Seismological and geodetic data indicate that the lunar core-mantle boundary (CMB) exhibits a well-defined low-velocity zone (LVZ) with a combination of anomalous seismic velocities and density that remain unexplained. Here, in-house high-pressure experiments simulating the interaction between mantle olivine and core iron at CMB conditions in conjunction with thermodynamic modeling demonstrate reactive formation of dense iron-rich magnesiowüstite [Mw, (Fe,Mg)O], a hitherto unrecognized lunar mineral. In-situ synchrotron ultrasonic measurements show that the seismic velocities and density of Mw, when incorporated in realistic proportions of ~5-15 wt% with mantle olivine plus minor silicate melt match the observed LVZ properties. Oxygen exsolution from core metal during cooling is the most likely driver of Mw formation, quantitatively yielding the required Mw proportions in the LVZ. These results suggest that core-mantle reactions can generate magnesiowüstite through oxidation of iron metal, offering a blueprint for the expected seismic properties of the CMB regions of rocky bodies that experience mantle oxidation after core formation.

Natural gas reservoirs characterized by high heterogeneity and containing bottom-bound water often face the problem of water intrusion, making it difficult to recover the recoverable gas. This paper addresses the issue of enhanced gas recovery in water-flooded reservoirs and, through high-temperature, high-pressure long-core displacement experiments, investigates the displacement effects of different reservoir properties and injection media (dry gas, N2, CO2) under simulated water-flooding conditions. The experiment utilized two sets of sandstone cores—one with moderate permeability (304.8 mD) and one with high permeability (1004.6 mD). Three cores from each set were spliced together to form a 0.9 m long core, simulating the gas injection and displacement process following water infiltration. The results indicate that while water intrusion occurs more rapidly in high-permeability reservoirs, gas injection yields better recovery results than in medium-permeability reservoirs. Among the three injection media, dry gas demonstrated the best displacement efficiency, followed by N2, with CO2 performing the worst. CO2 tends to react with highly mineralized formation water under high-temperature and high-pressure conditions, forming precipitates and causing energy to be absorbed by the water, which reduces displacement efficiency. It is recommended that dry gas injection be used for enhanced recovery in the moderate-permeability reservoirs of the Y gas field, while N2 injection may be considered for the high-permeability reservoirs to balance effectiveness and cost. The research results provide experimental support for subsequent gas injection to enhance gas recovery in this gas field.

Conventional chemical gel plugging materials often suffer from poor high-temperature stability and inadequate mechanical properties. To address these issues, this study developed a high-performance composite gel material using a multi-component hybrid crosslinking strategy. The material employs γ-methacryloxypropyltrimethoxysilane (MPTMS) as the silica source, which hydrolyzes in situ to generate SiO2, thereby enhancing temperature resistance. Laponite nanoplatelets are incorporated as a toughening agent and physical crosslinking points, while a self-synthesized reactive microgel (BWL) serves as the organic crosslinking core. Through copolymerization with monomers such as acrylamide (AM) and methacrylic acid (MAA), a triple-crosslinked network structure is constructed. Compared with conventional gels, the synthesized hybrid crosslinked composite gel maintains a high storage modulus and loss modulus after aging at 140 °C and exhibits excellent tensile and compressive properties. Furthermore, the gel was processed into particle-based lost circulation materials with different particle sizes. High-temperature and high-pressure plugging experiments demonstrate that when using a mixed system of 40-60 mesh, 20-40 mesh, and 10-20 mesh gel particles with a total concentration of 2%, it can effectively seal highly permeable sand beds and fractures with apertures up to 5 mm. This meets the engineering requirements for lost circulation materials with high strength and high stability in deep, high-temperature formations.

Abstract The spin polarization and spatial homogeneity of alkali metal atoms are critical characteristics that determine the performance of spin-exchange relaxation-free (SERF) magnetometers. In buffer gas cells, these characteristics are influenced by optical broadening and alkali atomic motional restriction imposed by the buffer gas. In coated cells, the protective effect of the coating on atomic spins, combined with rapid atomic diffusion, leads to significantly superior spin polarization characteristics compared to those in high-pressure buffer gas cells. However, due to neglecting the influence of atom-coating interactions on atomic motion, the existing spin polarization and spatial distribution models fail to accurately describe the polarization characteristics in coated cells. In this paper, based on the Langevin-Bloch equation, a dynamic model considering interaction effects between alkali metal atoms and the coating as well as between the pump light and the hyperfine levels of alkali metal atoms is proposed to accurately describe the spin polarization and spatial distribution in coated cells. To validate the proposed model, a series of experiments were carried out. The results demonstrate that coated cells can maintain high spin polarization and spatial homogeneity even under conditions of low pump intensity and high temperature, which are in good agreement with the simulations. This work provides a theoretical reference for the design of high-performance and low-power quantum sensors.

