Radial Density Research Articles

Vapor-Liquid phase transition of associating fluids in a functionalized cylindrical pore: a Monte Carlo study

In this study, we investigate the phase behaviour of associating fluids with two interacting sites inside a functionalised cylindrical pore using Grand Canonical Monte Carlo simulations. The structural behaviour of the coexisting liquid and vapor phases is characterised by the radial density, orientation, and bond formation inside cylindrical pores of different radii. The critical properties of the phase diagrams of the confined fluids were investigated as functions of the associating strengths at different pore sizes. The impact of site strength on the phase diagram is characterised by the critical and structural properties of the coexisting phases inside the cylindrical pore. The organisation of the associating fluids near the pore surface strongly depends on the surface – site interaction with the interfacial fluid molecules that propagate to the bulk regime of the system. Thus, the surface site density is a crucial parameter for manipulating the properties of coexisting phases and critical properties of the phase diagram.

Systematic analysis of strange single heavy baryons and * *Supported by the National Natural Science Foundation of China (11675265, 12175068), the Continuous Basic Scientific Research Project (WDJC-2019-13), the Leading Innovation Project (LC 192209000701) and the Central Government Guidance Funds for Local Scientific and Technological Development of China (Guike ZY22096024)

Motivated by the experimental progress in the study of heavy baryons, we investigate the mass spectra of strange single heavy baryons in the λ-mode, using the relativistic quark model and the infinitesimally shifted Gaussian basis function method. We show that experimental results are well captured using the predicted masses. The root mean square radii and radial probability density distributions of the wave functions are analyzed in detail. Meanwhile, the mass spectra allow us to successfully construct the Regge trajectories in the plane. We also preliminarily assign quantum numbers to the recently observed baryons, including , , , , , , , , , , , and . Finally, the spectral structure of strange single heavy baryons is discussed. Accordingly, we predict several new baryons that may be observed in forthcoming experiments.

Research on Electromagnetic Vibration Characteristics of a Permanent Magnet Synchronous Motor Based on Multi-Physical Field Coupling

Background and Purpose: The stator vibration characteristics are comprehensively mastered by considering the influence of winding and the housing structure on the stator modes. This effect is neglected in the research field of electromagnetic vibration of permanent magnet synchronous motors (PMSMs). Methods: The radial air-gap flux density equations and PMSM’s electromagnetic force density are derived, and then the harmonic characteristics of electromagnetic force density are studied. An equivalent finite element model of the stator is proposed that investigates the impacts of the winding and stator housing rules on the stator modal frequency. Finally, the harmonic response and acoustic analyses of electromagnetic vibration are carried out based on multi-physics field coupling. Results: The equivalent radiated power distribution laws and acoustic field of motor electromagnetic vibration under transient operating conditions are obtained. The theoretical analysis results are consistent with the experimental results. Conclusion: The obtained results show that the spatial order of the radial electromagnetic force is not equal to the order of the radial mode of the motor stator. The reason for this is that structural resonance is induced when the frequency components of the spatial radial electromagnetic force are coupled with the intrinsic frequency of the stator.

Why cosmic voids matter: nonlinear structure & linear dynamics

We use the Magneticum suite of state-of-the-art hydrodynamical simulations to identify cosmic voids based on the watershed technique and investigate their most fundamental properties across different resolutions in mass and scale. This encompasses the distributions of void sizes, shapes, and content, as well as their radial density and velocity profiles traced by the distribution of cold dark matter particles and halos. We also study the impact of various tracer properties, such as their sparsity and mass, and the influence of void merging on these summary statistics. Our results reveal that all of the analyzed void properties are physically related to each other and describe universal characteristics that are largely independent of tracer type and resolution. Most notably, we find that the motion of tracers around void centers is perfectly consistent with linear dynamics, both for individual, as well as stacked voids. Despite the large range of scales accessible in our simulations, we are unable to identify the occurrence of nonlinear dynamics even inside voids of only a few Mpc in size. This suggests voids to be among the most pristine probes of cosmology down to scales that are commonly referred to as highly nonlinear in the field of large-scale structure.

