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Photonics Research 2020年第8期8卷 1260-1267页

作者： RISHENG CHENG SIHAO WANG CHANG-LING ZOU hong x.tang Department of Electrical Engineering Yale UniversityNew HavenConnecticut 06511USA Department of Optics University of Science and Technology of ChinaHefei 230026China

Despite very efficient superconducting nanowire single-photon detectors(SNSPDs)reported recently,combining their other performance advantages such as high speed and ultralow timing jitter in a single device still remains *** this work,we present a perfect absorber model and the corresponding detector design based on a micrometer-long NbN nanowire integrated with a 2D photonic crystal cavity of ultrasmall mode volume,which promises simultaneous achievement of near-unity absorption,gigahertz counting rates,and broadband optical response with a 3 dB bandwidth of 71 *** to previous stand-alone meandered and waveguideintegrated SNSPDs,this perfect absorber design addresses the trade space in size,efficiency,speed,and bandwidth for realizing large on-chip single-photon detector arrays.

关键词： absorber perfect high

Positive definiteness of real quadratic forms resulting from the variable-step L1-type approximations of convolution operators

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Science China Mathematics 2024年第2期67卷 237-252页

作者： hong-Lin Liao Tao tang Tao Zhou School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Division of Science and Technology BNU-HKBU United International CollegeZhuhai 519087China SUSTech International Center for Mathematics Shenzhen 518055China NCMIS&LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The positive definiteness of real quadratic forms with convolution structures plays an important rolein stability analysis for time-stepping schemes for nonlocal operators. In this work, we present a novel analysistool to handle discrete convolution kernels resulting from variable-step approximations for convolution *** precisely, for a class of discrete convolution kernels relevant to variable-step L1-type time discretizations, weshow that the associated quadratic form is positive definite under some easy-to-check algebraic conditions. Ourproof is based on an elementary constructing strategy by using the properties of discrete orthogonal convolutionkernels and discrete complementary convolution kernels. To our knowledge, this is the first general result onsimple algebraic conditions for the positive definiteness of variable-step discrete convolution kernels. Using theunified theory, we obtain the stability for some simple nonuniform time-stepping schemes straightforwardly.

关键词： discrete convolution kernels positive definiteness variable time-stepping orthogonal convolution kernels complementary convolution kernels

Distributed algorithm for solving variational inequalities over time-varying unbalanced digraphs

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Control Theory and Technology 2024年第3期22卷 431-441页

作者： Yichen Zhang Yutao tang Zhipeng Tu Yiguang hong School of Artificial Intelligence Beijing University of Posts and TelecommunicationsBeijing 100876China Network Technology Laboratory Huawei Technologies Co.Ltd.Beijing 100095China Department of Control Science and Engineering Tongji UniversityShanghai 200092China Shanghai Research Institute for Intelligent Autonomous Systems Tongji UniversityShanghai 200092China

In this paper,we study a distributed model to cooperatively compute variational inequalities over time-varying directed ***,each agent has access to a part of the full mapping and holds a local view of the global set *** virtue of an auxiliary vector to compensate the graph imbalance,we propose a consensus-based distributed projection algorithm relying on local computation and communication at each *** show the convergence of this algorithm over uniformly jointly strongly connected unbalanced digraphs with nonidentical local *** also provide a numerical example to illustrate the effectiveness of our algorithm.

关键词： Variational inequality Distributed computation Multi-agent system Weight-unbalanced graph

A passive sampler for synchronously measuring inorganic and organic pollutants in sediment porewater:Configuration and field application

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Journal of Environmental Sciences 2024年第2期136卷 201-212页

作者： Pei Lei Mingying Chen Nan Rong Wenzhong tang hong Zhang School of Environment Nanjing Normal UniversityNanjing 210023China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510530China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control Guangzhou 510530China University of Chinese Academy of Sciences Beijing 100049China

In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better *** this study,a passive sampler,consisting of an“I-shaped”supporting frame and inorganic/organic sampling units,incorporating equilibrium dialysis theory and kinetic/equilibrium sorption principle,was developed for the synchronous measurement of inorganic(e.g.,phosphorus and metal(loid)s)and organic pollutants(e.g.,parent and substituted PAHs).The equilibrium time and sampling rates were explored in laboratory tests to support in situ *** of pollutants in porewater within a vertical resolution of centimeters,i.e.,1 cm and 2 cm for inorganic and organic pollutants,respectively,were obtained by field deployment of the sampler for further estimation of diffusive fluxes across the sediment-water *** results suggested that the role of sediments for a specific pollutant may change(e.g.,from“sink”to“source”)during the sampling *** study demonstrated the feasibility of synchronous measurement of inorganic and organic pollutants in sediment porewater by the passive *** addition,it provided new insight for further investigation into the combined pollution effects of various pollutants in sediments.

