Browse Articles
Discover research articles across all indexed journals
Direct-potential fit of the K2 ground state in the entire bound, quasi-bound, and continuum energy range
Based on extensive experimental (spectroscopic) and theoretical (ab initio) information, the semi-empirical adiabatic potential of interatomic interaction has been constructed in analytical form for the electronic ground state of potassium dimer molecule K2. As the main massive of experimental input data, more than 15 000 lines of laser-induced fluorescence (LIF) A1Σu+−b3Πu→X1Σg+ progressions of 39K2 recorded by a high-resolution Fourier transform spectrometer with the accuracy of 0.001–0.002 cm−1 were used, which cover the entire bound and quasi-bound energy range up to the ground state dissociation threshold, in the range of vibrational quantum numbers vX = 0–82 and rotational quantum numbers JX = 1–149. More than 760 detected LIF lines have been referred to minor 39K41K and 41K2 isotopologues and used for an independent proof of mass-invariant properties of the constructed semi-empirical potential. In order to clarify the behavior of potential at long internuclear distances, the quasi-bound levels lying above the dissociation threshold were included, as well as the scattering lengths based on the positions of Feshbach magnetic resonances obtained in Tiemann et al. [Phys. Rev. Res. 2, 013366 (2020)]. The inner limb of the semi-empirical curve has been extrapolated above the experimental region by means of non-empirical interatomic potential calculated by a single-reference coupled-cluster CCSD(T)/CBS method. Two alternative continuous functions (CPE and MLR) were used for analytical approximation of the interatomic potential with a physically consistent extension into the continuum region. Both potentials appeared to be applicable in the whole bound, quasi-bound, and continuum range, allowing to avoid, at least within +/−0.002 cm−1 limit, the non-physical oscillation-like behavior, which appeared at reproduction of experimental LIF frequencies at using the analytical potential in Tiemann et al. [Phys. Rev. Res. 2, 013366 (2020)] and the molecular constants in the form of the Dunham polynomial in Amiot et al. [J. Chem. Phys. 103, 3350 (1995)].
Interrelations of work with health and wellbeing on a 50+ year old workforce assessed using longitudinal self-reports and actigraphy
Abstract Daily activities, work, and health are closely intertwined. We closely followed 45 participants aged 50–66 years working across different sectors in a year-long study, who completed a range of baseline, weekly, and monthly Participant Reported Outcome Measures (PROMs). Participants self-reported on work-related aspects using the Brief Job Stress Questionnaire (BJSQ) and Workplace Wellbeing Question Bank (WWQB); wellbeing using the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS); and sleep using the Pittsburgh Sleep Quality Index (PSQI). Additionally, they provided wrist-worn actigraphy data collected over three periods (each period ~ 35–40 days). In total, we collected 1901 PROMs entries and 5258 days of actigraphy data. We computed 55 actigraphy measures broadly assessing physical activity, sleep, and diurnal variability characteristics. We explored statistical associations between pairs of PROMs items and between PROMs items with actigraphy measures using correlations and cross-correlations to assess similarities. We built mixed-effects models to associate PROMs items and actigraphy measures with global PSQI and total WEMWBS. We found very strong associations (>|0.5|) between BJSQ items with total WEMWBS and global PSQI, highlighting certain work aspects affect sleep and overall wellbeing, whereas actigraphy analysis provided new insights uncovering sleep quality problems including disturbances and awakenings for most participants. Additionally, the mixed-effects models revealed that actigraphy-derived sleep measures are strongly associated with total WEMWBS and global PSQI providing complementary information to PROMs. Integrating longitudinal work-related self-reports and actigraphy can provide useful personalized wellbeing- and health-insights, and should likely be considered in future smart-health monitoring systems to promote healthy aging.
