quantum advantages but are confronted with privacy leakage risks that could undermine users’ benefits. To address this issue, we propose an enhanced QNN model integrated with differential privacy. After converting classical data into quantum states using encoding circuit, we apply data re-uploading technology to embed the encoding circuit multiple times into the overall circuit. The classification outcomes are derived by measuring the final quantum state. During the optimization process of QNN, we introduce Gaussian noise into the gradient of the loss function to ensure differential privacy. Our theoretical analysis demonstrates that in differential privacy settings, the model effectively protects privacy while demonstrating good performance. Our experimental analysis demonstrates that on four standard datasets, our model achieves the same accuracy as classical neural network (NN) while utilizing only 22% of the parameters of NN, and exhibiting lower performance loss compared to other QNN.
Detection of electron temperature anisotropy by an x-ray crystal spectrometer in the Large Helical device
Authors: Kawate Tomoko , Goto Motoshi , Oishi Tetsutarou , Kawamoto Yasuko , Yamada Ichihiro , Funaba Hisamichi , Takahashi Hiromi
Published: February 2025

We examine Ar XVI spectra measured by an x-ray crystal spectrometer to estimate electron temperature anisotropy in high-temperature electron cyclotron heated plasmas in the Large Helical Device (LHD). We calculate the atomic structure and electron impact excitation cross section between magnetic sublevels of Ar XVI. By assuming a bi-Maxwellian electron distribution function and considering the mount parameters of the x-ray spectrometer in LHD, we model the expected intensity ratio q/r as a function of T

e⊥B
and T

e∣∣B
, where ⊥B and ∣∣B denote perpendicular and parallel components to the magnetic axis of toroidal plasma, respectively. The calculation results show that the intensity ratio of q and r, which are formed by inner-shell excitation from the ground state of Ar15+, is sensitive to electron temperature anisotropy. We apply the calculation results to the LHD experiments. The ratio of q/r changes with variations in electron density and collision frequency. In the core and low ν

e
region, T

e⊥B
is predominant, and the electron temperature becomes isotropic above ν

e
 > 104 Hz. By combining electron temperature measurements from Thomson scattering and radial profile of Ar15+ ions estimated using the extreme ultraviolet spectrometer, local values of T

e⊥B
/T

e∣∣B
are quantitatively estimated using the q/r ratio. The derived T

e⊥B
/T

e∣∣B
is compared with collision frequency, radial electric field, and effective helical ripple, and the experimental results are explained qualitatively.
Realizing topological quantum walks on NISQ digital quantum computer
Authors: Giri Mrinal Kanti , Mandal Sudhindu Bikash
Published: February 2025

We study the quantum walk on the off-diagonal Aubry-André-Harper (AAH) lattice with periodic modulation using a digital quantum computer. We investigate various initial states at the single-particle level, considering different hopping modulation strengths and phase factors. Initiating the quantum walk with a particle at the lattice edge reveals the robustness of the edge state, attributed to the topological nature of the AAH model, and displays the influence of the phase factor on this edge state. On the other hand, when the quantum walk begins with a particle in the lattice bulk, we observe a repulsion of the bulk walker from the edge, especially under strong hopping modulation. Furthermore, we extend our investigation to the quantum walk of two particles with nearest-neighbour (NN) interaction. We show the repulsion effect in the quantum walk when two walkers originate from the edge and bulk of the lattice due to the interaction. Additionally, when two particles are positioned at nearest-neighbor sites with strong hopping modulation, they unexpectedly form a local bound state at very small interaction strength, highlighting the unique interplay between hopping modulation and interaction in our quantum walk setup. We analyze these phenomena by examining physical quantities such as density evolution, two-particle correlation, and participation entropy, and discuss their potential applications in quantum technologies.
Enhanced thermal stability and mechanical properties of polypropylene matrices reinforced with SiO2 nanoparticles
Authors: Wasel M A , Wassel Ahmed R , Sewid F A , El-Tonsy M M , El-Henawey M I
Published: February 2025

