bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cryogenic DRIE processes for high-precision silicon etching in MEMS applications
Authors: Horstmann Benjamin , Pate David , Smith Bennett , Mamun Md Ataul , Atkinson Gary , Özgür Ümit , Avrutin Vitaliy 
Published: June 2024

Abstract
Cryogenic deep reactive ion etching (Cryo DRIE) of silicon has become an enticing but challenging process utilized in front-end fabrication for the semiconductor industry. This method, compared to the Bosch process, yields vertical etch profiles with smoother sidewalls not subjected to scalloping, which are desired for many microelectromechanical systems (MEMS) applications. Smoother sidewalls enhance electrical contact by ensuring more conformal and uniform sidewall coverage, thereby increasing the effective contact area without altering contact dimensions. The versatility of the Cryo DRIE process allows for customization of the etch profiles by adjusting key process parameters such as table temperature, O2 percentage of the total gas flow rate (O2 + SF6), RF bias power and process pressure. In this work, we undertake a comprehensive study of the effects of Cryo DRIE process parameters on the trench profiles in the structures used to define cantilevers in MEMS devices. Experiments were performed with an Oxford PlasmaPro 100 Estrelas ICP-RIE system using positive photoresist SPR-955 as a mask material. Our findings demonstrate significant influences on the sidewall angle, etch rate and trench shape due to these parameter modifications. Varying the table temperature between −80 °C and −120 °C under a constant process pressure of 10 mTorr changes the etch rate from 3 to 4 μm min−1, while sidewall angle changes by ∼2°, from positive (<90° relative to the Si surface) to negative (>90° relative to the Si surface) tapering. Altering the O2 flow rate with constant SF6 flow results in a notable 10° shift in sidewall tapering. Furthermore, SPR-955 photoresist masks provide selectivity of 46:1 with respect to Si and facilitates the fabrication of MEMS devices with precise dimension control ranging from 1 to 100 μm for etching depths up to 42 μm using Cryo DRIE. Understanding the influence of each parameter is crucial for optimizing MEMS device fabrication.
Efficient synthesis of CO and H2O2 via nanosecond pulsed CO2 bubble discharge
Authors: Gao Yuting , Zhou Renwu , Hong Longfei , Chen Bohan , Sun Jing , Zhou Rusen , Liu Zhijie 
Published: June 2024

Abstract
In the context of escalating global efforts to mitigate carbon emissions and explore sustainable energy resources, the transformation of CO2 into valuable chemicals and fuels via plasma technology has garnered significant attention. This study demonstrated a new pathway of CO2 conversion into CO and H2O2 via the bubble-enabled gas-liquid discharge driven by a nanosecond pulse. Results showed that the increased discharge frequency and larger pulse widths could enhance CO2 conversion rates and H2O2 yields, albeit potentially at the cost of reduced energy efficiency. Conversely, the rising time of pulse showed negligible impact on the process, whereas varying gas flow rates significantly altered CO and H2O2 yields, underscoring the nuanced influence of these parameters on the efficiency and selectivity of conversion processes. Through illuminating the dynamics of bubble discharge-assisted CO2 transformation, this study contributes to the broader understanding of gas-liquid discharge driven by nanosecond pulse, underlining its potential for addressing environmental and energy challenges.
Simulation of electrical rectification effect in two-dimensional MoSe2/WSe2 lateral heterostructures
Authors: Zhou Yao-Hong , Dang Zhi-Min , Wang Hai-Dong 
Published: June 2024