Glassy dynamics of LiCl · 6H2O solution in nanoporous media
Understanding how nanoconfinement alters the dynamics of glass-forming aqueous electrolytes is essential for clarifying the interplay among ionic hydration, hydrogen-bond structure, and interfacial effects. Here, LiCl · 6H2O was investigated in the bulk and under confinement in SBA-15 mesoporous silica with an average pore diameter of 8 nm. Differential scanning calorimetry, Raman spectroscopy, quasielastic neutron scattering, 1H spin–lattice relaxation, and pulsed-field-gradient nuclear magnetic resonance (NMR) were combined to probe thermal behavior, hydrogen-bond structure, local mobility, and translational transport over complementary time and length scales. The calorimetric results show that LiCl · 6H2O remains glass-forming under confinement, while its thermal signature of the glass transition becomes slightly broader and shifts upward relative to the bulk. Raman spectra in the O–H stretching region indicate that the concentrated LiCl solution possesses a weakened and less tetrahedrally connected hydrogen-bond network compared with bulk water. On the sub-nanosecond timescale, elastic fixed-window analysis reveals reduced mean-squared displacements under confinement, demonstrating suppressed motional amplitudes inside the pores. Inelastic fixed-window neutron scattering scans analyzed within a jump-diffusion framework yield lower effective translational diffusion coefficients and longer residence times for the confined liquid, indicating that confinement mainly hinders translational escape from transient local environments. 1H relaxometry further shows that confinement broadens the distribution of local proton fluctuation times, while PFG-NMR confirms that the measured long-range water mobility in bulk LiCl · 6H2O solution is reduced relative to bulk water. While the present data do not resolve distinct interfacial and pore-centered populations in confined LiCl · 6H2O, its dynamics are markedly altered across timescales, from the glassy to the liquid state, resulting in slower, spatially constrained, and more heterogeneous motions.
Airworthiness compliance assessment of GPS RAIM/FDE availability and outage characteristics with barometric aiding across multiple flight phases under RTCA DO-401
Inelastic processes in state-resolved transport theory: Application to oxygen mixtures
The accurate prediction of transport properties in strongly nonequilibrium flows using the State-to-State approach requires reliable state-resolved collision integrals. In the present study, a self-consistent Variable Hard Sphere Statistical Inelastic Cross Section (VHS-SICS) model is constructed to treat elastic and rotationally inelastic collision cross sections within a unified analytical framework, with vibrationally inelastic cross sections incorporated through the forced harmonic oscillator with free rotation model. Two independent sets of VHS parameters are determined by fitting separately to quasiclassical trajectory reference data for the diffusion-type and viscosity-type collision integrals, achieving good agreement over a wide temperature range. The rotationally inelastic contribution to the collision integrals is found to grow significantly with temperature and vibrational excitation, with the Boltzmann-averaged ratio reaching a maximum of ∼1.3, and the effect being notably stronger for O2–O collisions than for O2–O2 collisions. The rotational energy diffusion collision integral Ωcirot,dk(1,1) is evaluated within the VHS-SICS framework for the O2/O system and is found to remain numerically close to the standard diffusion collision integral. The vibrationally inelastic contribution to the collision integrals is negligible throughout the temperature range considered. For the transport coefficients of O2/O mixtures, rotationally inelastic effects lead to reductions in both shear viscosity and thermal conductivity, with the influence growing monotonically with temperature and being most pronounced at an atomic oxygen mole fraction of xO = 50%. The rotational energy diffusion correction is found to have a negligible influence on the thermal conductivity. The present VHS-SICS model provides a reliable and self-consistent framework for the accurate prediction of transport properties in nonequilibrium oxygen-containing flows.
