bluuebunny/crossref_metadata_2025 huggingface dataset:
Using SOR framework to explore the driving factors of older adults smartphone use behavior
Authors: Huang Tianyang
Published: October 2023

At a time when the population is aging and the digital divide among older adults is becoming increasingly prominent, the research on the smartphone use behavior of the older adult in China is slightly insufficient. Therefore, this study aims to develop a smartphone acceptance model for older adults in China to predict the factors of their behavioral intention to use smartphones. Using Stimulus-organism-response (SOR) theory as the framework, planned behavior theory, self-efficacy theory and technology acceptance model as the theoretical basis, and employed a mixed quantitative and qualitative research approach to analyze the data from 244 older adults using structural equation modeling. The results show that technology anxiety, subjective norms, self-efficacy, perceived usefulness, facilitating conditions, and perceived ease of use had significant effects on the behavioral intention smartphones among older adults. In addition, perceived usefulness was directly influenced by subjective norms and perceived ease of use, facilitating conditions significantly influenced perceived ease of use and self-efficacy, and subjective norms and self-efficacy significantly affect technology anxiety. This study expanded the applicability of SOR framework, further expanded the technology acceptance model, and enriched the theory of smart phone use behavior of older adults users. The results of this study provide a valuable theoretical framework for the study on older adults users’ behaviors and have implications for the design and marketing of smartphones with high acceptancy from older adults.
Low threshold room-temperature lasing emission from high-crystalline ZnS nanowires and nanobelts
Authors: Tran M. T. , Trung D. Q. , Du N. V. , Tu N. , Hieu N. M. , Ha N. N. , Hung N. D. , Viet D. X. , Quang N. V. , Huy P. T.
Published: October 2023

ZnS nanostructures possess exceptional features, making them highly promising as gain media and optical waveguides for nanolasers and optoelectronic devices. These features include low lasing thresholds and effortless fabrication. In this study, we present high-crystalline ZnS nanowires (NWs) and nanobelts (NBs) synthesized by using a thermal evaporation route. The remarkably low lasing thresholds of 45.3–45.5 W/cm2 are achieved at room temperature, marking a two-orders-of-magnitude improvement over reported values for ZnS nanostructures. Comprehensive analysis, incorporating techniques such as x-ray diffraction, Raman spectra, transmission electron microscopy, x-ray photoelectron spectroscopy, and photoluminescence, confirms the great quality of the synthesized nanostructures. The excitonic lasing emissions from ZnS NWs and NBs exhibit small full width at half maximum values of 5.9 and 0.53 nm, respectively. These emissions occur within cavities measuring ∼5.1 to 5.6 μm, with high-quality factors (112.6 for ZnS NWs and 598.6 for ZnS NBs), further highlighting the excellent performance of the materials. Moreover, the gain factors of 17.32–26.63 underscore the significant potential of ZnS NWs and NBs as prime candidates for ultraviolet photonic devices.
Singular perturbation analysis in a coupled Chua’s circuit with diffusion
Authors: Li Zhengkang , Liu Xingbo
Published: October 2023

This paper is concerned with the traveling wave solutions of a singularly perturbed system, which arises from the coupled arrays of Chua’s circuit. By the geometric singular perturbation theory and invariant manifold theory, we prove that there exists a heteroclinic cycle consisting of the traveling front and back waves with the same wave speed. In particular, the expression of corresponding wave speed is also obtained. Furthermore, we show that the chaotic behavior induced by this heteroclinic cycle is hyperchaos.
Distributed inertial online game algorithm for tracking generalized Nash equilibria
Authors: Bai Haomin , Xu Wenying , Yang Shaofu , Cao Jinde
Published: October 2023

This paper is concerned with the distributed generalized Nash equilibrium (GNE) tracking problem of noncooperative games in dynamic environments, where the cost function and/or the coupled constraint function are time-varying and revealed to each agent after it makes a decision. We first consider the case without coupled constraints and propose a distributed inertial online game (D-IOG) algorithm based on the mirror descent method. The proposed algorithm is capable of tracking Nash equilibrium (NE) through a time-varying communication graph and has the potential of achieving a low average regret. With an appropriate non-increasing stepsize sequence and an inertial parameter, the regrets can grow sublinearly if the deviation of the NE sequence grows sublinearly. Second, the time-varying coupled constraints are further investigated, and a modified D-IOG algorithm for tracking GNE is proposed based on the primal-dual and mirror descent methods. Then, the upper bounds of regrets and constraint violation are derived. Moreover, inertia and two information transmission modes are discussed. Finally, two simulation examples are provided to illustrate the effectiveness of the D-IOG algorithms.
Impact of Allee and fear effects in a fractional order prey–predator system with group defense and prey refuge
Authors: Tan Wenhui , Tian Hao , Song Yanjie , Duan Xiaojun
Published: October 2023

