bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectrum‐sensing algorithm based on graph feature fusion
Authors: Wu Shanshan , Hu Guobing , Gu Bin
Published: December 2024

Graph‐based spectrum sensing in noisy environments has major implications for civilian and military signal processing applications. However, existing algorithms suffer from high computational complexity and performance deterioration at low signal‐to‐noise ratios (SNRs). Therefore, a spectrum‐sensing algorithm based on graph feature fusion using a quadratic form derived from self‐loop weights and the graph Laplacian matrix is proposed in this study. The sum of the first and second block maxima of the power spectrum of the observed signal is selected as the input to the graph converter. Self‐loop weights are combined with the Laplacian matrix to construct the graph quadratic form, which serves as the test statistic for decision‐making. By applying majorisation and the extreme value theory, it is demonstrated that the proposed algorithm outperforms existing methods. The simulation results confirm the robust spectrum‐sensing performance across various signal modulation types and pulse shapes. Thus, compared to existing algorithms, except block range‐ and energy‐detection‐based methods, the proposed algorithm demonstrates the best spectrum‐sensing performance under low SNRs and channel‐fading conditions, while achieving the lowest computational complexity. The proposed approach enables more efficient and accurate spectrum sensing, fostering advancements in communication technologies and defence applications.
Observation of discontinuities accompanied by interplanetary shock within the Martian magnetosheath
Authors: He Linxia , Guo Jianpeng
Published: December 2024

As fast forward interplanetary (IP) shocks travel outward in the IP medium, they might encounter planetary bow shocks (BSs) and then propagate into the magnetosheath. The interaction of an IP shock with a BS could create a new discontinuity, which has been predicted by theory and simulations, and commonly observed at Earth. Nevertheless, it is still uncertain whether such a phenomenon occurs at unmagnetized planets like Mars. Here, we present the first experimental observation of a discontinuity-like structure that follows a transmitted IP shock within the Martian magnetosheath. This event was recorded by the MAVEN spacecraft on March 3, 2015. The comparison of spacecraft measurements with theoretical studies indicates that the discontinuity-like structure is a compound structure in nature, composed of the slow expansion wave, contact discontinuity, and slow shock, launched by the interaction of a fast IP shock with the Martian BS. The results shed light on the similarities between magnetized and unmagnetized planets in response to the passage of IP shocks.
The nature of LOFAR rotation measures and new constraints on magnetic fields in cosmic filaments and on magnetogenesis scenarios
Authors: Carretti E. , Vazza F. , O’Sullivan S. P. , Vacca V. , Bonafede A. , Heald G. , Horellou C. , Mtchedlidze S. , Vernstrom T.
Published: December 2024

The measurement of magnetic fields in cosmic web filaments can be used to reveal the magnetogenesis of the Universe. In previous works, we produced the first estimates of the field strength and its redshift evolution using the Faraday rotation measure (RM) catalogue of extragalactic background sources at a low frequency obtained with LOFAR observations. For this work, we refined our analysis by selecting sources with a low Galactic RM, which reduces its residual contamination. We also conducted a comprehensive analysis of the different contributions to the extragalactic RMs along the line of sight, and confirm that they are dominated by the cosmic filaments’ component, with only 21 percent originating in galaxy clusters and the circumgalactic medium (CGM) of galaxies. We find a possible hint of a shock at the virial radius of massive galaxies. We also find that the fractional polarisation of background sources might be a valuable CGM tracer. The newly selected RMs have a steeper evolution with redshift than previously found. The field strength in filaments (Bf) and its evolution were estimated assuming Bf evolves as a power law Bf = Bf, 0 (1 + z)α. Our analysis finds an average strength at z = 0 of Bf, 0 = 11–15 nG, with an error of 4 nG, and a slope α = 2.3–2.6 ± 0.5, which is steeper than what we previously found. The comoving field has a slope of β = [0.3, 0.6]±0.5 that is consistent with being invariant with redshift. Primordial magnetogenesis scenarios are favoured by our data, together with a sub-dominant astrophysical-origin RM component increasing with redshift.
The twin blow-up method for Hamilton–Jacobi equations in higher dimension
Authors: Forcadel Nicolas , Imbert Cyril , Monneau Régis
Published: December 2024

In this paper, we show how to extend the twin blow-up method recently developped by the authors (Comptes Rendus. Math., 2024), in order to obtain a new comparison principle for an evolution coercive Hamilton–Jacobi equation posed in a domain of an Euclidian space of any dimension and supplemented with a boundary condition. The method allows dealing with the case where tangential variables and the variable corresponding to the normal gradient of the solution are strongly coupled at the boundary. We elaborate on a method introduced by Lions and Souganidis (Atti Accad. Naz. Lincei, 2017). Their argument relies on a single blow-up procedure after rescaling the semi-solutions to be compared while two simultaneous blow-ups are performed in this work, one for each variable of the classical doubling variable technique. A one-sided Lipschitz estimate satisfied by a combination of the two blow-up limits plays a key role.
Stellenwert körperlicher Aktivität und Messung körperlicher
Beweglichkeit bei Patienten mit axialer Spondyloarthritis
Authors: Kiefer David , Kiltz Uta , Sewerin Philipp , Baraliakos Xenofon
Published: December 2024

