bluuebunny/crossref_metadata_2025 huggingface dataset:
New Hydrophobic Treatment for the Protection of Gypsum Artifacts
Authors: Bergamonti Laura , Verza Edoardo , Di Virgilio Gilberto , Muroni Giacomo , Michelini Elena , Ferretti Daniele , Lottici Pier Paolo , Graiff Claudia
Published: September 2024

Gypsum has been widely used in traditional and monumental architecture in many countries of the Mediterranean area; however, due to its low water resistance and low mechanical strength, it can be subject to physical, chemical and biological degradation. To improve the preservation of gypsum-based plaster artifacts, a new hybrid inorganic-organic hydrophobic treatment is proposed in this work. This treatment is based on nanometric magnesium hydroxide (Mg(OH)₂) and organically modified silica (OrMoSil), a class of materials with intermediate performances between ceramic materials and polymers. The behaviour of the product was verified both as a protective on gypsum surface, as well as a consolidant added to the mixture of gypsum-based plasters. The treatment does not alter the aesthetic appearance of the surface, as verified through colorimetric analysis. As demonstrated by capillary water absorption and static contact angle measurements, the new hydrophobic protective coating proved to be very effective. Moreover, the new treatment is effective as a consolidant, leading to an improvement of the mechanical properties and to a reduction of the depth of carbonation. The new hydrophobic nanocomposite product is therefore a promising material for the protection and consolidation of gypsum monuments and artifacts of cultural interest.
Modeling and optimization of an M/M/1/K/WV retrial queue with dual-phase service, customer's balking under F-policy
Authors: Singh Sanga Sudeep , Vankudothu Ramesh
Published: September 2024

This paper examines an M/M/1/K/W V queue, incorporating features such as retrial queue, working
vacation (WV), admission control F -policy, customer balking, and dual-phase service. Upon arrival,
customers observing an extended queue length have the option to refrain from joining the queue, a
phenomenon known as balking. Alternatively, if a customer decides to join the queue but finds the
service facility occupied, they are directed to a virtual space termed the retrial orbit. After a random
duration, customers in the retrial orbit make subsequent attempts to avail the service. In our study,
dissatisfied customers with the initial phase of service have the option to choose a secondary phase of
service. The F -policy adeptly regulates customer congestion by limiting admissions when the system
capacity is reached and resuming admissions once the capacity decreases to a predefined threshold value
F. Introducing the working vacation concept in our study ensures continuous service provision during the
vacation period, albeit at a reduced rate compared to the standard operational pace. This multifaceted
approach contributes to a more nuanced and flexible management of customer influx in the system.
The model is mathematically formulated by developing steady-state difference equations, which are then
solved using the matrix analytical method. Diverse system metrics are subsequently derived, providing
valuable insights for system managers to effectively analyze and navigate the queueing management and
decision-making processes. We also present a numerical example to illustrate the impact and behavior
of input parameters on a range of system metrics. Furthermore, we employ the adaptive neuro-fuzzy
inference system (ANFIS) to validate our analytical findings against the ANFIS results. Establishing a
bivariate cost function is a noteworthy aspect of our research, and we minimize cost function using both
the quasi-Newton method (QNM) and genetic algorithm (GA), enhancing the robustness and reliability
of our optimization approach. The practical justification of the model is demonstrated in an automotive
service facility (ASF) where malfunctioning bikes (MBs) arrive for servicing.
Cycling Intensity Effect on Running Plus Cycling Performance among
Triathletes
Authors: Vivan Lavínia , dos Anjos Vinicius Ribeiro , Engelke Paulo , de Lira Claudio Andre Barbosa , Vancini Rodrigo Luiz , Weiss Katja , Knechtle Beat , Andrade Marília Santos
Published: September 2024

Running performance is crucial for triathlon performance. However, the prior bout
of cycling may affect the running split time. This study compared the
triathletes’ cycling plus running (C+R) time, when cycling was performed at
three different intensities and running was maximal. A total of 38 athletes (21
males and 17 females) were included. Body composition, maximal oxygen uptake,
and functional threshold power (FTP) was evaluated. The participants visited the
laboratory three times to cycle 20 km at 80%, 85%, or 90% FTP (in randomized
order) and run 5 km as fast as possible. Males ran faster after cycling at 80%
FTP than after cycling at 90% FTP (mean difference=35.1 s; CI% 2.2, 68.1 s;
p=0.035). The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean
difference=57.7 s; CI% 26.1, 89.3 s; p<0.001). For females, no significant
difference was observed in the running time after cycling at 80%, 85%, or 90%
FTP. The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean
difference=80.9 s; CI% 29.7, 132.1 s; p=0.002). In conclusion, to optimize
triathlon performance, male and female athletes should cycle at a minimum of 90%
FTP.
Affordable Care Act Medicaid expansion, access to health care, and financial behavior of the United States adults
Authors: Bin Abdul Baten Redwan , Noman Abdullah , Rahman Mohammad Nakibur
Published: September 2024

