The electrical explosion of metal bridge foil is a key physical process in many fields, e.g. electric guns and slapper detonator. Due to the complexity of material properties, dynamic processes, and effects of geometric configurations, a large amount of earlier theoretical simulations used simplified physical models. In this paper, a three-dimensional electromagnetic-thermal-mechanical model was established. which was a full physical model describing the early behavior of explosive foil. The early thermal expansion process of the explosive foil under large current loading was simulated, and the evolution of magnetic field, current, temperature, expansion speed of the foil was analyzed. The phenomena of angular and linear current diffusions induced by the configuration and the resistivity were observed in the simulation. The temperature distribution in the bridge region obtained from the simulation is qualitatively consistent with experiment and simulation results of literature.

In this paper, we reviewed the recent progress on the high-pressure synthesis of Pb-based simple perovskite compounds PbMO₃ (M=3d transition metals) and the investigation on their physical properties, mainly focusing on the M dependent crystal structure, electronic configuration, magnetism, transport properties, pressure induced structure phase transition, charge transfer and insulator to metal transitions. We also gave a comment on the unresolve problems in this system.

Three obstacles with different levels of bending strength was selected for experimental research on the impact of hydrogen-methane mixed gas explosions in order to explore the varying environmental hazards of explosion promotion. During the experiment, the images of the flame in the explosion pipeline and the upstream and downstream pressure were collected. Through the analysis of flame images and explosion pressure data, the flow field accelerated by expanding gas after explosion generates eddy currents behind obstacles, and the flow field produces different eddy currents behind obstacles of different materials, which result in the difference of peak flame velocity of gas in the later stage and the difference of explosion overpressure in pipelines. This proves the correlation between the intensity of promoting explosions and the material of obstacles. In the experiments conducted in this paper, there is a proportional relationship between the intensity of promoting explosions and the bending strength of the obstacle. Moreover, after hydrogen was added, the reaction of the gas base was accelerated and the peak explosion pressure in the obstacle pipes of the three materials began to produce obvious differences. It can be concluded that obstacles and rough walls in the environment will affect the gas explosion effect, and the difference is caused by the characteristics of the material itself, and the difference is affected by the combustion rate of the gas itself.

The copper-based rare-earth perovskites La_1–xNd_xCuO₃(0≤x≤1) have been synthesized in the two-stage Walker-type high-pressure apparatus. The refined crystal structure results revealed that La_1–xNd_xCuO₃ (0≤x≤0.4) adopts a rhombohedral structure with the space group $R\overline 3 c $. When 0.5≤x≤0.7, a mixed phase with both $R\overline 3 c $ rhombohedral and Pnma orthorhombic structures was observed in the system. With a further increase in Nd³⁺ doping, the system exhibits a single Pnma orthorhombic phase when x=0.8, 0.9 and 1. A comprehensive structural phase diagram of La_1–xNd_xCuO₃ (0≤x≤1) was established in this study, providing a new material platform for investigating the magnetic properties, metal-insulator transitions, and other physical property evolutions in rare-earth 3d transition metal oxides.

Compared with the traditional reinforced concrete and profiled double-skin composite wall (PDSCW), concrete-infilled double steel corrugated-plate wall (CDSCW) has better axial compressive capacity, lateral flexural stiffness, impact resistance and seismic performance, which has broad application prospect in ship and military field. In this paper, two types of CDSCW specimens were designed and produced. Firstly, the damage modes and dynamic responses of the two specimens were analyzed and compared through near-field explosion test. Secondly, the finite element model of CDSCW was established by using ANSYS/LS-DYNA software. The damage mechanism and explosion response of CDSCW and PDSCW under near-field explosion were studied, and the results were compared with the test results. Finally, effects of concrete thickness, steel plate thickness and charge quantity on the anti-blast performance of corrugated double steel plate composite wall board were analyzed. The results show that, compared with PDSCW, CDSCW with the same concrete and component size (length and width) have greater flexural rigidity, energy dissipation capacity, and better knock resistance performance under near field explosion. Increasing the corrugated depth can effectively improve the anti-blast performance of CDSCW, which provides reference for the design of anti-blast component and related engineering research.