Evaluation of optical coherence tomography angiography changes in nonarteritic anterior ischemic optic neuropathy

To study the long-term microvasculature changes at the macula and the optic disk in eyes with nonarteritic anterior ischemic optic neuropathy (NAION).Patients with acute NAION of less than 6 weeks duration were included. Optical coherence tomography angiography (OCTA) of the macula and the optic disk was performed at baseline, 3 and 6 months and compared with the controls.The mean age of 15 patients was 52.25 (±9.06) years. The whole image superficial peripapillary density (42.49 ± 5.28) was significantly low when compared to that of control eyes (46.36 ± 2.09); similarly, radial peripapillary capillary density (49.35 ± 5.64) was also significantly reduced when compared to controls (53.45 ± 1.96, P < 0.05). These parameters showed significant progressive decrease at 3 and 6 months (P < 0.05). At the macula, both superficial (41.83 ± 3.64) and deep macular vasculature densities (47.30 ± 2.04) were significantly reduced when compared to control eyes (52.15 ± 4.84 and 55.13 ± 1.81, respectively). The vascular density at the macula remained stable at 3- and 6-months period.The study shows that the microvasculature in case of NAION is significantly reduced both in peripapillary area and in macular area.

Study of plasma parameters in high enthalpy ICP-heated wind tunnel by using single Langmuir probe

In this paper, a single probe (SP) has been designed for study plasma parameters of High enthalpy ICP-heated wind tunnel. It is found that the electron temperature in the core region is about 2.4 eV and that in the edge region is about 3–4 eV. At the maximum power of the High Enthalpy ICP-heated wind tunnel, the electron density reach 4.34 × 1013 cm-3. Meanwhile, the radial electron density distribution of SP is numerically integrated to calculate the line integral density, which is compared with the line integral density measured by 890 GHz HCN laser interferometer. The results show that the probe diagnosis results have the same trend as the laser diagnosis results. The line integral electron density measured by SP is 0.8 times higher than that measured by the HCN interferometer.

Annealing of swift heavy ion tracks in amorphous silicon dioxide

The annealing kinetics of the high energy ion damage in amorphous silicon dioxide (a-SiO2) are still not well understood, despite the material's widespread application in material science, physics, geology, and biology. This study investigates how annealing temperature, duration, and ambient environment affect the recovery of irradiation damage produced along the trajectory of swift heavy ions in a-SiO2. The track-annealing kinetics and the changing ion track morphology were investigated using synchrotron-based small-angle X-ray scattering (SAXS) and etching methods. We found that track annealing proceeds quicker near the sample surface demonstrated by a changing track etch rate as a function of depth. Measurements of ion tracks using SAXS show only small changes in the radial density distribution profile of the ion tracks. Activation energy of the annealing process at different sample depths was determined and the effect of the capping layer during the annealing process was also studied. Combination of oxygen diffusion and stress relaxation may contribute to the observed behaviour of preferential and anisotropic healing of the ion track. The results add to the fundamental understanding of ion track damage recovery and may have direct implications for materials for radioactive waste storage and solid state nanopores.

Consistent wide-range equation of state of silicon by a unified first-principles method

Using a unified method of the extended first-principles molecular dynamics, we report a wide-range (density $\ensuremath{\rho}=2.329--18.632$ $\mathrm{g}/{\mathrm{cm}}^{3}$, temperature $T=1.00\ifmmode\times\else\texttimes\fi{}{10}^{4}--1.29\ifmmode\times\else\texttimes\fi{}{10}^{8}$ K) equation of state (EOS) and principal Hugoniot of silicon, which agree well with experimental results, and then evaluate the precision of the results of first-principles calculations and a universal database. Moreover, we investigate the effects of finite-temperature exchange-correlation functionals and emphasize their importance and necessity in the warm dense matter regime, although it vanishes in the nondegenerate and fully degenerate limits. Finally, we show the ionic radial distribution function and density of electronic states to study the evolution of warm dense Si towards the classic plasma limit along its principal Hugoniot. The established standard theoretical EOS table of Si provides a benchmark for the development of high-precision first-principles methods and may improve radiation-hydrodynamics simulations of inertial confinement fusion and deepen the understanding of high-energy-density physics.

Steeper Scattered Disks Buckle Faster

Disks of low-mass bodies scattered by giant planets to large semimajor axis and constant periapsis orbits are vulnerable to a buckling instability. This instability exponentially grows orbital inclinations, raises periapsis distances, and coherently tilts orbits resulting in clustering of arguments of periapsis. The dynamically hot system is then susceptible to the formation of a lopsided mode. Here we show that the timescale of the buckling instability decreases as the radial surface density of the population becomes more centrally dense, i.e., steeper scattered disks buckle faster. Accounting for differential apsidal precession driven by giant planets, we find that ∼10 M ⊕ is sufficient for a primordial scattered disk in the trans-Neptunian region to have been unstable if .

