bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of liquid–vapor interfaces: Perspectives from liquid state theory, large-scale simulations, and potential grazing-incidence x-ray diffraction
Authors: Höfling F. , Dietrich S.
Published: March 2024

Grazing-incidence x-ray diffraction (GIXRD) is a scattering technique that allows one to characterize the structure of fluid interfaces down to the molecular scale, including the measurement of surface tension and interface roughness. However, the corresponding standard data analysis at nonzero wave numbers has been criticized as to be inconclusive because the scattering intensity is polluted by the unavoidable scattering from the bulk. Here, we overcome this ambiguity by proposing a physically consistent model of the bulk contribution based on a minimal set of assumptions of experimental relevance. To this end, we derive an explicit integral expression for the background scattering, which can be determined numerically from the static structure factors of the coexisting bulk phases as independent input. Concerning the interpretation of GIXRD data inferred from computer simulations, we extend the model to account also for the finite sizes of the bulk phases, which are unavoidable in simulations. The corresponding leading-order correction beyond the dominant contribution to the scattered intensity is revealed by asymptotic analysis, which is characterized by the competition between the linear system size and the x-ray penetration depth in the case of simulations. Specifically, we have calculated the expected GIXRD intensity for scattering at the planar liquid–vapor interface of Lennard-Jones fluids with truncated pair interactions via extensive, high-precision computer simulations. The reported data cover interfacial and bulk properties of fluid states along the whole liquid–vapor coexistence line. A sensitivity analysis shows that our findings are robust with respect to the detailed definition of the mean interface position. We conclude that previous claims of an enhanced surface tension at mesoscopic scales are amenable to unambiguous tests via scattering experiments.
High-definition direct-print of metallic microdots with optical vortex induced forward transfer
Authors: Wei Rong , Kawaguchi Haruki , Sato Kaito , Kai Sayaka , Yamane Keisaku , Morita Ryuji , Yuyama Ken-ichi , Kawano Satoyuki , Miyamoto Katsuhiko , Aoki Nobuyuki , Omatsu Takashige
Published: March 2024

We demonstrate high-definition, direct-printing of micron-scale metallic dots, comprised of close-packed gold nanoparticles, by utilizing the optical vortex laser-induced forward transfer technique. We observe that the spin angular momentum of the optical vortex, associated with circular polarization, assists in the close-packing of the gold nanoparticles within the printed dots. The printed dots exhibit excellent electrical conductivity without any additional sintering processes. This technique of applying optical vortex laser-induced forward transfer to metallic dots is an innovative approach to metal printing, which does not require additional sintering. It also serves to highlight new insights into light–matter interactions.
Enhanced sensitivity of MoS2:Er-based flexible near-infrared photodetectors via tellurium-induced interfacial charge transfer
Authors: Wang Lei , Song Enhai , Ji Xiaohong , Zhang Qinyuan
Published: March 2024

The persistent photoconductive behavior caused by traps in the active materials usually weakens the sensitivity and stability of photodetectors. Herein, tellurium (Te) microwire and polyvinyl alcohol (PVA) composites were developed as functional flexible substrates to improve the near-infrared (NIR) photoresponse performance of MoS2:Er-based devices with the metal–semiconductor–metal structure. The flexible photodetector exhibits a rise/fall time of ∼2.9–3.1 ms, a responsivity of ∼0.28 mA W−1, and a detectivity of ∼1.41 × 1010 Jones under 808 nm irradiation. The enhanced mechanism can be attributed to the charge transfer between Te microwires and MoS2:Er films, which suppresses the dark current of the device and optimizes the generation process of electron–hole pairs under light illumination. Meanwhile, the flexibility of the device allows it to be employed in human heart rate monitoring. This work offers a simple and essential strategy for constructing integrated flexible NIR photodetectors with high performance.
Real-time and calibration-free generalized terahertz time-domain spectroscopic ellipsometry
Authors: Chen Hao , Wang Kaijie , Chen Xuequan , Fang Guangyou
Published: March 2024

Spectroscopic ellipsometry is a high-precision and powerful optical characterization technique, which can be categorized into two fundamental types of standard and generalized ellipsometry. The latter can obtain the complete Jones matrix to investigate various anisotropic samples. However, terahertz generalized ellipsometry has traditionally relied on frequency-domain instrumentation, which is limited in bandwidth, complicated in polarization manipulation, and slow in operation. In this study, we propose a highly accurate and efficient terahertz time-domain generalized ellipsometer based on a polarization beam coupler-splitter configuration. It measures four independent complex spectra in real-time without mechanical movement, providing ultrahigh data throughput. Each polarizer-antenna unit constructively superimposes their filtering effect, resulting in a 45–65 dB extinction ratio that approaches the system dynamic range. The superb illumination and detection linearity provides an outstanding polarization accuracy and eliminates the need for complicated calibration. Reflection characterization of the magneto-optical properties of an InAs wafer demonstrates the generalized ability to simultaneously obtain multiple dielectric functions. Transmission ellipsometric imaging of liquid crystals subjected to an inhomogeneous electric field further highlights the excellent efficiency. The proposed technique significantly expands the capabilities of terahertz spectroscopy, paving ways to anisotropic materials, in situ monitoring, and polarization-sensitive devices.
On the transition from single- to multi-humped internal solitary waves
Authors: La Forgia G. , Sciortino G. , Lombardi V. , Prestininzi P.
Published: March 2024

