bluuebunny/crossref_metadata_2025 huggingface dataset:
Global gyrokinetic study of shaping effects on electromagnetic modes at NSTX aspect ratio with ad hoc parallel magnetic perturbation effects
Authors: Sharma A. Y. , Cole M. D. J. , Görler T. , Chen Y. , Hatch D. R. , Guttenfelder W. , Hager R. , Sturdevant B. J. , Ku S. , Mishchenko A. , Chang C. S.
Published: November 2022

Plasma shaping may have a stronger effect on global turbulence in tight-aspect-ratio tokamaks than in conventional-aspect-ratio tokamaks due to the higher toroidicity and more acute poloidal asymmetry in the magnetic field. In addition, previous local gyrokinetic studies have shown that it is necessary to include parallel magnetic field perturbations in order to accurately compute growth rates of electromagnetic modes in tight-aspect-ratio tokamaks. In this work, the effects of elongation and triangularity on global, ion-scale, linear electromagnetic modes are studied at National Spherical Torus Experiment (NSTX) aspect ratio and high plasma β using the global gyrokinetic particle-in-cell code XGC. The effects of compressional magnetic perturbations are approximated via a well-known modification to the particle drifts that was developed for flux-tube simulations [Joiner et al., Phys. Plasmas 17, 072104 (2010)], without proof of its validity in a global simulation, with the gyrokinetic codes GENE and GEM being used for local verification and global cross-verification. Magnetic equilibria are re-constructed for each distinct plasma profile that is used. Coulomb collision effects are not considered. Within the limitations imposed by the present study, it is found that linear growth rates of electromagnetic modes (collisionless microtearing modes and kinetic ballooning modes) are significantly reduced in a high-elongation and high-triangularity NSTX-like geometry compared to a circular NSTX-like geometry. For example, growth rates of kinetic ballooning modes at high-β are reduced to the level of that of collisionless trapped electron modes.
Current-driven magnetization dynamics and its correlation with magnetization configurations in perpendicularly magnetized tunnel junctions
Authors: Zhou Kaiyuan , Chen Lina , Chi Kequn , Fu Qingwei , Tao Zui , Liang Like , Gao Zhenyu , Li Haotian , Meng Hao , Liu Bo , Zhou Tiejun , Liu R. H.
Published: November 2022

We study spin-transfer-torque-driven magnetization dynamics of a perpendicular magnetic tunnel junction nanopillar. Through the combined investigations on spin-torque ferromagnetic resonance and microwave spectroscopy, it is found that the free layer (FL) and the weak pinned reference layer (RL) exhibit distinct dynamic behaviors. First, frequency vs field dispersion for the FL and RL shows an opposite trend as the field varies. Second, the FL can support a single spin-wave (SW) mode for both parallel and antiparallel configurations, while the RL exhibits spin-wave excitation only for the antiparallel state. Those two SW modes coexist at the antiparallel state, and their oscillation frequency exhibits a crossover phenomenon with increasing the external magnetic field, which could be helpful in the mutual synchronization of auto-oscillations for SW-based neuromorphic computing.
Redshift of the optical gap in ferrite doped Gd2O3
Authors: Azeem M. , Khurshid H. , Ahmad M. , Ali S. S.
Published: November 2022

We report the measurement of the optical bandgap in ferrite doped Gd2O3. Doping of the nickel zinc ferrite (Ni0.5Zn0.5Fe2O4) nanoparticles to Gd2O3 powder was done through thermal decomposition of the mixture at 1000 °C. The average grain size of the thermally decomposed mixture was determined to be around 95 nm and contained phases of cubic Gd2O3, GdO, and orthorhombic prisms of GdFeO3. The imaginary part of the complex dielectric function was calculated from the absorbance measurements that showed an optical bandgap at 1.8 eV. The observed value of the fundamental energy gap is on average 4.0 eV smaller than suggested by early experiments. A model for the ferrite doped Gd2O3 was constructed to suggest that the Ni, Zn, and Fe atoms occupy Gd sites in the Gd2O3 lattice. A new band at Γ point is formed due to the hybridization of the atomic orbitals of dopant and Gd3+ that shifts the fundamental absorption edge to the red part of the photon energy spectrum. Despite having a high density of negatively charged carriers contributed by the dopant, the onset of the direct interband transitions is clearly resolved.
Non-equilibrium statistical properties, path-dependent information geometry, and entropy relations in edge-localized modes in fusion plasmas
Authors: Kim Eun-jin , Hollerbach Rainer
Published: November 2022

We investigate time-varying turbulence statistical properties of edge-localized modes (ELMs) in fusion plasmas. By utilizing a simplified stochastic model, we calculate a time-dependent probability density function and various entropy-related quantities such as entropy, entropy production, entropy flux, mutual information, and information flow and path-dependent information geometry. A thorough analysis is performed to elucidate the effects on ELM dynamics (evolution, suppression, mitigation, etc.) of different values of stochastic noise and different forms of a time-varying input power. Furthermore, the time-irreversibility and hysteresis are investigated through the employment of forward and back processes where a time-varying input power varies mirror-symmetrically in time. Among all the statistical quantities, the path-dependent information geometry is shown to be a robust diagnostic for quantifying hysteresis and self-regulation as well as for an early detection of subtle changes in ELM dynamics, for example, caused by a sudden change in the input power.
Social norms of fairness with reputation-based role assignment in the dictator game
Authors: Li Qing , Li Songtao , Zhang Yanling , Chen Xiaojie , Yang Shuo
Published: November 2022