Galaxy clusters in the Vela Supercluster – I. Deep NIR catalogues

ABSTRACT We present six deep Near-InfraRed (JHKs) photometric catalogues of galaxies identified in six cluster candidates (VC02, VC04, VC05, VC08, VC10, and VC11) within the Vela Supercluster (VSCL) as part of our efforts to learn more about this large supercluster, which extends across the zone of avoidance (ℓ = 272.°5 ± 20°, b = ±10°, at cz ∼ 18 000 km s−1). The observations were conducted with the InfraRed Survey Facility (IRSF), a 1.4-m telescope situated at the South African Astronomical Observatory (SAAO) in Sutherland. The images in each cluster cover $\sim 80{{\ \rm per\ cent}}$ of their respective Abell radii. We identified a total number of 1715 galaxies distributed over the six cluster candidates, of which only $\sim 15{{\ \rm per\ cent}}$ were previously known. We study the structures and richnesses of the six clusters out to the cluster-centric completeness radius of rc &amp;lt; 1.5 Mpc and magnitude completeness limit of $K_s^o\lt 15{_{.}^{\rm m}}5$, using their iso-density contour maps and radial density profiles. The analysis shows VC04 to be the richest of the six. It is a massive cluster comparable to the Coma and Norma clusters, although its velocity dispersion, σv = 455 km s−1, seems rather low for a rich cluster. VC02 and VC05 are found to be relatively rich clusters while VC08 is rather poor. Also, VC05 has the highest central number density among the six. VC11 is an intermediate cluster that contains two major subclusters while VC10 has a filament-like structure and is likely not to be a cluster after all.

Evaluation of the retina with optical coherence tomography angiography (OCTA) in patients with coronavirus (COVID-19) infection

The goal of this study is to compare the optical coherence tomography angiography (OCTA) findings in Coronavirus (COVID-19) positive adult and pediatric patients with those of healthy volunteers with the same demographic characteristics. The right eye of 157adults infected with covid, 168healthy adult volunteers, 40children (6-18years of age) infected with covid, and 44 healthy children (6-18years of age) were included in this prospective study. All participants underwent ophthalmological examination and OCTA. The OCTA findings were evaluated. Deep nasal density (DND), deep inferior density (DID), and deep parafoveal density (DPD) were significantly lower in the pediatric covid-affected group (PCAG) than in the pediatric healthy control group (PHCG) (P=0.034, P=0.029, P=0.022 respectively). On the other hand, radial peripapillary capillary vessel density (RPCVD) intra-disc measurements were significantly higher in the PCAG compared to the PHCG (P=0.025). There was no significant difference between the OCTA measurements of the adult covid-affected group (ACAG) and the adult healthy control group (AHCG). In our study, significant differences were found in OCTA measurements between the covid group and the healthy control group in children. Retinal microvascular changes may occur in patients with covid infection, and these patients might be followed for long-term retinal changes.

Increased peripapillary capillaries in patients with acute leukemia by using optical coherence tomography angiography

PurposeTo evaluate the radial peripapillary capillary vessel density (RPC-VD) and thickness of the retinal nerve fiber layer (RNFL) in acute leukemia (AL) and the associations of these characteristics with blood laboratory parameters. METHODSA cross-sectional study was performed at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from February 2019 to April 2022. Sixty eyes of 30 patients diagnosed with AL and sixty eyes of 30 matched healthy controls were included. Optical coherence tomography angiography (OCTA) in the 4.5-mm Angio Disc scan mode and the Ganglion cell complex scan mode were performed for all participants. Correlation analyses were used to examine the associations of RPC-VD and RNFL with blood laboratory parameters. RESULTSPatients in the AL group had significantly increased RPC-VD in the whole-image (51.42±0.35 vs. 49.52±0.36) and peripapillary fields (53.90±0.43 vs. 51.17±0.50) compared with people in the control group (all P<0.001), while no difference was found for RPC-VD in the inside optic disk fields in the two groups. The RNFL in the AL group was significantly thicker than that in the control group (131.10±3.89 μm vs. 115.03±2.22 μm, P<0.05). Complete blood count (CBC) parameters, including red blood cells, hemoglobin and hematocrit, had a significant negative correlation with RPC-VD and RNFL (all P <0.05). CONCLUSIONAn increased RPC-VD and a thicker RNFL are evidence of fundus changes in patients with early-stage AL, and these metrics may be related to decreases in red blood cells, hemoglobin and hematocrit.

