bluuebunny/crossref_metadata_2025 huggingface dataset:
Impurity electron-magnetic states in a semiinfinite magnetically ordered crystal
Authors: Petrova T. G.
Published: January 2025

Electron–magnon states localized at donor magnetic impurities in a semiinfinite magnetic material are studied on the basis of the microscopic s−d model. The energies of these states are found for cases when the impurity is located at the surface, in the first surface layer, and inside the crystal. We consider the effect of the impurity on the spectrum of single-magnon excitations of the system. The contribution of the surface to the magnon energy distribution function is shown to be always positive in the low-frequency region of the spectrum and to decrease with increasing defect concentration. This causes the low-temperature average magnetization per surface atom to increase upon doping, but this value is always lower than the average magnetization per atom in the bulk of the system. The results are supported by the experimentally observed behavior of the surface magnetization of the compound EuO at low temperature.
Electronic structure and magnetic properties of the intermetallic compound TiCo
Authors: Grechnev G. E. , Svechkarev I. V.
Published: January 2025

A theoretical study has been carried out of the electronic structure and thermodynamic characteristics of the compound TiCo in the low-temperature region. The nature of the stability of this compound has been established. It has been shown that there is a strong exchange enhancement of the spin susceptibility in TiCo. The reasons for the existence of strong paramagnetism and superconductivity in TiCo have been found. The parameters of the electron–phonon and electron–paramagnon interactions have been determined.
Energy gap in superconductors with A-15 structure
Authors: Aleksandrov A. S. , Balankin A. S. , Parshakov A. E.
Published: January 2025

The effect of the fine structure of the electron density of states N(ξ) on the magnitude of the ratio 2Δ(z)Tc in narrow-gap superconductors is studied on the basis of a model with a peak in the density of states N(ξ) near the Fermi level. It was established experimentally that the drop in Tc in defective samples of Nb3Sn from 17.7 to 13.9 K is accompanied by a decrease in 2Δ(0)/Tc from 4.0 to 3.6. This result agrees well with the theoretical estimates made.
Mechanism of high-temperature oscillations of the magnetoresistance in semimetals
Authors: Bogod Yu. A. , Gorelik L. Yu. , Slutskin A. A.
Published: January 2025

An explanation is proposed for the “high-temperature” quantum oscillations of the transverse conductivity of semimetals. It is shown that these oscillations have a qualitatively different nature from the Shubnikov–de Haas oscillations: they are determined by the singular points of the energy spectrum of the semimetal, which, generally speaking, do not coincide with the Fermi energy; the relative contribution of electrons with such “deep” energies is determined, contrary to the traditional viewpoint, not by the temperature smearing of the Fermi distribution function, but rather by the “collisional” broadening of the electron energy levels, caused both by elastic and inelastic electron relaxation processes.
Slow relaxation of nuclear magnons in antiferromagnets with defects
Authors: Safonov V. L.
Published: January 2025

The slow relaxation of spin waves in a two-level system is shown to be applicable to the description of experimental results on the rate of nuclear-magnon relaxation as a function of the temperature, frequency, and wave vector.
Determination of the elastic scattering length of carriers in point contacts
Authors: Ass E. I. , Gribov N. N.
Published: January 2025

The resistance of a bismuth point contact has been studied as a function of the magnetic field. The results are in good agreement with theoretical calculations for the magnetoresistance of dirty point contacts and make it possible to determine the electron elastic scattering length li in the region of the contact. The values of li obtained from the quadratic and linear segments of the dependence R(H) coincide and amount to 10−4−10−5 cm.
High-temperature superconductivity of metal-oxide ceramics
Authors: Moiseev L. P. , Uvarova S. K. , Frolova V. S. , Chernyakhovskii A. É.
Published: January 2025

We have investigated the superconductivity of BaPb1−xBixO3 + Ag interstitial solid solutions with x < 0.45. We find that in silver-doped samples with x = 0.45 superconductivity appears at a critical temperature Tc ∼ 10 K, whereas in the pure material there is a dielectric gap and semiconductor-like electrical conductivity. We have also reproduced the high-temperature superconductivity results in the systems La−Ba−Cu−O and La−Sr−Cu−O. We discuss the close connections between these metal-oxides and some possible reasons for the high Tc.
Anomalous behavior of the elastic modulus in La1.8Sr0.2CuO4
Authors: Gaiduk A. L. , Zherlitsyn S. V. , Panfilov A. S. , Puzikov V. M. , Stepanenko A. M. , Fil’ V. D. , Chernyi A. S.
Published: January 2025

We have observed a significant (up to 10%) reduction in the longitudinal and transverse sound velocities in the ceramic La1.8Sr0.2CuO4. The reduction is detectable in the temperature range 200−40 K and indicates that the system is approaching a structurally unstable state.
Structural transition in a two-dimensional Wigner crystal interacting with an elastic medium
Authors: Vol E. D. , Kukushkin L. S.
Published: January 2025

