The High Energy Photon Source (HEPS) located at Huairou’s Science City in Bejing, one of the key projects listed in the “13^th Five-year Plan for national major scientific and technological infrastructure”, has been under construction since 2019. HEPS will be a world-leading 4^th generation high energy synchrotron radiation source featuring very low emittance, very high brilliance and high X-ray energy (about 300 keV).The new light source will provide X-ray probes with smaller size, higher brightness and better coherence for scientific researches. Synchrotron radiation technology has helped researchers achieve rich results in high-pressure research. In turn, the demand for high-pressure research is also promoting the development of synchrotron radiation experiment technology. In this paper, the design of the beamlines in the HPES phase I for high-pressure research are introduced, including a high-pressure beamline, an X-ray absorption spectroscopy beamline, a hard X-ray high energy resolution spectroscopy beamline and a transmission X-ray microscopy beamline. It is expected to help users well understand the functions of these beamlines, and further promote the development of synchrotron radiation high-pressure research together with the user community via seamless integration of techniques and users’ various requirements for advancing high-pressure science.

The combination of synchrotron X-ray radiation and static high pressure technology based on diamond anvil cell (DAC) and large volume press (LVP) has fundamentally promoted the development of high pressure science. Shanghai Synchrotron Radiation Facility (SSRF) is one of the advanced third generation light sources in the world, the hard X-ray micro-focusing beamline (BL15U1) of SSRF provides a monochromatic micro X-ray beam with high flux and adjustable energy, whose spatial resolution reaches the order of micrometer to submicron, and it has considerable advantages in DAC high-pressure experiments. Since it provided beamline time to high-pressure researchers in 2010, a series of influential achievements have been produced by using the related high pressure experimental methods at BL15U1. Moreover, the ultra-hard X-ray multi-functional beamline (BL12SW) in SSRF phase II is equipped with 200 t and 2000 t of LVP, which is a powerful platform for LVP experiments. In order to promote high pressure researchers to have a full understanding of the high pressure beamline at SSRF and make better use of relevant platforms to carry out research work, as well as to put forward valuable suggestions for the follow-up beamline construction and the development of experimental methods. In this paper, the layout, beamline specifications, main facilities and related experimental methods of BL15U1 and BL12SW beamlines are introduced in detail.

Synchrotron radiation source can offer wide-spectrum, high-energy, high-brightness, and low-emittance, which has been widely used in high pressure research. Among the X-ray techniques, the X-ray diffraction is one of the most basic and widely used experimental techniques, and is likely to remain the dominant application for high-pressure research in the future. Here the unique properties of synchrotron radiation, the basic composition of the light source, and the concepts of beam lines and experimental stations are briefly introduced. The high-pressure X-ray diffraction based on diamond anvil cells is focused. Various diffraction methods are explained, including powder diffraction, single X-ray diffraction and radial X-ray diffraction, as well as the combination with the laser heating and fast loading techniques. The equipment configuration and the capabilities of the high-pressure beamline at the Beijing Synchrotron Radiation Facility (BSRF) are also described, including the quality of radiation from 4W2 wiggler, X-ray micro-focusing, various diffraction methods and newly developed techniques. At last the opportunities brought by the construction of High Energy Photon Source (HEPS) for high pressure research are prospected.

FENGHUANG diffractometer at CMRR is a neutron diffractometer dedicated for high pressure experiments. After updating the neutron guide and monochromator, now the neutron flux at the sample position can get increased up to 2.84×10⁶ ns^–1·cm^–2.Based on the FENGHUANG diffractometer, comprehensive high pressure devices and techniques have been developed, such as gas cells, piston cylinders cell, clamp cell, PE press (VX4), opposite anvil press (HP3-1500) along with sample heating and cooling system, and the alignment system for high pressure devices. Moreover, with the modified high pressure and high temperature cell assemblies, the pressure can be up to 34 GPa while the temperature reaches 1500 ℃ at maximum in the angle-dispersive neutron diffraction. Recently, some scientific research have been performed, like the solubility of NaCl at high pressure, the intergranular strain evolution of HMX, and the pressure-induced polymerization. All these experimental experiences from FENGHUANG diffractometer could not only help to promote the development of high pressure techniques on neutron scattering facilities, but also contribute to the users for their high pressure studies.

