bluuebunny/crossref_metadata_2025 huggingface dataset:
The acquisition of grammatical gender in child and adult heritage speakers of Spanish
Authors: Cuza Alejandro , Sánchez Liliana
Published: December 2024

Previous work on the acquisition of grammatical gender in child and adult heritage speakers of
Spanish has found significant mismatches in gender agreement stemming from overgeneralization of the masculine form to
contexts in which the feminine is required. It has been argued that these divergences stem from various sources
including incomplete acquisition during childhood (e.g. Montrul & Potowski,
2007; Montrul, Foote, & Perpiñan, 2008), form/meaning
mapping issues (e.g. Alarcón, 2011) or reconfiguration of gender features
(e.g. Cuza & Pérez-Tattam, 2016; Scontras, Polinsky, & Fuchs, 2018). The goal of the present chapter is to examine this previous work
on grammatical gender and the extent to which it can shed light on more recent proposals on heritage language
theorizing. We follow the Bilingual Alignment Approach (Sánchez, 2019) to
argue that the divergences heritage speakers show can be better accounted for in relation to crosslinguistic influence
at the level of bilingual alignments, linguistic proficiency and specific patterns of language exposure and usage.
Phonology and sentential semantics
Authors: Grimm Angela , Schulz Petra
Published: December 2024

The aim of this study is to investigate phonology (via consonant clusters) and sentential semantics (via exhaustivity in wh-questions) regarding their potential to characterize SLI in the context of bilingual acquisition. Using the German LITMUS-QU-NWR task and the exhaustivity task, the phonological and semantic abilities of 5- to 6-year-old simultaneous-bilingual (2L1) and early second language (eL2) learners of German with SLI were compared to their typically developing peers. The results suggest that in this age group language-dependent phonological knowledge regarding consonant clusters is a marker of SLI for 2L1 and eL2 children, while language independent knowledge of consonant clusters is a marker of SLI only for eL2 children. At age 5 to 6, exhaustivity is not a marker of SLI in either bilingual group. Consistent with the notion of subtypes of SLI, individual analyses revealed considerable heterogeneity within the two SLI groups. We argue that characterization of bilingual SLI requires analyses of group and individual data, and moreover, consideration of the age at testing in relation to timing in monolingual acquisition. The COST-tasks are suitable for combining both approaches.
Grounding analytical mechanics in statics: a didactic emphasis on the principle of virtual work
Authors: Weber Pereira Rodrigo , Karam Ricardo Avelar Sotomaior , Heidemann Leonardo Albuquerque , Veit Eliane Angela
Published: December 2024

Many textbooks on analytical mechanics introduce the Lagrangian formalism with D'Alembert's or Hamilton's principle. However, the validity of D'Alembert's principle is rooted in an ancient law of statics, the Principle of Virtual Work (PVW), which is rarely discussed in these texts, potentially causing difficulties. Likewise, the well-known tendency of nature to optimize physical phenomena is a straightforward consequence of the PVW, from which Hamilton's principle can also be derived. While Lagrange felt it necessary to dedicate half of his classical book to justify the validity of the PVW, today it is often regarded as a trivial intermediate step when establishing D'Alembert's principle. In this paper, following the path set by Lagrange—though in modern notation—the didactic potential of working with the PVW as an initial step before studying dynamics at the undergraduate level is explored. Beyond elucidating its conceptual richness and historical significance, several practical applications of the PVW are provided, aiming for a deeper understanding of the foundations of dynamics.
Enhanced giant magnetoresistance in Heusler alloy

(

Co
2

FeSi

/

Ag

)
N

multilayers for read sensor applications
Authors: Khamtawi R , Chureemart J , Chantrell R W , Chureemart P
Published: December 2024

We theoretically investigate the spin transport behavior of multilayer

[

Co

2

FeSi

/

Ag

]
N

structure for the application of next-generation read sensors in hard disk drive. To demonstrate the potential of the Heusler alloy-based current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) device, we employ an atomistic model coupled with a spin accumulation model including the effect of a diffuse interface. The dynamics of magnetization is observed in the atomistic model and the calculation of magnetoresistance (MR) and MR ratio of the magnetic structure can be achieved by the spin accumulation model enabling us to investigate the spin transport behavior within the structure. The MR value can be directly calculated from the gradient of spin accumulation and spin current. The effect of injected current density is first investigated. It is found that increasing the current density results in a high MR ratio. Subsequently, to achieve a high performance reader, the number of coupled layers (N) is varied up to 16 to study its effect on the MR ratio. The calculated results indicate that increasing the number of layers N gives rise to the enhancement of the resistance change and MR ratio. At the critical point N = 5, further increasing N does not affect the MR ratio, which remains relatively unchanged. Interestingly, the MR ratio is doubled for

N
>
5

compared to N = 1. Our results demonstrate the possibility of enhancing the performance of multilayer CPP-GMR devices.
Study of the spatial measurement of electron density in the EAST discharge using a multichannel terahertz solid-source interferometer
Authors: Yan Huihui , Liu Haiqing , Wang Shouxin , Wei Xuechao , Yao Yuan , Zhang Yao , Peng Ximo , Lian Hui , Li Weiming , Jie Yinxian , Jiang Jun , Tian Yaoling
Published: December 2024