We have investigated a two-dimensional Wigner crystal whose electrons interact strongly with an elastic medium. We show that an external magnetic field exceeding a certain critical value and perpendicular to the crystal plane causes a structural transition in this system. Our calculation employs the simplest version of the self-consistent field method. We obtain the dependence of the critical magnetic field on the system characteristics and derive an expression from the energy gained as a result of the spontaneous breakdown of symmetry. The critical magnetic field is of the order 105–106 Oe in systems expected to exhibit the effect.
Nonlinear wave interactions on the surface of superfluid helium
Authors: Pushkina N. I.
Published: January 2025

The linear reflection of second sound from the surface of superfluid 4He bounded by vacuum is investigated with allowance for surface excitations. The results are used to analyze two nonlinear problems. The first nonlinear problem is the phase conjugation of second sound by the surface of superfluid 4He. An expression is obtained for the phase-conjugated wave at the boundary, and the conversion efficiency is estimated. The second nonlinear problem is the excitation of surface second-sound waves by bulk second-sound waves in superfluid solutions of 3He in 4He. An equation is derived for the amplitude of the generated surface waves. The exciting-wave intensity at which the surface second-sound waves acquire an appreciable amplitude is estimated.
Electric-field microstructure and surface-electron binding energy in helium with short-range order
Authors: Vil’k Yu. M. , Monarkha Yu. P.
Published: January 2025

We investigate the influence of correlation effects in a two-electron system on the electron binding energy and lifetime in a nonequilibrium pressing field E1<E1(0). Within the framework of the harmonic lattice model we determine the microstructure of the electric field above the two-dimensional electronic liquid and we find the correlation correction to the binding energy of surface electrons as a function of their concentration and the drop in the pressing field. This approach allowed the deformation effects in the electron system (compression of a correlation hole) to be taken into account sufficiently. It is shown that under real conditions this correlation correction can substantially exceed the electron binding energy in an ideal system. The theoretical results are compared with the available experimental data. We discuss how electron heating due to the drop in the field affects the electron lifetime in a two-dimensional electron system, in different states.
Nuclear spin waves in disordered magnets with competing anisotropy
Authors: Sinitsyn E. V. , Ivanov S. I. , Bostrem I. G.
Published: January 2025

The frequencies of spin excitations in the nuclear subsystem of ferro- and antiferromagnets with a competing uniaxial anisotropy are determined. It is shown that under the conditions of large fluctuations of the anisotropy constant there can exist collective spin modes, corresponding to periodic changes in the variance of the orientational fluctuations of the magnetic moments. The characteristic features of NMR in the system involved in spin-orientational transitions are studied.
Phenomenological theory of the relaxation of spin waves in the multisublattice antiferromagnet UO2
Authors: Bar’yakhtar V. G. , Belykh V. G. , Vitebskiĭ I. M. , Soboleva T. K.
Published: January 2025

The relaxation of optical and acoustic magnons in the multisublattice, noncollinear, antiferromagnet UO2 is studied phenomenologically, employing the equation of motion of the sublattice magnetizations. It is shown that the relaxation of optical magnons is determined by the uniform exchange interactions. The damping Pi (i = 1,2,3) of each of the three acoustic branches of the magnon spectrum is represented in the form Γi=B/2λrel +λexq2+λ1ωsi2/4BL02, where ωsi is the frequency of the corresponding branch of the spectrum, and the quantities B and λ1 are of an exchange nature.
Electronic structure of iron digermanide
Authors: Skriver H. L. , Grechnev G. E. , Kruglov V. O. , Svechkarev I. V.
Published: January 2025

The electronic structure of iron digermanide was studied theoretically by the LMTO method. It was established that a sharp peak is present in the electronic density of states at the Fermi level as well as distinct p–d hybridization in the conduction band. It is shown that strong exchange-induced amplification of the spin paramagnetism occurs in FeGe2. The characteristics of the de Haas–van Alphen effect in iron digermanide are explained qualitatively.
Upper limit on the resistance of superconducting oxides
Authors: Svistunov V. M. , Permyakov V. V. , Revenko Yu. F. , Tarenkov V. Yu.
Published: January 2025

By measuring current attenuation in ring-shaped samples of La–Sr–Cu–O (LSCO) and Y–Ba–Cu–O (YBCO) we have determined that the resistivity ρ ≤ (2 ± 1)10−19Ω − m.
Electron transfer of local pairs in crystals and the superconductivity of metal-oxide compounds
Authors: Kulik I. O.
Published: January 2025

The hybridization of two-electron centers (local pairs) with conduction electrons in crystals results in a universal interaction between pairs. This mechanism effects the transfer of pairs between their localization sites even when the wave functions do not overlap directly. The transition to the ordered state is of the “superconducting glass” type. If the energy level of the pairs (per electron) lies above the Fermi level or is in the energy gap near the boundary of the occupied states, then the mechanism of “recurrent” superconductivity is possible.
Theory of quantum diffusion in solid hydrogen. II. Fluctuation approach
Authors: Strzhemechnyĭ M. A. , Tokar’ O. I.
Published: January 2025

