bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerating QM/MM simulations of electrochemical interfaces through machine learning of electronic charge densities
Authors: Grisafi Andrea , Salanne Mathieu 
Published: July 2024

A crucial aspect in the simulation of electrochemical interfaces consists in treating the distribution of electronic charge of electrode materials that are put in contact with an electrolyte solution. Recently, it has been shown how a machine-learning method that specifically targets the electronic charge density, also known as SALTED, can be used to predict the long-range response of metal electrodes in model electrochemical cells. In this work, we provide a full integration of SALTED with MetalWalls, a program for performing classical simulations of electrochemical systems. We do so by deriving a spherical harmonics extension of the Ewald summation method, which allows us to efficiently compute the electric field originated by the predicted electrode charge distribution. We show how to use this method to drive the molecular dynamics of an aqueous electrolyte solution under the quantum electric field of a gold electrode, which is matched to the accuracy of density-functional theory. Notably, we find that the resulting atomic forces present a small error of the order of 1 meV/Å, demonstrating the great effectiveness of adopting an electron-density path in predicting the electrostatics of the system. Upon running the data-driven dynamics over about 3 ns, we observe qualitative differences in the interfacial distribution of the electrolyte with respect to the results of a classical simulation. By greatly accelerating quantum-mechanics/molecular-mechanics approaches applied to electrochemical systems, our method opens the door to nanosecond timescales in the accurate atomistic description of the electrical double layer.
Force, inertia and motion from Aristotle to nowadays didactics
Authors: Bocci Franco 
Published: July 2024

Abstract
This study delves into the historical development of the core principles of dynamics, namely the interplay between forces and motion. We explore the intricate and nonlinear transition from the Aristotelian framework, which held sway for eighteen centuries, to the Newtonian paradigm. We posit that the complexity of this transition largely stems from what we perceive as an inadequate understanding of force. Our focus lies particularly on the seminal contributions of Galileo and the subsequent remarkable advancements made by Newton. However, we also note that, somewhat surprisingly, the transition does not conclude with Newton himself. What is commonly known as Newtonian dynamics in modern textbooks diverges significantly from the original theory outlined in the Principia, and we endeavour to elucidate these disparities. In the concluding sections, we scrutinise the implications of these concepts for contemporary teaching methodologies. Specifically, we delve into various interpretations of the Principle of Inertia, the Second Law, and their interrelationship, pinpointing what we perceive as weak points in current didactic approaches and proffering some suggestions for effectively imparting these concepts.
The three-dimensional harmonic oscillator and solid harmonics in Bargmann space
Authors: Sunko D K , Ciosłowski J 
Published: July 2024

Abstract
The three-dimensional harmonic oscillator is solved in Bargmann space. The treatment is pedagogically more transparent than the standard ones, at the price of introducing the Bargmann transform in the context of the one-dimensional oscillator. The standard solid harmonics are similarly derived with minimal technical effort, amounting to a complete self-contained exposition suitable for introductory courses in quantum mechanics or mathematical methods of physics. It provides an early exposure to wavelets, with important contemporary applications in signal analysis and quantum optics.
Highly efficient meta-lens integrated holographic surface antenna
Authors: Hao Yazheng , Yang Rui , Li Chunhui , Wang Yan 
Published: July 2024

Abstract
We demonstrate the generation of highly directive circularly polarized beams by proposing a meta-lens to calibrate the near fields over the holographic surface. Such a design possesses the merits of ultra-low profile as a lens system on the basis of phase compensation of a specific radiating aperture rather than the conventional consideration of the lens focus, and the ratio between the overall height of the antenna architecture and diameter of radiating aperture is only 0.09. Especially, the proposed meta-lens integrated holographic surface also offers a satisfactory solution to improve the overall efficiency of holographic antennas, and the experimental results verify the proposed design with 27.6 dBic measured gain and 40.4

%

aperture efficiency at 15 GHz. We expect the proposed strategy of integrating phase compensation lens closely over the holographic surface, pave the way for highly efficient meta-radiators with ultra-low profile.
Strain-dependence of Te interstitial diffusion in CdTe
Authors: Hamadna Sameer , Amar Jacques G 
Published: July 2024

Abstract
While the dominant defects which control non-radiative recombination and long-range interstitial diffusion in CdTe correspond to Cd vacancies and Te anti-sites, the short-range diffusion of Te and Se interstitials between these defects is also of interest, since they both play a role in defect passivation. In addition, since CdTe thin films are typically polycrystalline and may also involve interfaces with materials with different lattice constants, the effects of strain are also of interest. Here we present the results of molecular dynamics (MD) simulations of Te interstitial diffusion in zincblende CdTe for values of the triaxial strain ranging from −2% (compressive) strain to +2.8% (tensile) strain. By carrying out MD simulations of Te interstitial diffusion over a range of temperatures, and then carrying out Arrhenius fits, we have determined the effective activation barrier

