空间科学学报

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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Interference Analysis on Q/V Band ISL between NGSO Constellation Systems

ZHANG Zhao, YAO Xiujuan, GAO Xiang, ZHI Jia, WANG Jing

, Available online , doi: 10.11728/cjss2023.01.220302023

Abstract(20) FullText HTML (6) PDF 1677KB(2)

Abstract:
With the development of large-scale constellation system, low-Earth-orbit space frequency orbit resources are increasingly scarce. The subsequent risk of space-borne communication link interference cannot be ignored, and it becomes one of the key indicators to be considered in the future constellation system design. On the premise of avoiding interference, it is crucial to ensure the working performance of constellation system. Intersatellite link has great interference risk in large scale NGSO constellation systems. To solve that, the interference avoidance methods based on the interfering and interfered angle are proposed. Taking the Starlink with Q/V band as an example, the working efficiency and anti-interference efficiency of the system are defined, and the robustness of the system under different interference avoidance methods and chain building strategies is studied. Simulation results show that the interference avoidance based on the interfered angle can reduce the I/N overrun time ratio from 5.79% and 16.75% to 0 respectively under different link building strategies, without affecting the working link. This simulation method can be a reference for large-scale NGSO constellation interference avoidance with intersatellite links.

Effect of Prolonged Fasting on Uric Acid Metabolism and Its Regulation Mechanism

SUI Xiukun, GUO Zhifeng, ZHANG Hongyu, WANG Hailong, WU Feng, YANG Chao, GUO Yaxiu, MA Ting, LI Yinghui, DAI Zhongquan

, Available online , doi: 10.11728/cjss2023.01.220225021

Abstract(49) FullText HTML (24) PDF 2642KB(3)

Abstract:
To investigate the changes of uric acid metabolism in rats during prolonged fasting and its potential regulatory mechanism. Sprague-Dawley (SD) rats were used as animal models. The changes of uric acid level and metabolism-related gene and protein expression in rats during different fasting periods (1, 2, 3, 5, and 7 days) were analyzed by pathological tissue sections, biochemical tests, quantitative PCR (qRT-PCR), and western blotting. The results showed that prolonged fasting did not cause significant damage to kidney tissue, but remarkedly increased the blood uric acid level and blood uricase activity. It also resulted in fluctuating changes in urine uric acid level. The mRNA and protein expression levels of main uric acid transporters were increased gradually with the fasting duration. The elevation of serum uric acid caused by prolonged fasting is related to uric acid transporter and uricase activity.

Clustering of Ultraviolet Auroral Oval Images Based on Deep Representation Learning

ZHANG Lingshu, ZOU Ziming, BAI Xi

, Available online , doi: 10.11728/cjss2023.01.220127012

Abstract(17) FullText HTML (8) PDF 1726KB(3)

Abstract:
Aurora is affected by large-scale dynamics such as geomagnetic substorm driven by solar wind, due to varies solar wind-magnetosphere-ionosphere coupling effects, its morphology and evolution can be different. Currently, categorization of aurora oval and its morphology is mostly based on auroral evolution theory to do subjective qualitative analysis and has no clear classification standard, which makes it challenging to conduct objective quantitative research with statistical analysis method and supervised classification models. Ultraviolet (UV) auroral oval image clustering model (MoCo-GMM) was established based on deep representation learning, also a method was designed to evaluate physical rationality of the model by using space environment parameters. Additionally, experiments on large-scale POLAR UV auroral oval image data were carried out. Clustering results of MoCo-GMM obtained not only delightful intra-cluster cohesion and inter-cluster separation, but a certain degree of physical interpretability, which means we effectively realized objective categorization of aurora oval and its morphology based on images.