The various hybridization states of carbon atoms endow carbon materials with complex structures and properties. Finding and developing carbon materials with new structures and realizing accurate and controllable synthesis of carbon materials are important directions in the carbon materials research area. High pressure (above 1 GPa) can effectively reduce the intermolecular distances and promote the polymerizations of unsaturated molecules, which provides a new strategy and opportunity for “bottom-up” synthesis of carbon materials. The chemical reaction under high pressure is generally the solid phase reaction and the reaction molecules are constrained by the lattice, which shows the characteristics of topochemical reaction. This means that we can adjust the reaction routes by controlling the crystal structures of reactants to synthesize carbon materials with specific structures and functions. In this review, we report the progress in the synthesis of carbon materials by high pressure solid-state topochemical polymerization, such as polyolefin, acetylenic polymer, diamond-based carbon nanothreads, carbon nanoribbons, graphane and high-charge ionic polymers, and briefly introduce the characteristics and mechanism of chemical reaction under high pressure.

The quantum precision magnetic measurement in high-pressure environments is of great significance for studying the evolution and structure of matter under an extreme environment. Given the challenges associated with achieving in-situ high-resolution magnetic detection under high pressure by using traditional methods, the proposed high-pressure quantum magnetic measurement based on solid-state color centres has made significant progress in recent years. This advancement is of great significance in advancing the study of matter under high pressure. And this paper primarily focuses on the research of quantum magnetic measurement using SiC color centres under high pressure. The optical and spin properties of silicon vacancy defects and divacancy defects in SiC under high pressure is reviewed. Furthermore, the magnetic phase transition of Nd₂Fe₁₄B is observed, and the critical temperature-pressure phase diagram of the superconductor YBa₂Cu₃O_6.6 is mapped out. This work reviews and highlights the potential of silicon vacancy-based quantum sensors for in situ magnetic detection at high pressures. Its applications in pressure sensing, pressure-induced magnetic phase transformation and pressure-induced superconducting transformation are also presented.

Indentation techniques based on atomic force microscopy (AFM) have been widely used in characterizing the mechanical properties of various types of materials, due to their high lateral resolution and vertical precision. This review article begins with a concise introduction to the fundamental principles of AFM and related indentation techniques. Subsequently, it extensively discusses and reviews the applications of AFM-based indentation techniques in measuring the mechanical properties of low-dimensional materials, biological materials, etc. This article also reviews the latest progress of the applications of AFM in the research of high-pressure phase transition in two-dimensional materials. Particularly, we introduce a novel angstrom-indentation technique, which enables atomic-level deformation on the samples. Angstrom-indentation allows for highly effective characterization and tuning of the interlayer coupling in two-dimensional materials. Finally, we make an outlook on the development of AFM-based indentation techniques.

Polycrystalline Na_0.5K_0.5NbO₃ ceramics were prepared under the condition of 10 GPa and 1050 ℃. The compression and shear wave velocities of the samples under various hydrostatic pressures were measured using ultrasonic interferometry. By fitting the third-order finite strain state equation, the bulk and shear moduli of polycrystalline Na_0.5K_0.5NbO₃ and their pressure dependency were determined as 172.6 GPa, 54.6 GPa, 0.3 and 2.1, respectively. The sample shows a positive pressure dependence of Young’s modulus. Based on the elastic modulus data, the Poisson’s ratio was obtained as 0.342, indicating that the material was ductile and shows brittleness under high pressure. The Vickers hardness and fracture toughness also show positive pressure dependence. Using the empirical models, the Vickers hardness and fracture toughness of the ceramics were obtained as 2.40 GPa and 2.33 MPa·m^1/2. Meanwhile, based on the elastic wave velocity and density data, the Debye temperature (513.1 K) and the Grüneisen constant (2.113) of Na_0.5K_0.5NbO₃ ceramics were derived. Our results provide an experimental reference for evaluating the acoustic and elastic-related comprehensive properties of Na_0.5K_0.5NbO₃ under high pressure, and a foundation for its engineering applications under extreme high-pressure conditions as well.

A nanosecond pulsed laser ablation platform of SiC material and a nanosecond pulsed laser induced plasma experimental system were established. One dimensional fluid mechanics code was used to simulate the dynamic process of plasma jet generated by high power laser during the ablation of SiC material. The nanosecond pulsed laser ablation rule of SiC material was obtained, and the effect of laser induced plasma on ablation depth was verified through experiment and numerical simulation. The research results can provide reference for material engineering applications related to nanosecond laser ablation.

