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Energy Stable Nodal DG Methods for Maxwell’s Equations of Mixed-Order Form in Nonlinear Optical Media

Communications on Applied Mathematics and Computation 2024年第1期6卷 30-63页

作者： Maohui lyu Vrushali A.Bokil Yingda Cheng Fengyan Li State Key Laboratory of Scientific and Engineering Computing(LSEC) Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing100190China Department of Mathematics College of ScienceOregon State UniversityCorvallisOR97331USA Department of Mathematics Michigan State UniversityEast LansingMI48824USA Department of Computational Mathematics Science and EngineeringMichigan State UniversityEast LansingMI48824USA Department of Mathematical Sciences Rensselaer Polytechnic InstituteTroyNY12180USA

In this work,we develop energy stable numerical methods to simulate electromagnetic waves propagating in optical media where the media responses include the linear Lorentz dispersion,the instantaneous nonlinear cubic Kerr response,and the nonlinear delayed Raman molecular vibrational *** the first-order PDE-ODE governing equations considered previously in Bokil et al.(J Comput Phys 350:420–452,2017)and lyu et al.(J Sci Comput 89:1–42,2021),a model of mixed-order form is adopted here that consists of the first-order PDE part for Maxwell’s equations coupled with the second-order ODE part(i.e.,the auxiliary differential equations)modeling the linear and nonlinear dispersion in the *** main contribution is a new numerical strategy to treat the Kerr and Raman nonlinearities to achieve provable energy stability property within a second-order temporal discretization.A nodal discontinuous Galerkin(DG)method is further applied in space for efficiently handling nonlinear terms at the algebraic level,while preserving the energy stability and achieving high-order *** with d_(E)as the number of the components of the electric field,only a d_(E)×d_(E)nonlinear algebraic system needs to be solved at each interpolation node,and more importantly,all these small nonlinear systems are completely decoupled over one time step,rendering very high parallel *** evaluate the proposed schemes by comparing them with the methods in Bokil et al.(2017)and lyu et al.(2021)(implemented in nodal form)regarding the accuracy,computational efficiency,and energy stability,by a parallel scalability study,and also through the simulations of the soliton-like wave propagation in one dimension,as well as the spatial-soliton propagation and two-beam interactions modeled by the two-dimensional transverse electric(TE)mode of the equations.

关键词： Maxwell’s equations Kerr and Raman Discontinuous Galerkin method Energy stability

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The Impact of New Regulations on Prevention and Control of E-Cigarettes on Adolescents in Middle Schools—A City in China,2022–2023

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China CDC weekly 2024年第14期6卷 289-293页

作者： Meng lyu Wenlong Lu Lanhua Zou Jingfan Xiong Jie Yang Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina Shenzhen Center for Chronic Disease Control Shenzhen CityGuangdong ProvinceChina

What is already known about this topic?To protect the health of young people from the harmful impacts of electronic cigarettes(e-cigarettes),China has enacted various policies and regulations since *** of October 1,2022,the Electronic Cigarette Management Measures were put into *** prohibited the sale of flavored e-cigarettes,permitting only those of plain tobacco flavor to be *** is added by this report?The illegal market for flavored e-cigarettes,often disguised as milk tea cups,cola cans,and violent bear images,continues to *** is an increased need to bolster support for the prohibition of flavored e-cigarettes and enhance public awareness of associated *** are the implications for public health practice?To advance the health of China’s youth,it is crucial to improve the implementation and understanding of ecigarette policies and guidelines.

关键词： Middle Impact plain

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Equalization Reconstruction Algorithm Based on Reference Signal Frequency Domain Block Joint for DTMB-Based Passive Radar

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Journal of Beijing Institute of Technology 2024年第1期33卷 41-53页

作者： Shuai Ma Zeqi Yang Hua Zhang Yiheng Liu Xiaode lyu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Microwave Imaging Technology Beijing 100190China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China.

Channel equalization plays a pivotal role within the reconstruction phase of passive radar reference *** the context of reconstructing digital terrestrial multimedia broadcasting(DTMB)signals for low-slow-small(LSS)target detection,a novel frequency domain block joint equalization algorithm is presented in this *** the DTMB signal frame structure and channel multipath transmission characteristics,this article adopts a unconventional approach where the delay and frame structure of each DTMB signal frame are reconfigured to create a circular convolution block,facilitating concurrent fast Fourier transform(FFT)*** equalization,an inverse fast Fourier transform(IFFT)-based joint output and subsequent data reordering are executed to finalize the equalization process for the DTMB *** and measured data confirm that this algorithm outperforms conventional techniques by reducing signal errors rate and enhancing real-time *** passive radar LSS detection,it effectively suppresses multipath and noise through frequency domain equalization,reducing false alarms and improving the capabilities of weak target detection.

