bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic vortices in a highly anisotropic ferromagnet with unit spin
Authors: Ivanov B. A. , Kichizhiev A. N. , Sheka D. D.
Published: February 2025

It is shown that in a ferromagnet with unit spin, in which the average value of spin is small in view of its quantum contraction, the dynamics of a two-dimensional soliton (vortex) is quite different from that in a Heisenberg magnet. The vortex freezing and gyroeffects emerge only in a magnetic field, while the dynamics is Lorentz invariant in the absence of a field.
Point-contact spectroscopy of the organic superconductor β-(BEDT-TTF)2I3
Authors: Kamarchuk G. V. , Khotkevich A. V. , Kozlov M. É. , Pokhodnya K. I.
Published: February 2025

Homo- and heterojunctions (with Cu and Ag) of the organic superconductor β-(BEDT-TTF)) 2I3 in the normal state are investigated. The IVC of point contacts and their second derivatives (point-contact spectra) are measured in the voltage range 0–250 mV. Two types of point contact spectra are observed. The first type includes the curves displaying peculiarities in the entire voltage range under investigation. The second type is characterized by low-frequency peaks associated with the vibrations of the I3 anion. The point-contact spectra are compared with the optical reflection and absorption spectra. It is found that the nonlinearities observed in the high-voltage region are due to a significant contribution to the point-contact spectrum from the interaction between charge carriers and intermolecular vibrations. The obtained results point towards the possibility of investigating the intramolecular vibrations by the point-contact spectroscopy technique.
Determination of emf at a metal surface using point contacts
Authors: Kolesnichenko Yu. A. , Kulik I. O.
Published: February 2025

We have calculated the emf at the surface of a metal in which a steady-state nonequilibrium electron state is produced. The emf profile at the faces of a thin plate is studied theoretically for the case in which nonequilibrium electrons are injected into the metal from the current point contact. It is shown that this distribution contains information concerning the metal Fermi surface.
High-frequency properties of layered conductors in strong magnetic field
Authors: Peschanskii V. G. , Bek H. Kheir , Savel’eva S. N.
Published: February 2025

Dependence of the impedance of a layered conductor with quasi-two-dimensional electron energy spectrum on the incident wave polarization is studied theoretically. At certain orientations of the strong magnetic field H the penetration depth of the ac electric field along the normal n to the layers reveals narrow spikes as a function of the angle between the H and n vectors. Their experimental investigation will enable detailed analysis of the properties of electric-charge carrying elementary excitations in layered conductors.
Singularity of the coexistence curve diameter for HD near the critical point and “quantum effects”
Authors: Shimanskaya E. T. , Shimanskii Yu. I. , Oleinikova A. V.
Published: February 2025

The experimental data available in literature on the temperature dependence of the HD coexistence curve diameter are approximated by using the extended scaling equation with free exponents and amplitudes. Simultaneously, the values of the critical density are refined. The best approximation corresponds to a two-term equation with the value β1 = 0.70±0.12 for the exponent of the asymptotic term of the curve diameter and the value β3 ≈ 2β1 for the correction term. It is shown that the incorrect values of the critical density determined in experimental works could possibly be responsible for the “peculiar” behavior of the coexistence curve diameter of HD, which is associated with the emergence of quantum effects.
Josephson current and thermoelectric phenomena in superconducting point contacts
Authors: Kulik I. O. , Omel’yanchuk A. N.
Published: February 2025

The stationary Josephson effect has been studied in a nonequilibrium system, i.e., a superconducting point contact with different temperatures at its edges. The current–phase relation and the critical Josephson current have been found. The heat flux and thermo-emf of the contact have been calculated as periodic functions of the phase difference of the order parameter.
Critical currents of superconducting vanadium twist deformed at 4.2 K
Authors: Sokolenko V. I. , Starodubov Ya. D.
Published: February 2025

We studied effect of a twist deformation at 4.2 K on the change of the critical current density jc over a wide range of magnetic fields. In relatively weak fields, a decrease of jc is found with increasing shear deformation, which we ascribe to enhanced thermomagnetic instability in plastic strain localization areas.
Vibrational spectra and the nature of thermal broadening of light absorption bands of HTS compounds YBa2Cu3O7–x
Authors: Kachur I. S. , Kurnosov V. S. , Peschanskii A. V. , Piryatinskaya V. G. , Shapiro V. V. , Usoskin A. I. , Chukanova I. N.
Published: February 2025

The optical absorption spectrum of YBa2Cu3O6.15 films is investigated in the energy range 1.5–3 eV at temperatures from 4.2 to 300 K. A strong coupling (∼0.1 eV) between the electron excitation with a charge transfer and optical phonons is established. The main contribution to the electron excitation scattering comes from optical vibrations at frequencies of 330 and 150 cm−1, i.e., from vibrations of oxygen and copper ions in the Cu–O plane.
Antiferromagnetic resonance in Nd2CuO4
Authors: Blinkin V. A. , Pashkevich Yu. G. , Eremenko V. V. , Zvyagin S. A. , Pishko V. V.
Published: February 2025