The kinetics of clusterization of orthoexcitations in solid parahydrogen is studied based on the previously proposed fluctuation mechanism, in which the migrating particle is exposed to a time-dependent field generated by surrounding scatterers with internal degrees of freedom. The different types of interaction of orthoimpurities with ortho-singles and pairs are analyzed and evaluated. It is shown that, along with direct electrical quadrupole interaction, there also exists an indirect interaction, which is of approximately the same intensity and due to the quadrupole dilatation of the lattice surrounding a pair cluster. The expression obtained for the probability of a hop is analyzed for different limiting cases. Estimates of the relaxation times, following from the proposed theory, agree well with the estimates observed experimentally. At low temperatures and for low concentrations, the clusterization time is an increasing function of the temperature. Analysis of the theoretical answers suggest that the clusterization kinetics is more likely to be determined by almost free diffusion of singles (or pairs) rather than by the last hop prior to pair formation.
Effect of composition and pressure changes on the magnetic properties of Kondo lattices CeSi2−xGax
Authors: Moshchalkov V. V. , Petrenko O. V. , Semenov M. V. , Lutsiv R. V. , Babich O. I.
Published: January 2025

The variation of the magnetic properties as a function of the composition x was studied for the Kondo lattices CeSi2−xGax (0.1 ≤ x ≤ 1.3) with a structure of the α-ThSi2 type. It is established that the temperature of the transition from the paramagnetic state into the ferromagnetic state equals TM ≃ 10 K and is virtually independent of the gallium concentration in the interval 0.1 ≤ x ≤ 0.7. For compositions with x > 0.9, a sharp drop was observed in TM (x), and for x > 1.1 the compounds CeSi2−xGax are not magnetic. The effect of pressure P up to 16 kbar on the value TM was studied and the pressure derivative dTM/dP ≃ 0.13 K/kbar was determined for the compound CeSi1.3Ga0.7.
Thermodynamic properties of two-band superconductors with narrow band close to the Fermi level
Authors: Galaiko V. P. , Bezuglyi E. V. , Shumeiko V. S.
Published: January 2025

The behavior of the superconducting order parameter Δ(T) and specific heat of a two-band superconductor with narrow band near the Fermi level is considered for a wide range of temperatures and electron concentrations. The characteristic features of the calculated dependence of Δ(T), which are in qualitative agreement with experimental data on high-temperature superconductors, are a high value of 2Δ(0)/Tc and a small (as compared to the BCS theory) values of Δ(T)/Δ(0) for 0< T < Tc. A nonmonotonic temperature dependence of specific heat of the two-band superconductor at T < Tc is predicted.
The effect of a closed back cavity on air-coupled piezoelectric micromachined ultrasonic transducer performance
Authors: Gong Yi , Liu Miaojie , Gong Shaobo , Li Quanning , Chen Xuejiao , Pang Wei , Zhang Menglun
Published: January 2025

In conventional piezoelectric micromachined ultrasonic transducers (PMUTs), the backside acoustic energy is often used inefficiently, resulting in up to half of the energy being wasted. Vacuum encapsulation can improve the energy utilization efficiency, but this technique is not compatible with state-of-the-art devices such as cantilever-based PMUTs. A closed back cavity provides an alternative method for effectively utilizing the backside acoustic energy. This paper investigates the effects of a closed back cavity on PMUT performance through theoretical analysis, simulations, and experimental verification. Increasing the cavity depth produces a periodic modulation of several key PMUT metrics, such as the relative frequency deviation and quality factor. The optimal cavity depth for PMUTs that ensures a robust resonant frequency and high quality factor is defined as a function of the acoustic wavelength. A closed back cavity also provides an effective method for continuously tuning the quality factor, and thus the bandwidth, of PMUTs. This work paves the way for air-coupled PMUTs with adjustable performance for various applications.
Ultra-fast single-crystal CVD diamonds in the particle time-of-flight (PTOF) detector for low yield burn-history measurements on the NIF (invited)
Authors: Reichelt B. L. , Kishimori R. , Lawrence Y. , Wink C. W. , Johnson M. Gatu , Johnson T. M. , Adrian P. J. , Baker K. L. , Casey D. T. , Clark D. S. , Dannhoff S. G. , Eckart M. J. , Evans T. E. , Geppert-Kleinrath H. , Gibson D. , Hahn K. D. , Higginson D. P. , Izumi N. , Kabadi N. V. , Kerr S. , Kunimune J. H. , Landen O. L. , Mariscal E. , Marsh R. A. , Martinez D. , Meaney K. D. , Pearcy J. A. , Petrasso R. D. , Rubery M. S. , Rusby D. R. , Russell L. , Schlossberg D. J. , Smalyuk V. A. , Tommasini R. , Frenje J. A. , Li C. K.
Published: January 2025

The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond-based detector and is the only diagnostic for measuring nuclear bang times of low yield (<1013) shots on the National Ignition Facility. Recently, a comprehensive study of detector impulse responses revealed certain detectors with very fast and consistent impulse responses with a rise time of <50 ps, enabling low yield burn history measurements. At the current standoff of 50 cm, this measurement is possible with fast 14 MeV neutrons from deuterium–tritium (DT) fusion plasmas. PTOF-inferred DT burn width numbers compare well with widths inferred from the gamma reaction history diagnostic on mid-yield (1013–1015) shots, where both systems are capable of making this measurement. These new capabilities could be extended to 2.5 MeV deuterium–deuterium neutrons from D plasmas and to even lower yield by reducing the detector standoff distance to 10 cm; a design for this is also presented.
The investigation of specific absorption rate measurement system for intelligent connected vehicles and its uncertainty analysis
Authors: Zhou Xin , Shen Qingfei , Pang Xinhua , Yao Yao , Tang Wei , Zhang Yan , Huo Hongyan , Wu Tong
Published: January 2025

