bluuebunny/crossref_metadata_2025 huggingface dataset:
Steering in the parameter space of a mode-locked laser
Authors: Repgen P. , Şura A. , Makey G. , Ilday F. Ö.
Published: October 2024

The specific control of individual mode-locking states in an ultrafast laser requires knowledge about its phase space. We use a Mamyshev oscillator as a model nonlinear system to present an all-electronic manipulation and steering of nonlinear states. The targeted evolution of the states resembles genetic evolution, illustrated by the Waddington landscape.
Highly-Stable Microwave Generation System Based on Figure-8 Mode-Locked Fiber Laser for Space Applications
Authors: Takeuchi Yuichi , Yamada Takahiro , Tanaka Yushi , Takagi Nozomu , Musha Mitsuru
Published: October 2024

We have developed a spaceborne optical frequency comb based on figure-8 mode-locked fiber laser for highly-stable microwave generation. Our low phase noise, robust and compact mode-locked laser has passed the environment tests for space applications.
Large mode area waveguide based high-energy passively Q-switched laser in silicon photonics
Authors: Singh Neetesh , Lorenzen Jan , Sinobad Milan , Wang Kai , Liapis Andreas C. , Frankis Henry , Gaafar Mahmoud A. , Haugg Stefanie , Francis Henry , Carreira Jose , Geiselmann Michael , Herr Tobias , Bradley Jonathan , Sun Zhipei , Garcia-Blanco Sonia M. , Kartner Franz X.
Published: October 2024

We demonstrate high energy Q-switched pulse generation with the help of a large mode area gain waveguide in a silicon photonics device. Output pulse energy >150 nJ and laser slope efficiency of 40% is shown.
Efficient yellow Dy:ZBLAN fiber laser with high-brightness diode-pumping at 450 nm
Authors: Demaimay Jonathan , Kifle Esrom , Loiko Pavel , Pau Florence , Recoque Gilles , Georges Thierry , Rault Thiphaine , Bodin Laurine , Camy Patrice , Braud Alain
Published: October 2024

A yellow continuous-wave Dy:ZBLAN fiber laser generates 92 mW at 575 nm with a record-high optical efficiency of 12% and high beam quality (M2 ~1.5) via pumping by two high-brightness blue 450-nm GaN laser diodes.
Challenges of temperature-dependent emission spectra measurement of thulium-doped fibers around 2 µm
Authors: Švejkarová Bara , Aubrecht Jan , Švejkar Richard , Grábner Martin , Clarkson W. Andrew , Peterka Pavel
Published: October 2024

Understanding temperature’s impact on spectroscopic properties in high-power thulium-doped fiber lasers is crucial for accurate numerical modeling. Our study discusses influence of thulium concentration and temperature-induced bend losses on emission spectra measurement.
Programmable burst-mode laser system delivering picosecond pulses with continuously tunable 1 to 7 GHz pulse repetition rate and up to 1 kW average power
Authors: Ye Hanyu , Pontagnier Lilia , Bendahmane Abdelkrim , Guandalini Annalisa , Kemnitzer Matthias , Gorjan Martin , Au Jürg Aus der , Loescher Andre , Bienert Florian , Ahmed Marwan Abdou , Santarelli Giorgio , Cormier Eric
Published: October 2024

We report on a laser producing bursts of GHz picosecond pulses with pulse repetition rate between 1 and 7.5 GHz, tens to thousands pulses per burst, 1 kW average power and inJ energy per burst. © 2024 The Author(s).
First demonstration of ultrafast-electron diffraction using a 3-GHz electro-optical comb generator as a UV photoinjector laser
Authors: Mahnke Christoph , Grosse-Wortmann Uwe , Hachmann Max , Hennicke Vincent , Li Chen , Meyer Jan , Pakendorf Tim , Flöttmann Klaus , Meents Alke , Hartl Ingmar
Published: October 2024

We demonstrate ultrafast-electron diffraction using an electro-optic comb-generator, emitting a 3 GHz train of ps pulses at 257 nm. This new operation mode improves electron coherence and reduces space-charge effects.
Non-linear Frequency Conversion Waveguides for Quantum Technology
Authors: Gates James C. , Davidson Noelia Palomar , D’Souza Matthew P. , Tawy Goronwy , Churchill Glenn , Mennea Paolo L. , Iveson Peter , Smith Peter G.R. , Gawith Corin B.E.
Published: October 2024

This talk will describe the fabrication of periodically poled lithium niobate non-linear waveguides for the emerging quantum technology industry. It will address the challenges of optical engineering high-efficiency frequency conversion devices for the field and their application.
Tunable 30W all-fiber laser emitting around 1850 nm
Authors: Poncelet Kentin , Guiraud Germain , Traynor Nick , Hilico Adèle , Santarelli Giorgio
Published: October 2024

We have demonstrated a tunable polarization maintaining thulium-doped fiber laser spanning the 1830nm-1880nm range with a fiber-coupled output power as high as 30W CW. The high- power booster stage is made using double clad fibers pumped with 793nm laser diodes.
Waveguides Written by Femtosecond Laser in CVD Diamonds
Authors: Perevoznik D. , Locmelis J. , Zuber D. , Glukhovskoy A. , Afentaki A. , Hinkelmann M. , Dencker F. , Wurz M. , Morgner U.
Published: October 2024

