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Machine Learning for Improving Stellar Image-based Alignment in Wide-field Telescopes

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Research in Astronomy and Astrophysics 2022年第1期22卷 85-95页

作者： Zhixu Wu Yiming Zhang rongxin tang Zhengyang Li Xiangyan Yuan Yong Xia Hua Bai Bo Li Zhou Chen Xiangqun Cui Xiaohua Deng Institute of Space Science and Technology Nanchang UniversityNanchang 330031China Nanjing Institute of Astronomical Optics and Technology Chinese Academy of SciencesNanjing 210042China

Stellar images will deteriorate dramatically when the sensitive elements of wide-field survey telescopes are misaligned during an observation, and active alignment is the key technology to maintain the high resolution of wide-field sky survey telescopes. Instead of traditional active alignment based on field-dependent wave front errors, this work proposes a machine learning alignment metrology based on stellar images of the scientific camera,which is more convenient and higher speed. We first theoretically confirm that the pattern of the point-spread function over the field is closely related to the misalignment status, and then the relationships are learned by twostep neural networks. After two-step active alignment, the position errors of misalignment parameters are less than5 μm for decenter and less than 5″ for tip-tilt in more than 90% of the cases. The precise alignment results indicate that this metrology provides a low-cost and high-speed solution to maintain the image quality of wide-field sky survey telescopes during observation, thus implying important significance and broad application prospects.

关键词： telescopes techniques:high angular resolution techniques:miscellneous

Structures of magnetic null points in reconnection diffusion region:Cluster observations

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Chinese Science Bulletin 2008年第12期53卷 1880-1886页

作者： HU YunHui DENG XiaoHua ZHOU Meng tang rongxin ZHAO Hui FU Song SU ZhiWen WANG JingFang YUAN ZhiGang R. NAKAMURA W. BAUMJOHANN H. REME C. M. CARR School of Electronic Information State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100012 China Space Research Institute Austrian Academy of Sciences 6 A-8042 Graz Austria Centre d'Etudes Spatiale des Rayonnements BP 4346 31028 Toulouse Cedex 4 France The Blackett Laboratory Imperial College London SW7 2BZ UK

Magnetic reconnection is a very important and fundamental plasma process in transferring energy from magnetic field into plasma. Previous theory, numerical simulations and observations mostly concen-trate on 2-dimensional (2D) model; however, magnetic reconnection is a 3-dimensional (3D) nonlinear process in nature. The properties of reconnection in 3D and its associated singular structure have not been resolved completely. Here we investigate the structures and characteristics of null points inside the reconnection diffusion region by introducing the discretized Poincaré index through Gauss integral and using magnetic field data with high resolution from the four satellites of Cluster mission. We esti-mate the velocity and trajectory of null points by calculating its position in different times, and compare and discuss the observations with different reconnection models with null points based on character-istics of electric current around null points.

关键词：三维磁零点扩散现象等离子体能量转换

An improved iterative algorithm utilized in data processing for incoherent scatter radar

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An improved iterative algorithm utilized in data processing ...

2020年中国地球科学联合学术年会

作者： Jiawei Xiong Kai Yuan rongxin tang Ming Yao Xiaohua Deng Nanchang University

The nonlinear inversion algorithms used to play important roles in data processing for incoherent scatter radars. Those nonlinear algorithms invole in ionospheric parameter extraction. In such process, the initial values for ionospheric parameters are given, and then the initial power spectrum could be obtained. The error between the initial power spectrum and the measured power spectrum is minimized with iteration process.

关键词： An improved iterative algorithm utilized in data processing for incoherent scatter radar

Theoretical study on the impacts of space plasma on the radiation performance of spaceborne antenna

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Theoretical study on the impacts of space plasma on the radi...

2020年中国地球科学联合学术年会

作者： Zhao Ziyang Yuan Kai tang rongxin Yao Ming Deng Xiaohua Nanchang University

The radiation performance of an antenna is impacted by the electromagnetic characteristics of media surrounding the antenna. Most of antennas used to working in neutral atmosphere. In such a case, the surrounding media is the neutral air. In other words, the electromagnetic characteristics of the surrounding media could be treated as vacuum. However, the surrounding media for spaceborne antenna is space plasma.

关键词： Theoretical study on the impacts of space plasma on the radiation performance of spaceborne antenna

Modulation Of Whistler-Mode Waves By Ultra-Low Frequency Wave In a Magnetic Hole: MMS Observation

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Modulation Of Whistler-Mode Waves By Ultra-Low Frequency Wav...