The antiferromagnetic resonance in a “plane cross” four sublattice exchange-noncollinear structure is considered theoretically for different orientations of the magnetic field along the symmetry axes of the crystal and under different assumptions concerning the initial crystal symmetry and the intensities of exchange and relativistic interactions. The antiferromagnetic resonance spectra for possible types of behavior of the magnetic subsystem of copper ions in Nd2CuO4 are calculated and the fields of spin-reorientation transitions are presented. The results of calculations of the magnetic resonance spectrum are compared with the experimental data.
Temperature variation of the electron phase relaxation time in thin films
Authors: Kashirin V. Yu. , Komnik Yu. F.
Published: February 2025

Temperature dependences of inelastic relaxation time are obtained from the values of magnetoresistance of thin Bi films (∼ 100 Å) measured in the region of realization of weak electron localization effect. The physical nature of the temperature T0 separating the regions in which either electron-electron, or electron-phonon scattering dominates is discussed.
Theory of order–disorder phase transitions with over-the-barrier motion
Authors: Kovarskii V. L. , Sukharevskii B. Ya.
Published: February 2025

An approximate method taking into account the over-the-barrier motion in the two-well model of structural order-disorder transition is developed. The approximation consists in a transition to the energy representation and in the replacement of exact values of dynamic variables by the values averaged over one-particle phase trajectories. The problem is reduced to a three-component model in which two states describe motion in the wells, while the third corresponds to the over-the-barrier region. The temperature and barrier height are the parameters of the effective field determining the relative population of the over-the-barrier states. The main results include the nonlinear dependence Tc(J) of the transition temperature on the pair interaction constant, the dependence of Tc on the parameters of the barrier, and a sharp increase in the share of over-the-barrier states when Tc is approached from below, which corresponds to pre-transition defreezing of the low-temperature phase dynamics.
Thin films of bismuth-antimony alloy with a dielectric coating of variable thickness
Authors: Akhmedov S. Sh. , Brandt N. B. , Kashirin K. N. , Shvedkov E. I.
Published: February 2025

Semiconducting films of the alloy Bi–Sb (containing 11% Sb) and Bi films of a fixed thickness (300, 600, 900, 1200, 1500 Å) with a thin insulating layer of variable thickness (20–4 500 Å) (silicon dioxide, lithium fluoride) are investigated. An oscillating dependence of the resistance of films on the thickness of the insulating coating is observed.
Magnetic circular dichroism in YBa2Cu3O7–x films
Authors: Mil’ner A. A. , Kharchenko N. F. , Miloslavskaya O. V. , Pugachev A. T. , Stetsenko A. N. , Chirkin A. N.
Published: February 2025

Magnetic circular dichroism (MCD) has been detected in YBa2Cu3O7–x films in the visible spectral range from 1.5 to 4.5 V (275–825 nm). The MCD spectrum correlates with the absorption spectrum, and its magnitude attains values up to (1–5)·10−4 T−1 at the extremal points. Superconducting and nonsuperconducting samples display different kinds of dispersion and temperature dependences of MCD. For all the investigated samples, the magnetic field dependence of MCD has the form aH+b right up to 7 T, where the coefficient a depends on the temperature and wavelength at which observations were made, while the constant b is equal to zero within the error 2 · 10−5.
Characteristics of metal point contacts (PC) in the range between acoustic and optical frequencies
Authors: Balkashin O. P. , Kulik I. I.
Published: February 2025

The response of clean copper–copper point contacts to electromagnetic radiation is studied in the frequency interval 103–4.75 · 1014. Using the theory of point-contact spectroscopy, we have calculated the signal response developed in the contact when a bias voltage is applied to it. It is shown that, at frequencies up to ∼ 4.3 · 1012 Hz, the response is due to the rectification of the rf current at the nonlinear singularities of the current-voltage characteristic of the contact. At frequencies higher than ∼ 2.8 · 1013 Hz, the response mechanism is associated with the heating of the contact and contact region of the bulk electrodes by the incident radiation.
Amplification of spin waves by the field of a strong electromagnetic wave in antiferromagnetic semiconductors
Authors: Gnedkov V. P.
Published: February 2025

The effect of spin wave amplification by a high-frequency electric field in antiferromagnetic semiconductors is considered. In contrast to the case of a constant electric field, high drift velocities of charge carriers are not required for the realization of this effect.
Magnetic skyrmion: from fundamental physics to pioneering applications
Authors: Mishra Kishan K. , Lone Aijaz H. , Srinivasan Srikant , Fariborzi Hossein , Setti Gianluca
Published: February 2025