A vertical single-channel 0.65 THz solid-source interferometer (SSI) has been established at Experimental Advanced Superconducting Tokamak (EAST) for real-time electron density measurements and feedback. A line array detection scheme was proposed and successfully deployed on EAST to enhance the spatial resolution of the SSI system. The scheme utilizes an AlGaN/GaN line array high electron mobility transistor detector, and three channels of line-integrated electron density signals were measured. A representative density measurement was conducted with an intermediate frequency of 850 kHz in a discharge with a current (I
p) of 400 kA and electron cyclotron resonance heating power (P
ECRH) of 1.1 MW on EAST. Additionally, the detection of density perturbations by the SSI system during plasma discharges demonstrates its capability to study small-scale spatial magnetohydrodynamic phenomena. Further optical refinements and the development of advanced data processing algorithms are anticipated to enhance the measurement accuracy and overall performance of the line array detection scheme.
Reconfigurable skyrmion logic gates and diodes in the same synthetic antiferromagnetic nanotrack based on potential well inducting effect
Authors: Xu Min , Chen Wenlong , Hu Changjing , Chen Yuliang , Zhao Xiaoyu , Ning Jianyu , Wang Yifan , Zhang Jinyu
Published: December 2024

Magnetic skyrmions are nanoscale spin configurations with topological protection properties, which have broad application potential in the next generation of spintronic devices. Here, we report on the current-driven dynamics of skyrmions in synthetic antiferromagnetic (SAF) nanotracks with voltage-controlled magnetic anisotropy. This study reveals that, compared to a single skyrmion, when two skyrmions are created simultaneously, the inductive effect of the potential well generated by the voltage gate on the skyrmions is partially counteracted by the interaction between the skyrmions, resulting in a reduction in the critical current required for the skyrmions to pass the voltage gate. Moreover, the critical current required for the forward moving skyrmions to depin from the voltage gate is significantly lower than that required for the reverse moving skyrmions. Based on the dynamic behavior of skyrmions, we have proposed and achieved the skyrmion logic AND, OR, NOT, NAND, NOR gates and the diodes on the same SAF nanotrack by micromagnetic simulation, in which the logic NOT, NAND, and NOR gates are realized in a reconfigurable way. Furthermore, we have also investigated the feasibility of reconfigurable logic gates and diodes at finite temperatures. Our results are beneficial for the design and development of non-volatile spintronic devices with integrated multifunctionality and ultra-low energy consumption.
Numerical investigation of the bridging and current flow of a positive DC streamer using a 1.5D model
Authors: Strobel L R , Guerra-Garcia C
Published: December 2024

Single streamers, at nanosecond-timescales, can be simulated using detailed computational models with a high-dimensional representation. These models are computationally impractical for parametric explorations and simulation of longer times, that can follow many-streamer pulsations and the influence of one streamer burst on the next. This work develops a 1.5D model of a positive DC streamer for simulations beyond the electrode-gap bridging phase, and uses it to parametrically explore the impact of different terms and operational parameters. The geometry of interest is that of a tip-to-plane electrode configuration under DC voltage, and the simulation is followed for the duration of one current pulse (order 500 ns). The numerical model uses an axisymmetric boundary element method to solve for the electric field, as well as a ‘stack’ of 3 different transient solvers to improve efficiency and allow solving over longer timescales. The model is able to resolve the development of the cathode sheath during the streamer bridging phase using a kinetic flux boundary condition. It also gives qualitative agreement to current waveforms using an equivalent experimental setup. The different phases of the current pulse (streamer propagation, bridging, and current-flow phase) are discussed in detail.
Fault diagnosis of rolling bearing with variable working conditions in noisy environment based on dynamic soft threshold and attention mechanism
Authors: Li Ankang , Yao Dechen , Yang Jianwei , Zhou Tao
Published: December 2024

In response to the complex and variable working conditions faced by rolling bearings during actual operation, as well as the issue of vibration signal acquisition being easily disrupted by noise interference, the study describes the multi-source domain anti-noise rolling bearing failure detection approach (MEDThresNet). The purpose of this model’s design is to solve the challenges of a lack of corresponding sample data and noisy signals in bearing fault classification. Using multi-condition source domains, as opposed to a single working condition source domain data, might help gain information from diverse domains and minimize overreliance on data from a specific working condition source domain. This can significantly increase the model’s generalization and robustness, and fault identification accuracy. Convolutional modules with soft thresholding and attention mechanisms are applied in this network structure. Soft thresholding helps to suppress noise in the data during the training phase while keeping critical characteristics. The attention mechanism, on the other hand, allows the model to automatically focus on the critical areas of the defect information in the bearing vibration signals throughout the training phase, hence improving the network’s performance and generalization ability. Furthermore, the network aligns the joint distribution of source and target domain data across many particular levels using the joint maximum mean discrepancy approach to accomplish unsupervised domain adaptation. This allows the network to successfully transfer information learnt from the source domain data of the faulty bearing to the target domain of the faulty bearing, improving the model’s generalizability on the target domain. This research tests the network on two datasets with varied working conditions, CWRU and Ottawa, and the findings demonstrate that the network is high robustness and accurate for multi-source domain transfer diagnosis in noisy environments.
A quantification method for micro-defect size in copper foil based on motion-induced eddy current signal characteristics
Authors: Wei Bingkun , Wen Shuzhi , Peng Lisha , Zhang Jinghua , Han Zheng , Huang Songling
Published: December 2024

