bluuebunny/crossref_metadata_2025 huggingface dataset:
Regularity for 3D inhomogeneous incompressible MHD equations with vacuum
Authors: Kim Jae-Myoung
Published: November 2022

In this paper, we consider the conditional regularity for 3D inhomogeneous incompressible magnetohydrodynamic equations in Vishik spaces and give a regularity criterion of weak solutions in terms of a gradient velocity vector.
Helicity exchange and symmetry breaking of in-plane phonon scattering of h-BN probed by polarized Raman spectroscopy
Authors: Chien Shih-Po , Chang Yu-Chen , Simbulan Kristan Bryan , Saha Shantanu , Chiang Yu-Fan , Saroj Rajendra K. , Yi Gyu-Chul , Arafin Shamsul , Lu Ting-Hua , Lan Yann-Wen
Published: November 2022

Due to its atomic thickness and insulating nature, hexagonal boron nitride (h-BN) is considered to be one of the most promising substrates and gate insulating materials for two-dimensional electronic devices. In this study, polarized Raman spectroscopy was employed to uncover the effects of polarized incident light on the optical properties of h-BN phonon modes. Our measured polarization-resolved Raman spectra indicate that the symmetrical nature and the broken symmetry of degenerate phonon modes from h-BN are induced by linearly and elliptically polarized light, respectively. Moreover, a helicity exchange was observed between the excitation of circularly polarized light and the resulting opposite circular polarization of scattered light from h-BN. The measured phenomena were modeled on the basis of Raman tensors and Jones calculus to eventually calculate the amplitude coefficients of two orthogonal in-plane phonon modes. Hence, our experimental study provides a holistic understanding of the vibrational modes in h-BN, which is expected to enhance the knowledge of physical mechanisms such as heat capacity and thermal and electrical conductivities of this layered material.
Impact of the electric field on isotropic and anisotropic spin Hamiltonian parameters
Authors: Pradines Barthélémy , Cahier Benjamin , Suaud Nicolas , Guihéry Nathalie
Published: November 2022

One may obviously think that the best way to control magnetic properties relies on using a magnetic field. However, it is not convenient to focus a magnetic field on a small object, whereas it is much easier to do so with an electric field. Magnetoelectric coupling allows one to control the magnetization with the electric field and the polarization with the magnetic field and could therefore provide a solution to this problem. This paper aims at quantifying the impact of the electric field on both the isotropic magnetic exchange and the Dzyaloshinskii–Moriya interaction in the case of a binuclear system of S = 1/2 spins. This study follows previous studies that showed that very high Dzyaloshinskii–Moriya interaction, i.e., the antisymmetric exchange, can be generated when close to first order spin orbit coupling. We will, therefore, explore this regime in a model Cu(II) complex that exhibits a quasi-degeneracy of the dx2−y2 and dxy orbitals. This situation is indeed the one that allows us to obtain the largest spin orbit couplings in transition metal complexes. We will show that both the magnetic exchange and the Dzyaloshinskii–Moriya interaction are very sensitive to the electric field and that it would therefore be possible to modulate and control magnetic properties by the electric field. Finally, rationalizations of the obtained results will be proposed.
Multiscale simulation of shock to detonation in condensed phase explosives
Authors: Lee Sangyup , Fahrenthold Eric P.
Published: November 2022

Multiscale methods that are systematic, computationally efficient, and applicable to a wide range of materials are needed to complement experimental research in the development of improved explosives and propellants. Recent research has developed a new unified discrete Hamiltonian approach to multiscale simulation of reacting shock physics using a nonholonomic modeling methodology. The method incorporates the first extension of hybrid particle-element methods to reacting media, the first computational development of an ignition and growth model for condensed phase explosives, and the first use of temperature-parameterized recombination reactions, allowing reacting molecular dynamics derived chemical kinetics to be directly incorporated into the macroscale thermomechanical model. The formulation includes general material and geometric nonlinearities and both Lagrangian and Eulerian reference frames and has been validated in multiscale simulations of shock to detonation in two nitramine explosives.
Hydrodynamic performance and energy absorption of multiple spherical absorbers along a straight coast
Authors: Li Ai-jun , Liu Yong
Published: November 2022

The development and utilization of wave energy have great potentiality to alleviate the urgent problem of global energy shortage. Spherical bodies can be used as point absorbers to extract wave energy, and much attention has been paid to the performance of spherical absorbers in an open water domain. This study focuses on the hydrodynamic performance and energy absorption of multiple spherical absorbers in front of a straight coast. The coast is assumed to be a fully reflecting vertical wall, and all the absorbers are restricted to only heave motion. An analytical solution based on linear potential flow theory is developed for the problem of wave diffraction and radiation by multiple absorbers. In the solution procedure, the hydrodynamic problem is transformed into an equivalent problem in an open water domain by applying the image principle. The velocity potential of the fluid motion is solved using the method of multipole expansions combined with the shift of local spherical coordinate systems. Then, the wave excitation force, added mass coefficient, radiation damping coefficient, and energy extraction performance of the absorbers are calculated. Case studies are presented to analyze the effects of the coastal reflection and hydrodynamic interaction among absorbers on the energy extraction performance of the wave energy converter (WEC) system. The effects of wave frequency, incident angle, spacing between the absorber and coast, submergence depth, absorber number, and plane layout are also clarified. The results suggest that the energy extraction performance of an isolated absorber is significantly improved when the motions of the waves and absorber are in resonance, and the coastal reflection can enhance the overall energy extraction performance for a WEC system with multiple absorbers. In addition, when the number of absorbers increases, the effects of the coastal reflection and hydrodynamic interaction become more complicated.
Numerical study on wave configuration of wedge-induced oblique detonation wave: Reactive boundary layer effect
Authors: Yang Li , Yue Lianjie , Yu Dehai , Chen Zheng
Published: November 2022