Die axiale Spondyloarthritis (axSpA) ist eine chronische rheumatische Erkrankung,
die auf Grund von entzündlichen Prozessen und strukturellen Veränderungen im
Achsenskelett zu erheblichen Einschränkungen der körperlichen Funktionsfähigkeit
und der Beweglichkeit der Betroffenen führen kann. Neben der medikamentösen
Therapie spielt regelmäßige körperliche Aktivität eine zentrale Rolle im
Management der axSpA. Verschiedene Messmethoden wie der BASFI oder der BASMI
werden eingesetzt, um die körperliche Funktionsfähigkeit und Beweglichkeit zu
evaluieren. Leistungstests und moderne Technologien wie Tracker oder
elektronische Messmethoden bieten neue Ansätze zur objektiven und präzisen
Erfassung von körperlicher Aktivität und Bewegungsausmaß. Dieser
Übersichtsartikel beleuchtet die Bedeutung körperlicher Aktivität, aktueller
Messmethoden und innovativer Ansätze für die Behandlung von Patienten mit
axSpA.
Therapeutic Challenges in the Management of Collecting Duct Carcinoma of the Kidney: A Case Report with Review of Literature
Authors: Edayattil Arathi , Vadakke Sanudev Sadanandan , Jabir Mohamed , NK Supriya , James Vivek Mathew , Ariyannur Prasanth S
Published: December 2024

Collecting duct carcinoma (CDC) of the kidney is a rare type of renal cell carcinoma. It is an aggressive tumor with a poor prognosis and limited treatment options. A 67-year-old man, during evaluation for hematuria, loss of appetite and weight loss, and flank pain, was found to have a left renal mass with lung and bone metastasis. He underwent a left radical nephrectomy, and histopathological examination confirmed CDC. He received palliative chemotherapy with carboplatin and gemcitabine. Computed tomography (CT) scan after three cycles showed partial response. Chemotherapy was stopped due to worsening renal function after five cycles. Immunohistochemical studies done for programmed cell death ligand 1(PDL1) SP263 and Her2 neu were negative. Next-generation sequencing for 75 therapeutically actionable gene panels showed loss of function mutation in the neurofibromatosis type 1 (NF1) gene. Missense mutations involving Platelet derived growth factor receptor alpha gene (PDGFRA), FAT atypical cadherin 1 (FAT1), and Androgen receptor (AR) genes were reported as variants of unknown significance. No clinically relevant alterations were detected in liquid biopsy. Consequently, he was started on sunitinib. After 2 months, he developed brain metastasis and was treated with whole brain radiation therapy. Systemic therapy was changed to single-agent Nab-paclitaxel. After three cycles, he developed a cutaneous metastasis in the forearm and chemotherapy was changed to single-agent doxorubicin. After three cycles of doxorubicin, he succumbed to the disease. He survived for 16 months after diagnosis. The first-line treatment for metastatic CDC is chemotherapy with gemcitabine and cisplatin. There is no established second-line treatment. In this era, next-generation sequencing for targetable genetic alterations can help us select the treatment for subsequent lines of therapy.
Relationship between food triggers and sensory hypersensitivity in patients with migraine
Authors: Vitali-Silva Aline , Bello Valéria Aparecida , Poli-Frederico Regina Célia , Oliveira Carlos Eduardo Coral de , Reiche Edna Maria Vissoci , Bossa Beatriz Bagatim , Rezende Debora Villas Boas , Khouri Bárbara Ferreira , Silva-Néto Raimundo Pereira
Published: December 2024

Background The recognition of food as the trigger of attacks occurs in approximately 25% of individuals with migraine. However, differentiating migraine food triggers and prodrome symptoms is still a challenge.

Objective To understand the association of clinical characteristics of migraine with food triggers and to identify predictors of food triggers.

Methods Patients with migraine diagnosed according to the criteria of the third edition of the International Classification of Headache Disorders (ICHD-3) were evaluated for the presence or absence of food triggers.

Results In total, 502 patients with migraine were investigated, and they were divided into two groups: those with food triggers (58.4%) and those without food triggers (41.6%). The main food triggers were alcohol (44%), chocolate (42%), cheese (27.7%), excess carbohydrates (27.7%), coffee (21.8%), cold cuts (16%), and citrus fruits (11.9%). Aura and excessive use of analgesics were more frequent among patients with food triggers (p = 0.022). Photophobia and osmophobia were associated with the presence of a food trigger (p < 0.001). There was a greater impact of migraine in the presence of food triggers (p = 0.002). Through binary logistic regression, we identified clinical predictors of food triggers, such as photophobia and osmophobia.

