  We explore the quasi-periodic pulsations (QPPs) with multiple periods in hard
X-ray (HXR) emission from Fermi/GBM during the impulsive phase of solar flare
(SOL2014-09-10). The completely new observational result is that the shorter
periods appear at lower energies of the X-ray photons at the beginning and the
longer periods appear at higher energies at the end, with some intersection of
the periods at medium energies. We also find the shorter and then the longer
periods during the same phase of this flare. Using the wavelet power spectrum
and fast Fourier transform (FFT) spectrum, we analyze the normalized rapidly
varying signal divided by its slowly varying signal, which is the smoothed
original HXR flux. The periods of 27 s and 37 s are derived at lower energy
channels between 17:25 UT and 17:29 UT, i.e., 12.0-27.3 keV and 27.3-50.9 keV.
Then the periods of 27 s, 46 s and 60 s are observed at medium-energy channel
from 17:26 UT to 17:33 UT, such as 50.9-102.3 keV. And the period of 80 s is
detected at higher energy channel from 17:28 UT to 17:33 UT, such as
102.3-296.4 keV.