This paper presents a novel fractional-order model of a prey–predator system that incorporates group defense and prey refuge mechanisms, along with Allee and fear effects. First, we examine the existence, uniqueness, non-negativity, and boundedness of the solution of the system. Second, a comprehensive analysis is conducted on the existence, stability, and coexistence of equilibrium states in the system, which are crucial for comprehending prey–predator system behavior. Our investigation reveals that the coexistence equilibrium undergoes a Hopf bifurcation under five key parameters. Specifically, an increased threshold for the transition between group and individual behavior, influenced by different strengths of the Allee effect, enhances the stability of both populations. This discovery sheds light on the role of group effects in shaping prey–predator interactions and ecosystem stability. Third, system discretization is employed to explore the impact of step size on stimulating stability and to investigate the Neimark–Sacker bifurcation, providing a more comprehensive understanding of system behavior. The role of step size as a constraint on stability is examined, revealing the system’s progression from stability to chaos. Consequently, our results offer a more flexible mechanism for adjusting the stability and dynamics of the two species. Finally, numerical simulations are utilized to validate the reasonableness of the research findings.
Positive solutions for a non-autonomous Schrödinger-Bopp-Podolsky system
Authors: Liu Jiu , Duan Yu , Liao Jia-Feng , Pan Hui-Lan
Published: October 2023

In the paper, by using the variational methods we study a non-autonomous Schrödinger-Bopp-Podolsky system, where a > 0, 3 < p < 4 are fixed, λ > 0 is a parameter, and the potentials V, Q satisfy appropriate assumptions. We give some existence results, depending on the parameter λ. Moreover the results are still valid for the classical Schrödinger-Poisson system.
Online data-driven changepoint detection for high-dimensional dynamical systems
Authors: Lin Sen , Mengaldo Gianmarco , Maulik Romit
Published: October 2023

The detection of anomalies or transitions in complex dynamical systems is of critical importance to various applications. In this study, we propose the use of machine learning to detect changepoints for high-dimensional dynamical systems. Here, changepoints indicate instances in time when the underlying dynamical system has a fundamentally different characteristic—which may be due to a change in the model parameters or due to intermittent phenomena arising from the same model. We propose two complementary approaches to achieve this, with the first devised using arguments from probabilistic unsupervised learning and the latter devised using supervised deep learning. To accelerate the deployment of transition detection algorithms in high-dimensional dynamical systems, we introduce dimensionality reduction techniques. Our experiments demonstrate that transitions can be detected efficiently, in real-time, for the two-dimensional forced Kolmogorov flow and the Rössler dynamical system, which are characterized by anomalous regimes in phase space where dynamics are perturbed off the attractor at potentially uneven intervals. Finally, we also demonstrate how variations in the frequency of detected changepoints may be utilized to detect a significant modification to the underlying model parameters by utilizing the Lorenz-63 dynamical system.
Electric field-controlled deterministic magnetization reversal in nanomagnet Fe3Si/PMN-PT multiferroic heterostructures
Authors: Su Zheng , Guo Xiao-Bin , Qiu Wen-Hai , He Ang , Li Wen-Hua , Jiang Yan-Ping , Li Shui-Feng , Tang Xin-Gui
Published: October 2023

Pure electric field-controlled 180° magnetization switching plays a vital role in low-power magnetoelectric memory devices. Using micromagnetic simulation, we engineered a square-shaped epitaxial Fe3Si nanomagnet on a PMN-PT piezoelectric substrate to make the magnetic easy axis slightly deviate 18° from the piezostrain axis, aiming to break the symmetry of the magnetization distribution and achieve deterministic magnetization reversal paths. Under the coaction of a magnetic field and an electric field, the simulated magnetic hysteresis loops and magnetic domain patterns reveal a fourfold to twofold magnetic anisotropy transition and magnetization reversal paths. Stimulated by pure electric field-induced piezoelectric strain, deterministic 180° magnetization reversals are accomplished by the two successive clockwise 90° switching process. The results help to comprehend electrically regulated deterministic magnetization reversal and pave an avenue for designing multistate spintronics devices.
Flexible metasurfaces as sub-6 GHz frequency selective surfaces for 5G applications
Authors: Materón E. M. , Filgueiras H. R. D. , Vilas Boas E. C. , Gómez F. R. , Cavalcanti F. R. P. , Silva Y. C. B. , Cerqueira S. Arismar , de Figueiredo F. A. P. , Mendes L. L. , Oliveira Osvaldo N. , Mejía-Salazar J. R.
Published: October 2023

The deployment of fifth-generation mobile network (5G), beyond 5G and sixth-generation mobile network platforms encounters challenges of blockage, interference, and path loss in radio mobile environments. Metasurfaces provide a promising solution to address these limitations. In this paper, we present a methodology for developing ultrathin flexible metasurface-based frequency selective surfaces (FSSs). Our approach combines thermal evaporation for metallic thin films with a macroscopic metasurface mask (something analogous to screen-printing but using thermal evaporation instead of inks). As a proof of concept, we fabricate a sub-6 GHz metasurface-based FSS using gold deposition on a flexible polyethylene terephthalate substrate. Experimental results are validated through numerical full-wave simulations using COMSOL Multiphysics and equivalent-circuit model simulations. The metasurface operates within the primary frequency band utilized in 5G networks (3–5 GHz), indicating its potential applicability across a wide range of flexible, conformal, and wearable devices. The fabricated FSS can be installed on surfaces of any shape, such as flat or curved windows, as well as on walls or other external surfaces. This methodology offers practical solutions for wireless communications and enhancing signal transmission in diverse environments.
High-stability quinary lead-based piezoelectric ceramics with high piezoelectric properties
Authors: He Xingchen , Lu Yuanhao , Chu Tao , Liao Wenyong , Li Tao , Liu Xiaoli , Liang Lianyao , Li Huayong , Dai Xingyu , Liu Ying , Zhou Liujiang
Published: October 2023

