In order to study the relation of powder liner material density and performance of the shaped charge jet, the curves of shaped jet velocity, jet particle momentum and jet particle kinetic energy with respect to the liner density were calculated under the same charge conditions, according to the Birkhoff's steady theory and Gurney's formula of crushed speed. In the same charge structure, the jet velocity and penetration power of two kinds of powder liner were tested, whose mass ratios of W to Cu were 0.5∶0.5 and 0.4∶0.6 respectively. It is found that the experimental results are well in agreement with the calculation results. Therefore, it is considered that the calculated curves have certain reference values, and the penetration power can be increased effectively by improving the density of powder liner.

The experiments of small scale projectile obliquely penetrating a semi-infinite concrete target with a velocity from 980 to 1 870 m/s are performed by a two-stage light gas gun. The ballistic trajectory and characteristic parameters are tested and painted. The results show that the trajectory deflection of the penetrator obliquely penetrating a semi-infinite concrete target with high velocity is more obvious than that with intermediate and low velocities, and presents a shape of “J”. The penetration process can be divided into four phases according to the penetration mechanism. In addition, it is found that the terminal gesture of the projectile changes greatly, and the deflection angle at endpoint can reach up to 130°.

Field explosion experiments were carried out to investigate the contact explosion damage effects of large diameter X70 steel oil-gas pipes. The contact explosion damage characteristics of pipes with different pipe wall thickness under various charge were analyzed. The experimental results show that the local damage of the pipe wall facing explosion is predominant and there is a petal-shaped crevasse. In addition, the fragments with abundant kinetic energy are formed. The dent or perforation phenomenon will occur after the opposite pipe wall is impacted by the fragment. By means of an explicit nonlinear dynamic finite element computer code LS-DYNA, the nonlinear dynamic response process of the steel pipe under contact explosion loading was numerically simulated with Lagrangian-Eulerian coupling method. The damage process of the pipe wall facing explosion and the after-effects of opposite pipe wall due to the impact of fragment were described. The numerical simulation results are in good agreement with experimental data. The results can provide important reference for the blast-resistant properties analysis and safety assessment of oil-gas pipes.

In order to solve the difficult problem about the security of warhead in the penetration process, the relationship between damage and hot-spot formation in the charge has been researched. Based on crack friction under mechanical impact, a thermo-viscoelasticity constitutive model for explosive materials coupling the crack damage and hot spot formation is presented to analyze the formation of hot spot in warhead charge during penetration. The influence factors of hot-spot formation under different penetration conditions are discussed and compared. The numerical simulation method provided can be used to design and evaluate the security of loaded projectiles under impact.

The capacity for work of insensitive high explosive JB-9014 was studied and compared with high explosive JOB-9003, by improved standard cylinder test, in which combined streak photography and laser interference technique. The results indicate that the capacity for work of JB-9014 is less than that of JOB-9003 evidently. After the expanding velocity is relatively stable, the capacity for work of JB-9014 is about 68.56% of JOB-9003 at the same expanding time and about 69.39% at the same radial displacement. The ratio of capacity for work of JB-9014 and JOB-9003 increases with expanding time and radial displacement gradually, which is consistent with the distinct performance of insensitive high explosive.

In order to obtain information about the influence of experimental conditions on the results of underwater explosion, the relationships between measure position, explosion depth and explosion parameters, which contain shock overpressure, shock wave energy per unit mass, bubble pulsation period and bubble energy per mass, were studied by experiments. The results show that the peak pressure of shock wave and shock wave energy per unit mass decrease with the increment of distance between measuring position and explosive sample, the bubble pulsation period increases and bubble energy per mass decreases with the increasing of the explosion depth. The distance between the measuring position and explosion position are at least greater than twice of the bubble radius, and the explosion depth should be 1/3 to 3/4 of the tank depth.

In order to study the shell fragmentation and the early motion of extinguishing medium after explosion in the cold shock-wave extinguishing system, the pressure on the inner wall of the cold shock-wave extinguishing bomb must be firstly understood. The change of pressure has been studied by dimensional analysis, mechanical structure, and explosion experiments. It is found that the pressure is related to the charge weight and bomb diameter, and the pressure waveform measured at the inner wall is rectangular. When the bomb diameter is 104 mm, the duration of high pressure is above 100 μs; when the bomb diameter is 220 mm, the duration of high pressure is above 200 μs. In addition, the specific central explosive charge of powder is more than that of water under the same dimension of the cold shock-wave extinguishing bomb to reach better effect of the shell crushing. Owing to the higher energy dissipation during compression, the finer powder and pre-compression powder are suggested as extinguishing medium in powder cold shock-wave extinguishing system.

In order to have an insight into the propagation of non-ideal detonation wave confined by inert medium, the shock polar method relating the pressure/streamline-deflection matching condition at the explosive/inert medium interface was adopted. The detonation front shape and the pressure distribution were calculated by this method combined with detonation shock dynamics (DSD) method and the program describing detonation acceleration. Comparison between experimental data and numerical simulation results shows that although a detailed description for interaction between the detonation wave and the inert medium needs full hydrodynamic simulation in the complete flow field, a relatively simple shock polar analysis can also provide a good prediction of the interaction effect, which is consistent with the argument from Aslam et al. of United States of America.

As a new non-thermal technology, high pressure processing destroys vegetative microorganisms and inactivates enzymes, whereas fresh flavour, colour, mineral balance and vitamins mostly persist. In addition, high pressure processing has been investigated to decrease the allergenicity of food protein. Combination with other treatments (such as thermal) and agents (such as enzyme), allergenicity can be almost eliminated. This paper reviews literature on the recent advances in eliminating or decreasing the allergenicity of food protein by high pressure treatment. The mechanisms of high pressure treatment induced alteration of allergenicity are also discussed.

The effects of high hydrostatic pressure (HHP) treatment at 100-500 MPa for 10-30 min on the solubility and molecular structure characteristics of thermal denatured rice protein dissolved in solvent A (water solution, pH 8.0) and solvent B (containing 6 mol/L urea and 1% mercaptoethanol, pH 8.0) were researched. The results showed that the solubility of rice protein in solvent B was notably improved after HHP treatment, especially at 100 MPa for 20 min, which was from 6.89% at 0.1 MPa up to 18.13%, while in solvent A, it was from 4.37% to 9.60% at the same pressure condition. SDS-PAGE analysis showed that the subunit composition of soluble protein treated under HHP in solvent A had few differences from that of untreated. The similar phenomena could be seen in insoluble protein. However in solvent B, the relative contents of the subunits in soluble changed obviously. The observation of SEM (Scanning Electron Microscope) showed that the surface structure and aggregation state of rice protein could be changed by HHP treatment.