This research explores the creation of Type II waveguide configurations in diamond using femtosecond laser technology, focusing on the enhancement of light propagation using pin-structures and extensive parameter investigation, offering significant advances in the fields of photonics and quantum sensing.
50-fs pulse bursts via gain-managed nonlinear amplification
Authors: Maghsoudi A. , Repgen P. , Laçin M. , Şura A. , Ilday F. Ö.
Published: October 2024

We report the first gain-managed nonlinear amplifier operating in burst mode, delivering 50-fs, 600- nJ pulses. Due to a complex interplay between nonlinearity and gain, the amplification is influenced non- trivially and collectively by all the pulses within a burst.
Methods and Applications for Amplified Bursts of Picosecond-Spaced Ultrashort Pulses
Authors: Stummer Vinzenz , Kaksis Edgar , Flöry Tobias , Schneller Matthias , Zeiler Markus , Hu Hongtao , Pugžlys Audrius , Baltuška Andrius
Published: October 2024

Generating packages of picosecond-spaced ultrashort pulses yields various advantages in their application in nonlinear spectroscopy, micromachining, and plasma generation. We outline methods of burst amplification, with a focus on recent advancements in the generation and application of amplified pulse bursts.
Sub-20 fs, 80 W, up to 2 mJ Yb-based laser multi-pass-cell post-compression: Experimental and numerical results
Authors: Hergott Jean-François , Réau Fabrice , Lericheux Nicolas , Guer Matthieu , Marroux Hugo , Géneaux Romain , Tcherbakoff Olivier , Lepetit Fabien , Bresteau David , Ruchon Thierry , Salières Pascal , Auguste Thierry , D’Oliveira Pascal
Published: October 2024

We report here on the experimental pulse duration compression down to sub-20fs of up to 2mJ, 330fs pulses of an 80W Ytterbium laser, using argon-filled multi-pass-cell reproduced by numerical calculations stressing the role of the driver pulse profile.
Laser properties of hexagonal Yb-doped fluorapatite (FAP) transparent ceramics
Authors: Takimoto Kazuya , Sone Hiroyasu , Nakamura Shinki , Furuse Hiroaki
Published: October 2024

Transparent non-cubic hexagonal fluorapatite (Ca10(PO4)5F2: FAP) ceramics with an average grain size of approximately 100 nm are fabricated. The laser operation with slope efficiency over 8% was achieved from AR-coated Yb:FAP ceramics.
5-Watt level widely wavelength-tunable UV output from a frequency-doubled Alexandrite laser
Authors: Xiao Huaifeng , Damzen Michael J.
Published: October 2024

We demonstrate a record 5-Watt level, wavelength tunable, continuous-wave UV output based on a diode-pumped Alexandrite laser employing intra-cavity second harmonic generation. A wide wavelength tuning range from 364nm to 402nm was achieved.
Quasi-collinearly Pumped Fe:ZnSe Laser by ~4 µm Radiation
Authors: Říha A. , Jelínková H. , Doroshenko M. E. , Němec M. , Šulc J. , Vyhlídal D. , Badikov D. V.
Published: October 2024

Radiation with a wavelength of ~4 µm was used for quasi-collinear excitation of the Fe:ZnSe laser. The highest output energy was achieved at the optimal crystal temperature of 230 K with the generated radiation wavelength of ~4.5 µm.
Effect of the doping level on the 2.8-µm laser performance of Er3+:CaF2 crystals
Authors: Jambunathan Venkatesan , Loiko Pavel , Normani Simone , Basyrova Liza , Benayad Abdelmjid , Braud Alain , Hideur Ammar , Camy Patrice
Published: October 2024

The effect of doping level (0.1-10 at.%) on mid-infrared laser performance of Er:CaF2 crystals was investigated. The Er:CaF2 laser delivered 1.17 W at 2798 nm with 35.8% slope efficiency and was tuned across 2690-2830 nm.
Thermal management in quasi-waveguide amplifiers based on Herriott cells
Authors: Meyer Johann Gabriel , Zablah Andrea , Pronin Oleg
Published: October 2024

We present a new geometry for laser amplifiers with bulk laser gain media based on the quasi-waveguide property of Herriott cells. A proof-of-principle experiment and numerical simulations of the heat equation indicate a potential advantage in terms of thermal management.
Pulse non-linear post-compression with tunable wavelength by balancing SPM and SRS
Authors: Imani Aref , Kaksis Edgar , Bellissimo Alessandra , Pugžlys Audrius , Baltuška Andrius , Carpeggiani Paolo A.
Published: October 2024

In non-linear pulse spectral broadening via SPM, the original central wavelength is preserved; with SRS, it is red-shifted by an amount related to the broadening. We show that, by balancing SPM and SRS, red-shift and broadening can be tuned independently.
Machine learning method monitors non-Newtonian fluid flow in real time
Authors: Patrick Chris
Published: October 2024

Combining a contactless flow sensor with a neural-network algorithm allows accurate measurement and control of non-Newtonian fluids for healthcare and manufacturing applications.
Spatially defined microenvironment for engineering organoids
Authors: Zhang Yilan , Qi Fukang , Chen Peng , Liu Bi-Feng , Li Yiwei
Published: October 2024