We provide numerical evidence of the transition from rank-ordered trains of internal solitary waves (ISWs) to multi-humped packets. We ascribe such peculiar and unexplored dynamics to the emergence of a long-range influence among waves, mediated by the hydrodynamic conditions developing in the wake of each ISW and promoting acceleration of the trailing waves. Both the train during the transition and its final multi-humped configuration share hydrodynamic features which are consistent with the recently proposed theory of ISWs propagating through moving stratified environments.
Comparison of flow characteristics of plane jet impingement on a solid plate and on a sand bed
Authors: Mao Jieyun , Si Jin-Hua , Li Guidong , Wang Xikun
Published: March 2024

As compared to the well-researched case of a plane jet impinging on a solid plate, relatively rare attention was paid to the impingent on an erodible sand bed, which induces continuous bed transformations and interactively affects the jet development. The present study measured the flow of an impinging plane jet on a solid plate and on an erodible sand bed, respectively, by using particle image velocimetry technology, and then comparatively investigated the flow structure, main jet development and downstream wall jet development for the two cases. The results revealed that the jet impingement on the sand bed has a longer free jet region than that on the solid plate due to enlarged separation distance induced by localized scouring. The width of the plane jet impinging on the sand bed is larger than that on the plate by as high as five times the nozzle width, due to intensified interactions with the complex vortical structures in the concave scour hole. The impinging angle even decreases to negative values near the sand bed due to upward deflection of flow induced by bedform transformation. For both cases, however, the normalized streamwise mean velocity profiles exhibit universal self-similarity at different zones of jet development: specifically, the main jet and the wall jet satisfy exactly the same exponential function and the power law function, respectively.
Phase separation in the presence of fractal aggregates
Authors: Ghosh Supriyo , Douglas Jack F.
Published: March 2024

Liquid–liquid phase separation in diverse manufacturing and biological contexts often occurs in the presence of aggregated particles or complex-shaped structures that do not actively participate in the phase separation process, but these “background” structures can serve to direct the macroscale phase separation morphology by their local symmetry-breaking presence. We perform Cahn–Hilliard phase-field simulations in two dimensions to investigate the morphological evolution, wetting, and domain growth phenomena during the phase separation of a binary mixture in contact with model fractal aggregates. Our simulations reveal that phase separation initially accelerates around the fractal due to the driving force of wetting, leading to the formation of the target composition patterns about the fractals, as previously observed for circular particles. After the formation of a wetting layer on the fractal, however, we observe a dramatic slowing-down in the kinetics of phase separation, and the characteristic domain size eventually “pins” to a finite value or approaches an asymptotic scaling regime as an ordinary phase if the phase separation loses memory of the aggregates when the scale of phase separation becomes much larger than the aggregate. Furthermore, we perform simulations to examine the effects of compositional interference between fractals with a view to elucidating interesting novel morphological features in the phase-separating mixture. Our findings should be helpful in understanding the qualitative aspects of the phase separation processes in mixtures containing particle aggregates relevant for coating, catalyst, adhesive, and electronic applications as well as in diverse biological contexts, where phase separation occurs in the presence of irregular heterogeneities.
Broadband transmissive polarization rotator by gradiently twisted
α
-MoO3
Authors: Hou Songyan , Hu Hao , Liu Zhihong , Xing Weichuan , Zhang Jincheng
Published: March 2024

Polarization engineering has been proven to enhance the capabilities of light manipulation and thus facilitate the development of integrated photonic devices. In this study, we introduce a polarization rotator based on a gradiently twisted α-MoO3 thin film, which works in the mid-infrared range and functions in a transmission mode. To be specific, the proposed device is constructed by gradiently twisted α-MoO3 multilayers with a subwavelength thickness of only 5 μm, namely, one-third of the working wavelength. Our analytical calculation demonstrates the efficacy of this subwavelength thin film rotator in converting a linearly polarized wave into its orthogonal counterpart, thanks to its chiral nature. The twisted α-MoO3 multilayers exhibit the capability to significantly manipulate dispersion characteristics while maintaining low optical losses, thereby enabling a wide bandwidth exceeding 2.5 THz with a polarization ratio surpassing 17 dB. Moreover, the operational frequency can be adjusted across a 3.4 THz range by altering the incident angle of the incident waves. This adaptable design, characterized by its polarization versatility, can be customized to suit practical applications within wireless communication, radar systems, optical switching, and imaging technologies.
Accumulation and removal of Si impurities on β-Ga2O3 arising from ambient air exposure
Authors: McCandless J. P. , Gorsak C. A. , Protasenko V. , Schlom D. G. , Thompson Michael O. , Xing H. G. , Jena D. , Nair H. P.
Published: March 2024