A numerical simulation solving the Reynolds-averaged Navier–Stokes equation is presented to investigate the initiation and evolution of the wedge-induced oblique detonation wave (ODW) with emphasis on the effects of the burning boundary layer. The nondimensional activation energy (Ea) is selected as the bifurcate parameter, which varies from 30 to 50. The largest induction ignition length behind the oblique shock/detonation wave is shown to be proportional to the Ea. The initiation of ODW can be attributed to the collision and diffraction of reactive waves. The wave configuration, a series of compression waves (or shock wave), is observed at the conjunction point of the burning boundary layer and combustion wave, which intensifies the pressure jump as increasing the Ea. The polar line analysis demonstrates that the pressure jump triggers the transition from regular reflection to Mach reflection near triple-point. The oscillations of the ODW wave structures, for example, the triple-point and Mach stem, can be attributed to the Rayleigh–Taylor instabilities developed on the reaction front of the boundary layer, which shall be appropriately suppressed to remain the steadiness of the ODW and flow configuration.
Open quantum dynamics of strongly coupled oscillators with multi-configuration time-dependent Hartree propagation and Markovian quantum jumps
Authors: Triana Johan F. , Herrera Felipe
Published: November 2022

Modeling the non-equilibrium dissipative dynamics of strongly interacting quantized degrees of freedom is a fundamental problem in several branches of physics and chemistry. We implement a quantum state trajectory scheme for solving Lindblad quantum master equations that describe coherent and dissipative processes for a set of strongly coupled quantized oscillators. The scheme involves a sequence of stochastic quantum jumps with transition probabilities determined by the system state and the system-reservoir dynamics. Between consecutive jumps, the wave function is propagated in a coordinate space using the multi-configuration time-dependent Hartree method. We compare this hybrid propagation methodology with exact Liouville space solutions for physical systems of interest in cavity quantum electrodynamics, demonstrating accurate results for experimentally relevant observables using a tractable number of quantum trajectories. We show the potential for solving the dissipative dynamics of finite size arrays of strongly interacting quantized oscillators with high excitation densities, a scenario that is challenging for conventional density matrix propagators due to the large dimensionality of the underlying Hilbert space.
Spontaneous emission modulation in biaxial hyperbolic van der Waals material
Authors: Liu Haotuo , Hu Yang , Ai Qing , Xie Ming , Wu Xiaohu
Published: November 2022

As a natural van der Waals crystal, α-MoO3 has excellent in-plane hyperbolic properties and essential nanophotonics applications. However, its tunable properties are generally neglected. Here, we achieve effective modulation of spontaneous emission (SE) from a single-layer flat plate by changing the crystal directions. Numerical results and theoretical analysis show that α-MoO3 exhibits good tunability when the crystal directions of α-MoO3 are different in y–z or x–y planes. A modulation factor of more than three orders of magnitude is obtained at 634 cm−1. This phenomenon is caused by the excitation of hyperbolic phonon polaritons in α-MoO3 at specific bands. However, when the crystal directions of α-MoO3 are different in the x–z plane, the SE of the material exhibits strong angle independence. Additionally, for the semi-infinite α-MoO3 flat structure, we determine the distribution of the modulation factor of SE using the wavenumber and rotation angle. Finally, we extend the calculation results from semi-infinite media to finite thickness films. We obtain the general evolution law of the peak angle of the modulation factor with thickness, increasing the modulation factor to approximately 2000, which exceeds the maximum modulation factor observed in previous works by 48 times. We believe this work could guide the SE modulation of anisotropic materials and benefit the field of micro-/nano-lasers and quantum computing.
Special roles of two-dimensional octahedral frameworks in photodynamics of Cs3Bi2Br9 nanoplatelets: Electron and lattice-wave localization
Authors: Wu Huaxin , Liu Wenjie , Ma Wenjie , Liang Tianyuan , Liu Xiaoyu , Fan Jiyang
Published: November 2022

The low-dimensional cesium bismuth halides are intriguing wide-bandgap semiconductors with fruitful photophysics. However, their photodynamics is rather intricate and remains debated. We study the optical properties of the Cs3Bi2Br9 nanoplatelets (NPLs) by using the combined experimental and first-principles calculation methods. The results indicate that the exhibited dominant blue emission band and weak green band arise from two kinds of shallow color centers. The Cs3Bi2Br9 NPLs exhibit Raman active and inactive vibrational modes that are separately ascribed to the localized lattice waves propagating along the edges and interiors of the quantum well-like bromide–bismuth octahedral frameworks in Cs3Bi2Br9. These findings improve our understanding of the unique photodynamics of these multiple quantum well-like semiconductor nanocrystals.
Estimating the concentration of chiral media with bright squeezed light
Authors: Belsley Alexandre , Matthews Jonathan C. F.
Published: November 2022