In the intricately defined spatial microenvironment, a single fertilized egg remarkably develops into a conserved and well-organized multicellular organism. This observation leads us to hypothesize that stem cells or other seed cell types have the potential to construct fully structured and functional tissues or organs, provided the spatial cues are appropriately configured. Current organoid technology, however, largely depends on spontaneous growth and self-organization, lacking systematic guided intervention. As a result, the structures replicated in vitro often emerge in a disordered and sparse manner during growth phases. Although existing organoids have made significant contributions in many aspects, such as advancing our understanding of development and pathogenesis, aiding personalized drug selection, as well as expediting drug development, their potential in creating large-scale implantable tissue or organ constructs, and constructing multicomponent microphysiological systems, together with functioning at metabolic levels remains underutilized. Recent discoveries have demonstrated that the spatial definition of growth factors not only induces directional growth and migration of organoids but also leads to the formation of assembloids with multiple regional identities. This opens new avenues for the innovative engineering of higher-order organoids. Concurrently, the spatial organization of other microenvironmental cues, such as physical stresses, mechanical loads, and material composition, has been minimally explored. This review delves into the burgeoning field of organoid engineering with a focus on potential spatial microenvironmental control. It offers insight into the molecular principles, expected outcomes, and potential applications, envisioning a future perspective in this domain.
Free superfermions construction for the coupled super KP and super modified KP hierarchies
Authors: Chen Huizhan
Published: October 2024

In this paper, the Kac–van de Leur version of the coupled super KP (SKP) and super modified KP (SmKP) hierarchies are constructed. We define the tau functions as the orbit of a new group G(g) acting on the weight vectors, where G(g) is generated by elements in the even part of the tensor product of Clifford superalgebra and Grassmann algebra. The super Hirota bilinear equations of the coupled SKP and SmKP hierarchies are obtained by super boson-fermion correspondence of type A, and the bilinear identities with respect to the super Baker functions and tau functions in superbosonic Fock space are also constructed. Finally, the Miura transformation in terms of superfermions is also discussed.
Effect of Fe and Ni on the mechanical properties and deformation behavior of Co3Ti based alloys
Authors: Zhu Xinghua , Fang Yiheng , Feng Qingguo , Wang Ning , Xiao Lei , Xu Yi
Published: October 2024

In this work, the effect of random substitution modes of Fe and Ni on the stability and mechanical properties of Co3Ti-based intermetallics was investigated using first principles calculations through occupancy modes, electronic structures, energies, and elastic constants. The results show that FeCo type substitution favors ductility while NiCo type substitution favors strength. Compared to the above two types of substitution, FeTi type substitution is favorable for obtaining a balance between stability and ductility, but it is not easy to achieve energetically. Synergy of three types of substitutions enables stability and equilibrium mechanical properties of Co3Ti-based multi-component intermetallics. In addition, the anti-site substitution of neighboring Co and Ti atoms interchanging their positions may be a key step in the formation of FeTi type substitutions in terms of energy. This work provides useful data and insights into the design and utilization of Co3Ti-based multi-component intermetallics.
Role of surface charge convection on oblate droplets in different conductivity regimes
Authors: Basu Himadri Sekhar , Jena Santosh Kumar , Kondaraju Sasidhar
Published: October 2024

This paper presents a robust numerical model to simulate the electro-hydrodynamic flows of a neutrally buoyant liquid droplet suspending in another liquid for varying electrical conductivities ranging from near-dielectric to highly conductive fluids. The effect of such conductivity on the interfacial charge transport in the droplets has been investigated. The model is first validated with the theory of electro-rotation corresponding to the strong electric field. The results are compared with the theoretical predictions from the Quincke theory. The angular velocities at different electric field ratios agree well with theoretical predictions. Furthermore, droplet investigations are performed in distinct conductivity regimes with the electric Reynolds number ranging from 10−2 to 104. The findings reveal that conductivity influences the evolution of diverse droplet shapes in the corresponding regimes through surface charge convection. We observe prolate shapes at very low electric conductivities, while larger conductivities of droplets and suspending media lead to oblate drop shapes. With increasing electrical conductivity of the droplet and the medium, we observe the onset of distinct droplet shapes similar to the existing literature. The mechanism for the onset of different regimes is adequately explained by quantifying surface properties like tangential stress and velocity.
Investigation of the slipstream and the wake flow turbulence kinetic energy budget of high-speed train
Authors: Chen Guang , Wang Kai-Wen , Li Xiao-Bai , Liang Xi-Feng
Published: October 2024

Slipstream, which is caused by the movement of high-speed trains (HSTs) and transported mainly by the outward movement with the downstream development of the pair counter-rotating vortex, has been a threat to the railway facilities and staff near the line. Although the cause and distribution of slipstreams have been widely studied, the mechanism behind slipstreams needs to be further clarified. The detailed turbulence kinetic energy (TKE) budget analysis including the advection term, production term, and turbulence transport term in the wake region of the train is conducted to reveal the formation and distribution of the slipstream. Considering the fact that the HSTs can operate in the open air and inside the tunnel, this paper compares and analyzes the effect of the blocking ratio induced by the tunnel wall on the TKE budget, as well as the aerodynamic force, slipstream, and flow structure around trains. The findings demonstrate that the tunnel wall's blocking effect does not modify the vortex-shedding process or the flow pattern around the train. However, the time-averaged (U¯slipstream) and standard deviation (σslipstream) of the slipstream in the near wake are increased because of the tunnel wall blocking effect. Meanwhile, the displacement boundary layer and the momentum boundary layer are hindered by the tunnel wall-blocking effect. The analysis of the TKE budget in the wake of HSTs shows that the total advection is primarily driven by the streamwise velocity (Axk). When the distribution Axk intersects with the measuring position on both sides of the track, the maximum value U¯slipstream and its corresponding position are determined. The turbulence transport term Tu,yk dominates the total transport of TKE and the distribution of σslipstream. The Tu,yk transfers energy from the pair of counter-rotating vortex inward into the wake region and outward away from the vortex core when the turbulent wake interacts with the undisturbed mean flow.
Enhancing photovoltaic performance of organic solar cells by embedding plasmonic Ag nanocuboid array in the active layer
Authors: Zhou Jinxin , Gao Fuhao , Xu Haitao , Long Yongbing
Published: October 2024

