bluuebunny/crossref_metadata_2025 huggingface dataset:
Update in Pediatric Neurocritical Care: What a Neurologist Caring for Critically Ill Children Needs to Know
Authors: Plante Virginie , Basu Meera , Gettings Jennifer V. , Luchette Matthew , LaRovere Kerri L. ,   The Pediatric Critical Nervous System Program (pCNSp)
Published: May 2024

Currently nearly one-quarter of admissions to pediatric intensive care units (PICUs) worldwide are for neurocritical care diagnoses that are associated with significant morbidity and mortality. Pediatric neurocritical care is a rapidly evolving field with unique challenges due to not only age-related responses to primary neurologic insults and their treatments but also the rarity of pediatric neurocritical care conditions at any given institution. The structure of pediatric neurocritical care services therefore is most commonly a collaborative model where critical care medicine physicians coordinate care and are supported by a multidisciplinary team of pediatric subspecialists, including neurologists. While pediatric neurocritical care lies at the intersection between critical care and the neurosciences, this narrative review focuses on the most common clinical scenarios encountered by pediatric neurologists as consultants in the PICU and synthesizes the recent evidence, best practices, and ongoing research in these cases. We provide an in-depth review of (1) the evaluation and management of abnormal movements (seizures/status epilepticus and status dystonicus); (2) acute weakness and paralysis (focusing on pediatric stroke and select pediatric neuroimmune conditions); (3) neuromonitoring modalities using a pathophysiology-driven approach; (4) neuroprotective strategies for which there is evidence (e.g., pediatric severe traumatic brain injury, post–cardiac arrest care, and ischemic stroke and hemorrhagic stroke); and (5) best practices for neuroprognostication in pediatric traumatic brain injury, cardiac arrest, and disorders of consciousness, with highlights of the 2023 updates on Brain Death/Death by Neurological Criteria. Our review of the current state of pediatric neurocritical care from the viewpoint of what a pediatric neurologist in the PICU needs to know is intended to improve knowledge for providers at the bedside with the goal of better patient care and outcomes.
Diagrammatic representation and nonperturbative approximations of the exact time-convolutionless master equation
Authors: Gu Bing
Published: May 2024

The time-convolutionless master equation provides a general framework to model the non-Markovian dynamics of an open quantum system with a time-local generator. A diagrammatic representation is developed and proven for the perturbative expansion of the exact time-local generator for an open quantum system interacting with arbitrary environments. A truncation of the perturbation expansion leads to perturbative time-convolutionless quantum master equations. We further introduce a general iterative approach to construct nonperturbative approximations for the time-local generator as nested time-ordered exponential operators.
Development of a high-performance arithmetic and logic unit for efficient digital signal processing based on reversible logic and quantum dots
Authors: Jun Hu , Wei Xiao , Anbar Mohammad
Published: May 2024

Digital Signal Processing (DSP) finds a wide range of applications in various fields, including telecommunications, audio and video processing, biomedical engineering, radar systems, and image processing. Previous DSP designs faced limitations in available processing power and computational resources. Insufficient processing power could result in slower execution times, an inability to handle complex algorithms, or limited capacity to process high-speed or large-scale signals. As the demand for minimal power consumption in DSP circuits continues to grow, reversible logic and quantum-dot cellular automata (QCA) have emerged as promising technologies due to their inherent ability to reduce energy loss. Within this landscape, the arithmetic and logic unit (ALU) plays a vital role in complex circuitry, serving as a key component in digital signal processing applications. However, challenges persist, including high quantum cost and the need to limit the number of cells in the ALU design. To address these challenges, our research aims to develop an efficient ALU by integrating reversible logic and QCA technology. Our focus will be on generating essential components, such as Feynman gates, Fredkin gates, and full adder circuits, which serve as foundational building blocks for reversible logic and QCA designs. These components will be combined to construct a comprehensive ALU capable of performing 20 different operations. Our implementation efforts will be centered around QCADesigner, with a specific emphasis on digital signal processing systems that prioritize energy efficiency and optimal utilization of occupied areas.
Parallel compressive super-resolution imaging with wide field-of-view based on physics enhanced network
Authors: Jin Xiao-Peng , Xiong An-Dong , Liu Fan , Wang Xiao-Qing , Zhang Wei , Li Chang-Heng , Yao Xu-Ri , Liu Xue-Feng , Zhao Qing
Published: May 2024

Parallel compressive super-resolution imaging has attracted increasing attention in recent years. However, the super-resolution quality depends on modulation masks and reconstruction algorithms. A deep-learning method provides an efficient solution, but in wide field-of-view (FOV) scenarios, the differences between optical transfer functions (OTFs) of each pixel increase the system complexity and limit its practical application. This study proposed a wide FOV parallel compressive super-resolution imaging approach based on a physics-enhanced network. First, the network and modulation masks of an arbitrary 128 × 128-pixel region were trained; then, the trained network was fine-tuned for the rest of the 128 × 128-pixel regions in the entire wide FOV, which effectively eliminated the OTF variability. Numerical simulations and practical experiments demonstrated that through the proposed approach, super-resolution images of 1020 × 1500 pixels can be reconstructed from 272 × 400-pixel low-resolution measurements using only three designed masks, with the resolution enhanced 3.75×3.75 times and the peak signal-to-noise ratio improved by 89.4% compared to the results of the previous compressed sensing algorithm. Besides, the training time was dramatically reduced by 95.5-fold compared with the traditional training strategy for each region alone. This approach decreases the imaging complexity of wide FOV and achieves the high-quality super-resolution reconstruction under few trained masks, thus we believe it can promote rapid imaging for super-resolution and a wide FOV ranging from infrared to terahertz.
Engineering quantum dots for improved single photon emission statistics
Authors: Roy Parna , Pandey Anshu
Published: May 2024

