We performed shock wave experiments on a natural pyroxene with chemical composition close to (Mg_0.92, Fe_0.08)SiO₃ and initial density of 3.06 g/cm³ at pressures between 48 and 140 GPa, using impedance-match method and electrical probe technique. Considering McQueen et. al. data, it is obvious that (Mg_0.92, Fe_0.08)SiO₃ goes through three phase regions in the procedure of shock compression: Low-pressure phase region (LPR), mixed phase region (MPR), and high-pressure phase region (HPR), corresponding to the pressure 0~40 GPa, 40~67 GPa and 68~140 GPa, respectively. In low-pressure phase region, the relationship between shock wave velocity D and particle velocity u was expressed by McQueen et. al. data. Then in high-pressure phase region (at pressures between 68 to 140 GPa), it can be described linearly from our experiment data. The calculated D-u relationship for the assemblage of (Mg_0.92, Fe_0.08)O(Mw)+SiO₂(St) is significantly different from the experimental data, excluding the possibility of chemical decomposition of perovskite to oxides during the shock compression. The Grüneisen parameter γ can be obtained by fitting the experimental data. Using the third-order Birch-Murnaghan finite strain equation of state, the shock experimental data yield a zero-pressure bulk modulus K_0S=259.6(9) GPa and its pressure derivative K′_0S=4.20(5), with ρ₀=4.19 g/cm³. A comparison of the experimental Hugoniot densities of perovskite with the PREM density profile prefers a perovskite-dominant lower mantle model.

N-type PbTe compounds doped with Sb₂Te₃ have been prepared at high-pressure and high-temperature (HPHT). The thermoelectric properties of all the samples have been measured at room temperature. The Seebeck coefficients in absolute value and the electrical resistivities decrease with an increase of Sb₂Te₃ content dramatically first and then slowly. The thermal conductivity slight increases with an increase of the content of doping. The figure of merit, Z, increases first and then decreases and the maximum value reaches 8.7×10^-4 K^-1 which is much higher than that PbTe doped with PbI₂ prepared at normal pressure. This result indicates that enhanced thermoelectric properties of PbTe can be obtained by the HPHT method with suitable dopant.

Evolution of Nano-void (diameter d≈1.3 nm) in single crystal copper and associated plasticity deformation around the nano-void under impact loading are investigated by means of molecular dynamics (MD) simulation. The results of simulation reveal that in the tensile process there are three of all four {111} family planes to be activated to glide, dislocations are nucleated in the region near the void surface and then move outside on three {111} family planes as the void grows. The velocity of dislocation along 〈112〉 directions with the maximum resolve shear stress can exceed transverse sound velocity. The calculated dislocation damping constant is appropriately consistent with the experiment results. Due to the approximately symmetrical plastic deformation around the void, the shape of the void during growth process is almost spherical. The growth rate of the void radius is observed to be constant under constant shock strength, and the amplitude increases as well as the shock strength increases.

To analyze the characters of out current of different number ferroelectric ceramics, the tests of PZT95/5 ferroelectric ceramics in parallel connection loaded by the shock waves were carried out. The output currents of ferroelectric ceramics for the resistance loads were measured. A model calculating the output current of ferroelectric blocks in parallel connection was developed. The currents under different number of ferroelectric blocks were calculated numerically with this model. By comparing the calculated results and experimental results, the effects of the number of ferroelectric and shock wave on output of current were analyzed. The results indicated that if the planar shock waves load the ferroelectric blocks, the shape of the output current will be quadrate and the current will increase along with the number of the ferroelectric blocks increasing. The shape of shock waves and the sparse waves influence on the output current and the depolarization ratio.

