To synthesize a carbon nitride with high density existing by theoretical prediction, a series of shock recovery experiments up to ≈50 GPa were carried out on two nitrogen-rich materials of a C-N-O amorphous precursor and dicyandiamide. The powder X-ray diffractions (XRD) of recovered samples show that the carbon nitride composite phases are formed consisting of β-C₃N₄ and a new crystalline phase. The new phase is indexed as a monoclinic cell with a=0.981 nm, b=0.723 nm, c=0.561 nm, β=95.2° and V_cell=0.396 6 nm³. We considered that this new phase is formed to survive as metastable species by extremely high quenching rate (≈10⁹ K/s) after transient shock-induced reaction of these organic precursors and so shock compression may provide a novel synthesis route for various carbon nitride phases from appropriate rich-nitrogen organic materials.

This paper measures the Raman peak displacements of the four vibration modes of S—O bonding and the hydroxyl-stretching vibration modes in the gypsum at high pressures using diamond anvil cell. The experimental results show that at the temperature of 25 ℃ and the pressure of 100~800 MPa the Raman peak positions of the S—O bonding in the gysum shift to high wave numbers with the increase of the system pressure, while the Raman peak positions of hydroxyl-stretching vibrations shift to low wave numbers with the increase of the system pressure. The relations between the Raman peak positions and system pressure were obtained, and the two dν/dp values of hydroxyl-stretching vibrations show a great difference because of different intensity of the hydrogen bonding.

BN is synthesized by benzene thermal method using (C₂H₅)₂O·BF₃ and Li₃N as reactants and its phase transition mechanism is studied. Not only hBN and cBN are found in the products testified by XRD and FTIR, but also oBN, atmosphere form Li₃BN₂(O) and high pressure form Li₃BN₂(T) are discovered. The differences of cBN catalytic mechanism between high pressure and high temperature method and benzene thermal synthesis method are analyzed. Furthermore, the catalytic mechanism of Li₃BN₂ to synthesize BN using Li₃N and (C₂H₅)₂O·BF₃ as reactants is discussed. At the same time, it stands out the atmosphere form Li₃BN₂(O) and the high pressure form Li₃BN₂(T) can catalyze the synthesis of cBN and oBN, respectively.

The spall properties of AF1410 steel are studied with the loading by gas gun. The Hugoniot relationship, plastic strain rate, spall strength, spall thickness and other dynamic parameters are obtained from experimental measurement. By the fracture analysis and metallographic analysis, the spall fracture mechanism at different strain rate is discussed.

The physical and computational models of explosive damage effect of obstacles in water are proposed. The conservation equations, the dynamic elastic-plastic constitutive relation and damaging criterion of concrete are established, together with the yielding criterion subjected to large strains, high strain rates and high pressures. Meanwhile, based on the multi-material Eulerian algorithm, the NM-MMIC code, which is a general 2D multi-material elastic-plastic hydrodynamics code with C⁺⁺ language, is applied to simulate the damaging effects of obstacles in water by explosion with different charges and at different positions. The whole process of underwater explosion are visualized by VISC2D code. The pressure variation of the side of the obstacle facing to the explosive are demonstrated quantitatively. The optimum damage charge is obtained. The damaging degree, and the damage laws of the obstacle in water are evaluated. These results are valuable in designing and estimating ammunitions against obstacles in water.

Relation between mass density of explosive detonation products and time is studied under three kinds of confinement conditions, i.e., no confinement, weak confinement, and rigid confinement by coupling of BKW code, JWL code and LS-DYNA program, respectively. Associated with HOM equation of state, explosion products temperature decaying with time is inferred, and theoretical method is proposed to calculate explosion products temperature of warhead. Results imply that temperature and its decaying rate in explosion products region are non-uniform. Confinement condition plays an important role in controlling of explosion products mass density and its temperature. Rigid confinement could postpone the decaying of the explosion products density and temperature, but the decaying time does not scale up in spite of the doubling of the shell thickness.

From the definition of isothermal bulk modulus and an assumption of its relationship with the pressure, an isothermal three-parameter equation of state has been proposed, which is found to be applicable at high pressure. The proposed equation of state has been used to compute the pressure-volume behavior of NaCl crystal in the pressure range 0~30 GPa and CsCl crystal in the pressure range 0~40 GPa. The isothermal bulk modulus in the pressure range 0~30 GPa of NaCl crystal were also calculated. The results are in very good agreement with the experimental data. The pressure dependence of the isothermal bulk modulus B_T and its first- and second-order pressure derivative are discussed, and the bulk modulus increases continuously with the increasing pressure and has a finite value as p→∞.

The optical properties and electrical structure of V in ZnS supercell have been computed by means of plane wave pseudo-potential method (PWP) with generalized gradient approximation (GGA). The calculated optical property is in consist with the values calculated by the theory of crystal field and with the experiment results. By importing impurity, the energy level has a shift about -2.5 eV. The Mulliken charge of V is 0.28, which is smaller than every kind of Zn, and the covalency of bond S—V is strongest than other bonds, and the length is the shortest.

To investigate the effect of ferroelectric power supply initiating metal bridge foil, the electrical responses of the shock-loaded PZT95/5 ferroelectric with copper bridge foil load were numerically calculated. The non-linear resistance model was used for the metal bridge foil. The voltage, current, and resistance of metal bridge foil under different number of ferroelectric blocks arranged in parallel were calculated. By the results of calculated voltages and resistances of copper bridge foil, the number of parallel ferroelectric blocks to make copper bridge exploding was obtained. The calculation and results provide a theoretical basis to design the ferroelectric power supply initiating metal bridge foil.

Dynamic cylindrical cavity expansion model and its application to penetration problems were studied. Both incompressible and compressible bilinear strain-hardening material models were considered. First, solutions for dynamic cylindrical cavity expansion (DCCE) are obtained in terms of the velocity of plastic wave front, radial stress distribution and stress on the cavity surface. The influence of material properties such as compressibility, elastic-plastic constitutive equations and plastic modulus is discussed. Based on the DCCE models, penetration equations are then constructed. Comparison with experimental penetration data shows reasonable agreement between theory and experiment. It also shows that material properties such as plastic modulus have considerable effects on the dynamics cavity expansion and its resistance to penetration.