Sichuan University: Chinese Research Output & Key Publications | SinoTechIntel

Int. Journal of Mining Science and Technology (采矿与安全工程)•2026

Consolidation-Sealing of In-Situ Internal Stress in Deep Rocks: Device Development and Mechanical Behavior Characterization

Authors: Mingzhong Gao, Chuo Zhang, Fei Li, Bengao Yang, Jing Xie, Zundong Yang, Kunchen He

Addressing the scientific problem of unclear understanding of in-situ internal stress and its evolution in deep rock masses, a scientific definition and implementation path for the concept of in-situ internal stress consolidation-sealing in deep rock masses are proposed, and a set of in-situ internal stress consolidation-sealing test device for deep rock masses has been independently developed. The device consists of a material consolidation cultivation module, an in-situ internal stress environment simulation module, and a multi-source information capture module. And the three mechanical tests of internal stress preservation, internal stress release and conventional were carried out with the device. The evolution law of the deformation parameters in the internal stress consolidation-sealing stage was studied, and the difference characteristics of the deformation parameters before and after the internal stress releasing were compared and analyzed. The results show that the internal stress consolidation-sealing significantly affects the mechanical properties of the simulated rock material, while the internal stress release leads to the damage of the material properties, suggesting that the presence and influence of internal stress should not be overlooked. This study could provide a new research direction and scientific devices for the expansion and deepening of the field of deep in-situ rock mechanics.

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Journal of Central South University•2026

The influence of microwave irradiation on thermal properties and fracturing mechanism of basalt in rock excavation

Authors: TANG Rui-feng, YANG Ben-gao, XIE Jing, YANG Zhu, YANG Zun-dong, BAI Yan-bo, GAO Ming-zhong

Microwave fracturing is a promising technique for facilitating the efficient exploitation of deep earth resources while reducing energy consumption and cutter wear during mechanical excavation. In this study, the thermal properties of basalt under six power levels are investigated and the mechanism of microwave fracturing is elucidated through real-time monitoring and microstructural analysis. The results show that the failure modes of basalt can be categorized into high-temperature melting failure (>300 ℃) and low-temperature burst failure (<200 ℃). High-power microwave irradiation not only altered the failure mode but also modified the relationship between temperature rise and time. The temperature distribution exhibits a wave pattern, making it more prone to inducing transverse tensile cracks. Dehydration of basalt is triggered when the temperature exceeds 200 ℃, which subsequently promotes the initiation of macroscopic cracks. Microscopically, microwave fracturing is mainly driven by thermal stresses, while steam pressure, especially under high-power conditions, plays a dominant role in the fracturing process. These results are anticipated to provide necessary theoretical and technical support for the efficient exploitation of deep earth resources.

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Journal of Central South University•2026

Heating and fracture spatiotemporal evolution characteristics of key granite minerals under microwave irradiation

Authors: BAI Yan-bo, YANG Ben-gao, WANG Jing-yu, XIE Jing, TANG Rui-feng, GAO Ming-zhong, YUAN Liang

Microwave fracturing offers significant potential for efficient hard rock fragmentation. This study investigates real-time heating and fracture characteristics of ten granitoid minerals under 2 kW microwave irradiation for 3 min. Chlorite, amphibole, and altered plagioclase were identified as highly microwave-sensitive, exhibiting high mass and P-wave velocity decay, rapid heating rates (>2.5 ℃/s) and violent rupture. Mineral surface temperature non-uniformity, quantified by the coefficient of variation (VT), evolved through distinct increasing, decreasing, and stabilizing phases, reflecting shifts in dominance between heat accumulation and transfer. Temperature gradients revealed the spatial relationship between hotspots and rupture points, with shallow melting influencing surface temperature distribution. Undamaged minerals exhibited significant temperature gradient spatiotemporal variability but ultimately stabilizing. These results enable prediction of microwave heating behavior in hard rocks containing analogous minerals and enhance our understanding of microwave-induced weakening mechanisms.

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Int. Journal of Mining Science and Technology (采矿与安全工程)•2025

Key techniques for precise measuring gas content in deep coal mine: In-situ pressure- and gas-preserved coring

Authors: Ju Li, Jianan Li, Tianyu Wang, Guikang Liu, Zhiqiang He, Cong Li, Heping Xie

Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks. However, existing sampling technologies face challenges in maintaining the integrity of gas content within samples and are often constrained by estimation errors inherent in empirical formulas, which results in inaccurate gas content measurements. This study introduces a lightweight, in-situ pressure- and gas-preserved corer designed to collect coal samples under the pressure conditions at the sampling point, effectively preventing gas loss during transfer and significantly improving measurement accuracy. Additionally, a gas migration model for deep coal mines was developed to elucidate gas migration characteristics under pressure-preserved coring conditions. The model offers valuable insights for optimizing coring parameters, demonstrating that both minimizing the coring hole diameter and reducing the pressure difference between the coring-point pressure and the original pore pressure can effectively improve the precision of gas content measurements. Coring tests conducted at an experimental base validated the performance of the corer and its effectiveness in sample collection. Furthermore, successful horizontal coring tests conducted in an underground coal mine roadway demonstrated that the measured gas content using pressure-preserved coring was 34% higher than that obtained through open sampling methods.