Abstract
Two-dimensional (2D) transition metal dichalcogenides lateral heterostructures exhibit excellent performance in electrics and optics. The electron transport of the heterostructures can be effectively regulated by ingenious design. In this study, we construct a monolayer MoSe2/WSe2 lateral heterostructure, covalently connecting monolayer MoSe2 and monolayer WSe2. Using the Extended Huckel Theory method, we explored current-voltage characteristics under varied conditions, including altering carrier density, atomic replacement and interface angles. Calculations demonstrate a significant electrical rectification ratio (ERR) ranging from 200 to 800. Additionally, Employing Density Functional Theory with non-equilibrium Green’s function method, we investigated electronic properties, attributing the rectification effect to electronic state distribution differences, asymmetric transmission coefficients and band bending of projected local density of states. The expandability of the interfacial energy barrier enhances the rectification effect through adjustments in carrier concentration, atomic replacements and interface size. However, these enhancements introduce challenges such as increased electron-boundary scattering and reduced ambipolarity, resulting in a lower ERR. This study provides valuable theoretical insights for optimizing 2D electronic diode devices, offering avenues for precise control of the rectification effect.
Comparative study on the magnetic properties of Fe-substituted Co2Sn1−x
Fe
x
O4 spinel oxides and its exchange bias effect
Authors: Ali Wajahat , Xinghan Chen , Hongxia Yin , Zhilong Zheng , Songliu Yuan 
Published: June 2024

Abstract
Herein, we report the Fe-substituted Co2Sn1−x
Fe
x
O4 (0 ⩽ x ⩽ 0.4) inverse spinel’s oxide using the solid-state reaction method. X-ray reveals the single-phase cubic structure with space group Fd3m. With increasing Fe in Co2Sn1−x
Fe
x
O4 spinel oxide, the transition temperature rise. The ac susceptibility at different frequencies also confirms a spin-glassy state at lower temperatures. The strong exchange bias effect appears in the sample having Fe substitution (x = 0.2) under the presence of constant temperature ∼10 K. The high-temperature susceptibility of Curie-Wise fitting shows that the system changes from antiferromagnetic exchange (x < 0.2) to ferromagnetic exchange (x > 0.2).
Pencil and paper electronics: an accessible approach to teaching basic physics concepts
Authors: Bastante Pablo , Castellanos-Gomez Andres 
Published: June 2024

Abstract
This teaching article describes a simple and low-cost methodology for studying electrical transport and constructing basic sensor devices using everyday stationery items, including pencils, paper, and a handheld multimeter. The approach is designed for high school and undergraduate teachers and offers an easy-to-implement, hands-on method for teaching fundamental concepts in physical electronics. The materials and experiments outlined in this article are widely accessible and can be easily replicated in various teaching labs, even with limited budgets.
AC transport loss analysis of HTS stack busbars for all-electric aircraft with harmonics and DC offset considerations
Authors: Abdioglu Murat , Gautam Gaurav , Zhang Min , Yuan Weijia 
Published: June 2024

Abstract
This paper presents a study of the current carrying capacity and AC loss of high-temperature superconducting (HTS) stacks to be used in busbar applications for all-electric aircraft. A 2D model was developed using COMSOL Multiphysics with a T-A formulation for detailed analysis. The study began by applying a stable 20 kA DC offset current to the HTS stacks to simulate practical operating conditions. Firstly, the behaviour of the critical current was studied under self-field conditions for stacks with different numbers of HTS tapes and spacing. Secondly, AC ripple currents were introduced with DC offsets, and the effects of 3rd and 5th harmonic distortions (HD) were studied. The results show that configurations with 40 tapes and gaps of more than 2 mm are considered suitable for safe current transport under DC conditions. On the other hand, increasing the tape spacing leads to an increase in the safe transport current ripple due to the reduced magnetic field interaction within the stack. In addition, the transport loss decreases as the air gap increases due to the reduction in the self-field, whereas it increases as the number of strips increases. The influence of the 3rd HD on the transport loss is minimal at a ripple current of 1% and slightly noticeable at 2%. However, it becomes more obvious as the ripple current approaches the critical value. Remarkably, even cases with equivalent total HD show significantly higher transport losses when characterised by higher 5th HD than their counterparts with 3rd HD. This comprehensive analysis provides valuable information on the performance characteristics of HTS stacks in all-electric aircraft busbar applications and offers important insights for the development and optimisation of these systems in practical aerospace applications.
Derivation of dirac exchange interaction potential from quantum plasma kinetic theory
Authors: Haas Fernando 
Published: June 2024