A vast body of experiments share the view that social norms are major factors for the emergence of fairness in a population of individuals playing the dictator game (DG). Recently, to explore which social norms are conducive to sustaining cooperation has obtained considerable concern. However, thus, far few studies have investigated how social norms influence the evolution of fairness by means of indirect reciprocity. In this study, we propose an indirect reciprocal model of the DG and consider that an individual can be assigned as the dictator due to its good reputation. We investigate the “leading eight” norms and all second-order social norms by a two-timescale theoretical analysis. We show that when role assignment is based on reputation, four of the “leading eight” norms, including stern judging and simple standing, lead to a high level of fairness, which increases with the selection intensity. Our work also reveals that not only the correct treatment of making a fair split with good recipients but also distinguishing unjustified unfair split from justified unfair split matters in elevating the level of fairness.
Which bath Hamiltonians matter for thermal operations?
Authors: vom Ende Frederik
Published: November 2022

In this article, we explore the set of thermal operations from a mathematical and topological point of view. First, we introduce the concept of Hamiltonians with a resonant spectrum with respect to some reference Hamiltonian, followed by proving that when defining thermal operations, it suffices to only consider bath Hamiltonians, which satisfy this resonance property. Next, we investigate the continuity of the set of thermal operations in certain parameters, such as energies of the system and temperature of the bath. We will see that the set of thermal operations changes discontinuously with respect to the Hausdorff metric at any Hamiltonian, which has the so-called degenerate Bohr spectrum, regardless of the temperature. Finally, we find a semigroup representation of (enhanced) thermal operations in two dimensions by characterizing any such operation via three real parameters, thus allowing for a visualization of this set. Using this, in the qubit case, we show commutativity of (enhanced) thermal operations and convexity of thermal operations without the closure. The latter is done by specifying the elements of this set exactly.
Momentum and pseudomomentum in a shallow water equation
Authors: Hanna J. A.
Published: November 2022

A basic shallow water system with variable topography is analyzed from the point of view of a Lagrangian derivation of momentum, energy, and pseudomomentum balances. A two-dimensional action and associated momentum equation are derived. The latter is further manipulated to derive additional equations for energy and pseudomomentum. This revealed structure emphasizes broken symmetries in space and a reference configuration and preserved symmetry in time.
Barkas effect in strongly magnetized plasmas
Authors: Jose Louis , Bernstein David J. , Baalrud Scott D.
Published: November 2022

Strongly magnetized plasmas, which are characterized by the particle gyrofrequency exceeding the plasma frequency, exhibit novel transport properties. For example, recent work showed that the friction force on a test charge moving through a strongly magnetized plasma not only consists of the typical stopping power component but also includes components perpendicular to the test charge's velocity. However, these studies only considered test charges that have the same sign as the charge of the plasma particles. Here, we extend these calculations to the case of charges with opposite signs (such as an ion interacting with strongly magnetized electrons). This is done with both a novel generalized Boltzmann kinetic theory and molecular dynamics simulations. It is found that the friction force changes dramatically depending on the sign of the interacting charges. Likewise, the stopping power component for oppositely charged particles decreases in magnitude compared with like-charged particles, and the perpendicular components increase in magnitude. Moreover, the difference between the two cases increases as the gyrofrequency becomes larger compared with the plasma frequency. The electrical resistivity is calculated from the friction force, where it is found that strong magnetization in conjunction with oppositely charged interactions significantly decreases the parallel resistivity and increases the perpendicular resistivity.
Multi-stage voltage droop compensation based on resonant circuit for unipolar solid-state Marx Generators
Authors: Rao Junfeng , Huang Yibo , Wang Xiuzhi , Zhuang Longyu , Zhuang Jie , Ji Zhenyu
Published: November 2022

The low-voltage droop of high-voltage pulses is required to provide stable pulsed electric fields in many applications. Increasing the capacitance of energy storage capacitors increases both the size and the cost of the system. In this paper, four compensation stages based on the resonant circuit have been inserted into a 16-stage solid-state Marx generator to compensate for the voltage droop in different conditions. The nearly linear part of the sinusoidal voltage is precisely added to the load during discharging as compensation, and the rectangular pulsed voltage with little droop can be realized. Different numbers of compensation stages and different resonant inductances can compensate the droop to different levels, which means the compensation effect is also adjustable. Moreover, these compensation stages can operate as common stages in Marx generators as long as we open-circuit the resonant circuits. Since the capacitors in resonant compensation stages are also charged in parallel with capacitors in common stages, no auxiliary power supply is required. Simulating and experimental results show that the droop of a 9 kV pulse can be ideally compensated over a 500 Ω resistive load at various pulse widths. The pulse width should be shorter than the length of the nearly linear part of the sinusoidal voltage.
Binary salt structure classification with convolutional neural networks: Application to crystal nucleation and melting point calculations
Authors: Scheiber H. O. , Patey G. N.
Published: November 2022