Conclusion The presence of a food trigger was significantly associated with photophobia and osmophobia. Osmophobia might be another mechanism by which patients perceive foods as triggers for their migraine attacks.
Cyberflashing Lacan
Authors: Ramsey Sarah M. , Hook Derek W.
Published: December 2024

We explore cyberflashing through the lens of Lacanian psychoanalysis, including such notions as anxiety, the gaze, Law, castration and disavowal. Many instances of cyberflashing qualify as a perverse act, an act which is driven by anxiety, and which involves inducing anxiety or jouissance (libidinal enjoyment) in another. Our account helps explain the repetitive nature of such acts in the face of negative reactions and despite their frequent failure to achieve what might be seen to be their more immediate aim (that of arousing the recipient of the message and encouraging them to have sex with the sender).
Modulation of laser-driven proton beams in underdense plasma
Authors: Cheng H. , Li Y. Z. , Yan Y. , Fang Y. L. , Xia Y. D. , Li C. T. , Huang M. F. , Yan Y. T. , Lin C. , Yan X. Q.
Published: December 2024

Particle-in-cell simulations have been carried out to investigate the behavior of pulsed proton beams accelerated by laser within underdense plasma. The results reveal that wakefields generated by the proton beam effectively focus the proton beam, improving the beams' spatial distribution and energy spread. Additionally, electron rotations, inspired by an external longitudinal magnetic field, form a transverse focusing field near the proton beam, by which the proton beam can be focused more effectively. This implies the possibility of utilizing plasma as a viable medium for transport and focusing laser-accelerated broadband-energy proton beams, offering solutions to preserve and improve the proton beam properties, which is crucial for a variety of applications of laser-accelerated proton beams.
R3c to P4bm phase transition assisted small to large polaron crossover in sodium bismuth titanate-based ferroelectrics
Authors: Samantaray Koyal Suman , Sasmal Dilip , P. Maneesha , Sen Somaditya
Published: December 2024

Sodium bismuth titanate (NBT) reveals a rhombohedral (R3c) phase at room temperature. Ferroelectricity reduces with the advent of a tetragonal (P4bm) phase at the depolarization temperature, Td ∼ 456 K. AC conductivity (σac) studies exposed a small-to-large polaron transition at Td. Barrier energy (WH) was ∼1.60 eV at T < Td for the small polarons in the R3c phase, which drastically reduced to ∼0.043 eV with the advent of the P4bm phase for the large polarons for T > Td. This is associated with the sharp rise in conductivity for T > Td. Ab initio calculations consider the electronic distortion due to oxygen vacancies, which creates trap states in the band structure. The energy gap (ΔE) between the trap states and the conduction band was ∼1.4 eV (R3c) and ∼0.2 eV (P4bm). These values are comparable to the experimental WH. The P4bm phase is more distorted than the R3c phase from charge density and structural distortion calculations. This indicates the formation of large polarons in the P4bm phase, compared to that of small polarons in R3c. The formation energy of the polaron (Epolaron) was calculated from the structural distortion and electron localization energies. The P4bm phase shows lower Epolaron (−0.26 eV) than R3c (−0.36 eV), indicating higher conductivity for the P4bm phase. NBT was chemically modified by adding BCZT to validate the small to large polaronic crossover at Td. This is discussed in light of σac measurements. WH decreased with BCZT incorporation, thereby increasing the conductivity. This is a consequence of the increased lattice distortion due to BCZT incorporation.
Spurious radiated power signal following massive material injections in JET and the effect of neutral gas pressure on resistive bolometers
Authors: Schoonheere N. , Reux C. , Meister H. , Beyer P. , Carvalho P. , Coffey I. , Lawson K. , Puglia P. , Sheikh U. ,   JET Contributors,   the EUROfusion Tokamak Exploitation Team
Published: December 2024

Massive material injections in the JET tokamak have been observed to substantially affect resistive bolometer measurements, resulting in a spurious radiated power signal proportional to the quantity injected and reaching up to 8 MW. These bolometers are calibrated and designed to operate in near vacuum but certain scenarios requiring large gas injections can push the neutral pressure past nominal values. This study demonstrates that the bolometry measurement can be affected at neutral pressures above 0.1 Pa following injections with standard gas valves, shattered pellet injections, and particularly massive gas injections. The power measurement of resistive bolometers is based on the temperature difference between a measurement sensor exposed to radiation and a shielded reference sensor. We employ a thermal conductivity model to demonstrate that the conduction through the gas and the distinct geometries between the sensors can affect their cooling efficiency. This additional cooling pathway, coupled with the Joule heating from the applied voltage causes the equilibrium temperatures of the sensors to diverge. Being the very basis of the measure, this temperature difference induces a signal that is erroneously interpreted as radiated power. Experiments show large discrepancies in the response to neutral pressure among bolometer channels, attributed to variations in channel physical parameters. Nonetheless, the modeled total radiated power reproduces the experimental measurements within an order of magnitude, affirming the sensitivity of resistive bolometers to neutral pressure and gas species.
Effect of physical vapor deposition on contacts to 2D MoS2
Authors: Saifur Rahman M. , Agyapong Ama D. , Mohney Suzanne E.
Published: December 2024