Lithium-ion batteries are recognized as a critical technology for modern energy storage, with copper foil frequently used as the current collector for the anode. However, the presence of micro-defects in copper foil can significantly degrade the electrochemical performance of lithium-ion batteries. Therefore, a method capable of accurately detecting micro-defects during high-speed production and subsequently quantifying their sizes is required. Motion-induced eddy current (MIEC) technology, characterized by relative motion, has been employed to detect defects in conductive materials during high-speed movement. However, limited research has been conducted on the quantification of defect sizes based on MIEC signals. In this study, a novel method for quantifying the size of micro-defects in copper foil based on MIEC signal features is proposed. Wavelet soft-thresholding and morphological filtering are combined to effectively remove high-frequency noise and signal fluctuations caused by variations in lift-off distance. Eight distinct features of the micro-defect-induced eddy current signals are defined, and a feature dataset for various sizes of copper foil micro-defects at different motor speeds is established. The IVY algorithm, known for its excellent optimization speed, is used to optimize the hyperparameters of a conventional convolutional neural network (CNN)-bidirectional long short-term memory (BiLSTM)-Attention model, resulting in the development of the IVY-CNN-BiLSTM-Attention model. The experimental results demonstrate that superior performance is achieved, with accurate micro-defect size quantification in copper foil.
Refractive index measurement based on laser FMCW self-mixing interferometry
Authors: Chen Jinyuan , Liu Bin
Published: December 2024

In this paper, we propose a new method for measuring material refractive index using frequency-modulated continuous-wave (FMCW) self-mixing interferometry (SMI) in conjunction with all-phase fast Fourier transform (apFFT). Leveraging the simplicity and compactness of SMI technology, our method involves placing a material specimen with known thickness perpendicular to the laser within an external cavity. The refractive index directly influences the optical length of the external cavity, allowing us to extract refractive index information from the frequency of the FMCW SMI signal. To enhance the accuracy of frequency information, we introduce apFFT to mitigate spectrum leakage. Simulation results show that the estimated frequency relative error is less than 0.07% at a signal-to-noise ratio of 10 dB. In experimental validation using acrylic plate and quartz glass, the final refractive index relative error is found to be no more than 0.047% and 0.014% respectively. This method offers an effective means to measure material refractive index with simple operation and high accuracy.
Hemodynamic effects of bifurcation and stenosis geometry on carotid arteries with different degrees of stenosis
Authors: Guo Yuxin , Yang Jianbao , Xue Junzhen , Yang Jingxi , Liu Siyu , Zhang XueLian , Yao Yixin , Quan Anlong , Zhang Yang
Published: December 2024

Objective. Carotid artery stenosis (CAS) is a key factor in pathological conditions, such as thrombosis, which is closely linked to hemodynamic parameters. Existing research often focuses on analyzing the influence of geometric characteristics at the stenosis site, making it difficult to predict the effects of overall vascular geometry on hemodynamic parameters. The objective of this study is to comprehensively examine the influence of geometric morphology at different degrees of CAS and at bifurcation sites on hemodynamic parameters. Approach. A three-dimensional model is established using computed tomography angiography images, and eight geometric parameters of each patient are measured by MIMICS. Then, computational fluid dynamics is utilized to investigate 60 patients with varying degrees of stenosis (10%–95%). Time and grid tests are conducted to optimize settings, and results are validated through comparison with reference calculations. Subsequently, correlation analysis using SPSS is performed to examine the relationship between the eight geometric parameters and four hemodynamic parameters. In MATLAB, prediction models for the four hemodynamic parameters are developed using back propagation neural networks (BPNN) and multiple linear regression. Main results. The BPNN model significantly outperforms the multiple linear regression model, reducing mean absolute error, mean squared error, and root mean squared error by 91.7%, 93.9%, and 75.5%, respectively, and increasing R
2 from 19.0% to 88.0%. This greatly improves fitting accuracy and reduces errors. This study elucidates the correlation and patterns of geometric parameters of vascular stenosis and bifurcation in evaluating hemodynamic parameters of CAS. Significance. This study opens up new avenues for improving the diagnosis, treatment, and clinical management strategies of CAS.
Velocity-space analysis of fast-ion losses measured in MAST-U using a high-speed camera in the FILD detector
Authors: Velarde Lina , Rivero-Rodríguez J F , Galdón-Quiroga J , Williams T , Rueda-Rueda J , Cano-Megías P , Chacartegui R , García-Muñoz M , Blackmore S , McClements K G , Sanchís L , Viezzer E ,   the MAST Upgrade team,   the EUROfusion Tokamak Exploitation team
Published: December 2024