Here, we report that a source of Si impurities commonly observed on (010) β-Ga2O3 is from exposure of the surface to air. Moreover, we find that a 15 min hydrofluoric acid (HF) (49%) treatment reduces the Si density by approximately 1 order of magnitude on (010) β-Ga2O3 surfaces. This reduction in Si is critical for the elimination of the often observed parasitic conducting channel, which negatively affects transport properties and lateral transistor performance. After the HF treatment, the sample must be immediately put under vacuum, for the Si fully returns within 10 min of additional air exposure. Finally, we demonstrate that performing a 30 min HF (49%) treatment on the substrate before growth has no deleterious effect on the structure or on the epitaxy surface after subsequent Ga2O3 growth.
Excitation energy transfer and vibronic relaxation through light-harvesting dendrimer building blocks: A nonadiabatic perspective
Authors: Galiana Joachim , Lasorne Benjamin
Published: March 2024

The light-harvesting excitonic properties of poly(phenylene ethynylene) (PPE) extended dendrimers (tree-like π-conjugated macromolecules) involve a directional cascade of local excitation energy transfer (EET) processes occurring from the “leaves” (shortest branches) to the “trunk” (longest branch), which can be viewed from a vibronic perspective as a sequence of internal conversions occurring among a connected graph of nonadiabatically coupled locally excited electronic states via conical intersections. The smallest PPE building block that is able to exhibit EET, the asymmetrically meta-substituted PPE oligomer with one acetylenic bond on one side and two parallel ones on the other side (hence, 2-ring and 3-ring para-substituted pseudo-fragments), is a prototype and the focus of the present work. From linear-response time-dependent density functional theory electronic-structure calculations of the molecule as regards its first two nonadiabatically coupled, optically active, singlet excited states, we built a (1 + 2)-state-8-dimensional vibronic-coupling Hamiltonian model for running subsequent multiconfiguration time-dependent Hartree wavepacket relaxations and propagations, yielding both steady-state absorption and emission spectra as well as real-time dynamics. The EET process from the shortest branch to the longest one occurs quite efficiently (about 80% quantum yield) within the first 25 fs after light excitation and is mediated vibrationally through acetylenic and quinoidal bond-stretching modes together with a particular role given to the central-ring anti-quinoidal rock-bending mode. Electronic and vibrational energy relaxations, together with redistributions of quantum populations and coherences, are interpreted herein through the lens of a nonadiabatic perspective, showing some interesting segregation among the foremost photoactive degrees of freedom as regards spectroscopy and reactivity.
Assessing nozzle flow dynamics in fused filament fabrication through the parametric map α−λ
Authors: Schuller Tomás , Fanzio Paola , Galindo-Rosales Francisco J.
Published: March 2024

Polymer rheology profoundly influences the intricate dynamics of material extrusion in fused filament fabrication (FFF). This numerical study, which uses the Giesekus model fed with a full rheometric experimental dataset, meticulously examines the molten flow patterns inside the printing nozzle in FFF. Our findings reveal new insight into the interplay between elastic stresses and complex flow patterns, highlighting their substantial role in forming upstream vortices. The parametric map α–λ from the Giesekus model allowed us to sort the materials and connect the polymer rheology with the FFF nozzle flow dynamics. The identification of elastic instabilities, the characterization of flow types, and the correlation between fluid rheology and pressure drop variations mark significant advancements in understanding FFF processes. These insights pave the way for tailored nozzle designs, promising enhanced efficiency and reliability in FFF-based additive manufacturing.
Rapid coating of polyamide, polyurea, and polythiourea on metal–organic framework surfaces
Authors: Huang Yunmei , Qi Anheng , Li Siqi , Tang Lu , Zhao Yingbo , Li Tao
Published: March 2024

Well-defined metal–organic framework (MOF)@polymer core–shell composite particles with polyamide, polyurea, and polythiourea as the shell layer have been constructed for the first time using non-solvent-induced surface-aimed polymerization. This surface polymerization method utilizes non-solvent-induced phase separation to concentrate and direct monomers onto MOF particle surfaces, thus completing the coating process in less than 5 min. The generalizability of this method has been demonstrated with different MOFs. Coating MOF particles with any of the three polymers can effectively improve the stability of the MOF in harsh chemical environments. When used for heavy metal removal, polythiourea-coated composite particles (MOF@HDA-PDTC) exhibited a drastically improved Hg(II) removal rate and full utilization of the thione groups for Hg(II) binding compared to their neat polymer counterparts. This highlights the unique benefit of this core–shell architecture for the optimization of diffusion.
A linear cross-coupled gate-driven quasi-floating bulk low-power wide input range transconductor
Authors: Sharma Kulbhushan , Sachdeva Ashish
Published: March 2024