Two-dimensional (2D) molybdenum disulfide (MoS2) holds immense promise for next-generation electronic applications. However, the role of contact deposition at the metal/semiconductor interface remains a critical factor influencing device performance. This study investigates the impact of different metal deposition techniques, specifically electron-beam evaporation and sputtering, for depositing Cu, Pd, Bi, Sn, Pt, and In. Utilizing Raman spectroscopy with backside illumination, we observe changes at the buried metal/1L MoS2 interface after metal deposition. Sputter deposition causes more damage to monolayer MoS2 than electron-beam evaporation, as indicated by partial or complete disappearance of first-order E′(Γ)α and A′1(Γ)α Raman modes post-deposition. We correlated the degree of damage from sputtered atoms to the cohesive energies of the sputtered material. Through fabrication and testing of field-effect transistors, we demonstrate that electron-beam evaporated Sn/Au contacts exhibit superior performance including reduced contact resistance (~12×), enhanced mobility (~4.3×), and lower subthreshold slope (~0.6×) compared to their sputtered counterparts. Our findings underscore the importance of contact fabrication methods for optimizing the performance of 2D MoS2 devices and the value of Raman spectroscopy with backside illumination for gaining insight into contact performance.
Blue sky catastrophe in the phenomenological model of neuron–astrocyte interaction
Authors: Barabash Nikita V. , Levanova Tatiana A. , Smirnov Lev A.
Published: December 2024

We study a bifurcation scenario that corresponds to the transition from bursting activity to spiking in a phenomenological model of neuron–astrocyte interaction in neuronal populations. In order to do this, we numerically obtain one-dimensional Poincaré return map and highlight its bifurcation structure using an analytically constructed piecewise smooth model map. This map reveals the existence of a cascade of period-adding bifurcations, leading to a bursting–spiking transition via blue sky catastrophe.
Oxidation induced amorphicity and subsequent delayed crystallization in binary transition metal alloy NbMo
Authors: Homsma M. D. , van den Beld W. T. E. , van de Kruijs R. W. E. , Ackermann M. D.
Published: December 2024

Multi-Principle Element Alloys (MPEAs) are a new material that shows high promise for new applications but lacks a fundamental understanding of where its change compared to mono-metals comes from. Studying simplified cases via binary alloys allows us to demonstrate such changes in relative isolation compared to the complicated high entropy alloy case. Through temperature-ramped in-air annealing, thin (100nm) NbMo films are shown to form quasi-amorphous oxide, as is also observed by TEM (Transmission Electron Microscopy). Our observations suggest that the act of mixing in oxygen causes the alloy to change phases, which can be reasoned by considering oxygen as a hypothetical third metallic particle whose inclusion breaks the Hume-Rothery rules. Consequently, the alloy, including oxygen, is unable to form a single solution, which is observed with the phase turning amorphous rather than mixed crystalline. As such, this work makes a first step in trying to find fundamental characteristics that allow us to predict thin film MPEA behavior in order to show how alloys behave in oxidizing and reducing environments.
Influence of the interfacial topological effect on the behavior of transport current in MgB2 material in the Meissner state and mixed state
Authors: Gajda Daniel , Babij Michał , Zaleski Andrzej , Rindfleisch Matt
Published: December 2024

Our research showed that a physical phenomenon appears in MgB2 wires, which has not been reported in previous studies. We have found that the flow of transport current in the current penetration depth of normal metal areas leads to the creation of voltage in magnetic fields from 0 to Bc1. Scanning electron microscope (SEM) images showed that normal areas can be formed at the junction between the superconducting material and the diffusion barrier. SEM photos indicate that this surface is very non-homogeneous and porous. This new physical phenomenon, that is, the voltage created by these normal areas at the current penetration depth is called, in this paper, the interfacial topological effect. Further measurements showed that above Bc1, the voltage disappears and becomes unmeasurable for magnetic fields above 120 mT. This is due to the appearance of a mixed state and current flow at a deeper depth of the superconducting material. From the interfacial topological effect, transport current flows on the outside surface of the superconducting MgB2 wires not only in magnetic fields from 0 to Bc1 but also in the mixed state and disappears in magnetic fields above 120 mT. This indicates that it is related to the superconducting state. The measurements performed by using a physical property measurement system (PPMS) for the low current (100 mA) indicate that the interfacial topological effect is on the boundary of two superconducting materials: the Nb diffusion barrier and the MgB2 material. In addition, the PPMS measurement results point out that the magnetic field eliminates the interfacial topological effect. Further results indicate that the appearance of voltage (the interfacial topological effect) in a MgB2 coil does not mean that the coil is not superconducting and cannot conduct the transport current without loss. Our results indicate that test procedures for MgB2 coils should assume exceeding the magnetic field of 120 mT because in this field, the voltage can disappear to zero and the transport current flows without loss. This is a very important factor for the future production of superconducting coils made of MgB2 wires with the Nb barrier on an industrial scale.
Be2B monolayer as a well-balanced performance anode for lithium-ion batteries with ultrahigh theoretical capacity and low diffusion barrier
Authors: Lu Zheng , Liu Chun-Sheng , Ye Xiao-Juan
Published: December 2024