Piezoceramics with the formula Pb0.93Sr0.06Ba0.01(Mg1/3Nb2/3)0.035(Ni1/3Nb2/3)0.2 (Sb1/2Nb1/2)0.015(ZrxTi1−x)0.75O3 + 0.5 wt. % Li2CO3, where x = 0.51, 0.50, 0.49, 0.48, 0.47, and 0.46, have been made using the one-step solid-state method. The phase structure and electrical properties were systematically investigated in the quinary system. Here, the crystalline structure transformed gradually from the rhombohedral to tetragonal phase with decreasing Zr content. More importantly, the effective piezoelectric coefficient d33* of the ceramics demonstrates an excellent thermal stability below the Curie temperature. Meanwhile, piezoelectric ceramics with x = 0.49 exhibited the extraordinary electrical properties near the morphotropic phase boundary. A huge piezoelectric coefficient d33 = 853 pC/N, high Curie temperature TC = 152 °C, and the electromechanical coupling coefficients kp = 67.4%, kt = 63.5%, and k33 = 67.4% were obtained at the composition of x = 0.49, which may lead a promising future for the transducer applications.
Nanoscale domain engineering in SrRuO3 thin films
Authors: Lichtensteiger Céline , Su Chia-Ping , Gaponenko Iaroslav , Hadjimichael Marios , Tovaglieri Ludovica , Paruch Patrycja , Gloter Alexandre , Triscone Jean-Marc
Published: October 2023

We investigate nanoscale domain engineering via epitaxial coupling in a set of SrRuO3/PbTiO3/SrRuO3 heterostructures epitaxially grown on (110)o-oriented DyScO3 substrates. The SrRuO3 layer thickness is kept at 55 unit cells, whereas the PbTiO3 layer is grown to thicknesses of 23, 45, and 90 unit cells. Through a combination of atomic force microscopy, x-ray diffraction, and high resolution scanning transmission electron microscopy studies, we find that above a certain critical thickness of the ferroelectric layer, the large structural distortions associated with the ferroelastic domains propagate through the top SrRuO3 layer, locally modifying the orientation of the orthorhombic SrRuO3 and creating a modulated structure that extends beyond the ferroelectric layer boundaries.
Physical mechanism on ladderphane copolymers with electron localization and phonon delocalization for capacitive energy storage
Authors: Wu Yuqiang , Sun Mengtao
Published: October 2023

In this article, the properties of trapezoidal polymer PSBNP-co-PTNI for capacitive energy storage are investigated theoretically, stimulated by the recent experimental reports [Chen et al., Nature 615, 62 (2023)]. The flatband structures of PSBNP-co-PTNI copolymer reveal that very large effective mass of electron results in Anderson electron localization and then small electric conductance. The TNI doping significantly decreases optical absorption in an ultraviolet region, which can significantly suppress photocurrent. Raman spectrum demonstrates that phonon Debye temperature can be significantly decreased, due to the U-process of phonon scattering by TNI doping, and then results in the phonon delocalization, and then the large thermal conductivity and thermal capacity. The simultaneous regulations on decreasing electric conductivity and on increasing thermal conductivity can significantly increase the ability of capacitive energy storage. The unit-length dependent thermal electric current manifests that the thermal electric current can be significantly decreased by slightly increase in length of copolymer. Overall, our research contributes to the understanding of the impact of TNI doping on the energy storage properties of the polymer and provides a valuable reference for future research focused on polymer energy storage.
High-order phase reduction for coupled 2D oscillators
Authors: Mau Erik T. K. , Rosenblum Michael , Pikovsky Arkady
Published: October 2023

Phase reduction is a general approach to describe coupled oscillatory units in terms of their phases, assuming that the amplitudes are enslaved. The coupling should be small for such reduction, but one also expects the reduction to be valid for finite coupling. This paper presents a general framework, allowing us to obtain coupling terms in higher orders of the coupling parameter for generic two-dimensional oscillators and arbitrary coupling terms. The theory is illustrated with an accurate prediction of Arnold’s tongue for the van der Pol oscillator exploiting higher-order phase reduction.
Generating vector beams by modulating and superimposing multiple polarization modes within a helium-neon resonant cavity
Authors: Wang Chencheng , Zhang Qingli , Wang Guanxue , Dong Xiangmei , Liu Yi , Weng Xiaoyu , Gao Xiumin
Published: October 2023

In recent years, vector beams, which have greater control freedom due to their non-uniform spatial polarization distribution, have received extensive attention from scholars. In this paper, we present a straightforward intracavity modulation method by increasing the volume of the gas gain medium inside the cavity to induce multimode oscillation. Subsequently, Brewster windows and a curved-output mirror are used to achieve polarization control and superposition of multiple modes within the cavity to generate stable and controllable vector beams. In addition, the polarization purity of the radial vector beam and the angular vector beam can reach 87.98% and 85.52%, respectively. This work can not only break the understanding of the traditional vector beam generation method and deepen the understanding of laser cavity regulation technology but also play a guiding role in designing compact vector lasers.
Scheme of acoustic radiation force on general uniform structure
Authors: Gong Menyang , Qiao Yupei , Xu Xin , Liu Jiehui , He Aijun , Liu Xiaozhou
Published: October 2023