2020年中国地球科学联合学术年会

作者： He Zhang rongxin tang Zhihong Zhong X.H.Deng M Zhou Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education School of Resources Environmental & C Institute of Space Science and Technology Nanchang University

Magnetic hole is a common structure in the interplanetary magnetic fields. It is ubiquitous in various space plasmas such as the solar wind, the earth's magnetosheath, and the magnetosphere. Due to the different formation mechanisms, magnetic hole can vary from the magneto-hydrodynamic(MHD) scale to the kinetic scale. The wave-particle interaction inside or outside the magnetic hole is very important to understand the basic dynamical process for this structure. In this study, by using high resolution MMS data,

关键词： MMS Observation Modulation Of Whistler-Mode Waves By Ultra-Low Frequency Wave In a Magnetic Hole

Efficient silencing of the multicopy DUX4 gene by ABE-mediated start codon mutation in human embryos

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Journal of Genetics and Genomics 2022年第10期49卷 982-985页

作者： Yubing Liu Xinmei Lu Min Ye Ling Wang rongxin tang Zhiyong Yang Bongkoch Turathum Chenchen Liu Yujing Xue Menghua Wu Yannan Yang Ermeng Gao Di Zhang Feng Yang Keh-Kooi Kee Xingxu Huang Guanglei Li Ri-Cheng Chian Center for Reproductive Medicine Tenth People's Hospital of Tongji University301 Middle Yanchang RoadShanghai 200072China Center for Reproductive Medicine Zhongshan HospitalFudan University180 Fenglin RoadShanghai 200032China Center for Stem Cell Biology and Regenerative Medicine Department of Basic Medical SciencesSchool of MedicineTsinghua UniversityBeijing 100084China Department of Basic Medical Science Faculty of Medicine Vajira HospitalNavamindradhiraj UniversityBangkok 10300Thailand School of Life Science and Technology Shanghai Tech University100 Haike RoadPudong New AreaShanghai 201210China

The Dux gene plays an important role in mouse embryo development(De Iaco et al.,2017;Hendrickson et al.,2017;Whiddon et al.,2017).It participates in the maternal-to-zygotic transition(MTZ),which mainly includes maternal transcript degradation and zygotic genome activation(ZGA)and is the key process for embryonic *** 11-100 copies of the DUX4 gene form a tandem cluster in the human genome(Snider et al.,2009,2010).

关键词： development maternal

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关于纯电动汽车问题分析及优化研究

汽车电器 2023年第11期 21-22,26页

作者：唐荣鑫南宁学院广西南宁541699

在电动化和人工智能化的大背景下,传统燃油汽车将会被逐渐淘汰,新能源汽车将成为时代新的潮流,为汽车行业发展注入新的活力,特别是如今全球生态面临着严峻挑战,减少环境污染成为社会发展的必然趋势,新能源汽车的出现能有效缓解环境污染... 详细信息

在电动化和人工智能化的大背景下,传统燃油汽车将会被逐渐淘汰,新能源汽车将成为时代新的潮流,为汽车行业发展注入新的活力,特别是如今全球生态面临着严峻挑战,减少环境污染成为社会发展的必然趋势,新能源汽车的出现能有效缓解环境污染等社会问题。但在新能源汽车发展迅速的同时,也存在着一些不可忽视的问题。文章从纯电动汽车的工作原理和发展趋势入手,通过分析总结出纯电动汽车发展现状中的不足之处,最后针对不足之处提出一些可行性的建议。

关键词：纯电动汽车电池安全传统燃油车

土星能量电子通量统计研究以及土星卫星的影响

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土星能量电子通量统计研究以及土星卫星的影响

中国空间科学学会空间物理学专业委员会第十五届全国日地空间物理学研讨会

作者： rongxin tang Danny Summers Xiaohua Deng Institute of Space Science and Technology Nanchang University Department of Mathematics and Statistics Memorial University of NewfoundlandSt.John'sNewfoundlandCanada School of Space Research Kyung Hee University

Energetic electron fluxes(18 keV-21 MeV)observed by the MIMI/LEMMS instrument on the Cassini mission during 2004 to 2008 are *** consider all 101 orbits and we select portions of the orbits that lie within 0.5 RS of the magnetic equatorial plane,where RS is Saturn’s *** determine the average electron differential flux and integral flux at specified L-shells in the range 4:5

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数字电视广播外辐射源雷达子带处理方法研究

现代电子技术 2018年第3期41卷 57-62页

作者：曾舰洪升唐荣欣严茂松南昌大学信息工程学院江西南昌330031

数字电视广播外辐射源雷达的信号带宽大、基带采样率高,使得该体制雷达面临数据实时传输和处理的困难。针对基于中国移动多媒体广播(CMMB)信号的外辐射源雷达,利用CMMB信号的部分带宽来降低基带采样率,提出一种子带处理方法。其中,重点... 详细信息

数字电视广播外辐射源雷达的信号带宽大、基带采样率高,使得该体制雷达面临数据实时传输和处理的困难。针对基于中国移动多媒体广播(CMMB)信号的外辐射源雷达,利用CMMB信号的部分带宽来降低基带采样率,提出一种子带处理方法。其中,重点研究了重采样率设置、参考信号子带提纯和子带匹配问题,并结合多径杂波抑制和匹配滤波处理分析子带宽度和纯度对目标探测性能的影响。仿真和实测数据处理结果验证了所提方法的有效性,为该体制雷达的实时化奠定了基础。

关键词：数字电视广播外辐射源雷达 CMMB 子带处理多径杂波抑制匹配滤波实时化