High linearity for a wider input voltage range and low-power operation of the operational transconductance amplifier (OTA) are indispensable parameters for health care applications, which require high quality and accurate signal conditioning. However, achieving low-power operation along with high linearity at low supply voltages is challenging for OTA using conventional low-power and linearization techniques. This paper proposes an OTA based on a cross-coupled gate-driven quasi-floating bulk (CGDQFB) MOSFET and source-degenerated linearization techniques, which works at a supply of ±0.5 V. The post-layout simulations of the proposed OTA are performed in the 180 nm standard CMOS process, which shows a transconductance of 0.321 μS, an output impedance of 331 MΩ, an input impedance of 897 GΩ, a DC gain of 40.54 dB, a gain-bandwidth of 0.145 MHz, a total harmonic distortion (THD) of 51.09 dB for an input voltage range of 626.7 mV at a frequency of 100.39 Hz, and a power consumption of 0.45 μW. The proposed OTA shows an input common mode range of −0.34 to 0.4 V, an output voltage swing of −0.34 to 0.34 V, a common mode rejection ratio of 91.08 dB, and a consumption area of 23 965.92 µm2. Furthermore, with 200 Monte Carlo iterations, the proposed OTA shows variability for gain and THD of 0.003 and 0.036, respectively. The proposed CGDQFB OTA is a suitable contender for conditioning bio-signals used in health care applications.
High-energy electron injection in top-gated niobium microbridges for enhanced power efficiency and localized control
Authors: Du Hongmei , Xu Zuyu , Zhang Ping , Li Dingding , Wei Zihan , Wang Zixi , Hou Shoucheng , Chen Benwen , Liu Tao , Liu Ruxin , Lyu Yang-Yang , Sun Hancong , Wang Yong-Lei , Wang Huabing , Wu Peiheng
Published: March 2024

This study explores gate-controlled superconductivity in metallic superconductors by employing a top-gate architecture with a 15 nm monocrystalline h-BN as a gate dielectric. The transport properties under gate voltage can be elucidated by injecting high-energy electrons, following the Fowler–Nordheim electron field emission model. In contrast to conventional resistive Joule heating, high-energy electron injection with top-gating exhibits excellent power efficiency in suppressing superconductivity. A nearby superconducting bridge, which serves as a thermometer, indicates that our top-gate device can achieve good local control, well limited within a distance of 0.6 μm due to the very low top-gating power. These findings are essential for advancing efficient and highly integrated tunable superconducting electronic devices.
Direct numerical simulation of channel flow with real surface roughness using a ghost cell immersed boundary method
Authors: Zeng Xian , Zhang Yang , Cui Jiahuan , Xiao Zuoli , Luo Jiaqi
Published: March 2024

This paper investigates the impact of real surface roughness on channel flow using direct numerical simulation assisted by a ghost cell immersed boundary method (DNS-GCIBM). The principles and implementations of DNS-GCIBM are first introduced. Two test cases, including the two-dimensional flow around a cylinder and the three-dimensional flow in a sinusoidal roughness channel are employed to demonstrate the practicability and accuracy of the proposed approach, especially in numerical studies on the rough wall-bounded flow. Using DNS-GCIBM, channel flows under conditions of Ma = 0.3 and Reτ≈300, with both the real-world and regular roughness surfaces are studied. The results are statistically analyzed using the triple decomposition technique. The outer layer similarity in the streamwise mean velocity and Reynolds stress profiles indicate that the impact of roughness on the boundary layer primarily localizes within roughness sub-layer. In the streamwise mean velocity profile, both regular and real-world roughness surfaces induce obvious increase to the roughness function ΔU+ as roughness height Ra increases, while discrepancy of ΔU+ between the two types of roughness can be found. Furthermore, turbulence statistics are sensitive to the variations of Ra. As Ra increases, it becomes challenging to organize coherent structures near the wall, resulting in the reduction of streamwise Reynolds stress intensity. In addition, although the skin friction coefficient and ΔU+ are almost the same, the real-world roughness and the corresponding equivalent regular roughness manifest different flow structures near the wall. The real-world roughness contributes greater spatial inhomogeneity but lower turbulence intensity.
Numerical study of wind characteristics at a long-span bridge site in mountain valley
Authors: Jing Hongmiao , Li Weikang , Su Yi , Zhao Wanru , Zhang Jitao , Qiao Mingzhe , Liu Qingkuan
Published: March 2024

Wind loads play an important role in the design and construction of long-span bridges, especially for that built in mountain valley, and wind characteristics in mountain terrain are still unclear. To further understand the wind characteristics at a bridge site in a mountain valley, large eddy simulations were employed to comprehensively study the wind characteristics at the bridge site in an L-shaped canyon. Different wind directions consisting of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° were considered, and the wind characteristics on the main girder and towers, as well as the flow field, were comprehensively investigated. The results indicate that the mean and fluctuating wind characteristics are significantly different from those specified in the relevant specifications, and it is inappropriate to apply the specifications directly to mountainous terrain. When wind flows along a channel, it leads to a large wind speed amplification factor, strong non-Gaussianity, and large kurtosis and skewness. The steeper the slope of the mountain, the stronger the non-Gaussianity of the fluctuating wind. The coherence function remains nearly unchanged when the distance between the two points is constant, regardless of the location. The wind characteristics at the main girder and towers are so different that they should be considered separately and taken into account in engineering practice. This study provides a reference for the wind-resistant design of bridges and structures built on mountainous terrains.
Enhanced terahertz high-harmonic generation from high-Q quasi-bound states in the continuum empowered by permittivity-broken metasurface
Authors: Sun Guangcheng , Wang Yue , Cui Zijian , Xie Rongbo , Zhao Xiaoguang
Published: March 2024