The current study focuses on incorporating SiO2 nano-fillers into a polypropylene matrix to enhance and regulate the coefficient of thermal expansion (CTE) while simultaneously improving physical, mechanical, and thermal properties. This approach involves adding small quantities of SiO2 filler to occupy vacant spaces between polymer chains, reducing the CTE of the polymer without affecting its structure. Silicon dioxide nanoparticles (SiO2-NPs) were added to a polypropylene (PP) matrix at various concentrations (1%wt, 2%wt, 3%wt, 4%wt, 5%wt, 6%wt). The prepared samples underwent characterization through techniques including x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC), along with analysis of the coefficient of thermal expansion, Young’s modulus, and tensile strength. Observations revealed that the inclusion of small quantities of filler significantly enhances the mechanical and thermal properties of PP, particularly at 3%wt of SiO2, which exhibited the lowest CTE value. This methodology can be regarded as an effective approach for controlling the CTE value of polymers, potentially opening avenues for various industrial applications of these materials.
Exact solutions to the resonant nonlinear Schrödinger equation with time-dependent coefficients under dual-power law nonlinearity
Authors: Wang Zilin , Gao Ben
Published: February 2025

In this paper, the resonant nonlinear Schrödinger equation with time-dependent coefficients which appears in the research process of Madelung fluid is probed by means of two different methods. As an outcome, dozens of distinct types of complex exact solutions are built in the condition of taking dual-power law nonlinearity into account. More specifically, a range of complex solitary, soliton as well as elliptic wave solutions are offered in terms of the unified method, and a series of hyperbolic, triangular, Jacobi elliptic doubly periodic, rational as well as exponential type solutions are given in the light of the improved modified extended tanh-function method. Moreover, the dual-power law nonlinearity, it should be noted, can degenerate to other popular nonlinearity forms including the kerr, power, parabolic law nonlinearities and quadratic-cubic nonlinearity with specific values of concerned parameters, and we also consider these peculiar circumstances in the solving process. Finally, we draw 2D, 3D and contour images for distinct types of solutions that we acquired to simplify the physical interpretation.
Novel star fractal MIMO antenna integrated with a unique parasitic decoupler for enhanced 5 G/IoT/UWB communication performance
Authors: Sohi Arashpreet K
Published: February 2025

This study focuses on the development, simulation, and experimental analysis of a two-port, fractal-inspired UWB antenna array for optimal deployment in 5 G/IoT/UWB systems. The array is structured 1.57 mm thick, dielectric FR4 material, encompassing a 38 × 66 mm2 area. The design includes two offset-fed pentagonal radiating patches defective with a 2nd iterative novel star-fractal pattern on its upper surface, which optimizes the array’s radiative properties and triggers a wide operating range of 3–14.6 GHz with an impedance bandwidth ratio of 3.87:1. The application of unique star-fractal design contributes to 54.33% shrinkage of patch area in contrast to the typical pentagonal patch. The rear dielectric layer features a reduced ground plane embedded with novel parasitic and stub-loading decoupling structures (placed centrally) to significantly suppress the cross-coupling between the array units and minimize mismatch losses. Multiple diversity parameters are reviewed and are found to comply with their defined thresholds, demonstrating a favorable match between simulation and experimental findings. The array design effectively addresses the rising demand for compact solutions tailored for handheld devices, thus facilitating real-time operations in 5 G/IoT frameworks.
Data2Summ: review on enhancing summarization with transformers and attention models for speech and text compression
Authors: Krishna Dasari Siva , Srikanth Panigrahi , Rao Routhu Srinivasa , Holla M Raviraja
Published: February 2025

