bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct computations of viscoelastic moduli of biomolecular condensates
Authors: Cohen Samuel R. , Banerjee Priya R. , Pappu Rohit V.
Published: September 2024

Biomolecular condensates are viscoelastic materials defined by time-dependent, sequence-specific complex shear moduli. Here, we show that viscoelastic moduli can be computed directly using a generalization of the Rouse model that leverages information regarding intra- and inter-chain contacts, which we extract from equilibrium configurations of lattice-based Metropolis Monte Carlo (MMC) simulations of phase separation. The key ingredient of the generalized Rouse model is a graph Laplacian that we compute from equilibrium MMC simulations. We compute two flavors of graph Laplacians, one based on a single-chain graph that accounts only for intra-chain contacts, and the other referred to as a collective graph that accounts for inter-chain interactions. Calculations based on the single-chain graph systematically overestimate the storage and loss moduli, whereas calculations based on the collective graph reproduce the measured moduli with greater fidelity. However, in the long time, low-frequency domain, a mixture of the two graphs proves to be most accurate. In line with the theory of Rouse and contrary to recent assertions, we find that a continuous distribution of relaxation times exists in condensates. The single crossover frequency between dominantly elastic vs dominantly viscous behaviors does not imply a single relaxation time. Instead, it is influenced by the totality of the relaxation modes. Hence, our analysis affirms that viscoelastic fluid-like condensates are best described as generalized Maxwell fluids. Finally, we show that the complex shear moduli can be used to solve an inverse problem to obtain the relaxation time spectra that underlie the dynamics within condensates. This is of practical importance given advancements in passive and active microrheology measurements of condensate viscoelasticity.
A versatile system for the growth of porphyrin films via electrospray and molecular sublimation in vacuum and their multi-technique characterization
Authors: Goto F. , Calloni A. , Yivlialin R. , Bossi A. , Ciccacci F. , Duò L. , O’Shea J. N. , Bussetti G.
Published: September 2024

We present a system for the growth of molecular films in vacuum that exhibits high versatility with respect to the choice of molecular species. These can be either evaporated from powders or injected from solutions using an electrospray system, making it possible to handle particularly large and/or fragile molecules in a controlled environment. The apparatus is equipped with a reflectance anisotropy spectroscopy system for the in situ characterization of the optical response of the films and can be directly connected to a photoelectron spectrometer without breaking the vacuum. The system is conceived for the study and characterization of porphyrin films. Here, to showcase the range of possible analyses allowed by the experimental setup and test the operation of the system, novel results are provided on electrospray deposition on highly oriented pyrolytic graphite of Zn tetraphenyl porphyrins and Zn proto porphyrins, the latter featuring fragile side groups that make deposition from solution more attractive. In situ characterization is complemented by ex situ atomic force microscopy. Thanks to this multi-technique approach, changes in the film morphology and spectroscopic response are detected and directly related to the choice of the molecular moiety and growth method.
The entropic origin of the enhancement of liquid diffusion close to a neutral confining surface
Authors: Agosta Lorenzo , Briels Wim , Hermansson Kersti , Dzugutov Mikhail
Published: September 2024

It is known that, in the proximity of a neutral wall, liquids experience diffusion enhancement relative to their bulk diffusion, but the origin of this phenomenon is still unknown. We report a molecular dynamics simulation investigating the dynamics of a simple liquid in the proximity to a non-interacting smooth confining wall, which exhibits a strong diffusion enhancement within the liquid layers adjacent to the wall. We present an analysis of these results, demonstrating that the observed diffusion enhancement can be accounted for, with numerical accuracy, using the universal scaling law that relates the liquid diffusion rate to the excess entropy. These results show that the scaling law, which has so far only been used for the description of the bulk liquid diffusion, can be successfully used to describe the diffusion in liquids under nano-scale confinement.
Buffer gas cooled ice chemistry. II. Ice generation and mm-wave detection of molecules desorbed from an ice
Authors: Hager T. J. , Moore B. M. , Borengasser Q. D. , Kanaherarachchi A. C. , Renshaw K. T. , Radhakrishnan S. , Hall G. E. , Broderick B. M.
Published: September 2024

This second paper in a series of two describes the chirped-pulse ice apparatus that permits the detection of buffer gas cooled molecules desorbed from an energetically processed ice using broadband mm-wave rotational spectroscopy. Here, we detail the lower ice stage developed to generate ices at 4 K, which can then undergo energetic processing via UV/VUV photons or high-energy electrons and which ultimately enter the gas phase via temperature-programmed desorption (TPD). Over the course of TPD, the lower ice stage is interfaced with a buffer gas cooling cell that allows for sensitive detection via chirped-pulse rotational spectroscopy in the 60–90 GHz regime. In addition to a detailed description of the ice component of this apparatus, we show proof-of-principle experiments demonstrating the detection of H2CO products formed through irradiation of neat methanol ices or 1:1 CO + CH4 mixed ices.
Shock wave generated by composite energetic material driven by electrical non-penetrating wire explosion plasma
Authors: Meng Yang , Jin Wenyong , Zhang Ke , Ding Weidong , Zhang Yongmin
Published: September 2024