The extraordinary emergence of all-dielectric resonant meta-photonics underpinned by high refractive index and low optical loss materials promises a standout platform for unprecedented manipulation and subwavelength control of light. Recent significant breakthroughs in meta-photonics have to do with the exploration of the non-radiative eigenmodes that lie inside the light cone, called the bound states in the continuum (BICs), which have demonstrated considerable potential to achieve high quality (Q) factors but require ultra-small structure asymmetry, complicating fabrication and hindering precise control of Q factors. Here, we propose a scheme to excite quasi-BICs by breaking symmetry in the permittivity of the comprising meta-atoms where small permittivity perturbation renders the same effect in the conventional geometrically asymmetric design. Empowered by the insignificant permittivity perturbation introduced from chemical doping and carrier injection, arbitrarily small permittivity asymmetry, that is, infinitely high-Q factor, can be precisely and dynamically tailored. As an example of application, we numerically show the THz range, exceptionally high conversion efficiency for both third-harmonic and fifth-harmonic generation from the permittivity-broken metasurface (MS) benefiting from the extreme field confinement at high-Q quasi-BICs resonance. Our results present a feasible and efficient strategy to mitigate the shortcomings of previous photonic platform and shall shed light on the advances of nonlinear all-dielectric THz-MS.
Eigenvalue approach for investigating thermal and mechanical responses on living tissues during laser irradiation with experimental verification
Authors: Hobiny A. , Abbas I.
Published: March 2024

This study provides analytical solutions for the non-Fourier theory, which accounts for bioheat transfer in biological tissue when exposed to laser irradiation. To perform thermal treatment procedures effectively, a thorough comprehension of both the heat transmission mechanism and the subsequent thermal and mechanical interaction within the patient's human tissue is essential. The assessment of thermal injuries to the tissue involves determining the extent of denatured proteins using the Arrhenius formulation. The bio-thermoelastic model presented employs Laplace transforms and analytical techniques to establish governing formulations. Subsequently, an eigenvalues scheme is utilized to derive solutions to these equations. Graphical representations of the results for temperature, displacements, and stress are provided. The analytical solution's accuracy is verified through a comparison with numerical and experimental data. Results indicate that, when both have zero thermal lag times, the generalized non-Fourier model aligns with the Pennes bioheat transfer model. Furthermore, the effectiveness of the mathematical model in evaluating bioheat transfer in biological tissues is validated by comparing it with established experimental data.
Situating the phosphonated calixarene–cytochrome C association by molecular dynamics simulations
Authors: Bartocci Alessio , Dumont Elise
Published: March 2024

Protein–calixarenes binding plays an increasingly central role in many applications, spanning from molecular recognition to drug delivery strategies and protein inhibition. These ligands obey a specific bio-supramolecular chemistry, which can be revealed by computational approaches, such as molecular dynamics simulations. In this paper, we rely on all-atom, explicit-solvent molecular dynamics simulations to capture the electrostatically driven association of a phosphonated calix-[4]-arene with cytochome-C, which critically relies on surface-exposed paired lysines. Beyond two binding sites identified in direct agreement with the x-ray structure, the association has a larger structural impact on the protein dynamics. Then, our simulations allow a direct comparison to analogous calixarenes, namely, sulfonato, similarly reported as “molecular glue.” Our work can contribute to a robust in silico predictive tool to assess binding sites for any given protein of interest for crystallization, with the specificity of a macromolecular cage whose endo/exo orientation plays a role in the binding.
Zero shear viscosity of two polyatomic glass-forming liquids calculated by Vogel–Fulcher law and schematic mode-coupling theory
Authors: Wong Chi Pui Jeremy , Choi Phillip
Published: March 2024

A theoretical method based on the simple Vogel–Fulcher law for estimating the zero shear viscosity of two glass-forming liquids, 1,3-bis(1-nathtyl)-5–(2-naphthyl) benzene and polystyrene, over a range of temperatures from that close to their glass transition temperatures to high temperatures was reported. One parameter of this model, i.e., the critical number density, at which particles are trapped in a cage that only segmental vibration is possible was identified using the intermolecular radial distribution function derived from the Percus–Yevick integral equation and a simplified schematic mode-coupling theory.
Pseudo-marginal approximation to the free energy in a micro–macro Markov chain Monte Carlo method
Authors: Vandecasteele Hannes , Samaey Giovanni
Published: March 2024

We introduce a generalized micro–macro Markov chain Monte Carlo (mM-MCMC) method with pseudo-marginal approximation to the free energy that is able to accelerate sampling of the microscopic Gibbs distributions when there is a time-scale separation between the macroscopic dynamics of a reaction coordinate and the remaining microscopic degrees of freedom. The mM-MCMC method attains this efficiency by iterating four steps: (i) propose a new value of the reaction coordinate, (ii) accept or reject the macroscopic sample, (iii) run a biased simulation that creates a microscopic molecular instance that lies close to the newly sampled macroscopic reaction coordinate value, and (iv) microscopic accept/reject step for the new microscopic sample. In the present paper, we eliminate the main computational bottleneck of earlier versions of this method: the necessity to have an accurate approximation of free energy. We show that the introduction of a pseudo-marginal approximation significantly reduces the computational cost of the microscopic accept/reject step while still providing unbiased samples. We illustrate the method’s behavior on several molecular systems with low-dimensional reaction coordinates.
The stability analysis based on viscous theory of Faraday waves in Hele–Shaw cells
Authors: Li Xingsheng , Li Jing
Published: March 2024