This paper presents a method to enhance the light absorption and power conversion efficiency of organic solar cells (OSCs) by embedding a plasmonic Ag nanocuboid array into the active layer. Numerical simulations based on the finite-difference time-domain method are conducted to compare the enhancement of short circuit current density (Jsc) caused by the Ag nanocuboid array with other types of plasmonic nanostructures such as nanocubes, nanospheres, nanorods, and nanocylinders. It is demonstrated that the nanocuboid array can lead to an enhancement of 25.5% in Jsc, much higher than that of other nanostructure arrays. Analyses of the photoelectric field and light absorption enhancement show that the enhancement in Jsc primarily results from the combined effects of localized surface plasmon resonance (LSPR) and optical interference within the devices. It is also revealed that the optical interference can improve or weaken the absorption-enhancing ability of the LSPR mode, which depends on the spectral position of the LSPR mode and the spatial position of the Ag nanocuboids in the optical electric field. Finally, we investigate the effects of light polarization and nanostructure size on Jsc enhancement of the OSC devices. The findings in the paper provide theoretical support for designing OSCs with thinner active layers and superior absorption performance.
Extracting dynamical maps of non-Markovian open quantum systems
Authors: Strachan David J. , Purkayastha Archak , Clark Stephen R.
Published: October 2024

The most general description of quantum evolution up to a time τ is a completely positive tracing preserving map known as a dynamical mapΛ̂(τ). Here, we consider Λ̂(τ) arising from suddenly coupling a system to one or more thermal baths with a strength that is neither weak nor strong. Given no clear separation of characteristic system/bath time scales, Λ̂(τ) is generically expected to be non-Markovian; however, we do assume the ensuing dynamics has a unique steady state, implying the baths possess a finite memory time τm. By combining several techniques within a tensor network framework, we directly and accurately extract Λ̂(τ) for a small number of interacting fermionic modes coupled to infinite non-interacting Fermi baths. First, we use an orthogonal polynomial mapping and thermofield doubling to arrive at a purified chain representation of the baths whose length directly equates to a time over which the dynamics of the infinite baths is faithfully captured. Second, we employ the Choi–Jamiolkowski isomorphism so that Λ̂(τ) can be fully reconstructed from a single pure state calculation of the unitary dynamics of the system, bath and their replica auxiliary modes up to time τ. From Λ̂(τ), we also compute the time local propagator L̂(τ). By examining the convergence with τ of the instantaneous fixed points of these objects, we establish their respective memory times τmΛ and τmL. Beyond these times, the propagator L̂(τ) and dynamical map Λ̂(τ) accurately describe all the subsequent long-time relaxation dynamics up to stationarity. These timescales form a hierarchy τmL≤τmΛ≤τre, where τre is a characteristic relaxation time of the dynamics. Our numerical examples of interacting spinless Fermi chains and the single impurity Anderson model demonstrate regimes where τre ≫ τm, where our approach can offer a significant speedup in determining the stationary state compared to directly simulating the long-time limit. Our results also show that having access to Λ̂(τ) affords a number of insightful analyses of the open system thus far not commonly exploited.
Robust biomimetic strain sensor based on butterfly wing-derived skeleton structure
Authors: Teng Fu-Rui , Tan Si-Chen , Fang Jia-Bin , Zi Tao-Qing , Wu Di , Li Ai-Dong
Published: October 2024

A biomimetic strain sensor was designed and constructed based on Ir nanoparticles-modified multi-wall carbon nanotubes (Ir NPs@MWCNTs) and parallel Pt layer/dragon skin with carbonized butterfly wing patterns. This sensor exhibits high gauge factor (∼515.4), extensive tensile range (0%–96%), and swift response (∼300 ms), especially remarkable stability up to 60 000 cycles. The work mechanism has been proposed based on the experimental test and finite-element method. Some important applications such as human motion and micro-expression recognition have been confirmed using 3 × 3 flexible biomimetic sensor array.
Effect of magnetic field on deceleration of ion beam in plasma with ion-acoustic turbulence
Authors: Shelkovoy A. A. , Uryupin S. A.
Published: October 2024

The deceleration of a monoenergetic rarefied ion beam in nonisothermal plasma in a constant magnetic field has been studied. It is shown how ion-acoustic turbulence generated by a current along the magnetic field leads to an effective decrease in the velocity of ions moving with a speed higher than the speed of ion sound. When an ion beam is injected into plasma across the magnetic field, the trajectory of the ions has the form of a contracting spiral elongated along the magnetic field. The deceleration occurs due to the Cherenkov interaction of ions with ion-acoustic waves and stops when the ion velocity decreases to the speed of ion sound. The braking lengths and the beam velocity components, which are set at the moment of stopping braking, are found. After the end of deceleration, the ions move with constant velocity in a spiral along the magnetic field.
FMO-LC-TDDFTB method for excited states of large molecular assemblies in the strong light-matter coupling regime
Authors: Einsele Richard , Philipp Luca Nils , Mitrić Roland
Published: October 2024

