The Raman spectra of gypsum in the pressure range of 200~1 100 MPa is studied at ambient temperature, and the dissolvability and phase transition of gypsum are observed. It shows that gypsum is stable at the pressure less than 407 MPa; and then gypsum begins to dissolve with the increasing pressure. Gypsum stops dissolving and phase transition happens (gypsum-bassanite) to some degree. After phase transition, bassanite disappears with the rising pressure. It implies that geological disasters will happen because of dissolvability and phase transition of minerals in the inner of earth.

The microstructures of hypoeutectic and hyper-eutectic Al-Cu and Al-Si alloys solidified at high pressure (5 GPa) were investigated. The results showed that high pressure had an evident influence on the morphologies and the dimensions of the solidified microstructures. This influence is directly related to the temperature interval of the liquid-solid region in the phase diagram. When the temperature interval is increased by pressure, the solidified microstructure will be coarsened. When the temperature interval is decreased by pressure, the solidified microstructure will be refined. Moreover, a new method is proposed to easily evaluate the sizes of the cellular and the dendritic microstructures.

The enzymolysis rates of cellulase on dietary fiber under dynamic instantaneous high pressure (IHP) were studied. Utilizing the Microfluidizer machinery as the carrier of Instantaneous High Pressure treatment to deal with dietary fiber from bean dregs, we got dietary fiber of different granularities and densities under different pressures and different times under the same pressure. The corresponding enzymolysis rates of cellulase on dietary fiber were different. The hydrolysates of cellulase on dietary fiber were of some reducing sugars, such as cellobiose and glucose. The enzymolysis rates could be estimated by measuring the contents of the reducing sugars in the dietary fiber of different granularities and densities. The results indicated that with the increase of the pressure in the range of 40~90 MPa, the granularities of the materials reduced drastically, the densities of the materials and the enzymolysis rates increased. And the granularity of the materials was in minimum of 202.4 nm; when the pressure went on increasing, the granularities of the materials tended to increase because of the occurrence of expanding in the system, but the densities started to decrease and the enzymolysis rates kept increasing. The density of the materials was in minimum of 1.027 g/mL, the contents of the reducing sugars after enzyme hydrolysis was maximal at this time. When the pressure was higher than 140 MPa, the granularities and density of the materials increased, the enzymolysis rates decreased. It could be due to the reuniting of particles in the system. When the materials were treated separately with instantaneous high pressure between 90 MPa and 140 MPa for several times, the granularities of the materials increased with the increase of dealing times, the density decreased first and then increased, and the enzymolysis rates decreased.

Shock heating can cause temperature rise prior to the porous liner collapse process because of its porous nature, which is possible to increase the jet temperature and enhance the jet ductility. The temperature rise calculation method was presented, and the porous effect on the jet behavior was studied with the pulse X-ray photograph. It was shown that the jet ductility increased with the initial porosity within some value, and the jet diameter became smaller with increasing initial porosity.

By combining pseudopotential plane-wave method at 0 K with Car-Parrinello molecular dynamics at finite temperature, the behavior and aggregation of helium in niobium are simulated under different pressures. The result shows that the closed-shell helium atom plays a role of rigid-ball such that to destroy local metallic bonds of niobium and push away the near free electrons. Under ambient pressure and room temperature, locally high concentrated helium atoms immigrate towards the vacancy site, resulting in helium bubbles. The same helium density of He will dislocate Nb atom, forming an interstitial-vacancy pair for the helium bubble formation. Under high pressures up to 40 GPa, no bubble is observed in perfect Nb host lattice due to the failure of interstitial-vacancy formation.

To figure out the effect of electrode resistivity on the in-situ resistivity measurement with four-point probe method in a diamond anvil cell (DAC), the authors simulated the distribution of the steady electric field in the sample with finite element analysis (FEA). It reveals that the electrode resistivity smaller than the sample resistivity too much would result in a large measurement error, and therefore indicates that reducing the resistivity difference between the electrode and sample can improve the measurement accuracy.

