In this paper, the data of 140 earthquakes recorded at different azimuths from the Beijing network are used. By using both the smoothing method and dT/d△ method, the slowness curves of P-wave are obtained.

In this paper, the elastic constant matrix for anisotropic carbon fiber-reinforced (CFR) material is given by the measurement of ultrasonic wave velocities. According to this matrix and the characteristic equation for anisotropic solids, the slowness curves for this material are obtained.

After careful design and adjustment of the experiment system. Brillouin spectra of LiNbO3 crystals were measured in the 90° scattering scheme. We measured all independent elastic and piezoelectric constants of LiNbO3 crystals made in China in the hypersonic region.

The stiffness C13 was estimated by iteration so that the slowness curve of quasi-shear waves computed to an assumed C13 best matches the measured one.

The SAW slowness curve is elliptical for Y- or Z-cut crystal wafers, and circular for an X-cut wafer.

This condition, which can also be deduced on the basis of the erosion slowness curve, leads to a higher degree algebraic equation with a parameter, applicable for any dependence S=S (θ), expressed as an algebraic polynomial expression in cos θ.

The two-dimensional slowness curves corresponding to different rotations are presented graphically.

The theoretical calculations of slowness curves are in good agreement with experimental results.

In this paper, the data of 140 earthquakes recorded at different azimuths from the Beijing network are used. By using both the smoothing method and dT/d△ method, the slowness curves of P-wave are obtained. By incorporating the travel-time and slowness data, continuous travel-time curves can be obtained. A simpler formcla than Gerver-Marku-shevish's formcla is derived and used to invert the intial veloctity models. Through computing theoretical travel-time curves of th initial velocity models, the final velocity...

In this paper, the data of 140 earthquakes recorded at different azimuths from the Beijing network are used. By using both the smoothing method and dT/d△ method, the slowness curves of P-wave are obtained. By incorporating the travel-time and slowness data, continuous travel-time curves can be obtained. A simpler formcla than Gerver-Marku-shevish's formcla is derived and used to invert the intial veloctity models. Through computing theoretical travel-time curves of th initial velocity models, the final velocity models which agree better with the observational data are obtained. The average velocity model shows that: a shallow low velocity zone begins near 60 km in depth: two abroupt increases in velocity from 360 to 420 km and from 660 to 680 km are also obtained; a possible minor zone of high-velocity gradient near 500 km is detected. Differences in depth of the zone of 600 km between the south-east and south-west directions in Northern China can clearly be seen.

In addition to pboto-elastic effect, we have also considered rotation and electro-optic effects in calculating Brillouin tensors of LiNbO3 crystals. After careful design and adjustment of the experiment system. Brillouin spectra of LiNbO3 crystals were measured in the 90° scattering scheme. We measured all independent elastic and piezoelectric constants of LiNbO3 crystals made in China in the hypersonic region. The spatial were also measured in the 180?back scattering scheme. Experimental results are in good...

In addition to pboto-elastic effect, we have also considered rotation and electro-optic effects in calculating Brillouin tensors of LiNbO3 crystals. After careful design and adjustment of the experiment system. Brillouin spectra of LiNbO3 crystals were measured in the 90° scattering scheme. We measured all independent elastic and piezoelectric constants of LiNbO3 crystals made in China in the hypersonic region. The spatial were also measured in the 180?back scattering scheme. Experimental results are in good agreement with calculations.

Recently we have investigated two-dimensional generalized Green's functions for surface excitation in a half space of piezoelectric crystal. In this paper, the SAW part of generalized Green's functions are discussed in detail. On using the method of stationary phase, the asymptotic behavier of SAW far fields is obtained. But, since such asymptotic solutions near the turning points of slowness curve fail, the general asymptotic solutions expressed by a varied Airy function are developed. And the joining problem...

Recently we have investigated two-dimensional generalized Green's functions for surface excitation in a half space of piezoelectric crystal. In this paper, the SAW part of generalized Green's functions are discussed in detail. On using the method of stationary phase, the asymptotic behavier of SAW far fields is obtained. But, since such asymptotic solutions near the turning points of slowness curve fail, the general asymptotic solutions expressed by a varied Airy function are developed. And the joining problem of solutions near the turning points can be resolved.