The access to care benefits of Affordable Care Act (ACA) Medicaid expansions are important for 45–64-year-old adults who are living below 100% of the Federal Poverty Level, a particularly vulnerable group in the United States (US). Gaining coverage from Medicaid expansions should improve access to healthcare and affect social determinants of health, including financial behavior. We analyzed data from 2009 to 2018 from the National Financial Capability Survey (NFCS) and utilize a difference-in-differences model to compare outcomes changes in states with and without expansion before and after the ACA Medicaid expansions. Overall, Medicaid expansion was associated with increased healthcare access for 45–64-year-olds, potentially resulting in better healthcare experience. Results indicate effects of the Medicaid expansion on the financial behavior of 45–64-year-olds, with evidence of credit card bills being paid in full, higher banking activities, and better financial preparedness. These findings have important implications for financial regulators and healthcare policymakers.
Home Team Effect and Opinion Network after the Sewol Ferry Disaster: A mixed-method study of the influence of symbol and feedback on liberal versus conservative newspapers’ negative opinions
Authors: Cho Ki Woong
Published: September 2024

Studies on the symbol and feedback effects on the opinion based on the theory are lacking. Acknowledging that the media express their stance and opinion and that negative opinions are critical to policy change, this paper fills the gap in the literature by illustrating and comparing the effects of emotional and cognitive symbols and positive and negative feedback on the liberal and conservative newspapers’ negative opinions of South Korean President Park Geun-hye’s administration (Park administration) after the Sewol Ferry sank. This study used qualitative and quantitative methods to analyze the archival data, including 424 newspaper editorials and economic data published from April to December 2014. Multiple regression analyses were conducted following a content analysis of newspaper editorials, and network analysis was used to analyze the data. The results mostly supported the hypotheses that symbols and feedback affect the negative opinion on the political discourse, with new findings that deviate from the existing theories. The emotional symbols exerted a stronger influence on the negative opinion compared to cognitive symbols, regardless of the newspaper’s stance. The political system’s response to the positive and negative feedback was not definite; instead, it varied depending on the situation and newspaper perspective. The liberal newspaper responded to symbols and feedback more sensitively compared to the conservative one under the conservative administration. The conservative newspaper expressed more lenient negative opinions towards the conservative administration than the liberal newspaper, supporting the home team effect. These findings have practical and theoretical implications for future studies, highlighting the application of opinion networks in social science.
Charge dynamics in the 2D/3D semiconductor heterostructure WSe2/GaAs
Authors: Rojas-Lopez Rafael R. , Hendriks Freddie , van der Wal Caspar H. , Guimarães Paulo S. S. , Guimarães Marcos H. D.
Published: September 2024

Understanding the relaxation and recombination processes of excited states in two-dimensional (2D)/three-dimensional (3D) semiconductor heterojunctions is essential for developing efficient optical and (opto)electronic devices, which integrate van der Waals 2D materials with more conventional 3D ones. In this work, we unveil the carrier dynamics and charge transfer in a monolayer of WSe2 on a GaAs substrate. We use time-resolved differential reflectivity to study the charge relaxation processes involved in the junction and how they change when compared to an electrically decoupled heterostructure, WSe2/hBN/GaAs. We observe that the monolayer in direct contact with the GaAs substrate presents longer optically excited carrier lifetimes (3.5 ns) when compared with the hBN-isolated region (1 ns), consistent with a strong reduction of radiative decay and a fast charge transfer of a single polarity. Through low-temperature measurements, we find evidence of a type-II band alignment for this heterostructure with an exciton dissociation that accumulates electrons in GaAs and holes in WSe2. The type-II band alignment and fast photoexcited carrier dissociation shown here indicate that WSe2/GaAs is a promising junction for advanced photovoltaic and other optoelectronic devices, making use of the best properties of van der Waals (2D) and conventional (3D) semiconductors.
Photonic crystal enhanced light emitting diodes fabricated by single pulse laser interference lithography
Authors: Lin Zhiheng , Wang Yaoxun , Wang Yun-Ran , Han Im Sik , Hopkinson Mark
Published: September 2024

Integration of photonic crystal (PhC) configurations onto the surfaces of light-emitting diodes (LEDs) can play an important role in enhancing light extraction efficiency. While the literature is rich with various PhC fabrication approaches, there is a need for high throughput methods that are appropriate for low-cost devices. In this paper, we report the use of single pulse laser interference lithography (LIL) for the fabrication of photonic crystal structures on LEDs. The use of brief nanosecond pulse exposures offers significant benefits for high-throughput production. In our study, we have applied single pulse LIL on GaAs/AlGaAs LED structures to achieve high-quality photoresist arrays and then have used inductively coupled plasma etching to create nanoholes into the epitaxial structure. The resulting array forms an effective PhC, controlling surface transmission. Electroluminescence (EL) analyses confirm that these structures enhance the average EL intensity of the LED by up to 3.5 times at room temperature. This empirical evidence underscores the efficacy and potential of this fabrication approach in advancing the functional capabilities of semiconductor-based light-emitting devices.
Microfluidic supercritical CO2 applications: Solvent extraction, nanoparticle synthesis, and chemical reaction
Authors: Yang Junyi , Tsai Peichun Amy
Published: September 2024