A fast-ion loss detector (FILD) was installed for the first time at the mega amp spherical tokamak—upgrade (MAST-U) spherical tokamak during its upgrade in 2021. A new CMOS camera was installed in the MAST-U FILD acquisition system to provide high spatial resolution (1.1 MPx) with an acquisition frequency of up to 3.5 kHz. This camera has enabled the systematic analysis of the velocity-space of the fast-ion losses measured in MAST-U presented in this manuscript. The main parameters that determine the FILD measurement have been analysed to maximise the signal in the detector: the orbit-following code ASCOT predicts an inverse relation between the FILD signal and the probe’s relative distance to the separatrix. This prediction has been validated experimentally, enabling the measurement of fast-ion losses in the flat-top phase of the discharge; furthermore, ASCOT simulations show a big impact of the edge safety factor (q
95) on the toroidal deposition of the prompt losses, indicating that the signal in the MAST-U FILD can be maximised by running scenarios with

|

q

95

|

<
6

. This prediction was validated experimentally by a scan in the toroidal magnetic field. The experimental resolution of the MAST-U FILD has been evaluated for a typical MAST-U scenario with 750 kA plasma current. The results show that the diagnostic resolution is in the order of 0.5 to 1 degree in pitch angle, and of 1 to 3 cm in gyroradius in current scenarios. A systematic analysis of the velocity-space of the losses shows that the measured gyroradii of the prompt losses match those of the neutral beam injector injection energies within the resolution of the diagnostic. The experimentally measured pitch angles have been compared with ASCOT simulations, and it has been found that the agreement is better for scenarios heated with the on-axis beam, since this beam enables measurements of the magnetic field pitch angle. This analysis has been applied to a discharge where type-III ELM-induced fast-ion losses were measured, showing that the ELMs result in an increase in the FILD signal, and that the losses are coming from passing orbits.
Characterizing the negative triangularity reactor core operating space with integrated modeling
Authors: Wilson H S , Nelson A O , McClenaghan J , Rodriguez-Fernandez P , Parisi J , Paz-Soldan C
Published: December 2024

Negative triangularity (NT) has received renewed interest as a fusion reactor regime due to its beneficial power-handling properties, including low scrape-off layer power and a larger divertor wetted area that facilitates simple divertor integration. NT experiments have also demonstrated core performance on par with positive triangularity (PT) high confinement mode (H-mode) without edge-localized modes (ELMs), encouraging further study of an NT reactor core. In this work, we use integrated modeling to scope the operating space around two NT reactor strategies. The first is the high-field, compact fusion pilot plant concept Modular, Adjustable, NT ARC (MANTA) (The MANTA Collaboration et al 2024 Plasma Phys. Control. Fusion
66 105006) and the second is a low field, high aspect ratio concept based on work by Medvedev et al (Medvedev et al 2015 Nucl. Fusion
55 063013). By integrating equilibrium, core transport, and edge ballooning instability models, we establish a range of operating points with less than 50 MW scrape-off layer power and fusion power comparable to PT H-mode reactor concepts. Heating and seeded impurities are leveraged to accomplish the same fusion performance and scrape-off layer exhaust power for various pressure edge boundary conditions. Scans over these pressure edge conditions accommodate any current uncertainty of the properties of the NT edge and show that the performance of an NT reactor will be extremely dependent on the edge pressure. The high-field case is found to enable lower scrape-off layer power because it is capable of reaching high fusion powers at a relatively compact size, which allows increased separatrix density without exceeding the Greenwald density limit. Adjustments in NT shaping exhibit small changes in fusion power, with an increase in fusion power density seen at weaker NT. Infinite-n ballooning instability models indicate that an NT reactor core can reach fusion powers comparable to leading PT H-mode reactor concepts while remaining ballooning-stable. Seeded krypton is leveraged to further lower scrape-off layer power since NT does not have a requirement to remain in H-mode while still maintaining high confinement. We contextualize the NT reactor operating space by comparing to popular PT H-mode reactor concepts, and find that NT exhibits competitive ELM-free performance with these concepts for a variety of edge conditions while maintaining relatively low scrape-off layer power.
High-temperature condensation and many-body localization of blended ferrons in antiferromagnetic clusters
Authors: Jipdi M N , Vubangsi M , Nana B , Fai L C , Tchoffo M
Published: December 2024

This paper presents a multi-ferron system and analyzes the conditions under which it forms a localized many-body state. We determined the self-trapping potential of this system and showed that the ferrons pair up to form bound biferron states, which interact through their relative spin cloud and settle into two different configurations mimicking the Bose-Einstein Condensate (BEC) and Bardeen-Cooper-Schrieffer (BCS) states. The external B-field strengthens the magnetic coupling, favouring the ferrons' pairing. It also creates a vortex, providing good confinement of the particles and favouring condensation. The system’s state functions are well described by the nonlinear Schrödinger equation, whose solution is a bell-shaped soliton representing the density of particle distribution in the condensate. The system’s critical temperature is obtained as a function of the biferron energy shift and thus strongly depends on the applied field.
Performance assessment of a JF-CP-TFET for hydrogen gas sensing applications
Authors: Kumar Bind Mukesh
Published: December 2024