Convolutional neural networks are constructed and validated for the crystal structure classification of simple binary salts such as the alkali halides. The inputs of the neural network classifiers are the local bond orientational order parameters of Steinhardt, Nelson, and Ronchetti [Phys. Rev. B 28, 784 (1983)], which are derived solely from the relative positions of atoms surrounding a central reference atom. This choice of input gives classifiers that are invariant to density, increasing their transferability. The neural networks are trained and validated on millions of data points generated from a large set of molecular dynamics (MD) simulations of model alkali halides in nine bulk phases (liquid, rock salt, wurtzite, CsCl, 5-5, sphalerite, NiAs, AntiNiAs, and β-BeO) across a range of temperatures. One-dimensional time convolution is employed to filter out short-lived structural fluctuations. The trained neural networks perform extremely well, with accuracy up to 99.99% on a balanced validation dataset constructed from millions of labeled bulk phase structures. A typical analysis using the neural networks, including neighbor list generation, order parameter calculation, and class inference, is computationally inexpensive compared to MD simulations. As a demonstration of their accuracy and utility, the neural network classifiers are employed to follow the nucleation and crystal growth of two model alkali halide systems, crystallizing into distinct structures from the melt. We further demonstrate the classifiers by implementing them in automated MD melting point calculations. Melting points for model alkali halides using the most commonly employed rigid-ion interaction potentials are reported and discussed.
Electrically tuning near-field heat flux using metal–oxide–semiconductor structure considering gradient dielectric function distribution
Authors: Xu Deyu , Zhao Junming , Liu Linhua
Published: November 2022

We build a model to determine the dependency of near-field heat flux on bias voltage using the metal–oxide–semiconductor structures considering gradient distribution of dielectric function. Quantitative dependency of near-field heat flux exchanged by two biased metal–oxide–semiconductor structures on bias voltage is established. The distribution of carrier density and the resultant dielectric function in the semiconductor layer caused by the bias are determined. The corresponding near-field heat flux is calculated using an effective multilayer model. Significant tuning performance is demonstrated, which is due to the increase or decrease in high-frequency surface polariton states induced by the injection or extraction of major carriers. This work deepens the understanding of electrical control of near-field heat transfer with metal–oxide–semiconductor structures, promising for nanoscale thermal management devices and thermal circuits.
Parametric amplification of electromagnetic waves produced by a flux-flow-oscillator made of YBa2Cu3O7−δ Josephson junction arrays
Authors: Chesca Boris , John Daniel , Gaifullin Marat
Published: November 2022

We observe parametric amplification of electromagnetic (EM) waves produced by a flux-flow oscillator made of YBa2Cu3O7−δ Josephson junctions arrays coupled to the resonant modes of a millimeter wave Fabry–Pérot resonator at a pump frequency fP = 45 GHz. For temperatures in the range (30–45) K, the frequency fS of the EM signal to be amplified could be tuned continuously in the range (1–25) GHz by an applied B-field induced flux Φ with a one-flux-quantum Φ0 periodicity. Consequently, we measured a significant parametric gain that is almost frequency independent, with a maximum of (8–10.4) dB reached at 40 K. For temperatures in the range (14–30) K, the magnetic field tunability of fS is gradually suppressed to a minimum of (1–5) GHz range where a parametric gain between 5 and 6 dB was measured. With an appropriate adjustment of design/fabrication parameters, our results suggest that the development of tunable MW generators/detectors as well as parametric amplifiers made of high transition temperature superconductors and operating in a wide range of temperatures (10 mK–77 K) is a reasonable and appealing possibility.
Injection of low-energy SiCH5+ ion-beam to Si substrate during chemical vapor deposition process using methylsilane
Authors: Yoshimura Satoru , Sugimoto Satoshi , Takeuchi Takae , Murai Kensuke , Kiuchi Masato
Published: November 2022

Silicon carbide (SiC) films produced on Si substrates by the thermal chemical vapor deposition (CVD) method using methylsilane (MS) were compared with those made by the mass-selected ion-beam deposition (MSIBD) method using MS-derived 100 eV SiCH5+ ions. We also investigated the effect of SiCH5+ ion injections during the CVD process. When the substrate was 550 °C, no distinct peaks were found in the Fourier transform infrared (FTIR) spectroscopy spectra of the samples obtained by both CVD and MSIBD. By contrast, an obvious FTIR peak due to the presence of SiC was observed when SiCH5+ ions were injected to a substrate in conjunction with MS. In the case of 650 °C, we found that the film thickness was significantly increased when additional SiCH5+ ions were injected during the CVD process using MS. These results suggest that the interaction between MS and SiCH5+ has some effects on the SiC film formation at the substrate temperatures 550 and 650 °C. When the substrate temperature was set at 750 °C, the effect of the SiCH5+ ion injection on the SiC film formation was negligibly small compared to that of CVD.
Integrable delay-difference and delay-differential analogs of the KdV, Boussinesq, and KP equations
Authors: Nakata Kenta
Published: November 2022