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Int. Journal of Mining Science and Technology (采矿与安全工程)•2025

Design and Mechanical Optimization of Multidirectional Pressure-Preserved Coring System for Deep-Earth Resource Exploration

Authors: Guikang Liu, Yachen Xie, Cong Li

Pressure-preserved coring technologies are critical for deep-earth resource exploration but are constrained by the inability to achieve multidirectional coring, restricting exploration range while escalating costs and environmental impacts. We developed a multidirectional pressure-preserved coring system based on magnetic control for deep-earth environments up to 5000 m. The system integrates a magnetically controlled method and key pressure-preserved components to ensure precise self-triggering and self-sealing. It is supported by geometric control equations for optimizing structural stability. Their structure was verified and optimized through theoretical and numerical calculations to meet design objectives. To clarify the self-triggering mechanism in complex environments, a dynamic interference model was established, verifying stability during multidirectional coring. The prototype was fabricated, and functional tests confirmed that it met its design objectives. In a 300-meter-deep test inclined well, 10 coring operations were completed with a 100% pressure-preserved success rate, confirming the accuracy of the dynamic interference model analysis. Field trials in a 1970-meter-deep inclined petroleum well, representative of complex environments, demonstrated an in-situ pressure preservation efficiency of 92.18% at 22 MPa. This system innovatively expands the application scope of pressure-preserved coring, providing technical support for efficient and sustainable deep resources exploration and mining.

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Int. Journal of Mining Science and Technology (采矿与安全工程)•2025

A PCM-based active temperature-preserved coring method for deep sea natural gas hydrate

Authors: Han Wu, Yunqi Hu, Chenghang Fu, Ling Chen, Zhiqiang He, Meng Xu, Heping Xie

Natural gas hydrate (NGH) has a bright future as a clean energy source with huge reserves. Coring is one of the most direct methods for NGH exploration and research. Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources. However, most existing NGH coring techniques cannot preserve the in-situ temperature of NGH, leading to distortion of the physical properties of the obtained core, which makes it difficult to effectively guide NGH exploration and development. To overcome this limitation, this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials (PCM). An active temperature-preserved corer (ATPC) is designed and developed, and an indoor experimental system is established to investigate the heat transfer during the coring process. Based on the experimental results under different environment temperatures, a heat transfer model for the entire ATPC coring process has been established. The indoor experimental results are consistent with the theoretical predictions of the heat transfer model, confirming its validity. This model has reconstructed the temperature changes of the NGH core during the coring process, demonstrating that compared to the traditional coring method with only passive temperature-preserved measures, ATPC can effectively reduce the core temperature by more than 5.25 °C. With ATPC, at environment temperatures of 15, 20, 25, and 30 °C, the duration of low-temperature state for the NGH core is 53.85, 32.87, 20.32, and 11.83 min, respectively. These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.

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Int. Journal of Mining Science and Technology (采矿与安全工程)•2025

In-situ temperature- and pressure-preserved sampler for marine natural gas hydrates: Principles, techniques, and field application

Authors: Chenghang Fu, Le Zhao, Ling Chen, Guikang Liu, Han Wu, Mingzhu Qi, Ming Zhang, Heping Xie

Marine gas hydrates are highly sensitive to temperature and pressure fluctuations, and deviations from in-situ conditions may cause irreversible changes in phase state, microstructure, and mechanical properties. However, conventional samplers often fail to maintain sealing and thermal stability, resulting in low sampling success rates. To address these challenges, an in-situ temperature- and pressure-preserved sampler for marine applications has been developed. The experimental results indicate that the self-developed magnetically controlled pressure-preserved controller reliably achieves autonomous triggering and self-sealing, provides an initial sealing force of 83 N, and is capable of maintaining pressures up to 40 MPa. Additionally, a custom-designed intelligent temperature control chip and high-precision sensors were integrated into the sampler. Through the design of an optimized heat transfer structure, a temperature-preserved system was developed, achieving no more than a 0.3 °C rise in temperature within 2 h. The performance evaluation and sampling operations of the sampler were conducted at the Haima Cold Seep in the South China Sea, resulting in the successful recovery of hydrate maintained under in-situ pressure of 13.8 MPa and a temperature of 6.5 °C. This advancement enables the acquisition of high-fidelity hydrate samples, providing critical support for the safe exploitation and scientific analysis of marine gas hydrate resources.