Supercritical CO2, known for its non-toxic, non-flammable and abundant properties, is well-perceived as a green alternative to hazardous organic solvents. It has attracted considerable interest in food, pharmaceuticals, chromatography, and catalysis fields. When supercritical CO2 is integrated into microfluidic systems, it offers several advantages compared to conventional macro-scale supercritical reactors. These include optical transparency, small volume, rapid reaction, and precise manipulation of fluids, making microfluidics a versatile tool for process optimization and fundamental studies of extraction and reaction kinetics in supercritical CO2 applications. Moreover, the small length scale of microfluidics allows for the production of uniform nanoparticles with reduced particle size, beneficial for nanomaterial synthesis. In this perspective, we review microfluidic investigations involving supercritical CO2, with a particular focus on three primary applications, namely, solvent extraction, nanoparticle synthesis, and chemical reactions. We provide a summary of the experimental innovations, key mechanisms, and principle findings from these microfluidic studies, aiming to spark further interest. Finally, we conclude this review with some discussion on the future perspectives in this field.
The effects of Gurney flap on the aerodynamic characteristics of two airfoils in non-continuum regimes
Authors: Jiang Dingwu , Li Jin , Li Haomin , Wan Zhao , Wang Xinguang , Mao Meiliang
Published: September 2024

Gurney flap is a simple and effective high-lift device that has the potential to reduce the takeoff-and-landing distance for transport aircraft. It is also a good option for enhancing the airfoil cruising characteristics. However, its effectiveness in non-continuum regimes has rarely been studied. The Unified Gas Kinetic Scheme algorithm, which is valid for all flow regimes, is further developed and used to simulate the flow field around a cambered airfoil and a high-speed quadrilateral airfoil with and without the Gurney flap in the supersonic non-continuum flow regimes. The distribution function shapes at different spatial locations are provided and analyzed. The effects of angle of attack, free-stream Knudsen number, free-stream Mach number, Gurney flap height, and Gurney flap mounting angle on the aerodynamic characteristics of the two airfoils are studied. The results show that the lift and drag of the airfoil with the attached Gurney flap are increased. The pressure rise on the lower surface of the airfoil is the primary factor contributing to the increase in lift. The overall increase in drag mainly comes from the Gurney flap, which also generates a small amount of negative lift. When the angle of attack is less than the critical angle of attack, the Gurney flap can increase the lift-to-drag ratio of the airfoil and improve its aerodynamic performance. The critical angle of attack decreases with the increase in the free-stream Knudsen number and the free-stream Mach number. It decreases with increasing Gurney flap height and increases with increasing Gurney flap mounting angle.
Reconstructive metal–semiconductor phase transition between nonlayered and layered tungsten dinitride
Authors: Tang Xiaoting , Wang Shijie , Zhou Jun , Burton Lee A. , Feng Yuanping , Liu Yi
Published: September 2024

Reconstructive phase transitions are characterized by significant changes in the crystal structure of a material, typically accompanied by dramatic changes in its physical properties. In this Letter, via first-principles calculations, we report a reconstructive phase transition between nonlayered and layered tungsten dinitride (WN2) with kinetic energy barriers of 0.19 and 0.61 eV per formula unit depending on the transition direction. The nonlayered-to-layered transition can be triggered when an in-plane biaxial strain reaches 9.3%, while the layered-to-nonlayered transition happens at 53.5% of an out-of-plane uniaxial strain. The nonlayered and layered WN2 phases exhibit distinct structural, bonding, and electronic characteristics. Another intrinsic advantage of the reconstructive transition between layered and nonlayered phases is that it can be easily extended to two-dimensional (2D) nanoscale regions. Our results predict a rich phase diagram for 2D WN2 under strains, appealing for advanced nanoelectronics applications such as phase-change electronics or pressure sensors.
Numerical investigation of vehicle water entry with angle of attack
Authors: Sun Yueyang , Zhang Xingyu , Wang Xu , Fan Xudong , Wang Wenhui , Lyu Xujian
Published: September 2024

This paper investigates the water entry of a vehicle with angle of attack (AOA) through numerical methods, employing the volume-of-fluid multiphase flow model and overset grid technique. The validity of the numerical model is confirmed through experimental verification. Building upon this, the study analyzes the motion characteristics, cavity evolution, and flow field distribution of the vehicle during water entry, considering the influence of AOA and falling velocity. Numerical findings indicate that the collapse of the right side of the cavity induces a transient lateral force on the vehicle, resulting in vehicle tilting. Moreover, an increase in initial velocity delays vehicle tilt, while an increase in AOA reduces vehicle motion stability, leading to earlier tilting. Initially, the vehicle rotates counterclockwise around the Oz axis of the projectile coordinate system. Subsequent to cavity collapse, the vehicle experiences an opposing moment, leading to a reduction in rotation speed and eventual rotation in the opposite direction. Water impact triggers sudden changes in the vehicle's lift and drag coefficients, while cavity sticking induces a minor abrupt change in the lift coefficient. Following cavity collapse, both lift and drag coefficients exhibit significant oscillations. Unlike typical cavity collapse phenomena, the flow field on the right side of the vehicle undergoes alternating high-pressure and low-pressure regions.
Vascularized platforms for investigating cell communication via extracellular vesicles
Authors: Kim Junyoung , Ro Jooyoung , Cho Yoon-Kyoung
Published: September 2024