Acoustic manipulation based on acoustic radiation force (ARF) is an important structure manipulation method, which has a wide application prospect in particle manipulation. The calculation of ARF received by regular particles has been extensively studied. In this paper, the scheme of ARF acting on general structure is proposed. The analytical relationship between the ARF and the velocity potential distribution of the scattering on a specified envelope surface is established directly. The irregular surface integration is extended to a custom surface, which is easy to be processed. The results of the analytical solution and the finite element simulation are given to verify its simplicity and accuracy. This solution has a significant improvement compared with the traditional calculation methods based on definitions, especially avoiding the integration upon complex surfaces. The proposal of this complete scheme makes it possible to calculate the analytical ARF acting on structure with any surface description and lays a complete theoretical foundation for the wide application of ARF in structure and particle manipulation.
High-quality MOCVD-grown heteroepitaxial gallium oxide growth on III-nitrides enabled by AlOx interlayer
Authors: Lee Junhee , Gautam Lakshay , Razeghi Manijeh
Published: October 2023

We report high-quality Ga2O3 grown on an AlGaN/AlN/Sapphire in a single growth run in the same Metal Organic Chemical Vapor Deposition reactor with an AlOx interlayer at the Ga2O3/AlGaN interface. AlOx interlayer was found to enable the growth of single crystalline Ga2O3 on AlGaN in spite of the high lattice mismatch between the two material systems. The resulting nitride/oxide heterogenous heterostructures showed superior material qualities, which were characterized by structural, electrical, and optical characterization techniques. In particular, a significant enhancement of the electron mobility of the nitride/oxide heterogenous heterostructure is reported when compared to the individual electron mobilities of the Ga2O3 epilayer on the sapphire substrate and the AlGaN/AlN heterostructure on the sapphire substrate. This enhanced mobility marks a significant step in realizing the next generation of power electronic devices and transistors.
On the unsteady wake flow behind a sphere with large transverse-rotating speeds
Authors: Li Zhuoyue , Zhang Di , Liu Yakun , Azma Aliasghar , Gao Nan
Published: October 2023

The unsteady wake downstream of a spinning sphere with a Reynolds number of 7930 (Re=UoD/ν, based on the sphere diameter and the free-stream velocity) and a range of spinning ratios (the ratio between the surface velocity and free-stream velocity, α=Vs/Uo) from 0 to 6.0 were studied using time-resolved particle image velocimetry. The Reynolds stresses and proper orthogonal decomposition results indicated that the wake exhibited distinct features in different spinning ratio regimes, and the state of the boundary layer played an important role in forming these features. In regime I (α≤0.25) where the boundary layer around the sphere was laminar, a pair of counter-rotating vortices emerged in the wake with unsteady size and position. The bottom boundary layer transitioned from laminar to turbulent as α increased from 0.25 to 0.75 (regime II). The transition caused a significant increase in the stream-wise stress as the unsteadiness becomes more coherent. The sphere was gradually covered by the turbulent boundary layer as α increased in regimes III and IV (0.75<α≤3.0). A large separation bubble was created in cases with α>3.0 (regime V); flow structures with a large stream-wise momentum separated from the bubble and was shed downstream with a strong flapping motion in the vertical direction, leading to large vertical stress behind the sphere.
Structural, optical, Raman characteristics of C-nanospheres incorporated Gd2O3:SeO2 nanoclusters for energy storage applications
Authors: Adimule Vinayak , Manhas Nidhi , Sharma Kalpana , Bathula Chinna
Published: October 2023

In the present work, novel nanocrystals (NCs) of carbon nanospheres (Cx) (5%, 10%, and 15%) anchored on Gd3+:SeO2 (Cx:Gd3+@SeO2) were synthesized and characterized by XRD (x-ray diffraction), SEM (scanning electron microscopy), SEM-energy dispersive x-ray, UV-visible, x-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, and Raman analytical techniques. XRD analysis showed that the synthesized Cx:Gd3+@SeO2 NCs exhibit mixed tetragonal phase. Gd3+@SeO2 NCs transformed into irregular flake-like morphology with increasing percentage of Cx. Optical property studies showed the presence of Cx in Gd3+@SeO2 NCs matrix leads to tuning of bandgap (Eg). Incorporation of Cx leads to decrease in the bandgap from 3.64 to 3.58 eV. XPS investigation revealed chemical composition and valence state of Cx:Gd3+@SeO2 NCs. Carbon-based materials, especially, carbon nanospheres, have attracted much attention due to their good conductivity, low cost, high surface area, porosity, etc. Upon doping Cx, the conducting network of the Gd3+@SeO2 lattice is improvised, which forms hollow structures and facilitates penetration of the electrolyte. Raman studies confirmed the formation of Gd-O-Gd/Gd2O3, Se-O-Se/SeO2, and C-H (D and G) fringes. Supercapacitor properties of Cx:Gd3+@SeO2 NCs investigated in 3M KOH solution using three electrode system showed specific capacitance of 239.4 F/g at current density of 0.5 A/g with 89% capacitance retention over 3000 cycles. The synthesized nanocrystals can be used as potential candidates for optical devices and battery applications.
Simultaneous dual-channel data transmission through a multimode fiber via wavefront shaping
Authors: Luo Jiawei , Liang Jiajun , Wu Daixuan , Huang Yin , Chen Zhiwei , Liu Zhibing , Zou Dongdong , Li Fan , Shen Yuecheng
Published: October 2023