The linear instability of Faraday waves in Hele–Shaw cells is investigated with consideration of the viscosity of fluids after gap-averaging the governing equations due to the damping from two lateral walls and the dynamic behavior of contact angle. A new hydrodynamic model is thus derived and solved semi-analytically. The contribution of viscosity to critical acceleration amplitude is slight compared to other factors associated with dissipation, and the potential flow theory is sufficient to describe onset based on the present study, but the rotational component of velocity can change the timing of onset largely, which paradoxically comes from the viscosity. The model degenerates into a novel damped Mathieu equation if the viscosity is dropped with two damping terms referring to the gap-averaged damping and dissipation from dynamic contact angle, respectively. The former increases when the gap size decreases, and the latter grows as frequency rises. When it comes to the dispersion relation of Faraday waves, an unusual detuning emerges due to the imaginary part of the gap-averaged damping.
Compressed Hermite–Gaussian differential single-pixel imaging
Authors: Huang Guancheng , Shuai Yong , Ji Yu , Zhou Xuyang , Li Qi , Liu Wei , Gao Bin , Liu Shutian , Liu Zhengjun , Li Yutong
Published: March 2024

Traditional single-pixel imaging (SPI) encounters challenges such as high sampling redundancy and poor imaging quality, constraining its widespread application. Despite a range of orthogonal modulation modes have been employed in structured illumination to enhance imaging performance, some encoding issues still persist in information sampling, impeding the further progression of SPI. We propose an SPI method based on orthogonal Hermite–Gaussian (HG) moments, achieving improved imaging reconstruction through differential modulation of HG basis patterns and linear weighting of acquired intensity. Both simulations and experiments confirm superior imaging quality and computation efficiency of proposed Hermite–Gaussian single-pixel imaging (HG-SI), especially at low-measurement levels. Moreover, we incorporate compressed sensing algorithms within the framework of HG-SI, integrating moments-based sampling strategies to optimize imaging capability under sparse measurements. Our research underscores the effectiveness of HG modulation in SPI reconstruction, enabling high-quality outcomes via compressed sampling. This advancement propels the investigation of optical field modulation modes within SPI and holds promise in offering a universal solution for weak-intensity and non-visible light microscopy.
Development of high-amylose maize (Zea mays L.) genotypes adapted to Indian conditions through molecular breeding
Authors: Arora Arushi , Bhamare Deepak , Das Abhijit Kumar , Dixit Shubhank , Venadan Sreya , K. R. Yathish , Kumar Ramesh , Paul Dharam , Sekhar J. C. , Neelam Sunil , Nandi Sudip , Kamboj M. C. , Rakshit Sujay
Published: March 2024

Context Amylose is a type of resistant starch with numerous health benefits and industrial applications. Starch from maize (Zea mays L.) usually has an amylose content of ~25%. Aims The aim was to develop high-amylose maize genotypes suitable for human consumption and adapted to Indian conditions. Methods Marker-assisted backcross breeding was used to transfer the mutant ae1 allele from a high-amylose donor from the USA into the three parents (HKI 1344, HKI 1378, HKI 1348-6-2) of two high-yielding white maize hybrids (HM5 and HM12) grown in India. Key results In converted lines, amylose content was 40.40–58.10% of total kernel starch, compared with 22.25–26.39% in parents. The percentage increase in amylose content was 63.70–153.03%. There was a significant amount of background recovery in each backcross generation: 66.80–79% in BC1F1, 72.85–88.60% in BC2F1, and 84.45–93.70% in BC2F2. Overall, the total kernel starch content was reduced (by ~22%) in the ae1-introgressed families. Conclusions The converted lines developed in the study are enriched with kernel amylose while showing significant background recovery. Implications The high-amylose lines developed may be highly beneficial for diabetic patients and in the bioplastics industry, and should be suitable for growing under Indian conditions.
The future of equine semen analysis
Authors: Peña Fernando J. , Martín-Cano Francisco Eduardo , Becerro-Rey Laura , Ortega-Ferrusola Cristina , Gaitskell-Phillips Gemma , da Silva-Álvarez Eva , Gil María Cruz
Published: March 2024

We are currently experiencing a period of rapid advancement in various areas of science and technology. The integration of high throughput ‘omics’ techniques with advanced biostatistics, and the help of artificial intelligence, is significantly impacting our understanding of sperm biology. These advances will have an appreciable impact on the practice of reproductive medicine in horses. This article provides a brief overview of recent advances in the field of spermatology and how they are changing assessment of sperm quality. This article is written from the authors’ perspective, using the stallion as a model. We aim to portray a brief overview of the changes occurring in the assessment of sperm motility and kinematics, advances in flow cytometry, implementation of ‘omics’ technologies, and the use of artificial intelligence/self-learning in data analysis. We also briefly discuss how some of the advances can be readily available to the practitioner, through the implementation of ‘on-farm’ devices and telemedicine.
Taxonomic study of Senna section Chamaefistula series Bacillares (Fabaceae) in the Atlantic Forest north of the São Francisco River, Brazil, and nomenclatural updates
Authors: Souto Flávio Sousa , de Queiroz Rubens Teixeira , Agra Maria de Fátima
Published: March 2024