The vascular network plays an essential role in the maintenance of all organs in the body via the regulated delivery of oxygen and nutrients, as well as tissue communication via the transfer of various biological signaling molecules. It also serves as a route for drug administration and affects pharmacokinetics. Due to this importance, engineers have sought to create physiologically relevant and reproducible vascular systems in tissue, considering cell–cell and extracellular matrix interaction with structural and physical conditions in the microenvironment. Extracellular vesicles (EVs) have recently emerged as important carriers for transferring proteins and genetic material between cells and organs, as well as for drug delivery. Vascularized platforms can be an ideal system for studying interactions between blood vessels and EVs, which are crucial for understanding EV-mediated substance transfer in various biological situations. This review summarizes recent advances in vascularized platforms, standard and microfluidic-based techniques for EV isolation and characterization, and studies of EVs in vascularized platforms. It provides insights into EV-related (patho)physiological regulations and facilitates the development of EV-based therapeutics.
Origin of the vibrational structure of the first absorption band of cis/trans isomeric 1,6-diphenylhexatrienes by (TD)DFT calculations
Authors: Martin-Somer Ana , Catalán Javier
Published: September 2024

We present a detailed spectroscopic analysis of the first absorption band of the six possible conformers of 1,6-diphenyl-1,3,5-hexatriene, obtained by changing the configuration of trans double bonds to cis. To this end, we computed the absorption spectra using FCclasses 3.0 code. First, we assessed the performance of PBE0 and CAM-B3LYP density functional theory functionals with different basis sets to reproduce the experimental spectra. Additionally, we considered different models to compute the spectra. PBE0/def2tZVP with an adiabatic hessian model with internal coordinates yields results in very good agreement with experimental data. Subsequently, we analyzed the different contributions of vibronic transition to the spectral structure, correlating ground state conformation with spectral shape, and studied the effect of temperature on the absorption first band.
Bayesian-inverted laser Thomson scattering measurements indicate electrostatic erosion pathways in magnetically-shielded Hall effect thrusters
Authors: Suazo Betancourt Jean Luis , Lopez-Uricoechea Julian , Butler-Craig Naia , Steinberg Adam M. , Walker Mitchell L. R.
Published: September 2024

Magnetically shielded Hall effect thrusters suffer from pole erosion as their life-limiting mechanism. However, the dominant physical mechanism causing this erosion remains unclear, limiting the ability create designs that mitigate erosion and the predictive accuracy of simulations used to aid in design. This paper provides spatially resolved laser Thomson scattering measurements of electron temperature and density in the near field plume of a magnetically shielded Hall effect thruster, traversing the front pole region from the discharge channel centerline to the cathode centerline. The signals are inverted in a Bayesian framework, and the data are compared qualitatively and quantitatively to simulations of the same Hall effect thruster. Based on the electron momentum equation, electron pressure gradient is used as a proxy for the electron-predicted electrostatic potential gradient. To within the accuracy of this approximation, the electron pressure has a minimum immediately in front of the front pole. Hence, ions have an electrostatic potential avenue from the discharge region to the front pole, validating this mechanism of pole erosion.
Integrated modeling of anisotropic neutron yields of classical and spherical tokamaks
Authors: Goncharov P. R.
Published: September 2024

Estimations of counting rates of neutron spectrometers in experiments on controlled fusion with magnetic confinement, as well as calculations of energy resolved flux densities of fusion neutrons from plasma to the walls of a reactor require spatial integration of the local, usually anisotropic function of the neutron source. The integrated modeling consists of three main stages. First, sources of fast particles in beam- or wave-heated plasma are calculated. The next stage deals with spatial, energetic, and angular velocity distributions of plasma ions. Finally, double differential rate coefficients of nuclear fusion reactions are computed. This article describes calculations of spatial distributions of nuclear fusion reaction rates in classical and spherical tokamaks and the anisotropy of the neutron yield and spectra. The results are based on analytical formulas for energetic and angular distributions of the local source of fusion products in plasma. Examples of energetic spectral densities of neutron fluxes on first walls are presented, as well as energy resolved counting rates of collimated neutron spectrometers for perpendicular and tangential lines of sight.
Depth profiling of temperature in water at a micrometer scale using time resolved Brillouin scattering
Authors: Maslah Zouhir , Audoin Bertrand
Published: September 2024

Picosecond ultrasonics is a technique where coherent acoustic phonons are generated with frequencies in the GHz frequency range. When optical detection is operated in a transparent medium, the interaction of these phonons with the probe pulses yields oscillations in the time domain that reveal Brillouin scattering. Their frequency is at the Brillouin frequency shift, commensurate with the phonon velocity. As the pump–probe experiments are time-resolved, changes in the Brillouin frequency with time can be attributed to changes in sound velocity with depth. As sound velocity is temperature-dependent in liquids, we show that the picosecond ultrasonics technique can be used for temperature depth profiling in liquids. In this work, the concept is proved using the pump absorption itself as a heat source and confronting measured changes in Brillouin frequency with depth with data resulting from the derivation of a 3D modeling of the temperature rise in the liquid. We demonstrate the remote depth profiling of temperature, with measured data spaced at a distance less than the optical wavelength.
Scintillation of colloidal nanocrystals
Authors: Diroll B. T. , Guzelturk B.
Published: September 2024