Today, nearly 120 zettabytes of data are generated daily, with a significant portion coming from speech and text. Digesting such vast amounts of data is a daunting task for the average person. To simplify this challenge, various speech and text summarization techniques are being developed. Summarization is a crucial task that aims to condense key information from text while preserving its overall meaning. This work focuses on developing Data2Summ, an efficient approach for summarizing speech and text by leveraging transformers and advanced attention models. These models capture intricate contextual relationships between words, enabling a nuanced understanding of the input data. The methodology incorporates various models, such as BERT, Pegasus, Llama-2, RoBert2Robert, T5, and DistilBERT, which harness the power of transformers that have demonstrated exceptional performance in various natural language processing tasks. Additionally, we experiment with a modified version of DistilBERT, which shows improved performance compared to other transformers. Evaluation includes benchmarking against existing summarization techniques and assessing the quality, coherence, and informativeness of the generated summaries using ROUGE score.
Spectral analysis for a class of weighted non-p.c.f. Sierpiński-like networks
Authors: Zhu Zhiyong , Dong Enmei
Published: February 2025

Much information about the structural properties and relevant dynamical aspects of a network can be encoded by the eigenvalues of its normalized Laplacian matrix, particularly those related to random walks. This paper presents a study of the normalized Laplacian spectra and their applications for a class of weighted non-p.c.f. Sierpiński-like networks with a non-uniformly bounded distribution of vertex degrees. Utilizing the spectral decimation technique alongside a theoretical matrix analysis supported by symbolic and numerical computations, we analytically obtain all the eigenvalues, as well as multiplicities. We then apply the derived spectra to derive the analytical expressions for Kemeny’s constant and the number of spanning trees in the networks under consideration, and calculate the asymptotic growth constant characterizing the network, demonstrating the effectiveness of our normalized Laplacian spectra computation.
A comprehensive numerical simulation analysis of back surface passivated CIGS solar cells for efficiency enhancement
Authors: Kumar Alok , Giripunje Sushama M , Patel Alok Kumar , Gohri Shivani
Published: February 2025

Thin film solar cells are economical and simple to produce. This study seeks to comprehensively analyze ways to improve the efficiency and minimise the cost per watt of CIGS/SWCNT bulk heterojunction solar cells. The device performance is enhanced by lowering the defect density of single-walled carbon nanotubes (SWCNTs) and minimizing back surface recombination velocity through the back surface field mechanism. To maintain the realistic condition throughout the simulation authors, consider the series (Rs) and shunt (Rsh) resistances of 0.5 and 103 ohm cm2 respectively. The optoelectronic output parameters VOC, JSC, FF, and efficiency (η) of the cells are extensively studied using the SCAPS-1D simulation tool with respect to variations in thickness, acceptor density, radiative recombination coefficient, parasitic resistance, work function, temperature, and defect density. The novel solar cell device structure Ni/SWCNT/CIGS/WS2/ZnO/Al exhibits a photoconversion efficiency of 27.73% followed by VOC of 0.80 V, FF of 80.38%, and JSC of 42.59 mA cm−2 at CIGS thickness of 400 nm. Mott Schottky Plot analysis was carried out at a frequency of 1 MHz to find the built-in potential (0.67 V) of the proposed solar cell. This simulation study could help manufacturing companies enhance the profitability of CIGS solar cell production.
Near-infrared supercontinuum source from an ultrafast erbium-doped fiber laser based on polyacrylonitrile absorber
Authors: Ahmad Aeriyn D , Mokhtar Norrima , Dimyati Kaharudin , Apsari Retna , Harun Sulaiman W
Published: February 2025

