作者机构：
[Zihao Yu; Hai Lin; Rui Zhou] College of physical science and technology, Central China Normal University, Wuhan 430079, China;[Yiting Wang] Tobacco Hubei Industrial LLC, WUHAN Cigarette Factory, Wuhan 430000, China
通讯机构：
[Hai Lin] C;College of physical science and technology, Central China Normal University, Wuhan 430079, China
摘要：
Terahertz sensors with high sensitivity are essential for accurately detecting substances in various fields such as medical research, diagnostics, security, and molecular analysis. Their effectiveness relies on detecting small index changes that indicate a target, requiring resonance with an extremely high Q factor. Notably, taking advantage of topological corner states with narrow spectral widths and constant eigenfrequencies is a powerful strategy to attain high Q values. Combining the topological edge modes of valley twist states and high-order corner states, we have designed a topological sensor composed of a topological cavity and topological waveguide. The proposed sensor possesses an ultra-high Q value of up to 1.02×105. The exceedingly narrow linewidth of the topological cavity allows it to detect even the slightest changes in the spectrum, resulting in a high sensitivity of up to 2.06THz/RIU and a notable Figure of Merit (FoM) standing at 3.86×104. Moreover, the sensor is robust to structural disorder and defects inherent in fabrication processes, ensuring reliable performance in practical applications in different environments and manufacturing conditions.
作者机构：
[Yang, Xi-Yan] Yangtze Univ, Sch Phys & Optoelect Engn, Jingzhou 434023, Peoples R China.;[Lai, Xiao-Yu; Tan, Wei-Wei; Yang, Xi-Yan] Hubei Univ Educ, Res Ctr Astron, Wuhan 430205, Peoples R China.;[Tan, Wei-Wei] Cent China Normal Univ, Key Lab Quark & Lepton Phys, Minist Educ, Wuhan 430079, Peoples R China.;[Xu, Ren-Xin] Peking Univ, Sch Phys, Beijing 100871, Peoples R China.;[Xu, Ren-Xin] Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China.
通讯机构：
[Lai, XY ] H;Hubei Univ Educ, Res Ctr Astron, Wuhan 430205, Peoples R China.
关键词：
dense matter;(stars:) pulsars: general;(stars:) gamma-ray burst: general
摘要：
Strangeon stars, which are proposed to describe the nature of pulsar-like compact stars, have passed various observational tests. The maximum mass of a non-rotating strangeon star could be high, which implies that the remnants of binary strangeon star mergers could even be long-lived massive strangeon stars. We study rigidly rotating strangeon stars in the slowly rotating approximation, using the Lennard-Jones model for the equation of state. Rotation can significantly increase the maximum mass of strangeon stars with unchanged baryon numbers, enlarging the mass-range of long-lived strangeon stars. During spin-down after merger, the decrease of radius of the remnant will lead to the release of gravitational energy. Taking into account the efficiency of converting the gravitational energy luminosity to the observed X-ray luminosity, we find that the gravitational energy could provide an alternative energy source for the plateau emission of X-ray afterglow. The fitting results of X-ray plateau emission of some short gamma-ray bursts suggest that the magnetic dipole field strength of the remnants can be much smaller than that of expected when the plateau emission is powered only by spin-down luminosity of magnetars.
期刊：
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences,2024年 ISSN：0916-8508
作者机构：
[Xiaopeng JIAO] School of Computer Science and Technology, Xidian University;[Yun JIANG; Huiyang LIU; Ji WANG; Qiaoqiao XIA] College of Physical Science and Technology, Central China Normal University
摘要：
Currently, most fatigue driving detection methods rely on complex neural networks whose feasibility in hardware implementation needs to be further improved. This paper proposes an embedded device-oriented fatigue driving detection method based on a lightweight YOLOv5s. Firstly, a YOLOv5s face detection network with a parametric-free attention mechanism is designed to enhance the focus on face regions during face detection. Then, a practical facial landmark detector model is improved by integrating multi-scale feature fusion with Ghost module, which can adapt to the variations brought by different scale targets. Next, a fatigue determination approach is investigated by using multiple features of the face. Finally, experiments of the proposed detection model with the public YawDD dataset are implemented on the PC platform and the embedded device, respectively. The experimental results demonstrate that the proposed method achieves a detection accuracy of 95.3% and a processing speed of 22FPS on the PC platform. Meanwhile, the hardware test on an Orange Pi5 embedded device achieves a detection accuracy of 93.3% and a processing speed of 12FPS, which has good prospects for applications.