E

a

and prefactor D
0 for each value of the global strain. We find that both

E

a

and D
0 exhibit non-monotonic behavior, increasing with both compressive and tensile strain. We also present an analysis of the key diffusion pathways for 3 different values of the strain which explains the non-monotonic strain dependence obtained in our simulations. Our results also indicate that in each case, the diffusion of interstitial Te involves a variety of concerted events with a wide range of activation barriers.
Optical response of Higgs mode in superconductors at clean limit: formulation through Eilenberger equation and Ginzburg–Landau Lagrangian
Authors: Yang F , Wu M W 
Published: July 2024

Abstract
Both macroscopic Ginzburg–Landau Lagrangian and microscopic gauge-invariant kinetic equation suggest a finite Higgs-mode generation in the second-order optical response of superconductors at clean limit, whereas the previous derivations through the path-integral approach and Eilenberger equation within the Matsubara formalism failed to give such generation. The crucial treatment leading to this controversy lies at an artificial scheme that whether the external optical frequency is taken as continuous variable or bosonic Matsubara frequency to handle the gap dynamics within the Matsubara formalism. To resolve this issue, we derive the effective action of the superconducting gap near Tc
in the presence of the vector potential through the path-integral approach, to fill in the long missing gap of the microscopic derivation of the Ginzburg–Landau Lagrangian in superconductors. It is shown that only by taking optical frequency as continuous variable within the Matsubara formalism, can one achieve the fundamental Ginzburg–Landau Lagrangian, and in particular, the finite Ginzburg–Landau kinetic term leads to a finite Higgs-mode generation at clean limit. To further eliminate the confusion of the Matsubara frequency through a separate framework, we apply the Eilenberger equation within the Keldysh formalism, which is irrelevant to the Matsubara space. By calculating the gap dynamics in the second-order response, it is analytically proved that the involved optical frequency is a continuous variable rather than bosonic Matsubara frequency, causing a finite Higgs-mode generation at clean limit.
An online comprehensive health monitoring system for automotive auxiliary converter
Authors: Wu Chenhao , Xia Qian , Cui Zhexin , Su Yongqing , Yue Jiguang , Lyu Feng 
Published: July 2024

Abstract
As an essential part of the electronic system in electric vehicles, the automotive auxiliary converter (AAC) connects the batteries and burdens the auxiliary power supply. This paper mainly proposes an online comprehensive health monitoring system for AAC. Firstly, based on the control diagram of the LLC resonant converter, three critical components are emerging, including capacitor, optocoupler, and semiconductor. These components can partly reflect the operation condition of the output loop, feedback loop, and control link, respectively. Then the characteristics parameters of these three components, equivalent series resistance of the capacitor, current transfer ratio of the optocoupler, and on-resistance of the semiconductor jointly construct the three-dimensional health monitoring vector. Finally, the online monitoring accuracy is verified and the proposed system can thus effectively promote the operation and maintenance of AAC. Furthermore, the online health monitoring system enables a flexible expansion, which can be further customized into different kinds of power converters, showing high applicability and practicality.
Measurement of air-water counter-current flow rates in vertical annulus using multiple differential pressure signals and machine learning
Authors: Cao Feng , Dang Ruirong , Dang Bo , Zheng Huifeng , Ji Anzhao , Chen Zhanjun 
Published: July 2024

Abstract
Gas–liquid counter-current flow in vertical annulus is involved in several industrial fields such as petroleum engineering. For example, in coalbed methane wells with liquid pump drainage, obtaining the real-time flow rate of gas–liquid two-phase in the annulus is crucial for the development management of coalbed methane wells. However, due to complex flow conditions, this demand is difficult to achieve through traditional flow metering means. Therefore, this paper proposes a flow prediction method based on multi-group differential pressure signals and machine learning technology. Air-water two-phase flow experiments were carried out on a vertical annulus pipeline with inner and outer diameters of 75 mm/125 mm and adjustable eccentricity. The probability density function and power spectrum density of 3 groups of differential pressure signals collected at different height intervals in the annulus were used as model inputs. A gas–liquid two-phase flow prediction model was constructed based on the artificial neural network model, and the model hyper-parameters were optimized using Bayesian optimization. The results show that on the 440-group test dataset under the combined conditions of air superficial velocity of 0.06–5.04 m s−1, water superficial velocity of 0.03–0.25 m s−1, and pipeline eccentricity of 0, 0.25, 0.5, 0.75, 1, etc. This model can achieve average prediction errors of 9.12% and 29.34% for gas and water flow rates respectively. This method can be applied to the non-throttling, non-invasive measurement of phase flow rate under the condition of annulus air-liquid counter-current flow.
The direction vector assisted INS/spectral redshift integrated navigation system for spacecraft
Authors: Peng Xu , Li Yan , Hu Gaoge , Gao Guangle 
Published: July 2024