The bubble curtain can effectively weaken the influence of underwater shock wave on the surrounding environment. In order to investigate the synergistic effect of air supply volume and bubble curtain layer on the shock wave attenuation of underwater explosion, underwater explosion tests with one layer, two layers and three layers were designed under the air supply volume of 30, 60, and 90 L/min, respectively. The results show that the attenuance of bubble curtain increases with the increase of air supply volume and layer number. When the air supply is small (such as 30, 60 L/min), with the increase of the number of bubble curtain layers, the attenuation efficiency of the peak pressure between adjacent layers becomes worse; when the air supply is large (such as 90 L/min), with the increase of the number of bubble curtain layers, the attenuation efficiency of the peak pressure between adjacent layers becomes better. Combined with the economic benefits of the actual project and the complex underwater environment problems to analyze the attenuation effect of the bubble curtain, it was determined that the two-layer bubble curtain with the air supply rate of 30 L/min was the optimal attenuation scheme, which provides reference and new ideas for related practical engineering problems.

To study the influence of crack inclination angle on the mechanical properties and the energy evolution mechanism during the rock failure, a calculation model was constructed based on the particle flow dispersion element numerical platform, and uniaxial compression numerical experiments were conducted on rock samples with different crack inclination angles. The research results indicate that as the crack inclination angle increases, the peak strength and elastic modulus of fractured rocks show a “V” shaped trend of first decreasing and then increasing. When the crack inclination angle is small, the rock sample mainly undergoes shear failure and vertical splitting failure, and the number of tensile and shear cracks mainly increases in a stepped pattern. The larger the crack inclination angle, the more the rock failure mode will transition to a mixture of vertical splitting and shear failure, and the curve of the number of tensile and shear cracks will increase exponentially. As the crack inclination angle increases, the total input energy and elastic strain energy of the rock sample show a trend of first decreasing and then increasing. The larger the crack inclination angle, the faster the increase in dissipated energy, but the lower the final dissipated energy when the rock sample fails. The existence of cracks significantly weakens the energy storage limit, weakens the ability of the rock to absorb and store elastic strain energy, and enhances its energy dissipation ability at peak stress in the rock specimen during compressive failure.

Artificial plastic hinges have been widely used in the seismic research of frame structures, which can control the location of the beam plastic hinges and avoid the continuous collapse of the frame structure due to the damage of beam-column joints in earthquakes. The design goal of “strong column weak beam” can be achieved. An artificial plastic hinge with kinked rebar provides a new idea for structural blast resistance. Established structural static load tests have shown that the kinked rebar has excellent deformation performance. The ultimate load capacity of beam with kinded rebar is not reduced. With the software ANSYS/LS-DYNA and the hybrid finite element modeling approach, a numerical simulation study of reinforced concrete frame structures with different kinked rebar schemes was carried out. The results showed that the beam with kinked rebar can absorb the impact energy, reduce the support reaction, delay the peak reaction force, protect the beam-column joints, limit the damage to beam-slab members, and prevent the continuous collapse of frame structre.

Double perovskite Y₂NiIrO₆ is a ferrimagnetic material with Curie temperature of 192 K. It has drawn wide attention owing to its remarkable exchange-bias effect. Here, we studied the low-temperature crystal structure, electron transport properties and magnetoresistance of Y₂NiIrO₆. The crystal structure under 130 K is almost identical with that of room-temperature. The material shows semiconducting behavior in the temperature range of 130 to 300 K. Above Curie temperature it can be well describe as Efros-Shklovskii variable-range hopping model. Below Curie temperature, a departure occurs due to the forming of long-range ferrimagnetic ordering. It is interesting to find that the magnetic ordering results into negative magneto-resistance. Moreover, giant magnetoresistance up to –10% is induced by cooling field of 7.0 T. This mechanism of this remarkable effect provides a new boulevard to discover new type of giant magneto-resistance materials.

We present a theoretical approach for predicting the electron configuration, polymorph, synthesis condition, and physical properties of complex magnetic double perovskite compounds. Our method is reasonable and computationally efficient, allowing us to identify an antiferromagnetic (AFM) metallic material, namely Mn₂FeOsO₆, with a high AFM Néel transition temperature (T_N). Through extensive analysis, we demonstrate that Mn₂FeOsO₆ possesses a high density of states near the Fermi level and an AFM configuration, resulting in a zero total magnetic moment. Our findings suggest that the expected T_N of Mn₂FeOsO₆ is as high as 680 K, representing a potential breakthrough in the field of spintronics. We have also constructed a sophisticated magnetic model for this material, and obtained a reasonably reliable magnetic excitation spectrum potentially comparable with neutron scattering spectra. This theoretical approach provides synthesis conditions that are consistent with many synthesized double perovskite compounds in experiments, and it holds promise for the prediction of other complex magnetic configurations. Our study may play a key role in the big data prediction of novel double perovskite materials.