摘要：
BACKGROUND: Deaths from COVID-19 are concentrated in older adults, and studies have reported that physical activity (PA) can reduce the risk of death from pneumonia. METHODS: Eight cohort studies and 2 case-control studies were included according to the inclusion and exclusion criteria established in this meta-analysis study followed the PRISMA guideline, 8 cohort studies and 2 case-control studies were finally included. Then, the research objects in these studies were classified to further study the dose-response relationship and non-dose-response relationship. RESULTS: The highest dose of PA reduced the risk of death by 59% (risk ratio = 0.41; 95% confidence interval: 0.23-0.58) compared with the lowest dose of PA in middle-aged and elderly people. Furthermore, when the PA level was <10 m/wk, the risk of death from pneumonia was reduced by 6% every 4.5 MET-h/wk increase. At a PA level > 10 m/wk, the risk of death from pneumonia increased by 5% every 4.5 MET-h/wk increase. At a PA level > 30 m/wk, PA is a risk factor for pneumonia-related death in middle-aged and elderly people. CONCLUSIONS: This meta-analysis showed that PA was associated with a reduced risk of dying from pneumonia in middle-aged and older adults, and that there was a significant nonlinear negative dose-response relationship between PA levels and the risk of dying from pneumonia. Therefore, moderate exercise was recommended.
摘要：
In this study, we compute the electromagnetic and hadronic decay widths of the S-wave fully heavy tetraquark T4Q (Q = c or b) at lowest order in alpha s and v, in the framework of nonrelativistic QCD. The short-distance coefficients are determined through the standard procedure of matching. The nonperturbative long-distance matrix elements are related to the phenomenological four-body Schrodinger wave functions at the origin, whose values are taken from literature. The branching fractions are predicted to be around 10-3 and 10-6 for the T4c hadronic decay and electromagnetic decay, respectively. Combining our results with the T4c production cross sections at the LHC, we also predict the event numbers for various decay channels. With integrated luminosity L = 100 fb-1, it is expected that the event numbers can reach 103-104 for T4c -> gamma gamma, and 105-106 for T4c -> LH, at the LHC. The detecting prospect is promising. In addition, the decay widths of T4b are estimated based on simple dimensional analysis as well as velocity scaling rule.
关键词：
Energy splitting of STAR-RIS;time switching of STAR-RIS;UAV-enabled outdoor-to-indoor WPCN;indoor NFZ
摘要：
This letter investigates a Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface (STAR-RIS)-assisted unmanned aerial vehicle (UAV)-enabled outdoor-to-indoor (O2I) wireless powered communication network (WPCN), in which the UAV avoids flying over the indoor no-fly zone (NFZ). In the downlink energy transfer (DET) stage, the energy-constrained STAR-RIS and the O2I Internet of Things (IoT) devices harvest energy from the radio frequency (RF) signals of the UAV to self-sustain its operation. In the uplink information transmission (UIT) stage, the IoT devices transmit information to the UAV using the harvested energy, assisted by the STAR-RIS. We introduce the STAR-RIS energy splitting (ES) and time switching (TS) operating protocols in the DET and UIT stages, respectively, to maximize the harvested downlink energy and the achievable uplink sum-rate. Further, an alternating optimization (AO) algorithm based on the penalty method and successive convex approximation (SCA) technology is proposed to solve the resulting highly-coupled non-convex optimization problems, in which the UAV trajectory based on the UAV power consumption model, resource allocation of the O2I IoT devices, and beamforming vectors of the STAR-RIS are jointly optimized. Finally, numerical results demonstrate that our proposed scheme can achieve significant system sum-rate gains that are better than other baseline schemes.
