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Semantic segmentation-based semantic communication system for image transmission

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Digital Communications and Networks 2024年第3期10卷 519-527页

作者： Jiale Wu Celimuge Wu Yangfei Lin Tsutomu Yoshinaga Lei Zhong Xianfu Chen Yusheng Ji The University of Electro-Communication Tokyo182-8585Japan Toyota Motor Corporation Tokyo112-8701Japan VTT Technical Research Centre of Finland OuluFinland National Institute of Informatics(NII) Tokyo101-8430Japan

With the rapid development of artificial intelligence and the widespread use of the Internet of Things, semantic communication, as an emerging communication paradigm, has been attracting great interest. Taking image transmission as an example, from the semantic communication's view, not all pixels in the images are equally important for certain receivers. The existing semantic communication systems directly perform semantic encoding and decoding on the whole image, in which the region of interest cannot be identified. In this paper, we propose a novel semantic communication system for image transmission that can distinguish between Regions Of Interest (ROI) and Regions Of Non-Interest (RONI) based on semantic segmentation, where a semantic segmentation algorithm is used to classify each pixel of the image and distinguish ROI and RONI. The system also enables high-quality transmission of ROI with lower communication overheads by transmissions through different semantic communication networks with different bandwidth requirements. An improved metric θPSNR is proposed to evaluate the transmission accuracy of the novel semantic transmission network. Experimental results show that our proposed system achieves a significant performance improvement compared with existing approaches, namely, existing semantic communication approaches and the conventional approach without semantics.

关键词： Semantic Communication Semantic segmentation Image transmission Image compression Deep learning

Topological phases and edge modes of an uneven ladder

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Chinese Physics B 2024年第8期33卷 154-168页

作者：商文创韩熠宁 Shimpei Endo 高超 Department of Physics Zhejiang Normal UniversityJinhua 321004China Key Laboratory of Optical Information Detection and Display Technology of Zhejiang Zhejiang Normal UniversityJinhua 321004China Department of Engineering Science The University of Electro-CommunicationsTokyo 182-8585Japan

We investigate the topological properties of a two-chain quantum ladder with uneven legs,i.e.,the two chains differ in their periods by a factor of *** an uneven ladder presents rich band structures classified by the closure of either direct or indirect *** also provides opportunities to explore fundamental concepts concerning band topology and edge modes,including the difference of intracellular and intercellular Zak phases,and the role of the inversion symmetry(IS).We calculate the Zak phases of the two kinds and find excellent agreement with the dipole moment and extra charge *** also find that configurations with IS feature a pair of degenerate two-side edge modes emerging as the closure of the direct bandgap,while configurations without IS feature one-side edge modes emerging as not only the closure of both direct and indirect bandgaps but also within the band ***,by projecting to the two sublattices,we find that the effective Bloch Hamiltonian corresponds to that of a generalized Su–Schrieffer–Heeger model or the Rice–Mele model whose hopping amplitudes depend on the *** this way,the topological phases can be efficiently extracted through winding *** propose that uneven ladders can be realized by spin-dependent optical lattices and their rich topological characteristics can be examined by near future experiments.

关键词： ladder model symmetry-protected topological phase topological invariant bulk-boundary correspondence

Wettability,reactivity,and interface structure in Mg/Ni system

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Journal of Magnesium and Alloys 2024年第2期12卷 659-672页

作者： S.Terlicka N.Sobczak Ł.Maj P.Darłak J.J.Sobczak Institute of Metallurgy and Materials Science Polish Academy of Sciences25 Reymonta Str.KrakowPoland Faculty of Foundry Engineering AGH University23 Reymonta Str.KrakowPoland

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni *** comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)*** high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) *** the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate *** and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified *** was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθ<90°in<1 s),followed by fast spreading and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test ***,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

关键词： Magnesium-based alloys Sessile drop tests Capillary purification procedure Wettability Reactivity Contact angle

Generation of 160 nm vacuum ultraviolet light at 82 MHz in a KBBF crystal by the fifth-harmonic of a Ti:sapphire laser

