A low-temperature-resistant and high-strength stainless-steel jacket is a key component in the superconducting magnet of a fusion reactor.The development of cryogenic structural materials with high strength and toughn...A low-temperature-resistant and high-strength stainless-steel jacket is a key component in the superconducting magnet of a fusion reactor.The development of cryogenic structural materials with high strength and toughness poses a challenge for the future development of high-field superconducting magnets in fusion reactors.The yield strength of the International Thermonuclear Experimental Reactor developed for low-temperature structural materials at 4.2K is below 1100MPa,which fails to meet the demand for structural components with yield strengths exceeding 1500MPa at 4.2K in the future fusion reactors.CHSN01(formerly N50H),which is a low-temperature structural material developed in China,exhibits exceptional strength and toughness,thereby making it highly promising for practical applications.Recently,a 30 t jacket measuring approximately 5000m in total length was produced.Its low-temperature mechanical properties were tested using a sampling method to ensure compliance with application requirements.This paper presents the experimental data of the CHSN01 jacket and tests of the physical properties of the material in the temperature range of 4–300 K.The physical properties were unaffected by magnetic field.Furthermore,this paper discusses the feasibility of employing CHSN01 as a cryogenic structural material capable of withstanding high magnetic fields in next-generation fusion reactors.展开更多
To assess the effectiveness of vaccination in contaminated environments,this study introduces a modeling framework that encompasses two transmission routes,namely direct human-to-human contact and indirect human-to-en...To assess the effectiveness of vaccination in contaminated environments,this study introduces a modeling framework that encompasses two transmission routes,namely direct human-to-human contact and indirect human-to-environment contact,as well as the implementation of new M72/AS01_(E)vaccine.Motivated by this,a coupled age-structured tuberculosis(TB)model is proposed.Its well-posedness requirement is verified using the integrated semigroup theory.Furthermore,this study presents a comprehensive analysis of threshold dynamics associated with the proposed model.Specifically,the global stability of the disease-free and positive steady states is demonstrated by employing Lyapunov functionals.Lastly,the effects of the vaccination with M72/AS01_(E)and contaminated environments on TB control are numerically simulated.Experimental results indicate that high concentrations of Mycobacterium tuberculosis in contaminated environments may somewhat impede TB control efforts,but that large-scale deployment of new vaccine could significantly reduce the prevalence of TB.展开更多
珞珈二号01星的高分辨率Ka频段合成孔径雷达(synthetic aperture radar,SAR)为地表水体的精确监测提取提供了新数据源,但其毫米波雷达在精确刻画水体的同时,也引入了较多的地物信息干扰,对SAR的水体识别提出了更高要求。为应对这一挑战...珞珈二号01星的高分辨率Ka频段合成孔径雷达(synthetic aperture radar,SAR)为地表水体的精确监测提取提供了新数据源,但其毫米波雷达在精确刻画水体的同时,也引入了较多的地物信息干扰,对SAR的水体识别提出了更高要求。为应对这一挑战,提出了一种适用于高分辨率Ka频段SAR影像的KWEnet水体范围提取方法(the improved U-Net model for water extraction based on Ka-band SAR images),该方法在U-Net模型的上采样过程中增加了注意力机制,实现对特征图的加权,强化了水体信息的权重,减少对建筑物阴影等干扰特征的关注。将该方法应用于海河“23·7”流域性特大洪水事件,结果表明:KWEnet的F1分数(F1)、总体分类精度(overall accuracy,OA)以及交并比(intersection over union,IOU)分别达到95.6%、96.2%和91.5%,且在提取连通水体、减少漏提及剔除无关地物干扰等方面表现优异,对于星载Ka SAR的水体识别、洪涝灾害的监测和地表水资源的利用等具有重要意义。展开更多
珞珈二号01星是我国首颗高分辨率Ka频段SAR(synthetic aperture radar)卫星,它开辟了新的成像频段。该卫星围绕Ka频段新体制、雷达天线方位向电扫的技术特点开展视频SAR等多种模式的设计,以此实现新的应用能力。珞珈二号01星通过平台轻...珞珈二号01星是我国首颗高分辨率Ka频段SAR(synthetic aperture radar)卫星,它开辟了新的成像频段。该卫星围绕Ka频段新体制、雷达天线方位向电扫的技术特点开展视频SAR等多种模式的设计,以此实现新的应用能力。珞珈二号01星通过平台轻小型设计保障载荷工作能力,卫星平台载荷采取机电热一体化设计、平台电子设备板卡式高集成设计以及高效的MPPT(maximum power point tracking)供电技术等。同时,结合在轨实际应用情况介绍了卫星的能力水平及技术指标实现情况。展开更多
基金supported in part by the National Natural Science Foundation of China(No.12305196)Anhui Provincial Natural Science Foundation(No.2308085QA23)+1 种基金Open Fund of Magnetic confinement Fusion Laboratory of Anhui Province(No.2023AMF03003)Science Foundation of Institute of Plasma Physics,Chinese Academy of Sciences(No.DSJJ-2024-10).