High fidelity single photon sources are required for the implementation of quantum information processing and communications protocols. Although colloidal quantum dots (CQDs) are single photon sources, their efficacy is limited by their tendency to show finite multiphoton emission at higher excitation powers. Here, we show that wave function engineering of CQDs enables the realization of emitters with significantly improved single photon emission performance. We study the ZnS/CdSe/CdS system. It is shown that this system offers significantly improved probabilities of single photon emission. While conventional CQDs such as CdSe/CdS exhibit a g2(0) > 0.5 ± 0.02 at ⟨N⟩ = 2.17, ZnS/CdSe/CdS show a greatly improved g2(0) ≈ 0.04 ± 0.01. Improved single photon emission performance encourages the use of colloidal materials as quantum light sources in emerging quantum devices.
Sensitive detection and imaging of H2O density through Rydberg resonant femtosecond laser induced photofragmentation fluorescence
Authors: Livingston Large Timothy A. , Kliewer Christopher J.
Published: May 2024

A femtosecond laser induced photofragmentation fluorescence (fs-LIPF) scheme for the sensitive detection and imaging of water vapor is presented. Two photons of 244.3 nm excite water to the D̃ state and produce hydroxyl radicals in the fluorescing Ã state. Two more photons promote electrons from the D̃ state to a neutral Rydberg state of the (1b2)−1 ionic core through a 2 + 2 doubly resonant process. The resulting high-lying Rydberg state undergoes neutral dissociation, and the energetic hydrogen fragments are detected from their Balmer series fluorescence. These channels (in the low-pressure limit) have detection sensitivities around 1012 molecules per cubic centimeters, orders of magnitude more sensitive than laser-induced fluorescence based approaches, allowing for sensitive non-invasive detection and imaging of water density for many important processes.
Performance assessment of the effective core potentials under the fermionic neural network: First and second row elements
Authors: Wang Mengsa , Zhou Yuzhi , Wang Han
Published: May 2024

The rapid development of deep learning techniques has driven the emergence of a neural network-based variational Monte Carlo (VMC) method (referred to as FermiNet), which has manifested high accuracy and strong predictive power in the electronic structure calculations of atoms, molecules, and some periodic systems. Recently, the implementation of the effective core potential (ECP) scheme has further facilitated more efficient calculations in practice. However, there is still a lack of comprehensive assessments of the ECP’s performance under the FermiNet. In this work, we set sail to fill this gap by conducting extensive tests on the first two row elements regarding their atomic, spectral, and molecular properties. Our major finding is that, in general, the qualities of ECPs have been correctly reflected under FermiNet. Two recently built ECP tables, namely, correlation consistent ECP (ccECP) and energy consistent correlated electron pseudopotential (eCEPP), seem to prevail in terms of overall performance. In particular, ccECP performs slightly better on spectral precision and covers more elements, while eCEPP is more systematically built from both shape and energy consistency and better treats the core polarization. On the other hand, the high accuracy of the all-electron calculations is hindered by the absence of relativistic effects as well as the numerical instabilities in some heavier elements. Finally, with further in-depth discussions, we generate possible directions for developing and improving FermiNet in the near future.
High transmission efficiency of intense sub-THz coherent phonons in strongly correlated VO2/TiO2 heterojunction
Authors: Wang Ziyue , Zhang Fan , Zhang Xiaoqiang , Liu Yongshan , Li Jiangxiao , Xu Yong , Zhang Yue , Hong Bin , Zhao Weisheng
Published: May 2024

High-frequency coherent acoustic phonons hold immense value in characterizing the coupling between magnetic, lattice, and electronic properties, offering nanometer-scale spatial resolution within the ultrafast timescale. However, efficiently propagating intense sub-THz coherent acoustic phonons across diverse materials remains a formidable challenge. Here, we demonstrate that using vanadium dioxide (VO2) as a transducer can induce enhanced coherent acoustic pulses that propagate efficiently (∼90%) into TiO2 due to excellent acoustic impedance matching and minor lattice interface mismatch compared with traditional metals such as Pt, Au, and Cu. Employing time-resolved pump–probe reflectivity spectroscopy, we observe pronounced coherent phonon oscillations reaching up to 0.164 THz from the longitudinal acoustic mode along the c axis in VO2/TiO2. Furthermore, the temperature and pump fluence dependence of the coherent phonon oscillation signals suggest that the metallic state of VO2 responds to these large coherent acoustic phonons.
Enhancing the circular dichroism of chiral dielectric nanostructure through the addition of a symmetric Au cylinder
Authors: Xi Feng , Hu Li , Dai Hongxia
Published: May 2024