Underwater shock wave technology can realize dynamic rock fracture, which is helpful to increase oil and gas reservoir permeability. It can realize the efficient exploitation of medium and low maturity oil and gas resources. In practical application, the shock wave parameters require not only high intensity but also safety and controllability. To meet these requirements, insensitive composite energetic materials driven by electrical wire explosion plasma were proposed, which is one of the most promising methods. However, when in use, the load assembly process containing wires and energetic materials is complex. In this paper, a new type of energetic material load is proposed, using non-penetrating wire to drive composite energetic material. It can simplify the production process of the energetic load and produce acceptable shock wave parameters. The test results show that both the energy deposition of the wire and the shock wave intensity decrease under a non-penetrating wire structure. However, the shock wave intensity is still higher than that of the underwater electrical wire explosion. Based on schlieren diagnosis, it is found that the composite energetic material is gradually driven, and the energy release is not concentrated. In addition, the “non-wire” structure driving condition was discussed in contrast. Under this condition, the process of ionization channel establishment in composite energetic materials is random. The shock wave intensity is weak because the composite energetic material is in the process of slow detonation.
An explicit multilevel power turbulent wall function based on the de-thresholding Douglas–Peucker algorithm
Authors: Wang ZhiPing , Bi Lin , Luo CanYan , Zhang Hui , Yuan Xianxu , Tang Zhigong
Published: September 2024

Wall functions are extensively applied in engineering simulations with turbulence. They facilitate a significant increase in the scale of the grids next to the wall, which in turn reduces the total number of grids needed. This optimization enhances computational efficiency, making the simulation process more effective and streamlined. However, the current commonly used wall functions, such as the Spalding wall function, are an implicit expression that needs to be solved iteratively, which affects the computational efficiency, and the multilayer segmented wall function is not smoothly articulated, which affects the fidelity. In this study, based on flat plate direct numerical simulation (DNS) data, combined with structural ensemble dynamics theory, the de-thresholding Douglas–Peucker algorithm is introduced to construct an explicit wall function expression in the form of multilevel power exponential concatenated multiplication. The comparison of the new wall function against DNS data reveals that it demonstrates superior fitting accuracy in contrast to the traditional ones, and eliminates the need for manual calibration, reduces subjective influence, and enhances reliability. The numerical simulation outcomes for the flat plate boundary layer and a series of airfoils showcase the new wall function's exceptional accuracy, which not only meets but also surpasses the demanding standards of engineering practice.
M3XSe4 (M = V, Cr; X = S, Te) monolayers: Intrinsic high-temperature ferromagnetic semiconductors and half metals
Authors: Yao Xiaojing , Lian Huijie , Lu Jinlian , Zhao Xinli , Zhang Xiuyun
Published: September 2024

Creating low dimensional ferromagnetic (FM) semiconductors or half metals with strong FM orders is promising to meet the requirement for next-generation spintronics. However, most of the demonstrated FM semiconductors or half metals suffer from low Curie temperatures (TCs). Here, by first-principles calculations, we predict that the two-dimensional (2D) M3XSe4 (M = V, Cr; X = S, Te) monolayers are a type of intrinsic 2D ferromagnets with thermodynamical stability. Our results show that V3XSe4 (X = S, Te) monolayers are FM semiconductors with indirect bandgaps of 0.60 and 0.50 eV, respectively. Particularly, both structures are revealed to have high TCs of 387 and 770 K and suppress the application limit of room-temperature. In addition, Cr3XSe4 (X = S, Te) monolayers are FM half metals with 100% spin-polarized currents. Moreover, the electronic and magnetic properties of these M3XSe4 monolayers can be modulated by biaxial strains. V3TeSe4 monolayer can be tuned to be room temperature direct bandgap semiconductor under biaxial 1% tensile strain, and TC of V3SSe4 can be largely enhanced under compressive strains. Our results suggest that M3XSe4 monolayers are promising candidates for spintronic devices.
Evolution of trust in N-player trust games with loss assessment
Authors: Liu Yuyuan , Wang Lichen , Guo Ruqiang , Hua Shijia , Liu Linjie , Zhang Liang
Published: September 2024

Trust plays a crucial role in social and economic interactions, serving as the foundation for social stability and human cooperation. Previous studies have explored the evolution of trust between investors and trustees by constructing trust game models, incorporating factors such as network structure, reputation, and incentives. However, these studies often assume that investors consistently maintain their investment behavior, neglecting the potential influence of the investment environment on investment behavior. To address this gap, we introduce a loss assessment mechanism and construct a trust game model. Specifically, investors first allocate their investment amount to an assessment agency, which divides the amount into two parts according to a certain allocation ratio. One part is used for investment assessment, and the results are fed back to the investors. If the payoff from this portion exceeds the investors’ expected value, the remaining amount is invested; otherwise, it is returned to the investors. The results indicate that investors with moderate expectations are more likely to form alliances with trustworthy trustees, thereby effectively promoting the evolution of trust. Conversely, lower or higher expectations yield opposite results. Additionally, we find that as investors’ expected values increase, the corresponding allocation ratio should also increase to achieve higher payoffs.
Magnetic properties, critical behavior, and magnetocaloric effect of Nd1−xSrxMnO3 (0.2 ≤ x ≤ 0.5): The role of Sr doping concentration
Authors: Wang Haiou , Dong Fuxiao , Wang Haochen , Zhao Bojun , Wang Yan , Tan Weishi
Published: September 2024

