JH-2 constitutive model parameters of YB-AD90 ceramic were derived from experiments and literatures. The penetration depths and the dynamic penetration processes of rod projectiles into YB-AD90 ceramic targets were numerically simulated using Autodyn-2D. The results indicate that the simulation method and parameters of JH-2 model are acceptable. Some important features in the penetrating processes such as the shape change of the projectile head, the material fragmentation, and the channel-collapse are simulated and discussed. The simulation results are consistent with experimental results.

The underwater blast shock wave in absorber structure was numerically simulated by ANSYS/LS-DYNA. The results showed that the shock waves decay in the absorption foam layer due to the effect of the constitutive of the foam material, and the peak pressure of the stress wave in the multi-layer structure containing foam concrete has a greater decline than that with foam aluminum, but this has little impact on shock wave transmission. The shock peak pressure in the protective structure with absorbed layer is only 14% of that without an absorbed layer. Further analysis showed that the total energy of foam concrete is higher than that of foam aluminum, indicating foam concrete is superior to foamed aluminum as the absorbed layer in protective structure.

Based on the reduced methane oxidized element reaction model, CFD software and ISAT algorithm were used to establish a two-dimensional turbulent explosion model for premixed CH₄-O₂-N₂ mixture. Computational results show that the process of ignition, combustion and explosion of the premixed CH₄-O₂-N₂ mixture can be simulated well by the model. The influence of the initial temperature of the high temperature core and the component of mixture on combustion and explosion were considered in the numerical computations. Simulation results indicate that the initial temperature of the high temperature core has an important effect on the ignition delay time and the early combustion phase of the premixed CH₄-O₂-N₂ mixture, but it hardly affects the CJ deflagration phase. The reaction activity of the premixed mixture is reduced by adding N₂, which results in the increase of ignition delay time and the decrease of deflagration reaction speed, explosion overpressure and free radical concentration. The computational results of explosion overpressure are in good agreement with experimental results on the same conditions.

The high hydrostatic pressure treatment on sea cucumber has many advantages over traditional processes and it has a promising future. Effects of processing parameters on holothurians autoenzyme activity were investigated within the range of the parameters: the processing pressure of 0.1~550 MPa, the pressure-keeping time of 0~30 min, the processing temperature of 24~62 ℃. Under the room temperature and pressure-keeping time of 20 min, the autoenzyme activity decreased to 88.25% at 200 MPa, increased to 106.77% at 250 MPa, and reached the lowest level of 29.81% at 550 MPa. The holothurians autoenzyme activity increased first and then decreased with the increasing of pressure-keeping time and temperature. The effect of pressure-keeping mode on holothurians autoenzyme activity was not significant. The BP artificial neural network was used to predict the effects of high pressure on holothurians autoenzyme. Compared with the experimental results, the average relative error of predicted results was 0.9%. The experimental results show that the holothurians autoenzyme can be activated and inactivated at certain pressure, pressure-keeping time and temperature. The study provides some valuable information for optimizing the high hydrostatic pressure treatment of holothurians autoenzyme inactivation.

Reactive material is a kind of novel impact-initiated energetic material. Understanding the mechanical property of reactive material is an important premise for its application. The tensile and impact properties of polytetrafluorethylene (PTFE)/Al series reactive materials were investigated experimentally using a universal materials testing machine and an improved pendulum impact tester at room temperature. Experimental results show that with the increasing of Al content in PTFE/Al, the tensile strength increases firstly and then decreases. When the Al content is 6%, the tensile strength achieves 36.1 MPa, which is in good agreement with the calculated result. The damage behavior of PTFE/Al is in three steps, including deformation, ductile crack and reaction. With the increasing of Al content, the toughness of PTFE/Al increases firstly, then decreases subsequently. It reaches the maximum of 72.06 J/cm² when Al content is 40%. At the same condition, the difficulty to reaction is also enhanced and the self-sustaining reaction is suppressed.