The concentration of a chiral solution is a key parameter in many scientific fields and industrial processes. This parameter can be estimated to high precision by exploiting circular birefringence or circular dichroism present in optically active media. Using the quantum Fisher information formalism, we quantify the performance of Gaussian probes in estimating the concentration of chiral analytes. We find that bright-polarization squeezed state probes provide a quantum advantage over equally bright classical strategies that scales exponentially with the squeezing factor for a circularly birefringent sample. Four-fold precision enhancement is achievable using state-of-the-art squeezing levels and intensity measurements.
Cathodoluminescence monitoring of quantum emitter activation in hexagonal boron nitride
Authors: Roux Sébastien , Fournier Clarisse , Watanabe Kenji , Taniguchi Takashi , Hermier Jean-Pierre , Barjon Julien , Delteil Aymeric
Published: November 2022

The ability to locally activate or generate quantum emitters in two-dimensional materials is of major interest for the realization of integrated quantum photonic devices. In particular, hexagonal boron nitride (hBN) has recently been shown to allow a variety of techniques for obtaining quantum emitters at desired locations. Here, we use cathodoluminescence (CL) to monitor in situ the local activation of color centers by an electron beam in hBN. We observe that the CL signal saturates at a given surface dose, independently of the electron current density. Based on photoluminescence and photon correlations, we show that the number of photoactive color centers is proportional to the CL signal, and we estimate the maximum density of quantum emitters that can be generated by our technique. Our results provide insight about the activation mechanism and could help to optimize the controlled generation of single photon sources in hexagonal boron nitride.
Investigation on the lubrication characteristics of low-viscosity lubricated micro-grooved bearings considering turbulence and misalignment
Authors: Li Peng , Shi Zhanqun , Zhang Hao , Fang Liqing , Gu Fengshou , Zhen Dong , Feng Guojin
Published: November 2022

This paper numerically investigates the effect of turbulence and journal misalignment on the lubrication characteristics of micro-grooved bearings with low-viscosity lubricant. The generalized average Reynolds equation satisfying the mass conservation cavitation algorithm is developed by integrating the average flow model proposed by Patir and Cheng, the Ng–Pan turbulent model, and the P-Θ model proposed by Elrod and Adams. With this model, the finite difference method is used in the numerical procedure. Moreover, the mathematical models of micro-grooves with different bottom shapes, that is, rectangle, isosceles triangle, left triangle, and right triangle, are given. The validity of the proposed model is verified by the comparisons with the published literature. Based on numerical simulation, the minimum film thickness, eccentricity ratio, attitude angle, maximum film pressure, friction torque, misalignment moment, film thickness, and pressure distributions under different external loads, rotational speeds, radial clearances, misalignment angles, and micro-groove parameters between models with and without turbulence and misalignment are comparatively analyzed. The numerical results reveal that turbulence may occur under heavy external load, high rotational speed, and large radius clearance. Concurrently, turbulence increases the minimum fluid film thickness and attitude angle, decreases the eccentricity ratio and friction torque, and enhances the bearing capacity. Furthermore, the larger misalignment angle results in the smaller minimum film thickness, eccentricity ratio and attitude angle, and the larger maximum film pressure, misalignment moment, and axial tilt of film pressure. Numerical simulations can provide theoretical guidance for the optimization of the geometrical parameters of micro-grooved bearings.
Time-reversed laser absorbs nearly all light
Authors: Hill Heather M.
Published: November 2022

A simple design overcomes a substantial limitation on potential applications for coherent perfect absorbers.
Lexical blending in terms of cognitive modeling
Authors: Peña-Cervel María Sandra
Published: November 2022

This corpus-based proposal provides a
fine-grained study of lexical blending in the English language in
terms of cognitive modeling. Blending as a word-formation process
has gained growing popularity in recent years either to fill certain
lexical/conceptual gaps or simply to endow language with creativity.
Blended words are defined as combinations of two or more lexemes,
one of which at least has been clipped (Bauer, 2003; Plag, 2003). Researchers of different
persuasions have addressed topics like the definition of blends,
their status as part of prosodic morphology, their scaffolding, the
recognizability of the source words making them up, their degree of
entrenchment, their lack of morphological analyzability, their
classification, and the meaning each of the source words contributes
to the resulting blend (Adams,
1973; Algeo,
1977; Bauer,
2003; Kemmer,
2003; Plag,
2003). Our corpus of analysis has been retrieved from the
online Cambridge Dictionary, consists of 715
lexical items, and covers a five-year time span, from 2016 to 2020.
The analysis of our data reveals that the most productive
word-formation process is compounding, followed by blending, which
accounts for 27.83% of our data (199 coinages). We provide evidence
of the regularity of blended words and of their principled nature by
drawing on the latest developments in cognitive modeling (Peña & Ruiz de Mendoza,
2017; Ruiz de
Mendoza, 2020; Ruiz
de Mendoza & Galera, 2014). In this connection, we
offer an in-depth study of parameterization (both metonymic and
non-metonymic), generalization, contrast, resemblance,
strengthening, expansion, and reduction as cognitive operations that
play a fundamental role in the creation and construal of blended
words.
Time-creation in film
Authors: Coëgnarts Maarten
Published: November 2022

