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Spontaneous Infection and Periodic Evolving of Domain in a Diffusive SIS Epidemic Model

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 164-191页

作者： qiang wen Guo-qiang Ren Bin Liu School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan430074China

In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. Further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.

关键词： diffusive SIS model spontaneous infection periodically evolving domain periodic endemic equilibrium

A mixed-coordination electron trapping-enabled high-precision touch-sensitive screen for wearable devices

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Bio-Design and Manufacturing 2024年第4期7卷 413-427页

作者： Xi Zhang Junchi Ma Hualin Deng Jinming Zhong Kaichen Xu qiang wu Bo wen Dongfeng Diao Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310058China Shenzhen University General Hospital Shenzhen 518055China Research Center of Medical Plasma Technology Shenzhen UniversityShenzhen 518060China

Touch-sensitive screens are crucial components of wearable *** such as reduced graphene oxide(rGO),carbon nanotubes(CNTs),and graphene offer promising solutions for flexible touch-sensitive ***,when stacked with flexible substrates to form multilayered capacitive touching sensors,these materials often suffer from substrate delamination in response to deformation;this is due to the materials having different Young’s modulus *** results in failure to offer accurate touch screen *** this work,we demonstrate an induced charge-based mutual capacitive touching sensor capable of high-precision touch *** is enabled by electron trapping and polarization effects related to mixed-coordinated bonding between copper nanoparticles and vertically grown graphene ***,we used an electron cyclotron resonance system to directly fabricate graphene-metal nanofilms(GMNFs)using carbon and copper,which are firmly adhered to flexible *** being subjected to 3000 bending actions,we observed almost no change in touch *** screen interaction system,which has a signal-to-noise ratio of 41.16 dB and resolution of 650 dpi,was tested using a handwritten Chinese character recognition trial and achieved an accuracy of 94.82%.Taken together,these results show the promise of touch-sensitive screens that use directly fabricated GMNFs for wearable devices.

关键词： Flexible touch-sensitive screen Graphene-metal nanofilms Mixed coordination Wearable device

Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

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National Science Review 2024年第3期11卷 159-171页

作者： Rui wen Shao Jun Wei wu Zheng Xing Wang Hui Xu Han Qing Yang qiang Cheng Tie Jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng Cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

Efficiently simulating the work distribution of multiple identical bosons with boson sampling

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Frontiers of physics 2024年第3期19卷 197-206页

作者： wen-qiang Liu Zhang-qi Yin Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements(MOE) School of PhysicsBeijing Institute of TechnologyBeijing 100081China

Boson sampling has been theoretically proposed and experimentally demonstrated to show quantum computational ***,it still lacks the deep understanding of the practical applications of boson *** we propose that boson sampling can be used to efficiently simulate the work distribution of multiple identical *** link the work distribution to boson sampling and numerically calculate the transition amplitude matrix between the single-boson eigenstates in a one-dimensional quantum piston system,and then map the matrix to a linear optical network of boson *** work distribution can be efficiently simulated by the output probabilities of boson sampling using the method of the grouped probability *** scheme requires at most a polynomial number of the samples and the optical *** work opens up a new path towards the calculation of complex quantum work distribution using only photons and linear optics.

关键词： quantum simulation quantum work distribution boson sampling linear optic

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong wu qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Construction of Z-scheme Cu-CeO_(2)/BiOBr heterojunction for enhanced photocatalytic degradation of sulfathiazole

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Chinese Chemical Letters 2024年第7期35卷 167-172页

作者： Xingmin Chen Yunyun wu Yao Tang Peishen Li Shuai Gao qiang Wang wen Liu Sihui Zhan College of Environmental Sciences and Engineering Nankai UniversityTianjin 300350China Laboratory for Micro-Sized Functional Materials&College of Elementary Education and Department of Chemistry Capital Normal UniversityBeijing 100048China College of Environmental Sciences and Engineering The Key Laboratory of Water and Sediment Sciences(MOE)Peking UniversityBeijing 100871China

The utilization of an efficient photocatalyst is crucial for the photocatalytic degradation of antibiotics in water through visible light,which is an imperative requirement for the remediation of water *** this study,a novel Cu-CeO_(2)/BiOBr Z-type heterojunction was synthesized by calcination and hydrothermal methods,and the degradation rate of sulfathiazole(STZ)antibiotic solution was studied using simulated illumination(300 W xenon lamp).The results indicated that 3%Cu-CeO_(2)/BiOBr achieved a degradation rate of 92.3%within 90 min when treating 20 mg/L STZ solution,demonstrating its potential for practical water treatment *** using various chemical instruments revealed that 3%Cu-CeO_(2)/Bi OBr exhibited the lowest electron-hole recombination rate and electron transfer ***,the utilization of ESR data and quenching experiments has substantiated the involvement of hydroxyl radicals(·OH)and superoxide radicals(·O_(2)^(-))as the primary active ***,a plausible degradation mechanism has been *** findings offer a prospective approach for the development of heterojunction materials with appropriate band matching.