Magnetic characteristics, magnetocaloric effect, and critical behavior of Nd1−xSrxMnO3 compounds by Sr doping (x = 0.2, 0.3, 0.4, 0.5) were studied. All samples maintained orthorhombic structures, but the space group changed from Pnma (No. 62) for x = 0.2, 0.3 to Imma (No. 74) for x = 0.4, 0.5. As Sr doping increased, the Curie temperature (TC), Curie–Weiss temperature (TCW), and magnetization increased, attributed to the double exchange (DE) interaction. A discrepancy between TCW and TC was observed due to the competition between polarons and DE interaction. The critical behavior was investigated systematically using the self-consistent (modified Arrott plots, MAP) method and the Kouvel–Fisher (KF) relation. The KF relation was suitable for the samples with x = 0.2 and 0.5, while the MAP method was suitable for the samples with x = 0.3 and 0.4. Among the Ising, XY, Heisenberg, and mean-field models, the samples with x = 0.2, 0.3, and 0.4 aligned more closely with the mean-field model, except for the x = 0.5 sample. Entropy change (−ΔSM) of Nd1−xSrxMnO3 (0.2 ≤ x ≤ 0.5) increased with the applied field, with the maximum value observed around TC. For the sample with x = 0.3, (−ΔSM) reached 4.315 J/kg K at μ0ΔH = 50 kOe, corresponding to a relative cooling power (RCP) of 280.48 J/kg. Remarkably, the x = 0.4 sample displayed (−ΔSM) of 3.298 J/kg K at μ0ΔH = 50 kOe near room temperature, with the RCP of 283.64 J/kg. These findings underscore the role of Sr doping in tuning the magnetic properties, critical behavior, and magnetocaloric effect of NdMnO3.
Magnetic casein/CaCO3/Fe3O4 microspheres stimulate osteogenic differentiation
Authors: Zhang Mingjie , Li Xiaolei , Lin Han
Published: September 2024

The quality of life is significantly impacted by bone defects, which calls for the creation of optimum restorative materials with particular qualities. Current repair materials, such as metal alloys, polymer scaffolds, and bone cement, have a number of drawbacks, such as poor fracture toughness, non-degradability, and insufficient osteogenic ability. To address these challenges, we designed a novel magnetic casein/CaCO3/Fe3O4 microspheres (CCFM), combining biodegradability, osteoinductivity, osteoconductivity, and osteogenesis properties together. In vitro studies confirmed the outstanding biocompatibility and osteogenic differentiation effects on MC3T3-E1 cells of CCFM, highlighting their potential as a promising bone regeneration platform for clinical applications. As a novel bone repair material with superparamagnetic properties, CCFM not only possess good osteoinductivity, osteoconductivity, and osteogenesis properties but also can remain in the lesion location for a long time under an external magnetic field, representing a significant advancement in the field of bone tissue engineering and offering new possibilities for effective bone defect remediation and patient care.
Inorganic/organic sublattice roles in band edge photodynamics of isoelectronically substituted hybrid semiconductors
Authors: Liu Wenjie , Wang Ziqin , Wu Huaxin , Zhang Xingyan , Fan Jiyang
Published: September 2024

Zero-dimensional organic–inorganic hybrid metal halides are unique semiconductors with fruitful physical properties. Usually, only the inorganic polyhedrons dominate the band edge electronic and photophysical properties of such hybrid semiconductors, whereas the organic components mainly act as structure-stabilizing units. Herein, we study the electronic structures and photodynamics of isoelectronically Br-substituted (I) zero-dimensional organic–inorganic copper halide semiconductors (C9H14N)3Cu3(BrxI1−x)6. They are composed of both inorganic [Cu3(BrxI1−x)6]3− units and organic C9H14N+ skeletons. It is surprising to find that unlike usual organic–inorganic metal halides, although the heavily isoelectronic substitution of halogen atoms in the (C9H14N)3Cu3I6 crystal leads to significant shrinkage of the lattice, it does not remarkably alter the bandgap and luminescence peak owing to the site-projected density of states as revealed by the density functional theory calculation. The inorganic units dominate the valence band edge quantum states, whereas the organic skeletons dominate the conduction-band edge states. However, the isoelectronic substitution significantly lowers the symmetry of the crystal, and as a result, the quantum transition probability at the band edge increases first and decreases then with increasing concentration of substituting bromine atoms. The (C9H14N)3Cu3(BrxI1−x)6 crystals exhibit dual-band luminescence with large Stokes shift and near-unity quantum yield. It arises from the excitons trapped by two kinds of centers. The critical participation of the organic skeletons in the electronic structures and band edge photodynamics refresh our knowledge of their roles in the hybrid semiconductors.
Calibration of binding energy and clarification of interfacial band bending for the Al2O3/diamond heterojunction
Authors: Liu J. W. , Teraji T. , Da B. , Koide Y.
Published: September 2024