Design and analysis of in-wheel motor with sinusoidal permanent magnet shape for electrical vehicles

This paper deals with the design and analysis of a surface-mounted outer rotor in-wheel motor (IWM) with the aim of reducing cogging torque and torque ripple for electric vehicles. The proposed IWM is equipped with axial sinusoidal surface-mounted permanent magnets (PMs), with the purpose of producing sinusoidal air gap flux density distribution, thus to realize sinusoidal back electromotive force (EMF) and smooth electromagnetic torque. To highlight the advantage of the proposed IWM, the conventional IWM with tile-shaped PMs and the IWM with stepwise-shaped PMs are also studied for comparison. The finite element method in the commercial software package is utilized to analyze the performance of the three motors, including the radial flux density of air gap, back EMF, cogging torque, and electromagnetic torque. Through the quantitative comparison, it is found that the proposed IWM greatly reduces the cogging torque, highly improves the sinusoidality of back EMF, and nearly eliminates the torque ripple.

Advances, Challenges, and Future Perspectives of Microwave Reflectometry for Plasma Position and Shape Control on Future Nuclear Fusion Devices.

Providing energy from fusion and finding ways to scale up the fusion process to commercial proportions in an efficient, economical, and environmentally benign way is one of the grand challenges for engineering. Controlling the burning plasma in real-time is one of the critical issues that need to be addressed. Plasma Position Reflectometry (PPR) is expected to have an important role in next-generation fusion machines, such as DEMO, as a diagnostic to monitor the position and shape of the plasma continuously, complementing magnetic diagnostics. The reflectometry diagnostic uses radar science methods in the microwave and millimetre wave frequency ranges and is envisaged to measure the radial edge density profile at several poloidal angles providing data for the feedback control of the plasma position and shape. While significant steps have already been given to accomplish that goal, with proof of concept tested first in ASDEX-Upgrade and afterward in COMPASS, important, ground-breaking work is still ongoing. The Divertor Test Tokamak (DTT) facility presents itself as the appropriate future fusion device to implement, develop, and test a PPR system, thus contributing to building a knowledge database in plasma position reflectometry required for its application in DEMO. At DEMO, the PPR diagnostic's in-vessel antennas and waveguides, as well as the magnetic diagnostics, may be exposed to neutron irradiation fluences 5 to 50 times greater than those experienced by ITER. In the event of failure of either the magnetic or microwave diagnostics, the equilibrium control of the DEMO plasma may be jeopardized. It is, therefore, imperative to ensure that these systems are designed in such a way that they can be replaced if necessary. To perform reflectometry measurements at the 16 envisaged poloidal locations in DEMO, plasma-facing antennas and waveguides are needed to route the microwaves between the plasma through the DEMO upper ports (UPs) to the diagnostic hall. The main integration approach for this diagnostic is to incorporate these groups of antennas and waveguides into a diagnostics slim cassette (DSC), which is a dedicated complete poloidal segment specifically designed to be integrated with the water-cooled lithium lead (WCLL) breeding blanket system. This contribution presents the multiple engineering and physics challenges addressed while designing reflectometry diagnostics using radio science techniques. Namely, short-range dedicated radars for plasma position and shape control in future fusion experiments, the advances enabled by the designs for ITER and DEMO, and the future perspectives. One key development is in electronics, aiming at an advanced compact coherent fast frequency sweeping RF back-end [23-100 GHz in few μs] that is being developed at IPFN-IST using commercial Monolithic Microwave Integrated Circuits (MMIC). The compactness of this back-end design is crucial for the successful integration of many measurement channels in the reduced space available in future fusion machines. Prototype tests of these devices are foreseen to be performed in current nuclear fusion machines.

Radially graded metal foams arrangement in heat storage device of photothermal utilization systems

Metal foam was adopted for improving inherent low thermal conductivity of traditional thermal energy storage (TES), which conducted higher solar energy conversion efficiency. With consideration of more energy response and the mixing enhancement effect on heat conduction and natural convection, this work investigated a vertical TES tube in solar energy photothermal utilization systems, embedded in metallic foam with radial gradient porosity and pore density. Experiments and simulations have both been carried out. It is thoroughly examined how the liquid fraction, solid-liquid interface, temperature field, and velocity field evolve, and the properties of energy storage, such as heat transfer density and energy storage quantity, are further assessed. Results demonstrated that the melting duration was shortened by 11.2% for the positive radially graded porosity arrangement and prolonged by 16.8% for the negative, in comparison to the homogeneous structure. Meanwhile, influenced by the varied porosity, the temperature uniformity was enhanced by 4.9% for the positive and was deteriorated by 15.1% for the negative. In addition, positive and negative gradient pore density respectively increased the temperature uniformity of by 15.1% and 16.7%. Based above, metal foam tube with negative gradient porosity and pore density was suggested to build the more efficient photothermal solar energy conversion systems due to faster melting process and more homogeneous temperature uniformity.