Radiation from wireless communication devices inside intelligent connected vehicles has been an expeditious growth of concern regarding possible adverse effects on human health. Due to the significant differences in the working scenarios compared to traditional mobile products, the traditional measuring systems of specific absorption rate (SAR) are not applicable to in-vehicle scenarios. This paper has developed a SAR measurement system and a SAR measurement method, which are suitable for in-vehicle scenarios. Since the measurement hardware and methods are significantly different from traditional systems, it is necessary to assess the measurement uncertainty for the new measurement system. Due to the significant influence of tissue fluid on the SAR, this paper focuses on analyzing the relationship between tissue fluid and SAR. Based on the validated electromagnetic simulation model, linear and quadratic fitting models reflecting the relationship between tissue fluid properties and SAR are established. Then, the uncertainty propagation was realized using both the Guide to the Expression of Uncertainty in Measurement and MCM (Monte Carlo Method) through these models. The results of uncertainty analysis were analyzed in combination with the fitting error. The results of the analyses show that the fitting error of the quadratic measurement model is smaller because there is no simple linear relationship between the tissue fluid properties and the SAR values, and thus, it is more reasonable to use the MCM method to evaluate the uncertainty.
Interlayer and intralayer magnetic interactions for room-temperature strong ferrimagnetism of layered organic–inorganic hybrid nanoplates
Authors: Kuang Qifeng , Zhang Bo , Dong Baojuan , Men Xiaoling , Yang Bing , Zhou Yangtao , Li Zhiwei , Shang Xiaolei , Yang Teng , Huang Jianqi , Li Da , Zhang Zhidong
Published: January 2025

In the past few decades, a development of organic magnets with room-temperature strong ferromagnetism is challenged by the difficulty of creating three-dimensional (3D) long-range magnetic orderings in organic materials at a temperature higher than room temperature. Here, we report room-temperature ferrimagnetism of a tetragonal organic–inorganic hybrid Fe14Se16(tepa)III (tepa = tetraethylenepentamine), where III represents a coordination of a tepa molecule with a Fe3+ ion for an organic complex. The layered hybrid in a nanoplate-like shape is formed by periodic incorporation of tetragonal β-Fe3Se4 inorganic layers and organic spacing layers consisting of tepa and Fe3+. Fe14Se16(tepa)III shows a saturation magnetization MS of 7.2 emu g−1 at 300 K and a record-high Néel temperature TN (>560 K) in the organic magnets reported experimentally. A Mössbauer spectrum confirms a 3D long-range magnetic ordering of Fe2+ [S = 2 (71.4%)] and Fe3+ ions [S = 5/2 (21.7%) and 1/2 (4.0%)] in β-Fe3Se4 layers and organic spacing layers of Fe14Se16(tepa)III,9. First-principles calculations explain that the 3D long-range antiferromagnetic interactions between interlayer and intralayer irons result in the strong ferrimagnetism of Fe14Se16(tepa)III. This study unveils the possibility of tuning magnetic couplings of interlayer and intralayer high-spin Fe3+ and Fe2+ for enhancing the ferrimagnetism of layered hybrids and, thus, for future room-temperature magnetic/spintronic applications.
Agent-based modeling of quantum prisoner’s dilemma
Authors: Benjamin Colin , Tah Rajdeep
Published: January 2025

What happens when an infinite number of players play a quantum game? In this paper, we will answer this question by looking at the emergence of cooperation, in the presence of noise, in a one-shot quantum prisoner’s dilemma (QuPD). We will use the numerical agent-based model (ABM) and compare it with the analytical Nash equilibrium mapping (NEM) technique. To measure cooperation, we consider five indicators, i.e., game magnetization, entanglement susceptibility, correlation, player’s payoff average, and payoff capacity, respectively. In quantum social dilemmas, entanglement plays a non-trivial role in determining the behavior of the quantum players (or qubits) in the thermodynamic limit, and for QuPD, we consider the existence of bipartite entanglement between neighboring quantum players. For the five indicators in question, we observe first-order phase transitions at two entanglement values, and these phase transition points depend on the payoffs associated with the QuPD game. We numerically analyze and study the properties of both the quantum and the defect phases of the QuPD via the five indicators. The results of this paper demonstrate that both ABM and NEM, in conjunction with the chosen five indicators, provide insightful information on cooperative behavior in an infinite-player one-shot quantum prisoner’s dilemma.
Liquid nitrogen pre-injection assisted fracturing in hot dry rock reservoirs
Authors: Zhou Chunbo , Su Shanjie , Liang Xin , Xue Yi , Cai Chengzheng , Gao Feng
Published: January 2025