Scintillators are materials that convert ionizing radiation in the form of particles or photons into low-energy photons in the ultraviolet to near-infrared spectral range. This work reviews efforts to use colloidal nanocrystals as scintillator materials. To date, research on colloidal nanocrystals as scintillators has focused on doped phosphor systems, quantum dots and related structures, and perovskite-based nanocrystals. Among various material classes and forms, colloidal semiconductor nanocrystals stand out thanks to their appealing fluorescence properties, yet understanding of their radioluminescence and cathodoluminescence is incomplete. This review discusses fundamental limits and material design challenges toward achieving high brightness, fast speed, and durable scintillator performance with nanocrystal scintillators. First, this review describes the basic principles and efficiency limitations of scintillation, particularly the large influence of multiple exciton generation in many nanocrystal species, as well as performance metrics. Second, methods for measurement are described. Third, we review the results of the main classes of nanocrystal scintillators, including quantum dots and related particles, perovskites, and doped-phosphor particles. Fourth, scintillation imaging is discussed in terms of the relevant performance metrics and results obtained using nanocrystal materials. Finally, we note the strengths and weaknesses of nanocrystal scintillators and discuss potential areas of further development.
Electrical properties and evaluation of band tail states in Mg doped p-type multilayer hBN
Authors: Marye Shambel Abate , Kumar Ravi Ranjan , Thao Le Thi Phuong , Chung Chin-Han , Tumilty Niall
Published: September 2024

A series of Mg doped p-type multi-layered hBN films were prepared by atmospheric pressure chemical vapor deposition. Temperature dependent conductivity measurements were performed from 0.1 Hz to 10 MHz to analyze the characteristics of tail states close to the valence band edge. Jonscher's power law (Aωs) is successfully applied to understand charge carrier transport through these states. In this work, exponent S increases from 0.6 → 0.8, 0.8 → 0.995, and 1.4 → 1.6 for samples B (precursor temperature, 750 °C), D (850 °C), and E (900 °C), indicating that non-overlapping small polaron tunneling dominates to 548 K. Polaron binding energies of 0.2–0.40 eV and tunneling distances <4.9 Å are calculated, confirming transport through localized states. The density of states near the Fermi level N(EF) was extracted from a fit to the AC conductivity data, yielding values of 1015 and 1017eV−1cm−3 as the precursor temperature increases. Singular Mg acceptor levels of 74, 30, and 17 meV are identified for each sample. A hole concentration from 6.5 × 1017 to 1 × 1018 cm−3 and carrier mobility from 18 to 25 cm2/V s is measured at 300 K. From RC fitting, carrier recombination lifetimes of 1.2, 0.4, and 0.35 μs are determined. Fermi's golden rule is used to determine an optical joint density of states of 1.1 × 1021 eV−1 cm−3 at a band edge. Overall, we show that AC conductivity is an effective method to evaluate midgap states in 2D (two-dimensional) materials at EF and p-type hBN possesses sufficient electrical properties to be integrated into a wide range of semiconductor applications.
Self-stabilized true random number generator based on spin–orbit torque magnetic tunnel junctions without calibration
Authors: Xu Y. Q. , Li X. H. , Zhang R. , Wan C. H. , Wang Y. Z. , Liu S. Q. , Luo X. M. , Lan G. B. , Xia J. H. , Yu G. Q. , Han X. F.
Published: September 2024

Magnetic tunnel junction (MTJ)-based true random number generators (TRNG), which are promisingly utilized as hardware accelerators for probabilistic computing, may suffer intrinsic performance drifting and fluctuation in the probability space and performance variations in device arrays. In order to preventively avoid these concerns, it is necessary to develop strategies that can help MTJ-based TRNG to be self-stabilized and calibration-free. Here, we derived a simple and easily handleable strategy that only depends on the current sampled state of an MTJ device without any historical or statistic information or a pre-calibrated probabilistic switching property to dynamically tune its sampling probability for the next sampling operation. In this way, the long-term sampling probability of the MTJ can be proved to automatically converge into a desired probability with little fluctuation and drifting. We further experimentally demonstrate such a self-stabilized MTJ-based TRNG. Our results show that the TRNG can generate binary random numbers with any destined probability regardless of its initial state. Furthermore, the TRNG also displays the desired capability of excellently hedging against performance drifting and fluctuations. All these combined allow the self-stabilized TRNG without calibration to be more viable for high-quality entropy source applications.
Physics-informed quantum neural network for solving forward and inverse problems of partial differential equations
Authors: Xiao Y. , Yang L. M. , Shu C. , Chew S. C. , Khoo B. C. , Cui Y. D. , Liu Y. Y.
Published: September 2024