The increasing demand for transmission capacity in fiber-optic communications makes multimode fibers (MMFs) attractive by enabling simultaneous multi-channel data transmission. However, inherent mode crosstalk among transmission channels limits its applicability. In this Letter, we propose to overcome this problem via wavefront shaping. By actively modulating the incident light with a special wavefront, not only the transmitted power for a specific channel can be enhanced but also crosstalk among different transmission channels can be mitigated. As a proof of concept, we experimentally demonstrated wavefront shaping assisted dual-channel optical communications through a single MMF. 10 Gbaud four-level pulse amplitude modulation signals were sent through both channels simultaneously, enabling a total bit rate of 40 Gbps. Both channels were analyzed with bit error rates below the hard-decision forward error correction limit, confirming the validity of the proposed scheme.
Phage display uncovers a sequence motif that drives polypeptide binding to a conserved regulatory exosite of O-GlcNAc transferase
Authors: Alteen Matthew G. , Meek Richard W. , Kolappan Subramania , Busmann Jil A. , Cao Jessica , O’Gara Zoe , Chou Ying , Derda Ratmir , Davies Gideon J. , Vocadlo David J.
Published: October 2023

The modification of nucleocytoplasmic proteins by
O
-linked N-acetylglucosamine (
O
-GlcNAc) is an important regulator of cell physiology.
O
-GlcNAc is installed on over a thousand proteins by just one enzyme,
O
-GlcNAc transferase (OGT). How OGT is regulated is therefore a topic of interest. To gain insight into these questions, we used OGT to perform phage display selection from an unbiased library of ~10
9
peptides of 15 amino acids in length. Following rounds of selection and deep mutational panning, we identified a high-fidelity peptide consensus sequence, [Y/F]-x-P-x-Y-x-[I/M/F], that drives peptide binding to OGT. Peptides containing this sequence bind to OGT in the high nanomolar to low micromolar range and inhibit OGT in a noncompetitive manner with low micromolar potencies. X-ray structural analyses of OGT in complex with a peptide containing this motif surprisingly revealed binding to an exosite proximal to the active site of OGT. This structure defines the detailed molecular basis driving peptide binding and explains the need for specific residues within the sequence motif. Analysis of the human proteome revealed this motif within 52 nuclear and cytoplasmic proteins. Collectively, these data suggest a mode of regulation of OGT by which polypeptides can bind to this exosite to cause allosteric inhibition of OGT through steric occlusion of its active site. We expect that these insights will drive improved understanding of the regulation of OGT within cells and enable the development of new chemical tools to exert fine control over OGT activity.
Amine-recognizing domain in diverse receptors from bacteria and archaea evolved from the universal amino acid sensor
Authors: Cerna-Vargas Jean Paul , Gumerov Vadim M. , Krell Tino , Zhulin Igor B.
Published: October 2023

Bacteria possess various receptors that sense different signals and transmit information to enable an optimal adaptation to the environment. A major limitation in microbiology is the lack of information on the signal molecules that activate receptors. Signals recognized by sensor domains are poorly reflected in overall sequence identity, and therefore, the identification of signals from the amino acid sequence of the sensor alone presents a challenge. Biogenic amines are of great physiological importance for microorganisms and humans. They serve as substrates for aerobic and anaerobic growth and play a role of neurotransmitters and osmoprotectants. Here, we report the identification of a sequence motif that is specific for amine-sensing sensor domains that belong to the Cache superfamily of the most abundant extracellular sensors in prokaryotes. We identified approximately 13,000 sensor histidine kinases, chemoreceptors, receptors involved in second messenger homeostasis and Ser/Thr phosphatases from 8,000 bacterial and archaeal species that contain the amine-recognizing motif. The screening of compound libraries and microcalorimetric titrations of selected sensor domains confirmed their ability to specifically bind biogenic amines. Mutants in the amine-binding motif or domains that contain a single mismatch in the binding motif had either no or a largely reduced affinity for amines. We demonstrate that the amine-recognizing domain originated from the universal amino acid–sensing Cache domain, thus providing insight into receptor evolution. Our approach enables precise “wet”-lab experiments to define the function of regulatory systems and therefore holds a strong promise to enable the identification of signals stimulating numerous receptors.
Twisted: Escape of epitope-edited healthy cells from immune attack
Authors: Volta Laura , Manz Markus G.
Published: October 2023

Hematopoietic stem and progenitor cell–derived neoplasia is challenging to target by cell surface–directed immunotherapy due to lack of tumor cell–specific antigen identification. Marone et al. (2023. J. Exp. Med.https://doi.org/10.1084/jem.20231235) provide a solution by target-epitope resistance editing in healthy hematopoietic stem cells.
A hydraulic energy flow within the moving Earth
Authors: Herrmann Friedrich , Pohlig Michael
Published: October 2023