关键词： Passive sampling Bioavailability Polycyclic aromatic hydrocarbons Combined pollution Diffusive flux

Video caching and scheduling with edge cooperation

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Digital Communications and Networks 2024年第2期10卷 450-460页

作者： Zhidu Li Fuxiang Li Tong tang hong Zhang Jin Yang School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Advanced Network and Intelligent Connection Technology Key Laboratory of Chongqing Education Commission of China Chongqing400065China Key Laboratory of Ubiquitous Sensing and Networking in Chongqing Chongqing400065China

In this paper,we explore a distributed collaborative caching and computing model to support the distribution of adaptive bit rate video *** aim is to reduce the average initial buffer delay and improve the quality of user *** the difference between global and local video popularities and the time-varying characteristics of video popularity,a two-stage caching scheme is proposed to push popular videos closer to users and minimize the average initial buffer *** on both long-term content popularity and short-term content popularity,the proposed caching solution is decouple into the proactive cache stage and the cache update *** the proactive cache stage,we develop a proactive cache placement algorithm that can be executed in an off-peak *** the cache update stage,we propose a reactive cache update algorithm to update the existing cache policy to minimize the buffer *** results verify that the proposed caching algorithms can reduce the initial buffer delay efficiently.

关键词： Video service Distributed and collaborative caching Long-term popularity Short-term popularity

Morphology Study for GeV Emission of Nearby Supernova Remnant G332.5-5.6

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Research in Astronomy and Astrophysics 2024年第4期24卷 134-140页

作者： Ming-hong Luo Qing-Wen tang xiu-Rong Mo Department of Physics School of Physics and Materials ScienceNanchang UniversityNanchang 330031China

A spatial template is important to study nearby supernova remnants(SNRs).For SNR G332.5-5.6,we report a Gaussian disk with a radius of about 1°.06 to be a potential good spatial model in the γ-ray *** this new Gaussian disk,its GeV lightcurve shows a significant variability of about seven *** γ-ray observations of this SNR could be explained well either by a leptonic model or a hadronic model,in which a flat spectrum for the ejected electrons/protons is required.

关键词： ISM:supernova remnants gamma rays:ISM

Immunobiology of COVID-19: Mechanistic and therapeutic insights from animal models

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Zoological Research 2024年第4期45卷 747-766页

作者： hong-Yi Zheng Tian-Zhang Song Yong-tang Zheng State Key Laboratory of Genetic Evolution&Animal Models KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesCenter for Biosafety Mega-ScienceKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China National Resource Center for Non-Human Primates National Research Facility for Phenotypic&Genetic Analysis of Model Animals(Primate Facility)Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650107China

The distribution of the immune system throughout the body complicates in vitro assessments of coronavirus disease 2019(COVID-19)immunobiology,often resulting in a lack of reproducibility when extrapolated to the whole ***,developing animal models is imperative for a comprehensive understanding of the pathology and immunology of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)*** review summarizes current progress related to COVID-19 animal models,including non-human primates(NHPs),mice,and hamsters,with a focus on their roles in exploring the mechanisms of immunopathology,immune protection,and long-term effects of SARS-CoV-2 infection,as well as their application in immunoprevention and immunotherapy of SARS-CoV-2 *** among these animal models and their specific applications are also highlighted,as no single model can fully encapsulate all aspects of *** effectively address the challenges posed by COVID-19,it is essential to select appropriate animal models that can accurately replicate both fatal and non-fatal infections with varying courses and *** animal model libraries and associated research tools is key to resolving the global COVID-19 pandemic,serving as a robust resource for future emerging infectious diseases.

