bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of energy on protein misfolding and aggregation
Authors: Green Leigh Ann
Published: October 2023

The mechanical deformation of proteins is significantly impacted by thermodynamics.
Investigation of spin–orbit torque switching mechanism in crystalline ferromagnetic semiconductor
Authors: Jana Apu Kumar , Lee Sanghoon
Published: October 2023

We investigated the spin–orbit torque (SOT) switching mechanism of a single layer of crystalline diluted ferromagnetic semiconductor by simulating the current scan hysteresis using the Landau–Lifshitz–Gilbert equation. Our study focuses on the switching of the out-of-plane magnetization component during current scans to provide a detailed understanding of the SOT switching process. The simulation results reveal that the SOT switching strongly depends on the relative strengths of the damping-like torque (DLT) and field-like torque (FLT). Through a systematic analysis, we found that the DLT to FLT ratio required for full SOT switching of the out-of-plane magnetized (GaMn) (AsP) film falls within the range of 0.5–1.0. We also identified a relationship between the DLT to FLT ratio and the linear behavior of the out-of-plane component of magnetization during current scans under a strong in-plane bias field. This suggests that the DLT to FLT ratio of a ferromagnetic film can be directly determined from current scan measurements under a large external field, providing crucial information for developing SOT-based devices.
The effects of polymorphism and lithium intercalation on the hydrogen evolution reaction for the basal planes of MoS2
Authors: Bunting Rhys J. , Caffrey Nuala M.
Published: October 2023

The activity of Li-intercalated MoS2 phases for the hydrogen evolution reaction is investigated using density functional theory. The most stable semiconducting 2H phase, the metallic 1T′ phase, and a polymorphous surface composed of alternating H and T′ phases (1T″) are investigated. The local structure of the MoS2 surface is found to define its reactivity. In all cases, active sites for the hydrogen evolution process are restricted to T-like sulphur sites. Li-intercalation is found to promote hydrogen evolution reaction reactivity for the H phase whilst having little effect on the T phase. While improved compared to the non-intercalated phase, the Li-intercalated H phase MoS2 still has minimal activity for the hydrogen evolution reaction. The same effect of intercalation is also found for another transition metal dichalcogenide, MoSe2. The ability to improve reactivity in this way makes ion intercalation a promising space for designing new 2D catalysts for the hydrogen evolution reaction.
Phase-amplitude reduction and optimal phase locking of collectively oscillating networks
Authors: Mircheski Petar , Zhu Jinjie , Nakao Hiroya
Published: October 2023

We present a phase-amplitude reduction framework for analyzing collective oscillations in networked dynamical systems. The framework, which builds on the phase reduction method, takes into account not only the collective dynamics on the limit cycle but also deviations from it by introducing amplitude variables and using them with the phase variable. The framework allows us to study how networks react to applied inputs or coupling, including their synchronization and phase locking, while capturing the deviations of the network states from the unperturbed dynamics. Numerical simulations are used to demonstrate the effectiveness of the framework for networks composed of FitzHugh–Nagumo elements. The resulting phase-amplitude equations can be used in deriving optimal periodic waveforms or introducing feedback control for achieving fast phase locking while stabilizing the collective oscillations.
A versatile 4 K insert for characterization of the superconducting joints
Authors: Nandawadekar Ajit , Singh Mukhtiar , Kar Soumen
Published: October 2023

A multi-coil superconducting magnet is the heart of any modern Magnetic Resonance Imaging (MRI) scanner. The superconducting magnet in MRI produces a highly homogeneous field (±5 ppm) and stable field (<0.1 ppm/h) in its imaging volume. The temporal field stability depends on the electrical resistance of the inter-coil joints and the electrical resistance of the joint between the coil and the superconducting switch. To establish the joint technology, a 4 K test rig is required for testing the sample joints. This paper briefly discusses the details of the versatile 4 K insert recently developed at IUAC for the characterization of the superconducting joints using the field-decay measurement technique. It can measure the joint resistance up to ∼10−15 Ω in a straight or spiral joint configuration with lengths up to 150 mm. The maximum current that can be induced on the test coil is more than 600 A for the field-decay measurement. The behavior of the joint resistance can also be studied in the presence of a 1.5 T background field. We have characterized many superconducting joints using this versatile 4 K insert. The joints between two different conductors can also be studied using this 4 K insert. The lowest joint resistance measured is 8 × 10−15 Ω at zero field. The joint resistance is also measured in the presence of the background field.
Efficient charging and discharging of a superconducting quantum battery through frequency-modulated driving
Authors: Ge Yangyang , Yu Xiangmin , Xin Wei , Wang Zhimin , Zhang Yu , Zheng Wen , Li Shaoxiong , Lan Dong , Yu Yang
Published: October 2023

The quantum battery (QB), which can potentially store or dispatch energy more efficiently with quantum advantage, has attracted considerable attention lately in the field of quantum thermodynamics. With its quantum advantage, a QB could be charged more efficiently than the classical battery. In this paper, we theoretically and experimentally exploit the frequency-modulated stimulated Raman adiabatic passage (fmod-STIRAP) technique to improve the charging (discharging) efficiency of a cascaded three-level QB that is constituted by a superconducting transmon qutrit. The evolution of the qutrit and its thermodynamic properties are analyzed by carrying out the three-level quantum state tomography on the device. Our experimental results, which are confirmed by numerical simulations, show that the fmod-STIRAP technique yields remarkable advantages in population, ergotropy, and power in the charging (discharging) process.
Engineering DyCrO3 ceramics toward room-temperature high-κ dielectric applications
Authors: Mishra Suryakanta , Choudhury Debraj
Published: October 2023