Experts outperform novices under high attentional load in soccer referees: a multiple object tracking study
Abstract This study investigates the differences in visual attention between expert and novice soccer referees using a multiple object tracking (MOT) task, with a specific focus on how tracking speed modulates these differences. Fifty-two male referees were divided into expert (currently holding international/national level, n = 26) and novice (currently holding level 1 or below, n = 26) groups. Participants completed an MOT task at three tracking speeds (4°/s, 8°/s, and 12°/s), with accuracy recorded and analyzed via a 2 (Group: expert vs. novice) × 3 (Speed: 4°/s, 8°/s, 12°/s) mixed-design repeated-measures analysis of variance (ANOVA), with Speed as the within-subjects factor and Group as the between-subjects factor. Results showed a significant main effect of tracking speed, F (2, 100) = 451.364, p < 0.001, η P 2 = 0.900, with accuracy decreasing as speed increased, and a main effect of expertise, F (1, 50) = 12.406, p < 0.001, η P 2 = 0.199, with experts outperforming novices. Crucially, a significant Group × Speed interaction was observed, F (2, 100) = 10.096, p < 0.001, η P 2 = 0.168: experts demonstrated superior performance at higher speeds (8°/s and 12°/s), but no significant difference was found at the lowest speed (4°/s). Post-hoc analyses with Bonferroni correction revealed large effect sizes for the group differences at 8°/s ( Cohen’s d = 0.935) and 12°/s ( d = 1.164), whereas the effect at 4°/s was negligible ( d = 0.172). These findings suggest that expert soccer referees show superior MOT performance under higher attentional load, indicating a load-dependent expertise advantage.
A universal model for predicting the stability of complexes with rare earths and trivalent actinides
Despite significant interest in rare earth and actinide complexes, experimental characterization is challenging due to element scarcity, cost, and safety requirements, while accurate quantum chemical modeling remains computationally intractable for relevant system sizes. We overcome these barriers by introducing a novel machine learning architecture. Trained on available experimental data spanning multiple f-block elements, our model achieves significantly improved predictive accuracy for complex stability. Analysis of its applicability domain and fragment contributions reveals critical structural determinants of stability.
A computer vision-based approach to monitor changes in ecosystems associated with marine renewable energy projects
Abstract To assess the potential ecological effects of marine renewable energy (MRE) devices, it is essential to establish a baseline of ecosystem conditions prior to disturbance and to monitor throughout the installation, operation, maintenance, and decommissioning phases. The design of mitigation and compensation measures depends on the difference between baseline conditions and the impacted ecosystem. In this study, we develop and evaluate a semi-automated methodological proof-of-concept using computer vision to assess environmental changes around MRE devices. Using fish monitoring as a case study, we reduced image processing time by eliminating empty frames and detecting fish in the remaining frames. Species identification was carried out by experts using a public database for comparative analysis. We also conducted an identification exercise for a single fish species and tested a monocular depth-estimation method (3D reconstruction from 2D images) to measure distances between organisms and devices. Finally, we propose a potential methodological framework for integrating computer vision across the life cycle of MRE devices to monitor both natural and anthropogenic processes, including space colonization, trophic interactions, pollution, and the effects of underwater structures. The merits and drawbacks of the approach are discussed.
ClSO4 in Venus sulfur–chlorine chemistry: Radical localization, vibrational signatures, and near-UV/visible spectrum
Venus photochemistry couples SO2 variability, chlorine activation, sulfuric-acid cloud formation, and the still-unassigned near-UV absorber, yet several sulfur–chlorine intermediates in this network remain molecularly undefined. ClSO4 is one of them: it has been invoked as a chlorine-assisted route toward SO3 and H2SO4, but its structure and spectroscopy have not been established. We report a focused ab initio characterization of neutral doublet ClSO4 centered on explicit validation of its electronic structure. Multireference calculations with two independent active spaces locate the same O-bound chlorine sulfate radical and show that the relevant structure is not strongly multiconfigurational. An independent second-order perturbation-theory optimization recovers the same bond-localized topology, but the coupled-cluster minus second-order perturbation correction substantially refines the radical-bearing S–O distance, showing that second-order perturbation theory alone is not sufficient for final structural parameters. Final structural parameters are therefore obtained from a composite geometry, including explicit-correlation to account for basis-set extension, post-second-order correlation, and core–valence increments, whereas the vibrational analysis uses a second-order perturbation-theory force field and second-order vibrational perturbation treatment. The resulting vibrational spectrum contains a compact set of intense infrared markers, and the electronic absorption spectrum extends into the near-UV/visible region. These results establish ClSO4 as a chemically plausible and spectroscopically accessible intermediate in Venus sulfur–chlorine chemistry.