The cycling of volatiles through subduction zones fundamentally shapes Earth’s chemical evolution, yet how fluorine (F) and chlorine (Cl) are processed in the deep mantle remains enigmatic. Here, we use high-pressure experiments (5 to 11 gigapascals and 850° to 1200°C) on altered oceanic crust analogs to track deep halogen behavior. We show that phengite remains stable to 11 gigapascals and 1050°C, efficiently transporting F and Cl to ~330-kilometer depth. Upon breakdown or melting, phengite strongly fractionates these halogens: Cl is released into fluids or melts, while F is sequestered in residual phases such as KMgF3. The Cl-rich fluids produced (9.6 to 19.9 wt % Cl) closely match high-density fluid inclusions in diamonds, implicating them as key agents of cratonic metasomatism. Our findings establish phengite as a critical carrier mediating postarc fluxes of F (1.7 × 1012 to 2.6 × 1012 grams per year) and Cl (0.52 × 1012 to 1.1 × 1012 grams per year), providing a major pathway for replenishing deep mantle halogen reservoirs.

Cytotoxicity effects induced by silver and 4-chlorochalcone nanoparticles synthesized using Mentha spicata L. on breast cancer MDA-MB-231, MCF-7 cell lines and healthy MRC-5 fibroblasts

Zircon inclusions in garnet (ZiG) can be used as an elastic thermobarometer to estimate the pressure-temperature (P-T) conditions of geologic processes. Although this method is being increasingly applied as a thermometer to natural samples, experimental evaluation of ZiG is limited and has not been investigated at geologically relevant pressures. We present the first high-pressure assessment of the reliability of ZiG thermobarometry by crystallizing almandine with zircon inclusions in piston-cylinder experiments between 700−900 °C and 2.0−3.0 GPa. Zircons entrapped in experiments at >2.0 GPa yield residual inclusion pressures within 1σ of predicted values and yield entrapment temperatures within 17−30 °C of experimental T. Zircon inclusions in experiments performed at 2.0 GPa yield average inclusion pressures that are ∼0.09 GPa higher than predicted values and therefore yield entrapment temperatures 65−73 °C higher than the experimental T. Evaluation of inclusion pressure trends shows that ZiG host-inclusion systems did not undergo non-elastic deformation during experimental exhumation, confirming that ZiG elastic thermobarometry can accurately record P-T conditions of garnet crystallization so long as zircon inclusions do not go into tension post-entrapment. Our high-pressure experiments suggest that the ZiG host-inclusion system may be applicable to a variety of geologic settings and processes, such as subduction zone metamorphism, partial melting, and contact metamorphism.

With the expansion of global oil and gas resource exploration and development into deep and ultra deep layers, the efficient development of deep carbonate rock fracture cave reservoirs has become the key to ensuring energy security. However, this type of reservoir commonly faces high temperatures, high salinity, and extremely strong heterogeneity, leading to increasingly severe water content spikes caused by dominant water flow channels. Although the existing traditional inorganic plugging agent has good temperature resistance, it has the defects of great brittleness and easy cracking, while the organic polymer gel is prone to degradation failure under high temperature and high salt environments. In order to solve the above problems, a new biochar-enhanced inorganic composite gel system was constructed by using biochar prepared from agricultural and forestry waste pyrolysis as a functional enhancement component. Through rheological testing, high-temperature and high-pressure mechanical experiments, long-term thermal stability evaluation, and dynamic sealing experiments of fractured rock cores, the reinforcement and toughening laws and rheological control mechanisms of biochar on inorganic matrices were systematically studied. Research has found that a biochar content of 0.5 wt% can significantly improve the micro pore structure of the matrix. By utilizing its micro aggregate filling effect and interfacial chemical bonding, the compressive strength of the solidified body can be increased to over 2 MPa, and there is no significant decline in strength after aging at 130 °C for 30 days. More importantly, the unique “adsorption slow-release” mechanism of biochar effectively stabilizes the hydration reaction kinetics at high temperatures, extending the solidification time of the system to 15 h and solving the problem of flash condensation in deep well pumping. This system exhibits excellent shear thinning characteristics and crack sealing ability, and presents a unique “yield reconstruction” toughness sealing feature. This study elucidates the multidimensional strengthening mechanism of biochar in inorganic cementitious materials, providing technical reference for stable oil and water control in deep fractured reservoirs.