Enlightening the dynamical evolution of Galactic open clusters: an approach usingGaiaDR3 and analytical descriptions

ABSTRACTMost stars in our Galaxy form in stellar aggregates, which can become long-lived structures called open clusters (OCs). Along their dynamical evolution, their gradual depletion leave some imprints on their structure. In this work, we employed astrometric, photometric, and spectroscopic data from the Gaia DR3 catalogue to uniformly characterize a sample of 60 OCs. Structural parameters (tidal, core, and half-light radii, respectively, rt, rc, and rh), age, mass (Mclu), distance, reddening, Jacobi radius (RJ), and half-light relaxation time (trh) are derived from radial density profiles and astrometrically decontaminated colour–magnitude diagrams. Ages and Galactocentric distances (RG) range from 7.2$\, \lesssim \,$log(t.yr$^{-1})\, \lesssim \,$9.8 and 6$\, \lesssim \, R_G$(kpc)$\, \lesssim \,$12. Analytical expressions derived from N-body simulations are also employed to estimate the OC initial mass (Mini) and mass loss due to dynamical effects. Both rc and the tidal filling ratio, rh/RJ, decrease with the dynamical age (= t/trh), indicating the shrinking of the OCs’ internal structure as consequence of internal dynamical relaxation. This dependence seems differentially affected by the external tidal field, since OCs at smaller RG tend to be dynamically older and have smaller Mclu/Mini ratios. For $R_G\lesssim 8\,$ kpc, the rh/RJ ratio presents a slight positive correlation with RG. Beyond this limit, there is a dichotomy in which more massive OCs are more compact and less subject to tidal stripping compared to those less massive and looser OCs at similar RG. Besides, the rt/RJ ratio also correlates positively with RG.

Stability of the state of two-electron atoms near to critical nuclear charge

Critical stability of the metastable bound state of two-electron atoms near the critical nuclear charge Z c (smaller than which the bound state ceases to exist) is investigated by employing the explicitly correlated Hylleraas-configuration interaction basis function. Our numerical calculation shows that, when the nuclear charge decreases to Z c , the ionization energy of the system approaches zero linearly and this behavior is fully consistent with the Hellmann–Feynman theorem. Radial and angular physical quantities as well as the inner and outer electron radial density distributions are calculated to reveal the classical geometric structure of the two-electron atom. The inner electron can be well modeled by a hydrogenic model in the 2 p state and its density distribution does not change much as the nuclear charge is changed. The outer electron, which is still localized in a finite region near the nucleus before the system transforms into a well-defined resonance, is shifted notably into a far-distance region. The critical stability of the system near the bound-continuum limit is therefore dominated by the outer electron.

Vascular changes in macula, optic disc, and choroid in Wilson's disease: A cross-sectional optical coherence tomography angiography study

PurposeTo evaluate the changes in the retinal and optic disc (OD) microcirculation in patients with Wilson's disease (WD) using optical coherence tomography angiography (OCTA). Materials and MethodsThis cross-sectional comparative study included 35 eyes of 35 WD patients (study group) and 36 eyes of 36 healthy participants (control group). The patients with WD were divided into subgroups based on the presence of Kayser-Fleischer rings. All the participants underwent a comprehensive ophthalmological examination, including OCTA. ResultsThe inferior perifoveal deep capillary plexus vessel density (DCP-VD), inferior radial peripapillary capillary vessel density (RPC-VD), and inferior peripapillary retinal nerve fiber layer (PPRNFL) thickness were significantly lower in the WD group than in the healthy participants (p=0.041, p=0.043, and p=0.045, respectively). In addition, in the subgroup analysis, the superior RPC-VD and inferior PPRNFL were significantly lower in the subgroup with Kayser-Fleischer rings (p=0.013 and p=0.041, respectively). ConclusionWe showed there to be changes in certain OCTA parameters in WD patients when compared with healthy controls. Thus, we hypothesized that OCTA could detect any retinal microvascular changes in WD patients without clinical evidence of retinal or OD involvement.

