Rayleigh-Taylor instability problem is simulated by using discontinuous finite element method which is developed for Euler equations with an additional body force corresponding to the gravity. Level set method for capturing moving interfaces and ghost fluid method with Isobaric fix for disposing the interfaces are used. Through two representative numerical examples of Rayleigh-Taylor instability, it can be concluded that this method has capability to solve multi-media fluid problems including contact discontinuous, without numerical oscillation near the interface and high resolution.

The 3D computational method and technique were studied by coupling SPH algorithm to rigid body solution. Based on the new method and technique, and combining with the Johnson-Cook, Johnson-Holmquist contitutive models, as well as the existing 3D synthetical Lagrangian finite element code CL3D, a new 3D Lagrangian code CRSPH3D was written out. The new code, CRSPH3D, is suitable to be used in the numerical simulation of the 3D problems of rigid projectile penetrating thick targets. The new code was applied to numerically simulate the processes of both rigid projectiles normally and obliquely impacting and perforating aluminum targets and rigid projectiles normally and obliquely impacting and penetrating thick concrete targets. For the problems of projectiles perferating aluminum targets, the simulation results gave good agreement to the experimental ones. And for the problems of projectiles penetrating concrete targets, the obtained results from simulations were qualitatively reasonable.

The knowledge of the thermodynamic equation of state of fluid water plays an important role in understanding of many phenomena within the purview of the earth and planetary sciences. However, data are sparse in the high temperature and high pressure region and most equations of state for water, at high pressures, rely heavily on extrapolation of data or calculations of molecular dynamics. This paper presents the acoustic velocity of water measured by Brillouin scattering technique at different temperature and pressure, and compares the velocity with those predicted by the equations of state. Our measured velocities of water are lower than those predicted by Saul and IAPWS-95, while they are the same as those predicted by Abramson within 6.0 GPa and 673 K; on the other hand, at 21 GPa and 890~1 100 K conditions, the measured velocities are higher than those predicted by all the three equations of state.

We applied the Brillouin scattering and diamond-anvil cell (DAC) technique to study the liquid oxygen at high pressure and high temperature. The single-frequency green (532 nm) laser was used as Brillouin excitation source, and the Brillouin spectra were collected by a newly developed 3+3 pass tandem Fabry-Perot interferometer. The sample was loaded into a modified Merrill-Bassett-type four-screw DAC and heated externally by a resistance heater. The backscattering and 60° scattering geometries were used simultaneously. In this paper, we presented the pressure dependences of sound velocities of liquid oxygen under high pressure and high temperature, and the results were consistent with those predicated by theoretical calculations. The elastic constants of liquid oxygen were determined under high pressure and high temperature, we suspected that the volume of liquid oxygen doesn't expend with temperature under the pressure range from 2.3 GPa to 4.9 GPa.

The computation of underwater explosion model with a gas-water interface is discussed where the interface is considered as a special internal boundary. This boundary is represented as doubled-defined points and each point corresponds to one material. The HLLC (Harten, Lax, van Leer, Contact) scheme is implemented in solving ALE (Arbitrary Largrangian-Eulerian Method) formulation on unstructured moving grids to track the material interface. This method is used to compute 1D spherical symmetric underwater explosion model and the solution agrees with the experiment data well. As an expansion, 2D cylindrical underwater explosion model is also computed and a satisfying result is obtained.

On the basis of multi-fluid volume fraction (VOF) and piecewise parabolic method (PPM), a multi-fluid hydrodynamic program MFPPM (Multi-Fluid Piecewise Parabolic Method) was developed and performed to study the Richtmyer-Meshkov instability of gas/liquid interface. The influences of initial perturbations and grids on the fluid mixing zone (FMZ) were mainly researched when it is accelerated by shock waves, and the FMZ width, bubble and spike height growing with time were presented simultaneously. By comparing the computational results, it shows that the initial perturbations affect the FMZ growth rate extremely, especially at late times. The evolution of spike is similar to the FMZ, the bubble height increases linearly with time basically, and influenced little by initial perturbations, but the configuration is quite different, and as the effect of grid size is.

The in-situ angle dispersive X-ray powder diffraction of natural pyrope collected from Zhenyuan in China using synchrotron radiation has been measured under high pressure (0~25.3 GPa) conditions with diamond anvil cell (DAC). We have not found any convincing evidence for a phase transformation in the experimental pressure range. The XRD patterns were then refined by using the refinement module combined in the Materials Studio program. We fit the Birch-Murnaghan equation of state and obtained its ambient pressure bulk modulus B₀=199 GPa (B′₀=4).

Boron nitride (BN) thin film on diamond film substrate was synthesized by radio frequency (rf) magnetic sputtering physical vapor deposition. The field emission characteristics of diamond film and BN coated diamond film were measured in an ultrahigh vacuum system. Experiments demonstrate that BN film is effective in improving the field emission characteristics of diamond film. The threshold electric field is 12 V/μm and highest emission current density is 272 μA/cm² for the BN coated diamond film. The Fowler-Nordheim plots show that electron emission is due to tunneling over a barrier.

Homogeneous submicron PZT 95/5 powder was synthesized from the mixtures of Pb₃O₄, ZrO₂ and TiO₂ with Nb₂O₅ as an additive by a planar shock wave-loading device. The impact velocities of flyer plates on sample targets were adjusted by their thickness to obtain different shock conditions and to achieve the synthesis of PZT 95/5 powders in experiments. The analyses of XRD and SEM show that the shock-synthesized samples obviously became fine, and heavy distortion and many defects of lattices were formed in the process of shock compression.

The effects of high pressure and heat treatment on microstructure of aluminum bronze were investigated by means of metallographic, scanning electronic microscope (SEM)/energy disersive spectrometer (EDS) and X-ray diffraction (XRD). Results showed that the grain size of α phase in the aluminum bronze after the treatment at 750 ℃ and 6 GPa high pressure is smaller than that after treatment at 750 ℃ and normal pressure. When the aluminum bronze was treated at 750 ℃ and 6 GPa and followed by a treatment at 750 ℃ for 2 min, thin stripy α phase occurred in the aluminum bronze, and its amount increased but the amount of granular α phase decreased with increase of the cooling rate.