Our study explores the application of Polyacrylonitrile (PAN), a soluble organic material valued for its thermal stability, UV resistance, high strength, and chemical inertness, in the field of supercontinuum generation (SCG). Specifically, we investigate its use as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) for ultrafast laser generation. The PAN SA is fabricated by embedding PAN compounds into a Polyvinyl Alcohol (PVA) host polymer. Integration of the PAN SA into the laser cavity enables stable mode-locking operation, generating a conventional soliton pulse train centred at 1567.0 nm wavelength. Mode-locking is maintained over a pump power range of 87.2 to 254.1 mW at a repetition rate of 1.78 MHz, producing pulses with a duration of 920 fs and a maximum peak power of 0.67 kW. Upon amplification with an Erbium-doped fiber amplifier, the average output power reaches 24 dBm, albeit with a slight increase in pulse duration to 1 ps. The amplified soliton pulse is then coupled into a 100 m long highly nonlinear photonic crystal fiber (HN-PCF) with zero dispersion at 1550 nm, resulting in the realization of near infrared SCG. The supercontinuum spans from 1375 nm to at least 2000 nm, achieving spectral power exceeding −35 dBm. To our knowledge, this work represents the first demonstration of SCG by utilizing PAN-based femtosecond pulses to pump a nonlinear fiber.
Metal ferrite nanocomposite treatment reduced oxidative stress to improve the growth dynamics of Cucumis sativus in hydroponics
Authors: Parbhakar Mannat , Guleria Praveen , Kumar Vineet
Published: February 2025

Green synthesized nanoparticles have various applications but their use for improving plant productivity and agricultural sustainability recommends their usage as nano-fertilisers. In this context, the present study reports the positive influence of hydroponically exposed green synthesized Tri-metal ferrite TiO2-Al2O3-ZnFe2O4 nanocomposites (TMFN) on Cucumis sativus (cucumber). Cucumber is rich in polyphenols and an important part of the human diet because of its water-rich and low-calorie nature. A considerable increase in the length of shoot-roots, relative water content, and chlorophyll level of cucumber was observed on TMFN exposure. An increase of 25–82 and 94–220% in carbohydrate and protein levels on TMFN treatment was observed. Likewise, the phenols, flavonoids, and free radical scavenging potential of the plants were increased by 22–88, 64–211, and 4–18%, respectively, on TMFN exposure. As a result, there was an observable decrease of 62–86 and 14–68% in the oxidative stress indicators, MDA and H2O2, respectively. A simultaneous and significant increase in the inorganic nitrate, nitrite content, nitrate reductase, and glutamate synthetase activity was evident. However, ammonia content and glutamate dehydrogenase activity decreased significantly by 27–82 and 31–85%, respectively. Overall, the TMFN induced significant morphological and biochemical changes in cucumber indicated their probable role as potential plant growth promoters. However further research is required for understanding the molecular and genetic aspects of the effects of green synthesised TMFN on other plants as well as crops grown hydroponically.
Restore axonal conductance in a locally demyelinated axon with electromagnetic stimulation
Authors: Ye Hui , Chen Yanan , Chen Ji , Hendee Jenna
Published: February 2025

Objective. Axonal demyelination leads to failure of axonal conduction. Current research on demyelination focuses on the promotion of remyelination. Electromagnetic stimulation is widely used to promote neural activity. We hypothesized that electromagnetic stimulation of the demyelinated area, by providing excitation to the nodes of Ranvier, could rescue locally demyelinated axons from conductance failure. Approach. We built a multi-compartment NEURON model of a myelinated axon under electromagnetic stimulation. We simulated the action potential (AP) propagation and observed conductance failure when local demyelination occurred. Conductance failure was due to current leakage and a lack of activation of the nodes in the demyelinated region. To investigate the effects of electromagnetic stimulation on locally demyelinated axons, we positioned a miniature coil next to the affected area to activate nodes in the demyelinated region. Main results. Subthreshold microcoil stimulation caused depolarization of node membranes. This depolarization, in combination with membrane depolarization induced by the invading AP, resulted in sufficient activation of nodes in the demyelinated region and restoration of axonal conductance. Efficacy of restoration was dependent on the amplitude and frequency of the stimuli, and the location of the microcoil relative to the targeted nodes. The restored axonal conductance was due to the enhanced Na+ current and reduced K+ current in the nodes, rather than a reduction in leakage current in the demyelinated region. Finally, we found that microcoil stimulation had no effect on axonal conductance in healthy, myelinated axons. Significance. Activation of nodes in the demyelinated region using electromagnetic stimulation provides an alternative treatment strategy to restore axonal function under local demyelination conditions. Results provide insights to the development of microcoil technology for the treatment of focal segmental demyelination cases, such as neuropraxia, spinal cord injury, and auditory nerve demyelination.
Structural Realism and the underdetermination of the physical meaning
Authors: Stoica Ovidiu Cristinel
Published: February 2025