关键词： SARS-CoV-2 COVID-19 Animal models Infection immunology Immunotherapy

Predicting submerged vegetation drag with a machine learning-based method

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Journal of Hydrodynamics 2024年第3期36卷 534-545页

作者： Meng-yang Liu hong-wu tang Sai-yu Yuan Jing Yan College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources Hohai UniversityNanjing210098China

Accurate estimation of the drag forces generated by vegetation stems is crucial for the comprehensive assessment of the impact of aquatic vegetation on hydrodynamic processes in aquatic *** coupling relationship between vegetation layer flow velocity and vegetation drag makes precise prediction of submerged vegetation drag forces particularly *** present study utilized published data on submerged vegetation drag force measurements and employed a genetic programming(GP)algorithm,a machine learning technique,to establish the connection between submerged vegetation drag forces and flow and vegetation *** using the bulk velocity,U,as the reference velocity scale to define the drag coefficient,C_(d),and stem Reynolds number,the GP runs revealed that the drag coefficient of submerged vegetation is related to submergence ratio(H^(*)),aspect ratio(d^(*)),blockage ratio(ψ^(*)),and vegetation density(λ).The relation between vegetation stem drag forces and flow velocity is implicitly embedded in the definition of C_(d).Comparisons with experimental drag force measurements indicate that using the bulk velocity as the reference velocity,as opposed to using the vegetation layer average velocity,U_(v),eliminates the need for complex iterative processes to estimate U_(v)and avoids introducing additional errors associated with U_(v)*** approach significantly enhances the model’s predictive capabilities and results in a simpler and more user-friendly formula expression.

关键词： Drag coefficient genetic programming algorithm submerged vegetation flow resistance cylinder array

Parametric down-conversion photon-pair source on a nanophotonic chip

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Light(Science & Applications) 2016年第1期5卷 96-103页

作者： xiang Guo Chang-ling Zou Carsten Schuck Hojoong Jung Risheng Cheng hong x tang Department of Electrical Engineering Yale UniversityNew HavenCT 06511USA

Quantum-photonic chips,which integrate quantum light sources alongside active and passive optical elements,as well as singlephoton detectors,show great potential for photonic quantum information processing and quantum *** semiconductor nanofabrication processes allow for scaling such photonic integrated circuits to on-chip networks of increasing ***-order nonlinear materials are the method of choice for generating photonic quantum states in the overwhelming majority of linear optic experiments using bulk components,but integration with waveguide circuitry on a nanophotonic chip proved to be ***,we demonstrate such an on-chip parametric down-conversion source of photon pairs based on second-order nonlinearity in an aluminum-nitride microring *** show the potential of our source for quantum information processing by measuring the high visibility anti-bunching of heralded single photons with nearly ideal state *** down-conversion source yields measured coincidence rates of 80 Hz,which implies MHz generation rates of correlated photon *** noise performance is demonstrated by measuring high coincidence-to-accidental *** generated photon pairs are spectrally far separated from the pump field,providing great potential for realizing sufficient on-chip filtering and monolithic integration of quantum light sources,waveguide circuits and single-photon detectors.

关键词： nanofabrication quantum photonic chip second-order nonlinear material single-photon source

Effect of bariatric surgery on metabolism in diabetes and obesity comorbidity:Insight from recent research

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World Journal of Diabetes 2024年第4期15卷 586-590页

作者： Hui-hong tang Dong Wang Cheng-Chun tang Department of Cardiology Zhongda HospitalSoutheast UniversityNanjing 210009Jiangsu ProvinceChina School of Medicine Southeast UniversityNanjing 210009Jiangsu ProvinceChina

Obesity is a prevalent cause of diabetes mellitus(DM)and is a serious danger to human *** 2 DM(T2DM)mostly occurs along with *** obesity-induced DM is caused by an excessive long-term diet and surplus *** surgery can improve the symptoms of T2DM in some obese *** different types of bariatric surgery may have different *** are some models built by researchers to discuss the surgical procedures’effects on me-tabolism in diabetes animal models and diabetes *** is high time to conclude all this effects and recommend procedures that can better improve metabolism.

关键词： Bariatric surgery Obesity Diabetes Animal models Diabetes patients