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Chinese Optics Letters 2024年第5期22卷 95-99页

作者：张赟汪丽蓉 Department of Engineering Science The University of Electro-CommunicationsTokyo 182-8585Japan State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We report the generation of quasi-cw vacuum ultraviolet(VUV)light at 160 nm with a repetition rate of 82 MHz by two second-harmonic generations and one sum frequency *** VUV laser light is produced as a fifth-harmonic generation of a mode-locked ps Ti:sapphire laser system by successive stages with nonlinear crystals of LBO and KBBF.A stable generation of laser light at 200 nm for more than 6 h is the most important step for obtaining the generation of light at a wavelength of 160 nm.

关键词： vacuum ultraviolet light second harmonic generation sum frequency mixing

Comparison of the timing of spring phenological events between phenological garden trees and wild populations

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Journal of Plant Ecology 2024年第2期17卷 49-61页

作者： Calum J.Sweeney Fidelma Butler Astrid Wingler School of Biological Earth&Environmental Sciences and Environmental Research InstituteUniversity College CorkDistillery FieldsNorth MallCork T23 TK30Ireland

Phenological research is engaged in monitoring the infuence of climate change on the natural *** International Phenological Gardens(IPG)network provides a valuable dataset of standardized tree phenology records dating back to the mid-20th *** make best use of this actively growing record,it is important to investigate how network data can be applied to predict the timing of phenological events in natural *** study compared clonally propagated IPG downy birch(Betula pubescens Ehrh.)and hazel(Corylus avellana L.)specimens of central European provenance to nearby wild populations at the western-most margin of the IPG network,in the south-west of *** addition to monitoring by trained scientists,observations by citizen scientists were *** order of the timing of phenological events among sites was consistent across 2 years,confrming reproducibility of the *** trees had the earliest *** leaf unfolding and *** fowering dates of the sites *** addition,leaf unfolding occurred later in the wild populations than expected from the temperature responses of the *** and *** IPG *** variation in phenology also exceeded the historical change observed at the IPG site,suggesting a potential genetic basis for climate *** circumference,refecting the age-dependent increase in tree size,was found to infuence *** phenology,with earlier timing of phenological events in larger *** fnding highlights tree size as an important consideration in the management of phenological gardens and tree phenology research in general.

关键词： citizen science downy birch(Betula pubescens) hazel(Corylus avellana) phenological garden spring phenology tree size

Radiative loss of coherence in free electrons:a long-range quantum phenomenon

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Light(Science & Applications) 2024年第2期13卷 294-301页

作者： Cruz I.Velasco Valerio Di Giulio F.Javier García de Abajo ICFO-Institut de Ciencies Fotoniques The Barcelona Institute of Science and Technology08860Castelldefels(Barcelona)Spain ICREA-InstitucióCatalana de Recerca i Estudis Avançats Passeig Lluís Companys 2308010BarcelonaSpain

Quantum physics rules the dynamics of small objects as they interact over microscopic length ***,quantum correlations involving macroscopic distances can be observed between entangled photons as well as in atomic gases and matter waves at low *** long-range nature of the electromagnetic coupling between charged particles and extended objects could also trigger quantum phenomena over large ***,we reveal a manifestation of quantum mechanics that involves macroscopic distances and results in a nearly complete depletion of coherence associated with which-way free-electron interference produced by electron-radiation coupling in the presence of distant extended *** is a ubiquitous effect that we illustrate through a rigorous theoretical analysis of a two-path electron beam interacting with a semi-infinite metallic plate and find the inter-path coherence to vanish proportionally to the path separation at zero temperature and exponentially at finite *** investigated regime of large distances originates in the coupling of the electron to radiative modes assisted by diffraction at material structures but without any involvement of material *** the fundamental interest of this macroscopic quantum phenomenon,our results suggest an approach to measuring the vacuum temperature and nondestructively sensing the presence of distant objects.

