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Super-resolution diffractive neural network for alloptical direction of arrival estimation beyond diffraction limits

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Light(Science & Applications) 2024年第8期13卷 1602-1614页

作者： Sheng gao Hang Chen Yichen Wang Zhengyang Duan Haiou Zhang zhi Sun Yuan Shen Xing lin Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Wireless sensing of the wave propagation direction from radio sources lays the foundation for communication,radar,navigation,***,the existing signal processing paradigm for the direction of arrival estimation requires the radio frequency electronic circuit to demodulate and sample the multichannel baseband signals followed by a complicated computing process,which places the fundamental limit on its sensing speed and energy ***,we propose the super-resolution diffractive neural networks(S-DNN)to process electromagnetic(EM)waves directly for the DOA estimation at the speed of *** multilayer meta-structures of S-DNN generate super-oscillatory angular responses in local angular regions that can perform the all-optical DOA estimation with angular resolutions beyond the diffraction *** spatial-temporal multiplexing of passive and reconfigurable S-DNNs is utilized to achieve high-resolution DOA estimation over a wide field of *** S-DNN is validated for the DOA estimation of multiple radio sources over 5 GHz frequency bandwidth with estimation latency over two to four orders of magnitude lower than the state-of-the-art commercial devices in *** results achieve the angular resolution over an order of magnitude,experimentally demonstrated with four times,higher than diffraction-limited *** also apply S-DNN’s edge computing capability,assisted by reconfigurable intelligent surfaces,for extremely low-latency integrated sensing and communication with low power *** work is a significant step towards utilizing photonic computing processors to facilitate various wireless sensing and communication tasks with advantages in both computing paradigms and performance over electronic computing.

关键词： beyond optical network

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Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： zhi-lin Shen Jian-Jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

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宋新庄选煤厂溜槽优化改造实践

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煤炭加工与综合利用 2024年第6期 18-21页

作者：崇立芹张立忠任志国高智林武跃文徐鹏飞蒋超杨世坤北京中煤阳光矿业技术有限公司北京100013 宁夏聚盛乾诚技术有限公司盐池分公司宁夏吴忠751500

阐述了宋新庄选煤厂部分溜槽在使用过程出现物料堵塞、噪音过高、磨损严重、对下游设备冲击力大等问题。经过不断优化设计,对弛张筛筛前溜槽、原煤带式输送机副溜槽、矸石带式输送机机头溜槽、煤泥刮板输送机卸料溜槽等进行了改造。改... 详细信息

阐述了宋新庄选煤厂部分溜槽在使用过程出现物料堵塞、噪音过高、磨损严重、对下游设备冲击力大等问题。经过不断优化设计,对弛张筛筛前溜槽、原煤带式输送机副溜槽、矸石带式输送机机头溜槽、煤泥刮板输送机卸料溜槽等进行了改造。改造后溜槽寿命得以延长,煤流系统更加顺畅,职工工作环境得以改善,劳动强度降低,现场安全标准化水平上了新台阶,且节约了维护成本,保障了选煤厂的安全高效生产。

关键词：选煤厂溜槽优化改造安全标准化维护成本

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The effects of cool materials,façade orientation,and morphological parameters on energy consumption at the residential neighborhood scale

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Building Simulation 2024年第4期17卷 525-542页

作者： Fusuo Xu Dongdong Tian zhi gao Jianshun Jensen Zhang Department of Mechanical and Aerospace Engineering Syracuse UniversitySyracuseNY13210USA School of Architecture and Urban Planning Nanjing University22 Hankou RoadNanjingJiangsu Province210093China

Building surface cool materials are novel materials that can reduce urban heat island intensity and decrease building energy *** study investigated the impact of radiative properties of materials,façade orientation,and morphological parameters on energy consumption in six typical residential neighborhoods in Nanjing,*** neighborhood energy consumption of 16 application schemes considering the façade orientation factor is compared to determine the best energy-saving *** and annual energy-saving rates,savings in electricity costs,and the price ceiling for materials per unit area are *** results show that for low-rise buildings,using cool materials only on the roof can reduce the annual energy consumption by 1%.When cool or super cool materials are also used on the building façade,the annual energy saving rate can be up to 3.4%and 4.3%,*** cool materials on the south façade of buildings is not recommended due to significant heat loss in *** savings in electricity costs and the price ceiling for materials per unit area,the price of cool and super cool materials should be less than 3.0 and 3.7 RMB/m2,respectively,assuming a lifespan of eight years in Nanjing.

