Browsing by Author "Hsu, F. C."

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Excited Energy Attenuation Study Through Vibration Measurement and Spectrum Analysis
(2010)
Lin, S. Y.
;
Chang, C. K.
;
Chung, C. T.
;
Hsu, F. C.
;
Wang, C. C.
This paper presents the use of vibration measurement in conjunction with spectrum signal analysis to investigate the vibration phenomena and the dynamic response of the absorber system frame and rigid axle of a vehicle body under real road-driving conditions. Ford 1.6L sedan was selected as the vehicle body to carry out the experiments with different driving speeds. B&K PULSE dynamic signal analyzer was used to detect the vibration signal induced from the absorber system frame and rigid axle of the vehicle body in motion. The acquired on-line signals are then processed through the Fast Fourier Transform using the power spectrum density, the cepstrum method, and the overall analysis. The vibration energy attenuated from the absorber system is analyzed by comparing with that on the rigid axle excited from the road conditions corresponding to different driving speeds. Furthermore, the effects of various road conditions and driving speeds on oscillation of the vehicle body are studied. The corresponding results may be extensively treated as a guiding reference of the absorber system design and manufacturing for those vehicle manufacturing companies.
Orbital polarization of the unoccupied states in multiferroic LiCu(2)O(2)
(2008-12-01)
Chen, C. L.
;
Yeh, K. W.
;
Huang, D. J.
;
Hsu, F. C.
;
Lee, Y. C.
Using measurements of polarization-dependent soft-x-ray absorption and band-structure calculations including the on-site Coulomb interaction, we investigated the symmetry of the intrinsic 3d holes in the low-dimensional quantum magnet LiCu(2)O(2) with edge-sharing spin chains. The Cu L-edge and O K-edge measurements with in-plane and out-of-plane E vectors of x ray reveal the orbital character of the valence states of Cu on different sites. The unoccupied 3d states of nominal Cu(2+) exhibit predominantly xy symmetry, whereas 3d holes of 3z(2)-r(2) symmetry reside on the nominal Cu(+) sites. Both the experimental observations and theoretical calculations agree on the hybridization of the O 2p and Cu 3d states above the Fermi level. The existence of 3d holes on Cu(+) enhances the interlayer magnetic coupling.
Orbital polarization of the unoccupied states in multiferroic LiCu2O2
(2008-12-01)
Chen, C. L.
;
Yeh, K. W.
;
Huang, D. J.
;
Hsu, F. C.
;
Lee, Y. C.
Using measurements of polarization-dependent soft-x-ray absorption and band-structure calculations including the on-site Coulomb interaction, we investigated the symmetry of the intrinsic 3d holes in the low-dimensional quantum magnet LiCu2O2 with edge-sharing spin chains. The Cu L-edge and O K-edge measurements with in-plane and out-of-plane E vectors of x ray reveal the orbital character of the valence states of Cu on different sites. The unoccupied 3d states of nominal Cu2+ exhibit predominantly xy symmetry, whereas 3d holes of 3z(2)-r(2) symmetry reside on the nominal Cu+ sites. Both the experimental observations and theoretical calculations agree on the hybridization of the O 2p and Cu 3d states above the Fermi level. The existence of 3d holes on Cu+ enhances the interlayer magnetic coupling.