A damage function model is implemented in 2D finite element code-DEFEL, with which the simulation of plate surface spallation testing is performed by using the material parameters of three type steel, HR-2, 2169 and 45. The effect of strain-hardening and Bauschinger are taken into account. The calculated free-surface velocity-time relation curves are consistent with the experimental results. The damage distribution and its development in the spalled layers are also given from the numerical results. The spall strength of materials from simulation is higher than that from acoustical approximation, but lower than theoretical spall strength. The analysis of the differences among them shows that the simulation is reasonable.

The detonation characteristics of fuel (PO, IPN, C₅~C₆, hexane, heptane, Decane)-air cloud were studied in shock tube. The critical initiation energy was measured by the up and down method and cell size by smoked metallic foil. The comparison of detonation characteristics among these fuels was also carried. Results demonstrate that the relationship of critical initiation energy and equivalence ratio shows an “U” shape curve, the minimal critical energy is obtained when equivalence ratio is slightly larger than 1. The conclusion is similar to the gaseous detonation. These experimental results help us deeply understanding the detonation nature of hydrocarbon-air mixtures.

A new kind of Ta-Nb alloy has been studied. By means of ultrasonic measurement, its sound velocities of longitudinal wave and transverse wave were obtained, and some of its static mechanical parameters were calculated. Through shock compression experiments with a two stage gas gun, its shock Hugoniot curve in pressure range from 60 GPa to 196 GPa was obtained. The result was in good agreement with the calculation by a mixture model. The mechanical characteristics of Ta-Nb alloy with two kinds of tungsten alloy have been compared, which shows the dynamic behavior of Ta-Nb alloy is better than that of tungsten alloy.

In order to investigate the effects of combined treatment of ultra high pressure (UHP) and enzyme inhibitors on the activities of peroxidase (POD) and pectin methyl esterase (PME) in litchi pulp, two kinds of enzyme inhibitor prescriptions were designed including group A (citric acid 5 g/L+L-ascorbic acid 2.5 g/L+calcium chloride 5 g/L) and group B (citric acid 10 g/L+L-ascorbic acid 5 g/L+calcium chloride 10 g/L). After being immersed in enzyme inhibitor solutions for 10 min, the pulp of litchi (Litchi chinensis Sonn cv. Huaizhi) was subjected to UHP treatment (100~400 MPa for 30 min at 10 ℃). The activities of POD and PME were detected by spectrophotometry. Results showed that separate treatment of group A or group B could lead to obvious passivation of POD and prominent activation of PME. Combined treatment of UHP and group A could not make the activities of POD and PME decrease. The influence of combined treatment of UHP and group B on POD and PME had relevance to pressure value, the POD activity lowered when the combined treatment of 100~300 MPa and group B was applied, and the PME activity raised obviously when the combined treatment of 200~400 MPa and group B was applied. So, combined treatment of UHP and enzyme inhibitors had certain synergistic effect for POD inactivation, and the synergistic inhibition effect would be more obvious with higher concentration of enzyme inhibitors; but combined treatment of UHP and enzyme inhibitors showed certain rivalry for PME inactivation.

We studied the effect of high pressure process (HPP) on exoproteinase of Bacillus subtilis by using Box-Behnken response surface methodology. Experimental results showed that HPP could inhibit activity of exoproteinase significantly. In the course of treatment, pressure and temperature were key factors to passivate enzyme, and their interaction was notable. A model of exoproteinase passivation was established by design expert software, which determination coefficient was 0.974 7 and adjusted determination coefficient was 0.942 1. Analysis of variance implied that the model was significant. Therefore, the model could be used to analyze and predict. Additionally, the experiment indicated that exoproteinase activity correlated with lethal rate significantly (R=0.933 0). The exoproteinase could be regarded as an index to evaluate effect of HPP on microorganism.

Aimed at idiographic structure of DAVIS gun, for accurately calculating acceleration of projectile in bore, this article emulationally calculated the launch of a DAVIS gun through classical interior ballistics, acquired the interior ballistic parameters-time curves and educed the acceleration-time curve of projectile according to bore pressure-acceleration relation. The calculated results accorded with the experimental data.