We consider the Earth moving through empty space at 30 km s−1 (in the Sun’s frame of reference). Associated with this motion is a convective flow of kinetic and internal energy. Since there is high pressure inside the Earth, and since the Earth is moving, there is yet another ‘hydraulic’ energy flow. This latter is what this article is about. Although this energy flow is huge, it is not addressed in the textbooks. The reason is that for the explanation one needs a concept which is not introduced in traditional presentations of classical gravitation: the gravitomagnetic field. The corresponding theory, gravitoelectromagnetism, was formulated in 1893 by Heaviside in analogy to Maxwell’s theory of electromagnetism. We discuss the question of what are the sources and sinks of this hydraulic, non-convective energy flow. To answer the question, we need to study the energy flow density distribution within the gravitational field. In doing so, we will make some interesting observations. The energy flow within the field is twice as large as it should be to transfer the field energy from one side of the Earth to the other. The excess flow goes back through the matter of the Earth. Since our readers may not be familiar with Heaviside’s theory, we first treat the electromagnetic analogue of our problem and then translate the results to the gravitational situation.
Relativistic mechanics and thermodynamics: IV. Thermodynamic processes
Authors: Güémez J , Mier J A
Published: October 2023

Two thermodynamic processes, an adiabatic gas compression and an isothermal gas compression, taking place in a moving lab are analysed using a four-vector fundamental equation, dE

μ
= δ
W

μ
+ δ
Q

μ
, a relativistic generalization of the first law of thermodynamics dE = δ
W + δ
Q. These processes are first described in frame S, with the lab at rest, and then in frame

S

¯

, moving with constant velocity relative to S. This formalism shows that Lorentz transformation preserves the principle of relativity in thermodynamics. The physical meaning of the norm of a four-vector is analysed, and Clausius definition of entropy variation is generalised to relativity. The classical description of the process is obtained in a moving lab by taking the low-speed limit in the four-vector fundamental equation. The formalism naturally incorporates the role of the laws of mechanics when analysing processes that are typically considered as purely thermodynamic.
Non-homogeneous pairing in disordered two-orbital s-wave superconductors
Authors: Caldas Heron , Rufo S , Griffith M A R
Published: October 2023

We investigate the effects of non-magnetic disorder in a hybridized two-dimensional two-orbital s-wave superconductor (SC) model. The situation in which electronic orbitals overlap such that the hybridization

V

i
,
j

among them is antisymmetric, under inversion symmetry, was taken into account. The on-site disorder is given by a random impurity potential W. We find that while the random disorder acts to the detriment of superconductivity, hybridization proceeds to favor it. Accordingly, hybridization plays an important role in two-orbital models of superconductivity, in order to hold the long-range order against the increase of disorder. This makes the present model eligible to describe real materials, since the hybridization may be induced by pressure or doping. In addition, the regime from moderate to strong disorder reveals that the system is broken into SC islands with correlated local order parameters. These correlations persist to distances of several order lattice spacing which corresponds to the size of the SC-Islands.
Study of electrochemical biosensor for determination of glucose based on Prussian blue/gold nanoparticles-chitosan nanocomposite film sensing interface
Authors: Peng Zhen , Li Zongyuan , Liao Jingru , Zhang Zhimi , Song Yangyang , Xia Cao , Xia Yuanlin , Wang Zhuqing
Published: October 2023

A highly electroactive bilayer composite film sensing interface of Prussian blue (PB)/gold nanoparticles-chitosan (AuNPs-CS) was modified on Au electrode through electrochemical deposition and coating method followed by integrating glucose oxidase (GOx) into the interfacial matrix to fabricate a high-performance glucose biosensor. The excellent electrocatalytic ability of the PB/AuNPs-CS composite film sensing interface for H2O2 was evaluated, which has a broad linear response of 0.01–7.95 mM, with a low detection limit (LOD) 0.269 μM and a high sensitivity of 511.82 μA·mM−1·cm−2. The enhanced electrocatalytic activity of this sensing interface for H2O2 is attributed to the protection from the network CS film to PB and the synergistic effect of PB and AuNPs. Consequently, an electrochemical biosensing interface was constructed with GOx immobilized as a model enzyme. The PB/GOx-AuNPs-CS biosensing nanocomposite film was capable of a fast steady-state response time (within 2 s) and high sensitivity to glucose with a wide linear range of: 0.025–2.00 mM (R
2 = 0.99), with a sensitivity of 40.41 μA·mM−1·cm−2 and a LOD of 1.62 μM; and 2.00–6.50 mM (R
2 = 0.98), with a sensitivity of 8.90 μA·mM−1·cm−2 and a LOD of 7.16 μM. The biosensor has good anti-interference and selectivity, which provides a promising wide linear range platform for clinical blood glucose detection in the future.
Predicting the miniaturization limit of vertical organic field effect transistor (VOFET) with perforated graphene as a source electrode
Authors: Shukla Gaurav , Bisht Ramesh Singh , Kumar Pramod
Published: October 2023

Vertical organic field effect transistors (VOFETs) are of paramount importance due to their fast switching speed, low power consumption, and higher density on a chip compared to lateral OFETs. The low charge carrier mobility in organic semiconductors and longer channel lengths in lateral OFETs lead to higher operating voltages. The channel length in VOFETs can be less than 100 nm which reduces the size of the channel and hence the operating voltages. Another important factor in the operation of VOFETs is the thickness and width of the source electrode. The channel length, source electrode thickness and width sets the miniaturization limit of the VOFETs. The graphene monolayer can be exploited as a source electrode due to its thinness, high carrier mobility, and metallic behaviors. However, for better gate modulation, perforations in the source material are desired. Here, we simulate the VOFET having perforated graphene monolayer as a source electrode and n-type organic semiconductor N, N′-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) as an active channel material, while aluminum as a drain electrode to predict the best-miniaturized device. The miniaturization limit of such a VOFET has a limit to the gate opening/perforation in which the minimum source width is 10 nm, as in the sub 10 nm range graphene starts behaving like a semiconductor. The subthreshold swing, deduced from the drain current (J
D) versus gate voltage (V
G) graph, advocates the limit of the organic semiconductor height/channel length to 50 nm, while 50 nm for the gate.
Enhanced hydrogen production via urea electrolysis over Ni-NiO electrodeposited on Ti mesh
Authors: Wang Yajing , Zhu Minjie , Xie Taiping , Liu Songli , Wang Jiankang
Published: October 2023

