The present paper gives an analysis of the lowfrequency (LF) vortex and divergent circulation systems and their interactions in terms of the ECMWF/WMO data (summer of 1984).
The ratio of the lowfrequency to high frequency components in HRV power spectrum(LF/HF) fluctuates with the change in the sleep stages.
HRV频谱中低频和高频成分的比值(LF/HF)随着睡眠深度的变化而波动。
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In terms of operation frequency, RFID systems can be divided into four categories: lowfrequency (LF), high frequency (HF), ultra high frequency (UHF), and microwave.