Delay-difference and delay-differential analogs of the KdV and Boussinesq (BSQ) equations are presented. Each of them has the N-soliton solution and reduces to an already known soliton equation as the delay parameter approaches 0. In addition, a delay-differential analog of the KP equation is proposed. We discuss its N-soliton solution and the limit as the delay parameter approaches 0. Finally, the relationship between the delay-differential analogs of the KdV, BSQ, and KP equations is clarified. Namely, reductions of the delay KP equation yield the delay KdV and delay BSQ equations.
How to train your solver: Verification of boundary conditions for smoothed particle hydrodynamics
Authors: Negi Pawan , Ramachandran Prabhu
Published: November 2022

The weakly compressible smoothed particle hydrodynamics (WCSPH) method has been employed to simulate various physical phenomena involving fluids and solids. Various methods have been proposed to implement the solid wall as well as inlet and outlet boundary conditions. However, error estimation and the formal rates of convergence for these methods have not been carefully discussed or examined. In this paper, we use the method of manufactured solutions to verify the convergence properties of a variety of commonly employed solid, inlet, and outlet boundary implementations. In order to perform this study, we propose various manufactured solutions for different domains. On the basis of the convergence offered by these methods, we systematically propose a convergent WCSPH scheme along with suitable methods for implementing the boundary conditions. We also demonstrate the accuracy of the proposed scheme by using it to solve the flow past a circular cylinder. Along with other recent developments in the use of adaptive resolution, this paves the way for accurate and efficient simulation of incompressible or weakly compressible fluid flows using the SPH method.
Amplitude reflections and interaction solutions of linear and nonlinear acoustic waves with hard and soft boundaries
Authors: Ishaq Muhammad , Chen Zhi-Min
Published: November 2022

In this study, the propagation of a fundamental plane mode in a bifurcated waveguide structure with soft–hard boundaries is analyzed by using the Helmholtz equation. The explicit solution is given to this bifurcated spaced waveguide problem by means of matching the potential across the boundary of continuity. Amplitudes of the reflected field in all those regions have been evaluated, and the energy balance has been derived. We have observed the reflection of the acoustic wave against the wavenumber and shown its variation with the duct width. Convergence of the problem has been shown graphically. In our analysis, we notice that the reflected amplitude decreases as the duct spacing increases; as a result, the acoustic energy will increase as the duct spacing increases. It is expected that our analysis could be helpful to give better understanding of wave reflection in an exhaust duct system. We then reduce the linear acoustic wave equation to the Kadomtsev–Petviashvili (KP) equation. Multiple-periodic wave interaction solutions of the KP nonlinear wave equation are investigated, and the energy transfer mechanism between the primary and higher harmonics is explained, which, to the best of our knowledge, is overlooked.
Preface to special topic: The High Repetition Rate Frontier in High-Energy-Density Physics
Authors: Heuer P. V. , Feister S. , Schaeffer D. B. , Rinderknecht H. G.
Published: November 2022

High-repetition-rate (HRR) experiments can collect large datasets with high temporal, spatial, and/or parametric resolution or large numbers of repeat measurements for statistics. HRR experiments also enable new experimental designs, including active feedback control loops and novel diagnostics, that can improve the reproducibility as well as the quantity of measurements. Together, these attributes make HRR experiments ideal for performing high-quality repeatable science. Until recently, these techniques have not been applied to high-energy-density–physics (HEDP) experiments, which are typically restricted to repetition rates of a few per day. However, recent advancements in lasers, pulsed-power drivers, target fabrication, and diagnostics are starting to change this fact, opening an exciting new frontier of HRR HEDP experiments. A mini-conference on this subject at the 2021 meeting of the American Physical Society Division of Plasma Physics brought together members of this growing community. The “High Repetition Rate Frontier in High-Energy-Density Physics” special topic in Physics of Plasmas highlights current progress in this exciting area.
Diversity and population structure of indigenous chicken in Congo, using MHC-linked microsatellite LEI0258
Authors: Bigabwa Bigman Aganze , Nyanjom Steven Ger , Kyallo Martina , Juma John , Entfellner Jean-Baka Domelevo , Pelle Roger
Published: November 2022