To determine the parameters of equation of state for detonation products of the HNS-based explosive PBX-1, the plane wave lens and the photonic Doppler velocimetry (PDV) were used to measure the free surface velocity histories of metal plates driven by the PBX-1 explosives. The explosive samples had diameters of 6 mm and different lengths. According to the experimental results, the detonation velocity of PBX-1 is about 6798.2 m/s, and the effective explosive volume is obviously affected by the ratio of length to diameter of explosive sample. Compared with the sample with the ratio equal to 1, the effective explosive volume of the sample with the ratio equal to 2, leads to a lower maximum plate velocity. The plate driven by the longer explosive sample is less affected by the initiation boundary of plane wave lens. Therefore, the experimental result obtained by the longer explosive sample was used to determine the detonation products’ parameters of equation of state by numerical simulation. The simulation showed that the simulated free surface velocity history is in good agreement with the experimental result. The obtained detonation products’ parameters of equation of state provides fundamental data for reliability assessment of slapper detonator.

The magnetically driven sample experiments which were carried out in an intense pulsed power device were simulated and analyzed by two-dimensional magnetically driven simulation code (MDSC2), and the structure coefficient of magnetically driven sample experiments was studied and analyzed. The numerical results show that MDSC2 can correctly simulate experiments of magnetically driven samples such as tin and magnesium-aluminum alloy. The simulated sample/window interface velocity (or flyer plate/window interface velocity) is basically consistent with the experimental measured one. The structure coefficients of magnetically driven samples are usually different when the magnetically driven sample experiments are different. The structure coefficient of magnetically driven sample experiment is related to the initial conditions such as the sample material and the width of the electrode plate but not to the initial thickness of the sample material. Under the same initial conditions, such as the thickness of the flyer plate, the material of the flyer plate, the material of the sample, the initial gap between the cathode and the anode, the wider the electrode plate, the larger the structure coefficient of the magnetic drive sample experiment. MDSC2 can correctly simulate the magnetically driven sample experiments, which makes MDSC2 an important tool for the study of magnetically driven sample experiments.

In shockwave experiments, the launch velocity of flyer is a crucial parameter for determining the physical quantities in sample under dynamic compression. Magnet velocity induction system is used to determine the velocity of flyer which can work under hypervelocity conditions. Based on finite element method, ANSYS Electromagnetics Suite module was used to establish a three-dimensional model and the launch process of flyer was simulated. The simulated results well reproduce the experimental signals. Comparing to the experimental results, the relative error of simulated amplitude of induced electromotive force (AIEMF) is 1.1%, lower than the system error of 2.0%. The relative error for flyer velocity determined by simulation is less than 0.4%, also lower than the measurement system error of 0.9%. The dependence of AIEMF with the thickness, radius, tilt angle, launch velocity of flyer and the diameter of pick-up coils is analyzed. The simulation result provides a reference for better signal acquisition in shockwave experiments.

In order to improve the thermal stability of 2,6-diamino-3,5-dinitropyridine-1-oxide (ANPyO), polydopamine was coated on the surface of ANPyO crystal by in situ polymerization, based on the principle of dopamine oxidation self-polymerization. ANPyO@PDA core-shell composite materials with different coating rates were prepared by adjusting the reaction time. The morphology, crystal structure, molecular structure, and element content of ANPyO@PDA composites were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The thermal decomposition performance of the ANPyO@PDA composites was also tested by thermogravimetry-differential scanning calorimetry (TG-DSC). The results show that PDA formed uniform and compact coating on the surface of the ANPyO, and the crystal and molecular structures of the ANPyO remained unchanged after the PDA coating. Additionally, the coating rate gradually increased with the growth of coating time. The thermal decomposition peak temperatures of the ANPyO were increased by 1.97 and 1.95 °C, respectively, as well as the apparent activation energy increased by 25.04 and 139.33 kJ/mol, and the critical temperatures of the thermal explosion were increased by 23.12 and 20.04 ℃ after PDA coating for 3 and 9 h, respectively. The thermal stability and thermal safety of the ANPyO@PDA composites are higher than that of the ANPyO.