关键词： cool materials building energy saving neighborhood morphology façade orientation

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Dual-curvilinear beam enabled tunable manipulation of high-and low-refractive-index particles

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Photonics Research 2024年第7期12卷 1427-1436页

作者： ZHENG YUAN CHENCHEN ZHANG YUAN gao WENXIANG YAN XIAN LONG zhi-CHENG REN XI-lin WANG JIANPING DING HUI-TIAN WANG National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics Nanjing 210093China

We present an innovative approach for the simultaneous agile manipulation of high-refractive-index(HRI) and low-refractive-index(LRI) particles. Our method involves introducing a dual-curvilinear optical vortex beam(DC-OVB) generated by superimposing a pair of curved beams: HRI and LRI particles are controlled by the bright curve and the dark channel between the two curves, respectively. The proposed DC-OVB provides customizable motion paths and velocities for both LRI and HRI particles. Each curve of the DC-OVB can support a distinct orbital flow density(OFD), enabling the application of torques to HRI and LRI particles, guiding them to orbit along specified trajectories and prompting them to execute various curvilinear motions simultaneously,including curvilinear movement, revolution, and rotation.

关键词： tunable refractive beam

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Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang Wu Jia Qu lin-zhi Wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

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Spatial covariant gravity with two degrees of freedom in the presence of an auxiliary scalar field:Perturbation analysis

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Chinese Physics C 2024年第8期48卷 198-212页

作者： zhi-Chao Wang Xian gao School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

We investigate a class of gravity theories respecting only spatial covariance,termed spatially covariant gravity,in the presence of an auxiliary scalar *** examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom,allowing only two tensorial degrees of freedom to *** of strict constraint analysis,in this paper,we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological *** with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode,we derive the condition to remove its kinetic term,thus ensuring that no scalar mode *** an application of the general condition,we study a polynomial-type Lagrangian as a concrete example,in which all monomials are spatially covariant scalars containing two *** find that the auxiliary scalar field is essential,and new terms in the Lagrangian are *** analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.

关键词： modified gravity cosmological perturbation theory gravitational theory

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Precise Asymptotics in Limit Theorems for a Supercritical Branching Process with Immigration in a Random Environment

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1850-1874页

作者： Chun Mao HUANG Rui ZHANG zhi Qiang gao Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

Let(Zn)be a supercritical branching process with immigration in an independent and identically distributed random *** necessary moment conditions,we show the exact convergence rate in the central limit theorem on log Zn and establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its *** similar approach and with the help of a change of measure,we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

关键词： Branching process with immigration random environment central limit theorem large deviation

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Incentive Feedback Stackelberg Strategy in Mean-Field Type Stochastic Difference Games

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Journal of Systems Science & Complexity 2024年第4期37卷 1425-1445页

作者： gao Wenhui lin Yaning ZHANG Weihai School of Mathematics and Statistics Shandong University of TechnologyZibo 255000China College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

This paper designs an incentive Stackelberg strategy for the discrete-time stochastic systems with mean-field *** conditions for the existence of such a design are ***,the incentive strategy is obtained as a feedback form including the deviation of the state and its mathematical ***,the stability analysis is *** is found that the stability can be guaranteed by the *** addition,the specific algorithm is proposed and its effectiveness is checked by two examples.

关键词： Discrete-time mean-field stochastic systems incentive strategy Stackelberg game teamoptimal solution

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Severe pediatric COVID‑19:a review from the clinical and immunopathophysiological perspectives

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World Journal of Pediatrics 2024年第4期20卷 307-324页

作者： Yi‑Kan Sun Can Wang Pei‑Quan lin Lei Hu Jing Ye zhi‑Gang gao Ru lin Hao‑Min Li Qiang Shu Li‑Su Huang lin‑Hua Tan Children's Hospital Zhejiang University School of MedicineHangzhou 310052China The Second Affiliated Hospital Zhejiang University School of MedicineHangzhou 310030China Surgical Intensive Care Unit Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of General Surgery Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Cardiopulmonary and Extracorporeal Life Support Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Clinical Data Center Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Cardiac Surgery Children’s HospitalZhejiang University School of MedicineHangzhou 310052China National Clinical Research Center for Child Health Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Infectious Diseases Children’s HospitalZhejiang University School of MedicineHangzhou 310052China

Background Coronavirus disease 2019(COVID-19)tends to have mild presentations in ***,severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times,meriting further attention from ***,the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely *** sources A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed,Embase,and Wanfang *** keywords included“COVID-19 in children”,“severe pediatric COVID-19”,and“critical illness in children with COVID-19”.Results Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated *** respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations,while various forms of cardiovascular and neurological involvement may also be *** immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways,whose dysregulation in severe and critical diseases translates into adverse clinical *** inflammatory syndrome in children(MIS-C),a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure,denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric *** the considerable dissimilarities between the pediatric and adult immune systems,clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult *** Severe pediatric COVID-19 can affect multiple organ *** dysregulated immune pathways in severe COVID-19 shape the disease course,epitomize the vast functional diversity of the

关键词： Immunopathophysiology MIS-C Pediatric critical care Severe pediatric COVID-19

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