The search for a high-κ dielectric material that combines a high dielectric constant (ϵ′) and low dielectric loss is very crucial because of its widespread use in gate dielectrics to avoid the leakage current that arises due to continued miniaturization of present SiO2-based metal-oxide semiconductor field-effect transistor devices. RCrO3 (R is a rare-earth ion) materials have been at the center of interest because of their intriguing ferroelectric and magnetic properties, as well as their room-temperature colossal dielectric constant (CDC) values. Although CDC (ϵ′∼104) in RCrO3 materials is quite common, it is unsuitable for device applications since it is associated with a larger dielectric loss value (tan δ∼7 at 11 kHz). Here we have focused on polycrystalline DyCrO3, prepared using multiple synthesis techniques, and thoroughly investigated the origin and tuning of the various dielectric relaxations that give rise to CDC and large dielectric loss values. A clear understanding of the origin of dielectric relaxations enables us to design a specially synthesized DyCrO3 (SPS-DCO) in which the extrinsic dielectric relaxations driven large dielectric loss values can be completely suppressed and which is found to be associated with optimized high-κ dielectric properties [ϵ′∼130, tan δ∼0.06, and temperature coefficient of dielectric constant (TCϵ) ∼ 2280 ppm/K at 11 kHz, 300 K]. The only remaining intrinsic Debye-type dielectric relaxation in SPS-DCO arises due to electric-field-assisted charge hopping among various valences of Cr (investigated using x-ray photoelectron spectroscopy) that presently limits the lowest attainable loss value.
High external quantum efficiency monolayer MoS2(1−x)Se2x phototransistor with alloying-induced near-infrared absorption
Authors: Li Yuhan , Li Qiaoqiao , Wang Zichen , Huang Zhiyu , Zhu Juntong , Channa Ali Imran , Cui Fan , Xu Hao , Li Xiao , Zhou Liujiang , Zou Guifu
Published: October 2023

Due to intriguing electrical and optical properties, two-dimensional MoS2 has gained significant attention and emerged as a promising material in photonic and optoelectronic fields. Nevertheless, the intrinsic optical absorption of monolayer MoS2 is limited in the visible region only, restricting applications toward near-infrared (NIR) photodetection. Herein, we engineered the optical properties of MoS2 via alloying with Se to extend its optical absorption to the NIR region, and the phototransistor was fabricated based on monolayer MoS2(1−x)Se2x (x = ∼0.1). When under 780 nm (∼1.59 eV) illumination, the device delivered a photoresponsivity of 75.38 A/W, a specific detectivity of ∼1012 Jones, and an external quantum efficiency up to 11 230%. Additionally, it was revealed by density functional theory calculations that NIR absorption originated from the transition of valence states of sulfur vacancy (Vs) interband energy states between +1 and 0, providing an interband energy level of 1.58 eV away from the conduction band minima. Moreover, alloying of Se can suppress deep-level defects formed via Vs, further boosting device performance. This work has demonstrated high-performance NIR phototransistors based on ternary monolayer MoS2(1−x)Se2x, providing both a viable solution and fundamental mechanisms for NIR-blind MoS2 with extended optical absorption.
Picosecond pulsed 532 nm laser system for roughening and secondary electron yield reduction of inner surfaces of up to 15 m long tubes
Authors: Bez Elena , Himmerlich Marcel , Beaudou Benoit , Reascos Portilla Ana Karen , Wackerow Stefan , Rimoldi Martino , Pfeiffer Stephan , Wiesendanger Markus , Benabid Fetah , Taborelli Mauro , Abdolvand Amin , Chiggiato Paolo
Published: October 2023

Laser-induced surface structuring is a promising method to suppress electron mulitpacting in the vacuum pipes of particle accelerators. Electrons are scattered inside the rough surface structure, resulting in a low Secondary Electron Yield (SEY) of the material. However, laser processing of internal pipe surfaces with a large aspect ratio is technologically challenging in terms of laser beam guidance and focusing. We present a 532 nm ultrashort-pulse laser setup to process the inner parts of 15 m long beam vacuum tubes of the Large Hadron Collider (LHC). Picosecond pulses at a repetition rate of 200 kHz are guided through an optical fiber toward an inchworm robot traveling inside the beam pipe. The system was installed, characterized, and tested for reliability. First surface treatments achieved the required scan precision. Cu2O-dominated nano-features were observed when processing at high average laser power (5 W) and slow scanning speed (5 mm s−1) in nitrogen flow, and the maximum SEY of copper was decreased from 2.1 to 0.7.
Passive scalar small-scale anisotropy and mixing characteristics in magnetohydrodynamic turbulent channel flow
Authors: Pouransari Zeinab
Published: October 2023