Magnetotelluric (MT) surveys reveal that high conductivity layer appear in the upper crust beneath Tibet. Granite is the main rocks composed of upper crust, playing an important role in the process of crustal evolution. Electrical conductivity of granite during partial melting is of great significance to understanding the conductivity structure of Tibetan Plateau crust and the crustal evolution process. Electrical conductivity of granite collected from the Tibet was conducted under the conditions of 0.5－2.0 GPa and 773－1 373 K. The activation enthalpies of 1.01－1.09 eV and 2.16－2.97 eV are derived from 773 to 1 223 K and from 1 223 to 1 373 K, respectively. The change of activation enthalpy in different temperature zones may be related to the partial melting of granite induced by the biotite dehydration. Combining the experimental results and geothermal gradient of Tibet, we found that the experimental conductivity values fell between 0.016 S/m and 0.310 S/m in the temperature range of 973－1 223 K, which was in good agreement with the magnetotelluric sounding data. This may indicate that there is a close relationship between the genesis of the high conductivity layer and the partial melting of granite.

The effect of pressure on quenching process of commercial pure titanium (CPTi) has been studied.Annealed, water quenched and high temperature and high pressure (HTHP) treated samples were prepared for comparison. The phase composition and microstructure were analyzed, and the microhardness was measured. Results showed that under high pressure quenching, specimens were all α-Ti martensite, and the grain refinement and microhardness were increased with the increasing pressure. For the pressure treated sample, there was no elevation on hardness compared with water quenched sample. Besides, the elongation of water quenched specimen was quite lower than that of the as-received sample. Herein, to investigate the ductility and tensile strength, tensile test was carried out by using samples treated by self-heating process under high pressure. The data showed that the strength of the treated sample was substantially promoted and the ductility was good, which was close to as-received sample.

The shock-ramp wave loading experiment is fulfilled using pulsed power generator CQ-4. For RDX single crystal samples with the orientations of (210) and (100), the interfacial velocity profiles between the RDX sample and LiF window are obtained by photonic Doppler velocimetry (PDV). The experimental results show that the interfacial velocity profile is divided into three parts: shock compression, ramp wave compression and unloading waves. At the shock pressure of 4 GPa, an elastic-viscoplastic waveform is observed. When the shock pressure is as high as 7 GPa, the characteristic waveform corresponding to the elastic-plastic transition disappears in the measured wave profile.

In view of the problems of local corrosion, uniform corrosion and pipe body cracking of coiled tubing (CT) in formation containing CO₂ and high-temperature and high-pressure gas well, the CT corrosion failure was investigated firstly, and the corrosion failure mechanism was analyzed. The numerical model of CO₂ electrochemical corrosion of CT was established by COMSOL multifield coupling analysis method, and the influence of environmental factors on the corrosion rate was researched. The experimental result was compared with the numerical result. The result shows that the minimum error between the experimental corrosion rate and that of the numerical simulation is 1.3%. When the partial pressure of CO₂ is 0.1, 0.5 and 1.0 MPa, the corrosion rate of CT reached its peak at 120, 90 and 60 ℃, respectively. When the partial pressure of CO₂ is 0.1 MPa, and the electrolyte solution conductivity is 2.86, the corrosion rate of CT is higher at smaller pH value. This study is expected to provide suggestions for the safe use of CT in CO₂ corrosion environment.

Diamond/aluminum composites with a high thermal conductivity of 529 W/（m·K） were prepared using pure aluminum as the matrix and 50 vol.% Ti-coated 200 μm diamond as the filling material within10 min by high temperature (700 ℃) and high pressure (3 GPa) powder metallurgy method. The morphology and properties of Ti-coated diamond were characterized by optical microscope and X-ray diffraction. The properties of the prepared diamond/aluminum composite were tested by laser thermal diffusion instrument, scanning electron microscope and thermal expansion instrument. It is found that the Ti-coating diamond prepared by spark plasma sintering is mainly composed of titanium and a small amount of titanium carbide. Compared with raw diamond under the same preparation conditions, the Ti-coated diamond could effectively improve the thermal conductivity of diamond/aluminum composites. Meanwhile, the high temperature and high pressure method can be used to prepare the full density of diamond/aluminum composites, which can effectively improve the interface bonding between aluminum matrix and diamond particles, reduce the interface spaces and effectively improve the thermal conductivity of composites. Compared with the conventional methods such as vacuum hot pressing, spark plasma sintering and gas pressure infiltration, the sample preparation period of high temperature and high pressure powder metallurgy is short (several minutes). This research is helpful to expand the preparation method of high thermal conductivity composites, expand the product types of domestic six-sided top press, and provide technical support for the preparation of other metal matrix thermal conductive composites.