关键词： Cu-CeO_(2)/BiOBr nanoheterojunction Photocatalytic degradation Sulfathiazole Z-scheme

A bibliometric analysis of molybdenum-based nanomaterials in the biomedical field

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Tungsten 2024年第1期6卷 17-47页

作者： Zhi-qiang Wang Ya-wen Pan Jing wu Hong-Bin Qi Shuang Zhu Zhan-Jun Gu School of Science China University of GeosciencesBeijing 100083China CAS Key Laboratory for Biomedical Eff ects of Nanomaterials and Nanosafety Institute of High Energy PhysicsBeijing 100049China CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology of ChinaChinese Academy of SciencesBeijing 100190China College of Materials Science and Optoelectronic Technology University of Chinese Academy of SciencesBeijing 100049China

Molybdenum(Mo)-based nanomaterials have been widely used in biomedical fields due to their various nanostructures and unique physical/chemical *** various reviews have described the development of Mo-based materials in the biomedical field,an objective and comprehensive summary and analysis of research trends in this field is still ***,we used the bibliometric analysis method to analyze all relevant literature on the biological application of Mobased nanomaterials in recent ***,we use bibliometric tools to analyze the dataset by year,country/region,institution and research hotspot to obtain the research ***,based on objectively identified research hotspots,the biomedical applications of Mo-based nanomaterials are reviewed comprehensively,mainly including sensors,cancer imaging/therapy and antibacterial ***,we discussed the application prospects and challenges of Mo-based *** article provides a new perspective to understand the current research progress and further promote the development of Mobased nanomaterials in biomedical research.

关键词： Molybdenum Nanomaterial Biomedicine Bibliometric analysis

Brain Cognition Mechanism-Inspired Hierarchical Navigation Method for Mobile Robots

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Journal of Bionic Engineering 2024年第2期21卷 852-865页

作者： qiang Zou Chengdong wu Ming Cong Dong Liu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110819China School of Mechanical Engineering Dalian University of TechnologyDalian116024China

Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist poor robustness and low cognitive *** a new navigation technology that draws inspiration from mammal’s navigation,bionic navigation method can map perceptual information into cognitive space,and have strong autonomy and environment *** improve the robot’s autonomous navigation ability,this paper proposes a cognitive map-based hierarchical navigation ***,the mammals’navigation-related grid cells and head direction cells are modeled to provide the robots with location *** then a global path planning strategy based on cognitive map is proposed,which can anticipate one preferred global path to the target with high efficiency and short ***,a hierarchical motion controlling method is proposed,with which the target navigation can be divided into several sub-target navigation,and the mobile robot can reach to these sub-targets with high confidence ***,some experiments are implemented,the results show that the proposed path planning method can avoid passing through obstacles and obtain one preferred global path to the target with high efficiency,and the time cost does not increase extremely with the increase of experience nodes *** motion controlling results show that the mobile robot can arrive at the target successfully only depending on its self-motion information,which is an effective attempt and reflects strong bionic properties.

关键词： Bionic navigation Spatial localization cells Global path planning Hierarchical motion controlling

The Sequential Pricing of Ride-Hailing System with Rental Service in the Context of Fleet Electrification

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 77-105页

作者： Yaoyao Ku Peng wu qiang Ren Yiqing Wang Business School Sichuan UniversityChengdu610065China

Surging demand and reduced capacity in the ride-hailing industry have prompted numerous ride-hailing platforms to build their own car-rental services catering to drivers who do not possess private vehicles. However, the trade-off between the ride-hailing service and the car-rental service is an important issue that is still unclear in theory. Moreover, ride-hailing platforms are transitioning towards all-electric fleets in the context of Carbon Neutrality goals and government regulations. This paper considers a ride-hailing system comprising a monopolist ride-hailing platform, an electric vehicle (EV) rental firm, and a gasoline vehicle (GV) rental firm. Furthermore, we build a stylized model to study the sequential pricing of the system. The equilibrium outcomes show the significant impact of the ride-hailing platform’s decision to continue or withdraw offering EV rental services on EV and GV drivers’ net earnings, rental prices, and wages. The ride-hailing platform providing EV rental services increases EV drivers’ net earnings but decreases the GV driver wages and rental prices. However, the EV rental service offered by the ride-hailing platform does not necessarily lead to an increased total profit for the system. The improved profitability of the system by the ride-hailing platform providing EV rental services is contingent upon lower rider prices and higher fuel costs. The ride-hailing platform’s EV rental services provision also effectively fosters the ride-hailing fleet’s electrification. Furthermore, as the number of riders increases, the ride-hailing platform should reduce the commission rate for EV drivers to maintain competitiveness and profitability.

关键词： Ride-hailing system car rental fleet electrification sequential pricing differential wage scheme