Context Chickens are the most important livestock in the Democratic Republic of Congo in particular and in Africa in general; they are kept for their meat and eggs for nutrition and economic status. The availability of chicken diversity information is very important in selection of breeds and in conservation of genetic resources. Aims This study aimed to determine allelic variability, genetic diversity, and genetic relationships of the indigenous chicken populations from the South Kivu region to support breeding programs and genetic resource conservations. Methods The LEI0258 microsatellite marker within the major histocompatibility complex gene region was used for genotyping. The LEI0258 locus amplicon sequences of 163 indigenous chickens were analysed. Key results The number of R13 and R12 repeats varied from 1 to 21 and from 3 to 21 respectively, whereas several combinations of indels and single-nucleotide polymorphisms were observed in the microsatellite flanking regions. In total, 45 different LEI0258 alleles ranging from 193 to 473 bp were determined, including 14 private alleles (Np). Expected heterozygosity (He) varied from 0.864 (Mwenga) to 0.938 (Bukavu), with a mean of 0.911, and observed heterozygosity (Ho) ranged from 0.417 (Uvira) to 0.667 (Mwenga), with a mean of 0.519. The analysis of molecular variance (AMOVA) showed higher genetic variation within individuals (56%) than among individuals (43%) and among chicken populations (1%). Clustering into three admixed gene pools (K = 3) showed the relationships among the chicken populations. Conclusion The present study showed the existence of high genetic diversity in chicken populations from South Kivu. Implications This study provides information useful for better conservation and breeding strategies of indigenous chicken populations in South Kivu.
High pressure frozen oocytes have improved ultrastructure but reduced cleavage rates compared to conventionally fixed or vitrified oocytes
Authors: Reader K. L. , Pilbrow B. G. , Zellhuber-McMillan S. , Mitchell A. J. , Juengel J. L. , Morbeck D.
Published: November 2022

Context Live birth rates are lower for cryopreserved oocytes than for fresh IVF cycles, indicating a need for improved methodologies. Aims The aim of this study was to determine if high pressure freezing (HPF) could improve both ultrastructural preservation and cryopreserved oocyte quality when compared to conventional fixation and vitrification methods. Methods Sheep oocytes and embryos were prepared by HPF or vitrification, with or without cryoprotectants. Frozen oocytes were prepared for transmission electron microscopy or warmed, in vitro fertilised and the recovery and cleavage rates recorded. Key results Blastocyst rates were similar between fresh, HPF and vitrified embryos. HPF oocytes had improved ultrastructure compared to conventional fixation or vitrification, but had poorer survival and cleavage rates compared to vitrified oocytes. Freeze-substitution of cryopreserved oocytes and transmission electron microscopy demonstrated disruption of the oocyte ultrastructure in the presence of cryoprotectants. Conclusions Superior preservation of ultrastructure was observed in HPF oocytes compared to vitrification or conventional fixation methods. In the presence of CP, both embryos and oocytes could survive HPF and warming but oocytes had reduced development. Implications The HPF method has potential to be developed and lead to improved oocyte and embryo cryopreservation and outcomes for assisted reproduction.
Reproductive biology of the rainbow mudsnake (Enhydris enhydris) in West Java, Indonesia
Authors: Zakky Quraisy , Hamidy Amir , Priambada Slamet , Herlambang Alamsyah Elang Nusa , Arida Evy , Riyanto Awal , Mumpuni  , Shine Richard , Natusch Daniel J. D.
Published: November 2022

Context Unsustainable harvesting can threaten wildlife populations and jeopardise the livelihoods of people relying on wildlife resources. Although millions of rainbow mudsnakes (Enhydris enhydris) are harvested from wetland agroecosystems in tropical Asia each year, few detailed studies have been conducted on the biology of this species. Aims We aimed to address this knowledge gap by examining the reproductive biology and resilience to harvesting of E. enhydris, collecting from agricultural landscapes in West Java, Indonesia. Methods We measured and examined 1731 specimens that had been collected and killed for skins and meat near the city of Cirebon in West Java. Key results Most snakes that we examined were adults (94% of females, 88% of males), with females outnumbering males overall (69% female). Sex ratios varied seasonally and among processing facilities. Females attained larger body sizes than males, were more heavy-bodied, and had shorter tails relative to snout–vent length. Reproductive traits varied among months, with two peaks in the incidence of gravid snakes occurring in March and September. Litter sizes averaged 11.2 (range 2–31) and increased with maternal body size. About half of the adult females were reproductive (vitellogenic or gravid) at the time of collection. This proportion increased with maternal body size, such that 60–70% of large females were reproductive at the time of collection, suggesting that some females may produce two litters per year. Conclusions Rainbow mudsnakes remain exceptionally abundant in West Java, despite significant habitat modification and intensive harvesting. Implications The ability of this species to exploit anthropogenic subsidies in disturbed agricultural landscapes gives it access to plentiful food, and the resultant early maturation, frequent reproduction, and high fecundity enable it to withstand high levels of commercial offtake.
Bayesian phylogenetics illuminate shallower relationships among Trans-Himalayan languages in the Tibet-Arunachal area
Authors: Wu Mei-Shin , Bodt Timotheus A. , Tresoldi Tiago
Published: November 2022

Kho-Bwa, Hrusish, Mishmic, Tani, and Tshangla are language clusters that have been recurrently proposed as subgroups of the Trans-Himalayan (also known as Tibeto-Burman and Sino-Tibetan) language family. Nonetheless, their internal classification, as well as the relation with each other and with other linguistic groups in the family, is hitherto unresolved. We use lexical data on these groups and dated phylogenies to investigate such internal classifications. We base our examination on previous research into the language family in the Tibet-Arunachal area, and follow a computer-assisted approach of language comparison to perform Bayesian phylolinguistic analysis. As earlier phylogenetic studies on this family included little data related to this geographic area, we took a subset of the best available dataset and extended it with vocabularies for the Kho-Bwa and Hrusish clusters, also including one Mishmic, two Tani, two Tshangla, and five East Bodish languages to cover the major languages and linguistic subgroups neighboring these clusters. Our results shed light on the internal and external classification of the Kho-Bwa, Hrusish and Bodish languages, and allow us to share valuable experience on the extent to which similar approaches can be applied to the phylogenetic analysis of the Trans-Himalayan language family.
Preinitial denasalisation and palatal fortition in Khroskyabs and the Gyalrongic word for ‘man’
Authors: Lai Yunfan
Published: November 2022