Skyrmionic devices exhibit energy-efficient and high-integration data storage and computing capabilities due to their small size, topological protection, and low drive current requirements. So, to realize these devices, an extensive study, from fundamental physics to practical applications, becomes essential. In this article, we present an exhaustive review of the advancements in understanding the fundamental physics behind magnetic skyrmions and the novel data storage and computing technologies based on them. We begin with an in-depth discussion of fundamental concepts such as topological protection, stability, statics, and dynamics essential for understanding skyrmions, henceforth the foundation of skyrmion technologies. For the realization of CMOS-compatible skyrmion functional devices, the writing and reading of the skyrmions are crucial. We discuss the developments in different writing schemes such as STT, SOT, and VCMA. The reading of skyrmions is predominantly achieved via two mechanisms: the magnetoresistive tunnel junction TMR effect and topological resistivity. So, a thorough investigation into the skyrmion Hall effect, topological properties, and emergent fields is also provided, concluding the discussion on skyrmion reading developments. Based on the writing and reading schemes, we discuss the applications of the skyrmions in conventional logic, unconventional logic, memory applications, and neuromorphic computing, including a model of a skyrmion-based SNN architecture achieving over 90% accuracy on MNIST and fashion-MNIST datasets. Furthermore, we outline the potential of skyrmion-hosting Majorana zero modes in emerging topological quantum computation and helicity-dependent skyrmion qubits.
Deep photonic reservoir computing based on a distributed feedback laser array
Authors: Zhou Changdi , Mu Penghua , Huang Yu , Yang Yigong , Zhou Pei , Lau Kuenyao , Li Nianqiang
Published: February 2025

Photonic reservoir computing (RC) is emerging as a competitive candidate for ultra-fast and energy-efficient neuromorphic computing, noted for its physical compatibility and straightforward training process. However, this widely appreciated form of machine learning typically employs only a single hidden layer with a feedback loop (FL), which essentially constrains the capability for complex task processing and poses challenges to integration. Here, we present an integrated deep photonic RC setup based on a distributed feedback laser array. This setup eliminates the dependence of the FL through the pre-processing termed quasi-convolution coding (QC), where the QC-based RC (QRC) significantly reduces the complexity of the network under the ensured performance. In particular, we extend this QRC into an on-chip deep structure, where this deep QRC (DQRC) exhibits remarkable superiority to its shallow counterparts. We demonstrate the augmented capabilities of DQRC through both simulations and experimental comparisons with QRC, extreme learning machine, and time-delay RC in time-dependent tasks. Moreover, the proposed deep configuration also excels in static image processing. We confirm the potential for simplifying the hardware implementations of deep neural networks, revealing a promising solution to satisfy the urgent demand for high-integration brain-inspired systems.
Programming universal unitary transformations on a general-purpose silicon photonic platform
Authors: Rausell-Campo José Roberto , Pérez-López Daniel , Capmany Francoy José
Published: February 2025

General-purpose programmable photonic processors provide a versatile platform for integrating diverse functionalities on a single chip. Leveraging a two-dimensional hexagonal waveguide mesh of Mach–Zehnder interferometers, these systems have demonstrated significant potential in microwave photonic applications. Additionally, they are a promising platform for creating unitary linear transformations, which are key elements in quantum computing and photonic neural networks. However, a general procedure for implementing these transformations on such systems has not been established yet. This work demonstrates the programming of universal unitary transformations on a general-purpose programmable photonic circuit with a hexagonal topology. We detail the steps to split the light on-chip, demonstrate that an equivalent structure to the Mach–Zehnder interferometer with one internal and one external phase shifter can be built in the hexagonal mesh, and program both the triangular and rectangular architectures for matrix multiplication. We recalibrate the system to account for passive phase deviations. Experimental programming of 3 × 3 and 4 × 4 random unitary matrices yields fidelities >98% and bit precisions over five bits. To the best of our knowledge, this is the first time that random unitary matrices are demonstrated on a general-purpose photonic processor and pave the way for the implementation of programmable photonic circuits in optical computing and signal processing systems.
Highly transparent and semi-transparent perovskites and their applications
Authors: Wallach Tehila , Etgar Lioz
Published: February 2025

Perovskite has recently garnered significant attention as a promising semiconductor for optoelectronic applications and particularly for solar cells. In various applications, solar cells must be semi-transparent or even nearly fully transparent. Perovskite solar cells emerge as strong contenders to meet this requirement, owing to their remarkable versatility that allows for high transparency. Consequently, numerous studies on semi-transparent perovskite have been presented in recent years, demonstrating significant advancements in their properties. This review aims to explore color-neutral highly transparent and semi-transparent perovskite solar cells, encompassing their synthetic routes, challenges associated with their fabrication process, and potential solutions. The incorporation of potential additives or two-dimensional perovskites to enhance the properties of semi-transparent perovskite solar cells is also discussed. Finally, we will delve into some promising applications of semi-transparent perovskite solar cells and other applications that have been successfully studied.
Computational wide-field imaging of poplar embolism and wound-response with a deployable microscope
Authors: Ingold Alexander , Darci-Maher Nicholas , Yang Edison , Sorenson Reed , Sieburth Leslie , Groover Andrew , Menon Rajesh
Published: February 2025

Low-cost, minimally invasive microscopy for tracking cellular dynamics in living plants within their natural ecosystems is crucial for addressing fundamental questions in plant ecology and biology. However, existing solutions are constrained by coarse resolution, limited field-of-view (FoV), and poor deployability in natural settings. Here, we utilize a compact, portable microscope (“miniscope”) for label-free (autofluorescence) imaging in living poplar wood. We systematically implement and evaluate multiple computational methods to enhance resolution and FoV. Our optimal computational pipeline, comprising maximal intensity projection, deconvolution, and flat-field correction, increases resolution by up to 39% on-axis and up to 49% at the field edges, resolving features of 2.87 μm, averaged over a FoV of ∼1 mm (diameter), compared with a 4.34 μm baseline. We demonstrate microscopy within the tissue of a living poplar plant in our greenhouse, observing the embolism of vessel elements, wound response, and tissue deformation from moisture evaporation.
Magneto-mechanical effects in a flexible magnetic system studied through combined MOKE magnetometry and mechanical testing
Authors: Ben Mahmoud H. , Girodon-Boulandet N. , Haboussi M. , Cazes F. , Renault P.-O. , Faurie D. , Zighem F.
Published: February 2025

