The effects of combined high pressure (0.1~600 MPa) and temperature (20~60 ℃) treatment for 20 min on beef protease activities were studied. The results showed that the protease activities decreased with increasing pressure up to 400 MPa at room temperature, after which there was no significant change of them. The content of free amino acid increased significantly at 200 MPa and then the increased speed decreased with the pressure increasing.400 MPa or higher pressure treatment at room temperature resulted in the increase of tryptic digestibility of protein in beef extract. There was no significant effect on protease activities and free amino acid content in beef after pressurized at 200 MPa, 40 ℃, but the protease was almost completely inactivated at pH 7.5 and free amino acid content reduced rapidly after treated at 600 MPa, 40 ℃. Part of protease activities survived in beef muscle when heated at 60 ℃. They did not change significantly when treated at 200 MPa, 60 ℃, but the free amino acid content increased obviously. Treatment of 600 MPa at 60 ℃ resulted in the inactivation of almost all the proteases and the free amino acid content also decreased markedly. The similar changes of tryptic digestibility of protein in beef extract were found when pressure applied at 40~60 ℃. 200 MPa treatment did not cause significant changes and 600 MPa treatment induced the tryptic digestibility of protein marked increase. These results suggested that high pressure treatment combined with heating could regulate proteases activities of beef and improve its quality.

HL-10 explosive is an aluminized explosive based on RDX. In order to investigate the safety characteristics of HL-10 for bullet impact test, 12.7 mm bullet was used to impact HL-10 charge. Experimental results show that there is no significant reaction or burning resulted from these bullet impact tests, so the impact sensitive of HL-10 for bullet impact test is defined as the first grade. The calculation modes and methods of bullet impact tests were established. The three-dimensional numerical simulations of the bullet impact tests were conducted. Good agreement was found between the calculated results and the experimental results. In addition, the responses of HL-10 to different bullet impact velocities were analyzed. The calculated results can provide a theoretical basis for the analysis of explosives safety evaluation. To further verify the calculation model and method, the bullet impact test calculation for America PBX-9404 explosive was conducted. The results show that, PBX-9404 explosives would be detonated at 850 m/s impact velocity for the same calculation mode, which are consistent with Neff and others experimental results.

The growth process of synthetic diamond single crystals under high-pressure and high-temperature (HPHT) was tested with acoustic emission technique. Associated with the fracture morphologies of the synthetic mass, the main acoustic emission dynamic parameters corresponding to growth process of diamond single crystals were analyzed. The results indicate that the energy, count, amplitude and rise time of recorded acoustic emission signals can be objective reflection of the dynamic growth process of diamond single crystals under HPHT. The research provides the important experimental basis for studying the in-situ reaction mechanics of synthetic diamond single crystals under HPHT by using acoustic emission testing.

Based on the homogenous fluid reaction N-S equations, the k-ε turbulent model and the EBU combustion model, the propagation of detonation wave in a sudden area change tube and the influences on the thrust performance of the main tube with different nozzles were investigated. Our results show that, a new detonation can be initiated promptly when the detonation wave of the pre-detonator injects into the main tube. In addition, with the mount of nozzle, the average thrust of single detonation varies. The head-end thrust increases with the raise of the contracting angle of nozzle, and decreases with the raise of its diverging angle. But the average total thrust increases with the diverging angle, and decreases with the raise of converging angle. There also exists an optimal diverging angle which can generate maximum average total thrust.

In order to accommodate to the needs of micro-explosive train in MEMS fuze, this paper carried out a specific study about the influence of charge height on the output detonation pressure in micro-detonator. The charge diameter is 0.9 mm, total height is 3 mm. The charge ratio of primary explosive and high explosive was to be changed. The output detonation pressure was measured by manganin piezoresistance method. In the micro-detonator, the critical height of primary explosive PbN₆ is 0.36 mm. When the primary explosive PbN₆ height is 1.65 mm, the micro-detonator has the maximal output detonation pressure 10.3 GPa. When the primary explosive PbN₆ height is less than or more than 1.65 mm, the high explosive HMX height is less than or more than 1.35 mm, and the output detonation pressure of the micro-detonator is reduced. The range of the primary explosive PbN₆ and the high explosive HMX is 0.69~2.26.