Enhancing the security of coherent one-way quantum key distribution using CHSH correlations
Abstract The coherent one-way (COW) protocol is a quantum key distribution scheme that has attracted significant attention, leading to the development and commercialization of practical implementations. Despite this progress, the security of the COW protocol has remained a fundamental challenge since its introduction. Numerous studies have investigated its security, and several security proofs have been proposed over the years. More recently, a number of works have questioned the security of this protocol. In particular, one of the latest studies introduced an attack that severely limits the security of COW-QKD and reported a maximum secure distance of less than $$20\,\textrm{km}$$ . In this work, we introduce minimal alteration to the COW protocol that can enhance its security. Specifically, instead of monitoring the coherence between successive pulses, we propose to monitor quantum correlations through the violation of Bell inequalities. This approach enables the detection of a broader class of potential attacks. Our simulation results indicate that, by employing this method, the maximum secure distance of the protocol can be extended to approximately $$259\,\textrm{km}$$ .
Ion-specific anomalous water diffusion in aqueous electrolytes: A machine-learned many-body force field study with MACE
The dynamics of water in electrolyte solutions exhibits a striking, ion-specific anomaly: the diffusion coefficient of water is enhanced relative to the neat liquid in chaotropic CsI solutions, yet suppressed in kosmotropic NaCl solutions. This phenomenon, long challenging for classical force-field-based molecular dynamics, is studied here using classical molecular dynamics simulations with a many-body machine-learned force field trained within the MACE equivariant graph neural network framework. The force field is trained on energies, forces, and stresses computed at the density functional theory level with the revPBE-D3 exchange–correlation functional, which provides a reliable balance between accuracy and computational efficiency for aqueous systems. Simulations of NaCl and CsI aqueous solutions under ambient conditions over a concentration range of 0.89–3.56 mol/kg reproduce the experimentally observed anomalous diffusion and yield a quantitative improvement over previous results obtained with the DeePMD framework, which is trained on the same theory, particularly for NaCl solutions. This improvement is traced to a stronger Na+–water interaction in the first hydration shell and the non-negligible retarding contribution of the second hydration shell of Na+. For CsI solutions, the water acceleration is shown to be primarily driven by the anion I−, whose diffuse and weakly structured hydration shell facilitates rapid water exchange with the bulk. These results are rationalized through a shell-decomposition analysis of time-dependent water diffusivities and ion–oxygen potentials of mean force, providing a coherent microscopic picture of the acceleration–retardation mechanism in the studied aqueous electrolytes.
A complete blood count–based prediction model for ferritin-defined iron deficiency
Electrohydrodynamic lubrication theory for an immersed cylinder moving near wall
The free motion of charged colloids within ionic solutions and in the vicinity of charged boundaries is a phenomenon that occurs in various natural, biological, and industrial settings. Here, we develop an electrohydrodynamic lubrication theoretical framework in order to characterize such a motion in the case of an infinite rigid cylinder near a rigid wall. Combining hydrodynamic lubrication theory, Debye–Hückel electrostatics, and Nernst–Planck electrokinetics, we derive the three coupled equations of motion for the normal, longitudinal, and rotational degrees of freedom of the cylinder, which are then investigated numerically and through asymptotic analysis. Our results reveal complex behaviors, beyond existing asymptotic electroviscous-lift expressions, and extend the classical Faxen–Brenner-like mobility matrix when surface charges and dissolved ions are incorporated.
A hybrid structural and artificial intelligence approach for cybersecurity situational awareness among high school students
Direct ambient synthesis of cerium-sensitized Cs3TbCl6 microcrystals with near-unity photoluminescence quantum yield and robust stability for white lighting
Recently, lead-free zero-dimensional Cs3TbCl6 (CTC) microcrystals have shown great potential for applications in light-emitting diodes. However, two major limitations of CTC are their low absorption coefficient and harsh preparation. In this study, Ce3+ with 4f–5d orbital coupling was used to dope CTC, enabling the excitation band to shift from UV-B to UV-A and elevating the photoluminescence quantum yield from 33.52% to 96.43%. In addition, cerium-sensitized CTC microcrystals (MCs) with different dopant ratios were obtained to study the energy transfer process from Ce3+ to Tb3+, which were prepared via a simple monosolvent ethanol-assisted recrystallization method at room temperature. Finally, we used cerium-sensitized CTC MCs with excellent stability to fabricate the white light-emitting diodes. This work not only offers a deep understanding of competitive energy transfer in zero-dimensional lanthanide-based metal halides, but also presents a direct ambient synthesis strategy of highly emissive and robustly stable phosphor for white light illumination.
