检索结果-南通市图书馆

Nuclear Science and Techniques 2024年第3期35卷 40-52页

作者： Ding-han Zhu Xiong Zhang Xiao-Qiang li Peng li Yan-Bin Wang Shuang Zhang State Key Laboratory of NBC Protection for Civilian Beijing 102205China

In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such *** pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric *** quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering *** proposed method is an improvement over the traditional analytical method that only computes direct-transmission *** traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo *** improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain ***,its computation time is 48,000 times faster than that of the Monte Carlo *** results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects.

关键词： High-altitude nuclear detonation Atmospheric transmission Pulsed X-rays Scattering correction Analytical method Monte Carlo method

Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 636-641页

作者： Jiao mu liufang Hao Zijue Wang Xuyang Fu Yusen li Fei Hao Hongmei Duan Zhaoyang Yang Xiaoguang li Beijing Key Laboratory for Biomaterials and Neural Regeneration School of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Neurobiology School of Basic Medical SciencesCapital Medical UniversityBeijingChina

Stroke can cause Wallerian degeneration in regions outside of the brain,particularly in the corticospinal *** investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke,we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal *** first used a routine,sensitive marker of axonal injury,amyloid precursor protein,to examine Wallerian degeneration of the corticospinal *** antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex,with no positive signal in distal parts of the corticospinal tract,at all time *** improve visualization of Wallerian degeneration,we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing *** this approach,we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after *** addition,microglia mobilized and activated early,from day 7 after stroke,but did not maintain a phagocytic state over ***,astrocytes showed relatively delayed mobilization and a moderate response to Wallerian ***,no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal *** conclusion,our data provide evidence for dynamic,pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.

关键词： corticospinal tract green fluorescent protein microglia spinal anterior horn cells stroke virus trace Wallerian degeneration

Analysis of level structure and monopole effects in Ca isotopes

在线全文

学校读者我要写书评

暂无评论

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-7页

作者： li, Jin Chen, Ai-Xi Jalili, Amir Wang, han-Kui Zhejiang Sci Tech Univ Sch Sci Hangzhou 310018 Peoples R China

Understanding the properties of nuclei near the double magic nucleus 40Ca is crucial for both nuclear theory and experiments. In this study, Ca isotopes were investigated using an extended pairing-plus-quadrupole model with monopole corrections. The negative-parity states of 44Ca were coupled with the intruder orbital g9/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$g_{9/2}$$\end{document} at 4 MeV. The values of E4+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E_{4+}$$\end{document}/E2+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E_{2+}$$\end{document} agree well with experimental trend from 42Ca to 50Ca, considering monopole effects between nu f7/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu f_{7/2}$$\end{document} and nu p3/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu p_{3/2}$$\end{document}(nu f5/2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu f_{5/2}$$\end{docume

关键词： Shell model Doubly magic Isotopes Monopole effects Level structure BETA-DECAY MODEL

A Local-Global Attention Fusion Framework With Tensor Decomposition for Medical Diagnosis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1536-1538页

作者： Peishu Wu han li liwei Hu Jirong Ge Nianyin Zeng Department of Instrumental and Electrical Engineering Xiamen UniversityFujian 361005China Key Research Laboratory of Osteoporosis Syndrome Genomics Fujian Academy of Chinese Medical SciencesFuzhou 350003China

Dear Editor,In this letter,a novel hierarchical fusion framework is proposed to address the imperfect data property in complex medical image analysis(MIA)*** particular,by combining the strengths of convolutional neural networks(CNNs)and transformers,the enhanced feature extraction,spatial modeling,and sequential context learning are realized to provide comprehensive insights on the complex data *** of information in different level is enabled via a multi-attention fusion mechanism,and the tensor decomposition methods are adopted so that compact and distinctive representation of the underlying and high-dimensional medical image features can be accomplished[1].It is shown from the evaluation results that the proposed framework is competitive and superior as compared with some other advanced algorithms,which effectively handles the imperfect property of inter-class similarity and intra-class differences in diseases,and meanwhile,the model complexity is reduced within an acceptable level,which benefits the deployment in clinic *** has assumed a pivotal role in numerous critical clinical scenarios,where sophisticated image analysis techniques have proven instrumental in augmenting medical decision-making,facilitating individualized therapeutic interventions,and enhancing patient prognostication[2]−[4].

