The influence of H in using Li₃N as catalyst on the synthesis of cBN under high-temperature and high-pressure has been investigated. From the observation of cBN crystals growth within the sample capsule, the temperature gradient distribution has been discussed.

The pressure effects on the band structure of bcc lithium with substitutional hydrogen defect are studied by using ab initio pseudopotential-plane wave method at 0 K temperature. Even though the impurity hydrogen atom localizes a free electron in the sea of metallic valence electrons, the doped system still acts as metal, but an isolated band and a band gap appear under Fermi level, the lowest metallic band is distorted at Gamma point, and elsewhere in other conduction and valence bands. When pressures applied on the system, the band gap is widened and the isolated band tends to be stretched horizontally into a line, just like an energy level.

With the application of Rubin's penetration theory and the velocity potential model, some new results of penetration problem are presented in this paper. A code according to this model was written to calculate penetration problems of long rod projectile with conical-nose, ogive-nose and spherical nose. The results of penetration depths and residual velocity were compared with the experimental data to analysis the adaptability of the model to varied kinds of noses. The comparison showed that the results given by the theoretical penetration model are in good agreement with the experiments for ogive-nose rod projectile. Then we used the theoretical penetration model to study the scaling penetration problems of ogive-nose projectile impacting on aluminum targets. The calculated results testified the conclusion that the normalized penetration depths and residual velocity are equal. Meanwhile we drew an important conclusion that the deceleration of the projectile are inverse proportion to the size. Finally, using the theoretical model, we made a trial to calculate penetration problems of the concrete targets, presented some results consistent with the experiments, and gave a delicate analysis.

We have applied the combination of PPM and VOF methods with Lagrange-Remapping algorithm for simulation of the various cavities compressed by the high pressure loading. The physical processes of the multi-fluid interactions are calculated in high accuracy. This method also shows the potential for dealing with the problems of high density or high pressure ratio flows.

A thermo-visco-plastic constitutive relation for the metal, which can cover plastic hardening (softening) behaviors, thermo-softening behaviors and damage-softening behaviors, is adopted in the numerical computation for analyzing the metal spallation induced by laser. Computations are carried out in one-dimensional and two-dimensional cases, respectively. Attenuation of shock wave pressure is calculated, as well. The calculated spallation thickness is in good agreement with the experimental observations.

The electrical conductivities of the iherzolite were measured by virtue of SARLTON-1260 frequency and phase impedance spectroscopy analyzer in situation of 1.0~4.0 GPa, 1 073~1 573 K and 10^-1~10⁷ Hz frequency ranges. The experimental results indicate that the complex impedance spectra of iherzolite strongly depends on frequency, at the same time we explain it by virtue of electrical conduction: grain boundaries, grain interiors as well as between sample and electrode; the temperature is an important parameter deciding the electrical conductivity. As temperature increases, the electrical conductivity augments. The relationships between lg σ and 1/T accord with Arrenhius relation formula; this is the first time that the pressure as a controlling ingredient is well brought forward: As the pressure increases, the block rate advances; at the same time the electrical conductivity decreases.

The sound velocities of longitudinal wave and transverse wave for LY12Al were measured under static pressures using “pulse echo overlap technique”. According to the bulk modulus at zero pressure, K_S0, and its pressure derivative K′_S0 yielded from the ultrasonic meansurements under very low pressures (<0.5 GPa), three Isothermal Equations of State—Murnaghan EOS, Birch-Murnaghan EOS and Vinet EOS for LY12Al were reduced. It was found that the Vinet EOS deduced from ultrasonic data was adequate for describing the compressibility of aluminium and its alloy with fcc structure, even up to 200 GPa. Furthermore, the zero pressure Debye temperature and thermodynamic Grüneisen parameter calculated from the ultrasonic data for LY12Al are 430.97 K and 2.025, respectively.

The physical properties of diesel oil are the base of simulating high pressure fuel injection system, where the pressure and temperature fluctuation are significant. The density, bulk modulus, kinematic viscosity and vapor pressure of diesel oil are studied by experiments in this paper, from which the density, bulk modulus and kinematic viscosity variations with the pressure and temperature are abstracted. The errors between the calculation data and tested data are less than 3%, and its correlation coefficients are higher than 0.998. The obtained experimental functions have satisfied the high precision requirement for simulation of the fuel injection system.

Under the circumstances of magnetic field, high pressure and high temperature, the influence of the electron-spin on the self-trapping energy of the weak-coupling 2-D magnetopolaron was studied by using unitary transformations and the linear combination operator method. Numerical calculation, with InAs semiconductor as an example, illustrated that the self-trapping energy level of the weak-coupling 2-D magnetopolaron was divided into two by the electron-spin of different direction. The split self-trapping energy level was more marked with increasing magnetic field. The self-trapping energy of the magnetopolaron decreased and the ratio of electron-spin energy to the self-trapping energy of the magnetopolaron increased with increasing magnetic field or temperature. The ratio of electron-spin energy to the self-trapping energy of the magnetopolaron was very large, when the magnetic field performed sufficient strong and the temperature performed sufficient high.

A previously proposed approximate quasi-static theoretical method is employed herein to examine the deformation and perforation of a simply-supported circular plate struck by a flat-faced projectile at normal incidence. Based on the principle of virtual work, static load-displacement relationships are first obtained and then used to predict the energy-absorbing capacity of the plate subjected to relatively low speed impact. It is shown that good agreement is obtained between the theoretical predictions and the available experimental data, provided that adiabatic shear plugging failure does not occur, but the influence of strain rate sensitivity is taken into account.