Senna section Chamaefistula series Bacillares (Benth.) H.S.Irwin & Barneby comprises ~50 Neotropical legume species occurring in both tropical and subtropical areas. Approximately 25 of those species occur in Brazil, with nine being endemic. This work provides a taxonomic study of Senna section Chamaefistula series Bacillares in the Atlantic Forest north of the São Francisco River in north-eastern Brazil, which is considered a global hotspot for biodiversity, contributing to understanding their taxonomy, diversity and distribution, as well as analysing morphological variations that have led to identification errors in the past. Fieldwork was conducted to make observations and collect fresh material; specimens from national and international herbaria were also examined. Senna section Chamaefistula series Bacillares is represented in the study area by nine species (of which four are endemic to Brazil), including S. pluribracteata F.S.Souto & R.T.Queiroz, a species recently described for the area. All species of the series known from the study area are described and illustrated and a key is provided. Additionally, four names were typified, with two lectotypes and two neotypes being designated here. The results have reinforced the importance of conducting floristic inventories for documenting new species and new occurrences.
Motor “laziness” constrains fixation selection in real-world tasks
Authors: Burlingham Charlie S. , Sendhilnathan Naveen , Komogortsev Oleg , Murdison T. Scott , Proulx Michael J.
Published: March 2024

Humans coordinate their eye, head, and body movements to gather information from a dynamic environment while maximizing reward and minimizing biomechanical and energetic costs. However, such natural behavior is not possible in traditional experiments employing head/body restraints and artificial, static stimuli. Therefore, it is unclear to what extent mechanisms of fixation selection discovered in lab studies, such as inhibition-of-return (IOR), influence everyday behavior. To address this gap, participants performed nine real-world tasks, including driving, visually searching for an item, and building a Lego set, while wearing a mobile eye tracker (169 recordings; 26.6 h). Surprisingly, in all tasks, participants most often returned to what they just viewed and saccade latencies were shorter preceding return than forward saccades, i.e., consistent with facilitation, rather than inhibition, of return. We hypothesize that conservation of eye and head motor effort (“laziness”) contributes. Correspondingly, we observed center biases in fixation position and duration relative to the head’s orientation. A model that generates scanpaths by randomly sampling these distributions reproduced all return phenomena we observed, including distinct 3-fixation sequences for forward versus return saccades. After controlling for orbital eccentricity, one task (building a Lego set) showed evidence for IOR. This, along with small discrepancies between model and data, indicates that the brain balances minimization of motor costs with maximization of rewards (e.g., accomplished by IOR and other mechanisms) and that the optimal balance varies according to task demands. Supporting this account, the orbital range of motion used in each task traded off lawfully with fixation duration.
Cold seep formation from salt diapir–controlled deep biosphere oases
Authors: Chowdhury Anirban , Ventura Gregory T. , Owino Yaisa , Lalk Ellen J. , MacAdam Natasha , Dooma John M. , Ono Shuhei , Fowler Martin , MacDonald Adam , Bennett Robbie , MacRae R. Andrew , Hubert Casey R. J. , Bentley Jeremy N. , Kerr Mitchell J.
Published: March 2024

Deep sea cold seeps are sites where hydrogen sulfide, methane, and other hydrocarbon-rich fluids vent from the ocean floor. They are an important component of Earth’s carbon cycle in which subsurface hydrocarbons form the energy source for highly diverse benthic micro- and macro-fauna in what is otherwise vast and spartan sea scape. Passive continental margin cold seeps are typically attributed to the migration of hydrocarbons generated from deeply buried source rocks. Many of these seeps occur over salt tectonic provinces, where the movement of salt generates complex fault systems that can enable fluid migration or create seals and traps associated with reservoir formation. The elevated advective heat transport of the salt also produces a chimney effect directly over these structures. Here, we provide geophysical and geochemical evidence that the salt chimney effect in conjunction with diapiric faulting drives a subsurface groundwater circulation system that brings dissolved inorganic carbon, nutrient-rich deep basinal fluids, and potentially overlying seawater onto the crests of deeply buried salt diapirs. The mobilized fluids fuel methanogenic archaea locally enhancing the deep biosphere. The resulting elevated biogenic methane production, alongside the upward heat-driven fluid transport, represents a previously unrecognized mechanism of cold seep formation and regulation.
Individual differences in human gaze behavior generalize from faces to objects
Authors: Broda Maximilian Davide , de Haas Benjamin
Published: March 2024

Individuals differ in where they fixate on a face, with some looking closer to the eyes while others prefer the mouth region. These individual biases are highly robust, generalize from the lab to the outside world, and have been associated with social cognition and associated disorders. However, it is unclear, whether these biases are specific to faces or influenced by domain-general mechanisms of vision. Here, we juxtaposed these hypotheses by testing whether individual face fixation biases generalize to inanimate objects. We analyzed >1.8 million fixations toward faces and objects in complex natural scenes from 405 participants tested in multiple labs. Consistent interindividual differences in fixation positions were highly inter-correlated across faces and objects in all samples. Observers who fixated closer to the eye region also fixated higher on inanimate objects and vice versa. Furthermore, the inter-individual spread of fixation positions scaled with target size in precisely the same, non-linear manner for faces and objects. These findings contradict a purely domain-specific account of individual face gaze. Instead, they suggest significant domain-general contributions to the individual way we look at faces, a finding with potential relevance for basic vision, face perception, social cognition, and associated clinical conditions.
The translator as a social activist in the digital age
Authors: Pálušová Martina
Published: March 2024