关键词： handle image property

Intelligent UAV Based Energy Supply for 6G Wireless Powered IoT Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第9期21卷 321-337页

作者： Miao Jiansong Chen Haoqiang Wang Pengjie li Hairui Zhao Yan mu Junsheng Yan Shi School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,we develop a 6G wireless powered Internet of Things(IoT)system assisted by unmanned aerial vehicles(UAVs)to intelligently supply energy and collect data at the same *** our dual-UAV scheme,UAV-E,with a constant power supply,transmits energy to charge the IoT devices on the ground,whereas UAV-B serves the IoT devices by data collection as a base *** this framework,the system's energy efficiency is maximized,which we define as a ratio of the sum rate of IoT devices to the energy consumption of two UAVs during a fixed working *** the constraints of duration,transmit power,energy,and mobility,a difficult non-convex issue is presented by optimizing the trajectory,time duration allocation,and uplink transmit power of *** tackle the non-convex fractional optimization issue,we deconstruct it into three subproblems and we solve each of them iteratively using the descent method in conjunction with sequential convex approximation(SCA)approaches and the Dinkelbach *** simulation findings indicate that the suggested cooperative design has the potential to greatly increase the energy efficiency of the 6G intelligent UAV-assisted wireless powered IoT system when compared to previous benchmark systems.

关键词： 6G wireless powered network energy efficiency IoT intelligent network UAV communication

Derivative Spectroscopy and its Application at Detecting the Weak Emission/Absorption lines

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第3期24卷 205-223页

作者： lihuan Yu Jiangdan li Jinliang Wang Jiajia li Jiao li Qiang Xi Zhanwen han Yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650011China Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

The development of spectroscopic survey telescopes like Large Sky Area multi-Object Fiber Spectroscopic Telescope(LAMOST),Apache Point Observatory Galactic Evolution Experiment and Sloan Digital Sky Survey has opened up unprecedented opportunities for stellar *** types of stars,such as early-type emission-line stars and those with stellar winds,can be distinguished by the profiles of their spectral *** this paper,we introduce a method based on derivative spectroscopy(DS)designed to detect signals within complex backgrounds and provide a preliminary estimation of curve *** method exhibits a unique advantage in identifying weak signals and unusual spectral line profiles when compared to other popular line detection *** validated our approach using synthesis spectra,demonstrating that DS can detect emission signals three times fainter than Gaussian ***,we applied our method to 579,680 co-added spectra from LAMOST Medium-Resolution Spectroscopic Survey,identifying 16,629 spectra with emission peaks around the Hαline from 10,963 *** spectra were classified into three distinct morphological groups,resulting in nine subclasses as follows.(1)Emission peak above the pseudo-continuum line(single peak,double peaks,emission peak situated within an absorption line,P Cygni profile,Inverse P Cygni profile);(2)Emission peak below the pseudo-continuum line(sharp emission peak,double absorption peaks,emission peak shifted to one side of the absorption line);(3)Emission peak between the pseudo-continuum line.

关键词： line identification-line profiles-methods data analysis-techniques spectroscopic-techniques radial velocities

Geographical Variation in the Advertisement Calls of Leptobrachella ventripunctata(Anura:Megophryidae)in Southwestern China

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2024年第3期15卷 140-151页

作者： Chaobo FENG Tuo SHEN Lang mu Jing liU Shize li Yixin DIAO Haijun SU Forestry College of Guizhou University Guiyang 550025GuizhouChina Guizhou Wildlife Protection Association Guiyang 550025GuizhouChina Department of Resources and Environment Moutai InstituteRenhuai 564500GuizhouChina Research Center for Biodiversity and Nature Conservation Guizhou UniversityGuiyang 550025GuizhouChina Guizhou Karst Environmental Ecosystems Observation and Research Station Ministry of EducationGuiyang 550025GuizhouChina

In anurans,advertisement calls(ACs)are an essential form of intraspecific *** study evaluates geographical variation in the ACs of Leptobrachella ventripunctata in the Guizhou Plateau,southwestern China,and explores correlations between call characteristics,body size,and environmental *** are simple calls of ***,and apparent differences were observed in the ACs among different geographical populations of *** Call duration(CD)revealed a significant positive correlation with altitude and a significant negative correlation with temperature and ***,the Dominant frequency(DF)exhibited a significant negative correlation with altitude and the habitat closure degree and a significant positive correlation with *** variations in ACs between different geographical populations of *** may critically impact the adaptive evolution of species,and the calls may also be relevant for environmental selection.