Due to the presence of an intrinsic C 1s peak in diamond, it is impossible to calibrate its binding energies using the adventitious C 1s peak (284.8 eV) during x-ray photoelectron spectroscopy measurement. The absence of accurate binding energy measurement makes it challenging to determine the interfacial band bending for the oxide/diamond heterojunction. To overcome this issue, a net-patterned gold (Au) mask is applied to the boron-doped diamond (B-diamond) to suppress the charge-up effect and calibrate the binding energy using the standard Au 4f peak (83.96 eV). The B-diamond epitaxial layer shows downward band bending toward the surface with a valence band maximum of 0.85 eV. Upon the formation of Al2O3 using an ozone precursor through the atomic layer deposition technique, the B-diamond continues to exhibit downward band bending toward the Al2O3/B-diamond interface. However, the bending energy has reduced, potentially attributed to the modification of the oxygen vacancies on the B-diamond surface by the ozone precursor during the Al2O3 deposition.
Flexible memristors with low-operation voltage and high bending stability based on Cu2AgBiI6 perovskite
Authors: Chen Xinci , Yin Xiang , Li Zicong , Meng Lingyu , Han Xiaoli , Zhang Zhijun , Zhang Xianmin
Published: September 2024

Cu2AgBiI6 films were prepared by a one-step spin coating method, and flexible memristors with an Ag/PMMA/Cu2AgBiI6/ITO structure were constructed. The devices showed a bipolar resistive switching behavior with low switching voltage, which is beneficial for reducing energy consumption. Furthermore, this study found that the device exhibits an endurance of about 900 cycles, a higher ON/OFF ratio of over 103, a long retention time (∼104 s), and high stabilities against mechanical stress. Remarkably, the present flexible memristor displayed extraordinary flexibility and stability, with no significant change for the resistive switching behavior even at various bending angles or after undergoing 900 bending cycles. This study establishes that the lead-free halide perovskite Cu2AgBiI6 can be used for the resistive random-access memory of flexible electronics.
Long-lasting organics removal via •OH adsorbed transition metal flocs: Electron transfer-mediated H-bond and van der Waals force
Authors: Zhao Manshu , Wang Xinhua , Wang Shuguang , Lu Wenhui , He Maoxia , Gao Mingming
Published: September 2024

Homogenous advanced oxidation processes (AOPs) based on transition metal catalysts toward the activation of H
2
O
2
to hydroxyl radical (•OH) have been widely applied to organic pollutants removal, such as Fenton and Fenton-like processes. These transition metal catalysts mostly flocculate as the pH increases. It’s worth noting that the formed transition metal flocs are complex heterogeneous aggregations with active substances, providing diverse reaction spaces and interfaces. However, it is a challenge to distinguish the roles of transition metal flocs in the organic pollutants removal from homogeneous catalytic reactions. Herein, we unveiled a pathway for the long-lasting removal of organic pollutants via Cr flocs adsorbed with •OH (HO
•
-Cr flocs) using a stepwise method. First, adsorbed •OH (•OH
ads
) within the HO
•
-Cr flocs was proved to be the active site forming hydrogen bond (H-bond) and van der Waals force with organic pollutants. Then, the presence of switchable electron transfer between Cr and OH groups within the HO
•
-Cr flocs was revealed, contributing to the persistent existence of •OH
ads
and consequently ensuring the long-lasting organics removal. Further, this removal pathway of organic pollutants was confirmed during the leather wastewater treatment. These findings will complement a different pathway for organic pollutants removal via transition metal flocs and extend the lifetime of homogeneous AOPs based on transition metal catalysts, providing significant implications for their design and optimization.
Indicating engagement in online workplace meetings
Authors: Knight Dawn , O’Keeffe Anne , Mark Geraldine , Fitzgerald Christopher , McNamara Justin , Adolphs Svenja , Cowan Benjamin , Fahey Palma Tania , Farr Fiona , Peraldi Sandrine
Published: September 2024

Amid COVID-19 and the so-called “digital pivot”, online virtual communication is at the heart of our professional
and private lives. As we move into a post-COVID context, the affordances of the digital turn have shown that we can operate
professionally online but there is a need for better understanding of communication in the online workplace. This paper
contributes to our understanding of the dynamics of indicators of engagement in multi-party communication online, as evidenced by
a corpus-based multi-modal study. It showcases the importance of building naturally-occurring spoken corpora that go beyond
written transcription and include annotation of non-verbal behaviour. The work focuses on the incidence, frequency, position, and
function of spoken and head nod backchannels, exploring coordination and co-occurrence of these features in online talk. Findings
point to a changing profile of how engagement is displayed in online workplace meetings, which appears to be linked to the
functionality of platforms.
“I know this language, that language, and my language”
Authors: Kheirkhah Fogelberg Mina
Published: September 2024

Adopting a longitudinal dynamic perspective on the field of Family Language Policy (FLP), combined with insights
from language socialization, the current study explores five Iranian immigrant family members’ language ideologies, practices and
policies and aims to unfold the processes through which the language ideologies and policies are instantiated and negotiated.
Particular foci are the evolving nature of family language ideologies and practices, emphasizing the influence of children’s
language ideologies and societal interactions. Through detailed analyses of multiparty family interactions, the study argues the
significance of considering children’s language ideologies as integral to understanding of their language practices, moving beyond
a simplistic attribution of actions to mere ‘agency’.
Influence of Local Cation Order on Electronic Structure and Optical Properties of Cation-Disordered Semiconductor AgBiS2
Authors: Wang 王 Xiaoyu 啸宇 , Faizan Muhammad , Fu 付 Yuhao 钰豪 , Zhou 周 Kun 琨 , Zhang 张 Yilin 轶霖 , He 贺 Xin 欣 , Singh David J. , Zhang 张 Lijun 立军
Published: September 2024