In wall-bounded turbulent flows, both velocity and scalar fluctuations exhibit inhomogeneity and anisotropy. This study investigates the statistical properties of the small-scale scalar fluctuations in a turbulent channel flow at Reτ≈585 using direct numerical simulations with and without a magnetic field. The influence of the Hartmann, Ha, and Prandtl, Pr, numbers on turbulent velocity and passive scalar fields is examined at Ha=0, 20, and 40 and Pr=0.7 and 1.4. Small-scale dynamics of the passive scalar and velocity fields are studied, analyzing their probability density functions and higher-order moments, as well as their gradients. We observed that the magnetic field substantially changes flow dynamics such as the typical cliff-and-ramp type structures. The presence of the magnetic field led to statistical anisotropy, even at small-scale gradient fields. The findings reveal that the skewness of the normal derivative of scalar fluctuations remains at the order of 2. We investigated mixing characteristics by analyzing scalar dissipation rates. Scalar dissipation rates near the wall remain close to unity and decrease sharply toward the channel center, reaching a minimum value. Moreover, an increase in scalar dissipation rates leads to a decrease in the corresponding mixing timescale of the flow. This could suggest a connection between an increase in the Lorentz force and potential adjustments in the mixing timescale, potentially contributing to enhance overall mixing. Additionally, we argue that combined effects of strong intermittency and persistency of anisotropy at small scales can influence the mixing characteristics of magnetohydrodynamic turbulent flow.
Thermal transport across TiO2–H2O interface involving water dissociation: Ab initio-assisted deep potential molecular dynamics
Authors: Li Zhiqiang , Wang Jian , Yang Chao , Liu Linhua , Yang Jia-Yue
Published: October 2023

Water dissociation on TiO2 surfaces has been known for decades and holds great potential in various applications, many of which require a proper understanding of thermal transport across the TiO2–H2O interface. Molecular dynamics (MD) simulations play an important role in characterizing complex systems’ interfacial thermal transport properties. Nevertheless, due to the imprecision of empirical force field potentials, the interfacial thermal transport mechanism involving water dissociation remains to be determined. To cope with this, a deep potential (DP) model is formulated through the utilization of ab initio datasets. This model successfully simulates interfacial thermal transport accompanied by water dissociation on the TiO2 surfaces. The trained DP achieves a total energy accuracy of ∼238.8 meV and a force accuracy of ∼197.05 meV/Å. The DPMD simulations show that water dissociation induces the formation of hydrogen bonding networks and molecular bridges. Structural modifications further affect interfacial thermal transport. The interfacial thermal conductance estimated by DP is ∼8.54 × 109 W/m2 K, smaller than ∼13.17 × 109 W/m2 K by empirical potentials. The vibrational density of states (VDOS) quantifies the differences between the DP model and empirical potentials. Notably, the VDOS disparity between the adsorbed hydrogen atoms and normal hydrogen atoms demonstrates the influence of water dissociation on heat transfer processes. This work aims to understand the effect of water dissociation on thermal transport at the TiO2–H2O interface. The findings will provide valuable guidance for the thermal management of photocatalytic devices.
Molecular dynamics-driven global potential energy surfaces: Application to the AlF dimer
Authors: Liu Xiangyue , Wang Weiqi , Pérez-Ríos Jesús
Published: October 2023

In this work, we present a full-dimensional potential energy surface for AlF–AlF. We apply a general machine learning approach for full-dimensional potential energy surfaces, employing an active learning scheme trained on ab initio points, whose size grows based on the accuracy required. The training points are selected based on molecular dynamics simulations, choosing the most suitable configurations for different collision energy and mapping the most relevant part of the potential energy landscape of the system. The present approach does not require long-range information and is entirely general. As a result, it is possible to provide the full-dimensional AlF–AlF potential energy surface, requiring ≲0.01% of the configurations to be calculated ab initio. Furthermore, we analyze the general properties of the AlF–AlF system, finding critical differences with other reported results on CaF or bi-alkali dimers.
WS2-based inorganic triboelectric nanogenerators with light-enhanced output and excellent anti-aging ability
Authors: Sun Yue-Hua , Song Wei-Zhi , Sun De-Jun , Zhang Tong , Zhang Duo-Shi , Zhang Jun , Ramakrishna Seeram , Long Yun-Ze
Published: October 2023

Conventional triboelectric nanogenerators (TENGs) usually use polymer as friction layers, because polymer usually has large electronegativity differences and reliable frictional recovery properties. In recent years, inorganic material-based TENG has drawn attention due to its much higher resistance to high-temperature aging, light aging, and fatigue resistance than polymer. However, the performance of TENG with aging has not been fully studied. In this work, pure inorganic TENG based on WS2 and ITO glass was prepared, achieving a short-current (ISC) of 0.3 μA and an open voltage (VOC) of 30 V in the dark. Particularly, the current output of the nanogenerator could be enhanced to 0.61 μA under illumination. In addition, accelerated aging experiments indicated that the inorganic nanogenerator had a good improvement in performance degradation compared to most conventional polymeric nanogenerators. Based on this work, WS2-based inorganic TENGs have stability advantages and may be fully used in a wider range of environments.
Effects of 63 MeV proton irradiation on the performance of MWIR InGaAs/InAsSb nBn photodetectors
Authors: Newell A. T. , Logan J. V. , Carrasco R. A. , Hains C. P. , Ariyawansa G. , Duran J. M. , Balakrishnan G. , Maestas D. , Morath C. P. , Webster P. T.
Published: October 2023