Abstract
The Dirac exchange interaction is derived from recent quantum kinetic theory for collisionless plasmas. For this purpose, the kinetic equation is written in the semiclassical and long wavelength approximations. The validity of the model for real systems is worked out, in terms of temperature and density parameters. Within the region of applicability, the correlation potential energy is shown to be always smaller than the exchange contribution. From the moments of the quantum kinetic equations, macroscopic, hydrodynamic equations are found, for an electron-ion plasma. The Dirac exchange term is explicitly derived, in the case of a completely degenerate electron gas. These results show, within quantum kinetic theory for charged particle systems, a new view of the Dirac exchange interaction frequently used in density functional theory parametrization. Finally, a simpler form of the quantum plasma exchange kinetic theory is also found.
Soft contributions to the thermal Higgs width across an electroweak phase transition
Authors: Eriksson M. , Laine M. 
Published: June 2024

Abstract
We estimate the equilibration rate of
a nearly homogeneous Higgs field,
displaced from its ground state during the onset
of an electroweak phase transition.
The computation is carried out with Hard Thermal Loop
resummed perturbation theory, and a significant
part of the result originates from Bose-enhanced
t-channel 2 ↔ 2 scatterings.
The expression is shown to be IR finite and gauge independent.
Possible applications to Langevin simulations of bubble nucleation
are mentioned, and we also contrast with
the friction affecting bubble growth.
Mapping the antiparallel aligned domain rotation by microwave excitation
Authors: Zhang 张 Jing 景 , Cui 崔 Yuanzhi 远志 , Wang 王 Xiaoyu 晓雨 , Wang 王 Chuang 创 , Liu 刘 Mengchen 梦晨 , Xu 徐 Jie 洁 , Li 李 Kai 凯 , Zhao 赵 Yunhe 芸鹤 , Lu 陆 Zhenyan 振烟 , Pan 潘 Lining 丽宁 , Jin 金 Chendong 晨东 , Liu 刘 Qingfang 青芳 , Wang 王 Jianbo 建波 , Cao 曹 Derang 德让 
Published: June 2024

Abstract
The evolution process of magnetic domains in response to external fields is crucial for the modern understanding and application of spintronics. In this study, we investigated the domain rotation in stripe domain films of varying thicknesses by examining their response to microwave excitation in four different orientations. The resonance spectra indicate that the rotation field of stripe domain film under an applied magnetic field approaches the field where the resonance mode of sample changes. The saturation field of the stripe domain film corresponds to the field where the resonance mode disappears when measured in the stripe direction parallel to the microwave magnetic field. The results are reproducible and consistent with micromagnetic simulations, providing additional approaches and techniques for comprehending the microscopic mechanisms of magnetic domains and characterizing their rotation.
Effect of antioxidants on the efficiency of jet milling and the powder characteristics of Sm2Co17 permanent magnets
Authors: Xu 许 Da-Shuai 大帅 , Liu 刘 Lei 雷 , Yuan 袁 Jian-Hui 建辉 , Zhou 周 Bo 波 , Dong 董 Chuang-Hui 创辉 , Wang 王 Feng-Qing 凤青 , Ding 丁 Yong 勇 , Sun 孙 Ying-Li 颖莉 , Yan 闫 A-Ru 阿儒 
Published: June 2024

Abstract
This study investigated the effect of antioxidants on the grinding efficiency, magnetic powder characteristics, microstructure, and magnetic properties of 2:17 type SmCo permanent magnet materials. The results show that adding antioxidants helps improve the dispersion among magnetic powders, leading to a 33.3% decrease in jet milling time and a 15.8% increase in magnet powder production yield. Additionally, adding antioxidants enhances the oxidation resistance of the magnetic powders. After being stored in a constant temperature air environment at 25 °C for 48 h, the O content in the powder decreased by 33% compared to samples without antioxidants. While in the magnet body, the O content decreased from 0.21 wt.% to 0.14 wt.%, which helps increase the effective Sm content and domain wall pinning uniformity in the magnet. Excellent magnetic properties were obtained in the magnet with added antioxidants: B
r = 11.6 kGs, SF = 79.6%, H
cj = 16.8 kOe, and (BH)max = 32.5 MGOe.
Observation of modes in the sub-cyclotronic range of frequencies in JET
Authors: Nabais F. , Borba D. , Coelho R. , Ferreira J. , Figueiredo A. , Rodrigues P. , Sharapov S.E. ,   JET Contributors
Published: June 2024