This chapter aims to discuss the creation of time in cinema from an embodied cognitive perspective. Drawing on principles of Cognitive linguistics, we first discuss briefly how our ordinary thinking about time is informed by spatial knowledge. Knowing how space shapes temporal thought, we subsequently show how filmmakers may cue this spatio-temporal logic in the direction of two opposing models of time-creation in cinema: one model in which cinematic creativity serves the purpose of optimal narrative clarity, and another model in which creativity resolves around the opposite goal of spatio-temporal ambiguity. We illustrate both models through various case-examples drawn from classical narrative cinema and modern and postmodern art cinema, respectively.
Physical and imaginary landmarks in English time gestures
Authors: Alcaraz Carrión Daniel
Published: November 2022

In this chapter I discuss several creative instances of time co-speech gestures in English obtained from a repository of television news. I argue that, even though time gestures tend to follow certain patterns in their form, speakers may deviate, giving rise to more creative instances with a more complex meaning. The chapter begins with a brief introduction to the relation between speech and gesture, with a focus on temporal cognition, and timelines. Then, I discuss the notion of creativity in gesture research. I analyze five examples of time gestures that fall under three main categories: the ad hoc creation of imaginary timelines, the inclusion of physical items to the time construal and the emotional and pragmatic component of facial gestures.
For a prospective sociology of language
Authors: Querol Puig Ernest
Published: November 2022

The paper begins by defining the term prospective and goes on to analyze the studies that have been carried out “significantly, only in Catalonia” to predict the future of the Catalan language. Firstly, a critical analysis is made of ‘pseudo-prophetic’ studies – which cannot be considered prospective – that are based on an inability to contemplate a monolingual future, a dream that began with the onset of democracy. The second part of the paper deals with studies that, conversely, can be termed prospective and the third part highlights the advantages of prospective studies and suggests that they be used in language sociology, particularly in the areas of planning and language policy in order to both foresee and prevent.
The process of normalising Catalan in the media
Authors: Gifreu Josep , Corominas Maria
Published: November 2022

The aim of this chapter consists of an initial overall approach to the research carried out over the last 40 years on the process of normalising the Catalan Language in the conventional media (press, radio and television) and online. Firstly, it summarizes the research on the relationship between language policies and communication policies related to the processes of normalisation (“status planning”); secondly, the study of the general process of language standardisation in the media, (“corpus planning”); and, thirdly, the study of the processes and scope of implementation of Catalan in the media (extension of use).
From normalisation to sustainability
Authors: Marí Isidor
Published: November 2022

The policies of public authorities on the status of Catalan since the political transition have not been planned in a systematic way, and have evolved under the disinterest and adversity of Spanish and supranational powers, without overcoming the fragmentation of regional governments and the discontinuity of actions. This paper analyses in a broad way the stages and frameworks in which these public policies on the status of Catalan have taken place. Until the end of the eighties, a linguistic normalization approach predominated, focusing on the creation of a legal and institutional framework that would allow the process of linguistic substitution to be reversed. The need for general language planning became apparent at the end of the 1980s and the beginning of the 1990s, but since the end of this last decade, the central idea has been the politics of language. More recently, the changes induced by the process of globalization have led to a perspective focused on linguistic sustainability, which has gained ground in the early 21st century. After the judgment 31/2010 of the Spanish Constitutional Court on the Statute of Autonomy of Catalonia, Spain’s policies have been particularly adverse to Catalan. Without a coordinated action of the Catalan-speaking territories being able to overcome the current subordination, the future of Catalan is uncertain.
Demolinguistics in Catalan-speaking territories
Authors: Torres Joaquim
Published: November 2022

The article starts by explaining the origins of “demolinguistics” and the reasons behind its emergence and goes on to assess how it has stretched to other parts of the world. The paper then goes into further depth on the emergence of this discipline in the Catalan language domain and, in particular, its evolution in this sphere. This evolution is divided into five stages; two of them date back to the past century and the other three date from the 21st century. The paper then outlines the main issues that demolinguistics deals with in the Catalan sphere and, to conclude, it lists a number of key challenges that the discipline faces.
The linguistic transmission of Catalan
Authors: Mas Miralles Antoni , Montoya Abat Brauli
Published: November 2022

This article is divided into three parts. Firstly, the introduction deals with the need to regard transmission, which includes interruption and revernacularisation, as a process that is essential for understanding the sociolinguistic reality of a language. This analysis is based on the theoretical principles of Social Psychology, Sociology and Sociolinguistics. Secondly, there is a brief summary of the studies which have been carried out so far in Catalan on this topic, both from a quantitative and qualitative point of view. And finally, the conclusion outlines some suggestions and proposals, including the need for a specific theoretical-methodological framework and specific terminology, the importance of using this type of combined quantitative and qualitative analysis, and the possibility of redirecting planning towards the recovery of the Catalan language within the family.
Teaching segmentals and suprasegmentals
Authors: Gordon Joshua , Darcy Isabelle
Published: November 2022