文摘A low-temperature-resistant and high-strength stainless-steel jacket is a key component in the superconducting magnet of a fusion reactor.The development of cryogenic structural materials with high strength and toughness poses a challenge for the future development of high-field superconducting magnets in fusion reactors.The yield strength of the International Thermonuclear Experimental Reactor developed for low-temperature structural materials at 4.2K is below 1100MPa,which fails to meet the demand for structural components with yield strengths exceeding 1500MPa at 4.2K in the future fusion reactors.CHSN01(formerly N50H),which is a low-temperature structural material developed in China,exhibits exceptional strength and toughness,thereby making it highly promising for practical applications.Recently,a 30 t jacket measuring approximately 5000m in total length was produced.Its low-temperature mechanical properties were tested using a sampling method to ensure compliance with application requirements.This paper presents the experimental data of the CHSN01 jacket and tests of the physical properties of the material in the temperature range of 4–300 K.The physical properties were unaffected by magnetic field.Furthermore,this paper discusses the feasibility of employing CHSN01 as a cryogenic structural material capable of withstanding high magnetic fields in next-generation fusion reactors.
文摘To assess the effectiveness of vaccination in contaminated environments,this study introduces a modeling framework that encompasses two transmission routes,namely direct human-to-human contact and indirect human-to-environment contact,as well as the implementation of new M72/AS01_(E)vaccine.Motivated by this,a coupled age-structured tuberculosis(TB)model is proposed.Its well-posedness requirement is verified using the integrated semigroup theory.Furthermore,this study presents a comprehensive analysis of threshold dynamics associated with the proposed model.Specifically,the global stability of the disease-free and positive steady states is demonstrated by employing Lyapunov functionals.Lastly,the effects of the vaccination with M72/AS01_(E)and contaminated environments on TB control are numerically simulated.Experimental results indicate that high concentrations of Mycobacterium tuberculosis in contaminated environments may somewhat impede TB control efforts,but that large-scale deployment of new vaccine could significantly reduce the prevalence of TB.
文摘珞珈二号01星的高分辨率Ka频段合成孔径雷达(synthetic aperture radar,SAR)为地表水体的精确监测提取提供了新数据源,但其毫米波雷达在精确刻画水体的同时,也引入了较多的地物信息干扰,对SAR的水体识别提出了更高要求。为应对这一挑战,提出了一种适用于高分辨率Ka频段SAR影像的KWEnet水体范围提取方法(the improved U-Net model for water extraction based on Ka-band SAR images),该方法在U-Net模型的上采样过程中增加了注意力机制,实现对特征图的加权,强化了水体信息的权重,减少对建筑物阴影等干扰特征的关注。将该方法应用于海河“23·7”流域性特大洪水事件,结果表明:KWEnet的F1分数(F1)、总体分类精度(overall accuracy,OA)以及交并比(intersection over union,IOU)分别达到95.6%、96.2%和91.5%,且在提取连通水体、减少漏提及剔除无关地物干扰等方面表现优异,对于星载Ka SAR的水体识别、洪涝灾害的监测和地表水资源的利用等具有重要意义。
文摘珞珈二号01星是我国首颗高分辨率Ka频段SAR(synthetic aperture radar)卫星,它开辟了新的成像频段。该卫星围绕Ka频段新体制、雷达天线方位向电扫的技术特点开展视频SAR等多种模式的设计,以此实现新的应用能力。珞珈二号01星通过平台轻小型设计保障载荷工作能力,卫星平台载荷采取机电热一体化设计、平台电子设备板卡式高集成设计以及高效的MPPT(maximum power point tracking)供电技术等。同时,结合在轨实际应用情况介绍了卫星的能力水平及技术指标实现情况。