We present a new methodology to calculate the strong light-matter coupling between photonic modes in microcavities and large molecular aggregates that consist of hundreds of molecular fragments. To this end, we combine our fragment molecular orbital long-range corrected time-dependent density functional tight-binding methodology with a generalized Tavis–Cummings Hamiltonian. We employ an excitonic Hamiltonian, which is built from a quasi-diabatic basis that is constructed from locally excited and charge-transfer states of all molecular fragments. To calculate polaritonic states, we extend our quasi-diabatic basis to include photonic states of a microcavity and derive and implement the couplings between the locally excited states and the cavity states and built a Tavis–Cummings Hamiltonian that incorporates the intermolecular excitonic couplings. Subsequently, we demonstrate the capability of our methodology by simulating the influence of the electric field polarization on the polaritonic spectra for a tetracene aggregate of 125 monomers. Furthermore, we investigate the dependence of the splitting of the upper and lower polaritonic branches on the system size by comparing the spectra of five different tetracene clusters. In addition, we investigate the polariton dispersion of a large tetracene aggregate for electric field polarizations in the x, y, and z directions. Our new methodology can facilitate the future study of exciton dynamics in complex molecular systems, which consist of up to hundreds of molecules that are influenced by strong light–matter coupling to microcavities.
Multimode vibrational coupling across the insulator-to-metal transition in 1T-TaS2 in THz cavities
Authors: Jarc Giacomo , Mathengattil Shahla Yasmin , Montanaro Angela , Rigoni Enrico Maria , Dal Zilio Simone , Fausti Daniele
Published: October 2024

The use of optical cavities on resonance with material excitations allows controlling light–matter interaction in both the regimes of weak and strong coupling. We study here the multimode vibrational coupling of low energy phonons in the charge-density-wave material 1T-TaS2 across its insulator-to-metal phase transition. For this purpose, we embed 1T-TaS2 into THz Fabry–Pérot cryogenic cavities tunable in frequency within the spectral range of the vibrational modes of the insulating phase and track the linear response of the coupled phonons across the insulator-to-metal transition. In the low temperature dielectric state, we reveal the signatures of a multimode vibrational strong collective coupling. The observed polariton modes inherit character from all the vibrational resonances as a consequence of the cavity-mediated hybridization. We reveal that the vibrational strong collective coupling is suppressed across the insulator-to-metal transition as a consequence of the phonon-screening induced by the free charges. Our findings emphasize how the response of cavity-coupled vibrations can be modified by the presence of free charges, uncovering a new direction toward the tuning of coherent light–matter interaction in cavity-confined correlated materials.
Atomic cluster expansion interatomic potential for defects and thermodynamics of Cu–W system
Authors: Pan Jiahao , Cheng Huiqun , Yan Gaosheng , Zhang Lei , Yu Wenshan , Shen Shengping
Published: October 2024

The unique properties exhibited in immiscible metals, such as excellent strength, hardness, and radiation-damage tolerance, have stimulated the interest of many researchers. As a typical immiscible metal system, the Cu–W nano-multilayers combine the plasticity of copper and the strength of tungsten, making it a suitable candidate for applications in aerospace, nuclear fusion engineering, and electronic packaging, etc. To understand the atomistic origin of the defects (e.g., vacancies, free surfaces, grain boundaries, and stacking faults and thermodynamical properties), we developed an accurate machine learning interatomic potential for Cu–W based on the atomic cluster expansion (ACE) method. The Cu–W ACE potential can faithfully reproduce the fundamental properties of Cu and W predicted by density functional theory (DFT) calculations. Moreover, the thermodynamical properties, such as the melting point, coefficient of thermal expansion, diffusion coefficient, and equation of the state curve of the Cu–W solid solution, are calculated and compared against DFT and experiments. Monte Carlo molecular dynamics simulations performed with the Cu–W ACE potential predict the experimentally observed phase separation and uphill diffusion phenomena. Our findings not only provide an accurate ACE potential for describing the Cu–W immiscible system but also shed light on understanding the atomistic mechanism during the Cu–W nano-multilayers formation process.
Dynamics of a laser-induced bubble near a cylinder within a confined space
Authors: Shen Junwei , Zhang Shurui , Tang Xiaofeng , Xu Qihang , Zhang Tingting , Liu Wenda , Zhang Yuning , Zhang Yuning
Published: October 2024

The collapse of a laser-induced bubble near a cylinder within a confined space is investigated using high-speed photography and the Kelvin impulse theory. On the basis of an analysis of the liquid flow field and the Kelvin impulse, the effects of bubble–cylinder distance and radius ratio on bubble collapse behavior are investigated. Furthermore, the bubble motion during the first bubble oscillation period is quantitatively explored using the Kelvin impulse theory. The main conclusions of this study are as follows: (1) When the bubble is not restricted by the cylinder, three cases of jets are observed—strong jet, medium jet, and weak jet. When the bubble is restricted by the cylinder, three cases of bubble deformation are observed—fan-shaped collapse, ellipse-shaped collapse, and quasi circular shaped collapse. (2) The cylinder mainly affects the velocity of the surrounding liquid through the term of the point sink, and the bubble–cylinder distance mainly affects the liquid velocity from the bubble. (3) The Kelvin impulse intensity exhibits an exponentially decreasing trend with increasing bubble–cylinder distance, which is in good agreement with the experimentally observed jet velocities.
Shape evolution of fluid deformable surfaces under active geometric forces
Authors: Porrmann Maik , Voigt Axel
Published: October 2024