Circular dichroism (CD) spectra play a crucial role in recognition, separation and detection of chiral molecules. Due to the inherent weak CD response of natural chiral molecules, researchers have endeavored to enhance CD signals through various artificial nanostructures. In this study, combining the advantages of both the dielectric and metal materials, we propose a hybrid dielectric-metal nanostructure consisting of a chiral Si nanorod dimer coupled with a symmetric Au cylinder to achieve robust CD responses. Owing to the plasmon resonance of the Au cylinder, the scattering-CD and absorption-CD of the hybrid system have been enhanced, which result in the enhanced extinction-CD response. Furthermore, the distributions of electric field, magnetic field and displacement current density of both the Si dimer and hybrid nanostructure have been meticulously crafted to elucidate the physical mechanisms underlying amplified CD signals. The synergistic coupling between the magnetic fields of dielectric materials and the electric fields of the Au cylinder leads to an increase in the electric field strength and the asymmetry of near-field distributions. Additionally, spatial overlaps between electric and magnetic fields occur. These factors contribute to the enhanced chiral response of the hybrid system. Meanwhile, the CD signal can be flexibly tuned by adjusting the size of the Au cylinder and Si nanorods. This design offers a versatile approach to enhancing the chiral response of dielectric nanostructures.
Bionic noise reduction design of axial fan impeller
Authors: Sun Yulong , Li Rui , Wang Linbo , Liu Chongrui , Yang Zhibo , Ma Fuyin
Published: May 2024

Fans are integral equipment widely employed in both industrial settings and daily life. However, a persistent challenge in fans design lies in the inherent conflict between aerodynamic performance and noise levels. Improving aerodynamic efficiency often results in a compromise of acoustic performance. To tackle this issue, we employed the bionic design method to craft a novel axial fan impeller featuring a bionic curved hub and bionic serrated leading edges. The impact of structural optimization on the aerodynamic and acoustic properties of the impeller, as well as the influence of optimization parameters on these properties, were systematically investigated through numerical simulations. The bionic impeller was then fabricated using 3D printing, and the aerodynamic and noise performance of the impeller were experimentally evaluated by integrating it into an external air conditioner. Comparison of the flow field and sound field data between the optimized and prototype impellers revealed noteworthy outcomes. The curved wall at the bionic hub’s tail effectively diminished the pressure gradient on the hub surface, directing the airflow toward the rear end of the hub. This design enhancement significantly reduced the turbulent area behind the prototype impeller’s hub. Additionally, under the appropriately designed, the bionic serrated structure could effectively reduce the contact area between the blade’s leading edge and incoming flow. This led to the dispersion of stress concentrations and the inhibition of strong turbulence generation. Notably, the experimental results indicated a 3.7% increase in air volume flow rate and a 2.3 dB reduction in noise for the optimized impeller compared to the prototype. This successful mitigation of the trade-off between aerodynamic performance and noise level underscores the effectiveness of our bionic design approach.
Prediction of single-layer antimony oxyselenide (Sb2O2Se2): metal-to-semiconductor transition via hydrogenation
Authors: Bozkurt Yagmur , Cetin Zebih , Yagmurcukardes Mehmet
Published: May 2024

In this study, the structural, electronic, vibrational, and mechanical properties of single-layer Antimony Oxyselenide (Sb2O2Se2) and its hydrogenated structure (Sb2O2Se2H2) are investigated by performing density functional theory-based first principles calculations. Geometry optimizations reveal that single-layer Sb2O2Se2 crystallizes in tetragonal structure which is shown to possess dynamical stability by means of phonon band dispersions. In addition, the mechanical stability of the predicted single layer is satisfied via the linear-elastic parameters. Electronically, it is revealed that single-layer Sb2O2Se2 exhibits metallic behavior whose highest occupied states are found to arise from the surface Se atoms, may be an indication for tuning the electronic features via surface functionalization. For the surface modification of Sb2O2Se2, top of each Se atom is saturated with a H atom and fully hydrogenated single-layer Sb2O2Se2H2 is shown to be an in-plane anisotropic structure. Phonon band dispersion calculations indicate the dynamical stability of Sb2O2Se2H2. Mechanically stable Sb2O2Se2H2 is found to possess anisotropic linear-elastic behavior, which is much softer than its pristine structure. Moreover, electronically a metallic-to-semiconducting transition is shown to occur as the unoccupied Se-orbitals are saturated via H atoms. Our work offers insights into prediction of a novel single-layer material, namely Sb2O2Se2, and reports the chemically-driven semiconducting behavior via hydrogenation, which may lead to the use of hydrogenated structure in solar cell, photoelectrode, or photocatalyst applications owing to its suitable band gap.
Research on dynamic balance optimization method of flexible rotor based on GWO
Authors: Zhang Fanyu , Li Xuejun , Han Qingkai , Guo Shuaiping , Han Shuo , Zhang Hongxian
Published: May 2024