We explore the magnetic properties of a thin Co film deposited on Kapton® substrates using the magneto-optical Kerr effect in a longitudinal configuration. We developed a magnetometer integrated with a tensile testing machine to investigate magnetization reversal phenomena under applied strain. The tensile machine, custom-designed to fit the experimental constraints, applies uniaxial stress to the samples, facilitating the study of magnetoelastic effects. Calibration using digital image correlation ensures accurate strain measurements. Our findings demonstrate that the application of strain significantly influences the magnetization curves, highlighting the emergence of anisotropies and changes in coercive and saturation fields.
Electronic structure and performance analysis of a pentagraphene based thermoelectric generator
Authors: Girma Mulgeta , Wakjira Tadesse Lemma , Hussien Kedir , Tadele Kumneger , Kelil Seyfan
Published: February 2025

This study investigated the potential of pentagraphene (PG) as a high-performance thermoelectric material for energy conversion applications. Electronic structure calculations revealed that PG is an indirect bandgap semiconductor with a bandgap energy of 2.11 eV and exhibits anisotropic dielectric and plasmon properties. The phonon dispersion calculation shows that the material is dynamically stable under small perturbations. Furthermore, compared with graphene, PG has a lower phononic thermal conductivity. Thermoelectric property calculations show that PG has a significantly higher figure of merit (ZT) of 0.15 at 300 K than graphene, with a ZT of 0.009. Moreover, the ZT of PG increases with temperature, reaching 0.52 at 900 K. Simulations of a PG-based thermoelectric generator (TEG) demonstrate an efficiency of 7% at a heat source temperature of 900 K. This finding suggests that PG possesses thermoelectric properties superior to those of graphene and holds significant potential for the development of more efficient and practical TEGs, particularly for applications requiring moderate temperatures.
Joint intelligent optimization design of the active region and electron blocking layer for AlGaN-based deep ultraviolet LEDs
Authors: Wang Jinglei , Lu Huimin , Ma Jianhua , Zhu Yifan , Zhang Zihua , Yu Tongjun , Wei Xuecheng , Yang Hua , Wang Jianping
Published: February 2025

Aiming to enhance the internal quantum efficiency (IQE) of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs), the active region based on the V-shaped quantum well (QW) and the electron-blocking layer (EBL) structure are jointly optimized using intelligent algorithms in this work. This method focuses on maximizing the IQE of the DUV LEDs by optimizing the geometric and material parameters of multiple QWs (MQWs) and EBL. It is demonstrated that the DUV LED with an optimized structure exhibits smaller band edge tilt for improved wave function overlap in QWs and more effective carrier blocking for reduced electron overflow compared to that with a conventional structure. The results show that, by optimizing the active region and EBL structure using the proposed method, the IQE and maximum radiation intensity of the AlGaN-based DUV LED are enhanced by 38% and 41% at 200 A/cm2 injection current density, respectively.
Analysis of the bias affecting the interpolated DFT frequency estimator
Authors: Belega Daniel , Petri Dario
Published: February 2025

In this paper, an analytical expression for the overall bias of the complex-valued noisy sine wave frequency estimator returned by the interpolated discrete Fourier transform algorithm is derived. That bias is due to the effect of both the algorithm intrinsic approximation when rectangular windowing is adopted and wideband noise. The effect of the number of analyzed samples and the signal-to-noise ratio on the ratio between the overall estimation bias and the estimator standard deviation is also investigated. In addition, leveraging on the derived expression, a frequency estimator that compensates for the contribution due to the algorithm intrinsic approximation is proposed and its accuracy is compared with that of the classical frequency estimator.
Interaction of upper hybrid waves with dust-ion-magnetoacoustic waves and stable two-dimensional solitons in dusty plasmas
Authors: Lashkin Volodymyr M. , Cheremnykh Oleg K.
Published: February 2025

We obtain a two-dimensional (2D) nonlinear system of equations for the electrostatic potential envelope and the low-frequency magnetic field perturbation to describe the interaction of the upper hybrid wave propagating perpendicular to an external magnetic field with the dust-ion-magnetoacoustic (DIMA) wave in a magnetized dusty plasma. The equations contain both scalar and vector nonlinearities. A nonlinear dispersion relation is derived, and the decay and modulation instability thresholds and growth rates are obtained. Numerical estimates show that instability thresholds can easily be exceeded in real dusty plasmas. In the static (subsonic) approximation, a 2D soliton solution (ground state) is found numerically by the generalized Petviashvili relaxation method. The perturbations of the magnetic field and plasma density in the soliton are nonmonotonic in space, and, along with the perturbation in the form of a well, there are also perturbation humps. Such peculiar radial soliton profiles differ significantly from previously known results on 2D solitons. The key point is that the presence of a gap in the DIMA wave dispersion due to the Rao cutoff frequency causes the nonlinearity to be nonlocal. We show that due to nonlocal nonlinearity the Hamiltonian is bounded below at fixed energy, proving the stability of the ground state.
Extended T2 times of shallow implanted NV in chemically mechanically polished diamond
Authors: Tyler S. , Newland J. , Hepworth P. , Wijesekara A. , Gullick I. R. , Markham M. L. , Newton M. E. , Green B. L.
Published: February 2025