Mechanical properties of lead-free hybrid perovskites have attracted growing interest because of their significance in future eco-friendly optoelectronic applications. However, there are very limited studies about the intrinsic elastic properties and high-pressure structural evolution of hybrid perovskites, and the fundamental structure-mechanical property relationships are insufficiently understood. Here, we report the elastic behavior of a three-dimensional (3D) hybrid organic-inorganic perovskite, (DABCO)RbBr3 (DABCO = triethylenediammonium), and confirm the processability through processing with chiral metasurfaces and the generation of circular dichroism. Our in situ high-pressure synchrotron X-ray diffraction experiments demonstrate that this crystal does not start to amorphize until 2.3 GPa. Density functional theory calculations reveal that its E, G and v range between 20.73 and 27.93 GPa, 8.21 and 11.62 GPa and 0.18-0.39, respectively. Additionally, due to the low elastic moduli and polar crystal structure, we fabricate a device of (DABCO)RbBr3 composite film, which shows favorable performance for piezoelectric energy harvesting. This work utilizes (DABCO)RbBr3 to open up new avenues for applications in manufacturing and energy harvesting.

Studies of high-entropy materials contribute to various fields of science and reveal ever more exciting properties of applied interest. Here, we perform a study of the resistance of a Cantor alloy (CoCrFeNiMn) to hydrogen through high-pressure experiments at elevated temperatures by X-ray and neutron time-of-flight experiments and ab initio calculations. We report formation of an fcc hydride based on the Cantor alloy composition. We also provide its characterization, including an estimate of hydrogen content. These findings contribute to the growing body of knowledge on the complex chemistry of high-entropy alloys and high-entropy hydrides.

Air injection oil displacement is a highly promising enhanced oil recovery technology due to its wide gas source availability, low cost and strong reservoir adaptability. To enhance the application effectiveness of air injection for low-temperature oxidation (LTO) flooding in a specific light oil reservoir in China's Xinjiang oilfield, this study systematically investigates the static oxidation characteristics of crude oil and their influence on oil displacement performance. High-pressure static oxidation experiments and long-core physical simulation tests were conducted to examine the effects of oxidation time, water saturation, oxygen concentration, medium oil components (C7-C17), and reservoir minerals on the LTO behavior of crude oil. The oil displacement efficiency under different permeability conditions during air flooding was also analyzed. The results indicate that the LTO process exhibits stage-wise characteristics: in the initial stage, oxygen consumption is rapid, light and medium components decrease while heavy components increase, leading to higher viscosity and density of the crude oil. Reservoir conditions significantly influence oxidation pathways-high water saturation, low oxygen concentration, and high medium components inhibit oxidation, whereas reservoir cuttings promote cracking reactions due to their catalytic effect, resulting in oil lightening. Long-core flooding experiments further reveal that air flooding is more suitable for formations with relatively high permeability, which helps delay gas channeling, improve sweep efficiency, and thus achieve higher oil recovery. This research clarifies the intrinsic relationship between oxidation reactions and oil displacement performance during air injection, providing a theoretical basis for the application of air injection technology in light oil reservoirs.

CO2 geological sequestration in deep, unmineable coal seams is a key technology for carbon capture, utilization, and storage (CCUS). This study focuses on the No. 3 major high-rank coal reservoir in the southern Qinshui Basin, utilizing high-pressure and high-temperature CO2 isothermal adsorption experiments coupled with multiple adsorption models (Langmuir, BET, D-R) to establish a sequestration capacity calculation model. The study investigates CO2 sequestration mechanisms and evaluates potential and favorable zones for sequestration. The results show that CO2 sequestration mechanisms vary with temperature and pressure conditions. Specifically, adsorption dominates in the middle-deep subcritical zones but decreases with depth, while free-phase sequestration increases in the deep supercritical zone. Regarding model applicability, the BET model best fits supercritical CO2 adsorption, effectively capturing the sharp adsorption increase near the critical point. Quantitative assessments indicate that the optimal sequestration depth is 800-1100m, with a total sequestration potential of 575.5 Mt, 65.4% of which is in the deep supercritical zone. The supercritical zone's sequestration abundance reaches 956.1 × 103 t/km2, representing a 53.5% increase over the subcritical zone. Furthermore, adsorption and free-phase sequestration account for over 99% of the total potential, while dissolution and mineralization are negligible. Based on these evaluations, two deep coal reservoir units in the northern region are identified as optimal sequestration zones, coinciding with areas of high CBM potential, which could facilitate integrated CBM development and CO2 sequestration. This study provides a theoretical and methodological framework for evaluating CO2 sequestration potential and identifying favorable zones in deep coal reservoirs.