Site disorder exists in some practical semiconductors and can significantly impact their intrinsic properties both beneficially and detrimentally. However, the uncertain local order and structure pose a challenge for experimental and theoretical research. Especially, it hinders the investigation of the effects of the diverse local atomic environments resulting from the site disorder. We employ the special quasi-random structure method to perform first-principles research on connection between local site disorder and electronic/optical properties, using cation-disordered AgBiS2 (rock salt phase) as an example. We predict that cation-disordered AgBiS2 has a bandgap ranging from 0.6 to 0.8 eV without spin-orbit coupling and that spin-orbit coupling reduces this by approximately 0.3 eV. We observe the effects of local structural features in the disordered lattice, such as the one-dimensional chain-like aggregation of cations that results in formation of doping energy bands near the band edges, formation and broadening of band-tail states, and the disturbance in the local electrostatic potential, which significantly reduces the bandgap and stability. The influence of these ordered features on the optical properties is confined to alterations in the bandgap and does not markedly affect the joint density of states or optical absorption. Our study provides a research roadmap for exploring the electronic structure of site-disordered semiconductor materials, suggests that the ordered chain-like aggregation of cations is an effective way to regulate the bandgap of AgBiS2, and provides insight into how variations in local order associated with processing can affect properties.
One-step pulsed laser deposition of carbon/metal oxynitride composites for supercapacitor application
Authors: Ghosh Subrata , Pagani Giacomo , Righi Massimilano , Hou Chengxi , Russo Valeria , Casari Carlo S
Published: September 2024

Advanced material composite of nanocarbons and metal-based materials provides a synergistic effect to obtain excellent electrochemical charge-storage performance and other properties. Herein, 3D porous carbon-metal oxynitride nanocomposites with tunable carbon/metal and oxygen/nitrogen ratio are synthesized uniquely by simultaneous ablation from two different targets by single-step pulsed laser deposition at room temperature. Co-ablation of titanium and vanadium nitride targets together with graphite allowed us to synthesize carbon-metal oxynitride porous nanocomposite and exploit them as a binder-free thin film supercapacitor electrode in aqueous electrolyte. We show that the elemental composition ratio and hence the structural properties can be tuned by selecting target configuration and by manipulating the ablation position. We investigate how this tuning capability impacts their charge-storage performances. We anticipate the utilization of as-synthesized various composites in a single PLD production run as next-generation active materials for flexible energy storage and optoelectronic applications.
Analysis of carrier dynamics and thermal effect of the GaAs photoconductive semiconductor switch in lock-on mode
Authors: Liu Chun , Xu Ming , Chen Shengtao , Sun Li , Zhang Liqing , Li Qianqian , Wang Jiahao
Published: September 2024

The lock-on effect of the gallium arsenide photoconductive semiconductor switch (GaAs PCSS) at repetition rate aggravates the current crowding and electric field distortion, which significantly increases the risk of switch damage or even failure. Therefore, it is of great significance to investigate the carrier transport and the heat generation mechanism for improving the performance and longevity of GaAs PCSS in lock-on mode. The internal physical process of an opposed-electrode GaAs PCSS at low optical energy and strong electric field is analyzed and discussed by experiment and simulation. A device-circuit hybrid simulation is employed to investigate the transient electric field, carrier concentration, and lattice temperature distribution within the GaAs PCSS in lock-on mode. The device temperature exhibits a positive correlation with the applied bias electric field, resulting in a peak temperature of 1037.25 K at an electric field of 38 kV cm−1. The temperature distribution within the GaAs PCSS indicates a greater possibility for thermal breakdown and damage near the electrodes.
Enhanced thermoelectric performance of AgCuTe-doped polycrystalline SnSe by lattice plainification
Authors: Wang Yajing , Wang Chao , Wang Xinxin , Cui Shengqiang , Hao Min , Wang Chunhui , Huang Xudong , Yang Gui
Published: September 2024

Polycrystalline SnSe, renowned for its environmental sustainability, holds promise as a significant thermoelectric material, attracting considerable research attention. This study focuses on the thermoelectric properties of p-type polycrystalline SnSe doped with silver copper telluride (AgCuTe). Our experimental results conclusively show that the decomposition products of AgCuTe not only fill Sn vacancies but also act as acceptors, thereby introducing additional hole carriers. This leads to a notable improvement in both carrier mobility and concentration. Importantly, the thermal conductivity of the doped samples remains largely unchanged, as the lattice flattening strategy significantly boosts electrical performance without affecting lattice thermal conductivity. Ultimately, the doped sample Sn0.97Se-0.5%AgCuTe resulted in a power factor of 6.2 mW mK−1 and a peak ZT value of 1.4 at 798 K, representing a 109% improvement in ZT value. All samples exhibits superior stability and reproducibility, emphasizing its reliability for practical applications.
Research on aquatic biological signal recognition based on mode decomposition and deep learning
Authors: Zheng Lijun , Yin Xiaomin
Published: September 2024