Abstract
A reliable and autonomous navigation system is crucial for achieving high survivability of spacecraft. As a novel autonomous navigation system, an inertial/spectral redshift (INS/SRS) integrated navigation system can correct the navigation errors of INS through redshift and direction vector information from celestial bodies. However, since SRS needs to obtain position measurements by integrating the velocity information of the spacecraft, the position error from INS/SRS diverges. Therefore, this paper investigates a direction vector-assisted INS/SRS integrated navigation system for spacecraft. It examines the relationship among the position of the spacecraft, redshift, and direction vectors from celestial bodies. Then, a direction vector-assisted SRS is proposed, which can solve the position information of spacecraft directly by using redshift and direction vector information. Finally, the direction vector-assisted SRS is combined with INS to form the direction vector-assisted INS/SRS integrated navigation system. Simulations and comprehensive analysis demonstrate that the proposed integrated navigation system has better performance than the conventional INS/SRS integrated navigation system.
Dynamic characteristic analysis and key parameter optimization of throttling orifice type air damping air spring
Authors: Chen Junjie , Huang Ziqi , Kang Sheng , Yang Qin , Yuan Xianju , Huang Peng , Gan Yu Feng 
Published: July 2024

Abstract
The unique hysteretic characteristic of rubber bellows and the nonlinear flow of internal airflow in the system results in the significant nonlinear dynamic characteristic of throttling orifice type air damping air springs (OADASs). To solve the problem of mathematical representation of dynamic characteristic and key parameters optimization of throttling OADAS, this paper comprehensively considers the hysteretic characteristic of rubber bellows under variable pressure, the nonlinear dynamic characteristic model and linear model of throttling OADAS are established based on the concepts of gas thermodynamics and fluid mechanics. The static and dynamic characteristic tests of the throttling OADAS are conducted, to verify the accuracy and effectiveness of the proposed model, and to reveal the influence laws of excitation amplitude, excitation frequency, and throttling orifice diameter on the quantitative characterization indexes. Finally, a complete throttling orifice diameter optimization method is proposed based on the eight-degree-of-freedom model of the entire vehicle. Optimization results illustrate that the RMS values of the vertical acceleration of the body and the vertical acceleration of the driver are decreased by 19.02% and 38.44%, respectively. Overall, the outcomes of this paper can provide the design idea and theoretical basis for air damping matching and active suspension control.
Influence of cutoff radius and tip atomic structure on energy barriers encountered during AFM tip sliding on 2D monolayers
Authors: Lim Jaehun , Moon Donghyeon , Kim Sunghyun , Kim Suenne 
Published: July 2024

Abstract
In computational studies using the Lennard–Jones (LJ) potential, the widely adopted 2.5 σ cutoff radius effectively truncates pairwise interactions across diverse systems (Santra et al 2008 J. Chem. Phys.
129 234704, Chen and Gao 2021 Friction
9 502–12, Bolintineanu et al 2014 Part. Mech.
1 321–56, Takahiro and Kazuhiro 2010 J. Phys.: Conf. Ser.
215 012123, Zhou et al 2016 Fuel
180 718–26, Toxvaerd and Dyre 2011 J. Chem. Phys.
134 081102, Toxvaerd and Dyre 2011 J. Chem. Phys.
134 081102). Here, we assess its adequacy in determining energy barriers encountered by a Si monoatomic tip sliding on various two-dimensional (2D) monolayers, which is crucial for understanding nanoscale friction. Our findings emphasize the necessity of a cutoff radius of at least 3.5 σ to achieve energy barrier values exceeding 95% accuracy across all studied 2D monolayers. Specifically, 3.5 σ corresponds to 12.70 Å in graphene, 12.99 Å in MoS2 and 13.25 Å in MoSe2. The barrier values calculated using this cutoff support previous experiments comparing friction between different orientations of graphene and between graphene and MoS2 (Almeida et al 2016 Sci. Rep.
6 31569, Zhang et al 2014 Sci. China
57 663–7). Furthermore, we demonstrate the applicability of the 3.5 σ cutoff for graphene on an Au substrate and bilayer graphene. Additionally, we investigate how the atomic configuration of the tip influences the energy barrier, finding a nearly threefold increase in the barrier along the zigzag direction of graphene when using a Si(001) tip composed of seven Si atoms compared to a monoatomic Si tip.
Non-invasive pulse arrival time is associated with cardiac index in pediatric heart transplant patients with normal ejection fraction
Authors: Kwon Soon Bin , Weinerman Bennett , Nametz Daniel , Megjhani Murad , Lee Isaac , Habib Anthony , Barry Oliver , Park Soojin 
Published: July 2024