There are four distinct forms conveying the meaning of ‘human, person, man’ across Gyalrongic languages. The default type (Japhugtɯ-rme),the rounded type (Khroskyabsvɟú), the Stau type (Geshizavdzi)and the uvular type (Geletuotaˈʁap). Except for the default type, which has cognates in many other Sino-Tibetan languages, the origins of the other types are to date obscure and understudied. This paper first studies the phenomena of preinitial denasalisation and palatal fortition in the history of Khroskyabs, and then puts forward etymological solutions to the rounded and Stau types based on these sound changes. Both types are historical compounds with the first element related to the default type. The second element of the rounded type is cognate with Tangutlụʶ¹‘man’, and the second element of the Stau type is cognate with Proto-Loloish *tsaŋ¹‘man’ (Bradley 1979).
Accusative alignment in the Old Tibetan switch reference system
Authors: Hill Nathan W.
Published: November 2022

The use ofནས་-nasto mark cross-clausal co-reference in Version I of the Old TibetanRāmāyaṇareveals accusative alignment in Tibetan syntax, which in turn vindicates the notion of ‘subject’ applied to Tibetan.
If you want to cross singularity, wrap it!
Authors: Nakayama Yu
Published: November 2022

In two-dimensional string theory, a probe D0-brane does not see the black hole singularity due to a cancellation between its metric coupling and the dilaton coupling. A similar mechanism may work in the Schwarzschild black hole in large D dimensions by considering a suitable wrapped membrane. From the asymptotic observer, the wrapped membrane looks disappearing into nothing while the continuation of the time-like trajectory beyond the singularity suggests that it would reappear as an instantaneous space-like string stretching from the singularity. A null trajectory can be extended to a null trajectory beyond the singularity. Not only the effective particle but an effective string from the wrapped membrane can exhibit the same feature.
Gauge invariants of linearized gravity with a general background metric
Authors: Garg Deepen , Dodin I Y
Published: November 2022

In linearized gravity with distributed matter, the background metric has no generic symmetries, and decomposition of the metric perturbation into global normal modes is generally impractical. This complicates the identification of the gauge-invariant part of the perturbation, which is a concern, for example, in the theory of dispersive gravitational waves (GWs) whose energy–momentum must be gauge-invariant. Here, we propose how to identify the gauge-invariant part of the metric perturbation and the six independent gauge invariants per se for an arbitrary background metric. For the Minkowski background, the operator that projects the metric perturbation on the invariant subspace is proportional to the well-known dispersion operator of linear GWs in vacuum. For a general background, this operator is expressed in terms of the Green’s operator of the vacuum wave equation. If the background is smooth, it can be found asymptotically using the inverse scale of the background metric as a small parameter.
ORKA: Object reconstruction using a K-approximation graph
Authors: Bossmann Florian , Ma Jianwei
Published: November 2022

Data processing has to deal with many practical difficulties. Data is often corrupted by artifacts or noise and acquiring data can be expensive and difficult. Thus, the given data is often incomplete and inaccurate. To overcome these problems, it is often assumed that the data is sparse or low-dimensional in some domain. When multiple measurements are taken, this sparsity often appears in a structured manner. We propose a new model that assumes the data only contains a few relevant objects, i.e. it is sparse in some object domain. We model an object as a structure that can only change slightly in form and continuously in position over different measurements. This can be modelled by a matrix with highly correlated columns and a column shift operator that we introduce in this work. We present an efficient algorithm to solve the object reconstruction problem based on a K-approximation graph. We prove optimal approximation bounds and perform a numerical evaluation of the method. Examples from applications including Geophysics, video processing, and others will be given.
Hierarchical domain structures associated with oxygen octahedra tilting patterns in lead-free (Bi1/2Na1/2)TiO3
Authors: Hu Dongli , Fan Zhongming , Sawyer William , Henderson Mitchell , Luo Duan , Liu Xiaoming , Gu Hui , Tan Xiaoli , Wen Jianguo
Published: November 2022

Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi1/2Na1/2)TiO3 ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the ‘orientation-domain’ is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the ‘meso-chemical-domain’ occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO3 perovskite structure, and the ‘nano-cluster-region’ runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi1/2Na1/2)TiO3 is also discussed.
Modeling families of particle distributions with conditional GAN for Monte Carlo SPECT simulations
Authors: Saporta Albert , Etxebeste Ane , Kaprelian Théo , Létang Jean Michel , Sarrut David
Published: November 2022