As an important research content in the field of marine biology and ecology, aquatic biological signal (ABS) recognition is of great significance for understanding marine ecosystems, protecting biodiversity, and monitoring environmental changes. To improve the recognition accuracy of ABS, this paper proposes a new ABS recognition method based on mode decomposition and deep learning. First, real ABS data were obtained from the public website, and some data were selected for the simulation experiment. Secondly, the signal is decomposed using improved variational mode decomposition by human evolutionary optimization algorithm, and the decomposed intrinsic mode function (IMF) set is classified into low complexity and high complexity IMF using improved Lempel–Ziv complexity and reverse permutation entropy. Then, mutual information is used to select double eigenvectors from low and high complexity IMF, respectively, and recognition is performed based on the double eigenvectors using weighted-convolutional neural network-bidirectional gate recursive unit-Attention model. Finally, the proposed ABS recognition method is applied to both chaotic and real signals, and additional proof of universality is performed using real signals. The result of the study shows that the accuracy of the proposed method for the recognition of chaotic and real signals is as high as 97.3% and 98.0%. In conclusion, the research on ABS recognition in this paper is successful and has a broad application prospect.
Federated transfer learning-based distributed fault diagnosis method for rolling bearings
Authors: Yang Guang , Su Juan , Du Songhuai , Duan Qingling
Published: September 2024

Current methods for bearing fault diagnosis often fall short in addressing data privacy concerns and typically rely on one-to-one transfer strategies, which are inadequate for achieving knowledge transfer in distributed environments. To address this issue, a distributed fault diagnosis method for rolling bearings based on federated transfer learning is proposed. This method ensures data privacy while integrating fault knowledge from multiple domains, thereby enabling more efficient knowledge transfer. Specifically, a domain adversarial neural network (DANN) is introduced as the base model within the federated learning framework. Additionally, maximum mean discrepancy (MMD) is incorporated into the DANN to enhance the transfer of fault knowledge. Finally, a dynamic weighting parameter update method based on MMD is designed to evaluate the feature discrepancies between source and target domains, thereby updating the parameters of the federated framework and achieving global model aggregation. Experimental results on two bearing datasets demonstrate that the proposed method excels in both distribution alignment and fault diagnosis.
Pedestal properties of negative triangularity discharges in ASDEX Upgrade
Authors: Vanovac B , Dunne M , Pütterich T , Happel T , Hobirk J , Silvagni D , Faitsch M , Lee K , Conway G D , Bielajew R , Yoo C , White A E , Bernert M , David P , Fischer R , Stieglitz D ,   the ASDEX Upgrade Team,   the EUROfusion WPTE Team
Published: September 2024

In this work, we explore the pedestal properties of negative triangularity discharges with upper triangularity of

δ
u

≈
−
0.35

and with both ion

∇
B

drift directions. In all cases, the discharges undergo a transition to H-mode with accompanying edge-localized modes (ELMs) that are not explained by the peeling-ballooning stability analysis alone. A variation in the ion

∇
B

drift direction is observed. A lower pressure gradient, shallower radial electric field well and increased temperature fluctuations are measured in the favorable case. In addition, irregular ELMs are present. This difference is more pronounced in electron cyclotron resonance heating (ECRH) plasmas compared to plasmas with combined neutral beam injection and ECRH. A comparative analysis between two discharges, featuring similar plasma parameters but varied shaping, suggests that an interplay between other parameters, such as magnetic shear, the timing of the auxiliary heating and shaping, might play a strong role in low- to high-confinement transitions. While the low shaping discharge maintained L-mode, the high shaping discharge entered H-mode with ELMs, contrary to expectations.
An enhanced electromagnetic energy harvester based on dual ratchet structure with secondary energy recovery
Authors: Liang Xing , Shi Ge , Xia Yinshui , Jia Shengyao , Sun Yanwei , Hu Xiangzhan , Yuan Mingzhu , Xia Huakang
Published: September 2024

With the continuous advancement of ultra-low-power electronic devices, capturing energy from the surrounding environment to power these smart devices has emerged as a new direction. However, most of the mechanical energy available for harvesting in the environment exhibits ultra-low frequencies. Therefore, the feasibility of self-powering low-power devices largely depends on the effective utilization of this ultra-low-frequency mechanical energy. Consequently, this work proposes an enhanced electromagnetic energy harvester based on a dual ratchet structure with secondary energy recovery. It converts ultra-low frequency vibrations into fast rotational movements by means of a rack and pinion mechanism, thus achieving high power output while maintaining a simple structure. Experimental tests demonstrate that the proposed harvester exhibits excellent power output under ultra-low-frequency external excitation. Under external excitation with a frequency of 1.5 Hz and an amplitude of 22 mm, with the optimal load matched at 20 Ω, the maximum power output reaches 598 mW, with a power density of 1572.65 μW cm−3. The secondary energy recovery power accounts for 34.4%, resulting in a 52.56% enhancement in the energy harvester’s output performance. Additionally, hand-cranking tests indicate that the fabricated prototype of the electromagnetic energy harvester can power some common electronic devices, including smartphones, showcasing significant application potential.
Spectroscopic analysis of tungsten spectra in extreme-ultraviolet range of 10-480 Å observed from EAST tokamak with full tungsten divertor
Authors: Zhang Wenmin , Zhang Ling , Morita Shigeru , Cheng Yunxin , Zhang Fengling , Hu Ailan , Zhou Chengxi , Li﻿ Zhengwei﻿ , Cao﻿ Yiming﻿ , Ma﻿ Jiuyang﻿ , Mitnik Darío , Jie Yinxian , Liu Haiqing
Published: September 2024