Hot dry rock (HDR) is one of the clean geothermal energy sources to develop. Geothermal energy extraction from HDR targets depths shallower than 5 km and temperatures up to 400 °C. Creating artificially stimulated fractures allows fluids to extract geothermal energy in HDR. The high temperature and in situ stress of HDR pose challenges for conventional fracturing means. Injecting liquid nitrogen into HDR reservoirs will cause damage around the borehole. Liquid nitrogen pre-injection assisted nitrogen fracturing is expected to provide an efficient solution for reservoir stimulation. In this study, considering the thermodynamic properties of liquid nitrogen vary at different temperatures and pressures, a coupled thermo-hydro-mechanical-damage model is proposed. The proposed model is validated by comparison with a reference study. The effectiveness and parameter sensitivity of liquid nitrogen injection and the geological environment in altering the liquid nitrogen pre-injection method are investigated. The liquid nitrogen pre-injection is proved to promote the formation of complex fractures and reduce the breakdown pressures in subsequent nitrogen fracturing. Under high temperatures or low heterogeneity coefficients in reservoirs, liquid nitrogen pre-injection is more effective. Under high in situ stress ratios, liquid nitrogen pre-injection is more effective in promoting complex fractures in subsequent fracturing. Under low in situ stress ratios, liquid nitrogen pre-injection can significantly reduce the instability pressure of subsequent fracturing. The results contribute to the design of liquid nitrogen assisted fracturing for HDR reservoirs.
Pressure wave propagation characteristics and two-phase pressure drop in a long-distance pipeline–riser system
Authors: Cao Yeqi , Xu Qiang , Wang Chan , Yu Haiyang , Li Yuwen , Huang Bo , Guo Liejin
Published: January 2025

To ensure the flow safety of the offshore gathering pipeline system, it is critical to study the large-scale pressure wave propagation behavior and predict the two-phase pressure drop in the subsea pipeline. In this paper, the local flow structure, pressure wave propagation characteristics, and two-phase pressure drop of the horizontal pipeline are obtained in a long-distance pipeline S-shaped riser system with a diameter of 46 mm and a total length of 1722 m. The overall-local correlation flow pattern map in the pipeline–riser system is proposed. The propagation modes of the pressure wave induced by the riser's pressure fluctuation in the horizontal pipeline under different overall flow patterns are clarified, and the correlations for predicting the propagation velocity and the attenuation coefficient of the pressure wave are proposed. The correlation for predicting the two-phase pressure drop of long-distance horizontal pipeline in the pipeline–riser system is established, and 88.23% of the data are within the error interval of ± 10%.
Role of bulk viscosity on the flow physics past a rotating cylinder
Authors: Ankush  , Sengupta Bidesh , Singh Satyvir , Lawrence Raj Prince Raj
Published: January 2025

The present study investigates the impact of bulk viscosity on the complex flow dynamics past a rotating cylinder, with particular emphasis on compressible and non-equilibrium effects that emerge in nitrogen (N2) and carbon dioxide (CO2). By solving unsteady conservation laws obtained from the Boltzmann–Curtiss transport equation, the research focuses on key flow features such as vortex shedding, vorticity generation, enstrophy, kinetic energy dissipation, and the degree of thermal non-equilibrium. Numerical simulations are performed at a Mach number of 0.6 using the dbnsTurbFoam solver with unstructured meshes, and the computational model is verified using available data for flow past a rotating cylinder. The results reveal that bulk viscosity significantly affects vortex shedding, particularly suppressing vortex formation and reducing flow instability. In CO2, high bulk viscosity nearly eliminates vortex shedding, leading to a laminar wake, while in N2, vortex shedding is dampened but persists. Enstrophy and vorticity production through stretching and baroclinic effects are also reduced in both gases as bulk viscosity increases, with CO2 showing more dramatic reductions due to its higher inherent viscosity. The study further indicates that bulk viscosity enhances kinetic energy dissipation in both gases, with N2 exhibiting sharper dissipation than CO2. Additionally, the role of rotational speed is explored, showing that higher rotational speeds amplify vorticity production and energy dissipation. While high-speed rotation induces more turbulence and instability in N2, it stabilizes the flow in CO2, leading to a more organized wake. The findings demonstrate that bulk viscosity and rotational speed are crucial in controlling flow stability and energy dissipation, with significant variations depending on the gas properties.
Heat and mass transfer in conical gaps with disks rotating: An asymptotic analytical solution for high Prandtl and Schmidt numbers
Authors: Shevchuk Igor V.
Published: January 2025

This study focuses on an approximate analytical solution of the problem of laminar heat transfer of a fluid in a conical gap (rotating disk and a fixed cone) with small conicity angles up to 4° for high Prandtl numbers. A recently developed improved asymptotic expansion method for energy equation was applied. The characteristic Reynolds number Re took values of 0.1, 0.5, and 1.0, the Prandtl number Pr varied over a wide range from 1 to 3 × 106, whereas the exponent n* in the power law for the disk temperature was equal to 0 (isothermal disk) or 2 (quadratic increase along the radius). The new solution was obtained using a new expansion parameter SvT =  Re2Δ2Pr (a new dimensionless number first formulated here). This parameter involves the relative thickness of a thermal boundary layer Δ on the disk, which is less than the gap height. New approximate analytical solutions for the Nusselt numbers and the value of Δ on the disk are in good agreement with the self-similar solution. The exponent at the Pr and Re numbers are 1/3 and 2/3, respectively. These solutions are valid for SvT ≥ 7,…,7.65 (with the lowest values of Pr = 700). The boundaries of the solution for moderate Prandtl numbers can be extended to Sv ≤ 25, when the thermal boundary layer does not emerge on the disk (with the highest values of Pr = 2000). The new analytical solutions are advantageous in the analysis of experimental data on heat transfer for mineral oils, and in convective diffusion in electrochemistry.
Macrofungi of Two Peoples Bay Nature Reserve, Western Australia
Authors: Syme K. , Lebel T. , Hilton R. N.
Published: January 2025

