Browsing by Author "Yu, TC"

Now showing 1 - 3 of 3

Chaos synchronization of a horizontal platform system
(2003-12-04)
Ge, ZM
;
Yu, TC
;
Chen, YS
;
機械工程學系
;
Department of Mechanical Engineering
Chaos and chaos synchronization of the horizontal platform system are studied in this paper. Because of the non-linear terms of the systems, the systems exhibit both regular and chaotic motions. By applying various numerical results, such as phase portraits, Poincare maps, time history and power spectrum analysis, the behaviors of the periodic and chaos synchronization are presented. The effects of the change of parameters in the system can be found in the bifurcation diagrams. Chaos synchronization of feedback methods in two coupled systems has been studied by Lyapunov exponent and coupling strength. Besides, phase effect of external excitations and the transient time in unidirectional synchronization also have been researched. (C) 2003 Elsevier Science Ltd. All rights reserved.
Substrate bias effect on amorphous hydrogenated carbon films deposited by filtered cathodic arc deposition
(2001-11-01)
Li, YW
;
Chen, CF
;
Shue, YB
;
Yu, TC
;
Chang, JJK
In the present study, we briefly describe the 45 degrees angle magnetic filtered arc deposition (FAD) process and investigate the effect of substrate bias on the hardness of amorphous carbon (a-C) films. An attempt is made to correlate the microstructure. chemical composition and chemical bonding states with the hardness of the corresponding films. After deposition. the film properties v,ere analyzed by Raman spectroscopy and nanoindentation system (NIS). It was found that amorphous carbon films possess highest hardness when deposited at substrate biases ranging from -50 V to -100 V. The hardness values do not show good correlation with Raman I(D)/I(G) ratio. Hydrogen additions to the system help prevent the nucleation of the graphite phase, and stabilize the sp(3) bonding of amorphous hydrogenated carbon films. Hydrogen affected on the small graphitic crystalline growth. Films have higher hardness when they have higher fraction of sp(3) content.
Substrate bias effect on amorphous nitrogenated carbon films deposited by filtered arc deposition
(2002-03-01)
Li, YW
;
Shue, YB
;
Chen, CF
;
Yu, TC
;
Chang, JJK
The effect of substrate bias and nitrogen incorporation on the structure and hardness properties of amorphous carbon (a-C) films is characterized in terms of its composition, sp(3) bonding fraction, and Raman spectra. The films' properties were analyzed using Raman spectroscopy, Auger electron spectroscopy (AES), and nanoindentation system (NIS). Experimental results indicate that a-C films were found to possess the highest hardness when deposited at a substrate bias ranging from -50 to -100 V. In addition, the hardness values do not correlate well with the Raman I(D)/I(G) ratio. The hardness of films increases with their sp(3) bonds fraction. Furthermore, nitrogen content increases with increasing substrate bias on amorphous nitrogenated carbon (a-C:N) films, and influences the growth of small graphitic crystallines. (C) 2002 Elsevier Science B.V. All rights reserved.