Abstract
The excitation of modes in the JET tokamak in the sub-cyclotronic range of frequencies (frequencies comprised between the Alfvén frequency and the cyclotron frequency) is for the first time reported. The modes were identified as compressional Alfvén eigenmodes and have characteristics similar to those of the sub-cyclotronic modes observed in other tokamaks, in particular those first reported in the NSTX tokamak. On the other hand, the modes observed in JET present some unique features and were observed to be excited by ion cyclotron resonance heating instead of by the injection of beams (neutral beam injection).
The Jahn-Teller Effects in Chemical Reactions and Materials Science
Authors: Bersuker I. B. 
Published: June 2024

Abstract
In a semi-review paper (a review with novel results included), we note first that the so-called Jahn-Teller effects (JTEs), in their presently recognized four modifications, emerge as particular cases of a more general law, stating that “Nature tends to avoid degeneracies and pseudo-degeneracies in atomic matter by means of spontaneous symmetry breaking (SSB)”. This “Law of Nature” obviously influences all the relevant properties of polyatomic systems, including those with direct applications in materials science and engineering, as well as in materials transformations, notably, in chemical reactions. The exploration to the latter is quite novel: we show that the energy barriers in chemical transformations are controlled by the pseudo-JTE (PJTE), opening uncharted ways of catalytic action. The applications of JTEs theory in materials science is already more advanced, utilizing the SSB-induced special nuclear dynamics, which is very sensitive to external perturbations. One of its novel aspects is to modify the properties of the system by means of external influence targeting its JTEs parameters, their underlying degeneracies. We show here some notable trends with illustrative examples, including the JTEs in local centers in crystals used as qubits in quantum information storage, alteration of whole crystal lattice properties by inducing the JTE in one of its sublattices, planarization of puckered (buckled) two-dimensional systems by coordination to atoms that quench their PJTE-induced out-of-plane distortion, and the origin of a whole series of solid state properties of perovskite crystals, triggered by the local PJTE.
Quantum dynamics of the Jahn-Teller complexes investigated by ultrasonic technique
Authors: Gudkov V V , Averkiev N S , Zhevstovskikh I V , Sarychev M N 
Published: June 2024

Abstract
Ultrasonic technique has been used for investigation of the dynamics of the Jahn-Teller complexes in doped fluorite crystals. We use ultrasonic technique to measure temperature dependence of the real and imaginary parts of the dynamic elastic modulus of Jahn-Teller complexes. These data are used to determine the relaxation time of the distribution function over the vibronic states, which are characterized by the symmetrized deformations of the complexes. Three mechanisms of relaxation have proved to define the total relaxation time. They are thermal activation over the potential energy barriers, two-phonon mechanism, and tunneling through the barriers. The last mechanism leads to the non-zero ultrasonic attenuation and linear temperature dependence of phase velocity of the wave at low temperatures. Quantum nature of the relaxation mechanisms makes it possible to refer the Jahn-Teller effect manifestation in the mechanical properties of a crystal to the field of quantum acoustics.
Design and evaluation of a symmetric amplification mechanism based anthropomorphic shoulder
Authors: Wu Jiahao , Wan Guangfu , Liang Jiejunyi 
Published: June 2024

Abstract
Shoulder joints determine the motion range of the upper limb. Thus, the compact and well-stiffened spherical parallel mechanism (SPM) has emerged as the mainstream shoulder prosthesis design approaches. However, the SPM’s moving pairs of redundant motions impose excessive constraints that limit its workspace. Therefore, amplifying the workspace of the SPM to cover the motion range required by human daily activities is a pressing problem in shoulder prosthesis design. To address this challenge, this study proposed a workspace amplification approach through the kinematic analysis of a symmetrically arranged 2 degrees of freedom (DoFs) passive mechanism, together with the designed and optimized 3-RRR SPM, to construct an anthropomorphic shoulder. The effectiveness and reliability of the proposed mechanism was verified through thorough analyses. Simulation and experiment results demonstrated that the workspace amplification mechanism could significantly increase the maximum motion match index between the shoulder prosthesis and the daily workspace of the human shoulder from only 26.3% to 94.79%, solving the problem that the traditional SPM-based prostheses cannot satisfy the motion range required by daily activities. Moreover, the proposed mechanism has the potential to amplify the workspace of most parallel mechanisms with multiple DoFs after proper modification.
Stability and chaos in dynamical last passage percolation
Authors: Ganguly Shirshendu , Hammond Alan 
Published: June 2024