Context Although fungi are an integral part of the environment, little is known about the diversity of macrofungi in the south-coast region of Western Australia. Aims We summarise the results of macrofungi surveys conducted over the past four decades and highlight some of the rare and interesting taxa from the Two Peoples Bay Nature Reserve. Methods We used herbarium records, Fungimap observations, and the results of several surveys (1991–1992, 1998–1999, 2006–2007, 2020), to compile a list of the macrofungi found in different locations and major habitats in the Reserve. Names have been updated to reflect modern taxonomic knowledge/classifications. Key results A total of 196 formally named species of macrofungi representing 144 genera from 58 families are reported. Ten species have been described based on material collected in the Reserve. The Inocybaceae (56 collections, 25 species) and Amanitaceae (149 collections, 20 species) were the most diverse families due to significant recent taxonomic work. The diversity in Cortinariaceae, Russulaceae, Boletaceae, and Entolomataceae was under-represented. The rare green Amanita austroviridis, and hypogeal Elaphomyces chlorocarpus and E. symeae are known from fewer than six herbarium records, most from the Reserve. Conclusions Due to the cryptic nature of many sporocarps and highly seasonal fruiting patterns, we believe the list provided here is perhaps 40% of the actual diversity present in the Reserve. Implications The presence of rare species, and high number of undescribed, but likely novel species in diverse lineages, supports the need for further investigation of the macrofungal diversity in the Reserve.
Fundamental constraints and questions from the study of Martian meteorites and the need for returned samples
Authors: Udry Arya , Ostwald Amanda M. , Day James M.D. , Hallis Lydia J.
Published: January 2025

Physical materials from planetary bodies are crucial for understanding fundamental processes that constrain the evolution of the solar system, as samples can be analyzed at high precision and accuracy in Earth-based laboratories. Mars is the only planet outside of Earth from which we possess samples in the form of meteorites. Martian meteorites (n > 350) have enabled constraints to be placed on various aspects of the red planet’s formation and evolution, notably: that Mars accreted and differentiated rapidly; that the planet has a complex volatile element evolution; and that it has always been volcanically active with a rich and diverse magmatic history. Meteorites have limitations, however, with lack of field context, restricted lithological diversity compared to the martian surface, and with no sampling of a major portion of Mars’ history between 4.1 and 2.4 billion years ago. Returned samples from Mars have the potential to fill these gaps and answer many open questions driven by the study of meteorites, as well as reveal new fundamental research questions. Key questions that Mars Sample Return is likely to answer regard the basic evolution of the martian interior and surface, its potential for habitability and the possibility of past life, and calibration of age dating of the martian surface. Samples of various lithologies and different ages collected at Jezero crater by the
Perseverance
rover will aid in better understanding our own planet and will answer outstanding questions regarding Mars’ future geological evolution and habitability.
Olfaction with legs—Spiders use wall-pore sensilla for pheromone detection
Authors: Talukder Mohammad Belal , Müller Carsten H. G. , Zhang Dan-Dan , Schulz Stefan , Löfstedt Christer , Wang Hong-Lei , Uhl Gabriele B.
Published: January 2025

The sense of smell is a central sensory modality of most terrestrial species. However, our knowledge of olfaction is based on vertebrates and insects. In contrast, little is known about the chemosensory world of spiders and nothing about how they perform olfaction despite their important ecological role. The orb-weaving spider
Argiope bruennichi
lends itself to an in-depth study on olfaction as it is one of the few spider species whose volatile sex pheromone, emitted by females to attract males, is known. We combined ultrastructural and electrophysiological analyses and found that previously overlooked sensilla with wall pores are abundant on all walking legs of
A. bruennichi
males. We compared the ultrastructure of these wall-pore sensilla with those known to perform olfaction in insects, exploring similarities and differences. Electrophysiological single sensillum recordings demonstrated that the wall-pore sensilla in
A. bruennichi
respond highly sensitive and in a concentration-dependent manner to the sex pheromone. Our study demonstrates male-specific sensilla for detecting signaling females, whereas females and subadult males are devoid of wall pore sensilla. In a preliminary comparative morphological analysis using 19 species from 16 spider families, we found that wall-pore sensilla occur in male spiders from most, but not in basally branching clades or in Salticids, suggesting that wall-pore sensilla evolved at least once within spiders and were lost at least once. This research significantly expands our knowledge of the sensory ecology of spiders, will stimulate studies on the diversity and function of sensilla, as well as studies on the evolution of olfaction in arthropods.
Co-creating stories with generative AI
Authors: Cheung Lok Ming Eric , Shi Huiwen
Published: January 2025