This article presents a process-oriented, self-reflective study of my work translating a documentary play about anti-government protests in Belarus in 2020. It provides insights into the overlapping roles of translator, social activist and cultural mediator, and reflects on opportunities for collaboration in the digital sphere. Through an analysis of my own notes, interim versions of the translation, editorial revisions, correspondence and conversations with other participants, this article contributes to a deeper understanding of the various roles, stages and relationships found throughout the translation process, as well as the translator’s role in interacting with other stakeholders to express a unanimous protest against violence and oppression made possible by cooperation across borders in the digital sphere.
Animal-assisted psychotherapy in treatment of adults with depressive symptoms: A retrospective quasi-experimental study
Authors: McFalls-Steger Chris , Zottarelli Lisa , Patterson David
Published: March 2024

Animal-assisted psychotherapy (AAP), a subspeciality of animal-assisted therapy (AAT), is a relatively new and innovative treatment modality currently provided to all age groups with various mental and behavioral health issues in different clinical settings. As AAP has become more popular, there is a need to evaluate the use of this approach in therapeutic settings. This study assessed AAP in treating adults with depressive symptoms using a modified version of the Patient Questionnaire Depression Module (mPHQ-9). Secondary data were obtained from a therapy site specializing in AAP in the Denver Metro region of the United States from January 2015 to February 2021. Adult participants 18 years and older were assessed at intake and the approximately 6-month treatment mark. A paired-sample t-test found that AAP resulted in a statistically significant decrease in depressive symptomology, with modified PHQ-9 (mPHQ-9) scores from Intake to Time 2 (t
(50)
= 6.56,
p
< 0.001). The importance of animals in the participants’ decision to seek therapy also significantly influenced the change in depressive symptoms. The total variance explained by the importance of animals pre-treatment on depressive symptoms for adults with AAP was 8.1%,
F
(168.69, 1926.14) = 4.29,
p
= 0.044; moderate effect size (η2 = 0.46) was found. Clinical implications include the function of AAP, which requires a more accurate operational definition and a manualized AAP treatment protocol. AAP is a progressively growing intervention and a promising complementary modality to traditional therapeutic methods for adults with depressive symptoms.
Flat Band and η-Pairing States in a One-Dimensional Moiré Hubbard Model
Authors: Wang 王 R. 冉 , Song 宋 Z. 智
Published: March 2024

A Moiré system is formed when two periodic structures have a slightly mismatched period, resulting in unusual strongly correlated states in the presence of particle-particle interactions. The periodic structures can arise from the intrinsic crystalline order and periodic external field. We investigate a one-dimensional Hubbard model with periodic on-site potential of period n
0, which is commensurate to the lattice constant. For large n
0, the exact solution demonstrates that there is a midgap flat band with zero energy in the absence of Hubbard interaction. Each Moiré unit cell contributes two zero energy levels to the flat band. In the presence of Hubbard interaction, the midgap physics is demonstrated to be well described by a uniform Hubbard chain in which the effective hopping and on-site interaction strength can be controlled by the amplitude and period of the external field. Numerical simulations are performed to demonstrate the correlated behaviors in the finite-sized Moiré Hubbard system, including the existence of an η-pairing state and bound pair oscillation. This finding provides a method to enhance the correlated effect by a spatially periodic external field.
Bayesian real-time classification of multi-messenger electromagnetic and gravitational-wave observations
Authors: Berbel Marina , Miravet-Tenés Miquel , Sharma Chaudhary Sushant , Albanesi Simone , Cavaglià Marco , Magaña Zertuche Lorena , Tseneklidou Dimitra , Zheng Yanyan , Coughlin Michael W , Toivonen Andrew
Published: March 2024

Because of the electromagnetic (EM) radiation produced during the merger, compact binary coalescences with neutron stars may result in multi-messenger observations. In order to follow up on the gravitational-wave (GW) signal with EM telescopes, it is critical to promptly identify the properties of these sources. This identification must rely on the properties of the progenitor source, such as the component masses and spins, as determined by low-latency detection pipelines in real time. The output of these pipelines, however, might be biased, which could decrease the accuracy of parameter recovery. Machine learning algorithms are used to correct this bias. In this work, we revisit this problem and discuss two new implementations of supervised machine learning algorithms, K-nearest neighbors and random forest, which are able to predict the presence of a neutron star and post-merger matter remnant in low-latency compact binary coalescence searches across different search pipelines and data sets. Additionally, we present a novel approach for calculating the Bayesian probabilities for these two metrics. Instead of metric scores derived from binary machine learning classifiers, our scheme is designed to provide the astronomy community well-defined probabilities. This would deliver a more direct and easily interpretable product to assist EM telescopes in deciding whether to follow up on GW events in real time.