Lithium-ion batteries (LIBs) are the most crucial part of energy storage systems. The lower molar weight of anodes can achieve a higher theoretical capacity. We explore the performance of a Be2B monolayer as an anode for LIBs. By first-principles calculations, we reveal that the Be2B monolayer shows excellent tensile strength, which suggests that it can deal with the volume expansion during the adsorption process. Furthermore, the Be2B monolayer can stably adsorb Li atoms with an adsorption energy of −0.98 eV. Moreover, the Be2B monolayer exhibits a low diffusion barrier (0.066 eV), an ultra-high theoretical capacity (3717 mA h g−1), and a moderate open circuit voltage (0.59 V). We also confirm the wettability of the Be2B monolayer in common electrolytes and investigate the adsorption and diffusion properties of Li on Be2B/graphene heterostructure. The introduction of graphene enhances the migration behavior of Li, suggesting the fast charging/discharging capability. Based on the above-mentioned properties, we propose that the Be2B monolayer can act as a high-performance anode material.
The decomposition pathways of C4F7N/CO2/O2 mixtures in the PTFE vapors
Authors: Liu Sijie , Li Xiaolong , Geng Zhenxin , Lin Ying
Published: December 2024

The C4F7N/CO2/O2 mixtures have better arc-extinguishing performance compared to the C4F7N/CO2 mixtures, and they have a broader application prospect as a substitute for SF6 in high-voltage circuit breakers and gas insulated substation pipelines. Under high-temperature conditions, the polytetrafluoroethylene (PTFE) vapor produced by insulating materials can affect the decomposition path of the C4F7N/CO2/O2 mixed gas, thereby impacting the arc-extinguishing performance of the mixed gas. This paper conducts quantum chemical calculations based on density functional theory to study the decomposition mechanism of the C4F7N/CO2/O2 mixed gas under the influence of PTFE vapor. This study optimizes the structure of reactants and intermediates and evaluates the energy of molecules using the Gaussian-4 theoretical method. By analyzing the potential energy of the decomposition paths that the C4F7N/CO2/O2 mixed gas may undergo under PTFE vapor, the final decomposition path of the mixed gas under PTFE vapor is obtained. This research can provide a reference for the development of environmentally friendly gases in the study of high-voltage circuit breakers.
Contact force measurement of the compliant gripper based on a force sensing model
Authors: Du Yunsong , Zhang Pengwei , Li Tiemin
Published: December 2024

It is challenging for most existing grippers to accurately measure their contact force when grasping unstructured objects. To address this issue, a novel force sensing model is established. A compliant gripper derived by the topology optimization method is introduced, and its actual deformation is measured without contacting by OpenCV. Meanwhile, the hyperelastic constitutive model of flexible materials is further studied by the uniaxial compression test to improve the accuracy of its theoretical deformation. Subsequently, the force sensing model is established based on linear finite element theory and the deep neural network (DNN) algorithm. The nonlinear errors of actual deformation (input layer) and theoretical deformation (output layer) are compensated by the DNN algorithm. This compensated deformation is then input into the linear force sensing model to determine the contact force. Finally, experimental results show that the gripper has a high force sensing accuracy (average error less than 3%) in the middle part. While the force sensing accuracy at the end of the compliant gripper has declined, the contact force measurement of the model in the middle of the new compliant gripper has been effectively verified.
A fluorescence approach for assessing the composition of evaporating droplets
Authors: Stiti M. , Wang M. , Chaynes H. , Isaiev M. , Castanet G.
Published: December 2024

Accurate measurement of chemical composition is vital for understanding heat and mass transfer mechanisms in two-phase flows like sprays. This Letter presents an optical method based on laser-induced fluorescence and fluorescence lifetime measurement. While solvatochromism—shifts in the emission and absorption spectra based on solvent type that alter fluorescence intensity—is well-documented for many fluorescent dyes, fluorescence lifetime offers distinct advantages for two-phase flow applications. Unlike intensity-based methods, lifetime measurements exhibit greater resilience to light attenuation and scattering at liquid/gas interfaces and allow for more flexible detection band selection. The technique leverages the fluorescence lifetime of eosin Y, which is sensitive to solvent polarity while remaining unaffected by temperature—a crucial feature for systems with fluctuating temperature and composition. We validate this method using acoustically levitated droplets, showing that eosin Y's fluorescence lifetime can reliably distinguish components in binary mixtures like ethanol/water and isopropanol/water. The high volatility of ethanol and isopropanol causes significant cooling during droplet vaporization, leading to water condensation from the surrounding air. This approach enables detailed analysis of complex evaporation and condensation dynamics.
A new generalized formulation of dielectric tensor for multi-species plasma with anisotropic drift product-bi-kappa distribution
Authors: Bai Wei , Wu Chenchen , Pu Yanxu , He Yaqiang , Chen Hao , Yu Pengcheng , Zhang Xiaohui , Liu Yu
Published: December 2024