Objective. We propose a method to model families of distributions of particles exiting a phantom with a conditional generative adversarial network (condGAN) during Monte Carlo simulation of single photon emission computed tomography imaging devices. Approach. The proposed condGAN is trained on a low statistics dataset containing the energy, the time, the position and the direction of exiting particles. In addition, it also contains a vector of conditions composed of four dimensions: the initial energy and the position of emitted particles within the phantom (a total of 12 dimensions). The information related to the gammas absorbed within the phantom is also added in the dataset. At the end of the training process, one component of the condGAN, the generator (G), is obtained. Main results. Particles with specific energies and positions of emission within the phantom can then be generated with G to replace the tracking of particle within the phantom, allowing reduced computation time compared to conventional Monte Carlo simulation. Significance. The condGAN generator is trained only once for a given phantom but can generate particles from various activity source distributions.
Redshifted 21-cm bispectrum: impact of the source models on the signal and the
IGM physics from the Cosmic Dawn
Authors: Kamran Mohd , Ghara Raghunath , Majumdar Suman , Mellema Garrelt , Bharadwaj Somnath , Pritchard Jonathan R. , Mondal Rajesh , Iliev Ilian T.
Published: November 2022

The emissions from the first luminous sources drive the fluctuations in the 21-cm signal
at Cosmic Dawn (CD) via two main astrophysical processes, namely Lyα coupling and X-ray
heating, yielding a highly non-Gaussian signal. The impact of these processes on the 21-cm signal
and its non-Gaussianity depends on the properties of these first sources of light. In this work,
we consider different CD scenarios by varying two major source parameters i.e. the minimum halo
mass M
h, min and X-ray photon production efficiency f
X using the 1D radiative transfer code grizzly. We study the impact of variation in these source parameters on the large scale (K
1 =
0.16 Mpc-1) 21-cm bispectrum for all possible unique triangles in the Fourier domain. Our detailed
and comparative analysis of the power spectrum and bispectrum shows that the shape, sign and
magnitude of the bispectrum jointly provide a better measure of the signal fluctuations and its
non-Gaussianity than the power spectrum alone. We also conclude that it is important to study the
sequence of sign changes along with the variations in the shape and magnitude of the bispectrum
throughout the CD history to arrive at a robust conclusion about the dominant processes in the
intergalactic medium at different cosmic times. We further observe that among all the possible
unique k-triangles, the large-scale non-Gaussianity of the signal is best probed by the small
k-triangles in the squeezed limit and by triangle shapes in its vicinity. This opens up the
possibility of constraining the source parameters during the CD using the 21-cm bispectrum.
Learning to school in dense configurations with multi-agent deep reinforcement learning
Authors: Zhu Yi , Pang Jian-Hua , Gao Tong , Tian Fang-Bao
Published: November 2022

Fish are observed to school in different configurations. However, how and why fish maintain a stable schooling formation still remains unclear. This work presents a numerical study of the dense schooling of two free swimmers by a hybrid method of the multi-agent deep reinforcement learning and the immersed boundary-lattice Boltzmann method. Active control policies are developed by synchronously training the leader to swim at a given speed and orientation and the follower to hold close proximity to the leader. After training, the swimmers could resist the strong hydrodynamic force to remain in stable formations and meantime swim in desired path, only by their tail-beat flapping. The tail movement of the swimmers in the stable formations are irregular and asymmetrical, indicating the swimmers are carefully adjusting their body-kinematics to balance the hydrodynamic force. In addition, a significant decrease in the mean amplitude and the cost of transport is found for the followers, indicating these swimmers could maintain the swimming speed with less efforts. The results also show that the side-by-side formation is hydrodynamically more stable but energetically less efficient than other configurations, while the full-body staggered formation is energetically more efficient as a whole.
Enzymatically crosslinked hydrogel based on tyramine modified gelatin and sialylated chitosan
Authors: Ding Peng , Wei Qianqian , Tian Ning , Ding Xiaoyue , Wang Ling , Wang Bin , Okoro Oseweuba Valentine , Shavandi Amin , Nie Lei
Published: November 2022

The enzymatically crosslinked hydrogel could replicate the cellular microenvironment for biomedical applications. In the present study, to improve the cytocompatibility of chitosan (CS), sialic acid (SA) was introduced to CS to synthesize sialylated CS (CS-SA), and the tyramine (TA) was grafted to gelatin (G) to obtain TA modified gelatin (G-TA). The successful synthesis of CS-SA and G-TA was confirmed using 1H NMR and UV–Vis absorption spectra. The interpenetrating polymer networks G-TA/CS-SA (GC) hydrogel was then fabricated via blending G-TA and CS-SA solutions and crosslinked using horseradish peroxidase. The storage modulus (G′) of the fabricated GC hydrogels with different ratios of G-TA/CS-SA greatly varied during the formation and strain of hydrogels. With the increase of CS-SA concentration from 0% to 2%, the storage modulus of GC hydrogels was also observed to decrease from 1500 Pa to 101 Pa; the water uptake capacity of GC hydrogels increased from 1000% to 4500%. Additionally, the cell counting kit-8 and fluorescent images demonstrated the excellent cytocompatibility of GC hydrogels after culturing with NIH 3T3 cells. The obtained results indicated that the fabricated GC hydrogels might have potential in biomedical fields, such as wound dressing.
Emerging metal doped carbon dots for promising theranostic applications
Authors: Liang Ke , Ge Jiechao , Wang Pengfei
Published: November 2022