摘要：
Calculating the thermal rate constants of elementary combustion reactions is of great importance in theoretical chemistry. Machine learning has become a powerful, data-driven method for predicting rate constants nowadays. Recently, the molecular similarity combined with the topological indices were proposed to represent the hydrogen abstraction reactions of alkane [J. Chem. Inf. Model. 2023, 63, 5097-5106], which are, however, not applicable to alkane cracking reactions, another important class of combustion reactions, due to the cleavage of the C-C bond. In this work, a new feature selection scheme is proposed to describe both bimolecular and unimolecular cracking reactions. Molecular descriptors are elaborately selected individually for both reactants and products from those generated by the open-source software RDKit. Machine learning models combined with these molecular descriptors are proven to have the ability to accurately predict rate constants of both the hydrogen abstraction reactions of alkanes by CH(3) and the alkane cracking reactions. The average deviation of the XGB-FNN model for prediction is around 60% for the hydrogen abstraction reactions of alkanes and 100% for the alkane cracking reactions. It is expected that the descriptors proposed in this work can be applied to build machine learning models for other reactions.
摘要：
Neuron constitutes the fundamental unit responsible for processing signals in the biological nervous system. The intricate anatomical structure and synaptic plasticity engender high adaptability to external stimuli and rich diversity of firing modes. This paper introduces a novel coupled functional neuron model and investigates its application in medical image encryption. Firstly, the thermistor and photocell are embedded in the nonlinear circuit to construct the thermosensitive model and the photosensitive neuron model. Then a new photo-thermal coupled neuron model is formulated by activating the linear resistor connection. Bifurcation analysis and complexity adjustment confirm the intricate dynamic behavior of the coupled neuron model. Next, an innovative ISI-encoded algorithm is created by capturing the interspike interval sequences of the model. Complexity comparison results exhibit that the ISI-encoded chaotic sequences are more stochastic and feasible compared to the original ones. Additionally, a novel medical image encryption scheme is developed by utilizing the constructed ISI-encoded chaotic sequence. The approach comprises of three stages: component disruption, row and column cyclic permutation, and an inventive diffusion based on Coulomb’s law. The scheme is tested on diverse medical images. Finally, the experimental performance and security analysis validate the efficiency of the designed encryption scheme and its promising robustness against numerous conceivable attacks. The information entropy of ciphertext images exceeds 7.99, and the correlation coefficients of adjacent pixels relatively approach 0. The NPCR and UACI values closely align with the theoretical values of 99.6094% and 33.4635%.
摘要：
In this paper, we study the gravitational waves of holographic QCD phase transition with hyperscaling violation. We consider an Einstein-Maxwell Dilaton background and discuss the confinement-deconfinement phase transition between thermally charged AdS and AdS black holes. We find that hyperscaling violation reduces the phase transition temperature. In a further study, we discuss the effect of hyperscaling violation on the GW spectrum. We found that the hyperscaling violation exponent suppresses the peak frequency of the total GW spectrum. Moreover, the results of the GW spectrum may be detected by IPTA, SKA, BBO, and NANOGrav. We also find that the hyperscaling violation exponent suppresses the peak frequency of the bubble-collision spectrum h2 Omega env. Hyperscaling violation enhances the energy densities of the sound wave spectrum h2 Omega sw and the MHD turbulence spectrum h2 Omega turb. The total GW spectrum is dominated by the contribution of the bubble collision in runaway bubbles case.
作者机构：
[Wu, Yanwen; Cao, Shuangshuang; Ma, Yanmei; Ge, Di] Cent China Normal Univ, Sch Phys Sci & Technol, Wuhan 430079, Peoples R China.;[Cheng, Yuhang] Shaanxi GSXZ Technol Co Ltd, Xian 710018, Peoples R China.;[Wu, Yanwen] Cent China Normal Univ, Natl Digital Learning Engn Technol Res Ctr, Wuhan 430079, Peoples R China.
通讯机构：
[Wu, YW ] C;Cent China Normal Univ, Sch Phys Sci & Technol, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Natl Digital Learning Engn Technol Res Ctr, Wuhan 430079, Peoples R China.