Tungsten spectra in extreme ultraviolet (EUV) wavelength range of 10-480 Å have been observed from high-temperature plasmas in Experimental Advanced Superconducting Tokamak (EAST) with full tungsten divertor using four fast-time-response EUV spectrometers of EUV_Short (5-45 Å), EUV_Long_a (40–180 Å), EUV_Long_c (130–330 Å) and EUV_Long_b (270–480 Å) and two space-resolved EUV spectrometers of EUV_Short2_d (45–70 Å) and EUV_Long2_d (40–130 Å). The wavelength of measured spectra is accurately calibrated based on several well-known spectral lines emitted from low-Z (He, Li, C, N and O), medium-Z (Fe and Cu) and high-Z (Mo) impurity ions. Measurements of the tungsten spectra were taken from discharges accompanied with a transient tungsten burst event, which creates a pulsed influx of tungsten atoms into the EAST plasma. The tungsten spectra observed before and after the burst event are carefully analyzed with temporal behavior and radial profile distribution of the tungsten line intensity. As a result, 213 tungsten lines are successfully confirmed in the spectra observed after the tungsten burst, and the results are summarized in tables. These tungsten lines include line identifications of 78 lines of W XXIII - W XLVI (W22+ - W45+) at 10–140 Å and 88 lines of W V - W IX (W4+ - W8+) at 160–480 Å, while 47 tungsten lines at 50–380 Å could not be clarified the transition. In addition, quasi-continuum spectra called unresolved transition array (UTA) from tungsten ions in low- and high-ionization stages are also analyzed in three wavelength ranges of 18–38 Å, 45–70 Å and 150–280 Å at which W XXIII - W XXXVIII (W22+ - W37+), W XXVII - W XLVI (W26+ - W45+) and W VI—W IX (W5+ - W8+) are dominantly emitted, respectively. Through the analysis it is found that charge state distributions of tungsten UTA at 140–220 Å significantly vary with decrease in the electron temperature. Ionization stages of all observed tungsten lines including both isolated and quasi-continuum lines are experimentally reconfirmed by comparing the radial intensity profile with the electron temperature profile. Finally, spectral lines useful for tungsten diagnostic in fusion plasmas are selected and marked in the tables.
Nonvolatile ferroelectric control of electronic properties of Bi2Te3
Authors: Ding 丁 Xusheng 旭升 , Li 李 Yunfei 云飞 , Kang 康 Chaoyang 朝阳 , Song 宋 Ye-Heng 业恒 , Zhang 张 Weifeng 伟风
Published: September 2024

Nonvolatile electric-field control of the unique physical characteristics of topological insulators (TIs) is essential for the fundamental research and development of practical electronic devices. Electrically tunable transport properties through gating materials have been extensively investigated. However, the relatively weak and volatile tunability limits its practical applications in spintronics. Here, we demonstrate the nonvolatile electric-field control of Bi2Te3 transport properties via constructing ferroelectric Rashba architectures, i.e., 2D Bi2Te3/α-In2Se3 ferroelectric field-effect transistors. By switching the polarization states of α-In2Se3, the Fermi level, resistance, Fermi wave vector, carrier mobility, carrier density and magnetoresistance (MR) of the Bi2Te3 film can be effectively modulated. Importantly, a shift of the Fermi level towards a band gap with a surface state occurs as switching to a negative polarization state, the contribution of the surface state to the conductivity then increases, thereby increasing the carrier mobility and electron coherence length significantly, resulting in the enhanced weak anti-localization (WAL) effect. These results provide a nonvolatile electric-field control method to tune the electronic properties of TI and can further extend to quantum transport properties.
Structural color of metallic glass through picosecond laser
Authors: Zhang 张 Yue’e 月娥 , Tong 童 Xing 星 , Yan 闫 Yuqiang 玉强 , Cao 曹 Shuo 硕 , Ke 柯 Hai-Bo 海波 , Wang 汪 Wei-Hua 卫华
Published: September 2024

The alteration in surface color of metallic glasses (MGs) holds great significance in the context of microstructure design and commercial utility. It is essential to accurately describe the structures that are formed during the laser and color separation processes in order to develop practical laser coloring applications. Due to the high oxidation sensitivity of La-based metallic glass, it can broaden the color range but make it more complex. Structure coloring by laser processing on the surface of La-based metallic glass can be conducted after thermoplastic forming. It is particularly important to clarify the role of structure and composition in the surface coloring process. The aim is to study the relationship between amorphous surface structural color, surface geometry, and oxide formation by laser processing in metallic glasses. The findings revealed that the periodic structure primarily determines the surface color at laser energy densities below 1.0 J/mm2. In contrast, the surface color predominantly depends on the proportion of oxides that are formed when energy densities exceed 1.0 J/mm2. Consequently, this study provides a novel concept for the fundamental investigation of laser coloring and establishes a new avenue for practical application.
Research on the HHO improved BP neural network fault prediction algorithm for distribution networks based on weather factors
Authors: Xu Yan , Dai Zikuo , Zhao Yi , Zhao Chenxing , Li Ming
Published: September 2024

