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As an Elastic memory composite (EMC) laminate is bent, the prebuckled plate theory is valid until the transition curvature at which point the postbuckled solution becomes effective. This is the point at which microbuckling is predicted to occur. From the point onward, EMC laminate follows the postbuckled solution. In this paper, a solution of the transition curvature is proposed by combining matrix shear energy with Timoshenko’s elastic foundation energy. By comparing with the intersection point of the straight line given by the prebuckled plate theory and the curve given by the postbuckled solution, the solution can be used to predict the point at which microbuckling is predicted to occur.

Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of [Bi.sub.2][Te.sub.3] with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that [Bi.sub.2][Te.sub.3] is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of [Bi.sub.2][Te.sub.3] also points to promising potential for high-temperature spintronics applications.

Measurements for photorefractive dynamic properties under polarized light with different luminous intensity and wavelength at 650 nm were performed in calcium-doped strontium barium niobate crystals as a function of the time. Experimental results further validated that the different input luminous intensities influence only the saturated time and photorefractive velocity of the photorefractive crystals. Birefringence experiments suggest that an input luminous intensity oscillatory threshold should exist between 64 mW/[cm.sup.2] and 13 mW/[cm.sup.2]. The dynamic change of refractive index from self-focusing to asymmetric self-defocusing was also measured and regarded as the mutual results of the nonuniform-intensity incidence and positive thermal lens effect, which was validated by a further experiment based on the Michelson interference. Also, oscillation accompanying change in the dynamic indices was analyzed and attributed to the high dielectric effect as well as asymmetric self-defocusing in this investigation. OCIS codes: 160.5320, 260.1440, 190.0190.

A diode-pumped Yb:YCOB laser at 1086 nm is passively Q switched by using InGaAs quantum wells as saturable absorbers and utilizing the Bragg mirror structure as an output coupler. With an absorbed pump power of 9.2 W the laser produces pulses of 100 ms duration with average pulse energy of as much as 165 [micro]J at a pulse repetition rate of 7 kHz. OCIS codes: 140.0140, 140.3540, 140.3580.

Vortices shed from the tip of a rectangular half-span wing model (NACA 0012) have been investigated with particle image velocimetry at a chord Reynolds number between 3.4 x [10.sup.4] and 26.6 x [10.sup.4] and angles of attack [alpha] = 8 and 16 deg over 0.2 ~ 5 chord lengths downstream of the model. It has been found that the measured wing-tip vortex shows little dependence in the circumferential velocity [v.sub.[theta]] and vorticity [OMEGA], when normalized by their local maximum, on [alpha], Reynolds number, and downstream distance from the wing. Furthermore, the radial distributions of [v.sub.[theta]] and [OMEGA] coincide quite well with the exponential vortex solution, with only a slight departure outside the core region.