Mechanical polishing of diamond is known to be detrimental to the spin coherence time and strain environment of near-surface defects via intrinsic introduction of subsurface damage: this damage is typically removed by inductively coupled plasma reactive ion etching (ICP-RIE). By utilizing a chemical mechanical polishing (CMP) process to prepare ⟨001⟩ diamond surfaces, we demonstrate that we can achieve 13C-limited spin lifetimes of shallow implanted (≤34 nm) nitrogen vacancy (NV) centers in an industrially scalable process. We compare spin lifetimes (T2) of three diamonds processed with CMP with one processed by ICP-RIE and observe an increased median T2 of 340 μs in the CMP-processed samples for 15NV centers implanted and annealed under identical conditions.
Confidence evaluation for feature selection in expanded feature space based on density of states
Authors: Obinata Koki , Igarashi Yasuhiko , Nagata Kenji , Sodeyama Keitaro , Okada Masato
Published: February 2025

In materials informatics, feature selection and model selection are utilized in the knowledge extraction process, and the confidence evaluation of the selection result is crucial for ensuring the reliability of the extracted knowledge. In this study, we propose a novel method to quantitatively evaluate the significance of low-dimensional models obtained from an expanded feature space using the density of states (DoS) for the evaluation metrics. This method allows us to compare the performance of the selected model to those of other models and evaluate its significance. We further propose an evaluation method for feature importance based on marginal posterior probabilities using the Bayesian model averaging (BMA) framework, which considers all models. We demonstrate the effectiveness of our proposed methods through their application to a crystal structure dataset. Our results show that the DoS analysis reveals the presence of a large number of models with a comparable performance with the best model reported in a previous research work. This suggests that knowledge extracted from a single selected model can be unreliable and that considering other models is crucial. We also show that the BMA-based feature importance evaluation provides valuable insights into the importance of features, highlighting both primary features and functional forms. In addition, we demonstrate that the LASSO + L0 method commonly used in existing research deteriorates the search space for model selection. Our findings suggest that our proposed methods provide valuable tools for assessing the significance of low-dimensional models and extracting knowledge from large-scale data in materials informatics.
Cross-correlations in the fluctuation–dissipation relation influence barrier-crossing dynamics
Authors: Wolf Niklas , Klippenstein Viktor , van der Vegt Nico F. A.
Published: February 2025

The Generalized Langevin Equation has been successfully used to model and understand the conformational dynamics of molecules in solution. However, recent works have demonstrated that, in these kinds of applications, the usual fluctuation–dissipation relation connecting the statistics of the random force to the memory kernel could contain a cross-correlation term. In this work, we systematically explore the origins of this cross-correlation term and argue that it plays a role, particularly in the folding dynamics of biopolymers. Finally, we propose an approximation for the cross-correlation term within the usual fluctuation–dissipation relation.
Spin–lattice relaxation mechanism of magnetic field effects on singlet fission in amorphous molecular semiconductors
Authors: Shushin A. I.
Published: February 2025

Singlet fission (SF) in molecular semiconductors is a photophysical process of spontaneous splitting of the excited singlet state into a pair of triplet excitons (TT-pair). This process is usually strongly influenced by spin-selective back geminate TT-annihilation (TTA). Spin selectivity manifests itself in magnetic field effects (MFEs) on both TTA and SF kinetics, the study of which allows us to reveal some specific features of this kinetics. In our work, we analyze the mechanism of MFE generation in TTA and SF processes in amorphous molecular semiconductors. In this mechanism, the MFEs are assumed to be determined by magnetic field dependent spin–lattice relaxation (SLR) in TT-pairs, generated by the zero-field splitting interaction (in T-excitons), fluctuating due to T-exciton hopping over arbitrarily oriented molecules in amorphous semiconductors. The SLR-transitions are described with a semiempirical model, which makes it possible to obtain the SF-kinetic functions in analytical form. The mechanism of SLR-assisted MFEs is found to be very efficient in TTA and SF processes. The obtained results are analyzed in detail and applied to interpret experimentally observed SF-kinetic dependences in various magnetic fields. In particular, it is shown that the proposed model of SLR-generated MFEs enables one to describe the effect of crossing of SF-kinetic functions, corresponding to different magnetic fields.
Investigation on high-temperature thermal conductivity in YTaO4 ceramics via 3-Omega method
Authors: Wang Shuaiqi , Zhang Hongmeng , Cheng Yi , Cao Qian , Gao Yixuan , Zhu Haiqiang , Huang Hongrui , Yang Hao , Ji Yanda
Published: February 2025