In order to study the influence of thickness and structure configuration of hollow tempered laminated glass on its impact resistance, DHR-9401 drop hammer impact testing machine combined with the method of minimum fragmentation energy was used in this experiment, and the impact effect was evaluated from the impact load peak, energy absorption rate and strain. The experimental results show that the glass as a bearing structure in daily life, its thickness and configuration have a great influence on its performance. Under the condition that the total thickness of the sample is the same or different, with the increase of the thickness of the impact layer, the impact resistance of the hollow tempered laminated glass is obviously improved. Under the premise that the total thickness of the sample is different, with the increase of the thickness of the inner glass, the bearing capacity of the hollow tempered laminated glass is improved obviously.

Because of their excellent lightness and crashworthiness, metal thin-walled structures have been widely used in the collision kinetic energy dissipation system of vehicles such as automobiles, airplanes and trains. In this paper, the deformation mode, energy absorption capacity, specific energy absorption and average compression force of sunflower thin-wall sandwich structure under radial impact load in two directions are studied. The results show that the wall thickness, the number of petals, the loading speed and the loading direction of the thin-wall sandwich structure of sunflower have certain effects on the impact resistance of the structure. Under the condition of constant mass, with the increase of the thickness of the outer shell, the energy absorption efficiency of the thin-walled structure under the tip pressure is reduced. The specific energy absorption under gap side pressure was 44.6% higher than that under tip side pressure. With the change of the number of petals, the energy absorption efficiency of thin-walled metal structure has an optimal value.

Cellular materials, characterized by their light weight and energy absorbing, etc., have broad potential applications in the fields of loading-path control, explosion and impact protection. In this paper, the discrete element method of lattice-spring model is utilized to simulate the early impact response of PMMA cellular materials with different arrangement models of voids during the impact loading process. The early void collapse failure, stress distribution and particle velocity of materials with various arrangement models are investigated. Our results show that the arrangement of voids affect the particle velocity but not the shock wave velocity. The cracks are germinated in the area near the longitudinal direction of the void, and the failure mode of the void is mainly shear failure. In different arrangement models of voids, there is a phenomenon of shear cracks interpenetrating between the holes, which promotes the compression of the volume. The square lattice and triangular lattice arrangement models prominently slow the stress concentration and plastic deformation rate of voids in the nearby area. The square lattice, triangular lattice, decreasing arrangement and increasing arrangement significantly have a remarkable influence on the flatness of the shock wave front of PMMA cellular materials. The random arrangement is the most effective one to reduce the particle velocity, and the square lattice contributes most to the post-pressure reduction of the wave front.

In order to reveal the influence of impact loading on the microscopic pore structure of anthracite, the shock and stress waves of the impact stress in different attenuation processes were simulated by using the split Hopkinson pressure bar (SHPB) impact loading system, and the fractal characteristics of the pore structures of anthracite in different directions of Zhaogu No.2 Mine (vertical, parallel and 45° oblique to the bedding direction) were studied by using the fractal theory based on the test data of mercury intrusion and low-temperature liquid nitrogen before and after impacting. The results show that for the seepage hole, the impact loading increases the gas seepage and migration velocity. For the adsorption hole, the impact loading reduces the adsorption capacity of the adsorption hole, which promotes the desorption of gas. Fractal dimension has obvious impact directionality, and the fractal dimension of the adsorption hole is obviously smaller than that of the seepage hole; the optimal impact loadings of anthracite in different directions are different. The optimal loading in the vertical bedding direction and the oblique bedding direction is 51.80 MPa, and the optimal impact loading in the parallel bedding direction is 28.46 MPa. The research results can provide support for the discussion of the mechanism of impact loading to promote gas drainage.