There is a clear correlation between the ballistic performance of ceramic/fiber composite armor and the fragmentation characteristics of the projectile and target. When the back-plate material is different, the difference in wave impedance will cause differences in stress wave transmission between the ceramic and back-plate interface, resulting in different fragmentation outcomes of the projectile and ceramic panel, leading to differences in the protective performance of the composite target. For the differences in the fragmentation characteristics of the projectile and target, when the projectile penetrates different fiber back-plate ceramic composite armors, ballistic tests of 12.7 mm armor-piercing incendiary projectile penetration of ceramic/Kevlar fiber composite targets and ceramic/carbon fiber composite targets were carried out, and the protective performance of the two types of ceramic/fiber composite targets was analyzed in conjunction with the test results and the Rosin-Rammer distribution model. The results show that the fracture of the bullet core is mainly caused by the internal shear stress. When the back-plate material is carbon fiber, the average characteristic size of the bullet core fragments is reduced by 21.68% compared with Kevlar fiber, and the average characteristic size of the ceramic fragments is reduced by about 9.48%, that is, the proportion of small-sized fragments of the bullet core and ceramics is larger, and at the same time, the overall ballistic performance of the composite target is better.

The deep coal mine blasting is the combined action of the initial ground stress field and the explosion load. By using the unidirectional dynamic and static combined loading test platform and the dynamic caustic experimental system, the expansion law of the initial stress field intensity on the blasting crack is explored under the horizontal or vertical unidirectional confining pressure applied to the blasthole notch on the plexiglass plate. The test results show that the grooving of the blasthole can effectively control the distribution range of the initial stress field, promote the concentrated release of energy, and improve the directional blasting effect. At the same time, the dynamic effect of explosion and the static effect of confining pressure are dominant in the near and far areas of the blasthole, respectively. The horizontal initial stress field increases the stress concentration at the crack tip and promotes the growth of the main crack. With the increase of the stress field, the promotion effect is more obvious, and the occurrence of secondary cracks is inhibited. In contrast, the vertical initial stress field reduces the stress concentration at the notch tip, inhibits the crack propagation, and transforms the crack from type Ⅰ fracture to type Ⅰ-Ⅱ mixed fracture. With the increase of stress field, the shear fracture is more obvious, and the crack propagates along the direction of the maximum principal stress.

During the construction process of pile driving on nearshore slope, it is crucial to accurately assess the impact of dynamic loading from the pile hammer on the stability and safety of the slope’s supporting steel sheet pile structure. In the case of the first phase of the dock project at Huarong, a dynamic finite element numerical simulation method was employed to establish a computational model for the double-row suspended steel sheet pile structure. Through field vibration testing verification, the dynamic response characteristics of the double-row steel sheet piles under the influence of pile hammer impact were analyzed, enabling the evaluation of the safety of the double-row steel sheet piles. The research findings revealed that the displacement deformation of the steel sheet piles had little correlation with the impact location of the hammer. The maximum displacement of the lower row of steel sheet piles was 3.14 cm, while the maximum displacement of the upper row was 2.51 cm. The maximum principal stress had no significant relationship with the impact location, and the maximum principal stress of both the upper and lower rows of steel sheet piles was less than 20 MPa. The maximum von Mises stress occurred at the intersection between the steel sheet pile and the vertical line passing through the impact point of the hammer. The maximum von Mises stress for the upper row of steel sheet piles was 20.85 MPa, while for the lower row it was 25.40 MPa. The displacement deformation and stress of the double-row steel sheet piles remained within the safe control range.

Metal thin-walled tubes are widely used in vehicles as energy absorption structures. Improving the energy absorption characteristics of thin-walled tubes is of great significance for enhancing the passive safety of transportation vehicles. In this paper, a combination of multi-corner and multi-cell structures of single and double corrugated multi-cell tubes were proposed. The influence of corrugation amplitude and corrugation number on the energy absorption characteristics of the corrugated multi-cell tube were studied by numerical method. It was found that the energy absorption of the corrugated multi-cell tube is improved compared with that of traditional square multi-cell tube. In addition, the double corrugated multi-cell tube has a more stable deformation and a higher energy absorption than the single corrugated multi-cell tube. Finally, the optimal structure was selected to study the influence of rib position and node reinforcement. The results show that the edge-to-edge connection has the best energy absorption characteristics, and the node reinforcement at the rib could further improve the energy absorption of the double corrugated multi-cell tube. Compared to traditional square multi-cell tube, the energy absorption of node-strengthened double corrugated multi-cell tube increases by 88.17%, and the crushing force efficiency increases by 65.91%. The node-strengthened double corrugated multi-cell tube has better energy absorption characteristics than traditional square multi-cell tube, leading to broad application prospects as crashworthiness structures.