The sluggish kinetics of anodic oxygen evolution reaction (OER) is regarded as the main bottleneck for ineffective hydrogen production efficiency, limiting the industrial application of electrochemical water splitting. Substituting the OER by urea electrooxidation reaction (UOR) and simultaneously developing highly active and economical bifunctional electrocatalyst for UOR and hydrogen evolution reaction (HER) is a promising method to realize energy-saving hydrogen production and urea-rich wastewater abatement. Herein, self-supporting Ni-NiO film grown on Ti mesh (Ni-NiO/TM) was successfully prepared by a facile cathodic electrodeposition method with using nickel acetate as the only raw material. Electrodeposition process was optimized by modulating the electrodeposition time and potential. x-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and Raman characterization revealed the optimized Ni-NiO/TM was comprised of crystalline Ni and amorphous NiO and its morphology exhibited nanosphere structure, assembled by nanosheets. Ni-NiO/TM sample prepared under the potential of −1.5 V and deposition time of 10 min illustrated the lowest UOR potential of 1.34 V at 50 mA cm−2 and robust stability, superior to the recently reported literatures. Furthermore, the HER potential was only −0.235 V to drive the current density of 50 mA cm−2. The cell voltage of urea-assisted electrolysis for hydrogen production in Ni-NiO/TM||Ni-NiO/TM two-electrode system only required 1.56 V to deliver 50 mA cm−2, obviously lower than that (>1.72 V) for overall water splitting. This work demonstrated the potential of Ni-based material as bifunctional electrocatalyst for energy-saving H2 production by urea-rich wastewater electrolysis.
Tunable Mie resonance in complex-shaped gadolinium niobate
Authors: Sedova Anastasiya , Bermudez David , Tellez-Cruz Miriam M , Falcony Ciro
Published: October 2023

Nanoscale particles described by Mie resonance in the UV–vis–NIR region are in high demand for optical applications. Controlling the shape and size of these particles is essential, as it results in the ability to control the wavelength of the Mie resonance peak. In this work, we study the extensive scattering properties of gadolinium niobate particles with complex bar- and cube-like shapes in the UV–vis–NIR region. We perform our experimental analysis by characterizing the morphology and extinction spectra, and our theoretical study by implementing a Mie scattering model for a distribution of spherical particles. We can accurately model the size distribution and extinction spectra of complex shaped particles and isolate the contribution of aggregates to the extinction spectra. We can separate the contributions of dipoles, quadrupoles, and octupoles to the Mie resonances for their respective electric and magnetic parts. Our results show that we can tune the broad Mie resonance peak in the extinction spectra by the nanoscale properties of our system. This behavior can aid in the design of lasing and luminescence-enhanced systems. These dielectric gadolinium niobate submicron particles are excellent candidates for light manipulation on the nanoscale.
3D printed auxetic stents with re-entrant and chiral topologies
Authors: Alomarah Amer , Al-Ibraheemi Zahraa A , Ruan Dong
Published: October 2023

The mechanical performance of the medical stent is crucial and of key significance to the dependability and reliability of the stent-plaque-artery system. In this study, an auxetic stent, namely, re-entrant chiral auxetic (RCA) is proposed. Two types of stent (RCA-X and RCA-Y) are proposed. The RCA stents are designed through a periodic distribution of two dimensional (2D) RCA cells along both the circumferential and axial directions. A set of polyimide specimens were 3d printed using Multi-Jet Fusion process. The compressive properties of the 3d printed stents were experimentally examined, while the tensile properties were numerically investigated. Results showed that the RCA-X stent revealed a remarkable radial expansion (i.e. auxetic features) of approximately 50% while the RCA-Y stent showed radial expansion of 16.7%. Despite the auxetic features of the compressed stents, asymmetric deformation patterns were resulted in the case of the RCA-X while uniform patterns were resulted in the case of the RCA-Y. The FE models were further employed to examined the effects of number of unit cells along the circumferential direction on the auxetic features. The auxetic features of the developed stents could be controlled by adjusting the geometric parameters of the RCA’s cell and number of cells along the circumferential direction. The promising properties of the RCA stents might sheds the light on the design auxetic stents for practical clinical applications.
Study on the motion of single particle chain in the magnetorheological fluid under the action of traveling magnetic field
Authors: Sun Zebang , Liu Shaogang , Zhao Dan , Dong Liqiang , Qi Jinming , Guo Chang
Published: October 2023