In order to accurately fit the failure criteria in JC failure model, BW failure model, and MMC failure model, numerical simulations for metal materials Q345B and 921A under various loading conditions of compression, torsion, tension were performed in this work. The variation of stresses, indicated by stress triaxiality and Lode parameter, was investigated during the fracture progress. The results indicated: (1) exclusive of torsional loading, the stress distribution varied in the cracking plane as the crack growth; (2) the average stress triaxiality and Lode parameter are more suitable for describing the stress status; (3) for specimens having the same size, the value of average stress triaxiality was dependent on metal properties. This work would provide useful knowledge for obtaining the failure criterion from material failure experiments.

In order to study the penetration performance of small tungsten spheres on the human equivalent target with body armor, the test of small tungsten spheres penetrating 25 mm thick pine target with Class Ⅲ soft body armor is carried out. On this basis, the equivalent relationships between 25 mm thick pine target with Class Ⅲ soft body armor and LY-12 hard aluminum target are studied by combining the experiment and numerical simulation of small tungsten spheres penetrating LY-12 hard aluminum target. According to the method of dimensional analysis, the ballistic limit prediction formula of small tungsten spheres penetrating 25 mm thick pine target with Class Ⅲ soft body armor is established and the influence of the mass change of small tungsten spheres on the penetration performance is studied. The experimental results reveal that for the penetration of small tungsten spheres, a 25 mm thick pine target with Class Ⅲ soft body armor can be equivalent to a 6.2 mm thick LY-12 hard aluminum target. The predicted value of ballistic limit prediction formula is in good agreement with the test value. And with the increase of the mass of tungsten spheres, the ballistic limit approximately obeys the law of decreasing power function. The research results have certain reference value for the improvement and design of individual fragment warhead.

A deflagration experiment of methane/air premixed gas with or without wire mesh was carried out in the self-design square pipe. The effects of the mesh number and layer number of the wire mesh on the deflagration overpressure and temperature were discussed. The results show that the wire mesh can effectively suppress the temperature and overpressure of the deflagration flame. After the wire mesh is installed, the temperature peak and the overpressure peak measured in the pipeline are reduced compared to the case without wire mesh, and the temperature peak attenuation rate reaches 52.37%, the peak attenuation rate of overpressure reaches 66.84%; the mesh number and layer number of the wire mesh are important factors that affect the suppression effect of the wire mesh on overpressure. When the number of layers and meshes are small, the time to reach the peak of the overpressure is earlier than the condition with no wire mesh; when the number of layers and meshes are moderate, the secondary peak appears in the overpressure curve; when the number of layers and meshes are large, the overpressure is effectively suppressed. With the increase of the number of meshes and layers, the flame heat diffusion rate forward becomes slower, and the start time of the temperature curve is delayed compared to the time delay without the wire mesh.

Thin-walled tube is a common energy-absorbing structure. The introduction of folds in thin-walled tube can induce the deformation of thin-walled tube, reduce the initial peak force of buckling of thin-walled tube and improve the energy absorption of thin-walled tube effectively. At present, when the folded tubes subjects to axial compression, the crushing force decreases significantly after the initial peak force, which lowers the energy absorption performance of folded tubes. In order to further reduce the initial peak force and increase the total energy absorbed of the folded tube, different forms of folded tube are introduced into the square tube to obtain a folded shrink tube. The relation between force and displacement and deformation of the designed folded tube under the quasi-static compression is obtained by using ABAQUS/Explicit. The results show that the collapse force of the folded shrink tube is in the form of a gradient during the compression process. Compared with traditional square tube and diamond tube, the folded shrink tube not only has lower initial peak force, but also can greatly improve the total energy absorption. The influence of geometric parameters on the performance of the folded tube was studied systematically. The best performance folded shrink tubes were obtained.

In the field of biomass resource utilization, the steam explosion technology serves as the key technology to break the anti-degradation barrier of biomass and realize biorefineries, which is characteristic of clean, short-term and high efficiency. In this paper, the energy composition and transformation in the process of biomass steam explosion was analyzed using the basic principle of heat transfer, and an energy consumption model of biomass steam explosion was established to clarify the mechanical work of steam heat energy conversion and verify the consumption factors affecting the pretreatment enery of biomass steam explosion. It was shown that in the process of biomass steam explosion, the established model can not only accurately reflect the heat energy utilization and transformation process, but also quantitatively analyze the change law of material moisture content, steam explosion intensity and energy consumption of the charging amount. This study provides a theoretical reference for the steam explosion technology’s application into the industrialization of biofuel or biorefineries.