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Highlight Advances in Planetary Physics in the Solar System: In Situ Detection Over the Past 20 Years

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space(Science & Technology) 2023年第1期3卷 24-53页

作者： Yixin Sun Jiutong Zhao Chuanpeng Hou Weixin Jiao Center of Planetary and space Sciences Peking UniversityBeijingChina

Planetary science is the science of studying planets,moons,and planetary *** scale of the research objects ranges from small meteoroids to large gas giant planets,and the research purpose is to determine their composition,dynamics,formation,evolution,mutual relationship,and *** the development of human space technology,planetary exploration has become one of the most important space exploration activities of *** to statistics from the spacecraft Encyclopedia website,as of December 2021,a total of 252 planetary probes have been launched around the *** missions reveal the deep space to *** this paper,we review some advances in planetary science made by these missions in the past *** topics involve interior structures,geological features,atmospheres,magnetospheres,and so on,not every aspect but as much as *** there are still many extraordinary scientific results that have not been included,we believe that this review can already help people learn about the scientific results of planetary exploration and hopefully inspire the next generation of planetary missions.

关键词： planetary Solar planet

Tree wavelet approximations with applications

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Science china Mathematics 2005年第5期48卷 680-702页

作者： XU Yuesheng & ZOU Qingsong Department of Mathematics, Syracuse University, Syracuse, NY 13244, USA Institute of Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, china Department of Scientific Computing and Computer Science, Zhongshan University, Guangzhou 510275, china Department of Mathematics Syracuse University Syracuse USA Institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Department of Scientific Computing and Computer Science Zhongshan University Guangzhou China

We construct a tree wavelet approximation by using a constructive greedy scheme (CGS). We define a function class which contains the functions whose piecewise polynomial approximations generated by the CGS have a prescribed global convergence rate and establish embedding properties of this class. We provide sufficient conditions on a tree index set and on bi-orthogonal wavelet bases which ensure optimal order of convergence for the wavelet approximations encoded on the tree index set using the bi-orthogonal wavelet bases. We then show that if we use the tree index set associated with the partition generated by the CGS to encode a wavelet approximation, it gives optimal order of convergence.

关键词： greedy algorithms tree wavelet approximations Besov spaces.

A method for static aeroelastic analysis based on the high-order panel method and modal method

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Science china(Technological Sciences) 2011年第3期54卷 741-748页

作者： YANG Chao ZHANG BoCheng WAN ZhiQiang WANG YaoKun School of Aeronautic Science and Engineering Beijing University of Aeronautics & Astronautics Beijing 100191 China

A method for static aeroelastic analysis based on the high-order panel method and modal method is presented. The static aeroelastic characteristics of flexible wings are investigated using this method. Three-dimensional aerodynamic models of flexible wings are constructed based on the geometry of wing configuration, and the modal method is adopted to achieve the fluid-structure coupling. The static aeroelastic characteristics of the AGARD445.6 wing and a low-aspect-ratio wing are investigated in this study. The influences of elastic structural deformation on aerodynamic forces are studied with an emphasis analyzing the aerodynamic coefficients, wing root loads, structural deformation and pressure distribution of different sections, and results are compared with the results from wind-tunnel tests and the elastic results based on experimental aerodynamic forces. It is concluded that aerodynamic forces can be accurately calculated with the high-order panel method. The method presented in this study is feasible, credible and efficient. Comprehensive static aeroelastic characteristics can be provided by the method for early phases of aircraft design.

关键词： aeroelasticity flight loads high-order panel method modal method experimental aerodynamic forces

Long-term Integration Ability of the Submillimeter Wave Astronomy Satellite(SWAS)Spectral Line Receivers

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Research in Astronomy and Astrophysics 2024年第6期24卷 315-322页

作者： Bing-Ru Wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Rudolf Schieder Gary J.Melnick national Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China KOSMA I.Physik.InstitutUniversität zu KölnZülpicher Str.7750937 KölnGermany Center for Astrophysics|Harvard&Smithsonian 60 Garden StreetMS 66CambridgeMA 02138USA

The Submillimeter Wave Astronomy Satellite(SWAS)was the first space telescope capable of high spectral resolution observations of terahertz spectral *** have investigated the integration ability of its two receivers and spectrometer during five and a half years of on-orbit *** CI,O_(2),H_(2)O,and^(13)CO spectra taken toward all observed Galactic sources were *** present results are based on spectra with a total integration time of up to 2.72×10~4hr(■10~8s).The noise in the spectra is generally consistent with that expected from the radiometer equation,without any sign of approaching a noise *** noise performance reflects the extremely stable performance of the passively cooled front end as well as other relevant components in the SWAS instrument throughout its mission lifetime.