Models for fluid deformable surfaces provide valid theories to describe the dynamics of thin fluidic sheets of soft materials. To use such models in morphogenesis and development requires to incorporate active forces. We consider active geometric forces that respond to mean curvature gradients. Due to these forces, perturbations in shape can induce tangential flows, which can enhance the perturbation leading to shape instabilities. We numerically explore these shape instabilities and analyze the resulting dynamics of closed surfaces with constant enclosed volume. The numerical approach considers surface finite elements and a semi-implicit time stepping scheme and shows convergence properties, similar to those proven to be optimal for Stokes flow on stationary surfaces.
Interplay mechanisms between hydraulic fractures and natural fractures in various propagation regimes
Authors: Huang Liuke , Liao Xingchuan , Fu Haifeng , Zhang Liehui , Zhao Yulong , Wang Xiaohua , Qian Li
Published: October 2024

It is crucial for the successful development of fractured reservoirs to understand the interaction behavior between hydraulic fractures and natural fractures. This work employed a true-triaxial fracturing experiment using prefabricated samples with natural fractures, along with a three-dimensional (3 D) numerical model, to investigate the interaction mechanisms between hydraulic fractures and preexisting natural fractures. Various influencing factors, including the horizontal stress difference, injection rate, fluid viscosity, and approach angle, are considered. The results reveal three distinct modes of interaction between hydraulic fractures and natural fractures: crossing, deflection, and arrest. As the horizontal stress difference, injection rate, and viscosity increase, the interaction between hydraulic and natural fractures undergoes a gradual shift, evolving from arrest to deflection and ultimately crossing. A smaller approach angle enhances the likelihood of hydraulic fractures being captured by natural fractures. Furthermore, the evaluation criterion of propagating ability is proposed based on the dimensionless value to facilitate the evaluation of the interplay between hydraulic and natural fractures. The interaction behavior diagrams between hydraulic fracture and natural fracture in different regimes is established. It shows that the fracture penetration capacity gradually increases from toughness-dominated regime to viscous-dominated regime, as evidenced by the phased arrangement of arrest, deflection, and crossing in their interaction with natural fractures. When the tensile strength and cohesion of natural fractures is high, hydraulic fractures tend to pass through directly, while conversely, they are easily arrested by natural fractures. The research findings can offer valuable insights for optimizing the fracturing in unconventional reservoirs with developed natural fractures.
Dynamics of a droplet on the surfactant-infested free surface of another liquid
Authors: Panday Prashant Narayan , Darshan Shreyansh , Bandopadhyay Aditya , Das Prasanta Kumar
Published: October 2024

The dynamics of liquid droplets surfing over the surfactant-infested free surface of another liquid have been explored experimentally. We analyze the motion of oil droplets that has been initiated through the creation of a surface tension gradient resulting from the deposition of a drop of surfactant at the water surface contained in the petri dish. The experiments reveal that the location of surfactant deposition with respect to the droplet position influences its motion. Due to the presence of a surface tension gradient, the footprint area of the droplet reduces and its shape changes. We have studied the temporal variation in the velocity (|vx|) of the droplets in relation to their proximity to a wall. Based on the evolution of droplet shape and change in droplet velocity, the drop dynamics can be experimentally divided into four distinct zones. Results indicate that in zone-1, |vx| grows with t as |vx|≈tn, where n is between 0.8 and 1.0. The scaling argument shows that in this zone, the surface tension force dominates the drag force, and thereby, |vx| of the droplets increases linearly with t expressed as |vx|∝t. The experimental investigation and the scaling law exhibit a reasonable agreement. In zone-2, |vx| remains more or less constant, as it is postulated that the surface tension force balances the drag force. In zone-3, a decrease in surface tension force results in a deceleration of the droplets. In zone-4, the deceleration becomes more prominent as the droplet approaches the petri dish wall.
Analytical solutions for the magneto-fluid–structure interaction dynamics with two degrees of freedom
Authors: Fu Jing-Yu , Ni Ming-Jiu , Zhang Nian-Mei
Published: October 2024

The study focuses on the interaction between fluid and structure under an external magnetic field. The system consists of two rigid cylinders, with the inner cylinder having either translating vibrating or rotating vibrating freedoms. The solutions describing the coupling characteristics among the multi-physics fields are derived, using the zero- and first-order complex modified Bessel functions. The study analyzes the effects of the magnetic field on flow fields, electrical potential distributions, and cylinder vibration characteristics. It also reveals the physical mechanisms behind the coupled effects among fluid flow, cylinder vibration, and the electrical potential field. The study finds that for initial tangential rotating vibration, the magnetic field can stabilize both the flow field and cylinder vibration. Additionally, an increasing magnetic field can transform the cylinder vibration from underdamping to overdamping. On the other hand, for initial translating vibration, the magnetic field can induce instability in the system, with larger magnetic fields leading to divergent, negatively damped vibration. The critical magnetic fields for both rotating and translating vibrations are determined using phase maps. The study also shows that the combined effects of rotating and translating vibrations lead to asymmetry in the flow field. While translating vibration plays a dominant role in the combined vibration, it nonlinearly and non-monotonously influences the system dynamics.
Charged-particle transport in high energy density plasmas
Authors: Hansen Stephanie B. , Stanek Lucas J. , Haines Brian M. , Hu S. X. , Knapp Patrick F. , Murillo Michael S. , Stanton Liam G. , Whitley Heather D.
Published: October 2024