Experimental investigation of flow boiling CHF of heater rod with axially cosine-shaped power distribution under heaving conditions

Abstract The compressive behavior of Cr 2 S 3 in a quasi-hydrostatic environment was investigated by synchrotron x-ray diffraction using silicone oil as the pressure-transmitting medium in a diamond anvil cell. The maximum pressure was 34 GPa. We found that Cr 2 S 3 undergoes a structural phase transition at a pressure of 8.5 GPa and the bulk modulus before the phase transition was fitted to be 88 GPa, which corresponds to a bulk modulus of 67 GPa calculated by first-principles theory. In addition, we also investigated the electrical resistance of Cr 2 S 3 at different pressures and temperatures and found that the resistance decreases rapidly with increasing pressure or temperature and then remains almost unchanged with an increase in pressure or temperature. This indicates that Cr 2 S 3 undergoes a structural phase transition around 8 GPa. In order to accurately confirm the phase transition pressure, high-pressure Raman experiments were used. We found that the position of Raman peak 3 increases approximately linearly at low pressure and remains constant above 8 GPa, indicating that a structural phase transition occurs at 8 GPa. Finally, the deviatoric stress of Cr 2 S 3 at high pressures was investigated by the linewidth analysis method. The results show that the deviatoric stress increases approximately linearly at low pressures in the range of 2.8–6.2 GPa.

Recent geophysical observations indicate the presence of small-volume, carbonate-rich melts in Earth's deep interior. However, the mechanisms by which such minute melt fractions migrate through largely solid rocks and generate large-scale geophysical anomalies have remained unclear. Here, our high-pressure experiments demonstrate that, in the presence of H2O and NaCl, carbonate-rich melts act as super-spreaders, completely wetting and coating the surfaces of surrounding mantle minerals. This perfect wetting enables even trace amounts of melt (0.02 to 0.08 vol%) to form fully interconnected networks. Such connectivity facilitates efficient melt migration and chemical exchange, driving global material recycling between the surface and planetary interior.

The rheology of rocks is reviewed in the brittle–plastic transition (BPT), a key depth range in the continental crust and subduction plate boundaries where earthquakes, slow earthquakes, and stable sliding can all occur. Understanding the physical processes governing deformation in this zone is essential for linking laboratory observations to fault-slip behavior at the scale of plate boundaries. Quartz aggregates are a key material because quartz is abundant in the upper crust, as well as in pelitic and psammitic rocks in the subduction zone, and they serve as an analog for other rocks due to their well-studied deformation mechanisms. This focus is on fault zones within the BPT that contain abundant pore water, drawing primarily upon experimental studies on polycrystalline quartz. High-temperature, high-pressure deformation tests with controlled fluid content show that fluid-filled porosity markedly weakens quartz shear zones across the BPT. The rheology of these zones is controlled by pore fluid pressure, porosity, and fluid topology. Within the BPT, strain is partitioned between brittle and plastic deformation, but the degree of partitioning is complex and non-linear. The variability and complexity of deformation and fluid-filled porosity in the BPT may help explain the diverse spectrum of slip behaviors observed along plate boundaries.

Kinetic effects can be a critical factor in the study of high-pressure phase transitions. X-ray diffraction experiments on the timescales of the laboratory and the synchrotron can provide complementary results on such transformations.