An investigation into the effects of 63 MeV proton irradiation on high-sensitivity mid-wave infrared InGaAs/InAsSb nBn devices is performed. Three different structures with various absorber region doping profiles are irradiated and characterized to assess their impact on performance degradation. Minority carrier lifetime is measured using time-resolved photoluminescence and lifetime damage factors are assessed. The majority carrier concentration is determined via capacitance–voltage measurements and dopant introduction rates are calculated. An analysis of dark current density is performed using these material parameters, revealing a reduction in mobility with proton fluence and the emergence of a proton-induced trap energy level. Quantum efficiency is calculated at each proton fluence, and quantum efficiency damage factors show that the graded doping structure exhibits the least reduction of quantum efficiency with dose, attributed to its effective mobility enhancement. Conclusively, detector sensitivity, assessed via shot-noise limited noise-equivalent irradiance, shows that the graded doping structure is the least susceptible to high energy proton irradiation-induced performance degradation.
Bipolar thermoelectrical SQUIPT (BTSQUIPT)
Authors: Guarcello C. , Citro R. , Giazotto F. , Braggio A.
Published: October 2023

We theoretically study the quasiparticle current behavior of a thermally biased bipolar thermoelectrical superconducting quantum interference proximity transistor, formed by a normal metal wire embedded in a superconducting ring and tunnel-coupled to a superconducting probe. In this configuration, the superconducting gap of the wire can be modified through an applied magnetic flux. We analyze the thermoelectric response as a function of magnetic flux, at fixed temperatures, in the case of a device made of the same superconductor. We demonstrate magnetically controllable, bipolar thermoelectric behavior and discuss optimal working conditions by looking at the thermoelectric power and other figures of merit of the device.
Particle-resolved direct numerical simulation of particle-laden turbulence modulation with high Stokes number monodisperse spheres
Authors: Su Weite , Zhang Huahai , Fu Shaotong , Xiang Xing , Wang Limin
Published: October 2023

Graphic processing units (GPU)-accelerated direct numerical simulations of particle–fluid systems based on lattice Boltzmann method combined with discrete element method are successfully performed. This method is validated to be accurate and efficient in the four-way coupling simulation of particle–fluid systems. Particle-laden homogeneous isotropic turbulence under particle size dp=30.1η (the Kolmogorov length scale), a wide range of solid volume fraction ϕV=2%−20% and particle Stokes number St=503.87−50 387 are systematically studied. The additional energy dissipation rate εaddi induced by particles is quantitatively calculated. One criterion for turbulence enhancement or attenuation based on energy balance is proposed and successfully used in different particle-laden turbulence. The relative magnitude of two-way coupling rate ψ and particle-induced dissipation εaddi is the direct factor determining the modulation effect on turbulence. Turbulence laden with high Stokes number particles is enhanced. Turbulence laden with high volume fraction particles transited rapidly from enhancement to attenuation, which is attributed to the more rapid decay of ψ relative to εaddi in the freely decaying turbulence.
Quantitative characterization of current-induced self-spin–orbit torques in a perpendicularly magnetized (Ga,Mn)As single thin film
Authors: Wang Chenda , Jiang Miao , Ohya Shinobu , Tanaka Masaaki
Published: October 2023

Quantitative characterizations of the current-induced spin–orbit torques (SOTs) are vitally important for both fundamental understanding and practical applications of SOT-based spintronic devices. Here, we study effective SOT magnetic fields in a (Ga,Mn)As single film with perpendicular magnetic anisotropy, where we can achieve highly efficient full-magnetization switching with a small critical switching current density Jc as low as 105 A/cm2. Using second harmonic Hall measurements, we estimate the SOT effective fields; the damping-like SOT effective field HDL and the field-like SOT effective field HFL are 22.1 and 18.1 Oe, respectively, at 4 K when a current of 1.43 × 105 A/cm2 is applied to the device. Based on this result, we estimate the corresponding spin-torque efficiencies ξDL and ξFL to be 1.32 and 1.08, respectively, which are one order of magnitude higher than those in conventional metal systems. The high efficiency can be partly attributed to the simple single-functional-layer structure, which can avoid the loss from spin scattering at the interface between different functional layers as observed in conventional SOT devices. Our findings will lay the foundation for studying SOT physics and devices based on ferromagnetic semiconductors.
Analysis of flow diffusion of secondary lubricant in water-lubricated bearings
Authors: Liang Qingchen , Liang Peng , Guo Feng , Zhang Xiaohan , Jin Lei , Jiang Fulin , Li Shuyi
Published: October 2023

To reduce the lubrication failure of water-lubricated bearings under short-term harsh conditions, preliminary experiments have shown that temporarily supplying a small amount of lubricating oil into a bearing as a secondary lubricant can improve the load capacity of the water film therein. However, the physical flow and diffusion state of this secondary lubricant (oil) in water are unclear. Therefore, a mixed lubrication model and a volume-of-fluid model are incorporated to study the diffusion behavior of a small amount of lubricating oil in a water-lubricated bearing. The results show that there is a backflow effect in the local area inside the bearing, where the fluid velocity is in the opposite direction to the linear velocity of the shaft. This backflow effect intensifies with increasing eccentricity ratio, which enlarges the oil-free zone in the middle part of the bearing. In the convergence area at the water inlet end of the bearing, the water supply pressure and backflow effect prevent the lubricating oil from escaping. Increasing the shaft speed has a positive effect on the diffusion of the oil and the load capacity of the fluid. To enhance the assisted lubrication effect of the oil, the oil injection port should be set in the loading zone to avoid the backflow zone. This research provides some fundamental data for reducing the friction and wear of water-lubricated bearings under harsh conditions.
Temperature and field dependencies of current leakage mechanisms in IrOx contacts on InAlN/GaN heterostructures
Authors: Eisner Savannah R. , Senesky Debbie G.
Published: October 2023

