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Effects of various solar indices on accuracy of Earth’s thermospheric neutral density models

Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1120-1128页

作者： wang hongbo1,2 & zhao changyin1 1 purple mountain observatory, chinese academy of sciences, nanjing 210008, china 2 Graduate University of chinese academy of sciences, Beijing 100049, china purple mountain observatory Chinese Academy of Sciences Nanjing China Graduate University of chinese academy of sciences Beijing China

Four kinds of solar indices F10.7, E10.7, S10, Mg10 and four thermospheric neutral density models, i.e., CIRA72, DTM94, NRLMSISE00 and JB2006, are discussed. The CHAMP accelerometer data are used to calculate thermospheric total mass density. Based on the comparison of the model densities with CHAMP observations, the effects of various indices on the model accuracy are detected. It is found that under quiet and moderate solar conditions (F10.7160), all of the models’ errors are reduced about 15% by using E10.7 instead of F10.7, while under active solar conditions (F10.7>200) the error’s standard deviation using E10.7 increases quickly and causes the models’ accuracy to fall down. With regard to S10, Mg10, their effects under quiet solar conditions are inconspicuous. If under active solar conditions, they can reduce the model error’s standard deviation by 5%-10%, implying that S10, Mg10 make the model error more stable. The JB2006 model, which was constructed by multi-solar-index (F10.7, S10, Mg10), is compared with DTM94 and NRLMSISE00 based on single-solar-index. It is found that JB2006’s accuracy is better than DTM94’s, and is close to NRLMSISE00 under the quiet solar condition. During the solar burst occurring on October 26, 2003, JB2006 has been in best agreement with CHAMP observations. All in all, the new indices may improve thermospheric density models’ accuracy under some special conditions. Concretely, E10.7 may reduce the average error of models and S10, Mg10 may prevent the error’s divergence.

关键词： solar radiation index CHAMP accelerometer data neutrals density model

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Primary scientific results of Chang'E-1 lunar mission

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Science china Earth sciences 2010年第11期53卷 1565-1581页

作者： OUYANG ZiYuan1,2, LI ChunLai1, ZOU YongLiao1, ZHANG hongbo1, Lü Chang1, LIU JianZhong1, LIU JianJun1, ZUO Wei1, SU Yan1, WEN WeiBin1, BIAN Wei1, zhao BaoChang3, wang JianYu4, YANG JianFeng3, CHANG Jin5, wang HuanYu6, ZHANG XiaoHui7, wang ShiJin7, wang Min1, REN Xin1, MU LingLi1, KONG DeQing1, wang XiaoQian1, wang Fang1, GENG Liang1, ZHANG ZhouBin1, ZHENG Lei1, ZHU XinYing1, ZHENG YongChun1, LI JunDuo1, ZOU XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, chinese academy of sciences, Beijing 100012, china 2 Institute of Geochemistry, chinese academy of sciences, Guiyang 550002, china 3 Xi’an Institute of Optics and Precision Mechanics, chinese academy of sciences, Xi’an 710119, china 4 Shanghai Institute of Technical Physics, chinese academy of sciences, Shanghai 200083, china 5 purple mountain observatory, chinese academy of sciences, nanjing 210008, china 6 Institute of High Energy Physics, chinese academy of sciences, Beijing 100049, china 7 Center for Space Science and Applied Research, chinese academy of sciences, Beijing 100190, china National Astronomical Observatories Chinese Academy of Sciences Beijing China Institute of Geochemistry Chinese Academy of Sciences Guiyang China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an China Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai China purple mountain observatory Chinese Academy of Sciences Nanjing China Institute of High Energy Physics Chinese Academy of Sciences Beijing China Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

The strategic plan for the development of the unmanned chinese Lunar Exploration Program is characterized by three distinct stages: "orbiting around", "landing on" and "returning from" the Moon. The first chinese lunar probe, Chang'E-1, which was successfully launched on October 24th, 2007 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1st, 2009, at 52.36°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the "orbiting around" stage. The Chang'E-1 mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.37 TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the "global lunar image from the first chinese lunar explora- tion mission". All scientific goals of Chang'E-1 have been achieved. It provides much useful materials for further advances of lunar sciences and planetary chemistry. Meanwhile, these results will serve as a firm basis for future chinese lunar missions.

关键词： lunar orbiter Chang’E-1 scientific data results

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Tillage Pedogenesis of purple Soils in Southwestern china

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Journal of mountain Science 2009年第2期6卷 205-210页

作者： HE Xiubin BAO Yuhai NAN Hongwei XIONG Donghong wang Li LIU Yanfeng zhao Jingbo Institute of mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Graduate School of the chinese academy of sciences Beijing 100049 China Shaanxi Normal University Xi'an 710062 China

Land cultivation and tillage process, and their consequent impacts on soil erosion, have been criticized as the main cause of degradation of land or soil quality. However, purple soils, classified as Regosols in FAO Taxonomy or Entisols in USDA Taxonomy, are formed from purple rocks of the Trias- Cretaceous system, have been developed or at least accelerated the development due to continual tillage operation, especially digging and ridging. The present study took micromorphological investigation on the sedimentary rocks and the soils under different operations of tillage. Results show that the purple rock of Feixiangguan Formation of the Trias system （Tlf） is the easiest to physical weathering and the most fertile soil material enriched in nutrients, and it has been, therefore, mostly cultivated and intensively tilled around the year. It has the fastest soil formation rate. Soil formation rate in the cropland with conventional tillage is higher than that in the forestiand and the grassland. It implies that the artificial brokenness and tillage disturbance play a great role in physical weathering and initiating soil formation processes.