The shock pressure at the interface between booster charge and PMMA gap was calculated by graphing method. The AUTODYN was used to simulate the attenuation process of the shock wave in the PMMA gap. The output shock pressures, which were produced by the substituted booster charge of the UN gap test, were measured in the PMMA gap at different positions by manganin gauges. The shock velocity, particle velocity and density after the shock front were calculated. The results showed that the measured data, theoretical arithmetic and numerical simulation are consistent, and the attenuation regularity of shock pressure in PMMA is extracted from the test results. AUTODYN 6.1 software is capable of predicting the attenuation characteristic of shock wave in PMMA gap.

The short duration of high temperature and high pressure during the detonation process made the TiO₂ nanoparticles not have enough time to grow into large and fine crystallites and only generate a large number of spherical-like nanoparticles. The rapid interactions between these formed TiO₂ nanoparticles (such as collision, friction, extrusion, infiltration and adhesion) could easily form agglomerate structures in the humid detonation gas environment. The agglomerate structures and dispersion morphologies of the TiO₂ nanoparticles prepared by detonation method using titanium titanyl sulfate as TiO₂ source were studied. In order to reveal the influence of heat treatment on the agglomeration properties of the TiO₂ nanoparticles, the agglomerate structures of the TiO₂ nanoparticles via heat treatment at 500 ℃ for 1 h were also analyzed. Research showed that the soft and hard agglomerates of the TiO₂ nanoparticles were formed and that the agglomerate structures of the TiO₂ nanoparticles after heat treatment could be improved to some extent. The influences of nanoparticle characteristics, detonation characteristics and detonation gas environment on the formation of the agglomerate structures of TiO₂ nanoparticles were also discussed.

The defining of effective acting time for pyrotechnic composition combustion underwater was put forward. The main problems of current methods for testing and processing the acoustic radiation characteristics of pyrotechnic composition combustion underwater and explosion underwater were analyzed. And then, based on Pulse Labshop software platform and experimental results, the effective acting time for pyrotechnic composition combustion underwater was obtained, with graphic slicing technique. This new method can be used to assess the effective acting time of pyrotechnic composition combustion underwater and explosion underwater sound source, and so on. It also provides a reference for the engineering application and performance evaluation.

The electronic structure and optical properties of pure and Mn-doped or Fe-doped zinc blende ZnS were calculated by first-principles ultra-soft pseudopotential approach of the plane wave based upon the density functional theory, and the band structure, density of states and optical absorption properties were studied. The calculated results show that the density of states near Fermi energy level is derived from Mn 3d and Fe 3d states. Moreover, the optical absorption spectrum shows an obvious red shift, also extends to lower energy side and generates a new peak of optical absorption at the low-energy side after doping with Mn and Fe.

It is very important and instructive for us to further and accurately investigate the interaction between constitutes of explosive and formation mechanism of hot spots in explosive initiation, with the constitutive relation and equation of states in wide pressure zone. Compared with shock compression, magnetically driven quasi-isentropic compression (shockless compression) is a more effective method to research the dynamic behavior of un-reacted explosives in wide pressure zone. Based on the working principle of electro-magnetic force produced by large current, the shockless compression technique driven by magnetic force was first realized in domestic. By optimizing the loading electrodes and the parameters of explosive samples, and controlling the installation technology, a pressure of 5 GPa was realized in magnetically driven quasi-isentropic compression experiments. By means of the technique of laser displacement interferometer and the Lagrange data processing method, the particle velocities of the interface between JO-9159 explosive and LiF windows were measured, and from which the experimental isentropes of JO-9159 explosive were obtained. Compared with the results from references, the experimental isentrope of JO-9159 explosive is consistent with that of PBX9501 explosive.