Magnetorheological fluid (MRF) is a widely used intelligent material that can quickly respond to external magnetic fields. To effectively control the motion of the particle chain inside the MRF, this paper combines the traveling magnetic field (TMF) with the MRF to study the movement of the single particle chain in the MRF under the action of the TMF for the first time and discusses the influence of the moving velocity of the TMF and the magnetic induction intensity on the motion displacement and the velocity of the single particle chain, determines the adjustable range of the single particle chain motion parameters, and builds an experimental platform to observe the motion of the single particle chain. The results show that under the action of the TMF, the single particle chain makes a variable velocity reciprocating motion, and the displacement amplitude of the single particle chain is inversely proportional to the moving velocity of the TMF but directly proportional to the magnetic induction intensity of the TMF. The single particle chain velocity amplitude is only proportional to the magnetic induction intensity and is unrelated to the moving velocity of the TMF. This study shows that adjusting the TMF parameters can effectively control the displacement and velocity of single particle chain motion. This study provides a compelling new method to control the motion pattern of single particle chains in MRF.
Uncertainties of critical temperatures based on higher-order fluctuations of the largest fragment charge*
Authors: Xiao 肖 Erxi 尔熙 , Lei 雷 Xin 昕 , Huang 黄 Yingge 英格 , Feng 冯 Yujie 玉洁 , Zhu 祝 Long 龙 , Su 苏 Jun 军
Published: October 2023

The new signature of liquid-gas phase transition has been well indicated by the higher-order fluctuations of the largest fragment charge, but the uncertainties of critical temperatures based on this signature have not been revealed. This study extracts the critical temperatures of liquid-gas phase transition in nuclear reactions and investigates their uncertainties. Utilizing the isospin-dependent quantum molecular dynamics model in conjunction with the statistical model GEMINI enables us to describe the dynamical path from the initial to the final state. An isotope thermometer and a quantum fluctuation thermometer are employed to extract the nuclear temperature. The higher-order fluctuations of the largest fragment charge and critical temperatures are studied in 124Sn + 120Sn collisions ranging from 400 to 1000 MeV/nucleon and 124Sn + AZ collisions at 600 MeV/nucleon. Observations revealed that the pseudo-critical point is robustly indicated by the higher-order fluctuations of the largest fragment charge. The critical temperatures extracted by the isotope thermometer are relatively consistent, with an uncertainty of 15%, while those obtained by the quantum fluctuation thermometer are heavily influenced by the incident energy and mass number of target nuclei. The excitation energy

and bound charge

are used for event-sorting. These two ensembles represent the statistical properties of the initial and final states of the system, respectively. The initial-final correlations of statistical properties might lead to two phenomena. First, the size distribution of the largest fragment at the pseudo-critical point based on the

ensemble is wide, while that based on

ensemble exhibits bimodality, which is a typical characteristic in the liquid-gas coexistence of a finite system. Second, the temperature at the pseudo-critical point based on the

ensemble is higher than that based on the

ensemble. Furthermore, the projectile-like system exhibits a significant dynamical effect in its evolution path from the initial to final state, closely associated with the fluctuation of critical temperature.
First evaluation of the primary frequency standard NTSC-CsF2
Authors: Wang Xin-Liang , Ruan Jun , Liu Dan-Dan , Guan Yong , Shi Jun-Ru , Yang Fan , Bai Yang , Zhang Hui , Fan Si-Chen , Wu Wen-Jun , Zhao Shu-Hong , Zhang Shou-Gang
Published: October 2023

Caesium fountain primary frequency standards have been used to realize the definition of the second in the International System of units for more than two decades. This paper reports the structure and uncertainty evaluation of the NTSC-CsF2, developed by National Time Service Center (NTSC), Chinese Academy of Sciences. The short-term stability at high atomic density is 2.1 × 10−13 at 1 s of averaging time. The fractional combined type B uncertainty is evaluated at 4.3 × 10−16. A frequency comparison has been conducted between NTSC-CsF2 and the SI second through a Global Navigation Satellite System link for eight months whose results show a fractional frequency difference of 4.2(5.2) × 10−16. With a reduced chi-square of 0.8, NTSC-CsF2 is found to be consistent with that of the other fountains within the uncertainty.
Lattice constant and polarization-independent high transmission in tellurium-based dielectric metasurfaces
Authors: Sadasivan Jayesh , Krishnan Sivarama , Dontabhaktuni Jayasri
Published: October 2023

High-refractive-index dielectric metasurfaces give rise to unprecedented control of light manipulation, such as control of phase, polarization and amplitude, giving rise to interesting properties, such as directional beam steering, polarization detectors and sensors. Dielectric metasurfaces of sub-wavelength dimensions have tremendous applications in the field of optics, such as negative refractive index, cloaking, perfect absorbers and reflectors. The study of light–matter interactions in such materials has gained impetus due to the formation of novel states, such as anapoles, and transparent states obtained by interference between resonant electric, magnetic and higher-order modes. In this article, we investigate the light–matter interaction of an array of periodic dielectric metasurfaces made from high-refractive-index tellurium in cubic geometries and study its electromagnetic response as a function of the lattice constant, angle of incidence and angle of polarization. More specifically, we observe a non-resonant transparent state at 60.69 THz, which is independent of both the lattice constant and polarization of the input radiation. Moreover, this state shows high transmission for a broad range of incident angles with potential applications as optical filters. It also depends on the incident polarization, thus acting as a perfect polarization detector. Detailed investigations of scattering parameters, the spatial distribution of electric and magnetic fields in the near- and far-field regions and detailed multipole analysis are carried out to analyze the electromagnetic response of the metasurface.