关键词： Tillage impact pedogenesis purple soil micromorphology southwestern china

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Progress in Space Debris Research

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空间科学学报 2010年第5期30卷 516-518页

作者： zhao changyin Zhang Wenxiang Han Zengyao wang hongbo Key Laboratory of Space Object and Debris Observation Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 Shanghai academy of Spacefight Technology china academy of Space Technology

During recent years,A de-orbit disposal of SinoSat 2 satellite and the depletion of the residual propellant after SC/LV separation for all LM-4 series launch vehicles were carried *** Whipple Shields based on hypervelocity impact particles were *** observation and collision avoidance were *** main progress in space debris research will be introduced from three aspects:mitigation,spacecraft protection,observation and collision avoidance.

关键词：空间碎片鑫诺2号卫星超高速撞击运载火箭避免碰撞供应链推进剂航天器

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Surface shape detection methods for large radio telescopes

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Astronomical Techniques and Instruments 2024年第5期1卷 275-283页

作者： Zhengxiong Sun Jinqing wang Linfeng Yu Yongchen Jiang Zheng Lou Yongbin Jiang Rongbin zhao Qian Ye Qinghui Liu Guangli wang Shanghai Astronomical observatory Chinese Academy of SciencesShanghai 200030China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210023China Shanghai Key Laboratory of Space Navigation and Positioning Techniques Shanghai 200030China University of chinese academy of sciences Beijing 100049China purple mountain observatory Chinese Academy of SciencesNanjing 210023China

The surface accuracy of a radio telescope is directly related to its operational efficiency and detection *** is crucial under high-frequency observation conditions,where surface shape errors need to be controlled to within 1/16 of the working *** addition,the primary reflector of large radio telescopes is subject to dynamic deformation,caused by factors such as gravity and thermal *** paper presents a method for detecting the surface shape of radio telescopes using radio interferometry techniques combined with active reflector adjustment *** enables accurate assessment and correction of surface errors,ensuring the electrical performance of the radio *** study investigates the practical applications of high-precision measurement techniques,such as microwave holography,out-of-focus holography,and wavefront distortion methods at the Tianma 65 m radio telescope(TMRT).Furthermore,the study presents the construction method of gravity models at different elevation angles and demonstrates the efficacy of the active reflector *** results of the measurements indicate that the application of these methods to the TMRT has led to a notable enhancement of the accuracy of the primary reflector and a substantial improvement in efficiency in the *** a process of iterative measurements and adjustments,the surface shape error is ultimately reduced to 0.28 mm root mean square(RMS).

关键词： Radio telescope Holographic measurements Surface shape measurements Antenna efficiency

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基于GPS接收机的程控目标跟踪方法的气球飞行试验

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天文学报 1999年第3期40卷 307-311页

作者：杭恒荣李小青刘善昭王楠森宫一忠张仁健中国科学院紫金山天文台南京210008

简要介绍了基于ＧＰＳ接收机的程控目标跟踪方法原理和１９９８年５月的一次气球飞行试验结果．成功的飞行试验证明该方法对于用准直器限制视场的Ｘ射线和＄射线气球天文观测非常适用，可提高观测灵敏度和简化数据处理过程。

关键词：气球观测目标跟踪程序控制 GPS 接收机

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A compact multi-pixel superconducting nanowire single-photon detector array supporting gigabit space-to-ground communications

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Light(Science & Applications) 2024年第2期13卷 254-266页

作者： Hao Hao Qing-Yuan zhao Yang-Hui Huang Jie Deng Fan Yang Sai-Ying Ru Zhen Liu Chao Wan Hao Liu Zhi-Jian Li Hua-Bing wang Xue-Cou Tu La-Bao Zhang Xiao-Qing Jia Xing-Long Wu Jian Chen Lin Kang Pei-Heng Wu Research Institute of Superconductor Electronics(RISE) School of Electronic Science and EngineeringNanjing UniversityNanjingJiangsu 210023China purple mountain Laboratories NanjingJiangsu 211111China Hefei National Laboratory HefeiAnhui 230088China National Laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityNanjing 210023China

Classical and quantum space-to-ground communications necessitate highly sensitive receivers capable of extracting information from modulated photons to extend the communication distance from near-earth orbits to deep space *** achieve gigabit data rates while mitigating strong background noise photons and beam drift in a highly attenuated free-space channel,a comprehensive design of a multi-functional detector is *** this study,we present an innovative compact multi-pixel superconducting nanowire single-photon detector array that integrates near-unity detection efficiency(91.6%),high photon counting rate(1.61 Gcps),large dynamic range for resolving different photon numbers(1-24),and four-quadrant position sensing function all within one ***,we have constructed a communication testbed to validate the advantages offered by such an *** 8-PPM(pulse position modulation)format communication experiments,we have achieved an impressive maximum data rate of 1.5 Gbps,demonstrating sensitivities surpassing previous benchmarks at respective *** incorporating photon number information into error correction codes,the receiver can tolerate maximum background noise levels equivalent to 0.8 photons/slot at a data rate of 120 Mbps—showcasing a great potential for daylight operation ***,preliminary beam tracking tests were conducted through open-loop scanning techniques,which revealed clear quantitative dependence indicating sensitivity variations based on beam *** on the device characterizations and communication results,we anticipate that this device architecture,along with its corresponding signal processing and coding techniques,will be applicable in future space-to-ground communication tasks.