This study reports the results of a pronunciation intervention to enhance the comprehensibility, fluency, and accentedness of three groups of second language (L2) learners in an English-as-a-foreign-language (EFL) context. Three groups of first-semester EFL students at a small university in Costa Rica underwent a 10-week pronunciation intervention for segmentals, suprasegmentals, or a combination of both using explicit phonetic and phonological instruction and communicative tasks. Spontaneous-speech samples from a pretest and posttest were presented to L1 speakers of English to be rated for comprehensibility, fluency, and accentedness. The group trained on suprasegmentals significantly improved comprehensibility and fluency, as opposed to the other two groups that did not improve. No groups improved in accentedness. Analyses of participants’ speech production revealed key differences that may have contributed to the perception of comprehensibility and fluency in their speech. Pedagogical implications are discussed for the implementation of explicit pronunciation instruction in intact L2 classes.
Molecular mechanism of claudin-15 strand flexibility: A computational study
Authors: Fuladi Shadi , McGuinness Sarah , Shen Le , Weber Christopher R. , Khalili-Araghi Fatemeh
Published: November 2022

Claudins are one of the major components of tight junctions that play a key role in the formation and maintenance of the epithelial barrier function. Tight junction strands are dynamic and capable of adapting their structure in response to large-scale tissue rearrangement and cellular movement. Here, we present molecular dynamics simulations of claudin-15 strands of up to 225 nm in length in two parallel lipid membranes and characterize their mechanical properties. The persistence length of claudin-15 strands is comparable with those obtained from analyses of freeze-fracture electron microscopy. Our results indicate that lateral flexibility of claudin strands is due to an interplay of three sets of interfacial interaction networks between two antiparallel double rows of claudins in the membranes. In this model, claudins are assembled into interlocking tetrameric ion channels along the strand that slide with respect to each other as the strands curve over submicrometer-length scales. These results suggest a novel molecular mechanism underlying claudin-15 strand flexibility. It also sheds light on intermolecular interactions and their role in maintaining epithelial barrier function.
A reconstituted depolarization-induced Ca2+ release platform for validation of skeletal muscle disease mutations and drug discovery
Authors: Murayama Takashi , Kurebayashi Nagomi , Numaga-Tomita Takuro , Kobayashi Takuya , Okazaki Satoru , Yamashiro Kyosuke , Nakada Tsutomu , Mori Shuichi , Ishida Ryosuke , Kagechika Hiroyuki , Yamada Mitsuhiko , Sakurai Takashi
Published: November 2022

In skeletal muscle excitation–contraction (E–C) coupling, depolarization of the plasma membrane triggers Ca2+ release from the sarcoplasmic reticulum (SR), referred to as depolarization-induced Ca2+ release (DICR). DICR occurs through the type 1 ryanodine receptor (RyR1), which physically interacts with the dihydropyridine receptor Cav1.1 subunit in specific machinery formed with additional essential components including β1a, Stac3 adaptor protein, and junctophilins. Exome sequencing has accelerated the discovery of many novel mutations in genes encoding DICR machinery in various skeletal muscle diseases. However, functional validation is time-consuming because it must be performed in a skeletal muscle environment. In this study, we established a platform of the reconstituted DICR in HEK293 cells. The essential components were effectively transduced into HEK293 cells expressing RyR1 using baculovirus vectors, and Ca2+ release was quantitatively measured with R-CEPIA1er, a fluorescent ER Ca2+ indicator, without contaminant of extracellular Ca2+ influx. In these cells, [K+]-dependent Ca2+ release was triggered by chemical depolarization with the aid of inward rectifying potassium channel, indicating a successful reconstitution of DICR. Using the platform, we evaluated several Cav1.1 mutations that are implicated in malignant hyperthermia and myopathy. We also tested several RyR1 inhibitors; whereas dantrolene and Cpd1 inhibited DICR, procaine had no effect. Furthermore, twitch potentiators such as perchlorate and thiocyanate shifted the voltage dependence of DICR to more negative potentials without affecting Ca2+-induced Ca2+ release. These results well reproduced the findings with the muscle fibers and the cultured myotubes. Since the procedure is simple and reproducible, the reconstituted DICR platform will be highly useful for the validation of mutations and drug discovery for skeletal muscle diseases.
High-order harmonic generation from periodic asymmetric potentials
Authors: Shao Tian-Jiao , Zou Huan-Qing , Zhang Qiu-Lan
Published: November 2022