In this paper, a junction-free charge plasma tunnel field-effect transistor (JF-CP-TFET) is proposed and analyzed for the first time to sense hydrogen (H2) gas. Using junction-free and charge-plasma approaches, the proposed JF-CP-TFET-based sensor minimizes random dopant fluctuations, a large thermal budget requirement, and complex processes in the semiconductor sensor production process. The sensing performance of the JF-CP-TFET-based gas sensor is demonstrated by analyzing changes in the work function of the gate of palladium (Pd) catalytic metals, which are proportional to the pressure of H2 gas exposed at the metal gate surface. The presence of H2 gas has been demonstrated by variations of the DC/AC parameters of the proposed sensor, such as carrier concentration, energy band, electric field, transfer characteristics, threshold voltage (VTh), and subthreshold swing (SS). The sensitivity of the JF-CP-TFET-based sensor has been eValuated in terms of drain current (IDS), ION/IOFF ratio, VTh, and SS change in the presence and absence of H2 gas molecules. The sensing capabilities of the proposed JF-CP-TFET-based gas sensor demonstrate that it could potentially be employed for H2 gas detection with excellent sensitivity and reliability.
The electronic, optical and transport properties of BaAgMF (M = Se, Te) quaternary chalcogenides: a systematic first-principles study
Authors: Salman Khan Muhammad , Gul Banat , Mohamed Abdelhay Salah , Abbas Faheem
Published: December 2024

Silver-based quaternary semiconductors show distinctive characteristics such as adjustable optical response and high stability in their thermoelectric nature. Here we performed the first principles investigation that explains the complex relationship between the structural, optoelectric, and thermoelectric features of BaAgMF (M = Se, Te) quaternary chalcogenides. The valence band maximum and conduction band minimum were located at the high symmetry Γ-point of BZ, resulting in a direct band gap nature. The projected energy band gaps calculated using the PBE-GGA and TB-mBJ potentials were 1.24 eV and 2.56 eV for BaAgSeF and 1.49 eV and 2.52 eV for BaAgTeF materials. The components of the complex dielectric function and the vital optical parameters are investigated to determine their potential usage in optoelectronic applications. Peaks in ε
1(ω) decrease and approach the negative energy region for both materials, indicating metallicity. The studied materials are appropriate to be used for thermoelectric applications, as demonstrated by significant and notable thermoelectric properties. The present studies can support understanding the possible applications of these materials in advanced optoelectronic devices and pave the way for a wide range of technologies.
Innovative urea formation using microwave plasma-water interaction: a study on reactive species and plant growth
Authors: Rathore Vikas , Nigam Kushagra , Patil Chirayu N , Nisoa Mudtorlep , Nema Sudhir Kumar
Published: December 2024

This study explores the production of urea using microwave (MW) plasma-water interaction with air, N2, CO2, and a N2 + CO2 gas mixture to generate plasma-activated water (PAW). After 180 s of plasma exposure, air plasma reduced the pH to 3.3 and increased the oxidizing potential by 127.1%, making the water acidic and oxidizing, while the N2 + CO2 plasma raised the pH to 10.1 and reduced the oxidizing potential by 33.8%, creating basic and reducing conditions. PAW from air plasma produced the highest NO2
− (51 mg l−1) and NO3
− (295 mg l−1) concentrations, while the N2 + CO2 mixture generated the most NH4
+ (2250 mg l−1), and CO2 plasma produced the most CO3
2− ions. Notably, urea formation (plasma urea) was observed only with CO2 and N2 + CO2 plasmas, attributed to the formation of stable compounds like NH4
+ and NH2COO−. In this process, NH4
+ ions formed via the reaction between atomic nitrogen and water, and their subsequent reaction with NH2COO− ions in the aqueous phase led to urea synthesis. The N2 + CO2 plasma produced 2991% more urea than CO2 plasma. Plasma urea enhanced seed germination and plant growth, increasing germination rates for carrots by 10.67% and coriander by 15.6%. Shoot lengths grew by 38.6% for carrots and 30.8% for coriander, while root lengths improved by 24.24% and 37.5%, respectively, compared to controls. This study highlights MW plasma-water interaction as a sustainable, energy-efficient alternative to conventional urea production, offering significant environmental benefits and improved agricultural performance.
A dual-channel SPR sensor based on both sides polished PCF with composite films for wide-range detection of RI and temperature
Authors: Du Hao , Li Kaifeng , Li Shuguang
Published: December 2024

A dual-channel surface plasmon resonance (SPR) fiber sensor for detecting the refractive index and temperature has been presented in this paper. The fiber is polished on both sides to form two planes, and on one side, a refractive index measurement channel is formed by coating MoS2 film on the surface of a silver film. On the other side, a polydimethylsiloxane (PDMS) layer is coated on the surface of the silver film as the temperature sensing channel. The results showed that the sensor has a maximum spectral sensitivity of 23000 nm RIU−1 at a liquid RI of 1.333–1.415 and a maximum spectral sensitivity of 12.3 nm °C−1 at a temperature of −20 °C to 90 °C. The results show that this sensor, with high sensitivity and wide-range detection, has important applications in the fields of organic chemistry, modern medicine and environmental detection. It also has a momentous reference significance for the design of SPR sensors that can realize multiparameter sensing.
Enhancing the electronic and optical properties of germanium nanoclusters through alkali metal doping: a case study on Na2
Authors: Trivedi Ravi , Makarios Paul S Prince , Ray Shakti S , Mishra Vikash
Published: December 2024