关键词：
Anomaly detection;Multivariate time-series;Spatiotemporal;Abnormal information expression;Graph contrastive learning
摘要：
The detection of anomalies in high-dimensional time-series has always played a crucial role in the domain of system security. Recently, with rapid advancements in transformer model and graph neural network (GNN) technologies, spatiotemporal modeling approaches for anomaly detection tasks have been greatly improved. However, most methods focus on optimizing upstream time-series prediction tasks by leveraging joint spatiotemporal features. Through experiments, we found that this modeling approach not only risks the loss of some original anomaly information during data preprocessing, but also focuses on optimizing the performance of the upstream prediction task and does not directly enhance the performance of the downstream detection task. We propose a spatiotemporal anomaly detection model that incorporates an improved attention mechanism in the process of temporal modeling. We adopt a heterogeneous graph contrastive learning approach in spatio modeling to compensate for the representation of anomalous behavioral information, thereby guiding the model through thorough training. Through validation on two widely used real-world datasets, we demonstrate that our model outperforms baseline methods. We also explore the impact of multivariate time-series prediction tasks on the detection task, and visualize the reasons behind the benefits gained by our model.
期刊：
JOURNAL OF HIGH ENERGY PHYSICS,2024年(5) ISSN：1029-8479
通讯作者：
Chen, SL
作者机构：
[Xiao, Yu-Qi; Chen, Shao-Long] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, 152 Luoyu Rd, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Chen, SL ] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
关键词：
Baryon/Lepton Number Violation;Other Weak Scale BSM Models;Specific BSM Phenomenology
摘要：
Neutrinoless double beta (0 nu beta beta) decay is the most promising way to determine whether neutrinos are Majorana particles. There are many experiments based on different isotopes searching for 0 nu beta beta decay. Combining the searches of 0 nu beta beta decay in multiple isotopes provides a possible method to distinguish operators and different models. The contributions to 0 nu beta beta decay come from standard, long-range, and short-range mechanisms. We analyze the scenario in which the standard and short-range operators exist simultaneously within the framework of low-energy effective field theory. Five specific models are considered, which can realize neutrino mass and can contribute to 0 nu beta beta decay via multiple mechanisms. A criterion to evaluate the possibilities of future experiments to discriminate operators and models is built. We find that the complementary searches for 0 nu beta beta decay in different isotopes can distinguish the cases that contain the low-energy effective operators O 1 , 2 , 5 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathcal{O}}_{1,2,5} $$\end{document} and R-parity violating supersymmetry model. For other cases and models, the experimental searches within multiple isotopes can also more effectively constrain the parameter region than with only one isotope.
期刊：
IEEE Transactions on Antennas and Propagation,2024年72(8):6464-6471
作者机构：
[Yuejie Yang; Cicheng Wang; Helin Yang; Shangru Li; Xiaofeng Zhou; Jing Jin] College of Physical Science and Technology, Central China Normal University, Wuhan, China
摘要：
In this article, a water-based metasurface for antenna radar cross section (RCS) reduction is proposed for the first time. The metasurface has a two-layer structure of metal patch and structural water and achieves more than 9 dB RCS reduction in the super high-frequency (SHF) band from 10.6 to 26 GHz based on the mechanism of phase cancellation and wave absorption. Low scattering characteristics are achieved in the X-, Ku-, and K-bands. By using the metasurface as a radiator and introducing a feed structure, a low-scattering antenna in the C-band can be obtained. The impedance bandwidth of the antenna is from 5.7 to 6.07 GHz. The proposed antenna has an extremely small size and low profile, high aperture efficiency, and directional high gain radiation characteristics. Additionally, it exhibits low scattering across a broad frequency band. This work verifies the feasibility of water-based metasurfaces for antenna RCS reduction.