High-order harmonic generation (HHG) from periodic asymmetric potentials is investigated by solving the real-space time-dependent Schrödinger equations and semi-conductor Bloch equations. Our results show that the periodic asymmetric potential will cause asymmetric excitation and HHG dynamics in the time domain, leading to the signal of even order harmonics. From the k-space perspective, a k-dependent transition dipole moment phase reflects the real-space asymmetry and causes the symmetry breaking of excitation and HHG dynamics. We also illustrate that the dephasing effect competes with the asymmetry of interband HHG dynamics. Large amplitude of the driving field is beneficial for observing the symmetry breaking of interband HHG. However, it is found symmetry breaking of intraband HHG dynamics is less influenced by dephasing. Moreover, a carrier-envelope phase controlled driving laser field can be utilized as an isolated attosecond pulse gating mechanism for HHG from the periodic asymmetric potentials.
Numerical simulation on the characteristics of a micro-hollow cathode discharge with external surface of the cathode covered by a dielectric layer
Authors: Jia Pengying , Ran Junxia , Wu Jiacun , Wang Dongdong , Wu Kaiyue , He Xingran , Li Xuechen
Published: November 2022

Being able to generate a plasma denser than that in the usual micro-hollow cathode discharge (MHCD) device, a MHCD with the cathode outer surface covered by a dielectric layer has been numerically simulated in atmospheric pressure helium with a two-dimensional fluid model in this paper. Results indicate that before reaching a steady state, the covered MHCD sequentially undergoes three phases. In the initial phase, a strong discharge and a weak discharge appear in the vicinities of the cathode and the anode, respectively. Then, a positive streamer propagates along the axis from the anode to the cathode. After that, the entire gap between the two electrodes is filled with discharges. In addition, the evolution of averaged densities is given for various species. Moreover, voltage and current curves are compared for the covered and uncovered MHCDs in the steady state. As expected, the covered MHCD has an averaged electron density higher than that of the uncovered MHCD in the steady state. These results are helpful in generating an atmospheric pressure plasma with high electron density, which is important for the extensive applications of MHCD.
Landau levels and snake states of pseudo-spin-1 Dirac-like electrons in gapped Lieb lattices
Authors: Jakubský V , Zelaya K
Published: November 2022

This work reports the three-band structure associated with a Lieb lattice with arbitrary nearest and next-nearest neighbors hopping interactions. For specific configurations, the system admits a flat band located between two dispersion bands, where three inequivalent Dirac valleys are identified. Furthermore, quasi-particles are effectively described by a spin-1 Dirac-type equation. Under external homogeneous magnetic fields, the Landau levels are exactly determined as the third-order polynomial equation for the energy can be solved using Cardano’s formula. It is also shown that an external anti-symmetric field promotes the existence of current-carrying states, so-called snake states, confined at the interface where the external field changes its sign.
Utilising nanosecond sources in diffuse optical tomography
Authors: Mozumder Meghdoot , Leskinen Jarkko , Tarvainen Tanja
Published: November 2022

Diffuse optical tomography (DOT) use near-infrared light for imaging optical properties of biological tissues. Time-domain (TD) DOT systems use pulsed lasers and measure time-varying temporal point spread function (TPSF), carrying information from both superficial and deep layers of imaged target. In this work, feasibility of nanosecond scale light pulses as sources for TD-DOT is studied. Nanosecond sources enable using relatively robust measurement setups with standard analogue-to-digital converter waveform digitizers, such as digital oscilloscopes. However, this type of systems have some properties, such as variations in source pulses and limited temporal sampling, that could limit their usage. In this work, these different aspects and possible limitations were studied with simulations and experiments. Simulations showed that information carried by TD data of diffuse medium is on low frequencies. This enables usage of relatively slow response time measurement electronics, and image processing using Fourier-transformed TD data. Furthermore, the temporal sampling in measurements needs to be high enough to capture the TPSF, but this rate can be achieved with standard digital oscilloscopes. It was shown that, although variations in light pulses of nanosecond lasers are larger than those of picosecond sources, these variations do not affect significantly on image quality. Overall, the simulations demonstrated the capability of nanosecond sources to be utilised in TD-DOT in diffuse medium. In this work, a prototype TD-DOT experimental system utilising a high-energy nanosecond laser was constructed. The system is relatively robust consisting of a nanosecond Nd:YAG laser combined with optical parametric oscillator for light input and optical fibres for guiding the light, and avalanche photodetector and high-bandwidth oscilloscope for TPSF measurements. The system was used in both absolute and difference imaging of two phantoms. The experiments verified that both absorbing and scattering objects can be reconstructed with good accuracy with TD-DOT using a nanosecond laser.
A new approach to simultaneously reducing, nitrogen doping and noble metal coating of graphene oxide via active-screen plasma
Authors: Jing Zhiyuan , Guo Weiling , Yu Helong , Qi Shaojun , Tao Xiao , Qiao Yulin , Zhang Wei , Li Xiaoying , Dong Hanshan
Published: November 2022

Graphene is widely used for various applications, especially after nitrogen doping and incorporation with metal nanoparticles. Herein, a simultaneous approach to reducing, nitrogen doping and noble metals coating of graphene oxide (GO) is reported using an advanced active-screen plasma (ASP) technique. With a noble metal plate added as an extra lid of active screen cage, the corresponding noble metal, mainly or fully in pure metal state, depending on the noble metal type, as well as a minority of Fe and Cr, is deposited on GO with simultaneous reduction and nitrogen doping. The ASP treated GO exhibits varying levels of improvement in electrical property depending on the type of noble metal nanoparticles hybridized with. Specifically, ASP treated GO incorporated with Pt or Au revealed 2–4 orders of magnitude of improvement in electrical property.
Discrepancy and rectifiability of almost linearly repetitive Delone sets
Authors: Smilansky Yotam , Solomon Yaar
Published: November 2022