Thermal barrier coatings are essential for enhancing the performance and efficiency of high-performance systems, such as aerospace engines and gas turbines, by providing thermal protection at high temperatures. This study investigates YTaO4 ceramic, a material with notable high-temperature stability, low thermal conductivity, and strong corrosion resistance, making it a promising alternative for thermal barrier coatings. However, precise measurement of YTaO4’s thermal conductivity under high-temperature conditions poses a significant challenge. To address this, we employed the 3-Omega method, a transient technique well-suited for accurately measuring thermal conductivity across a wide temperature range from 300 to 700 K. The results indicate a decreasing trend in thermal conductivity with increasing temperature, exhibiting YTaO4’s potential as a high-temperature thermal barrier coating material with superior thermal insulation properties. This study not only demonstrates the utility of the 3-Omega method for characterizing thermal properties at high temperatures but also highlights its value for advancing research in high-performance materials tailored for thermal management in advanced engineering applications.
Application and prospect of vacuum freeze drying technology in environmental field
Authors: Liao Qingdan , Yu Dahua , Li Xitong
Published: February 2025

Vacuum freeze-drying (VFD) technology has gained extensive application across various sectors, particularly in environmental applications, where it is primarily utilized for the fabrication of environmental functional materials and the conservation of environmental organisms. This technology is applicable to soil enhancement, the remediation of aquatic pollutants, energy storage in thermoelectric materials, and the preservation of bacterial cultures. This review synthesizes the most recent advancements in VFD technology within the environmental domain, elaborating on its technical fundamentals, operational procedures, practical applications, and distinctive benefits. Furthermore, the article explores the prospective development trajectory and potential challenges for this technology in the environmental sector, offering scientific guidance for its continued application and insights into its innovative progression.
On the early stagnation point during transient acoustic cavitation
Authors: Al Bishtawi B. , Mustapha K. B. , Scribano G.
Published: February 2025

We explore an acoustofluidic phenomenon, in an aqueous environment, of an emerging early stagnation point that consistently positions itself at a distance of two times the ultrasonic horn tip diameter 2D, regardless of the tip size. This was initially captured numerically in a two-dimensional domain of horn-type reactors of diameters D = 3, 6, 13, and 16 mm in a 107 × 50 mm cuvette. We deduced that the axial extension of the bubble cluster influences the rate of decay of axial flow; however, it does not affect the stagnation point. Cavitation attenuation was scrutinized by mathematically modeling the time-averaged axial flow during the cavitation transient state and solving the flow using Newman's subroutine. During fast streaming, acoustic force attenuation α decreases exponentially at a maximum rate of ≈1.70 with the doubling of Reynolds number Re. However, an inverse trend was demonstrated by the dimensionless attenuation Γ=−2αD, as it increased by a factor of ≈1.28. Similarly, Γ exponentially increased with the doubling of Re during slow streaming suggesting direct proportionality between Γ and Re. This emphasized the underlying role of the term 2D in amplifying attenuation induced by morphing structures of inertial bubble clusters. Moreover, tracking the bubble population along the horn axis revealed that mushroom-like structures formed under small horn tips have a linear bubble distribution, while cone-like structures under larger tips maintained an exponential distribution. This may suggest that a linear distribution may enhance attenuation and justify the aforementioned trends.
New insights into the comparison of diffusion models and their impacts on gas extraction in coal seams
Authors: Xu Hexiang , Zhai Cheng , Cheng Zhongwu , Liu Ting , Xu Jizhao , Zheng Yangfeng , Chen Aikun
Published: February 2025

Diffusion is a crucial factor governing gas migration within coal seams. The particle method is mainly used to test the gas diffusion coefficient. However, selecting the appropriate particle size for diffusion coefficient determination remains challenging. Although various diffusion models have been proposed to fit experimental data accurately, their impact on gas extraction simulations is still unclear. In this study, gas diffusion experiments were conducted on nine samples with varying particle sizes, and parameters for four diffusion models were calculated by solving the inverse problem using numerical methods. Four numerical simulations of gas extraction were subsequently performed using these parameters. Finally, a calculation method for determining the time nodes to enhance gas extraction was proposed. Results showed that the gas desorption ratio initially decreased and then stabilized as particle size increased. The representative elementary volume size of coal particles for gas diffusion was 0.83–1.7 mm. Except for classical unipore diffusion model, other diffusion models could effectively fit the experimental data. Among these, time-dependent diffusion model is more suitable for predicting the gas pressure within coal seams and gas production. However, this requires establishing a quantitative relationship between laboratory test results and field-scale simulation parameters. The concept of equivalent extraction resistance was introduced to determine the time nodes for enhanced gas extraction, which were found to be necessary when daily production decreased to 14.47%–21.73% of the initial value. The research findings are of great significance for bridging laboratory results with practical field applications.
Circadian clock control of interactions between eIF2α kinase CPC-3 and GCN1 with ribosomes regulates rhythmic translation initiation
Authors: Preh Ebimobowei O. , Ramirez Manuel A. , Mohan Sidharth , Guy Chanté R. , Bell-Pedersen Deborah
Published: February 2025