Aiming at the problem that the dynamic balance process of a flexible rotor needs to start and stop frequently to add test weight, which is time-consuming and labor-consuming, and the balance accuracy is difficult to guarantee, a dynamic balance optimization method of flexible rotor based on grey wolf optimizer (GWO) is proposed. In this paper, a virtual prototype model is established based on a power turbine rotor for a certain type of turboshaft engine, and a rotor test platform is built. The transfer function is used to find the relationship between unbalance and vibration response, and the equilibrium equations are established to solve the problem. In the process of solving the problem that the equilibrium equations are mostly contradictory, GWO is used to solve the contradictory equations to obtain the optimal counterweight scheme at the full working speed of the rotor. The results show that the method proposed in this paper eliminates the cumbersome trial weight process of traditional dynamic balance. The average vibration reduction rate of this method is 33.8% at 5100 r min−1, 5400 r min−1 and 5700 r min−1, which is better than the conventional field dynamic balance. The work of this paper can improve the efficiency and accuracy of flexible rotor dynamic balance and provide technical reference for the vibration control of aero-engine.
Essential oil mediated synthesis and application of highly stable copper nanoparticles as coatings on textiles and surfaces for rapid and sustained disinfection of microorganisms
Authors: Nag Pooja , Sadani Kapil , Pisharody Lakshmi , Thian Xiao Yun , Ratnakar Tadi Sai , Ansari Arhama , Mukherji Suparna , Mukherji Soumyo
Published: May 2024

Rampant pathogenesis induced by communicable microbes has necessitated development of technologies for rapid and sustained disinfection of surfaces. Copper nanoparticles (CuNPs) have been widely reported for their antimicrobial properties. However, nanostructured copper is prone to oxidative dissolution in the oil phase limiting its sustained use on surfaces and coatings. The current study reports a systematic investigation of a simple synthesis protocol using fatty acid stabilizers (particularly essential oils) for synthesis of copper nanoparticles in the oil phase. Of the various formulations synthesized, rosemary oil stabilized copper nanoparticles (RMO CuNPs) were noted to have the best inactivation kinetics and were also most stable. Upon morphological characterization by TEM and EELS, these were found to be monodispersed (φ 5–8 nm) with copper coexisting in all three oxidation states on the surface of the nanoparticles. The nanoparticles were drop cast on woven fabric of around 500 threads per inch and exposed to gram positive bacteria (Staphylococcus aureus), gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa), enveloped RNA virus (phi6), non-enveloped RNA virus (MS2) and non-enveloped DNA virus (T4) to encompass the commonly encountered groups of pathogens. It was possible to completely disinfect 107 copies of all microorganisms within 40 min of exposure. Further, this formulation was incorporated with polyurethane as thinners and used to coat non-woven fabrics. These also exhibited antimicrobial properties. Sustained disinfection with less than 9% cumulative copper loss for upto 14 washes with soap water was observed while the antioxidant activity was also preserved. Based on the studies conducted, RMO CuNP in oil phase was found to have excellent potential of integration on surface coatings, paints and polymers for rapid and sustained disinfection of microbes on surfaces.
Graphite/h-BN van der Waals heterostructure as a gate stack for HgTe quantum wells
Authors: Liang Xianhu , Shamim Saquib , Chen Dongyun , Fürst Lena , Taniguchi Takashi , Watanabe Kenji , Buhmann Hartmut , Kleinlein Johannes , Molenkamp Laurens W
Published: May 2024

Two-dimensional topological insulators have attracted much interest due to their potential applications in spintronics and quantum computing. To access the exotic physical phenomena, a gate electric field is required to tune the Fermi level into the bulk band gap. Hexagonal boron nitride (h-BN) is a promising alternative gate dielectric due to its unique advantages such as flat and charge-free surface. Here we present a h-BN/graphite van der Waals heterostructure as a top gate on HgTe heterostructure-based Hall bar devices. We compare our results to devices with h-BN/Ti/Au and HfO2/Ti/Au gates. Devices with a h-BN/graphite gate show no charge carrier density shift compared to as-grown structures, in contrast to a significant n-type carrier density increase for HfO2/Ti/Au. We attribute this observation mainly to the comparable work function of HgTe and graphite. In addition, devices with h-BN gate dielectric show slightly higher electron mobility compared to HfO2-based devices. Our results demonstrate the compatibility between layered materials transfer and wet-etched structures and provide a strategy to solve the issue of significant shifts of the carrier density in gated HgTe heterostructures.
Enhancing the acidic oxygen evolution reaction performance of RuO2-TiO2 by a reduction-oxidation process
Authors: Zhang Jianjun , Song Yi , Liu Wenwei , Zheng Quan , Liu Yu , Wu Tianli , Li Tao
Published: May 2024

As a promising alternative to Ir based acidic oxygen evolution reaction (OER) catalysts, Ru suffers from severe fading issues. Supporting it on robust oxides such as TiO2 is a simple and effective way to enhance its lifetime. Here, we find that a simple reduction-oxidation process can further improve both activity and stability of RuO2-TiO2 composites at high potentials. In this process, the degree of oxidation was carefully controlled to form Ru/RuO2 heterostructure to improve OER activity. Moreover, due to the oxophilicity difference of Ru and Ti, the structure of catalysts was changed from supported to embedded, which enhanced the protective effect of TiO2 and mitigated the dissolution of Ru element in acidic electrolyte, making as-prepared Ru/RuO2-TiO2 with better durability at all tested potentials.
Ginzburg–Landau equation with fractional Laplacian on a upper- right quarter plane
Authors: Carreño-Diaz J F , Kaikina E I
Published: May 2024

We consider the initial-boundary value problem for the Ginzburg–Landau equation with fractional Laplacian on a upper-right quarter plane

{

u

t

(
t
,

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)

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,

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where

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,

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∈

(

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and

∇

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is a fractional Laplacian defined as

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=

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j

1

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(
2
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)

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0

x

j

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.