A hybrid generative and transformer-based framework for anomaly detection in industrial sensor time-series for predictive maintenance
Efficient analytic continuation approach to Bethe–Salpeter excitation spectra in selected energy windows
We explore the merits of building the Bethe–Salpeter absorption spectrum in a specific energy range using analytic continuation techniques. Specifically, we calculate iteratively a few ᾱ̄(zk) polarizability tensors for a coarse set of (zk) frequencies in the complex-plane. These data allow the construction of a continued-fraction representation for ᾱ̄(z) that is used to calculate the absorption spectrum close to the real energy axis in the desired energy range. The number and location of these sampling complex frequencies are discussed. The importance of building a continued-fraction representation of the full polarizability tensor with matrix-valued coefficients is emphasized. We show how to extract the poles of the continued fraction as a tool for analyzing the resulting spectra. We study as examples the valence excitations of a paradigmatic dipeptide, the C60 fullerene and its [6,6]-phenyl-C61-butyric acid methyl ester derivative, together with the description of the surface plasmon resonance of the Ag20 silver cluster. Furthermore, the high-energy C60 X-ray absorption spectrum is explored.
Integrated magnetic and hydrochemical forensic assessment of dumpsite-induced soil and groundwater contamination and the possible implications for public health
Abstract Uncontrolled waste disposal in developing nations poses a significant risk to shallow water resources and nearby communities. This study integrated hydrochemical analysis with ground magnetic surveying to assess dumpsite-related contamination around ten dumpsites within the Kaduna Metropolis. Twenty-five water samples, comprising 15 hand-dug wells and 10 rivers/streams within 200 m of the dumpsites, were analyzed for pH, EC, TDS, total hardness, BOD 5 , COD, Fe, and Pb using standard APHA procedures with routine QA/QC checks. A ground magnetic survey was conducted at one representative central dumpsite to map shallow waste heterogeneity. Hydrochemical results showed degraded water quality, with EC (709–2612 µS/cm), TDS (510–1612 mg/L), BOD 5 (371–798 mg/L), COD (697–1477 mg/L), Pb (0.16–1.92 mg/L), and Fe (0.33–2.42 mg/L) commonly exceeding drinking-water guideline values, and surface waters generally more impaired than hand-dug wells. The BOD 5 /COD relationship indicates mixed organic contamination with an appreciable biodegradable fraction rather than “water content.” Magnetic data revealed multiple shallow anomalies (about 0–5 m) related to ferromagnetic debris and heterogeneous fill, but did not by themselves establish leachate chemistry. Overall, dumpsite impacts are best characterized by combining magnetic, hydrochemical, and hydrogeological evidence. Improved waste containment, routine monitoring, and targeted remediation are urgently needed.
Observation of Penning electron detachment from H− induced by metastable H*/Ng* atoms (Ng = He, Ne, Ar, Kr, Xe)
In Penning detachment, the excess electron of an anion is detached during the anion’s collision with an electronically excited neutral species (A− + N* → A + N + e−). Penning detachment of H− has special relevance to the dynamics of stellar atmospheres and to possible technological uses. Penning detachment by excited (metastable) hydrogen and helium atoms may be the most important H− loss-step in the solar atmosphere. Here, the Penning detachment of H−/D− by collisions with H*(22S) and He*(23S/21S) excited atoms, i.e., H−/D− + H*/He* → H/D + H/He + e−, was observed for the first time via direct H−/D− anion depletion experiments. Penning detachment of H− by metastable noble gases (Ng* = He*, Ne*, Ar*, Kr*, Xe*) was observed as well, with potential applications in tokamak fusion devices being proposed.