This Letter reports on the mechanisms of reverse leakage current transport in InAlN/GaN heterostructure Schottky diodes with intentionally oxidized iridium oxide (IrOx) contacts across a wide temperature range. Current–voltage characteristics were experimentally measured from 25 to 500 °C (≈ 300 to 773 K). Three distinct regions in the reverse bias regime of operation and their corresponding dominant current transport mechanisms are identified. A trap-assisted tunneling mechanism is observed at low reverse bias, and trap energy levels are between 1.12 and 1.99 eV. At medium reverse bias, Poole–Frenkel emission is decomposed into low-field, mid-field, and high-field regions and the related trap activation energies vary from 0.38 to 2.04 eV. At high reverse bias, the Fowler–Nordheim model is applied and the effective barrier height to tunneling is 0.78 eV. The model of the reverse leakage current constructed using the parameters associated with these transport mechanisms closely aligns with the experimental data and supports the advancement of high-temperature electronics based on IrOx -gated InAlN/GaN heterostructure technology.
Leaf manganese and phenolics as proxies of soil acidification and phosphorus acquisition mechanisms in lentil cultivars on alkaline soil
Authors: Theologidou Georgia S. , Ipsilantis Ioannis , Tsialtas Ioannis T.
Published: October 2023

Leaf manganese (Mn) concentration has been used as a proxy for root exudation and phosphorus (P) uptake under controlled conditions, but there are limited field studies that confirm its validity. On an alkaline, P-poor soil, four lentil cultivars (‘Samos’, ‘Thessaly’, ‘Flip’, ‘Algeria’) received two P rates (0 and 26.2 kg P ha−1), for two growing seasons, to study whether aboveground assessments [leaf P, Mn, phenolic concentration (TPhe)] can approximate rhizosphere physiological traits related to P acquisition [soil acidification (ΔpH), arbuscular mycorrhizal fungi (AMF) colonisation, acid phosphatase activity (APase)]. Phosphorus addition had no effect on the determined traits. Cultivars differed in leaf P, Mn, TPhe and AMF, but there was no clear pattern relating aboveground traits to rhizosphere traits related to P acquisition, thus not confirming that leaf Mn can be a proxy of root exudation. Of three growth stages [V 7–8, R1 (first bloom), R4 (flat pod)], R1 seemed to be critical, showing the highest leaf P, ΔpH, AMF and TPhe. Precipitation and temperatures over the growing season were determinants of lentil responses affecting rhizosphere activity, soil P availability and finally leaf traits. In conclusion, in lentil on alkaline and P-limiting soils, high leaf Mn and phenolic concentration are not reliable indicators of rhizosphere P-acquiring mechanisms.
Mapping the probability of wildland fire occurrence in Central America, and identifying the key factors
Authors: Valdez Miguel Conrado , Chen Chi-Farn , Chicas Santos Daniel , Mizoue Nobuya
Published: October 2023

Background Wildland fires are part of the ecology of forests in Central America. Nevertheless, limited understanding of fire probability and the factors that influence it hinder the planning of intervention strategies. Aims This research combined climatic, anthropogenic and vegetation factors to identify wildland fire probability and determine the most relevant factors. Methods We performed an exploratory analysis to identify important factors and integrated them with fire observations using random forest. We then used the most relevant factors to predict wildland fire occurrence probability and validated our results using different measures. The results demonstrated satisfactory agreement with the independent data. Key results Central regions of Honduras, northern Guatemala and Belize have a very high probability of wildland fire occurrence. Human imprint and extreme climatic conditions influence wildland fire probability in Central America. Conclusions Using random forest, we identified the major influencing factors and areas with a high probability of wildland fire occurence in Central America. Implications Results from this research can support regional organisations in applying enhanced strategies to minimise wildland fires in high-probability areas. Additional efforts may also include using future climate change scenarios and increasing the time frame to evaluate the influence of teleconnection patterns.
The effects of local interventions on global technological change through spillovers: A modeling framework and application to the road-freight sector
Authors: Noll Bessie , Steffen Bjarne , Schmidt Tobias S.
Published: October 2023

To address global sustainability challenges, (public) policy interventions are needed to induce or accelerate technological change. While most policy interventions occur on the local level, their innovation effects can spill over to other jurisdictions, potentially having global impact. These spillovers can increase or reduce the incentive for interventions. Lacking to date are computational models that capture these spillover dynamics. Here, we devise a conceptual and methodological approach to quantify ex ante the effects of local demand-side interventions on global competition between incumbent and novel technologies. We introduce two factors that moderate global spillovers—relative size of selection environments and relative innovation potential of competing technologies. Our approach incorporates both factors in a techno-economic discrete choice model that evaluates technology competition over time through endogenized technological learning. We apply this modeling framework to the case of road freight. Different demand-pull interventions and shocks are modeled to assess spillover effects. In the case of road freight, electric vehicles experience growth in most application segments but can still be accelerated substantially through public policy intervention—spillovers occur if strong public interventions are introduced in large regions or in multiple combined regions under club policy interventions. These findings are discussed in the context of club policy interventions and a modeled geopolitical shock in China. A full sensitivity analysis of model input parameters and intervention or shock dynamics reveals high model robustness. Finally, we discuss the implications of the road-freight case study as it might inform the progress of other niche technologies in transitioning sectors.
Identification of the lipodepsipeptide selethramide encoded in a giant nonribosomal peptide synthetase from aBurkholderiabacterium
Authors: Romanowski Sean B. , Lee Sanghoon , Kunakom Sylvia , Paulo Bruno S. , Recchia Michael J. J. , Liu Dennis Y. , Cavanagh Hannah , Linington Roger G. , Eustáquio Alessandra S.
Published: October 2023