It is well established that space plasmas often contain particle components with high-energy tails that approximately follow a power-law distribution in velocity space. Such superthermal distributions, particularly those with an excess of fast particles, are more accurately described by generalized Kappa (Lorentzian) distributions rather than Maxwellian distributions. We propose the product-bi-kappa (PBK) distribution as an alternative to the kappa-Maxwellian (KM) and bi-Maxwellian (BM) distributions, leading to a new linear transformation form of the dielectric tensor for multi-component plasmas. This method utilizes the rational form and multi-pole expansion of the plasma dispersion function to convert the dielectric tensor of multi-component PBK plasmas into a linear eigenvalue system in conjunction with Maxwell's equations. Our approach transforms the traditional numerical iteration process for solving the finite roots of the dielectric tensor from initial values into an eigenvalue problem within a new, complete linear system, thus enabling the simultaneous determination of all principal eigenvalues. Constructing the eigenvalue system for multi-component plasmas is crucial for developing new, comprehensive oblique propagation solvers for multi-species anisotropic drift plasmas, including PBK, KM, and BM plasmas. The detailed construction of the linear eigenvalue system is extensively discussed in this work.
Uncovering the lung cancer mechanisms through the chromosome structural ensemble characteristics and nucleation seeds
Authors: Chu Wen-Ting , Wang Jin
Published: December 2024

Lung cancer is one of the most common cancers in humans. However, there is still a need to understand the underlying mechanisms of a normal cell developing into a cancer cell. Here, we develop the chromosome dynamic structural model and quantify the important characteristics of the chromosome structural ensemble of the normal lung cell and the lung cancer A549 cell. Our results demonstrate the essential relationship among the chromosome ensemble, the epigenetic marks, and the gene expressions, which suggests the linkage between chromosome structure and function. The analysis reveals that the lung cancer cell may have a higher level of relative ensemble fluctuation (micro CFI) and a higher degree of phase separation between the two compartments than the normal lung cell. In addition, the significant conformational “switching off” events (from compartment A to B) are more than the significant conformational “switching on” events during the lung cancerization. We identify “nucleation seeds” or hot spots in chromosomes, which initiate the transitions and determine the mechanisms. The hot spots and interaction network results reveal that the lung cancerization process (from normal lung to A549) and the reversion process have different mechanisms. These investigations have revealed the cell fate determination mechanism of the lung cancer process, which will be helpful for the further prevention and control of cancers.
A versatile setup for hydrogen isotope permeation studies
Authors: Sand P. , Manhard A. , von Toussaint U.
Published: December 2024

The Testbed for Analysis of Permeation of Atoms in Samples (TAPAS) is an experimental setup for ion-driven permeation studies with a focus on investigating wall materials for nuclear fusion devices. A monoenergetic, mass-filtered high-intensity keV ion beam is focused and directed onto the permeation sample by electrostatic ion optics and decelerated to the desired ion energy by a dedicated set of apertures close to the sample. We were able to obtain ion energies as low as 170 eV/D with a D3+ ion beam with an ion flux density of the order of 1020 D/m2s on a beam-wetted area of ∼33 mm2. These conditions avoid sputtering of W targets by the ion beam and are representative of the particle flux and energy spectrum impinging on the first wall of a prospective nuclear fusion power reactor. Permeation samples can be heated up to 1000 K in an ultra-high vacuum. The design of the deceleration system, together with a high pumping speed in the loading chamber, ensures a low pressure of recycling hydrogen isotope molecules in front of the sample. In addition to ion-driven permeation, TAPAS provides a limited capability for gas-driven permeation at low pressures up to nearly 1 mbar. Permeating hydrogen isotopes are detected with a quadrupole mass spectrometer in the downstream ultra-high vacuum chamber. After a detailed description of the setup and calibration procedures for implanted particle flux, mass spectrometer, and neutral gas pressure, benchmark experiments on recrystallized, 50 μm thick tungsten foils are shown, demonstrating that diffusion-limited boundary conditions for permeation were reached.
Spatial resolution of a velocity-selected ion imaging microscope for surface reaction kinetics mapping
Authors: Smoll Eric J. , Patterson Brian D. , Chandler David W. , Kliewer Christopher J.
Published: December 2024

Experimental validation of complex microkinetic models derived from quantum chemistry is crucial for the advancement of bottom-up approaches to heterogeneous catalysis. State-of-the-art velocity-resolved kinetics experiments have made tremendous progress in this arena but integrate reactivity over centimeter-scale single-crystal catalytic surfaces even when complex spatial phenomena may perturb the kinetic results. We report a new design, optimization, and analysis of an ion imaging microscope that can collect spatially resolved kinetic data from a catalytic surface. In its simplest configuration, gaseous reaction products are ionized by a laser line or sheet above a catalytic surface. The resulting ions are extracted and strongly lensed to an intermediate velocity-mapped plane where a pinhole of radius r only transmits ions produced from reaction products with desorption velocities within a narrow solid angle centered on the surface normal. Transmitted ions re-expand through an electrostatic zoom lens to form a spatial image of the initial reaction product distribution with reduced blur from desorption velocity components parallel to the surface. The ion hits that define the magnified and deblurred spatial image can be used to determine spatiotemporal flux and speed-distributions of gas leaving the catalyst surface. Electrostatic trajectory simulations are performed and verify that transmission is ∝r2/TSurface. However, calculated global point spread functions acting on the magnified image have a width that is ∝r and largely independent of TSurface. Thus, velocity-filtered ion imaging microscopy can deliver a consistent resolution as the TSurface is varied, which is a great advantage because many catalytic reactions require elevated temperatures.
Coherence mode and Floquet analysis on flow past a rectangular cylinder with small angle of attack
Authors: Qiao Lingyu , Zhao Ying , Zhou Lei , Ai Yifeng , Zhu Qingchi , Zhang Hongfu
Published: December 2024