Recently, physics-informed neural networks (PINNs) have aroused an upsurge in the field of scientific computing including solving partial differential equations (PDEs), which convert the task of solving PDEs into an optimization challenge by adopting governing equations and definite conditions or observation data as loss functions. Essentially, the underlying logic of PINNs is based on the universal approximation and differentiability properties of classical neural networks (NNs). Recent research has revealed that quantum neural networks (QNNs), known as parameterized quantum circuits, also exhibit universal approximation and differentiability properties. This observation naturally suggests the application of PINNs to QNNs. In this work, we introduce a physics-informed quantum neural network (PI-QNN) by employing the QNN as the function approximator for solving forward and inverse problems of PDEs. The performance of the proposed PI-QNN is evaluated by various forward and inverse PDE problems. Numerical results indicate that PI-QNN demonstrates superior convergence over PINN when solving PDEs with exact solutions that are strongly correlated with trigonometric functions. Moreover, its accuracy surpasses that of PINN by two to three orders of magnitude, while requiring fewer trainable parameters. However, the computational time of PI-QNN exceeds that of PINN due to its operation on classical computers. This limitation may improve with the advent of commercial quantum computers in the future. Furthermore, we briefly investigate the impact of network architecture on PI-QNN performance by examining two different QNN architectures. The results suggest that increasing the number of trainable network layers can enhance the expressiveness of PI-QNN. However, an excessive number of data encoding layers significantly increases computational time, rendering the marginal gains in performance insufficient to compensate for the shortcomings in computational efficiency.
Tilted-chiral-state-induced topological Hall effect in chiral magnetic soliton host Cr1/3TaS2
Authors: Du Zan , Liu Wei , Wang Aina , Rahman Azizur , Han Yuyan , Tong Wei , Fan Jiyu , Ma Chunlan , Ge Min , Pi Li , Zhang Yuheng , Qu Zhe , Zhang Lei
Published: September 2024

Chromium-intercalated Cr1/3TaS2 is well known for hosting a nontrivial chiral magnetic soliton lattice (CSL) with the reported highest Curie temperature (TC∼151 K) and strongest spin–orbit coupling, which has significant applications in gigahertz and high-speed spintronic devices. Herein, we thoroughly investigate the magneto-electrical transport properties of Cr1/3TaS2 single crystals. For H//ab, our magnetoresistance (MR) measurements reveal distinctive step-like behaviors, which are attributed to the formation and annihilation of chiral magnetic solitons. When under an oblique field, similar but weaker MR behaviors are observed compared to H//ab, indicating the appearance of an inclination-field-induced tilted-CSL. A topological Hall effect is observed under an oblique field, which is suggested to be induced by a nonzero topological charge density resulting from the tilted chiral states. The Cr1/3TaS2 offers an intriguing platform for studying the impact of chiral magnetic structures on magneto-electrical properties, which holds promise for both future spintronic device applications and fundamental investigation.
On particle-modified velocity fields of particulate Taylor–Couette flow
Authors: Ru C. Q.
Published: September 2024

Particulate Taylor–Couette flow of a particle-laden viscous fluid between two coaxial rotating cylinders is studied using a novel hydrodynamic model. With the volume fraction of particles as the dimensionless small parameter, explicit leading-order solutions are derived for the general case of dispersed particles heavier or lighter than the carrier fluid. It is shown that, unlike the classical azimuthal velocity field of a clear fluid without particles, dispersed particles generally have a radial velocity toward the outer or inner cylinder depending on the angular velocities and radii of the two cylinders and whether the particles are heavier or lighter than the carrier fluid, in qualitative agreement with some known results reported in literature on heavier or lighter particles, respectively. In some cases, such as the flow driven by rotating inner cylinder with a wider gap between the two cylinders and a moderate value of Stokes number of particles, our results predict the existence of a circular ring between two cylinders, which attracts or repels heavier or lighter particles that could have relevant physical implications. Beyond existing literature on the Taylor–Couette flow with neutrally buoyant particles, these results could offer new insight and useful explicit solutions to the Taylor–Couette flow with particles heavier or lighter than the carrier fluid.
Experimental analysis of particle dynamics influenced by cavitation bubbles near a rigid wall
Authors: Shen Xiaobo , Han Wei , Li Rennian , Yang Shiqi , Nan Haozhi , Bai Lu , Dong Yifan , Meng Qingduo
Published: September 2024

This study utilized experimental methods involving high-speed cameras to observe the interaction between cavitation bubbles, generated by a low-voltage electric spark device, and particles near a rigid wall. The dynamic characteristics of the particles were analyzed under varying conditions, including different cavitation bubble sizes, particle sizes, and distances between the cavitation bubble and the wall. Two characteristic parameters were introduced: χ for the particle and cavitation bubble sizes, and λ for the cavitation bubble wall distance. Qualitative distinctions were made among types of particle–bubble interactions, and force analysis was conducted under conditions where χ exceeded the threshold χt. The findings reveal that when χ < χt, particle motion is primarily influenced by the jet effects produced by the cavitation bubble. Conversely, when χ > χt, particle motion is dominated by the radiation forces exerted by the cavitation bubble. Under jet-dominated conditions, particle trajectories were observed to be erratic and unpredictable. For cases where λ < 0, the high-speed jet directly impacts the particle. Conversely, for λ > 0, the jet's velocity decays rapidly upon reaching the particle. In scenarios dominated by radiation forces, the cavitation bubble drew particles away from the wall, followed by their free fall back toward it. The influence of gravity, buoyancy, bubble radiation force, fluid resistance, and virtual mass force on particles was studied when radiation forces prevailed. The acceleration formula for particles was derived through the application of the bubble dynamics equation and was refined based on experimental observations.
Jump discontinuities of finite-basis-set exchange–correlation potentials at atomic nuclei
Authors: Moore Conrad C. , Staroverov Viktor N.
Published: September 2024