Effects of a radial variation of surface coefficients on plasma uniformity in capacitive RF discharges

With the increasing demands toward large area plasma etching and deposition, the radial uniformity of capacitively coupled plasmas (CCPs) becomes one of the key factors that determine process performance in industrial applications. However, there is a variety of parasitic effects, e.g. electromagnetic and electrostatic edge effects, that typically lead to the formation of nonuniform radial plasma density profiles at various discharge conditions with a density peak appearing either at the center or near the edges of the electrodes. Moreover, in commercial CCPs different surface materials are in contact with the plasma at various positions as parts of boundary surfaces such as focus rings, masks, showerhead electrodes, wall and/or target materials. Via complex material specific plasma-surface interactions, the presence of such different surface materials affects plasma uniformity in a way that is typically not understood and, thus, not controlled. In this work, aided by 2d3v graphics processing unit accelerated particle-in-cell/Monte Carlo collision simulations, we study the effects of radial variations of electrode materials on the plasma via their different ion and electron induced secondary electron emission as well as electron reflection coefficients on the discharge characteristics. Based on such fundamental understanding we tailor the radial variation of boundary surface materials to improve plasma uniformity in low pressure CCPs. Such investigations are performed at different neutral gas pressures, where both center and edge high radial plasma density profiles form in the presence of radially uniform surface coefficients that resemble the presence of a single electrode material. It is demonstrated that by radially varying the surface coefficients at the grounded electrode, the radial plasma density profile can be finely adjusted and the plasma uniformity above the wafer placed at the powered electrode can be improved in both cases.

Witnessing the fragmentation of a filament into prestellar cores in Orion B/NGC 2024

Context. Recent Herschel observations of nearby molecular clouds have shown that filamentary structures are ubiquitous and that most prestellar cores form in dense filaments. Probing the detailed density and velocity structure of molecular filaments is therefore crucial for improving our observational understanding of the star formation process. Aims. We aim to characterize both the density and the velocity field of a typical molecular filament in the process of fragmenting into cores. Methods. We mapped a portion of the NGC 2024 region in the Orion B molecular cloud with the Nobeyama 45m telescope, in the 12CO (J = 1–0), 13CO (J = 1–0), C18O (J = 1–0), and H13CO+ (J = 1–0) lines, and the southwestern part of NGC 2024, corresponding to the NGC 2024S filament, with the NOrthern Extended Millimeter Array (NOEMA) interferometer in H13CO+ (J = 1–0). Results. The maps of 13CO, C18O, and H13CO+ emission trace at least part of the filamentary structure seen in the 8″ resolution ArTéMiS+Herschel data. The median radial column density profile of the NGC 2024S filament as derived from ArTéMiS+Herschel dust emission data is well fitted by a Plummer profile with a half-power diameter DHPPlummer=0.081±0.014 pc, which is similar to the findings of previous studies of nearby molecular filaments with Herschel. On the other hand, the half-power diameters of NGC 2024S as measured from the Nobeyama 13CO and C18O data are broader than, and the half-power diameter derived from the H13CO+ data narrower than the filament diameter measured with Herschel. These results suggest that the 13CO and C18O data trace only the (low-density) outer part of the Herschel filament and the H13CO+ data only the (dense) inner part. We identify four cores in the portion of the Herschel map covered by NOEMA and find that each Herschel core corresponds to a single core detected in the combined NOEMA+45m H13CO+ data cube. The Nobeyama H13CO+ centroid velocity map reveals velocity gradients along both the major and the minor axis of the NGC 2024S filament, as well as velocity oscillations with a period λ ~0.2 pc along the major axis. Comparison between the centroid velocity and the column density distribution shows a tentative λ/4 phase shift in H13CO+ or C18O. This λ/4 shift is not simultaneously observed for all cores in any single tracer but is tentatively seen for each core in either H13CO+ or C18O. The difference between the H13CO+ and C18O velocity patterns may arise from differences in the range of densities probed by H13CO+ and C18O. We produced a toy model that takes into account the three velocity-field components: a transverse velocity gradient, a longitudinal velocity gradient, and a longitudinal oscillation mode caused by fragmentation. Examination of synthetic data shows that the longitudinal oscillation component produces an oscillation pattern in the velocity structure function of the model. Since the velocity structure function of the Nobeyama H13CO+ centroid velocity data does show an oscillation pattern, we suggest that our observations are partly tracing core-forming motions and the fragmentation of the NGC 2024S filament into cores. We also find that the mean core mass in NGC 2024S corresponds to the effective Bonnor-Ebert mass in the filament. This is consistent with a scenario in which higher-mass cores form in higher-line-mass filaments.