关键词： photon supporting correction

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The unified ideal model of mean motion resonance of artificial satellites due to geopotential perturbations

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Science china(Physics,Mechanics & Astronomy) 2013年第4期56卷 840-847页

作者： ZHANG MingJiang zhao changyin XIONG YongQing SUN RongYu ZHU TingLei purple mountain observatory Chinese Academy of Sciences Key Laboratory of Space Object and Debris Observation Purple Mountain Observatory Chinese Academy of Sciences University of chinese academy of sciences

From Kaula's Earth gravitational potential written in classical orbital elements, the unified ideal model of mean motion resonance of artificial satellites due to geopotential perturbations is developed in this paper first, through a suitable sequence of canonical transformations constructed by implicit functions. This unified ideal orbital resonance model is valid for all the commensurabilities between the rotational angular velocity of the Earth and the angular velocities of mean orbital motion of artificial satellites with arbitrary inclination and small eccentricity, and can be also transformed into Garfinkel's general expression of ideal resonance problem. Then 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity is analyzed under the effect of harmonics of J2 and J 22 of the geopotential, based on the unified ideal model of mean motion resonance. The analytical expressions of the libration period and libration half width of the 1/1 resonance of the 24-hour satellite with arbitrary inclination and small eccentricity are presented.

关键词： artificial satellite mean motion orbital resonance unified ideal model

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川中紫色土旱坡地磷素的输出特征研究

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水土保持学报 2004年第6期18卷 97-99页

作者：李庆召王定勇朱波刘军坛郑州航空工业管理学院环境工程系郑州450015 西南农业大学资源环境学院重庆400716 中国科学院成都山地灾害与环境研究所成都610041

在中国科学院盐亭农业生态站进行了为期1年(2002 4～2003 4)的定期监测研究,探讨了磷素的农业非点源输出规律。研究表明紫色土旱坡地磷素输出以颗粒吸附态为主,全磷输出量不高,但水溶性磷素和磷酸盐的输出浓度对环境的影响应值得重视。... 详细信息

在中国科学院盐亭农业生态站进行了为期1年(2002 4～2003 4)的定期监测研究,探讨了磷素的农业非点源输出规律。研究表明紫色土旱坡地磷素输出以颗粒吸附态为主,全磷输出量不高,但水溶性磷素和磷酸盐的输出浓度对环境的影响应值得重视。全磷的输出随不同的耕作方式不同而不同,短期降雨:顺坡>平作>垄作;垄作种植,在长期降雨条件下,水溶性磷的径流输出将会增大,从而使全磷的输出量相应增加,即长期阴雨天气下,全磷的输出量:顺坡种植、垄作>平作。通过分析还发现磷素地下渗漏与降雨量之间也存在类似的关系,即磷素下渗浓度存在极值,它与降雨量之间不是单调递增关系,而是开口向下的抛物线,其相关系数为R2=0 9232。

关键词：四川紫色土旱坡地磷素输出特征

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Einstein Probe discovery of EP240408a:A peculiar X-ray transient with an intermediate timescale

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Science china(Physics,Mechanics & Astronomy) 2024年

作者： Wenda Zhang Weimin Yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang Yonghe Zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P. U. Fynbo Lluis Galbany Saurabh W. Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng wang Song wang Tinggui wang Zhongxiang wang Qingwen Wu Xuefeng Wu Dong Xu Yanjun Xu Suijian Xue Yongquan Xue Zijian Zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao wang Juan wang Lei wang Wenxin wang Yilong wang Yusa wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang Donghua zhao Haisheng zhao Xiaofan zhao Zijian zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation academy for Microsatellites chinese academy of sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University National Astronomical Observatories Department of Physics Anhui Normal University Shanghai Institute of Technical Physics chinese academy of sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas chinese academy of sciences South African Astronomical observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Universite' Paris Cite' CNRS Astroparticule et Cosmologie Universite' Paris Cite' CEA Paris-Saclay School of Astronomy and Space sciences IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research University of chinese academy of sciences The University of Tokyo ESA/ESTEC Noordwijk 2201 AZ The Netherlands Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics Key Laboratory of Particle Astrophysics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology Hefei School of Astronomy and Space sciences University of Science and Technology of china Institute of High Energy Physics Institute of Deep Space sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical observatory chinese academy of Science

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 keV,300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for4d,followed by a steep decay till becoming undetectable10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

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