The kinetic energy density of electrons and the gradient of the electron density have pronounced jump discontinuities at the positions of the atomic nuclei in molecules. Certain exact relations then imply that molecular Kohn–Sham exchange–correlation potentials may also be discontinuous at atomic nuclei. Here, we confirm that exchange–correlation potentials derived from Hartree–Fock and correlated wavefunctions within Slater-type basis sets do exhibit such discontinuities. Despite their persistence even in large basis sets, these discontinuities are almost certainly artifacts of basis set finiteness and are expected to disappear in the basis-set limit. The findings imply that imposing electron–nucleus cusp conditions in spherically averaged form may not always be appropriate.
High-performance β-Ga2O3 Schottky barrier diodes with Mg current blocking layer using spin-on-glass technique
Authors: Li MuJun , He MingHao , Wang XiaoHui , Jiang Yang , Wen KangYao , Du FangZhou , Deng ChenKai , He JiaQi , Zhang Yi , Yu WenYue , Wang Qing , Yu HongYu
Published: September 2024

This study presents a β-Ga2O3 Schottky barrier diode (SBD) with a Mg current blocking layer (Mg-CBL) fabricated via the Mg-doped spin-on-glass (Mg-SOG) technique, affording a surface roughness damage-free thermal doping process. The proposed technique improves the breakdown voltage (BV) of the β-Ga2O3 SBD from 580 to 2200 V and marginally increases the specific on-resistance from 4.0 to 4.8 mΩ cm2, yielding a notable power figure of merit exceeding 1 GW/cm2. The Mg-CBL effectively captures the electrons and mitigates the electric field, leading to a significant increase in BV and slight decrease in the forward current loss. The temperature-dependent I–V curves reveal that the reverse saturation current decreases owing to the physical mechanism of the Mg-CBL structure. Moreover, the Gaussian distribution model is applied to correct the Schottky barrier inhomogeneity stemming from the Mg-CBL. The results illustrate the promising potential of the Mg-CBL fabricated via the Mg-SOG technique for yielding high-performance β-Ga2O3 SBDs.
Magnetic resonance of spin current and its accompanying heating or cooling
Authors: Tang Yuxin , Zhang Lin , Jiang Feng , Yan Yonghong , Zhu Yanyan
Published: September 2024

Motivated by the booming development of spintronics based on quantum dot systems, we employed the standard nonequilibrium Green’s function theory to derive the transport formula and the heat generation formula of a quantum dot coupled to a substrate and study the relation between spin current and its accompanying heating or cooling. Our results demonstrate that (i) a thermal bias combined with Zeeman splitting can generate steady spin current in a limited dot level range, while a rotating magnetic field can generate time-average spin current in a global range and pure spin current can induce more heat generation than non-pure spin current; (ii) magnetic resonance of spin current can also effectively enhance heat generation; (iii) appropriate environmental temperature in conjunction with a thermal bias makes cooling, while increasing the frequency of the rotating magnetic can easily give rise to the transition from cooling to heating; and (iv) enhancing the coupling between quantum dots and substrates can effectively reduce heat generation while maintaining the fundamental properties of pure spin current.
Unsteadiness in vacuum ejector and their sources
Authors: Raju Martin , Desikan S. L. N. , Vaidyanathan Aravind
Published: September 2024

This study investigates unsteadiness in the secondary chambers of a vacuum ejector during its transient startup phase. Experiments reveal unsteadiness at various frequencies across different nozzle pressure ratios. These frequencies are categorized as symmetric (in-phase) or asymmetric (counter-phase) through cross-spectral phase analysis. Dynamic mode decomposition, using time-resolved schlieren images, elucidates the corresponding flow structures and acoustic fields. The mode shapes display alternating density gradients along both the longitudinal and lateral axes, which explain the oscillatory behavior of the jet. These oscillations arise from instabilities in the jet's shear layer and acoustic disturbances due to the jet being confined within a duct. Using empirical relations, spectrogram analysis, time-resolved schlieren imaging, and classical wave theory, the sources of unsteadiness in the secondary chamber are identified as jet screech, its harmonics, and modes due to duct acoustics (symmetric and asymmetric). Additionally, the screech feedback loop in the vacuum ejector is found to be distinct from that in open jets, and the effect of screech on duct-mode acoustics is also observed.
Enhanced metamorphic CO
2
release on the Proterozoic Earth
Authors: Stewart E. M. , Penman Donald E.
Published: September 2024

Rock metamorphism releases substantial CO
2
over geologic timescales (>1 My), potentially driving long-term planetary climate trends. The nature of carbonate sediments and crustal thermal regimes exert a strong control on the efficiency of metamorphic CO
2
release; thus, it is likely that metamorphic CO
2
degassing has not been constant throughout time. The Proterozoic Earth was characterized by a high proportion of dolomite-bearing mixed carbonate-silicate rocks and hotter crustal regimes, both of which would be expected to enhance metamorphic decarbonation. Thermodynamic phase equilibria modeling predicts that the metamorphic carbon flux was likely ~1.7 times greater in the Mesoproterozoic Era compared to the modern Earth. Analytical and numerical approaches (the carbon cycle model PreCOSCIOUS) are used to estimate the impact this would have on Proterozoic carbon cycling and global atmospheric compositions. This enhanced metamorphic CO
2
release alone could increase pCO
2
by a factor of four or more when compared to modern degassing rates, contributing to a stronger greenhouse effect and warmer global temperatures during the expansion of life on the early Earth.
Nr2f1
enhancers have distinct functions in controlling
Nr2f1
expression during cortical development
Authors: Liu Zhidong , Ypsilanti Athéna R. , Markenscoff-Papadimitriou Eirene , Dickel Diane E. , Sanders Stephan J. , Dong Shan , Pennacchio Len A. , Visel Axel , Rubenstein John L.
Published: September 2024