We have investigated the electrical properties of rock sample from Yinshan orogenic zone by in situ complex impedance spectroscopy using a multianvil apparatus. The electrical conductivity was measured at pressure of 1 GPa and temperature from 250 ℃ to 1 100 ℃ at frequencies from 0.1 Hz to 1 MHz. The data of resistance were obtained by using an equivalent circuit fitting technique. From these measurements we determined the electrical conductivity of the Archean metamorphic biotite- and plagioclase-bearing gneiss. The experimental results indicate that (1) each spectrum consists of an almost semicircular high-frequency arc Ⅰand a depressed high-frequency arc Ⅱ. The impedance spectrum Ⅰ is dominated by grain-interior response; the impedance spectrum Ⅱ is dominated by the sample-electrode interface impedance. (2) Electrical conductivity displays Arrhenian behavior respectively over investigated temperature range from 250 ℃ to 700 ℃ and from 750 ℃ to 1 100 ℃. However, it rapidly increases from 700 ℃ to 750 ℃. This jump is due to dehydration-melting of biotite within sample based on the comparative analysis of SEM photoes and electron probe data for pre-run and post-run samples. (3) Over higher temperature range (750~1 100 ℃), sodium is the dominating charge carrier in partially molten samples. (4) The activation energy of biotite- and plagioclase-bearing gneiss is 0.53 eV over range of temperature from 250 ℃ to 700 ℃. However, the activation energy of partially molten sample is 1.41 eV over range of temperature from 750 ℃ to 1 100 ℃. This change of activation energy has relations with sodium content and mobility in melt. It is possibly due to the change of structure between mineral and melt within samples.

Numerical simulation of the penetration of tungsten alloy long rod into semi-infinite armor steel targets is performed with ALE method and Steinberg constitutive model coupled in ANSYS/LS-DYNA finite element code. The configurations of four different phases in the penetration process and the changes of relevant physical parameters with time are given. The distribution of pressure, particle velocity and the material flow characteristics of both the penetrator and the targets are analyzed. It is revealed that the numerically predicted depth of penetration is in good agreement with available experimental results and that the behavior of materials adjacent to the interface of penetrator and targets is controlled mainly by the hydrostatic pressure.

The equation of states, elastic constants and other mechanical properties of transition-metal osmium under high-pressure are studied by the first-principles plane-wave pseudopotential calculations based on the density functional theory (DFT). The calculated results indicate that osmium has high bulk modulus B₀ (423.9 GPa) and large elastic constants C₁₁ (771.3 GPa) and C₃₃ (852.0 GPa) comparable to diamond (B₀=452.8 GPa, C₁₁=C₃₃=1 082.9 GPa), so it is an ultralow-compressible material. However, its elastic constant C₄₄ (269.8 GPa) and shear modulus G (276.8 GPa), which indirectly measure hardness, are half of those of diamond (C₄₄=586.9 GPa, G=537.5 GPa). Because of its pure metallic bonds, it may not be superhard material. The microscopic mechanism of high bulk modulus and low hardness can be understood from the analysis for electronic structures, and it helps to design and synthesize new superhard material.

In order to study the pressure-induced changes of biological and physiochemical properties in fungi, Aspergillus Oryzae was treated with high pressure at 0.1~400 MPa for 20 min, and their viability and modality, as well as the activity of protease and amylase were determined. The result showed that high pressure induced obvious changes in the viability and modality of Aspergillus Oryzae. The activities of protease and amylase in Aspergillus Oryzae showed a specific regular pattern upon high pressure treatment. In the pressure range of 0.1~200 MPa, the protease activities decreased, but enhanced gradually in the range of 200~400 MPa. The protease activity was larger than control strain after treatment fungi with 300 MPa or higher, and reached the maximal at 400 MPa. The activity of amylase also decreased with pressure in the range of 0.1~100 MPa and gradually enhanced in the range of 100~200 MPa, and subsequently decreased again at the range of 200~400 MPa. The activity of amylase is highest in the treatment with 200 MPa, and same as control strain at 400 MPa. A fine mutant strain of fungi, HP300a, was obtained after treatment with 300 MPa. HP300a has a series of excellent characteristic: quick growth, more spores, higher activity of protease, and is rarely polluted by other strains. In addition, several indexes of soy sauce brewaged by HP300a were much better than that by control strains.