Misregulation of the activity of GCN2, the kinase that phosphorylates and inactivates translation initiation factor eIF2α, has been implicated in several health disorders, underscoring the need to determine the mechanisms controlling GCN2 activation. During nutrient starvation, increased uncharged tRNA levels trigger GCN1 and GCN20 proteins to mediate the binding of uncharged tRNA to GCN2 to activate the kinase to phosphorylate eIF2α. Under constant conditions, activation of the
Neurospora crassa
homolog of GCN2, CPC-3, is controlled by the circadian clock. However, how the circadian clock controls the rhythmic activity of CPC-3 was not known. We found that the clock regulates CPC-3 and GCN1 interaction with ribosomes and show that these interactions are necessary for clock regulation of CPC-3 activity. CPC-3 activity rhythms, and the rhythmic interaction of CPC-3 and GCN1 with ribosomes, are abolished in a temperature-sensitive valyl-tRNA synthetase mutant (

un-3
ts

) that has high levels of uncharged tRNA
Val
at all times of the day. Disrupting the interaction between GCN1 and uncharged tRNA in the absence of GCN20 altered rhythmic CPC-3 activity, indicating that the clock controls the interaction between uncharged tRNA and GCN1. Together, these data support that circadian rhythms in mRNA translation through CPC-3 activity require rhythms in uncharged tRNA levels that drive the rhythmic interaction between CPC-3 and GCN1 with ribosomes. This regulation uncovers a fundamental mechanism to ensure temporal coordination between peak cellular energy levels and the energetically demanding process of mRNA translation.
Human MAIT cell response profiles biased toward IL-17 or IL-10 are distinct effector states directed by the cytokine milieu
Authors: Boulouis Caroline , Mouchtaridi Elli , Müller Thomas R. , Mak Jeffrey Y. W. , Fairlie David P. , Bergman Peter , Michaëlsson Jakob , Halfvarson Jonas , Mjösberg Jenny , Buggert Marcus , Sandberg Johan K.
Published: February 2025

Mucosal-associated invariant T (MAIT) cells are unconventional T cells that mediate rapid antimicrobial immune responses to antigens derived from microbial riboflavin pathway metabolites presented by the evolutionarily conserved MR1 molecules. MAIT cells represent a large pre-expanded T cell subset in humans and are involved in both protective immunity and inflammatory immunopathology. However, what controls the functional heterogeneity of human MAIT cell responses is still largely unclear. Here, combining functional and transcriptomic analyses, we investigate how MAIT cell response programs are influenced by the cytokine milieu at the time of antigen recognition. Activation by MR1-presented antigen together with IL-12 induces intermediate levels of IFNγ and TNF, as well as a regulatory profile with substantial IL-10 production and elevated expression of TIM-3, LAG-3, and PD-1. Activation by the combination of antigen and IL-12 induces a c-MAF-dependent program required for IL-10 production. The MAIT cell-derived IL-10 mediates both autocrine and paracrine immune regulation. In contrast, coactivation of MAIT cells with IL-18 induces IL-17, GM-CSF, IFNγ, and TNF, without IL-10. Notably, IL-18 dominantly counteracts IL-10 expression. The activation states biased toward IL-10 or IL-17 production are reversible and do not represent stable subsets. Finally, MR1-restricted TCR-mediated activation without cytokine coactivation drives primarily granzyme B cytolytic arming. Altogether, these findings demonstrate that human MAIT cells adapt their functional effector response during antigen recognition to cytokine cues in the microenvironment, and identify programs biased toward either regulatory c-MAF-dependent IL-10 expression, or an inflammatory IL-17 and GM-CSF profile.
Linguistic hegemony in academia
Authors: Allaithy Ahmed , Zaki Mai , Khaldi Boutheina , Al-Kaisi Meis
Published: February 2025

This research paper addresses the complex interplay between multilingualism and the pervasive dominance of the
English language in academic publishing, particularly focusing on Arabic academic publications in the humanities. This study
adopts a comprehensive research methodology, employing both qualitative and quantitative analyses to investigate Arabic research
representation in English-dominated academic journals, particularly those indexed in Scopus across various humanities disciplines
such as Language and Linguistics, Literature, Islamic Studies, and Translation. The analysis utilizes bibliometric data from
Scopus, focusing on publications from 1970 to 2023 that feature “Arabic,” “Arab,” or “Islamic” in their titles, abstracts, or
keywords. The results indicate a significant underrepresentation of Arabic scholarship, with English accounting for 85% of
publications and Arabic barely reaching 1.1%. The discrepancies in publication trends are obvious, on the levels of countries,
author affiliations as well as language of publication. Overall, the results highlight the hegemonic nature of academic
publishing, the marginalization of valuable Arabic research and the challenges Arabic-speaking scholars face in gaining
recognition. Finally, the study addresses the broader implications of linguistic dominance on global knowledge production and
advocates for a more inclusive scholarly landscape that values linguistic diversity through specific recommendations.
Pulmonary Arterial Compliance and the FREEDOM-EV study
Authors: Davis Brittany NJ , Champion Hunter C
Published: February 2025

This video explains pulmonary arterial compliance, its relevance in pulmonary arterial hypertension, and how oral treprostinil improves PAC in PAH.
On the partial volume effect in magnetic particle imaging
Authors: Good Hayden J , Sanders Toby , Melnyk Andrii , Mohtasebzadeh A Rahman , Imhoff Eric Daniel , Goodwill Patrick , Rinaldi-Ramos Carlos M
Published: February 2025