In the present study, we have examined the key insight into structural, electronic, and optical properties of Na2 doped germanium nano-cluster using density functional theory. Analysis of binding energy (BE) indicates enhanced thermodynamical stability increases with cluster size, where Ge5Na2 and Ge10Na2 exhibiting highest BE. Second order energy suggest that cluster with n = 2, 5, 6, and 9 are most stable while thpse with n = 3, 4, and 7 shows lower stability. Embedding energy (EE) shows decreases curve with cluster size indicating large clusters are more favourable for Na encapsulation. Large HOMO–LUMO gap ranges from 1.4 to 3.2 eV illustrate semiconductor nature of clusters. Further investigation of hyperpolarizability suggesting non-linear optical (NLO) activity for GenNa2 (n = 1–4), while lower NLO features shown in high symmetry clusters with n = 5 and 6. These results imply that GenNa2 clusters have potential uses in optoelectronic and semiconductor devices.
Optical, structural, and vibrational properties of In2S3 thin films by sputtering-RF for applications in optoelectronics devices
Authors: López-Sánchez A F , Mendoza-Pérez R , Fierro-López J A , G Zayas-Bazan P , Sastré-Hernández J , Aguilar-Hernández J R , Contreras-Puente G S
Published: December 2024

Experimental results on the crystalline orientation properties, energy band gap, and Raman vibrational modes of Indium Sulfide (In2S3) thin films grown by Sputtering in Radio Frequency mode are presented. The In2S3 thin films were grown at 25, 200, and 300 °C; thereafter the samples were thermally annealed in air for 30 min at 450 °C, in order to improve their crystalline and physical properties. Energy dispersive x-ray spectroscopy results showed that the β-In2S3 crystallographic phase became predominant as the substrate temperature increased. For the optical transmittance spectra, it was observed that the deposited In2S3 thin films at 300 °C and with thermal annealing showed an increase in their band gap energy of nearly 60 meV. The direct energy bandgap of In2S3 films varied in the range 2.76–2.82 eV. The scanning electron microcopy image and elemental analysis shows a better morphology, and an increase in O and Sn when the In2S3 samples were subjected to thermal annealed and the substrate temperature increased, respectively. Photoluminescence spectra were obtained at room temperature and showed two emission bands around 1.75 (709 nm) and 2.35 eV (527 nm), one related to interstitial indium donor sites (Ini) and oxygen acceptor vacancies (OVs), and the second to an emission band corresponding to the transition sulfur donor-indium acceptor. As the substrate temperature increased and thermal annealing of In2S3 was performed, the 1.75 eV emission bands increased in intensity with respect to the 2.35 eV band. From the Raman measurements, it was observed that the vibrational peaks were better defined as the substrate temperature increased and In2S3 underwent thermal annealing. In addition, to study the spinel-like defect structure, the peaks corresponding to the five main vibrational modes of In2S3 were identified as the Alg mode, Eg mode, and three modes of the F2g species.
Protonated molecular clusters: promoting molecular complexity*
Authors: Comte Denis , Lavy Léo , Parrado-Ospina Laura , Lissillour Hector , Bertier Paul , Calvo Florent , Daniel Isabelle , Farizon Bernadette , Farizon Michel
Published: December 2024

Molecules identified in Space display a diversity greater than ever, yet the mechanisms responsible for this complexity remain largely unknown. The extreme conditions faced by these molecules under astrophysical conditions raise several questions about their persistence and evolution. In this work, we explore the role of gas-phase protonated molecular dimers, which act both as protectors of existing molecules and as promotors in the emergence of new species. Experiments were conducted using the DIAM irradiation device on four protonated dimers of astrophysical interest, namely the pyridine, methanol, glycine pure dimers and the diglycine-glycine mixed dimer. Analysis of the observed relaxation channels following an energy deposition mimicking cosmic radiation reveals three main mechanisms of evaporation, covalent bond breaking, and unimolecular reaction. Focusing on the latter, our experiments combined with quantum chemical calculations of the relevant pathways shed new light onto the role of the protonation site on the reactants.
Optimization of Skanavi model and its application to high permittivity materials
Authors: Luo 罗 Hao 昊 , Qin 秦 Xinrui 新瑞 , Geng 耿 Kejia 可佳 , Kong 孔 Cuncun 存存 , Cheng 成 Pengfei 鹏飞
Published: December 2024