Bacterial natural products have found many important industrial applications. Yet traditional discovery pipelines often prioritize individual natural product families despite the presence of multiple natural product biosynthetic gene clusters in each bacterial genome. Systematic characterization of talented strains is a means to expand the known natural product space. Here, we report genomics, epigenomics, and metabolomics studies ofBurkholderiasp. FERM BP-3421, a soil isolate and known producer of antitumor spliceostatins. Its genome is composed of two chromosomes and two plasmids encoding at least 29 natural product families. Metabolomics studies showed that FERM BP-3421 also produces antifungal aminopyrrolnitrin and approved anticancer romidepsin. From the orphan metabolome features, we connected a lipopeptide of 1,928 Da to an 18-module nonribosomal peptide synthetase encoded as a single gene in chromosome 1. Isolation and structure elucidation led to the identification of selethramide which contains a repeating pattern of serine and leucine and is cyclized at the side chain oxygen of the one threonine residue at position 13. A (R)-3-hydroxybutyric acid moiety decorates theN-terminal serine. Initial attempts to obtain deletion mutants to probe the role of selethramide failed. After acquiring epigenome (methylome) data for FERM BP-3421, we employed a mimicry by methylation strategy that improved DNA transfer efficiency. Mutants defective in selethramide biosynthesis showed reduced surfactant activity and impaired swarming motility that could be chemically complemented with selethramide. This work unveils a lipopeptide that promotes surface motility, establishes improved DNA transfer efficiency, and sets the stage for continued natural product identification from a prolific strain.
Mechanics-based classification rule for plants
Authors: Kanahama Tohya , Sato Motohiro
Published: October 2023

The height of thick and solid plants, such as woody plants, is proportional to two-thirds of the power of their diameter at breast height. However, this rule cannot be applied to herbaceous plants that are thin and soft because the mechanisms supporting their bodies are fundamentally different. This study aims to clarify the rigidity control mechanism resulting from turgor pressure caused by internal water in herbaceous plants to formulate the corresponding scaling law. We modeled a herbaceous plant as a cantilever with the ground side as a fixed end, and the greatest height was formulated considering the axial tension force from the turgor pressure. The scaling law describing the relationship between the height and diameter in terms of the turgor pressure was theoretically derived. Moreover, we proposed a plant classification rule based on stress distribution.
The metabolomic physics of complex diseases
Authors: Wu Shuang , Liu Xiang , Dong Ang , Gragnoli Claudia , Griffin Christopher , Wu Jie , Yau Shing-Tung , Wu Rongling
Published: October 2023

Human diseases involve metabolic alterations. Metabolomic profiles have served as a vital biomarker for the early identification of high-risk individuals and disease prevention. However, current approaches can only characterize individual key metabolites, without taking into account the reality that complex diseases are multifactorial, dynamic, heterogeneous, and interdependent. Here, we leverage a statistical physics model to combine all metabolites into bidirectional, signed, and weighted interaction networks and trace how the flow of information from one metabolite to the next causes changes in health state. Viewing a disease outcome as the consequence of complex interactions among its interconnected components (metabolites), we integrate concepts from ecosystem theory and evolutionary game theory to model how the health state-dependent alteration of a metabolite is shaped by its intrinsic properties and through extrinsic influences from its conspecifics. We code intrinsic contributions as nodes and extrinsic contributions as edges into quantitative networks and implement GLMY homology theory to analyze and interpret the topological change of health state from symbiosis to dysbiosis and vice versa. The application of this model to real data allows us to identify several hub metabolites and their interaction webs, which play a part in the formation of inflammatory bowel diseases. The findings by our model could provide important information on drug design to treat these diseases and beyond.
Dynamic context-dependent regulation of auxin feedback signaling in synthetic gene circuits
Authors: Avdovic Merisa , Garcia-Navarrete Mario , Ruiz-Sanchis Diego , Wabnik Krzysztof
Published: October 2023

Phytohormone auxin plays a key role in regulating plant organogenesis. However, understanding the complex feedback signaling network that involves at least 29 proteins in Arabidopsis in the dynamic context remains a significant challenge. To address this, we transplanted an auxin-responsive feedback circuit responsible for plant organogenesis into yeast. By generating dynamic microfluidic conditions controlling gene expression, protein degradation, and binding affinity of auxin response factors to DNA, we illuminate feedback signal processing principles in hormone-driven gene expression. In particular, we recorded the regulatory mode shift between stimuli counting and rapid signal integration that is context-dependent. Overall, our study offers mechanistic insights into dynamic auxin response interplay trackable by synthetic gene circuits, thereby offering instructions for engineering plant architecture.
Vestiges of impact-driven three-phase mixing in the chemistry and structure of Earth’s mantle
Authors: Korenaga Jun , Marchi Simone
Published: October 2023