关键词： temperature quantum macroscopic

Targeting the extracellular matrix for NF1-associated neurofibroma treatment

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Chinese Journal of Plastic and Reconstructive Surgery 2024年第2期6卷 87-93页

作者： Chunhui Jiang NHC Key Laboratory of Cell Transplantation First Affiliated Hospital of Harbin Medical University23 Youzheng StreetHarbin 150001HeilongjiangChina

Neurofibromatosis type 1(NF1)is one of the most common genetic disorders that predisposes patients to benign and malignant tumors of the peripheral nervous *** and cutaneous neurofibromas are NF1-associated benign *** their benign nature,they can cause tremendous morbidity in patients with *** drug options are limited to the MEK inhibitor,selumetinib,which is the only approved drug for pediatric patients with plexiform *** strategies have substantial therapeutic potential for NF1-associated *** review discusses the fibrotic features of plexiform and cutaneous neurofi-bromas focusing on the pathological composition of the extracellular *** also highlights the core pathways implicated in the biochemical and biophysical regulation of the extracellular matrix remodeling in tumor imitation and ***,this review provides a brief outlook on how exploring novel vulnerabilities residing in the aberrant extracellular matrix and their underlying pathways can benefit the treatment of NF1-associated neurofibromas.

关键词： Neurofibromatosis type 1 Cutaneous neurofibroma Plexiform neurofibroma Fibrosis Extracellular matrix Basement membrane

Recent Advances in the Synthesis and Polymerization of New CO_(2)-Based Cyclic

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Chinese Journal of Chemistry 2024年第4期42卷 430-443页

作者： Matteo Lanzi Arjan W.Kleij Institute of Chemical Research of Catalonia(ICIQ) The Barcelona Institute of Science and Technology(BIST)Av.Països Catalans 1643007 TarragonaSpain Catalan Institute of Research and Advanced Studies(ICREA) Pg.Lluís Companys 2308010 BarcelonaSpain

Carbon dioxide can be converted into functional heterocycles known as cyclic carbonates,whose recent reactivity has been expanded towards the formation of tailor-made engineering *** minireview gives an overview of the most topical developments in this area with a special focus on the synthetic methods employed to prepare these CO_(2)based *** addition,their application potential in the area of polymer science using a variety of polymerization techniques is discussed that have in common the ring-opening of the carbonate *** perspectives are provided that provide impetus for the scientific communities aligning research to the use of sustainable processes for polymers from recyclable carbon sources such as CO_(2).

关键词： Carbon dioxide Cyclic carbonates Functional macromolecules Heterocycles Polycarbonates Recycling Ring opening polymerization

Non-convex optimization for inverse problem solving in computer-generated holography

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Light(Science & Applications) 2024年第8期13卷 1464-1486页

作者： Xiaomeng Sui Zehao He Daping Chu Liangcai Cao Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Engineering Centre for Photonic Devices and SensorsUniversity of Cambridge9 JJ Thomson AvenueCambridge CB30FAUK Cambridge University Nanjing Centre of Technology and Innovation 23 Rongyue RoadJiangbei New AreaNanjing 210000China

Computer-generated holography is a promising technique that modulates user-defined wavefronts with digital *** appropriate holograms with faithful reconstructions is not only a problem closely related to the fundamental basis of holography but also a long-standing challenge for researchers in general fields of *** the exact solution of a desired hologram to reconstruct an accurate target object constitutes an ill-posed inverse *** general practice of single-diffraction computation for synthesizing holograms can only provide an approximate answer,which is subject to limitations in numerical *** non-convex optimization algorithms are thus designed to seek an optimal solution by introducing different constraints,frameworks,and ***,we overview the optimization algorithms applied to computer-generated holography,incorporating principles of hologram synthesis based on alternative projections and gradient descent *** is aimed to provide an underlying basis for optimized hologram generation,as well as insights into the cuttingedge developments of this rapidly evolving field for potential applications in virtual reality,augmented reality,head-up display,data encryption,laser fabrication,and metasurface design.

关键词： optimization convex inverse