We extend a discrepancy bound of Lagarias and Pleasants for local weight distributions on linearly repetitive Delone sets and show that a similar bound holds also for the more general case of Delone sets without finite local complexity if linear repetitivity is replaced by ɛ-linear repetitivity. As a result we establish that Delone sets that are ɛ-linear repetitive for some sufficiently small ɛ are rectifiable, and that incommensurable multiscale substitution tilings are never almost linearly repetitive.
CT scanner-specific organ dose coefficients generated by Monte Carlo calculation for the ICRP adult male and female reference computational phantoms
Authors: Jansen Jan TM , Shrimpton Paul C , Edyvean Sue
Published: November 2022

Objective. Provide analyses of new organ dose coefficients (hereafter also referred to as normalized doses) for CT that have been developed to update the widely-utilized collection of data published 30 years ago in NRPB-SR250. Approach. In order to reflect changes in technology, and also ICRP recommendations concerning use of the computational phantoms adult male (AM) and adult female (AF), 102 series of new Monte Carlo simulations have been performed covering the range of operating conditions for 12 contemporary models of CT scanner from 4 manufacturers. Normalized doses (relative to free air on axis) have been determined for 39 organs, and for every 8 mm or 4.84 mm slab of AM and AF, respectively. Main results. Analyses of results confirm the significant influence (by up to a few tens of percent), on values of normalized organ (or contributions to effective dose (E
103,phan)), for whole body exposure arising from selection of tube voltage and beam shaping filter. Use of partial (when available) rather than a Full fan beam reduced both organ and effective dose by up to 7%. Normalized doses to AF were larger than corresponding figures for AM by up to 30% for organs and by 10% for E
103,phan. Additional simulations for whole body exposure have also demonstrated that: practical simplifications in the main modelling (point source, single slice thickness, neglect of patient couch and immobility of phantom arms) have sufficiently small (<5%) effect on E
103,phan; mis-centring of the phantom away from the axis of rotation by 5 mm (in any direction) leads to changes in normalized organ dose and E
103,phan by up to 20% and 6%, respectively; and angular tube current modulation can result in reductions by up to 35% and <15% in normalized organ dose and E
103,phan, respectively, for 100% cosine variation. Significance. These analyses help advance understanding of the influence of operational scanner settings on organ dose coefficients for contemporary CT, in support of improved patient protection. The results will allow the future development of a new dose estimation tool.
Effects of neoclassical tearing modes and toroidal field ripple on lost alpha power in the SPARC tokamak
Authors: Braun A E , Kramer G J , Tinguely R A , Scott S D , Sweeney R M
Published: November 2022

Using the SPIRAL Monte Carlo, full particle-orbit simulation code, we investigate the effects of neoclassical tearing modes (NTMs) and toroidal field (TF) ripple on alpha power losses during steady-state operation of the SPARC primary reference discharge. Model perturbations for TF ripple and the

m

/

n
=
2

/

1

and

3

/

2

NTMs with exaggerated widths selected based on an H-mode plasma approaching thermal quench are added to a simulated SPARC magnetic equilibrium through which marker particles are tracked. The 3/2 and 2/1 NTMs are located at

ρ

p
o
l

∼
0.76

and

ρ

p
o
l

∼
0.86

respectively, well positioned to increase alpha particle transport into and within an outer lossy region of the plasma beyond

ρ

p
o
l

∼
0.8

where over 95% of lost alpha particles are born. Total alpha power losses are shown to increase modestly from 1.73% lost at a minimum to 2.34% lost at a maximum, and alpha particle surface power densities form localized hotspots on the first-wall near the low-field side midplane due to NTMs and TF ripple. We establish a conservative upper limit for first-wall alpha surface power densities on a toroidally symmetric wall for typical, flattop operation and motivate the consideration of NTMs in the design of three dimensional limiter surfaces for SPARC.
Characterization of YBa2Cu3O7−δ
coplanar resonator for microwave kinetic inductance detectors
Authors: Roitman Ariel , Shaulov A , Yeshurun Y
Published: November 2022

We demonstrate an improved YBa2Cu3O7−δ
-based microwave kinetic inductance detector with a quality factor

Q
i

∼
2.5
×

10
4

and noise equivalent power,

∼

10

−
12

W

Hz

−
1

at 10 K. Zero field cooled (ZFC) and field cooled (FC) measurements of the magnetic field dependence of the resonance characteristics, show substantially different behavior, indicating that both the screening currents and vortices play a role. The ZFC measurements exhibit a sharp decrease of the resonance frequency,

f
r

, and

Q
i

at low fields, up to the full penetration field, revealing the dominant role of the screening currents. In contrast, the FC measurements exhibit a moderate decrease of

f
r

and

Q
i

with field, revealing the role of vortices and reflecting the field dependence of the penetration depth in a d-wave superconductor.
Tensor-network approaches to counting statistics for the current in a boundary-driven diffusive system
Authors: Gu Jiayin , Zhang Fan
Published: November 2022