In order to study the gas leakage in a confined space and the effect of venting methods on the subsequent explosion, a major gas accident scene in confined space was constructed based on FLACS software. The leakage, diffusion, and explosion behavior of the leaked gas in the confined space was investigated, and the venting effect on the subsequent explosion was analysed. The results showed that the leaked gas cloud from the closed section of the pipeline diffuses outward along the outer wall of the pipeline, forming an irregular concave shape, and the diffusion speed will be accelerated when encountering obstacles. The maximum overpressure of leaked gas cloud is 660.7 kPa, which can seriously damage the surrounding buildings, and the degree of damage to the buildings at the open end of the restricted space is higher than that at the closed end. When the outlet is installed in the axial position of the flame development, the pressure-venting effect is the best. The maximum explosion pressure in the confined space can be reduced to 312.4 kPa, a reduction of 52.70%. If the outlet is placed on the side of the confined space, the closer it is to the ignition source, the better the venting effect will be. The maximum explosion pressure in the confined space can be significantly reduced by increasing the length-to-width ratio of the outlet to expand the explosion area. When the length-to-width ratio is 34∶1, the maximum explosion pressure is reduced to 15.4 kPa, a reduction of 97.65%. Reducing the outlet opening pressure can effectively reduce the maximum explosion pressure in the confined space. For the outlet opening pressure at 50 kPa, the maximum explosion pressure is reduced to 351.0 kPa, a reduction of 46.87%.

In order to obtain the optimal combination of pre-splitting blasting parameters to ensure the safety and stability of open-pit mine slope, the law of crack propagation under rock double-hole blasting was discussed by numerical simulation combined with similar model experiment, and the field pre-splitting blasting experiment was carried out. The results show that the cracks are first generated by the blasthole wall and the original rock near the blasthole is more damaged. As the decoupling coefficient increases from 1.33 to 3.00, the impact pressure on the hole wall decreases significantly, and the radius of the crushing zone decreases gradually. The range analysis method was used to study the influence of different factors on the experiment index, and the optimal combination of experiment factors was determined according to the evaluation index. The results of the model experiment indicate that the pre-splitting effect of the model specimen is the best under the combined conditions of the hole spacing-to-aperture ratio of 9, the decoupling coefficient of 3.00, the initiation delay time of 12 ms, and the maximum charge weight per delayed interval of 5.4 g (three holes and one shot). According to the results of numerical simulation and similar model experiment, combined with theoretical calculation, the pre-splitting blasting parameters with hole spacing of 0.8 m (the spacing-to-aperture ratio of about 9), decoupling coefficient of 3.00, delay time of 12 ms and maximum charge weight per delayed interval of 11.25 kg (three holes and one shot) were selected for field experiment, and good pre-splitting effect was achieved. The research results can provide reference for the design of pre-splitting blasting parameters in open-pit mines, and it is of great significance to realize accurate control blasting and ensure the safety and stability of open-pit mine slopes.

There are many influencing factors of bubble curtain clipping technology. In order to obtain the optimal combination of bubble curtain in engineering applications, AUTODYN software was used to design a three factor and three level orthogonal test. The average reduction rate of shock wave peak pressure was used as an evaluation index to study the influence and sensitivity of the number of bubble curtain layers, the burst distance of the bubble curtain and the charge depth on the bubble curtain clipping effect. The results indicate that the clipping ability of the bubble curtain has a great value, and there will be a negative effect if the number of bubble curtain layers continues to increase. The number of bubble curtain layers has the greatest effect on the clipping ability, followed by the charge depth, and the effect of bubble curtain explosion center distance is the smallest. The smaller the burst center distance and the greater the depth of the packet, the better the bubble curtain chipping effect. When the number of bubble curtain layers is 2, the bubble curtain burst distance is 1 m, and the charge depth is 10.5 m, the clipping effect is the best.

In order to promote the further practical application of rock mass explosivity classification in engineering, regression analysis method was used to analyze the correlation of explosivity indicators, and finally determine the four basically unrelated parameters of rock mass tensile strength, density, brittleness index, and integrity coefficient as rating indicators. The sensitivity of each rating index and its weight were determined using orthogonal design experiments. By using the method of fuzzy decision-making, the explosivity of rock mass was rated, and based on the rating index and the basic quality index of rock mass, a formula for predicting the explosive unit consumption of shallow hole blasting in underground mining was derived. The corresponding explosive unit consumption prediction interval for the explosivity level was further derived. This research shows that the fuzzy decision-making method provides a new approach for rock mass explosivity rating, and also proves the correctness of weight allocation and rating index selection. The on-site blasting test has proven the rationality of the predicted range of explosive unit consumption, which can provide certain guiding significance for production blasting and similar engineering practices.