关键词： passive radar frequency domain equalization reference signal reconstruction digital terrestrial multimedia broadcasting(DTMB)

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C—F Bond Insertion into Indoles with CHBr_(2)F:An Efficient Method to Synthesize Fluorinated Quinolines and Quinolones

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Chinese Journal of Chemistry 2024年第10期42卷 1128-1132页

作者： Chao Li Lei Chen Hongye Wang Zixi Yan Bin lyu Weiping lyu Changwei Jiang Dehua Lu Jiaxing Li Ning Jiao Song Song State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityXue Yuan Rd.38Beijing 100191China

A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)*** simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and *** mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.

关键词： Skeleton edit Fluorocarbene Ring expansion Quinoline Quinolone

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In-situ observation of structural evolution of single-atom catalysts:From synthesis to catalysis

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ChemPhysMater 2024年第1期3卷 24-35页

作者： Lei Wang Shuyuan lyu Shuohao Li School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China School of Art and Design Huaiyin Institute of TechnologyHuaian 223003China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China

Atomically dispersed single-atom catalysts(SACs)have been extensively studied over the past decade because of their high atom utilization efficiencies and specific *** numerous strategies have been proposed to obtain SACs with high densities and stabilities,the transformation mechanism that occurs during the reaction is still *** review summarizes the structural evolution of SACs in the preparation process and reaction with various electron microscopy techniques at atomic scale under environmental *** state-of-the-art environmental electron microscopy studies on SACs mainly focus on porous carbons,metals or metal oxides,and some specific composite *** dynamic evolution of SACs under various reaction conditions is also investigated in this ***,we highlight the challenges and drawbacks of the current studies and the prospects for the future exploration of SACs with environmental strategies.

关键词： Single-atom catalysts Structural transformation Atomization Environmental electron microscope

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Long-Term Performance and Microstructural Characterization of Dam Concrete in the Three Gorges Project

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Engineering 2024年第2期33卷 237-262页

作者： Chen lyu Cheng Yu Chao Lu Li Pan Wenwei Li Jiaping Liu School of Materials Science and Engineering Southeast UniversityNanjing 211189China State Key Laboratory of High Performance Civil Engineering Materials Sobute New Materials Co.Ltd.Nanjing 211103China China Three Gorges Corporation Wuhan 430010China

This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the Three Gorges *** mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over ***,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 ***,curing and long-term exposure to the local natural environment reduced the frost *** analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few *** obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic *** dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later *** concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind *** this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the Three Gorges Dam after 17 ***-term exposure to an actual service environment may lead to microstructural degradation of the concrete ***,the retained long-term dam concrete samples need to be further researched to

关键词： Three Gorges Dam Long-term performance Microstructural analysis Moderate-heat cement Fly ash

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Determination of the critical rainfall of runoff-initiated debris flows by the perspective of physical mechanics and Shields stress

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Journal of Mountain Science 2024年第4期21卷 1160-1173页

作者： MA Chao ZHU Yongtai LU Lu DU Cui lyu Liqun DONG Jie School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China Beijing Institute of Geological Hazard Prevention Beijing 100120China School of Software Engineering Chengdu University of Information TechnologyChengdu610225China Civil and Environmental Engineering Department Clarkson UniversityNY 13699USA

The critical rainfall of runoff-initiated debris flows is utmost importance for local early hazard *** paper presents research on the critical rainfall of runoff-initiated debris flows through comparisons between slope gradients and three key factors,including topographic contributing area,dimensionless discharge,and Shields *** rainfall amount was estimated by utilizing in-situ rainfall records and a slope-dependent Shields stress model was *** created model can predict critical Shields stress more accurately than the other two ***,a new dimensionless discharge equation was proposed based on the corresponding discharge-gradient *** new equation,along with factors such as contributing area above bed failure sites,channel width,and mean diameter of debris flow deposits,predicts a smaller rainfall amount than the in-situ measured *** the slope-dependent Shields stress model performs well and the estimated rainfall amount is lower than the in-situ records,the sediment initiation in the experiments falls within sheet flow regime due to a large Shields ***,further sediment initiation experiments at a steeper slope range are expected in the future to ensure that the sediment transport belongs to mass failure regime characterized by a low level of Shields ***,a more accurate hazard forecast on the runoff-initiated debris flow holds promise when the corresponding critical slope-dependent dimensionless discharge of no motion,fluvial sediment transport,mass flow regime,and sheet flow regime are considered.