This paper focuses on a typical bluff body, a rectangular cylinder with an aspect ratio of 5, and quantitatively analyzes the fluid force coefficients and Strouhal number (St) under different angles of attack (α) and Reynolds numbers (Re) through numerical simulations. The higher-order dynamic mode decomposition method is used for coherence mode analysis, and Floquet instability analysis is used to identify the 3D transitional angle of attack (α3D) at different Re as well as the Floquet modes at various α. The results show that increasing the angle of attack significantly raises the mean drag coefficient (C¯D) and fluctuating lift coefficient (C′L), while the St number gradually decreases. This leads to the emergence of vortices and complex flow structures of different scales and frequencies at the rear edge of the rectangular cylinder and its lower cavity region, accompanied by increased downstream turbulence intensity. Furthermore, the 3D transitional angle of attack (α3D) decreases with increasing Re. Two types of Floquet modes are identified within the range of Re and α, namely, Mode A and Quasi-Periodic Mode QP. This study provides important insights and theoretical support for a deeper understanding of flow evolution problems.
Structural changes in honeycomb layers of Mn3NiTa2O9 under pressures up to 14 GPa using in situ synchrotron x-ray diffraction
Authors: Singh H. , Seehra M. S. , Irshad K. A. , Joseph B. , Prellier W. , Thota S.
Published: December 2024

Changes in the structural parameters of trigonal honeycomb layers of Mn3NiTa2O9 are reported under pressures up to 14 GPa by in situ synchrotron x-ray diffraction employing a diamond anvil cell with a 4:1 methanol–ethanol mixture as the pressure transmitting medium (PTM). The lattice parameters a, c, the ratio c/a, and the volume V of the unit cell all decrease almost linearly with an increase in pressure P up to a critical pressure PC = 9.2 GPa. The fit of the V vs P data for P < PC to the expression for the equation of state yields the bulk modulus = 144.5 GPa for the trigonal Mn3NiTa2O9. For P > PC, the widths of the Bragg lines increase, and their intensities decrease rapidly. By employing the Williamson–Hall analysis of the linewidths, the observed changes above P > PC can be interpreted as due to rapidly increasing strain together with a decrease in the effective micro-crystallite size D. However, at this critical pressure, the hydrostatic conditions change due to the solidification of the PTM. The observed significant effects on the broadening of the Bragg lines and their rapid intensity reduction, together with an increasing trend seen in the lattice parameter, may be due to interstitial defects produced by shear stress (as a result of non-hydrostaticity) present for P > PC with the parameter D reflecting mean defect-free distance.
Prediction of coal structures and its gas-bearing properties based on geophysical logging parameters: A case study in Anze block, China
Authors: Zhang Kun , Li Ming , Meng Zhaoping
Published: December 2024

Coal structures are widely regarded as a critical influencing factor for the dynamic behaviors of CH4 migration in coalbed methane (CBM) reservoir. In this paper, geophysical logging data were analyzed to explore the logging response characteristics of coal structures, and their application on identification of coal structures by using the machine learning methods. Meanwhile, the correlations between coal structures and gas-bearing properties were revealed. The results show that with the increase in coal deformation intensities, acoustic transit time, caliper logging, compensated neutron, and natural gamma values positively increase and that for density logging and lateral resistivity show a negative correlation. The multi-logging parameter identification models of coal structures were constructed by using random forest algorithm, radial basis function neural network, and long short-term memory neural network, with their accuracy reaching to 96.67%, 93.33%, and 91.67%, respectively. Based on the identification results of RFA model, the highest distribution percentages of cataclastic coal are 50.2%, which is controlled by tectonic activities and buried depth. The origins of gases are mainly thermogenic gases whose average value of δ13C(CH4) is −37.51‰. The gas content in granulated coal is smaller than 12 cm3/g, but it is higher than 15 cm3/g in cataclastic coal, resulting the higher gas saturation of cataclastic coal. The average extension length of artificial fractures in cataclastic coals is nearly two times as long as in granulated coals. It is suggested that cataclastic coal zone is the favorable area for CBM development.
Research on the flow field and trajectory characteristics of high-speed projectile entry water in waves
Authors: Guo Zeqing , Liu Rushi , Sun Shuai , Zhang Huanhao
Published: December 2024

The high velocity of supercavitating projectiles in a wave environment alters the flow characteristics and water entry stability, which significantly impacts the development and application of supercavitating weapons. This paper, investigates the effects of waves on the oblique water entry of high-speed supercavitating projectiles using computational fluid dynamics, with Stokes' second-order wave theory as the foundation for wave simulations. The numerical simulation method is validated through high-speed water entry experiments. The analysis explores the impact of wave inclination on cavity formation and the forces acting on the projectile. The results reveal that variations in wave inclination change the actual water-entry angles, affecting the cavitation structure near the free surface, modifying the impact intensity on the tail fins during water contact, and ultimately influencing the hydrodynamic forces acting on the projectile. When the actual water-entry angles are similar, the forces on the projectile during entry remain consistent under different conditions, with the trajectory being determined by the entry angle. Additionally, a reduction in the actual water-entry angle improves the projectile's entry stability but increases the amplitude and frequency of tail slap, ultimately affecting the stability of the projectile's trajectory after water entry.
Evolution of cooperation with early social influence for explaining collective action
Authors: He Xiaochen , Li Guangyu , Du Haifeng
Published: December 2024