Many complex disordered systems in statistical mechanics are characterized by intricate energy landscapes. The ground state, the configuration with lowest energy, lies at the base of the deepest valley. In important examples, such as Gaussian polymers and spin glass models, the landscape has many valleys and the abundance of near-ground states (at the base of valleys) indicates the phenomenon of chaos, under which the ground state alters profoundly when the disorder of the model is slightly perturbed. In this article, we compute the critical exponent that governs the onset of chaos in a dynamic manifestation of a canonical model in the Kardar-Parisi-Zhang [KPZ] universality class, Brownian last passage percolation [LPP]. In this model in its static form, semidiscrete polymers advance through Brownian noise, their energy given by the integral of the white noise encountered along their journey. A ground state is a geodesic, of extremal energy given its endpoints. We perturb Brownian LPP by evolving the disorder under an Ornstein-Uhlenbeck flow. We prove that, for polymers of length

n
n

, a sharp phase transition marking the onset of chaos is witnessed at the critical time

n

−
1

/

3

n^{-1/3}

. Indeed, the overlap between the geodesics at times zero and

t
>
0

t > 0

that travel a given distance of order

n
n

will be shown to be of order

n
n

when

t
≪

n

−
1

/

3

t\ll n^{-1/3}

; and to be of smaller order when

t
≫

n

−
1

/

3

t\gg n^{-1/3}

. We expect this exponent to be universal across a wide range of interface models. The present work thus sheds light on the dynamical aspect of the KPZ class; it builds on several recent advances. These include Chatterjee’s harmonic analytic theory [Superconcentration and related topics, Springer, Cham, 2014] of equivalence of superconcentration and chaos in Gaussian spaces; a refined understanding of the static landscape geometry of Brownian LPP developed in the companion paper (see S. Ganguly and A. Hammond [Electron. J. Probab. 28 (2023), 80 pp.]); and, underlying the latter, strong comparison estimates of the geodesic energy profile to Brownian motion (see J. Calvert, A. Hammond, and M. Hegde [Astérisque 441 (2023), pp. v+119]).
Heritage Type, Demographics, and Context
Authors: Sayer Faye 
Published: June 2024

Abstract
This chapter compares how diverse heritage places including heritage sites, archaeological sites, museums, and art galleries impact visitors’ subjective wellbeing. Comparative analysis will identify trends in capabilities of subjective visitor wellbeing impacted by different types of heritage place, seeking to uncover how specific types of heritage places impact hedonic and eudaimonic wellbeing. The chapter examines how the national context in which heritage places are situated impacts on their potential to improve visitors’ subjective wellbeing and uncovers how organizational practices and interpretative approaches applied at heritage places can impact visitors’ wellbeing. The chapter provides evidence of how visitors’ age, gender, or disability impacts heritage places’ ability to improve their subjective wellbeing. It considers if demographic patterns in the wellbeing impact of heritage places can be identified across national boundaries. It provides empirical evidence to help organizations to understand the role of heritage places nationally in improving individuals’ subjective wellbeing and considers the potential of these sites to tackle societal wellbeing inequalities related to age, gender, and disability.
Healthier Societies through Heritage
Authors: Sayer Faye 
Published: June 2024

Abstract
This book has sought to provided internationally applicable evidence of the impact of heritage places on visitors’ subjective wellbeing. The breath and robust nature of this research enables this chapter to present guidelines and strategies for future best practice for heritage projects to support visitor’s personal and social wellbeing, but also to develop programmes and projects specifically tailored to support wider community wellbeing. At this critical juncture in well-being policy and practice, the research presented in this book has demonstrated that the heritage sector has value to society and can support the global societal goals such as reducing wellbeing inequality and creating healthier societies.