Concrete is a widely used composite. The study of dynamic performance and anti-penetration effects on concrete is dependent on the numerical simulation, and the HJC model is often used in numerical simulations. On the basis of introduction about HJC model, parameter sensitivity analysis on HJC model by LS-DYNA numerical simulations is studied in the paper. There are five parameters (f_c, p_lock, A, B and N) are sensitive. According to the sensitivity parameters, it can improve the accuracy and quality of numerical simulation and the reasonable test methods and arrangements for testing chosen.

Using a two-stage light gas gun and shock recovery technique, a series of experiments up to 40-65 GPa were carried out on the nitrogen-rich material of precursor g-C₃N₄. The powder X-ray diffractions (XRD) of recovered samples showed that the precursor g-C₃N₄ was stable under 51 GPa pressure, while only a new crystalline phase β-C₃N₄ was obtained during 51-65 GPa pressure. The results confirm that β-C₃N₄ can be synthesized directly from precursor g-C₃N₄. This paper is significant for the study of synthesizing pure superhard carbon nitrides.

In some types of plasma, there did not exist an electrode or reference point. The electrode or reference point was needed when applying a bias voltage to a Langmuir probe. To acquire the characteristic parameters of transient plasma generated by hypervelocity impact, diagnostic system was established. The new electrostatic probe diagnostic system utilizing the double-Langmuir probe was given, in which no voltage and frequency sweep was required. This method can measure electron temperature and electron density as a function of time. This new instrument was based on a double-channel circuit, the current and voltage spectra were obtained from the probe synchronously by a digital oscilloscope. The aim of this work was to apply the double-Langmuir probe diagnostic system to time-dependent plasmas generated by 2024-T4 aluminum projectile hypervelocity impact 2024-T4 aluminum target.

The quasi-static and dynamic compression tests for Hf_44.5Cu₂₇Ni_13.5Ti₅Al₁₀ metallic glass were done by MTS810 and split Hopkinson pressure bar (SHPB) in the range of strain rate of 10^—4-10³ s^—1. The compressive stress-strain curves were obtained under varied strain rate and the fracture morphologies were studied by scanning electron microscopy. The experimental results show that the Hf_44.5Cu₂₇Ni_13.5Ti₅Al₁₀ metallic glsaa does not have the strain rate sensitivity under quasi-static compression. The dimple structure and periodic corrugations with about 60 nm spacing can be observed at the fracture surfaces which consist of radical zone and fan-shaped zone. Under dynamic compression, the yield strength rapidly declines with rise of strain rate, the metallic glass has the strain rate sensitivity. The fracture surfaces show floccule structure with vein-like patterns. Further observation reveals that dynamic compression fracture surfaces exist three fracture morphology: branch-like patterns, vein-like patterns and molten agglomerates.

A phase transition concerning lithium aluminate oxide (LiAl₅O₈) was observed. High pressure synchrotron radiation X-ray diffraction was used to explore its structure in a diamond anvil cell up to 47.0 GPa. We found the two phases are coexisted over a very large pressure range in the experiments. According to the analysis on the dynamic change of diffraction peaks with the increasing of pressure and the data reduction using indexed program, a new high-pressure phase of LiAl₅O₈ was identified at pressure below 45.0 GPa. This new phase has potentially a orthorhombic structure with a=0.995 9 nm, b=0.644 7 nm, c=0.333 4 nm and the space group of Pmm2.

As a novel non-thermal food processing technology, high hydrostatic pressure (HHP) is showing broad application in food industry. Compared to traditional technologies, this technology exhibits significant advantages in the retention of food quality, inactivation of microorganisms and enzymes. In this review, based on the comprehensive analysis, regulation of sub-lethal cells' membrane, genetic and structural components, metabolism under HHP treatment and a majority of sub-lethal food microorganisms general responses when exposed to some stresses are reviewed, and the stress response of sub-lethal food microorganisms exposed to HHP is discussed in this paper.

Using detonation-driven flyer, the samples of C₆₀ were shock loaded. For toluene extraction, the soot was examined by high performance liquid chromatography (HPLC). The results showed that most of C₆₀ was decomposed, a small part was changed into polymer, high fullerene, endohedral and other carbon cluster under shock wave high temperature high pressure. Under the shock waves of different intensity, the influence of the temperature and pressure on the decomposition and polymerization of C₆₀ were studied. The destruction mechanism of C₆₀ and the formation of the polymer of C₆₀ were also discussed.

In-situ high-pressure Raman study of the gypsum was carried out from 0 to 35 GPa with a diamond anvil cell (DAC). The authors determined the pressure dependences of the Raman bands of gypsum. A new Raman peak 1 012 cm^-1 in the stretching vibration of range is found at pressure of about 4.5 GPa, and its intensity is shown to strengthen with increasing pressure. So we can determine the occurrence of pressure-induced phase transition near 4.5 GPa.

The n-type nonstoichiometric PbTe(Pb_0.55Te_0.45) materials were prepared by the high pressure sintering process. The emphasis of the present study is on the influence of the pressure on the thermoelectric properties of the material. The experimental results show that the lattice defects are removed by high pressure sintering process, and it effectively adjusts the carrier concentration and its transport properties. Compared with the melting ingots, the Seebeck coefficient of the high pressure sintering sample obtains enhancement largely, the electric conductivity slightly reduces, simultaneously the thermal conductivity is low, and therefore the figure of merit (Tα²σ/κ) of the high pressure sintering sample is greatly enhanced. Therefore, the maximum the figure of merit of the sample prepared by 2 GPa reaches 0.59 at 700 K, which is about 150% improvement in comparison with the melting ingot.

Stainless steel mesh/Al multi-shock shield was designed by improving Al Whipple shield, and a series of high-velocity impact experiments were conducted by a two-stage light gas gun facility. Impact velocities of Al-spheres varied between 3.93 km/s and 4.25 km/s. The diameter of projectiles was 6.35 mm. For the different shield configurations with the same stainless steel mesh, the same shield configurations with different stainless steel mesh and the filmed stainless steel mesh shield configurations, the structure and material factors affecting on performance of shield were analyzed. The results indicated that when the stainless steel mesh wall was located in the last wall site of the bumper, it could help dispersing debris clouds, reducing the damage of the rear wall. At the same time, when the stainless steel mesh wall was located in the first wall site of the bumper, it did not help comminuting and decelerating projectile. The mesh opening size, wire diameter and separation distance arrangement were the important factors to enhance the protection performance of shields. The filmed stainless steel mesh helped in weakening the kinetic energy of debris cloud.