During testing low impedance materials (so-called soft materials) by a conventional split Hopkinson pressure bar (SHPB), the transmission strain pulse is too weak to be collected correctly. In addition, the soft material specimen will not deform homogeneously during the testing, which makes it impossible to get valid data. In this paper, a polyurethane foam material was tested by SHPB using a quartz transducer technique. The stress equilibrium in the specimen was monitored by quartz transducer mounted at two end faces of the specimen. Experimental results showed that the amplitude of transmitted signals were increased greatly. Meanwhile, we used a pulse-shaper technique to increase the rise time of the incident pulse, which could ensure stress equilibrium and homogeneous deformation in the specimen. Compressive stress-strain behaviors of the foam showed that there was little effects of strain rates on the material properties at strain-rate of 1 000~4 000 s^-1.

After up to 10 generations of purification by strict self-fertilizing, seeds of two rice varieties (Oryza sativa L.), Yuexiangzhan and Bijing-38 were treated with high hydrostatic pressure during last 5 years, and 5 contemporaneous mutants and 4 descendant natural mutants were obtained with high reproducibility for the contemporaneous mutants. To verify if the mutation was take place at DNA level, Inter Simple Sequence Repeat (ISSR) analysis of the original rice varieties and mutants was conducted. The analysis revealed that the genetic substance (DNA) had been altered. Evidently, the mutation was induced by high hydrostatic pressure treatment. Generally, the mutation took place contemporaneously and the new characters are of high genetic stability; the further the genetic distance between the mutant and the original is, the higher the genetic stability of the mutant is.

The spallation experiments of Al-Li alloy have been carried out and the free surface velocity temporal curves for the spallation events have been measured. Based on the microscopics statistics and phenomenological analysis, a damage evolution equation is developed, which involves the effects of the growth and nucleation of microcavities as well as the effects of the material's compressibility. Inserting the constitutive equation and Murnagham state equation of Al-Li alloy and the damage evolution equation into ANWP, which is a special program for one-dimension strain wave, and by the numerical simulation of the free-surface velocity temporal curve for the spallation events in the gas gun experiments, we have obtained the related parameters in the damage evolution equation and the spallation criterion.

The deformation and spalling behavior of the cylindrical steel tube under external explosive loading was studied. On the basis of the damage evolution equations and considering damage and temperature softening effects, we obtained the explicit plastic constitutive relations. Numerical simulations were carried out and the computational results were analyzed. The satisfactory agreement between the computational results and the experimental ones shows that the constitutive relations and computational method presented in this paper are reasonable and of important in practical usage.

With the aid of instant nonlinear finite element method, a numerical simulation to dynamic buckling of the implosion liner driven by magnetic pressure has been carried out. The principle of the method and the results of simulation has been introduced and discussed. The comparison of simulation results with experimental ones indicated that the simulation method established by this paper are validated and can be used as a useful tool for the study of liner implosion buckling.

The elastic constants of bulk lithium with hexagonal close-packed (hcp) structure under high pressures have been calculated, by using Density Functional Theory and the relationship between stress and strain. From our results, C₁₂ and C₁₃ increase linearly with pressures, but pressure effects on C₄₄ and C₆₆ are not obvious. At each pressure, C₃₃ is bigger than C₁₁, indicating rigidity of lithium in z direction is harder than that in x, y direction. It has been found that C₁₁ and C₃₃ have step-like changes in the phase transition zone. The results of the compressional wave anisotropy (Δp) show that Δp is equal to 1 at zero pressure and still near 1 under high pressure, meaning hcp lithium have the compressional elastic isotropy. The shear wave anisotropy (Δs₁, Δs₂) are away from 1 and this tendency increases with the increasing of pressure, showing the shear elastic anisotropy. Pressure effects on the Cauchy relations and the normalized elastic constants of hcp lithium are also discussed in this paper.

The rock breaking mechanism by water jets impact has not been clearly recognized as yet for complicated process of rock damage. The test of cutting rocks with submerged high-pressure water jets impact by a numerical controlling jet cutting machine are conducted. Then, the test for the pattern of failure surface of cutting slots and dilapidated slices are performed with scanning electron microscope (SEM) to study micro failure mechanism of rocks with water jets impinging. The result shows two types of rectangle shape and shallow funnel shape craters in the rock matrixes. The analysis shows that the micro-mechanism of rock failure due to water jets impingement is a brittle fracture in the condition of tensile and shearing stress.

The driving abilities of strong detonation in two stages explosive/flyer system have been studied by both analysis and experiments. Under certain condition, the system's geometric parameters are optimized in order to drive final flyer to high speed. The abilities of strongly detonating explosive slab in driving metallic flyers to high speed are shown in our calculation model. Calculated results agree with experimental results. The performances of strong detonation are illustrated. And numerical calculation shows that converging detonation can be an effective method to accelerate a flyer up to high speed.

Based on the Debye mode, electron gas model, and Grüneisen equation of sate, new formula were deduced which describe the individual contributions of lattice vibration and hot electron to shock temperature, shock pressure and compression volume of porous metals. It is found that the contribution of lattice vibration to shock compression volume accord with W-J equation; meanwhile, the contribution of hot electron to shock compression volume also can be calculated by the improved equation. In this paper, we especially discussed the reliability and the physical meaning of the new equations.

DFT-LDA method has been performed on calculations for fcc structure solid agon. The equation of state and adiabatic elastic properties of solid argon has been calculated up to 82 GPa. The results are in good agreement with the experimental data. The calculation indicates that the elastic properties and p-V relationship of solid argon can be obtained with local density approximation. If the parameters for calculation can be chosen properly, the elastic properties and p-V relationship of solid argon can be calculated exactly and save large of resource of computation at the same time.