Highly siderophile elements (HSEs; namely Ru, Rh, Pd, Re, Os, Ir, Pt, and Au) in Earth’s mantle require the addition of metals after the formation of Earth’s core. Early, large collisions have the potential to deliver metals, but the details of their mixing with Earth’s mantle remain unresolved. As a large projectile disrupts and penetrates Earth’s mantle, a fraction of its metallic core may directly merge with Earth’s core. Ensuing gravitational instabilities remove the remaining projectile’s core stranded in Earth’s mantle, leaving the latter deprived of HSEs. Here, we propose a framework that can efficiently retain the metallic components during large impacts. The mechanism is based on the ubiquitous presence of a partially molten region in the mantle beneath an impact-generated magma ocean, and it involves rapid three-phase flow with solid silicate, molten silicate, and liquid metal as well as long-term mixing by mantle convection. In addition, large low-shear-velocity provinces in the lower mantle may originate from compositional heterogeneities resulting from the proposed three-phase flow during high-energy collisions.
Associations of inflammatory polyarthritis with clinical and radiological findings of temporomandibular disorders
Authors: Oksanen Sari , Sipilä Kirsi , Heliövaara Markku , Suominen Anna Liisa , Huumonen Sisko
Published: October 2023

Objective: To evaluate the association of different forms of inflammatory polyarthritis with clinical signs of temporomandibular disorders (TMD) and radiological findings in temporomandibular joint (TMJ), based on a nationwide health survey in Finland. The aim was also to assess the presence of clinical and radiological TMD findings in subjects with increased risk for developing rheumatoid arthritis (RA).
Material and methods: Anationally representative sample included 6331 Finnish adults who participated in the Health 2000 Survey (BRIF8901). Subjects were examined for signs of TMD, findings in panoramic radiograph of TMJ, musculoskeletal health and serology (rheumatoid factor, RF, and anti-cyclic citrullinated peptide, aCCP).
Results: Sixty-four percent of seronegative RAand 60% of seropositive RAsubjects had at least one sign of TMD. While adjusting for confounding factors (gender, age, dentures and smoking history), RAwas significantly associated with crepitation and abnormal radiological findings in TMJ. Seronegative RAwas also associated with restricted mouth opening. Systemic autoimmunity associated with RA(“at risk of RA”) was not associated with clinical or radiological TMD findings.
Conclusions: Clinical and radiological findings of TMD are more prevalent among subjects with inflammatory polyarthritis than among the population in general in the Finnish adult population.
The TMEM192-mKeima probe specifically assays lysophagy and reveals its initial steps
Authors: Shima Takayuki , Ogura Monami , Matsuda Ruriko , Nakamura Shuhei , Jin Natsuko , Yoshimori Tamotsu , Kuma Akiko
Published: October 2023

Membrane rupture of lysosomes results in leakage of their contents, which is harmful to cells. Recent studies have reported that several systems contribute to the repair or elimination of damaged lysosomes. Lysophagy is a type of selective autophagy that plays a crucial role in the lysosomal damage response. Because multiple pathways are involved in this response, an assay that specifically evaluates lysophagy is needed. Here, we developed the TMEM192-mKeima probe to evaluate lysophagy. By comparing the use of this probe with the conventional galectin-3 assay, we showed that this probe is more specific to lysophagy. Using TMEM192-mKeima, we showed that TFEB and p62 are important for the lysosomal damage response but not for lysophagy, although they have previously been considered to be involved in lysophagy. We further investigated the initial steps in lysophagy and identified UBE2L3, UBE2N, TRIM10, 16, and 27 as factors involved in it. Our results demonstrate that the TMEM192-mKeima probe is a useful tool for investigating lysophagy.
Energy Landscape and Phase Competition of CsV3Sb5, CsV6Sb6 and TbMn6Sn6-Type Kagome Materials
Authors: Cai 蔡 Guanghui 光辉 , Jiang 姜 Yutao 昱韬 , Zhou 周 Hui 辉 , Yu 喻 Ze 泽 , Jiang 蒋 Kun 坤 , Shi 石 Youguo 友国 , Meng 孟 Sheng 胜 , Liu 刘 Miao 淼
Published: October 2023

Finding viable Kagome lattices is vital for materializing novel phenomena in quantum materials. In this study, we performed element substitutions on CsV3Sb5 with space group P6/mmm, TbMn6Sn6 with space group P6/mmm, and CsV6Sb6 with space group

R

3
¯

m

, as the parent compounds. Totally 4158 materials were obtained through element substitutions, and these materials were then calculated via density functional theory in high-throughput mode. Afterwards, 48 materials were identified with high thermodynamic stability (E
hull < 5 meV/atom). Furthermore, we compared the thermodynamic stability of three different phases with the same elemental composition and predicted some competing phases that may arise during material synthesis. Finally, by calculating the electronic structures of these materials, we attempted to identify patterns in the electronic structure variations as the elements change. This study provides guidance for discovering promising AM3X5/AM6X6 Kagome materials from a vast phase space.
Theory and optimisation of radiative recombination in broken-gap InAs/GaSb superlattices
Authors: Murphy Cónal , O’Reilly Eoin P , Broderick Christopher A
Published: October 2023