We study the main questions of the theory of IBV- problems for nonlocal equations: the existence and uniqueness of a solution, the asymptotic behavior of the solution for large time and the influence of initial and boundary data on the basic properties of the solution. We generalize the concept of the well-posedness of IBV- problem in the

L

2

−

based Sobolev spaces to the case of a multidimensional domain. We also give optimal relations between the orders of the Sobolev spaces to which the initial and boundary data belong. The lower order compatibility conditions between initial and boundary data are also discussed.
Effect of rapid thermal annealing on DC performance of Mg0.30Zn0.70O/Cd0.15Zn0.85O MOSHFET
Authors: Kumar Pawan , Mahapatra Brahmadutta , Chaudhary Sumit , Ako Rajour Tanyi , Sriram Sharath , Mukherjee Shaibal
Published: May 2024

This study focuses on a cost-effective method for fabrication of a metal oxide semiconductor-heterostructure field effect transistor (MOSHFET) based on MgZnO/CdZnO (MCO) using dual ion beam sputtering (DIBS), in contrast to the more expensive epitaxial growth system. The MOSHFETs developed in this research exhibit notable characteristics, such as a substantial two-dimensional electron gas (2DEG) transconductance (∼2.6 mS), a high ION/IOFF response ratio in the order of 108, and minimal gate leakage current. Furthermore, we explore the impact of rapid thermal annealing (RTA) on the drain current at various temperatures (600 °C and 800 °C). The results indicate a fourfold improvement in drain current compared to unannealed conditions, primarily attributed to reduced contact resistance and no degradation in term of MgZnO/CdZnO structure. Additionally, an analysis of post-RTA treatment under a nitrogen (N2) atmosphere on gate leakage current is presented. The investigation spans temperatures ranging from 400 °C to 800 °C, revealing that above 600 °C (gate leakage at 400 °C–600 °C is around ∼10−9 A), gate leakage in HFET is augmented by one order of magnitude (∼10−8 A) due to a phase change in the dielectric. These findings underscore the feasibility of DIBS-grown MCO MOSHFETs as an economical solution for the mass production of switching devices and sensors.
Exploration and optimization of novel replacement and prefetching strategies for inefficiencies of advanced MRAM-based hybrid cache systems
Authors: Han Shaopu , Jiang Yanfeng
Published: May 2024

With the emergence of cutting-edge hardware systems such as cloud computing, edge computing, and on-chip neural network accelerators, how to design advanced memory strategies to substitute the traditional ones for maximizing the potential performance of non-volatile memory (NVM) under the existing hardware conditions, has become an urgent research issue for both academia and industrial communities. It is promising and innovative to improve computer systems in the layer of data exchanging with the emerging advanced semiconductor devices. In the paper, to address the inefficiencies of write-intensive, high power consumption, low hit rate and so on, which exist in hybrid magnetic random access memory cache systems, three novel cache replacement strategies and two cache prefetching strategies are put forward. The proposed triple novel replacement strategies, including historical frequency and time judgments, duplicate data-aware deletion, and dynamic relevance factors computing, can be utilized to compensate for the shortcomings of the traditional least recently used replacement strategy, respectively. In the two novel prefetching strategies, region distribution parameters and Listnet ranking network are imported into the caching process, respectively, to achieve optimized hitting performance. The simulation results demonstrate that the proposed replacement strategies can achieve up to 61.76%, 84.91%, 56.49%, and 53.21% optimization of write count, hit rate, dynamic power, and IPC compared to the conventional one. The proposed prefetching strategy can achieve up to 91.27%, 49.25% hit rate and IPC optimization. Meanwhile, the synthetic evaluation of the replacement and prefetching strategies are elaborated in the paper, including multi-core characteristics, information entropy, interplays and the performance constraints between replacement and prefetching mechanism, which would facilitate more credible ideas for future memory inefficiencies management and strategy design.
Auxetic hybrid metamaterial with tunable elastic wave bandgap
Authors: Chen Gui Lei , Tao Zhi , Luo Yu Ming , Zhang Yi , Pan Yang , Han Dong , Ma Fu Yin , Zhu Rui , Ren Xin
Published: May 2024

Auxetic metamaterials have shown good stability and uniform deformation capabilities against influences (vibration, temperature change, load change), making them significant in maintaining and adjusting the bandgap of phonon crystals. The low-frequency and broadband are the important goals of phonon crystals. For most traditional re-entrant honeycomb structures (T-RHS), the bandgap range is narrow and tunability is poor. Here, an auxetic hybrid structure with tunable acoustic bandgap (AHS-T) consisting of periodic mass inclusions integrated with traditional re-entrant honeycomb and chiral hybrid is proposed. Aiming at investigating the tunability of the bandgap in the low-frequency range. Compared with T-RHS, the bandgap real-time adjustment and wider bandwidth of the AHS-T be realized during compression and tension. The numerical results show that the bandgap of the AHS-T can be flexibly tailored by reasonably adjusting the strain and geometrical configurations of AHS-T. The bandwidth of AHS-T can be increased to 87.1% when the bottom diameter