The logic of collective action has laid a foundation for the research of public choice, and the success of collective action has been a long-term discussion when free-riding mechanism is considered in the dynamics. This study proposes a , which provides a novel dimension for explaining the logic of collective action. Under the framework, the accumulation of early social influence, conformity, and the pressure of relationship updating in small groups is discussed. The experiment results show that the accumulation of early social influence indirectly promotes the participants of collective action; conformity is conducive to stimulating collective action, but relies on the accumulation of early social influence; the pressure of relationship updating plays the small-group role, which promotes the participation of collective actions; all these effects are helpful in forming the cascade of cooperators, and prevent the coexistence of participants and non-participants of collective action.
The impact and freezing processes of a saltwater droplet on an ice surface
Authors: Lin Hongyi , Jin Zheyan , Yang Zhigang , Wu Yuan
Published: December 2024

In this study, the new findings of a low-concentration saltwater droplet impacting and freezing on an ice surface were presented for the first time. A detailed parameter study regarding the concentration of the saltwater and the temperature of the ice surface was carefully performed. Besides, the experiments with de-ionized water droplets were also carried out to make a comparison. The findings revealed that the maximum spreading factors of saltwater droplets decreased as the concentration of saltwater increased or the temperature of the ice surface decreased. When the saltwater droplets were freezing on the ice surface, some small protrusions might appear, which were different from the single pointy tip formed by the freezing de-ionized water droplet. Furthermore, as the concentration of the saltwater or the temperature of the ice surface decreased, the number of the protrusions increased, while the size of the protrusions decreased. In addition, the saltwater droplets were found to have a shorter freezing time and a lower freezing height than those of the de-ionized water droplets.
Paper-based lateral flow assays: Prediction of methanol content in alcoholic beverages
Authors: Behera Prateechee Padma , Mehta Sumit Kumar , Agarwal Kaushal , Bera Swapnanil , Arun Ravi Kumar , Mondal Pranab Kumar
Published: December 2024

This study introduces an innovative Grade 1 paper-based microfluidic device designed for the rapid, sensitive, and cost-effective detection of methanol in alcoholic beverages. The device integrates chemical reagents and sample fluid on a single paper strip, facilitating a straightforward and portable testing mechanism. The detection of methanol is achieved through a colorimetric reaction involving potassium permanganate, sulfuric acid, sodium bisulfite, and chromotropic acid. Upon interaction with methanol, the reagent mixture produces a distinct color change to purple, which can be visually assessed or quantified. The device works well with small sample volumes (usually less than 50 μl), making it ideal for field applications with minimal resources. The experimental validation confirmed that the device can detect methanol concentrations ranging from 5% (v/v) to 30% (v/v). This range of detection encompasses the critical concentrations found in contaminated alcoholic beverages responsible for methanol poisoning. In addition, numerical simulations were conducted at various time intervals for methanol concentrations, leading to the development of a colorimetric index specifically for measuring alcohol concentration ranging from 5% to 30% (v/v). Furthermore, experiments on both branded and locally made alcoholic beverages validated the accuracy of our developed colorimetric index. This paper-based technology provides various benefits compared to conventional methods, such as lower expenses, simplicity of operation, and the possibility of large-scale manufacturing and distribution in areas with limited resources.
Particle dynamics at fluid interface by pseudo-potential lattice Boltzmann method coupled with smoothed profile method
Authors: Hu Wei , Lin Tao , Yang Caihao , Tu Chengxu , Li Xiaolong , Xu Fei , Bao Fubing , Gao Xiaoyan , Zhang Yaning
Published: December 2024

Fluid–solid coupling widely exists in some natural phenomena and industrial applications. However, it is still an important challenge to correctly capture the transient changes of particles at fluid interface. We develop a lattice Boltzmann model for particle dynamics at fluid interface, which adopts a coupling strategy by combining the pseudo-force (Shan-Chen) multiphase multicomponent model and the smoothed profile method. In the coupling strategy, a novel extrapolation boundary condition is applied for fluid–solid interface, a repulsive force (bounce-back force) between solid node and fluid node is introduced in the coexistence region (at the fluid–solid interface), to form the interaction between fluid and solid particle. Thanks to the proposed fluid–solid coupling method, the drag force on solid particles can be correctly described, especially for situations of high solid volume fractions. It is found that the wetting angle θ between fluid interface and particle surface is basically linear with the repulsive force coefficient difference ΔG. What is more, to further validate the reliability of our proposed model, we performed two groups of simulations for different Bos = 0.51 (0.84) and 0.83 (1.35), they are the single particle trapped under gravity at deformed fluid interface and the falling single particle impacts fluid interface in the presence of gravity, respectively, and good agreements between simulation results and experimental ones in the description of the relationship between the inertial force and the interfacial tension are obtained, and their correlations are both close to 1, which proves the reliability of our proposed model.