I point out an underdetermination of physics, in particular of Quantum Mechanics: that of the relation between the operators and their physical meaning. The set of operators for which we attribute physical meaning is, from relational, structural, and dynamical points of view, indistinguishable from any set of operators obtained from the former by a unitary transformation that commutes with the Hamiltonian. The same is true for the structures inhabiting the world, in particular there are structures isomorphic to the structure of an observer, but they would attribute the meaning of position and other physical meanings to different operators. In particular, space itself is underdetermined from the structure of the theory. Different structures that are isomorphic to an observer would call “position” different observables, and consequently would call “space” different structures. I show that they are highly non-unique. A solution would be that all possible assignments of physical meaning to the operators allowed by the symmetries of the formalism are equally valid. But this leads to a problem: there would be no correlation between the content of the mind of an observer about the external world, and the actual properties of the external world. This has unexpected consequences: it refutes structural realism, and it shows that, in addition to the structure, the substance underlying the structures matters for consciousness to exist.
Design, development and testing of IF section for FMCW reflectometry diagnostics for tokamaks
Authors: Chaudhari Vishnu , Buch JJU , Mathur Rohit , Pathak Surya K.
Published: February 2025

Reflectometry diagnostics is essential for determining
plasma position, density, and density fluctuations to characterize
tokamak plasmas. An Ultra-fast Frequency Modulated Continuous Wave
reflectometry system for measuring time evolution of density
profiles is operational on ADITYA-U. This paper discusses the
development of an in-house IF section, signal acquisition and
processing has already been reported separately. Initially, a
modular design of the IF section was implemented. However, due to
the higher cost and bulkiness of the modular design, it was replaced
by IF section card developed in-house to achieve a compact and
cost-effective solution. This paper details the circuit simulations,
printed circuit board layout, design, and testing of the developed
IF electronics. Both modular and card based IF sections were used
and were found to be in excellent agreement with expected values of
beat frequency. Specifically, modular IF design achieves a 2.5%
error, and the card-based IF design measures with a 2% error. In
addition to having a lower error compared to the modular IF design,
the card-based design also offers a lower cost in a more robust and
compact form factor.
A guide to eusocial insect faulted agent resilience and its engineering applications
Authors: Hand James , Watson Bryan
Published: February 2025

Resilience is a vital aspect of modern systems, especially in multi-agent systems, where faulted agents (agents who do not behave properly) can compromise system performance. In response to this need for resilience, we turn to biological inspiration. Eusocial insects are a subset of insects that have caste-based labor distribution and cooperative brood care. These insects face analogous challenges in maintaining and improving resilience to external threats, making them prime examples to find unique biological solutions to resilience problems. Thus, the central question of this work is: How can eusocial insect behavior be used to inspire new approaches to prevent or limit faulted agents from impacting the performance of multi-agent systems? Engineers, however, do not always have the necessary biological expertise to identify behaviors to mimic. This article seeks to fill the following identified gap in current research and resources: There is need to study the impact of biologically inspired behaviors on faulted agent resilience, but engineers may struggle to identify sources in the biological literature to translate into engineering applications. To address this question and the identified gap, we provide a guide identifying a large range of insect resilience behaviors and examples of possible implementation of these behaviors. This guide is a functional decomposition examining how eusocial insects prevent disease propagation that engineers can transfer to their systems when seeking to mitigate faulted agents. The presented functional decomposition is made of 148 identified functions across 7 levels, organized into 5 primary categories. This provides a guide for engineers to use when looking for sources of inspiration to improve system resilience. Additional discussion is also provided to offer potential implementations of these 148 functions, so as to encourage further work and usage of this work.
Projections of climate change and its impacts based on CMIP6 models—calling attention to quantifying and constraining uncertainty
Authors: Zhang Qin , Cheng Shujie , Liu Lina , Zhang Liping , Xu Jijun , She Dunxian , Yuan Zhe
Published: February 2025