Objective. Magnetic particle imaging (MPI) is an emerging tomographic ‘hot spot’ imaging modality with potential to visualize superparamagnetic iron oxide nanoparticle tracer distributions with high sensitivity and quantitative accuracy. MPI shares many similarities with positron emission tomography (PET), where the partial volume effect (PVE) can result in signal under- and over-quantification due to spill-over of signal arising from limited resolution. While the PVE has been alluded to in the MPI literature it has not been previously studied nor characterized. The objective of this study was to systematically characterize this PVE in MPI. Approach. This contribution characterizes the PVE using models of varying size and shape filled with a uniform concentration of tracer. The effect of object size on signal distribution was analyzed after application of a new image post-processing filter. Main results. As object size increased, signal distribution increased to a maximum signal value independent of object geometry and proportional to tracer concentration. Furthermore, for small objects with characteristic dimensions below the resolution of the tracer at the scanning conditions used, signal suppression was observed. These results are consistent with foundational observations of PVE in PET, suggesting that approaches to overcome the PVE in PET may be applicable to MPI. Significance. This finding has significant impact on the MPI field by demonstrating the presence of the PVE phenomenon that can directly influence imaging results.
FLANet: A multiscale temporal convolution and spatial-spectral attention network for EEG artifact removal with adversarial training
Authors: Wang Junkongshuai , Luo Yangjie , Wang Haoran , Wang Lu , Zhang Lihua , Gan Zhongxue , Kang Xiaoyang
Published: February 2025

Objective. Denoising artifacts, such as noise from muscle or cardiac activity, is a crucial and ubiquitous concern in neurophysiological signal processing, particularly for enhancing the signal-to-noise ratio in electroencephalograph (EEG) analysis. Novel methods based on deep learning demonstrate a notably prominent effect compared to traditional denoising approaches. However, those still suffer from certain limitations. Some methods often neglect the multi-domain characteristics of the artifact signal. Even among those that do consider these, there are deficiencies in terms of efficiency, effectiveness and computation cost. Approach. In this study, we propose a multiscale temporal convolution and spatial-spectral attention network with adversarial training for automatically filtering artifacts, named filter artifacts network (FLANet). The multiscale convolution module can extract sufficient temporal information and the spatial-spectral attention network can extract not only non-local similarity but also spectral dependencies. To make data denoising more efficient and accurate, we adopt adversarial training with novel loss functions to generate outputs that are closer to pure signals. Main results. The results show that the method proposed in this paper achieves great performance in artifact removal and valid information preservation on EEG signals contaminated by different types of artifacts. This approach enables a more optimal trade-off between denoising efficacy and computational overhead. Significance. The proposed artifact removal framework facilitates the implementation of an efficient denoising method, contributing to the advancement of neural analysis and neural engineering, and can be expected to be applied to clinical research and to realize novel human-computer interaction systems.
Unifying Special Relativity and Quantum Mechanics via Adynamical Global Constraints
Authors: Stuckey W.M. , Silberstein Michael
Published: February 2025

Maxwell unified the disparate concepts of electric and magnetic fields with one theory (electromagnetism) and Einstein then unified the disparate theories of electromagnetism and mechanics with one kinematics (Minkowski space of special relativity). In this talk, we will briefly explain how the disparate kinematics of quantum mechanics (finite-dimensional Hilbert space) and special relativity can be unified with one principle (relativity principle). This result follows from the axiomatic reconstruction of quantum mechanics via information-theoretic principles, which has successfully recast quantum mechanics as a principle theory a la Einstein, i.e., the formalism of the theory follows from an empirically discovered fact, just like special relativity. According to the quantum reconstruction program, the empirically discovered fact whence the Hilbert space formalism of quantum mechanics is Information Invariance & Continuity. Of course, the empirically discovered fact whence the Lorentz transformations of special relativity is the light postulate, i.e., everyone measures the same value for the speed of light c, regardless of their relative motions. Obviously, the light postulate can be justified by the relativity principle—the laws of physics are the same in all inertial reference frames—because c is a constant of Nature per Maxwell’s electromagnetism. [We label this “NPRF + c” for short, where NPRF stands for “no preferred reference frame.”] As we will show, Information Invariance & Continuity can also be justified by the relativity principle by first spatializing the quantum reconstruction program’s operational notion of measurement. In that case, Information Invariance & Continuity entails the empirically discovered fact that everyone measures the same value for Planck’s constant h, regardless of their relative spatial orientations or locations (Planck postulate). Since Poincar’e transformations relate inertial reference frames via spatial rotations and translations as well as boosts, and h is a constant of Nature per Planck’s radiation law, the relativity principle justifies the Planck postulate (NPRF + h) just like it justifies the light postulate (NPRF + c). Thus, the kinematics of quantum mechanics and special relativity are unified in that both follow most fundamentally from the relativity principle in the adynamical global constraints NPRF + h and NPRF + c. This approach provides a principle solution to the mystery of quantum entanglement that does not violate locality, statistical independence, intersubjective agreement, or the uniqueness of experimental outcomes and it does not alter quantum mechanics as a principle theory. An ontology consistent with this unification is introduced and we deflate both the ‘big’ and ‘small’measurement problems.