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In this study, 1 216 consecutive days of ESA precise clock products (January 2022 to April 2025) were analyzed by combining clock-fit parameters, frequency-stability metrics, and spectral analysis to assess the long-term behavior of the onboard clocks. Results show that E14 experienced three phase jumps and two frequency jumps during this period, more frequently than nominal circular-orbit satellites. Following the frequency jump in April 2024, its frequency drift and fitting accuracy deteriorated markedly: residual peaks exceeded 10 ns, and an anomalous periodicity of about 0.63 h emerged with increasing amplitude and no evident secondary component. The frequency stability simultaneously worsened, showing oscillatory behavior near 100 s. After another frequency jump in March 2025, both residuals and stability improved, with stability reaching 2.50×10-13, 6.52×10-14, and 9.70×10-14 at 100 s, 1 000 s, and 10 000 s, respectively. No dominant periodic term was observed afterward, but the drift exhibited a systematic bias, and a "dip" feature appeared near 4 000 s. In contrast, the co-orbital E18 satellite maintained stable performance throughout the same period, with fitting residuals confined within ±0.2 ns, no significant high-frequency periodic components, and frequency stability comparable to that of nominal MEO satellites, showing no anomalous behavior.
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| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
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