关键词： telescopes space vehicles:instruments instrumentation:miscellaneous ISM:lines and bands

Obtaining space-based SDO/AIA solar UV and EUV images from ground-based Hαobservations by deep learning

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Research in Astronomy and Astrophysics 2021年第6期21卷 233-240页

作者： Tie Liu Ying-Na Su Li-Ming Xu Hai-Sheng Ji Key Laboratory of Dark Matter and space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and space Science University of Science and Technology of ChinaHefei 230026China Jiangsu Urban and Rural Construction College Changzhou 213147China

In this work,we explore the mappings from solar images taken in Hα(6563 A)by the Global Oscillation Network Group(GONG)on the ground to those observed in eight different wavelengths(94,131,171,193,211,304,335 and 1600 A)by SDO/AIA in *** mappings are built by training the conditional Generative Adversarial Networks(cGANs)on datasets with 500 paired images,which are[Hα,AIA94],[Hα,AIA131],[Hα,AIA171],[Hα,AIA193],[Hα,AIA211],[Hα,AIA304],[Hα,AIA335]and[Hα,AIA1600].We evaluate the eight trained cGANs models on validation and test datasets with 154-pair images and 327-pair images,*** model generated fake AIA images match the corresponding observed AIA images well on large-scale structures such as large active regions and *** the small-scale flare loops and filament threads are difficult to *** quantitative comparisons are carried out on the validation and test datasets to score the *** find that the model-generated images in 304 and 1600 A match the corresponding observed images *** exploration suggests that the cGANs are promising methods for mappings between ground-based Ha and space-based EUV/UV images,while some improvements are necessary.

关键词： methods:analytical techniques:image processing Sun:corona Sun:UV radiation

Static aeroelastic analysis of a high-aspect-ratio wing based on wind-tunnel experimental aerodynamic forces

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Science china(Technological Sciences) 2011年第10期54卷 2716-2722页

作者： WAN ZhiQiang ZHANG BoCheng YANG Chao XU Yan School of Aeronautic Science and Engineering Beijing University of Aeronautics & Astronautics Beijing 100191 China Research and Development Center Chengdu Aircraft and Industrial Group Crop. Ltd. Chengdu 610092 China

The aeroelastic responses of a high-aspect-ratio wing are investigated based on nonlinear experimental aerodynamic forces. The influences of nonlinear experimental aerodynamic forces and dynamic pressures on the wing loads are studied in the longitudinal and lateral maneuver states. The flight loads of the wing fixed at the root are calculated at different angles of attack. The aileron efficiency with respect to the dynamic pressures and aileron deflections are also studied. The results indicate that the flight loads of the wings vary nonlinearly with the angle of attack and dynamic pressure. Due to the high-lift aerofoil, elastic components are a large portion of the wing loads, especially for small angles of attack and high dynamic pressure condi-tions. The aileron efficiency is significantly affected by aileron deflections, dynamic pressures and angles of attack when the nonlinear experimental aerodynamic forces are used for calculation. In states with high dynamic pressures and large aileron deflections, aileron reversal can occur. The aileron deflection and angle of attack have a nonlinear effect on the aileron efficiency. An efficient method for analyzing the flight loads and structural design of high-aspect-ratio wings is derived in this study, and the analysis can provide insight into the distribution of flight loads for high-aspect-ratio wings.

关键词： high-aspect-ratio wing aeroelasticity flight loads aileron efficiency aileron reversal experimental aerodynamic forces

Achievements of space Scientific Experiments Aboard SJ-8 Satellite

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空间科学学报 2008年第5期28卷 390-394页

作者： XIE Jingchang WAN Shixin ZHANG Pu LIN Hai LIU Fang HU Wenrui Institute of Mechanics Chinese Academy of Sciences Beijing J00190

As scientific experiment payloads,microgravity experiments of fluid physics,life science,combustion science,physics and accelerator measurement were conducted on board the Chinese recoverable satellite SJ-8 during 18-day orbital *** experimental payloads and an experiment support system constituted the microgravity experiment system of the flight *** article has presented the briefs of the scientific achievements of these space experiments,the composition and performance of the Microgravity Experimental System(MES) and the general picture of the overall flight mission,respectively.

关键词：空间科学实践8号卫星人造卫星地心引力

The Tianwen-1 Guidance, Navigation, and Control for Mars Entry, Descent, and Landing

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space(Science & Technology) 2021年第1期2021卷 84-96页

作者： Xiangyu Huang Maodeng Li Xiaolei Wang Jinchang Hu Yu Zhao Minwen Guo Chao Xu Wangwang Liu Yunpeng Wang Ce Hao Lijia Xu Science and Technology on space Intelligent Control Laboratory Beijing Institute of Control EngineeringBeijing 100091China Beijing Institute of Control Engineering Beijing 100091China

Tianwen-1,the first mission of china’s planetary exploration program,accomplished its goals of orbiting,landing,and roving on the *** entry,descent,and landing(EDL)phase directly determines the success of the entire mission,of which the guidance,navigation,and control(GNC)system is *** paper outlines the Tianwen-1 EDL GNC system design by introducing the GNC requirements followed by presenting the GNC system architecture and algorithms to meet such *** actual flight results for the whole EDL phase are also provided in this paper.

关键词： system GNC landing

The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite

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Science china(Physics,Mechanics & Astronomy) 2020年第4期63卷 20-34页

作者： CongZhan Liu YiFei Zhang XuFang Li XueFeng Lu Zhi Chang ZhengWei Li AiMei Zhang YongJie Jin HuiMing Yu Zhao Zhang MinXue Fu YiBao Chen JianFeng Ji YuPeng Xu JingKang Deng RenCheng Shang GuoQing Liu FangJun Lu ShuangNan Zhang YongWei Dong TiPei Li Mei Wu YanGuo Li HuanYu Wang BoBing Wu YongJie Zhang Zhi Zhang ShaoLin Xiong Yuan Liu Shu Zhang HongWei Liu YiJung Yang Fan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China University of Chinese Academy of Sciences Beijing 100049China

The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.

关键词： X-ray telescope HXMT calibration scintillation detector