引力波的直接观测已开启引力波天文学的新篇章,爱因斯坦的百年预言终获证实。空间引力波探测器使得探测0.1 m Hz^1 Hz频段丰富的引力波源成为可能,与地面引力波探测器互为补充,才可实现更加宽广波段的引力波探测,揭开宇宙早期的更多秘...引力波的直接观测已开启引力波天文学的新篇章,爱因斯坦的百年预言终获证实。空间引力波探测器使得探测0.1 m Hz^1 Hz频段丰富的引力波源成为可能,与地面引力波探测器互为补充,才可实现更加宽广波段的引力波探测,揭开宇宙早期的更多秘密。空间激光干涉引力波探测采用外差干涉测量技术,测量间距百万公里的两自由悬浮测试质量间10 pm量级的变化量。望远镜是激光干涉测量系统的重要组成部分,1 pm的光程稳定性及苛刻的杂散光要求,不同于传统的几何成像望远镜。本文根据空间太极计划任务需求,对望远镜的功能及技术要求进行了分析,并完成了原理样机的初步方案设计,针对百万公里远场波前分布,分析了望远镜系统的敏感性,同时完成了在轨光机热集成仿真,为后面原理样机的研制奠定了技术基础。展开更多
以《剑桥科学文摘》(CSA)中的LISA(Library and Information Science Abstracts,《图书馆学和情报学文摘》)数据库为文献源,运用文献计量学方法并结合文献内容,从文献量、语种、著者、期刊和主题等方面对图书情报学2000-2004年图像检索...以《剑桥科学文摘》(CSA)中的LISA(Library and Information Science Abstracts,《图书馆学和情报学文摘》)数据库为文献源,运用文献计量学方法并结合文献内容,从文献量、语种、著者、期刊和主题等方面对图书情报学2000-2004年图像检索领域研究论文进行分析,并指出存在的不足。展开更多
Laser Interferometer Space Antenna(LISA)is a project to detect and measure gravitational waves.The project has three spacecraft ying in a formation of near equilateral triangle in a heliocentric orbit trailing Earth.M...Laser Interferometer Space Antenna(LISA)is a project to detect and measure gravitational waves.The project has three spacecraft ying in a formation of near equilateral triangle in a heliocentric orbit trailing Earth.Many sources of perturbations cause the con guration to deviate from the nominal.This paper studies the formation design problem for a LISA-like mission by considering ephemeris-based dynamics.This type of mission is well-known for addressing several strict mission requirements under the realistic dynamics.The problem is formulated as optimizing multiple mission performance indices.It is observed that some indices are correlated with each other,whereas some indices have di erent sensitivities with respect to the semi-major axis.Therefore,the problem is transformed into a two-step cascade single-objective optimization,in which the optimal solution of the rst optimization problem is fed to the second optimization as initial value.In addition,the major perturbing celestial bodies are picked up to make a simpli ed but accurate enough dynamics to speed up the optimization.Numerical examples verify the analysis and show the e ectiveness of the optimization procedure.The in uences of mission lifetime and spatial scales on the optimal solutions are also presented.展开更多
文摘以《剑桥科学文摘》(CSA)中的LISA(Library and Information Science Abstracts,《图书馆学和情报学文摘》)数据库为文献源,运用文献计量学方法并结合文献内容,从文献量、语种、著者、期刊和主题等方面对图书情报学2000-2004年图像检索领域研究论文进行分析,并指出存在的不足。
基金The work was supported by the Hundred Talents Program of the Chinese Academy of Sciences and Strategic Priority Program A(Grant No.XDA15014902).
文摘Laser Interferometer Space Antenna(LISA)is a project to detect and measure gravitational waves.The project has three spacecraft ying in a formation of near equilateral triangle in a heliocentric orbit trailing Earth.Many sources of perturbations cause the con guration to deviate from the nominal.This paper studies the formation design problem for a LISA-like mission by considering ephemeris-based dynamics.This type of mission is well-known for addressing several strict mission requirements under the realistic dynamics.The problem is formulated as optimizing multiple mission performance indices.It is observed that some indices are correlated with each other,whereas some indices have di erent sensitivities with respect to the semi-major axis.Therefore,the problem is transformed into a two-step cascade single-objective optimization,in which the optimal solution of the rst optimization problem is fed to the second optimization as initial value.In addition,the major perturbing celestial bodies are picked up to make a simpli ed but accurate enough dynamics to speed up the optimization.Numerical examples verify the analysis and show the e ectiveness of the optimization procedure.The in uences of mission lifetime and spatial scales on the optimal solutions are also presented.
