  Based upon a phenomenological $t-t'-U-V$ model and using Bogoliubov-de Gennes
equations, we found that near the optimal doping $\delta=0.15$ at low
temperature ($T$), only the pure d-wave superconductivity (dSC) prevails and
the antiferromagnetic (AF) order is completely suppressed. However, at higher
$T$ the AF order with stripe modulation and the accompanying charge density
wave (CDW) emerge, and they could exist even above the superconducting
transition temperature. This implies that the existence of the CDW depends
critically on the presence of the AF order, not so much on the dSC. The LDOS
(local density of states) image indicates that the stripe modulation has an
energy independent spacing of $5a/4a$ spreading over a $24a \times 48a$
lattice, corresponding to an average periodicity $4.8a$. This result may be
relevant to the recent STM experiment [Vershinin $et al.$, Science {\bf 303},
1995 (2004)].