Hydrogen hydrates (HH) are a unique class of materials composed of hydrogen molecules confined within crystalline water frameworks. Among their multiple phases, the filled ice structures, particularly the cubic C2 phase, exhibit exceptionally strong host-guest interactions due to ultra-short H2-H2O distances and a 1:1 stoichiometry leading to two interpenetrated identical diamond-like sublattices, one comprised of water molecules, the other of hydrogen molecules. At high pressures, nuclear-quantum effects involving both hydrogen molecules and the water lattice become dominant, giving rise to a dual-lattice quantum system. In this work, we explore the sequence of pressure- and temperature-driven phase transitions in HH, focusing on the interplay between molecular rotation, orientational ordering, lattice symmetry breaking, and hydrogen bond symmetrization. Using a combination of computational modeling based on classical and path-integral molecular dynamics, quantum embedding, and high pressure experiments, including Raman spectroscopy and synchrotron X-ray diffraction at low temperatures and high pressures, we identify signatures of quantum-induced ordering and structural transformations in the C2 phase. Our findings reveal that orientational ordering in HH occurs at much lower pressures than in solid hydrogen, by inducing structural changes in the water network and enhancing the coupling of water and hydrogen dynamics. This work provides insights into the quantum behavior of hydrogen under extreme mechanochemical confinement and establishes hydrogen-filled ices as a promising platform for the design of hydrogen-rich quantum materials.

The efficient extraction of natural gas from water-drive reservoirs is often hindered by premature water breakthrough and the consequent trapping of significant residual gas, which collectively result in suboptimal recovery and economic returns. Traditional production methods have proven inadequate in mitigating water influx and mobilizing this trapped gas, underscoring the need for advanced enhanced gas recovery (EGR) strategies. This research specifically examines the potential of nitrogen injection as a tertiary recovery technique in such reservoirs, with a focus on its mechanistic role and displacement efficiency. Utilizing high-pressure core flooding experiments and complementary numerical simulations, the process of nitrogen injection following water flooding was systematically investigated. Experimental findings at 30 MPa indicate that while water flooding left a substantial residual gas saturation of 28.1%, subsequent nitrogen injection reduced this to 20.8% at breakthrough and ultimately to 7.99%, achieving a final recovery of 88.9%. Simulation results further elucidate that in fractured systems, water preferentially channels through high-permeability fractures, while capillary imbibition leads to gas entrapment within the matrix. Nitrogen injection effectively targets and reduces this trapped gas saturation by 30–50%, demonstrating its efficacy as a viable EGR method. The study thus provides critical theoretical and practical insights for improving recovery in challenging water-drive gas reservoirs.

Summary The pore structure in shale oil reservoirs exerts a crucial control over hydrocarbon accumulation and migration. Taking medium-low maturity shale (R0 = 0.71–0.90%) from the Beibuwan Basin as the research object, we study thoroughly investigate the dynamic evolution of multiscale pore structures under high-temperature conditions (0–1,000°C) and their optimization mechanism for fluid percolation and transport efficiency. A comprehensive approach, combining gas adsorption experimental [low-temperature nitrogen (N2) adsorption and carbon dioxide (CO2) adsorption), scanning electron microscopy (SEM), X-ray diffraction (XRD), and high-pressure mercury injection experiments, along with quantitative indicators such as Shannon entropy and Lempel-Ziv complexity (LZC), was utilized to reveal the pore network reconstruction process from the perspectives of full pore size range and spatial heterogeneity. The results indicate that the evolution of shale pore structure exhibits two critical temperature thresholds: The first threshold (400–500°C) is where organic matter pyrolysis leads to a significant increase in pore volume and specific surface area, accompanied by an increase in Shannon entropy. However, the LZC value fluctuates minimally, and pores are mostly isolated and dispersed, resulting in limited improvement in connectivity. The second threshold (500–600°C) is where high-pressure mercury injection data show a sharp increase in permeability, and the LZC value reaches its peak, indicating that the pore-fracture network achieves efficient connectivity, forming a highly complex, interwoven multiscale percolation pathway. At higher temperatures (>600°C), mineral phase transformation further induces stress fractures, which synergistically interact with organic matter pyrolysis fractures (microcracks formed by the pyrolysis of organic matter and mineral phase transformation) to construct a pervasive permeable network within the matrix. This study reveals that the evolution of the shale pore network follows a dynamic process from “pore increment but limited connectivity” to “interconnected pore-fracture and efficient transport,” with the synergistic response between 500°C and 600°C being key to significant optimization of pore connectivity. This structural optimization enhances the pore-throat matching and effective fluid pathway development, providing a crucial micromechanistic basis for evaluating the fluid transport potential and enhanced hydrocarbon recovery in high-temperature shale reservoirs.