Publicly available Generative Artificial Intelligence (GenAI)
tools are said to liberate students from the instrumental use of English and
empower them to write creative texts to communicate with different communities.
This paper reports on an undergraduate language-related service-learning subject
in a Hong Kong tertiary institution. In the subject, students co-created digital
stories with asylum-seeking children, in written and podcast formats, with the
help of GenAI. The qualitative content analysis of semi-structured interviews
with the students found that this experience expanded the students’ creative
potential. Meanwhile, GenAI played a peripheral role in the story creation
processes, in that the students exercised agency to use the tools and remained
critical of the AI-generated content. This study argues that digital
storytelling with GenAI, when used critically, promotes linguistic, digital and
cultural awareness among ESL learners, offering them a third space to interact
with culturally diverse communities in Hong Kong and giving them genuine
ownership of English for creative and communicative purposes.
Exploring the official and unofficial paratexts of Chinese indie video games on Steam Pages
Authors: Moreno García Luis Damián
Published: January 2025

The present study explores Chinese indie video game Steam Pages focusing on two types of complementary epitexts on
the Steam platform: “official” paratexts, authored by game creators, and “unofficial” paratexts created by game players. The
functions of such official and unofficial paratexts are probed by following Batchelor’s authorial classification (2018). The paper applies the concept of paratexts to discuss the empowerment of
reviewers, curators and gamers and their texts (as paratexts) as essential components of the Pages, while attempting to cast light
onto creator-gamer interactions. Tentative findings include both reinforcing and contradicting cross-interactions between official
and unofficial paratexts, as well as differing functions that help shape Steam Pages into cohesive components inside Steam’s
social ecosystem.
Beyond inter- and transdisciplinarity
Authors: Morton Tom
Published: January 2025

While English-medium instruction (EMI) is growing rapidly as a field of practice, there is a lack of agreement around its conceptual and terminological boundaries, and its purposes are often ill defined. To deal with the complexity of the phenomena it addresses, it has been argued that EMI should adopt an interdisciplinary or transdisciplinary perspective. This conceptual article adopts a different position, arguing that EMI is best seen as an example of a “practical assemblage” (Pennycook, 2024), which draws on different epistemic resources to engage with its own set of problems, rather than vying to become a discipline in itself. Using the sociological lens of Legitimation Code Theory (Maton, 2014), the article proposes a framework for positioning EMI as an autonomous field of inquiry, addressing its own problem-situations and research questions. The analysis finds that, rather than building boundaries around itself, EMI as a practical assemblage would be better placed to open itself to ideas from other domains of enquiry while maintaining its autonomy in working on its own problems for its own purposes.
“We pursue justice”
Authors: Dehlsen Mark , Kalfagianni Agni , Sénit Carole-Anne
Published: January 2025

Philanthropic foundations are key players in global sustainability governance. This paper explores the
legitimation strategies these foundations use to justify their actions and positions in the sustainable development community. By
combining Theo van Leeuwen’s legitimation framework with our novel analytical justice framework, we offer a new tool to analyse
hard-to-research actors. Analysing data from 41 foundation websites, we find that foundations emphasize Global Egalitarian
Cosmopolitanism in their values and objectives to align with global sustainability discourses. However, Libertarian ideas dominate
when discussing programs and founders. This indicates there may be internal conflicts within foundations over the relationship
between extreme wealth accumulation required for global philanthropy and sustainability objectives. In turn, this has implications
for how foundations position themselves as agents of justice in sustainable development. While discourse analysis provides
valuable insights into philanthropic legitimation strategies, further research is needed to fully understand how justice
intersects with organizational decision-making.
Embodied vulnerability
Authors: Moriarty Máiréad
Published: January 2025

A recent move in semiotic landscape studies is to examine how those placed on the margins of society counteract
such regulation by using the semiotic landscape as a platform to enact regimes of voice and agency where scholarly attention has
begun to study the spatial representations of vulnerability and how individuals othered by these processes fight back (see for
example Milani & Levron, 2019; Moriarty,
2019). Drawing on Butler’s (2004) work on corporeal vulnerability, the aim
of this paper is to put forward embodied vulnerability as a useful lens for examining semiotic landscapes of
vulnerability. The aim of this paper is to put forward skinscape as a resource for embodied vulnerability through the prism of
youth suffering from suicidal behaviour in the Republic of Ireland. In drawing on a skinscape images and tattoo narratives, this
paper will show how those engaging in suicidal behaviours draw on tattoos as a form of embodiment of their vulnerability that
leads to healing and comfort.
Respuestas de los usuarios en páginas de turismo en Facebook
Authors: González García Virginia
Published: January 2025