D
b

and column height H of the scatterer are changed reasonably. Moreover, the deformation behavior of auxetic material has an auxiliary effect on expanding the bandwidth. Compared with the structure which is not subjected to load, the adjustable amplitude of the bandgap is 41%. The findings of this work provide a design idea for manipulating elastic waves in dynamic environment.
Analytical solutions to the Euler equations for Chaplygin gas
Authors: Jiang Hongjing , Dong Jianwei
Published: May 2024

In this paper, we study the analytical solutions to the Euler equations for Chaplygin gas. First, we construct two exact solutions for the one-dimensional system by using a self-similar ansatz. Second, we present some analytical solutions for the N-dimensional radially symmetric system. Third, we extend the above results to the two-phase flow case. The concentration and cavitation phenomena are observed from the constructed solutions.
Extending Finch-Skea isotropic model to anisotropic domain in modified f(,

T

) gravity
Authors: Naseer Tayyab , Sharif M
Published: May 2024

This paper considers the Finch-Skea isotropic solution and extends its domain to three different anisotropic interiors by using the gravitational decoupling strategy in the context of

f
(
R
,
T
)

gravitational theory. For this, we consider that a static spherical spacetime is initially coupled with the perfect matter distribution. We then introduce a Lagrangian corresponding to a new gravitating source by keeping in mind that this new source produces the effect of pressure anisotropy in the parent fluid source. After calculating the field equations for the total matter setup, we apply a transformation on the radial component, ultimately providing two different systems of equations. These two sets are solved independently through different constraints that lead to some new solutions. Further, we consider an exterior spacetime to calculate three constants engaged in the seed Finch-Skea solution at the spherical interface. The estimated radius and mass of a star candidate LMC X-4 are utilized to perform the graphical analysis of the developed models. It is concluded that only the first two resulting models are physically relevant in this modified theory for all the considered parametric choices.
Strain-tunable electronic structure, optical and thermoelectric properties of BAs
Authors: Yu Heng , Li Yi , Wei Dong , Guo Gaofu , Feng Zhen , Ma Yaqiang , Tang Yanan , Dai Xianqi
Published: May 2024

Strain engineering stands as a reliable method for tailoring the physicochemical properties of materials to achieve desired performance. However, the effects of strain on the physicochemical properties of BAs remain unclear, impeding the comprehensive understanding of its practical performance. Here, employing first-principles calculations coupled with semiclassical Boltzmann transport theory, we investigate the dynamic stability, mechanical stability, electronic structure, and thermoelectric properties of cubic boron arsenide (BAs) under various strains. The results demonstrate that BAs maintains excellent stability throughout the triaxial strain range. The electronic structure of BAs is less affected by strain. Young’s modulus and Poisson’s ratio show a corresponding linear increase when the compression strain increases. The optical absorption coefficient in the visible region of BAs under tensile strain showed an overall increasing trend, and the optical absorption coefficient in the visible wavelength region of BAs under 5% tensile strain was as high as 2 × 105 cm−1. The thermoelectric properties of BAs under tensile strain have been improved, and the ZT value of BAs under 5% tensile strain at 1500 K has been increased to 0.6. The research findings address the gaps in understanding the properties of BAs under strain and provide theoretical support for its applications in the fields of thermoelectrics and optoelectronics.
Dynamical analysis of a novel memristor-type chaotic map
Authors: Yu Xiong , Abu Bakar Azuraliza , Li Kunshuai , Wang Qiao , Sang Haiwei
Published: May 2024

As a unique nonlinear component, the discrete memristor, with its simple structure, is associated with the ability to lead to excellent chaotic performance in the construction of chaotic systems. This characteristic has elevated the discrete memristor to a hot topic in the field of chaos. This paper introduces a cosine hyperchaotic map. Numerical simulations reveal its rich dynamical behaviors. The chaotic map exhibits diverse chaotic control models, including partial amplitude control, total amplitude control, initial boosting, and parameter-offset boosting, with dynamical distribution diagrams plotted for amplitude control to quantify the range of amplitude modulation. Additionally, a localized boosting free region is identified, which exhibits extreme sensitivity to initial values. Dual offset parameters are introduced to control this localized boosting free region, enhancing the flexibility of the system. Finally, the map is implemented on STM32 to validate the numerical simulation results.
Rotating target detection model under arbitrary incidence of the vortex beam based on optical RDE
Authors: Ma ShengJie , Xu ShiLong , Zhang XinYuan , Chen YouLong , Dou ZhengLei , Hu YiHua
Published: May 2024