A novel method is introduced to optimize the traditional Skanavi model by decomposing the electric field of molecules into the electric field of ions and quantitatively describing the ionic-scale electric field by the structural coefficient of the effective electric field. Furthermore, the optimization of the Skanavi model is demonstrated and the ferroelectric phase transition of BaTiO3 crystals is revealed by calculating the optical and static permittivities of BaTiO3, CaTiO3, and SrTiO3 crystals and the structure coefficients of the effective electric field of BT crystals after Ti4+ displacement. This research compensates for the deficiencies of the traditional Skanavi model and refines the theoretical framework for analyzing dielectric properties in high permittivity materials.
Research on Temperature Control Anti-cracking in the Main River Bed Dam Section of Concrete Gravity Dams in the Cold Area
Authors: Jiang Rui , Li Xiulin , Xia Shifa , Cao Shiyue
Published: December 2024

Cracks have always been a difficult problem in the construction and operation of water conservancy projects. Once cracks occur in concrete dams, it will have an impact on the appearance, structural bearing capacity, waterproofing, durability and service life of the dams. Taking the 9# typical retaining dam section of SETH Dam in Xinjiang as an example, this paper uses the three-dimensional finite element method to simulate the temperature field and stress field of the typical dam section during construction and operation, considering the actual pouring progress of the dam and various temperature control measures taken during construction. The results show that the thermal insulation measures adopted in this project have good effects. According to the analysis results, some construction suggestions are put forward, such as strengthening downstream thermal insulation and continuous monitoring, pouring upstream and downstream through warehouses, avoiding long interval and multiple empty pouring blocks, and avoiding exposure of overwintering surface.
Research on Testing Methods for the Modulus of Elasticity of Inorganic Binder-Strengthened Materials based on the Direct Strain Method
Authors: Feng Liu , Peng Zhang , Xinquan Xu , Changhua Liang
Published: December 2024

In order to obtain the elastic modulus of inorganic binder-stabilized materials based on the lateral method, firstly, by analyzing the constitutive model of the material’s elastic modulus, a testing system for the elastic modulus of inorganic binder-stabilized materials was constructed using pressure sensors, resistance strain gauges, and dynamic and static strain data testing systems. Secondly, based on the stability test of the strain gauges glued to the surface of the specimen, it is proposed that the zero drift of the strain gauges should be controlled within 0~6με within 6 minutes of the test load. Meanwhile, based on the experimental loading results, it is determined that the length of the strain gauge wire mesh used for modulus testing of inorganic binder-stabilised materials should be 30mm. Finally, elastic modulus testing of inorganic binder-stabilised materials was carried out on core samples drilled at Longxun highway in Guangdong Province. The modulus of elasticity of on-site drilled core specimens was determined by the test and the test results were at the same data level as those measured by the rigid ring method, indicating reliable analysis results. The experimental results show that the direct strain method with the elastic modulus testing system as the core can greatly reduce the test preparation time, ensure stable system operation and provide reliable test results.
Numerical study of cavitation characteristics in mixed-flow turbine
Authors: Zhang Guihua
Published: December 2024

In this paper, a numerical method is employed to investigate the internal flow of a mixed-flow turbine. A fully three-dimensional turbulence calculation method is adopted, utilizing the RNG k-ε turbulence model and SIMPLE algorithm. This simulation calculates the entire flow channel from the volute inlet to the draft tube outlet in a single comprehensive simulation. Based on the obtained three-dimensional cavitation flow field data, a flow field analysis of the runner’s internal flow is conducted, allowing for the computation of the critical cavitation coefficient. Additionally, the cavitation conditions at the runner outlet and within the draft tube under different cavitation characteristics are simulated.
The Combination of X-ray Ct and Multi-particle Finite Element Method for Powder Compaction
Authors: Che Lida , Wang Kai , Wu Zhanfang , Li Xiangyang
Published: December 2024

The macroscopic mechanical properties of granular materials are closely related to their microscopic properties, and studying the compression problem of powder is helpful for establishing a constitutive law of powder compaction process. This study utilized X-ray CT technology to investigate the 3D numerical analysis model of loose particle stacking and compaction based on MPFEM, and investigated the mechanical behavior of powder under compression. The results of MPFEM were experimentally verified through powder uniaxial compression experiments, and the results showed that the calculated results of MPFEM were in good agreement with the experimental results. The method of X-ray CT can effectively capture the geometric characteristics of powder particles, and the MPFEM can obtain the true characteristics of plastic deformation of powder bodies, which is an important means of developing powder compaction constitutive models.
Anisotropy study based on uniaxial compression experiments
Authors: Li Yanping , Zou Daqing , Chen Jiancheng , Yu Zhehan , Yu Wenhai , Lu Yunhui , Song Xinhong
Published: December 2024