Domino effect is a well-known cause of major accidents in the chemical process industries, resulting in overall consequences which are more severe than those of the primary event. Fragment projection is one of the major escalation vectors to cause domino effect. The present work took a spherical tank with boiling liquid expanding vapor explosion (BLEVE) as an example. The probability distribution density of uncertain parameters in the generation and flight of fragments were determined by the data from literatures, and simulated by Monte-Carlo method. Then the projectile distances of fragments were calculated. In this way, the impact probabilities of fragments on objective vessels were attained. The impact probabilities of fragments on the different objective vessels have great gaps. However, the impact probabilities of fragments produced by vessels with different filling levels on the same object are almost same. This method is of great significance for the risk assessment and control of fragments from explosion of spherical tank. It can be used to provide guidance and reference for determining safety distance to prevent domino effect of fragments between storage tanks.

A novel laser screen detection system was developed to measure the projectile's flight velocity in two-stage light gas-gun. By means of complex anti-jamming methods such as slit aperture limiting external stray light, narrow band spectrum filtering and low frequency notch filtering, the problem of detecting and catching the instantaneous weak disturbance signals from a bright background source was solved, and a high signal-noise ratio was achieved. A typical experiment of a spherical metal projectile with a diameter of 4 mm was performed in a two-stage light gas-gun. The results showed that the inconsistency in projectile's speed between this device and the coil for real-time monitoring is less than 2%, implying this device can meet the requirement of mm-size projectile's velocity measurement in two-stage light gas-gun.

Structural stability of ZnSe nanoribbons was analyzed by means of high-pressure in situ angular dispersive X-ray diffraction (ADXD). The pressure-induced structural transition from the Zinc blende (ZB) to a rocksalt (RS) phase occurs at about 12.6 GPa, and at the transition point the relative volume reduction is close to 13%. By fitting the relative volume-pressure relation to the Birch-Murnaghan equation of states, the bulk modulus B₀ for the ZB and RS phases were determined. The values of B₀ are 56 GPa (B′₀=4) and 116 GPa (B′₀=4) for the former and the latter, respectively. According to the measured high-pressure Raman scattering spectra, the TO phonon modes split into two peaks at about 5.5 GPa, and the LO peak gradually disappears above 12.8 GPa due to the semiconductor-metal transition. Using the value of the bulk modulus obtained from the ADXD experiments, the corresponding mode Grüneisen parameters are obtained for the ZB phase.

Field emission scanning electron microscope (FESEM) has been used to investigate the fine structure of Fe-based metal film interface and its cross-section. It is shown that nanoscale pyramid cone shapes are found on the metal film interface (100), serrate steps are found on the metal film interface (111), and cystiform shapes with terrace structure are found on the cross-section near the catalyst. Other faults have brittleness fracture characteristic with nanoscale clusters are found on the fault surface. It is proposed that the different morphologies of the metal film have relations with catalyzing mechanism. The brittleness fracture characteristic of the cross-sectionon might be due to the carbide existence, and the nanoscale particles should be eutectic carbides.

Based on the principle of minimal energy and Stoner-Wohlfarth model, the effect of the tensile stress on the exchange bias for ferromagnetic/antiferromagnetic bilayers has been investigated. When the applied field is absent, according to the relation between the energy of the system and the orientation of ferromagnetic magnetization, the location of the intrinsic easy axes and intrinsic hard axes of the system have been obtained. It is found that the system will be in monostable state or bistable state, which is controlled by the competition between the uniaxial anisotropy and the exchange anisotropy of the system. Monostable state and bistable state of the system determine the angular dependence of exchange bias immediately. When the applied field is parallel to the intrinsic easy axes and intrinsic hard axes, by analyzing the magnetization process, we find that one of the switching field of the hysteresis loop shows a jump, while the other is kept constant, and consequently the exchange bias field and the coercivity will appear a step. Both the exchange bias field and the coercivity have a greater value at the point of step. The numerical calculations indicate that both the magnitude and the orientation of the tensile stress will significantly affect the exchange bias by making a transition between monostable state and bistable state in the system. This transition induces a significant change in angular dependence of the exchange bias. Our results demonstrate that tensile stress is a viable way to control and tune the exchange bias of the ferromagnetic/antiferromagnetic bilayers.