This Special Topic Collection grew out of two gatherings of researchers active in the high energy density (HED) physics community: a mini-conference on charged-particle transport in HED plasma held during the 64th annual meeting of the American Physical Society's Division of Plasma Physics (Spokane, WA, November 2022) and a dedicated charged-particle transport coefficient code comparison workshop (Livermore, CA, July 2023). These gatherings provided opportunities for theoretical, computational, and experimental researchers to discuss the state of the field, including current capabilities and methods, needs of hydrodynamic simulations, and frontiers for future research. This special issue collects a total of 13 research and review articles on charged-particle transport in HED plasmas.
More than ‘ignorant bushbaby bullshit’
Authors: Adam Naomi
Published: October 2024

According to the social psychologists R. D. Laing, H. Phillipson and A. R. Lee, we human beings are constantly
speculating about the view that others have upon us, thereby forming a metaperspective (Laing
et al. 1966). Yet despite the fact that literature is grounded in some of the most fundamental and
general structures of human cognitive experience (Gavins and Steen 2003: 2), proving a
rich seam to mine for metaperspectives, the concept has not yet been explored in a literary context. Accordingly, this paper
adopts an interdisciplinary approach to investigate metaperspectives within fiction for the first time. Introduced is my coinage
of the racialised metaperspective, denoting a sub-type concerned with colour, culture, and/or ethnicity. Taking
as my literary case study Marlon James’ A Brief History of Seven Killings (2014), I demonstrate that the
racialised metaperspective both contributes to the depiction of a specific social milieu within a text, and serves a
characterising function.
Code-switching in South Asian English CMC
Authors: Shakir Muhammad , Deuber Dagmar
Published: October 2024

This paper analyses the use of indigenous language elements including code-switching in two contrasting genres,
i.e. group chats and Twitter memes along with tweets, in the English communication of South Asian (Bangladeshi, Indian, Pakistani,
and Sri Lankan) internet users. The results from group chats show that one of the most common lexical indigenous elements are
tags, for example, address forms like yaar, machan, and da which all can be translated to
English as ‘dude’ or ‘buddy’. The analysis of Twitter memes along with tweets shows that despite the tweet text being in English,
the South Asian users tend to employ memes with indigenous text more often as compared to English memes for political satire.
Overall, the study finds that code-switching and indigenous resources are used to create a sense of localness in English
communication, whether it is group chats or Twitter memes and tweets.
Crazy literature
Authors: Liu Shiyu , Chen Rong , Liu Fengguang
Published: October 2024

In this paper, we investigate crazy literature, a newly emerged genre on Chinese Internet in which posters portray
themselves as being mentally instable or, simply, insane. Based on data collected from the Internet and findings from a survey of
college students, we argue that the image created by crazy literature is best captured by the notion of mock self-impoliteness.
That is, although the image of insanity is damaging to the self-face of the poster, the impolite self-image is a persona, not the
real image, motivated by transactional effectiveness. In addition, crazy literature helps the blogger to appear humorous, to
express their helplessness in vulnerable situations, and to gain a sense of belonging. Our paper, therefore, contributes to the
pragmatics literature by drawing scholars’ attention to a (possibly) hitherto non-existent type of language use, offering an
analysis of the genre that is innovative, and demonstrating a need for investigating Internet pragmatics seriously.
Trade-offs in translation effects
Authors: Pym Anthony , Hu Ke
Published: October 2024

Trade-offs are solutions to translation problems where two or more apparently incompatible values are sought at
the same time. As such, they present an alternative to theories that see translation as operating between two polarities of the
one value. Analysis of three illustrative examples suggests that receivers can activate trade-offs that are quite different from
those envisaged by translators and that different readerships may seek different kinds of trade-offs. The resulting instability
gives rise to problems concerning research methodology. It is proposed that the study of trade-offs is suited to a mixed-methods
approach that starts from receiver-produced data, that allows for more than two values, and that recognizes that not all solutions
are trade-offs. This approach can also identify situations where one kind of trade-off leads to another, creating chains of value
transformation that are informed by translation history.
Optoelectronic, thermoelectric, and elastic properties of Cu6PSe5X (X = Br, I) argyrodites using density functional theory
Authors: Zaman Tahir , Ullah Mohib , Chaudhry Aijaz Rasool , Ibrar Muhammad , Jehangir Muhammad Awais , Saeed Muhammad , Haneef Muhammad , Murtaza G
Published: October 2024