As a bridge between organic fluorophores and inorganic quantum dots, carbon dots (CDs) have been recognized as emerging nanotheranostics for biomedical applications owing to their distinctive merits such as superior optical properties, flexible modification, adjustable functionalities, and remarkable photoactive therapeutic outcome, etc. Compared to metal free CDs, the introduction of metal ion in CDs endowed metal-doped CDs (MCDs) with tunable optical properties and new intrinsic properties, thereby illustrating its different capabilities from metal-free CDs for bioimaging and therapy. This review aims to summarize the recent progress of photonic MCDs as emerging nanoagent for theranostic application such as disease-related diagnostic (involving biosensing and bioimaging) and cancer therapy. The challenges and potential development of MCDs in nanotheranostic fields are also discussed.
German stakeholder perceptions of an EU carbon border adjustment mechanism
Authors: Kuehner Ann-Kathrin , Jakob Michael , Flachsland Christian
Published: November 2022

The European Commission has proposed a carbon border adjustment mechanism (CBAM) that would apply the carbon price prevailing in the EU emissions trading system to import-related emissions. We conducted a survey to study perceptions of an EU CBAM among German key stakeholders from industry, civil society, and research in July 2021. We find that substantial support for CBAM exists as well as the expectation that the mechanism will eventually be introduced. We identified divergent views on key design options among stakeholder groups. Stakeholders from industry generally favour the continuation of free allocation of emissions allowances, rebates for exporters from the EU, coverage of only scope 1 emissions, and use of revenues for domestic spending. Stakeholders from civil society prefer phasing out free allocation, coverage only of imports, an emissions scope including all indirect emissions, exempting low-income countries and countries that do implement non-price-based climate policies, and the use of revenues to finance green transformation in low-income countries. Respondents from research would generally rather see free allocation being phased out, emissions coverage of scope 1 and 2, exemptions for low-income countries and countries that do implement non-price-based policies with comparable effects in relevant sectors and a transfer of revenues to support clean technologies in low-income countries and green technologies in the EU. Our survey design allows us to identify three cross-stakeholder group clusters, one containing stakeholders who are comparably more hesitant towards CBAM, a second one with respondents most in favour of introducing CBAM, as well as a ‘middle ground’ cluster which contains views that are often in between the other two. We also compare the survey responses to the design of the Commission’s CBAM proposal to identify the most likely points of political disagreement.
D = 11 dS
5 backgrounds with enhanced supersymmetry
Authors: Farotti D , Gutowski J B
Published: November 2022

We classify all warped dS
5 backgrounds in D = 11 supergravity with enhanced supersymmetry. We show that backgrounds preserving N = 16 supersymmetries consist of either a stack of M5 branes with transverse space

R

5

, or a generalized M5-brane configuration with transverse space

R

×

N
4

, where N
4 is a hyper-Kähler manifold and the M5-brane harmonic function is determined by a hyper-Kähler potential on N
4. Moreover, we find that there are no backgrounds preserving exactly N = 24 supersymmetries. Backgrounds preserving N = 32 supersymmetries correspond to either

R

1
,
10

or

A
d

S
7

×

S
4

.
Alternative symplectic structures in second–class constrained systems
Authors: López-Osorio M A , Martínez-Pascual E , Martínez Pascual Edgar
Published: November 2022

The classical description of second-class constrained systems using alternative pairs, comprising a symplectic structure and a primary Hamiltonian other than the canonical ones, is investigated. It is exhibited that the dynamical equations do not fix a unique pair and instead there may exist infinitely many of them whose difference is not exhausted by canonical transformations. The consequences on the symplectic structure of the reduced phase space are addressed, namely the effect of different pairs on the construction of Dirac bracket is explored. Since constrained systems can also be studied via the Faddeev–Jackiw symplectic analysis, the implementation of alternative pairs on this formalism is considered as well. It is shown that Dirac’s algorithm outcomes are independent of the type of alternative pairs considered here irrespectively to whether there are also first-class constraints in the system. Finally, some comments on the implications of our results in the path integral quantisation scheme are pointed out.
Onset of universality in the dynamical mixing of a pure state
Authors: Carrera-Núñez M , Martínez-Argüello A M , Torres J M , Torres-Herrera E J
Published: November 2022

We study the time dynamics of random density matrices generated by evolving the same pure state using a Gaussian orthogonal ensemble (GOE) of Hamiltonians. We show that the spectral statistics of the resulting mixed state is well described by random matrix theory (RMT) and undergoes a crossover from the GOE to the Gaussian unitary ensemble (GUE) for short and large times respectively. Using a semi-analytical treatment relying on a power series of the density matrix as a function of time, we find that the crossover occurs in a characteristic time that scales as the inverse of the Hilbert space dimension. The RMT results are contrasted with a paradigmatic model of many-body localization in the chaotic regime, where the GUE statistics is reached at large times, while for short times the statistics strongly depends on the peculiarity of the considered subspace.