Weather factors have a substantial impact on the operation and maintenance of the distribution network, but the current system fault prediction platform mainly focuses on the operating characteristics of the system, that is, the internal parameters, and rarely considers the external parameters. Firstly, by studying the fault data of the distribution network in a city in northern China caused by weather factors, this paper obtains the main weather factors affecting the reliability of power supply in this area. Then, the Harris Hawks optimization (HHO) improved BP neural network algorithm is used to establish the main reliability evaluation models suitable for this region, and based on this, the fault probability of this region is predicted under the target weather. Finally, the prediction results are compared with the actual fault data caused by weather factors in this area. The results show that both the PSO-BP algorithm and HHO-BP neural network algorithm achieve better prediction accuracy than the BP neural network algorithm, and the HHO-BP algorithm has better convergence speed.
Three-phase imbalance model based on energy storage device
Authors: Dong Jiawei , Sun Weiqing
Published: September 2024

In order to realize the goal of carbon peaking and carbon neutrality and integration of the source network, preventing and controlling three-phase imbalance is an indispensable subject. Aiming at the above requirements, this paper proposes and develops a model that takes energy storage devices as the core, integrating with the power grid to solve the three-phase imbalance. The model includes a power module with a detector, a rectifier-inverter module, an interactive module that can switch the charging mode and state, and a regulating and balancing module with PI control. This model can not only dynamically compensate the three phases quickly and accurately, minimize the three-phase imbalance, but also realize the functions of peak shaving and peak load regulation and provide guarantee and guidance for power grid operation.
Research on melon cascade drying technology to improve food safety
Authors: Zh Choriev A , Samadov O B , Tuxtaev Sh Q , Sabirdjanov R A , Sabirdjanova M A
Published: September 2024

The aim of the study is to study the process of cascade drying of melons. The prospects for the implementation of the melon drying process using IR convective heat supply are substantiated. Intensification of moisture transfer occurs due to pre-pulse IR treatment of high density power heat flow. The effect of heat flux emitted by IR lamps on the object of study was studied. Analyses have shown that in the proposed method, under the influence of IR rays, there is an intensive removal of moisture from the entire volume of the material. A decrease in air temperature leads to an increase in the duration of the drying process. And an increase in the density of the heat flux leads to overheating of the surface of the material layer.
Analysis of co-relation on LPBF process parameter on wear characteristics of Cu-Cr-Zr alloy
Authors: Saravana Kumar M , Jeyaprakash N , Yang Che-Hua
Published: September 2024

Copper alloy bearings, gears, and fasteners have a significant impact on industrial sectors. However, due to the defect formation and void generation during the manufacturing of copper alloy parts using (Laser Powder Bed Fusion) LPBF technique, the wear resistance of the copper alloy was significantly affected. Hence, the prime novelty of the current research is enhancing wear resistance by analyzing the interaction of combined LPBF parameters. In order to decrease cavity forms and reduce the wear rate of the printed Cu alloy components, the important LPBF process parameters such as Scan Velocity (SV) of 550, 750, and 950 mm s−1, Laser Power (LP) of 460, 540, and 620 W, and Re-melting Range (RR) of 5, 25, and 45% were selected and studied. The results of the experimental investigation were supported by the use of Grey Relation Analysis (GRA). A comparative study was conducted with five distinct parameter combinations to investigate the relative influence of each parameter on the relative density, wear rate and elastic modulus. The research findings verify that the application of optimal SV of 750 mm s−1 and RR of 45% with maximum LP of 460 W resulted in the maximum relative density of 99.91%, minimal wear rate of 0.52 × 10−5 mm3/Nm, and maximum elastic modulus of 140.22 GPa.
Evolution of tooth surface morphology and tribological properties of helical gears during mixed lubrication sliding wear
Authors: Zhao Jiang , Ma Chenbo , Li Zhengminqing , Yu Xiaofeng , Sheng Wei
Published: September 2024

In mixed lubrication, the interplay of lubricant flows, solid asperity contact, and material wear between tooth surfaces creates complex and unpredictable contact states on tooth surface. To comprehensively understand the interaction between the lubrication and wear characteristics of the rough tooth surfaces of helical gears, this study established a mixed lubrication sliding wear calculation model for helical gears based on the mixed elastohydrodynamic lubrication model and Archard’s model. Specifically, the study aimed to examine the effects of surface topography features on average film thickness, contact area ratio, and accumulated wear at the meshing point. The findings demonstrated that the texture and power spectral density distributions of a non-Gaussian reconstructed surface closely resembled those of the actual ground surface. Furthermore, for non-Gaussian rough surfaces, a larger wavelength ratio enhanced microwedge motion, which increased film thickness and reduced wear. Additionally, a negatively skewed surface demonstrated better lubrication performance compared to both positively skewed and Gaussian surfaces. This improved performance is evident in the smaller contact area ratio and lower accumulated wear value of the negatively skewed surface.