We apply tensor networks to counting statistics for the stochastic particle transport in an out-of-equilibrium diffusive system. This system is composed of a one-dimensional channel in contact with two particle reservoirs at the ends. Two tensor-network algorithms, namely, density matrix renormalization group and time evolving block decimation, are respectively implemented. The cumulant generating function for the current is numerically calculated and then compared with the analytical solution. Excellent agreement is found, manifesting the validity of these approaches in such an application. Moreover, the fluctuation theorem for the current is shown to hold.
Can sub-GeV dark matter coherently scatter on the electrons in the atom?
Authors: Guo Ji-Heng , Sun Yu-Xuan , Wang Wenyu , Wu Ke-Yun
Published: November 2022

A novel detection of sub-GeV dark matter is proposed in the paper. The electron cloud is boosted by the dark matter and emits an electron when it is dragged back by the heavy nucleus, namely the coherent scattering of the electron cloud of the atom. The survey in the x-ray diffraction shows that the atomic form factors are much more complex than the naive consideration. The results of the relativistic Hartree–Fock (RHF) method give non-trivial shapes of the atoms. The detailed calculation of the recoil of the electron cloud, the kinetics, the fiducial cross section and the corresponding calculation of detection rate are given analytically. The numerical results show that the limits of the RHF form factors are much more stringent than the recoil of a single electron, almost 4 orders stronger, and also give tight limitations compared to the Migdal effect below about several hundred MeV. The physical picture and the corresponding results are promising and need further exploration.
A numerical method to calculate dwell time for electron in semiconductor nanostructure
Authors: Xie Shi-Shi , Lu Mao-Wang , Chen Sai-Yan , Qin Ying-Jie , Wen Li , Chen Jia-Li
Published: November 2022

To some extent, the operational quickness of semiconductor devices depends on the transmission time of an electron through semiconductor nanostructures. However, the calculation of transmission time is very difficult, thanks to both the contentious definition of the transmission time in quantum mechanics and the complicated effective potential functions experienced by electrons in semiconductor devices. Here, based on an improved transfer matrix method to numerically solve the Schrödinger equation and H G Winful’s relationship to calculate the dwell time, we develop a numerical approach to evaluate the transmission time of an electron in semiconductor devices. Compared to the exactly resolvable case of the rectangular potential barrier, the established numerical approach possesses high precision and small error, which may be employed to explore the dynamic response and operating speed of semiconductor devices. This proposed numerical method is successfully applied to the calculation of dwell time for an electron in double rectangular potential barriers and the dependence of transmission time on the number of potential barriers is revealed.
Quantum carpets: efficiently probing fractional revivals in position-dependent mass systems
Authors: Bibi Tooba , Javed Sunia , Iqbal Shahid
Published: November 2022

Position-dependent-mass systems are of great importance in many physical situations, such as the transport of charge carriers in semiconductors with non-uniform composition and in the theory of many-body interactions in condensed matter. Here we investigate, numerically and analytically, the phenomenon of fractional revivals in such systems, which is a generic characteristic manifested by the wave-packet evolution in bounded Hamiltonian systems. Identifying the fractional revivals using specific probes is an important task in the theory of quantum measurement and sensing. We numerically simulate the temporal evolution of probability density and information entropy density, which manifest self-similarly recurring interference patterns, namely, quantum carpets. Our numerical results show that the quantum carpets not only serve as an effective probe for recognizing the fractional revivals of various order but they efficiently describe the effect of spatially-varying mass on the structure of fractional revivals, which is manifested as a symmetry breaking in their designs.
Model considering panic emotion and personality traits for crowd evacuation
Authors: Sun Hua-Kai , Chen Chang-Kun
Published: November 2022

Panic is a common emotion when pedestrians are in danger during the actual evacuation, which can affect pedestrians a lot and may lead to fatalities as people are crushed or trampled. However, the systematic studies and quantitative analysis of evacuation panic, such as panic behaviors, panic evolution, and the stress responses of pedestrians with different personality traits to panic emotion are still rare. Here, combined with the theories of OCEAN (openness, conscientiousness, extroversion, agreeableness, neuroticism) model and SIS (susceptible, infected, susceptible) model, an extended cellular automata model is established by the floor field method in order to investigate the dynamics of panic emotion in the crowd and dynamics of pedestrians affected by emotion. In the model, pedestrians are divided into stable pedestrians and sensitive pedestrians according to their different personality traits in response to emotion, and their emotional state can be normal or panic. Besides, emotion contagion, emotion decay, and the influence of emotion on pedestrian movement decision-making are also considered. The simulation results show that evacuation efficiency will be reduced, for panic pedestrians may act maladaptive behaviors, thereby making the crowd more chaotic. The results further suggest that improving pedestrian psychological ability and raising the standard of management can effectively increase evacuation efficiency. And it is necessary to reduce the panic level of group as soon as possible at the beginning of evacuation. We hope this research could provide a new method to analyze crowd evacuation in panic situations.