关键词： anuran bioacoustics environmental factors geographical divergence

The Static Stability Region of an Integrated Electricity-Gas System Considering Voltage and Gas Pressure

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第5期36卷 132-145页

作者： Yunfei mu Zhibin liu Xiangwei Guo Hongjie Jia Kai Hou Xiaodan Yu Bofeng Luo Hairun li Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China State Grid Tianjin Electric Power Company Tianjin 300201China China Southern Power Grid Digital Grid Research Institute Co. Ltd.Guangzhou 510700China

In an integrated electricity-gas system(IEGS),load fluctuations affect not only the voltage in the power system but also the gas pressure in the natural gas *** static voltage stability region(SVSR)method is a tool for analyzing the overall static voltage stability in a power ***,in an IEGS,the SVSR boundary may be overly optimistic because the gas pressure may collapse before the voltage ***,the SVSR method cannot be directly applied to an *** this paper,the concept of the SVSR is extended to the IEGS-static stability region(SSR)while considering voltage and gas ***,criteria for static gas pressure stability in a natural gas system are proposed,based on the static voltage stability criteria in a power ***,the IEGS-SSR is defined as a set of active power injections that satisfies multi-energy flow(MEF)equations and static voltage and gas pressure stability constraints in the active power injection space of natural gas-fired generator units(NGUs).To determine the IEGSSSR,a continuation MEF(CMEF)method is employed to trace the boundary point in one specific NGU scheduling direction.A multidimensional hyperplane sampling method is also proposed to sample the NGU scheduling directions *** obtained boundary points are further used to form the IEGSSSR in three-dimensional(3D)space via a Delaunay triangulation hypersurface fitting ***,the numerical results of typical case studies are presented to demonstrate that the proposed method can effectively form the IEGS-SSR,providing a tool for IEGS online monitoring and dispatching.

关键词： Integrated electricity-gas system Static stability region Continuation multi-energy flow multidimensional hyperplane sampling

A Modified CycleGAN for multi-Organ Ultrasound Image Enhancement via Unpaired Pre-Training

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2024年第3期33卷 194-203页

作者： Haonan han Bingyu Yang Weihang Zhang Dongwei li Huiqi li School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China School of Medical Technology Beijing Institute of TechnologyBeijing 100081China

handheld ultrasound devices are known for their portability and affordability,making them widely utilized in underdeveloped areas and community healthcare for rapid diagnosis and early ***,the image quality of handheld ultrasound devices is not always satisfactory due to the limited equipment size,which hinders accurate diagnoses by *** the same time,paired ultrasound images are difficult to obtain from the clinic because imaging process is ***,we propose a modified cycle generative adversarial network(cycleGAN) for ultrasound image enhancement from multiple organs via unpaired *** introduce an ultrasound image pre-training method that does not require paired images,alleviating the requirement for large-scale paired *** also propose an enhanced block with different structures in the pre-training and fine-tuning phases,which can help achieve the goals of different training *** improve the robustness of the model,we add Gaussian noise to the training images as data *** approach is effective in obtaining the best quantitative evaluation results using a small number of parameters and less training costs to improve the quality of handheld ultrasound devices.

关键词： ultrasound image enhancement handheld devices unpaired images pre-train and finetune cycleGAN

Nonlinear Filtering With Sample-Based Approximation Under Constrained Communication:Progress, Insights and Trends

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1539-1556页

作者： Weihao Song Zidong Wang Zhongkui li Jianan Wang Qing-Long han IEEE the State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of Engineering Peking University the Department of Computer Science Brunel University London the School of Aerospace Engineering Beijing Institute of Technology the School of Science Computing and Engineering Technologies Swinburne University of Technology

The nonlinear filtering problem has enduringly been an active research topic in both academia and industry due to its ever-growing theoretical importance and practical *** main objective of nonlinear filtering is to infer the states of a nonlinear dynamical system of interest based on the available noisy measurements. In recent years, the advance of network communication technology has not only popularized the networked systems with apparent advantages in terms of installation,cost and maintenance, but also brought about a series of challenges to the design of nonlinear filtering algorithms, among which the communication constraint has been recognized as a dominating concern. In this context, a great number of investigations have been launched towards the networked nonlinear filtering problem with communication constraints, and many samplebased nonlinear filters have been developed to deal with the highly nonlinear and/or non-Gaussian scenarios. The aim of this paper is to provide a timely survey about the recent advances on the sample-based networked nonlinear filtering problem from the perspective of communication constraints. More specifically, we first review three important families of sample-based filtering methods known as the unscented Kalman filter, particle filter,and maximum correntropy filter. Then, the latest developments are surveyed with stress on the topics regarding incomplete/imperfect information, limited resources and cyber ***, several challenges and open problems are highlighted to shed some lights on the possible trends of future research in this realm.

关键词： Communication constraints maximum correntropy filter networked nonlinear filtering particle filter sample-based approximation unscented Kalman filter