Este artículo se propone una caracterización de la dinámica discursiva de las páginas de promoción turística en Facebook a partir de la estrategia comunicativa de la intensificación pragmática. A través de un análisis de corpus, se pretende estudiar el comportamiento que presenta este fenómeno en tres ciudades, Madrid, Sevilla y Valencia, para caracterizar empíricamente el comportamiento interactivo que se da entre los gestores de estas páginas y sus destinatarios. así como su función en el discurso del turismo en la red. De forma más específica, se indica qué tipo de comentarios o post tienen como resultado mayor interactividad y generan mayor presencia de intensificación por parte de los usuarios de Facebook. Los resultados del análisis realizado muestran que se pueden determinar comportamientos discursivos y pragmáticos que generan mayor respuesta por parte de los interlocutores así como un mayor uso de estrategias valorizadoras al servicio de la construcción y proyección de una imagen turística. Los patrones discursivos que más se acercan a los usos interpersonales y colaborativos propios de la red social Facebook son aquellos que obtienen mayor respuesta y con intensificación por parte de los receptores de estos comentarios.
Interrupciones y « voz propia »
Authors: Chi Huidong , Bestué Carmen , Vargas-Urpí Mireia
Published: January 2025

Este artículo presenta una innovadora propuesta metodológica para el análisis de las interacciones en juicios
penales con la intervención de intérpretes judiciales en la combinación chino-español. Los juicios fueron transcritos a partir de
las grabaciones oficiales en vídeo de los Juzgados de lo Penal de Barcelona. El objetivo es describir la metodología empleada para
identificar, categorizar y analizar las soluciones que los intérpretes adoptan ante problemas interaccionales. Se detallan las
categorías de anotación de estos problemas y se analizan las interacciones designadas como « voz propia » y las interrupciones,
distinguiendo si se consideran justificadas o no. Los resultados muestran una alta incidencia de voces propias injustificadas por
parte del intérprete, especialmente en intervenciones que obtienen información no solicitada por los operadores judiciales y en
las que el intérprete responde en lugar del declarante. Las interacciones injustificadas identificadas evidencian que los
intérpretes judiciales de chino incumplen la norma de imparcialidad prevista en la mayoría de los códigos deontológicos. Además,
la falta de reacción de los operadores judiciales sugiere un claro desconocimiento de la perspectiva interaccional de la
interpretación judicial por parte de los profesionales de la justicia.
La asimetría conceptual en la traducción del medio ambiente
Authors: Cabezas-García Melania , Fuentes-Pineda Teresa
Published: January 2025

La asimetría conceptual se produce cuando un concepto no se codifica del mismo modo en dos lenguas debido a diferencias culturales, entre otros factores, y puede dar lugar a la inexistencia de equivalencia en la lengua de llegada. Este trabajo investiga los problemas de traducción en la combinación lingüística francés>español derivados de la asimetría conceptual en el ámbito medioambiental, y propone soluciones adaptadas a diferentes situaciones comunicativas. Para ello, nos centramos en tres conceptos referidos a animales endémicos de Francia que no existen en España (chamois, bouquetin des alpes y sittelle corse). Con vistas a analizar estos conceptos y los términos empleados para nombrarlos en español, se compiló un corpus monolingüe en español que contiene textos especializados sobre estas tres especies animales. Por otro lado, empleamos dos clasificaciones con el fin de: (i) estudiar la variación terminológica presente en español y (ii) analizar las estrategias de traducción empleadas en los casos de inexistencia de equivalencia en la lengua de llegada.
Rank-deficient square-root information filter for unified GNSS precise point positioning model
Authors: Zheng Yanning
Published: January 2025

Numerous global navigation satellite system (GNSS) precise point positioning (PPP) models have been developed by reparameterizing the rank-deficient (RD) original model, which performs well under standard conditions. However, predefined reparameterization introduces challenges, such as incomplete satellite observation utilization and the complexity of modeling original parameters, whose solutions are often model-specific and lack unification. To address these issues, we propose the RD-square-root information filter (RD-SRIF) for processing RD observational problems. This approach enables a unified PPP model based on the original model constructed at runtime, facilitating universal solutions to challenges posed by predefined reparameterization. Theoretical analysis and experimental results demonstrate that the unified model matches the performance of classic models for normal observational conditions while offering several advantages. It effectively incorporates incomplete satellite observations to enhance ionosphere modeling, and ensures rigorous modeling of original parameters for improved failure detection in dynamic models and single-frequency PPP performance. Moreover, it surpasses classic models in addressing complex challenges, such as smartphone-based PPP. The unified PPP model makes it easier to solve the modeling problems of PPP, while the RD-SRIF may also be beneficial for other GNSS or non-GNSS algorithms.
Time-dependent billiards, variational method, and invariant tori
Authors: Zhang Xiaoming , Li Denghui , Liu Xianbin
Published: January 2025

In this work, we study the dynamics of two-dimensional convex billiards with time-periodically perturbed boundaries. Due to the non-conservation of the particle’s energy, the billiard map becomes a four-dimensional twist map. Rather than analyzing this high-dimensional twist map directly, we develop a novel variational approach to address this problem. Additionally, we present and prove a Lagrangian version of Moser’s twist map theorem in higher dimensions to support our variational method. As a result, we demonstrate the existence of invariant tori near the boundary of a convex billiard when the time-periodic perturbation is sufficiently small. In addition, for a time-periodic perturbed circular billiard, the invariant tori are not necessarily located near the boundary.