Cu6PSe5X (X = Br, I) argyrodites’ structural, optoelectronic, elastic, anisotropic, and thermal properties are examined using the method of ab initio through the density functional theory. There is a significant match found between the calculated ground state structural characteristics and the available data. Based on the Birch-Murnaghan fit curve for optimization, it is found that both compounds achieve ground state. The energy bandgap of Cu6PSe5Br is 0.606 eV (indirect), while Cu6PSe5I has a band gap of 0.697 eV (direct) according to the mBJ-functional. They appear to be promising prospects for high frequency applications since the UV area contains the most notable absorption peak. The BoltzTrap package, which is incorporated into WIEN2K, has been used to determine the thermoelectric properties. Cu6PSe5Br thermal conductivity reaches a maximum of 4.6 × 1014 (W/mKs) when the temperature rises to 1000 K, whereas Cu6PSe5I has a maximum value of 5.24 × 1014 (W/mKs). At room temperature, the ZT values for Cu6PSe5Br and Cu6PSe5I are 0.803 and 0.972, respectively. The elastic constants show that the materials are mechanically stable. The estimated Poisson ratio, which ranges from 0.264 for the Br-based to 0.252 for the I-based, indicates that bonding has a significant ionic character. Compared to Cu6PSe5I, Cu6PSe5Br has a greater melting temperature. Since these materials have appropriate energy bandgaps, they can be used in several optoelectronic devices.
Energy-efficient design and CNFET implementation of GDI-based ternary prefix adders
Authors: Shanmugam Kavitha , Chandrasekaran Kumar , Manoharan Premkumar , Ravichandran Sowmya
Published: October 2024

Ternary adders have produced more benefits compared to binary adders i.e., the ternary adder occupies less amount of area as well as produces less interconnect complexity. However, the CMOS implementation of the ternary adders failed to perform the process when the channel length was taken as 32 nm. At 32 nm technology, the CMOS transistors exhibit undesired effects such as Short Channel Effects (SCEs), mobility degradation, high leakage current, etc. Multi-gate devices are preferred to overcome these issues. Carbon Nano-tube Field Effect Transistors (CNFETs) are one of the technologies to work efficiently when the channel length is 32 nm. In this paper, CNFET-based ternary prefix adders are designed. Power consumption is the most critical requirement for the VLSI system, as it enhances energy efficiency and reduces heat dissipation. One way to achieve this power reduction is by minimizing the number of transistors employed in the adder circuits. This study employed a reduction technique known as Gate Diffusion Input (GDI) logic included in the proposed prefix adder design. The overall experimental investigation is done with the help of the HSPICE supporting platform. The proposed adder improved by reducing the power by up to 83%, energy by up to 83%, current by up to 78%, and delay by up to 96%. Finally, the Power Delay product (PDP) was also reduced by 84% compared to existing ternary adders. The proposed design proves to be highly effective in implementing the neuron structure, with the corresponding parameters thoroughly analysed and well-documented in this study.
Modulation of shape memory properties of trans-polyisoprene by sulfur
Authors: Zhang Tao , Zhao Wenli , Cao Zerong , Liang Yurong
Published: October 2024

In this paper, TPI/S composites were prepared by a simple physical melt blending method, and the composites were hot-pressed and molded using a vulcanization system. The effect of cross-linking on the vulcanization properties, mechanical properties, crystalline properties, and shape memory properties of trans-1-4 polyisoprene (TPI) was investigated by varying the amount of sulfur (S). It was shown that with the increase of sulfur dosage, both TPI scorch time and orthoclave time were shortened and the mechanical properties decreased; The melting peak area and melting temperature of the crystalline region of TPI decreased with the increase of sulfur content, and the cross-linking density increased while the crystallinity tended to decrease and the heat resistance deteriorated; In addition, with the increase of sulfur content, the shape return rate of TPI/S composites was increasing and the shape fixation rate was decreasing. When the TPI/S composites were used as shape memory materials, the sulfur dosage of 1 phr had the best shape memory performance, at which time the shape fixation rate of the composites reached 96.9% and the shape recovery rate reached 86.2%. When the sulfur content was elevated to 2 phr, the shape memory fixation rate was significantly decreased, indicating that the shape memory properties were severely compromised. This study reveals that the quantity of sulfur exerts a significant influence on the application of TPI/S composites. An appropriate amount of sulfur can facilitate the preparation of thermoplastic elastomers for utilization in shape memory materials. Nevertheless, an excessive amount of sulfur will substantially enhance the internal cross-linked structure of the composite and deteriorate the shape memory performance.
Hybrid deep learning model for vegetable price forecasting based on principal component analysis and attention mechanism
Authors: Chen Xinzhi , Cai Chengzhi , He Xinyi , Mei Duan
Published: October 2024

With the aim of enhancing the accuracy of current models for forecasting vegetable prices and improving market structures, this study focuses on the prices of bell peppers at the Nanhuanqiao Market in Suzhou. In this paper, we propose a hybrid Convolutional Neural Network (CNN) and Gated Recurrent Unit (GRU) model for vegetable price forecasting based on Principal Component Analysis (PCA) and Attention Mechanism (ATT). Initially, we utilized the Pearson correlation coefficient to filter out the factors impacting prices. Then, we applied PCA to reduce dimensionality, extracting key price features. Next, we captured local sequence patterns with CNN, while handling time-series features with GRU. Finally, these outputs were integrated via ATT to generate the final prediction. Our results indicate that the hybrid CNN-GRU model, enhanced by PCA and ATT, achieved a Root Mean Square Error (RMSE) as low as 0.1642. This performance is 11.11%, 11.11%, and 15.79% better than that of the PCA-CNN, PCA-GRU, and CNN-GRU-ATT models, respectively. Furthermore, in order to prove the effectiveness of our proposed model, the proposed model is compared with the state-of-the-art models and classical machine learning algorithms under the same dataset, the results indicate that our proposed hybrid deep learning model based on PCA and ATT shows the best performance. Consequently, our model offers a valuable reference for vegetable price prediction.