Accurately projecting climate change and its impact is crucial for quantifying the risk of extreme events and developing effective adaptation strategies. However, future projections exhibit substantial uncertainties among Earth system models (ESMs). Notably, the latest phase of the Coupled Model Intercomparison Project includes some ‘hot’ ESMs with high climate sensitivity that exceed the likely range inferred from multiple lines of evidence, leading to a broader uncertainty range compared to previous CMIP phases. Although various uncertainty quantification and constraint methods have been proposed, they are not yet widely adopted. The approach of using an equal-weighted ensemble average for projections remains prevalent. Here we examine commonly used uncertainty quantification methods and constraint projection methods, describing their characteristics. Subsequently, taking extreme precipitation as a case, we constrain the range of projection uncertainty employing two weighing constraint methods and two emergent constraint methods. The results demonstrate that all methods effectively reduce the uncertainty in extreme precipitation projections. Specifically, the comprehensive constraints reduce the projection uncertainty by 26%–31% at the long-term future (2081–2100) under different scenarios. Therefore, we strongly recommend that attention should be paid to quantifying and constraining uncertainty when undertaking future projections of climate change and its impacts.
Attribution of historical extreme heat events in different climate zones of China
Authors: Zhang Yuxia , Sun Ying
Published: February 2025

China has a vast territory with diverse climates, including the arid, semi-arid, semi-humid and humid regions. Previous studies on extreme heat event attribution mainly focus on individual events in a specific region, with less attention paid to comparisons between historical events in different climate zones. Here, we use the number, seasonal length and intensity of hot days with daily maximum temperature exceeding 35 °C, to investigate human influence on extreme heat events in early and recent periods. It is clear that all three heat indicators have shown obvious increase across China since the early 1960s, with a rapid rise in recent years and the hottest event occurring in 2022. The Coupled Model Intercomparison Project Phase 6 models generally capture the temporal evolution of these indicators, but some biases exist. We utilize an annual cycle-based method to correct the model biases in climate state and then use the adjusted model results to conduct event attribution in different historical periods. We find that human influence has greatly increased the probability of recent events across all regions, while having no impact on early historical events. For the hottest 2022 event, the risk ratios for seasonal length of hot days in a few regions could not be estimated due to zero probability in the natural world, indicating that such events would not happen without human influence. In different climate zones, the risk ratios for all indicators in arid northwestern China exceed those in other regions when using consistent observational thresholds, indicating a greater response of extreme heat to anthropogenic forcing in this area. For the same event, attribution results of different indicators yield varying risk ratios, highlighting the importance of considering multiple indicators in event attribution. Additionally, model performance notably affects attribution results; without bias correction, human influence may be incorrectly estimated.
Singletons in supersymmetric field theories and in supergravity
Authors: Samtleben Henning , Sezgin Ergin
Published: February 2025

We consider N = 1 supergravity coupled to a Wess–Zumino multiplet with a potential such that the resulting AdS energies saturate the unitarity and Breitenlohner–Freedman bounds, respectively. Imposing regular boundary conditions that preserve supersymmetry and support finite norms, the spectrum forms an

O
S
p
(
1
,
4
)

supermultiplet in which the singleton representation is absent. We study the case in which this boundary condition is relaxed such that the singleton and its superpartners survive and form an indecomposable representation of

O
S
p
(
1
,
4
)

. Focusing on the global limit of the model, we carry out its holographic renormalization, in which a singletonic action makes appearance in the boundary action.

Contribution to Stanley Deser memorial volume ‘Gravity, Strings and Beyond’