Online First

Online First have been peer-reviewed and accepted, which are not yet assigned to volumes/issues, but are citable by Digital Object Identifier (DOI).
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Investigation on Performance Difference of 35 K Cryogenic Heat Transfer System in Ground and Space Environment
GUO Yuandong, LIU Sixue, ZHANG Hongxing, MIAO Jianyin, ZHAO Jianfu, LIN Guiping
, Available online  , doi: 10.11728/cjss2024.01.2023-yg13
Abstract:
In order to solve the problem of cryogenic heat dissipation of space infrared detection system and ensure its cryogenic operating environment, an integrated system of cryogenic acquisition and heat transfer in 35 K temperature range was designed and developed based on pulse tube cooler and cryogenic loop heat pipe. The system consists of a neon cryogenic loop heat pipe, two sets of pulse tube cooler in 35 K temperature range, one pulse tube cooler in 150 K temperature range, thermal insulation screen, temperature measurement / heating components, control system. It has completed ground single-level and satellite-level thermal vacuum tests, and completed space flight tests in 2020. Heat transfer tests under horizontal attitude and anti-gravity conditions were carried out in the ground stand-alone test to ensure that the system could work stably in space microgravity. The whole-satellite test verified the working characteristics of the system under the heat dissipation condition of the satellite platform, and the space flight test obtained the working performance of the system under space microgravity. This paper introduces the thermal performance of the system in different stages, including supercritical start-up characteristics, steady-state operation performance, etc. The results have verified the correctness of relevant design, and this paper focuses on comparing the performance differences in different stages, and analyzes the possible reasons.
Seasonal Variations of Global Ionospheric NmF2 and hmF2
LI Bo, CUI Ruifei, WENG Libin
, Available online  , doi: 10.11728/cjss2024.01.2023-0130
Abstract:
The seasonal variations of global ionospheric NmF2 and hmF2 have been analyzed by using the monthly COSMIC ionospheric data from 2006 to 2019 and wavelet analysis method. The results show that the ionospheric NmF2 and hmF2 are significantly different with local time, season and latitude. The ionospheric peak parameters have positive correlation with the solar activity, and their correlation coefficients are above 0.9 and 0.8, respectively. The ionospheric NmF2 at noon exists significantly annual and semiannual variations, especially under the high solar activity conditions. However, the annual variation of ionospheric NmF2 has been mainly observed at nighttime. Meanwhile, the annual variation of ionospheric hmF2 at noon is significant in all years, but almost absent during midnight. Additionally, and the seasonal variations of ionospheric NmF2 and hmF2 in the southern hemisphere are more obvious than that in the northern hemisphere. Additionally, the seasonal variations of ionospheric peak parameters are more significant during high solar activity years. Moreover, there seem to be periodic signals of 25~35 months in the solar activity index and ionospheric peak parameters, but their power spectrum are not greater than 95% significance level, and we thought that the ionosphere would be not affected by the QBO signal.
Progress on Exoplanet Detection and Research in Space
ZHOU Jilin, XIE Jiwei, GE Jian, JI Jianghui, DOU Jiangpei, DONG Subo, LIU Huigen, WANG Wei, GUO Jianheng, YU Cong, BAI Xuening, FENG Fabo, LIU Beibei
, Available online  , doi: 10.11728/cjss2024.01.2024-yg01
Abstract:
The subject of exoplanets has been a rapidly developing discipline in the past thirty years. Its main research content and objectives include: detecting exoplanets through the development of various detection techniques, analyzing planetary orbits, composition and atmospheric properties, evaluating the habitability of planets, calculating the distribution patterns of planets, and revealing the formation and dynamical evolution of planetary systems from both theoretical and observational perspectives. The study of exoplanets is of great significance in answering questions about the existence of other life forms in the universe and the status of humans in the universe. With the development of space exploration technology in the 21st century, the study of exoplanets has entered a new era. This article summarizes the development trend in the field of exoplanets, condenses China's key areas for future space exploration of exoplanets, optimizes the discipline layout, and promotes high-quality development of exoplanet research.
Laboratory Thermal Emission Spectral Measurement and Calibration Methods for Planetary Science Research
YANG Yazhou, MILLIKEN Ralph E, BRAMBLE Michael S, PATTERSON William R, ZOU Yongliao, LIU Yang
, Available online  , doi: 10.11728/cjss2024.01.2023-0116
Abstract:
Accurate information regarding the surface composition is crucial for understanding the formation and evolution history of planetary bodies. Visible and near-infrared remote sensing spectroscopic techniques have long been used for the detection of surface composition. However, in the thermal infrared spectral range, various types of planetary surface materials exhibit richer spectral features. With the development of thermal emission spectroscopic techniques, it has been increasingly used in planetary exploration. Particularly, in the ongoing and planned asteroid exploration missions, thermal emission spectrometers are employed as key payloads. In order to better interpret the thermal emission spectral data to be obtained in the future, it is essential to establish scientifically reasonable data processing and calibration schemes. This paper provides a comprehensive overview on the design of thermal emission spectral measurement devices for planetary science research, the measurement process, and data reduction methods. To obtain accurate emissivity spectra data, the challenge of distinguishing sample radiation signals from instrument radiation during thermal emission measurements must be properly addressed first. Especially, for measurements conducted under low-temperature and vacuum conditions that are similar to the surface conditions of the Moon and asteroids. This paper proposes and demonstrates a data reduction method based on interferograms, which are the original signals measured by FTIR spectrometer. This method can effectively separate the actual radiation signal from the samples, thus yielding more accurate emissivity spectra data. The insights derived from this study can serve as valuable references for the development and construction of thermal emission measurement devices and can facilitate the processing and scientific interpretation of data from future missions such as Tianwen-2.