There is evidence that transcription factor (TF) encoding genes, which temporally control development in multiple cell types, can have tens of enhancers that regulate their expression. The NR2F1 TF developmentally promotes caudal and ventral cortical regional fates. Here, we epigenomically compared the activity of
Nr2f1’s
enhancers during mouse cortical development with their activity in a transgenic assay. We identified at least six that are likely to be important in prenatal cortical development, with three harboring de novo mutants identified in ASD individuals. We chose to study the function of two of the most robust enhancers by deleting them singly or together. We found that they have distinct and overlapping functions in driving
Nr2f1’s
regional and laminar expression in the developing cortex. Thus, these two enhancers, probably in combination with the others that we defined epigenetically, precisely tune
Nr2f1’s
regional, cell type, and temporal expression during corticogenesis.
Investigating the
cis-
regulatory basis of C
3
and C
4
photosynthesis in grasses at single-cell resolution
Authors: Mendieta John Pablo , Tu Xiaoyu , Jiang Daiquan , Yan Haidong , Zhang Xuan , Marand Alexandre P. , Zhong Silin , Schmitz Robert J.
Published: September 2024

While considerable knowledge exists about the enzymes pivotal for C
4
photosynthesis, much less is known about the
cis-
regulation important for specifying their expression in distinct cell types. Here, we use single-cell-indexed ATAC-seq to identify cell-type-specific accessible chromatin regions (ACRs) associated with C
4
enzymes for five different grass species. This study spans four C
4
species, covering three distinct photosynthetic subtypes:
Zea mays
and
Sorghum bicolor
(NADP-dependent malic enzyme),
Panicum miliaceum
(NAD-dependent malic enzyme),
Urochloa fusca
(phosphoenolpyruvate carboxykinase), along with the C
3
outgroup
Oryza sativa
. We studied the
cis-
regulatory landscape of enzymes essential across all C
4
species and those unique to C
4
subtypes, measuring cell-type-specific biases for C
4
enzymes using chromatin accessibility data. Integrating these data with phylogenetics revealed diverse co-option of gene family members between species, showcasing the various paths of C
4
evolution. Besides promoter proximal ACRs, we found that, on average, C
4
genes have two to three distal cell-type-specific ACRs, highlighting the complexity and divergent nature of C
4
evolution. Examining the evolutionary history of these cell-type-specific ACRs revealed a spectrum of conserved and novel ACRs, even among closely related species, indicating ongoing evolution of
cis
-regulation at these C
4
loci. This study illuminates the dynamic and complex nature of
cis
-regulatory elements evolution in C
4
photosynthesis, particularly highlighting the intricate
cis-
regulatory evolution of key loci. Our findings offer a valuable resource for future investigations, potentially aiding in the optimization of C
3
crop performance under changing climatic conditions.
Alveolar macrophage function is impaired following inhalation of berry e-cigarette vapor
Authors: Kulle Amelia , Li Ziyi , Kwak Ashley , Mancini Mathieu , Young Daniel , Avizonis Daina Zofija , Groleau Marc , Baglole Carolyn J. , Behr Marcel A. , King Irah L. , Divangahi Maziar , Langlais David , Wang Jing , Blagih Julianna , Penz Erika , Dufour Antoine , Thanabalasuriar Ajitha
Published: September 2024

In the lower respiratory tract, the alveolar spaces are divided from the bloodstream and the external environment by only a few microns of interstitial tissue. Alveolar macrophages (AMs) defend this delicate mucosal surface from invading infections by regularly patrolling the site. AMs have three behavior modalities to achieve this goal: extending cell protrusions to probe and sample surrounding areas, squeezing the whole cell body between alveoli, and patrolling by moving the cell body around each alveolus. In this study, we found Rho GTPase, cell division control protein 42 (CDC42) expression significantly decreased after berry-flavored e-cigarette (e-cig) exposure. This shifted AM behavior from squeezing to probing. Changes in AM behavior led to a reduction in the clearance of inhaled bacteria,
Pseudomonas aeruginosa
. These findings shed light on pathways involved in AM migration and highlight the harmful impact of e-cig vaping on AM function.
Introduction
Authors: Fiorentini Ilaria , Zanchi Chiara
Published: September 2024

The relationship between ambiguity and vagueness is traditionally
considered rather complex. It is not always easy to distinguish between the
two phenomena, and the two concepts may seem to overlap. This introduction
aims to clarify what is generally understood by ambiguity and vagueness in
previous scholarship and to emphasize the purpose of the volume, also in
relation to the questions that remain open about the two phenomena. In
presenting the chapters that make up the volume, an overview is given of how
each of them responds to these questions. Finally, an attempt is made to
draw some conclusions about the novel aspects brought about by the volume
and possible future developments.