关键词： Infinite slope stability Shields stress Contributing area-slope gradient Rainfall back estimation

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Architecture Design of Protocol Controller Based on Traffic-Driven Software Defined Interconnection

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Chinese Journal of Electronics 2024年第2期33卷 362-370页

作者： Peijie LI Jianliang SHEN Ping lyu Chunlei DONG Ting CHEN Information Engineering University

To solve the problems of redundant logic resources and poor scalability in protocol controller circuits among communication networks, we propose a traffic-driven software defined interconnection(TSDI) *** unified software defined interconnection interface standards and the normalized interconnection topology are designed to implement the architecture of TSDI-based protocol controller. The key indicators of power, performance and area(PPA) can be realized while resolving the flexible interconnection of the controller. We designed a TSDI-based Rapid IO controller as an example. Compared to traditional designs, the design could achieve more protocol scalability,and Rapid IO protocol standards of Gen4 could be supported directly. The key PPA indicators, such as a lower delay of 56.1 ns and more than twice throughput of 98.1 Gbps, were achieved at the cost of a 23.4% area increase.

关键词： Protocols Software design Scalability Integrated circuit interconnections Process control Computer architecture Throughput

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A Novel Clutter Suppression Algorithm for Low-Slow-Small Targets Detecting Based on Sparse Adaptive Filtering

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Journal of Beijing Institute of Technology 2024年第1期33卷 54-64页

作者： Zeqi Yang Shuai Ma Ning Liu Kai Chang Xiaode lyu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Microwave Imaging Technology Beijing 100190China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China Northern Institute of Electronic Equipment Beijing 100083China

Passive detection of low-slow-small(LSS)targets is easily interfered by direct signal and multipath clutter,and the traditional clutter suppression method has the contradiction between step size and convergence *** this paper,a frequency domain clutter suppression algorithm based on sparse adaptive filtering is *** pulse compression operation between the error signal and the input reference signal is added to the cost function as a sparsity constraint,and the criterion for filter weight updating is improved to obtain a purer echo *** the same time,the step size and penalty factor are brought into the adaptive iteration process,and the input data is used to drive the adaptive changes of parameters such as step *** proposed algorithm has a small amount of calculation,which improves the robustness to parameters such as step size,reduces the weight error of the filter and has a good clutter suppression performance.

关键词： passive radar interference suppression sparse representation adaptive filtering

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Optimization of tracheoesophageal fistula model established with Tshaped magnet system based on magnetic compression technique

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World Journal of Gastroenterology 2024年第16期30卷 2272-2280页

作者： Miao-Miao Zhang Jian-Qi Mao Lin-Xin Shen Ai-Hua Shi Xin lyu Jia Ma Yi lyu Xiao-Peng Yan Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Shaanxi Provincial Key Laboratory of Magnetic Medicine The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Zonglian College Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina National Local Joint Engineering Research Center for Precision Surgery&Regenerative Medicine The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Department of Pulmonary and Critical Care Medicine The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004Shaanxi ProvinceChina Department of Surgical Oncology Shaanxi Provincial People’s HospitalXi’an 710068Shaanxi ProvinceChina

BACKGROUND The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula(TEF),but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model *** designed a Tshaped magnet system to overcome these problems and verified its effectiveness via animal *** To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle *** Twelve beagles were randomly assigned to groups in which magnets of the Tshaped scheme(study group,n=6)or normal magnets(control group,n=6)were implanted into the trachea and esophagus separately under *** time,operation success rate,and accidental injury were *** operation,the presence and timing of cough and the time of magnet shedding were *** in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing,and gross specimens of TEFs were *** in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery,and gross specimens were *** size was measured in all animals,and then harvested fistula specimens were examined by hematoxylin and eosin(HE)and Masson trichrome *** The operation success rate was 100%for both *** time did not differ between the study group(5.25 min±1.29 min)and the control group(4.75 min±1.70 min;P=0.331).No bleeding,perforation,or unplanned magnet attraction occurred in any animal during the *** the early postoperative period,all dogs ate freely and were generally in good *** in the control group had severe cough after drinking water at 6-9 d after surgery.X-ray indicated that the magnets had entered the stomach,and gastroscopy showed TEF *** specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm±1.29 mm(range,3.52-6.56 mm).HE and Masson trichrome staining showed s

关键词： Magnetic surgery Magnetic compression technique Tracheoesophageal fistula Magnet Animal model Beagles

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