The optical rotational Doppler effect (RDE) related to orbital angular momentum has attracted extensive attention in rotating targets detection. In this paper, we present a novel rotating target detection model based on optical RDE, where the vortex beam can be incident on the rotating target with an arbitrary case. Based on the proposed detection model, we investigated the mechanism of rotational Doppler shift and deduced the generalized formula of the Doppler frequency shift under arbitrary incidence of the vortex beam by phase modulation method. Subsequently, the model is studied under different incident cases, and the variation of Doppler frequency shift with different incident parameters is analyzed combining with the deduced formulas. Meanwhile, we also give the detection methods to for motion parameter estimations of the rotating target. Theoretical and simulated results verify the effectiveness of the proposed model, and more detailed motion parameters can be obtained based on RDE. This theoretical model enables us to better understand the generation of the rotational Doppler frequency and may be useful for the application of remote sensing of a rotating target.
Effect of thickness on properties of La-doped Zinc Blende/Wurtzite ZnO thin films prepared by spray pyrolysis
Authors: Aboud Ahmed A , Al-Harbi Najah F , Mostafa Khlifa Moatasem , Mukherjee Ayan
Published: May 2024

Thin films of ZnO doped with 3 wt% Lanthanum were deposited on glass substrates using spray pyrolysis for varying thicknesses. The impact of thickness on the physical properties of the films was investigated using various techniques. XRD results revealed the formation of a mixture of two phases, cubic Zinc Blende (ZB) and hexagonal Wurtzite (WU), with their ratios changing based on film thickness. Crystallite size measurements indicated that the cubic phase granules remained stable at 14.6 nm up to a thickness of 719 nm, decreasing to 14 nm at 846 nm, while the crystallite size of the hexagonal phase increased to 18 nm at 846 nm. FE-SEM images showed changes in surface morphology with increasing thickness, and EDX analysis demonstrated a consistent La/Zn ratio across all film thicknesses. The refractive index exhibited a shift from normal to abnormal dispersion when the thickness exceeded 719 nm, and the high-frequency dielectric constant decreased from 3.2 to 2.91 as the thickness increased. Additionally, optical band gaps ranged from a minimum of 3.19 eV at 719 nm thickness to a maximum of 3.23 eV at 846 nm thickness. The study examined the effectiveness of the deposited films in blocking UV light with a wavelength of 365 nm. It was discovered that the decay time significantly decreased to 143 s at a thickness of 661 nm, compared to longer times observed at other thicknesses.
Topological rainbow trapping of shear horizontal waves in a phononic crystal plate with tapered surface
Authors: Bu Xiangzhen , Huang Hongbo , Chen Jiujiu
Published: May 2024

Topological interface states have localized field enhancement characteristics. Integrating them with the concept of rainbow trapping undoubtedly be a more effective method for elastic energy localization and collection. In this paper, the tunable interface state of shear horizontal (SH) waves is realized in a one-dimensional (1D) phononic crystal (PC) plate by modifying the structural parameters of unit cells with tapered surfaces, where the interface state emerges in the overlapping band gaps of two types of unit cells with different Zak phases. Furthermore, we assembled seven types of unit cells with gradient variations, achieving topological rainbow trapping. Meanwhile, the robustness of the rainbow state has been demonstrated, and more separated frequencies are obtained by changing the order of these unit cells. The results of the study demonstrate that the highly localized, compact, and broadband tunable topological rainbow system we designed holds promise for applications in areas such as elastic energy harvesting, filtering, and multi-frequency signal processing.
A modified perturbation method for global dynamic analysis of generalized mixed Rayleigh–Liénard oscillator with cubic and quintic nonlinearities
Authors: Li Zhenbo , Hou Linxia , Zhang Yiqing , Xu Feng
Published: May 2024

Deriving analytical relationship between the system parameters and amplitude of the limit cycle is a meaningful and challenging task. Currently, numerous existing analytical approximate methods struggle to achieve this goal when expressions of restoring force or nonlinear damping is complicated. To overcome this shortcoming, this study proposes a modified generalized harmonic function perturbation method. Using the proposed method, a generalized mixed RayleighLiénard oscillator with cubic and quintic nonlinearities was investigated. The analytical relationships between the system parameters and amplitude of the limit cycle, as well as the expression of its characteristic quantity, were derived. By employing these analytical relationships, the existence, stability, number, position, and amplitude of each limit cycle are quantitatively analysed. The homoclinic and heteroclinic bifurcations were also predicted using the above analytical relationships. Additionally, analytical approximate solutions for this oscillator were calculated using the proposed method. All results obtained in this study were subsequently confirmed numerically to demonstrate their feasibility and validity. Consequently, the proposed method can be considered an effective supplement to perturbation-based methods. This also implies that the work presented in this paper has a certain theoretical significance and application value in the research area of quantitative analysis methods for strongly nonlinear oscillators.
Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO2 thin films
Authors: Chen 陈 S X 思学 , Chen 陈 M M 明明 , Liu 刘 Y 圆 , Cao 曹 D W 大威 , Chen 陈 G J 国杰
Published: May 2024

Ferroelectric HfO2 has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal–oxide–semiconductor (CMOS) technology. However, the crystallization of polar orthorhombic phase (o-phase) HfO2 is less competitive, which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO2 thin films. Fortunately, the crystallization of o-phase HfO2 can be thermodynamically modulated via interfacial stress engineering. In this paper, the growth of improved ferroelectric Al doped HfO2 (HfO2:Al) thin films on (111)-oriented Si substrate has been reported. Structural analysis has suggested that nonpolar monoclinic HfO2:Al grown on (111)-oriented Si substrate suffered from a strong compressive strain, which promoted the crystallization of (111)-oriented o-phase HfO2 in the as-grown HfO2:Al thin films. In addition, the in-plane lattice of (111)-oriented Si substrate matches well with that of (111)-oriented o-phase HfO2, which further thermally stabilizes the o-phase HfO2. Accordingly, an improved ferroelectricity with a remnant polarization (2P
r) of 26.7 μC/cm2 has been obtained. The results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO2 thin films.
Frequency combs based on magnon-skyrmion interaction in magnetic nanotubes
Authors: Abdulrazak Tijjani , Liu 刘 Xuejuan 雪娟 , Jin 金 Zhejunyu 哲珺雨 , Cao 曹 Yunshan 云姗 , Yan 严 Peng 鹏
Published: May 2024