Due to the striated sedimentary structure of laminated shale and the weak cementation between the layers, the damage patterns of laminated shale with different laminar angles have obvious anisotropy after being damaged by uniaxial compression experiments. In this paper, numerical simulations of uniaxial compression experiments are carried out based on GDEM-PDyna on laminated shale with laminar angles (0°, 15°, 30°, 45°, 60°, 75°, 90°) to explore the anisotropy of compression parameters of laminated shale. The results show that: (1) the uniaxial compressive strength of laminated shale with the increase of the angle of the laminate shows a “U” type change rule which decreases first and then increases, and the uniaxial compressive strength is the smallest when the angle of the laminate reaches 60°; (2) the Poisson’s ratio of the specimen of laminated shale with the increase of the angle of the laminate shows a process which decreases first and then increases, and the change of Poisson’s ratio with the angle of the laminate has the same relationship with the elasticity of the specimen, and it is the same as the change of the compression parameters. The change of Poisson’s ratio with the increase of lamination angle and the change of modulus of elasticity show a similar law, all of them have experienced the “U” type change rule of decreasing first and then increasing, and all of them reach the minimum value when the lamination angle is 30°. (3) The brittleness index of the laminated shale samples showed a “stepwise” decrease with the increase of the laminated angle.
Pressure Effect on Surface Roughness of Gradient Chromium-doped Diamond-like Carbon Coatings under High Temperature
Authors: Liu Xiequan , Liu Qiongxi , Yuan Miaomiao
Published: December 2024

In this paper, the pressure effect of surface roughness of four gradient chromium-doped diamond-like carbon (GCD-DLC) coating is systemically studied in argon annealing and high pressure annealing under high temperature. After HIPping annealing, the surface roughness of the hydrogen-free group (GCr and GCrSi) decreased slightly. However, for the two hydrogen-containing GCD-DLC coatings (DCr and DCrSi), especially the DCr coating, the roughness increased significantly. The changes in surface roughness of the hydrogen-free group and the hydrogen-containing group after high-pressure annealing are opposite. The surface roughness of the DCr coating increased significantly after 500°C HIP annealing, which is attributed to the pores on the coating surface. Only the surface morphology of the DCr coating exhibited significant changes. Numerous voids appeared on the surface of the DCr5H coating after 500°C HIP annealing. There were significant differences in the size and shape of these voids compared to those after 500°C argon annealing. The voids on the coating after argon annealing were larger than those after HIP annealing. The formation of pores is associated with the breaking of carbon-hydrogen bonds and the subsequent release of hydrogen. This is because high pressure slows down the transformation from sp3 carbon bonds to sp2 carbon bonds. Simultaneously, high pressure also slows down the release of hydrogen within the coatings.
Study on seismic performance of narrow flange special-shaped column with herringbone center support
Authors: Xia Bin , Peng Xiaotong , Xu Zhong
Published: December 2024

To solve the problems of convex beam, column and insufficient lateral stiffness of steel frame in residential buildings, a new type of steel special-shaped column with herringbone center support structure system is proposed by combining narrow flange special-shaped column with herringbone center support. The finite element model was established by ABAQUS to study the influence of parameters such as axial compression ratio and shear span ratio on the seismic performance of the structural system. The results show that the hysteresis curve of the structure is full, the lateral bearing capacity is high, and it has stable and reliable energy dissipation performance and plastic deformation ability. The structure has obvious yield and failure process under the action of horizontal reciprocating load, and the whole structure presents ductile failure. The plastic deformation of the structure is concentrated on the support, and the energy is consumed by the buckling of the herringbone central support, while the other structural members remain elastic. The increase of axial compression ratio will lead to a significant decrease in the horizontal bearing capacity and lateral stiffness of the structure. After the buckling of the brace, the structure also has good ductility. With the increase of shear span ratio, the lateral bearing capacity, lateral stiffness and ductility coefficient of the structure decrease.
66kv Modular Composite Material Emergency Repair Tower Simulation of Mechanical Performance and Experimental Study of Components
Authors: Wang Dezhi , Liu Minghui , Wu Xiong , Yu Xin , Wu Hanying , Wang Xingqian , Ye Qianjun
Published: December 2024

This paper details the design and performance evaluation of a 66kV modular insulated tower, aimed at enhancing the resilience and operational flexibility of power systems in extreme environments. The tower employs advanced composite materials, providing excellent mechanical strength. The design addresses various conditions, including line breaks, high wind speeds, and icing scenarios. Finite element analysis conducted using ANSYS software showed that the safety factor for the pole body is 2.14, indicating that the designed tower meets the safety factor requirements. Additionally, its excellent mechanical properties have been verified through mechanical property tests. The modular design facilitates rapid assembly and disassembly as needed across different contexts, significantly improving the efficiency and flexibility of emergency repair work, thus offering considerable benefits for power grid upgrades, maintenance, and disaster recovery. In summary, the 66kV modular insulated tower demonstrates its broad potential applications within modern power systems. The results of this study provide valuable references for power system design, especially in seeking more efficient and adaptable transmission repair solutions.
Gauge coupling unification in correlation study of proton decay
Authors: Džaferović-Mašić Emina
Published: December 2024

Proton decay has been studied for decades now as one of the consequences of grand unified theories. Among those theories exists SU(5) theory, firstly postulated by H. Georgi and S. Glashow [1]. However, there were some problems with this theory such as mass degeneration and coupling unification [1-3]. This created a need for an extension of an original SU(5) model – a specific minimal SU(5) [4-5]. In this minimal SU(5) there is a viable parameter space with achievable gauge coupling unification. In this article, we present the process of gauge coupling unification for three mass scales of new physics states in this model, namely for 1 TeV, 10 TeV, and 100 TeV.