期刊：
Nuclear Science and Techniques .,2024年35(7):44-53 ISSN：1001-8042
通讯作者：
Zhang, BW;Wang, S
作者机构：
[Li, Yao; Zhang, BW; Zhang, Ben-Wei; Shen, Shu-Wan] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Li, Yao; Zhang, BW; Zhang, Ben-Wei; Shen, Shu-Wan] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Wang, Sa; Wang, S] China Three Gorges Univ, Coll Sci, Yichang 443002, Peoples R China.;[Wang, Sa; Wang, S] China Three Gorges Univ, Ctr Astron & Space Sci, Yichang 443002, Peoples R China.;[Wang, Sa; Wang, S] China Three Gorges Univ, Inst Modern Phys, Yichang 443002, Peoples R China.
通讯机构：
[Wang, S ; Zhang, BW ] C;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;China Three Gorges Univ, Coll Sci, Yichang 443002, Peoples R China.;China Three Gorges Univ, Ctr Astron & Space Sci, Yichang 443002, Peoples R China.
摘要：
We present a theoretical study of the medium modifications of the
$$p_\textrm{T}$$
balance (
$$x_\textrm{J}$$
) of dijets in Xe+Xe collisions at
$$\sqrt{s_\textrm{NN}}=5.44$$
TeV. The initial production of dijets was carried out using the POWHEG+PYTHIA8 prescription, which matches the next-to-leading-order (NLO) QCD matrix elements with the parton shower (PS) effect. The SHELL model described the in-medium evolution of nucleus–nucleus collisions using a transport approach. The theoretical results of the dijet
$$x_\textrm{J}$$
in the Xe+Xe collisions exhibit more imbalanced distributions than those in the p+p collisions, consistent with recently reported ATLAS data. By utilizing the Interleaved Flavor Neutralisation, an infrared-and-collinear-safe jet flavor algorithm, to identify the flavor of the reconstructed jets, we classify dijets processes into three categories: gluon–gluon (gg), quark–gluon (qg), and quark–quark (qq), and investigated the respective medium modification patterns and fraction changes of the gg, qg, and qq components of the dijet sample in Xe+Xe collisions. It is shown that the increased fraction of qg component at a small
$$x_\textrm{J}$$
contributes to the imbalance of the dijet; in particular, the
$$q_1g_2$$
(quark-jet-leading) dijets experience more significant asymmetric energy loss than the
$$g_1q_2$$
(gluon-jet-leading) dijets traversing the QGP. By comparing the
$$\Delta \langle x_\textrm{J}\rangle = \langle x_\textrm{J} \rangle _\textrm{pp} - \langle x_\textrm{J} \rangle _\textrm{AA}$$
of inclusive,
$$c\bar{c}$$
and
$$b\bar{b}$$
dijets in Xe+Xe collisions, we observe
$$\Delta \langle x_\textrm{J} \rangle _\mathrm{incl.}>\Delta \langle x_\textrm{J} \rangle _\mathrm{c\bar{c}}>\Delta \langle x_\textrm{J} \rangle _\mathrm{b\bar{b}}$$
. Moreover,
$$\rho _\textrm{Xe, Pb}$$
, the ratios of the nuclear modification factors of dijets in Xe+Xe to those in Pb+Pb, were calculated, which indicates that the yield suppression of dijets in Pb+Pb is more pronounced than that in Xe+Xe owing to the larger radius of the lead nucleus.
通讯机构：
[Gu, WJ ] Y;[Li, GX ] H;Yangtze Univ, Sch Phys & Optoelect Engn, Jingzhou 434023, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We investigate the scattering processes of two photons in a one-dimensional waveguide coupled to two giant atoms. By adjusting the accumulated phase shifts between the coupling points, we are able to effectively manipulate the characteristics of these scattering photons. Utilizing the Lippmann-Schwinger formalism, we derive analytical expressions for the wave functions describing two-photon interaction in separate, braided, and nested configurations. Based on these wave functions, we also obtain analytical expressions for the incoherent power spectra and second-order correlation functions. In contrast to small atoms, the incoherent spectrum, which is defined by the correlation of the bound state, can exhibit more tunability due to the phase shifts. Additionally, the second-order correlation functions in the transmission and reflection fields could be tuned to exhibit either bunching or antibunching upon resonant driving. These unique features offered by the giant atoms in waveguide QED could benefit the generation of nonclassical itinerant photons in quantum networks.