Within the magnonics community, there has been a lot of interests in the magnon–skyrmion interaction. Magnons and skyrmions are two intriguing phenomena in condensed matter physics, and magnetic nanotubes have emerged as a suitable platform to study their complex interactions. We show that magnon frequency combs can be induced in magnetic nanotubes by three-wave mixing between the propagating magnons and skyrmion. This study enriches our fundamental comprehension of magnon–skyrmion interactions and holds promise for developing innovative spintronic devices and applications. This frequency comb tunability and unique spectral features offer a rich platform for exploring novel avenues in magnetic nanotechnology.
Nonlinear time-reversal interferometry with arbitrary quadratic collective-spin interaction
Authors: Hu 胡 Zhiyao 知遥 , Li 李 Qixian 其贤 , Zhang 张 Xuanchen 轩晨 , Zhang 张 He-Bin 贺宾 , Huang 黄 Long-Gang 龙刚 , Liu 刘 Yong-Chun 永椿
Published: May 2024

Atomic nonlinear interferometry has wide applications in quantum metrology and quantum information science. Here we propose a nonlinear time-reversal interferometry scheme with high robustness and metrological gain based on the spin squeezing generated by arbitrary quadratic collective-spin interaction, which could be described by the Lipkin–Meshkov–Glick (LMG) model. We optimize the squeezing process, encoding process, and anti-squeezing process, finding that the two particular cases of the LMG model, one-axis twisting and two-axis twisting outperform in robustness and precision, respectively. Moreover, we propose a Floquet driving method to realize equivalent time reverse in the atomic system, which leads to high performance in precision, robustness, and operability. Our study sets a benchmark for achieving high precision and high robustness in atomic nonlinear interferometry.
Three-dimensional crystal defect imaging by STEM depth sectioning
Authors: Ishikawa Ryo , Shibata Naoya , Ikuhara Yuichi
Published: May 2024

One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic resolution. Despite the success of aberration correction to deep sub-ångström lateral resolution, spatial resolution in depth is still far from atomic resolution. In scanning transmission electron microscopy (STEM), this poor depth resolution is due to the limitation of the illumination angle. To overcome this physical limitation, it is essential to implement a next-generation aberration corrector in STEM that can significantly improve the depth resolution. This review discusses the capability of depth sectioning for three-dimensional imaging combined with large-angle illumination STEM. Furthermore, the statistical analysis approach remarkably improves the depth resolution, making it possible to achieve three-dimensional atomic resolution imaging at oxide surfaces. We will also discuss the future prospects of three-dimensional imaging at atomic resolution by STEM depth sectioning.
Two-fold symmetry of the in-plane resistance in kagome superconductor Cs(V1–xTax)3Sb5 with enhanced superconductivity
Authors: Zhao 赵 Zhen 振 , Wang 王 Ruwen 汝文 , Zhang 张 Yuhang 宇航 , Zhu 祝 Ke 轲 , Yu 余 Weiqi 维琪 , Han 韩 Yechao 烨超 , Liu 刘 Jiali 家利 , Hu 胡 Guojing 国静 , Guo 郭 Hui 辉 , Lin 林 Xiao 晓 , Dong 董 Xiaoli 晓莉 , Chen 陈 Hui 辉 , Yang 杨 Haitao 海涛 , Gao 高 Hong-Jun 鸿钧
Published: May 2024

The kagome superconductor CsV3Sb5 has attracted widespread attention due to its rich correlated electron states including superconductivity, charge density wave (CDW), nematicity, and pair density wave. Notably, the modulation of the intertwined electronic orders by the chemical doping is significant to illuminate the cooperation/competition between multiple phases in kagome superconductors. In this study, we have synthesized a series of tantalum-substituted Cs(V1−x
Ta
x
)3Sb5 by a modified self-flux method. Electrical transport measurements reveal that CDW is suppressed gradually and becomes undetectable as the doping content of x is over 0.07. Concurrently, the superconductivity is enhanced monotonically from T
c ∼ 2.8 K at x = 0 to 5.2 K at x = 0.12. Intriguingly, in the absence of CDW, Cs(V1−x
Ta
x
)3Sb5 (x = 0.12) crystals exhibit a pronounced two-fold symmetry of the in-plane angular-dependent magnetoresistance (AMR) in the superconducting state, indicating the anisotropic superconducting properties in the Cs(V1−x
Ta
x
)3Sb5. Our findings demonstrate that Cs(V1−x
Ta
x
)3Sb5 with the non-trivial band topology is an excellent platform to explore the superconductivity mechanism and intertwined electronic orders in quantum materials.