Abstract

Objective. Cardiac Index (CI) is a key physiologic parameter to ensure end organ perfusion in the pediatric intensive care unit (PICU). Determination of CI requires invasive cardiac measurements and is not routinely done at the PICU bedside. To date, there is no gold standard non-invasive means to determine CI. This study aims to use a novel non-invasive methodology, based on routine continuous physiologic data, called Pulse Arrival Time (PAT) as a surrogate for CI in patients with normal Ejection Fraction (EF). Approach. Electrocardiogram (ECG) and photoplethysmogram (PPG) signals were collected from beside monitors at a sampling frequency of 250 samples per second. Continuous PAT, derived from the ECG and PPG waveforms was averaged per patient. Pearson’s correlation coefficient was calculated between PAT and CI, PAT and heart rate (HR), and PAT and EF. Main Results. Twenty patients underwent right heart cardiac catheterization. The mean age of patients was 11.7 ± 5.4 years old, ranging from 11 months old to 19 years old, the median age was 13.4 years old. HR in this cohort was 93.8 ± 17.0 beats per minute. The average EF was 54.4 ± 9.6%. The average CI was 3.51 ± 0.72 l min−1 m−2, with ranging from 2.6 to 4.77 l min−1 m−2. The average PAT was 0.31 ± 0.12 s. Pearson correlation analysis showed a positive correlation between PAT and CI (0.57, p < 0.01). Pearson correlation between HR and CI, and correlation between EF and CI was 0.22 (p = 0.35) and 0.03 (p = 0.23) respectively. The correlation between PAT, when indexed by HR (i.e. PAT × HR), and CI minimally improved to 0.58 (p < 0.01). Significance. This pilot study demonstrates that PAT may serve as a valuable surrogate marker for CI at the bedside, as a non-invasive and continuous modality in the PICU. The use of PAT in clinical practice remains to be thoroughly investigated.
Longitudinal-twist wave converter based on chiral metamaterials
Authors: Lemkalli Brahim , Kadic Muamer , El Badri Youssef , Guenneau Sébastien , Mir Abdellah , Achaoui Younes 
Published: July 2024

Abstract
Advances in material architectures have enabled endowing materials with exotic attributes not commonly available in the conventional realm of mechanical engineering. Twisting, a mechanism whereby metamaterials are used to transform static axial load into twist motion, is of particular interest to this study. Herein, computations based on the finite element method, corroborated by a theoretical approach derived from applying Lagrange’s equations to a monoatomic spring-mass system, are employed to explore the longitudinal-twist (L-T) conversion exhibited by a chiral tetragonal-beam metamaterial. Firstly, we perform an eigenvalue analysis taking into account the polarization states to highlight the contribution of the longitudinal mode in the L-T conversion. We contrast the twisting behavior of the chiral cell with that of other homogeneous medium, octagonal-tube, and non-chiral cells. Moreover, we demonstrate the influence of the cell’s chirality on the L-T conversion using both time-domain and frequency-domain studies. The findings indicate that at least a portion of the longitudinally propagating wave is transformed into twist throughout a broad frequency range and even quasi-totally converted at distinct frequencies.
Rhodian Epigraphic Culture and Society
Authors: Zachhuber Juliane 
Published: July 2024

AbstractThis chapter considers the aftermath of the Rhodian synoecism and the historical developments of the new social and political creation of Rhodes throughout the Hellenistic period. It does this first by focusing on historiographical accounts (in particular by non-Rhodian observers), sketching the well-known image of the successful maritime commercial centre, a melting pot in the south-eastern Aegean, governed by a democracy, but with a powerful aristocracy. The chapter then shifts to consider the ample evidence of epigraphy, and to what extent the picture provided by Rhodian epigraphic culture maps onto that projected by historians. An analysis of Rhodian epigraphy illuminates striking local divergences and the importance of sanctuaries as spaces for epigraphic display, as well as offering a clear picture of how Rhodians presented and saw themselves and their society.
Gods of the Rhodian State: Helios and Athena
Authors: Zachhuber Juliane 
Published: July 2024

AbstractRhodian religion was dominated by two gods: Helios and Athena. This chapter digs into the religious significance and cultic presence of both deities. Helios was chosen as the new patron deity of the unified Rhodian state, giving him an unusually prominent poliad position in the late classical Greek world. Much about his cult remains uncertain, including the precise location of his sanctuary, and how he was worshipped. This section suggests seeing the famous Colossus primarily as a religious offering, and further explores the similarities between Helios and other gods, including Apollo and Poseidon, as well as his long-lasting perception as a Rhodian god. Athena has a much longer cultic presence on Rhodes, and provides us with a much greater body of evidence. Her local cults are compared in terms of their sites and their worshippers, and commonalities and idiosyncrasies are drawn out.