We present a theoretical analysis of mid-infrared radiative recombination in InAs/GaSb superlattices (SLs). We employ a semi-analytical plane wave expansion method in conjunction with an 8-band

k

⋅

p

Hamiltonian to compute the SL electronic structure, paying careful attention to the identification and mitigation of spurious solutions. The calculated SL eigenstates are used directly to compute spontaneous emission spectra and the radiative recombination coefficient

B

. We elucidate the origin of the relatively large

B

coefficients in InAs/GaSb SLs which, despite the presence of spatially indirect (type-II-like) carrier confinement, are close to that of bulk InAs and compare favourably to those calculated for mid-infrared type-I pseudomorphic and metamorphic quantum well structures having comparable emission wavelengths. Our analysis explicitly quantifies the roles played by carrier localisation (specifically, partial delocalisation of bound electron states) and miniband formation (specifically, miniband occupation and optical selection rules) in determining the magnitude of

B

and its temperature dependence. We perform a high-throughput optimisation of the room temperature

B

coefficient in InAs/GaSb SLs across the 3.5–7 

μ

m wavelength range, quantifying the dependence of

B

on the relative thickness of the electron-confining InAs and hole-confining GaSb layers. This analysis provides guidance for the growth of optimised SLs for mid-infrared light emitters. Our results, combined with the expected low non-radiative Auger recombination rates in structures having spatially indirect electron and hole confinement, corroborate recently observed high output power in prototype InAs/GaSb SL inter-band cascade light-emitting diodes.
Mid-infrared thermal radiation resonating with longitudinal-optical like phonon from n++-doped GaN–semi-insulating GaN grating structure
Authors: Lin Bojin , Aye Hnin Lai Lai , Ueno Kohei , Fujioka Hiroshi , Miyake Hideto , Ishitani Yoshihiro
Published: October 2023

The mid-infrared emission mechanism of line-and-space structures of metallic plates on dielectric materials is substantiated using high conductive n-doped (n++-) GaN–semi-insulating (SI-) GaN microstripe structures on an SI-GaN epitaxial layer, which was veiled when using line-and-space structures of Au plates. The present structure exhibits a few thermal emission lines originating from electric dipoles resonating with the coherent longitudinal optical (LO) phonon-like lattice vibration, which are formed by the local depolarization electric field in the surface n++-GaN/SI-GaN/n++-GaN regions. The energies of the LO-phonon-like modes shift from the original LO-phonon energy of GaN to the lower energy region, which contrasts with the LO-phonon resonant emission from the microstructures on GaAs. These emission lines have another notable feature, i.e. the observed peak energies are independent of the polar emission angle for both s- and p-polarizations, unlike the emissions by surface phonon polaritons showing a significant directive nature of peak energies. The results show that each peak energy of the present emission lines is positioned at the zero-point of the real part of the electric permittivity comprising the components of the transverse optical phonon and other electric dipoles induced by the LO-like modes, excluding the target mode. The significant peak-energy shift of the LO-like phonons is applicable to materials with wide Reststrahlen bands, which contrasts with that of the nearly LO-phonon resonating feature of materials with narrow Reststrahlen bands, such as GaAs. The peak energy shift depending on the emission direction is observed for Au–GaN stripe structures. This property is ascribed to the imperfect Au/GaN interface with surface states through the theoretical analysis of the modified electric permittivity in the surface region, numerical simulation of the local electric field via finite-difference time-domain calculation, and experimental studies on a Ti–GaN structure and emission peaks originating from an LO-like phonon of the α-Al2O3 substrate.
Search for an interaction mediated by axion-like particles with ultracold neutrons at the PSI
Authors: Ayres N J , Bison G , Bodek K , Bondar V , Bouillaud T , Chanel E , Chiu P-J , Clement B , Crawford C B , Daum M , Doorenbos C B , Emmenegger S , Fertl M , Flaux P , Griffith W C , Harris P G , Hild N , Kasprzak M , Kirch K , Kletzl V , Koss P A , Krempel J , Lauss B , Lefort T , Mohanmurthy P , Naviliat-Cuncic O , Pais D , Piegsa F M , Pignol G , Rawlik M , Rienäcker I , Ries D , Roccia S , Rozpedzik D , Schmidt-Wellenburg P , Severijns N , Shen B , Svirina K , Tavakoli Dinani R , Thorne J A , Touati S , Weis A , Wursten E , Yazdandoost N , Zejma J , Ziehl N , Zsigmond G
Published: October 2023

We report on a search for a new, short-range, spin-dependent interaction using a modified version of the experimental apparatus used to measure the permanent neutron electric dipole moment at the Paul Scherrer Institute. This interaction, which could be mediated by axion-like particles, concerned the unpolarized nucleons (protons and neutrons) near the material surfaces of the apparatus and polarized ultracold neutrons stored in vacuum. The dominant systematic uncertainty resulting from magnetic-field gradients was controlled to an unprecedented level of approximately 4 pT cm−1 using an array of optically-pumped cesium vapor magnetometers and magnetic-field maps independently recorded using a dedicated measurement device. No signature of a theoretically predicted new interaction was found, and we set a new limit on the product of the scalar and the pseudoscalar couplings

g
s

g
p

λ
2

<
8.3
×

10

−
28

m2 (95% C.L.) in a range of 5 µm

<
λ
<
25

 mm for the monopole–dipole interaction. This new result confirms and improves our previous limit by a factor of 2.7 and provides the current tightest limit obtained with free neutrons.