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China Foundry•2025

Microstructural evolution and mechanical properties of Ti43Al alloy by directional annealing

Authors: Li Zhou, Jie-ren Yang, Yun-lu Ma, Ze-dong Liu, Rui-run Chen

Abstract: The directional annealing technique is widely used to prepare columnar grains or single crystals. To investigate the effect of hot zone temperature and temperature gradient on the growth of columnar crystals, Ti43Al alloys were heat treated by the directional annealing technique and their mechanical properties were tested. The results show that columnar grains with a maximum size of 22.29 mm can be obtained at a hot zone temperature of 1,350 °C and a temperature gradient of 8 K·mm-1. During the directional annealing process, Ti43Al alloys are heated to α single-phase domain to start the phase transformation. Columnar grains with a microstructure of fully lamellar colonies are obtained at different hot zone temperatures and temperature gradients. The distribution of the orientation difference for the α2 phase was found to be more random, suggesting that the growth of the columnar crystals may be stochastic in nature. Tensile testing results show that the strength and elongation of directional annealed Ti43Al alloy at 1,400 °C-8 K·mm-1 are 411.23 MPa and 2.29%, and the remaining directional annealed alloys show almost plasticity.

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Nano-Micro Letters•2025

Critical Bimetallic Phosphide Layer Enables Fast Electron Transfer and Extra Energy Supply for Flexible Quasi-Solid-State Zinc Batteries

Authors: Leixin Wu, Linfeng Lv, Yibo Xiong, Wenwu Wang, Xiaoqiao Liao, Xiyao Huang, Ruiqi Song, Zhe Zhu, Yixue Duan, Lei Wang, Zeyu Ma, Jiangwang Wang, Fazal ul Nisa, Kai Yang, Muhammad Tahir, Longbing Qu, Wenlong Cai, Liang He

Nickel-based cathodes in aqueous nickel-zinc batteries typically suffer from sluggish reaction kinetics and limited energy density. In situ introduction of metal phosphides and rational construction of heterostructures can effectively promote electron/ion transport. However, the complex evolution of phosphidation and intractable phosphidizing degree greatly affect the composition of active phase, active sites, charge transfer rate, and ion adsorption strength of cathodes. Herein, the critical bimetallic phosphide layer (CBPL) is constructed on the NiCo-layered double hydroxide (NiCo-LDH) skeleton by a controllable anion-exchange strategy, yielding a novel nanohybrid cathode (NiCo-P1.0, 1.0 representing the mass ratio of Na2H2PO2 to NiCo-LDH). The high-conductivity CBPL with the inner NiCo-LDH forms extensive heterostructures, effectively regulating the electronic structure via charge transfer, thereby improving electrical conductivity. Remarkably, the CBPL exhibits unexpected electrochemical activity and synergizes with NiCo-LDH for electrode reactions, ultimately delivering extra energy. Benefiting from the bifunctional CBPL, NiCo-P1.0 delivers an optimal capacity of 286.64 mAh g−1 at 1C (1C = 289 mAh g−1) and superb rate performance (a capacity retention of 72.22% at 40C). The assembled NiCo-P1.0//Zn battery achieves ultrahigh energy/power density (503.62 Wh kg−1/18.62 kW kg−1, based on the mass loading of active material on the cathode), and the flexible quasi-solid-state pouch cell validates its practicality. This work demonstrates the superiority of bifunctional CBPL for surface modification, providing an effective and scalable compositing strategy in achieving high-performance cathodes for aqueous batteries.

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Nano-Micro Letters•2025

Ultrahigh Energy and Power Density in Ni–Zn Aqueous Battery via Superoxide-Activated Three-Electron Transfer

Authors: Yixue Duan, Bolong Li, Kai Yang, Zheng Gong, Xuqiao Peng, Liang He, Derek Ho

Aqueous Ni–Zn microbatteries are safe, reliable and inexpensive but notoriously suffer from inadequate energy and power densities. Herein, we present a novel mechanism of superoxide-activated Ni substrate that realizes the redox reaction featuring three-electron transfers (Ni ↔ Ni3+). The superoxide activates the direct redox reaction between Ni substrate and KNiO2 by lowering the reaction Gibbs free energy, supported by in-situ Raman and density functional theory simulations. The prepared chronopotentiostatic superoxidation-activated Ni (CPS-Ni) electrodes exhibit an ultrahigh capacity of 3.21 mAh cm−2 at the current density of 5 mA cm−2, nearly 8 times that of traditional one-electron processes electrodes. Even under the ultrahigh 200 mA cm−2 current density, the CPS-Ni electrodes show 86.4% capacity retention with a Columbic efficiency of 99.2% after 10,000 cycles. The CPS-Ni||Zn microbattery achieves an exceptional energy density of 6.88 mWh cm−2 and power density of 339.56 mW cm−2. Device demonstration shows that the power source can continuously operate for more than 7 days in powering the sensing and computation intensive practical application of photoplethysmographic waveform monitoring. This work paves the way to the development of multi-electron transfer mechanisms for advanced aqueous Ni–Zn batteries with high capacity and long lifetime.

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Chinese Journal of Mechanical Engineering•2025

Human-centric Product Conceptual Design Model and Its Feedback-based Co-evolution Method

Authors: Bing Lai, Xin Guo, Wu Zhao, Jun Li, Hao Xue, Kai Zhang

In the context of Industry 5.0, more emphasis is placed on human-centric smart manufacturing patterns. Product design is a vital phase of smart manufacturing, involving user engagement is an essential factor in enhancing design quality and fostering innovation. With user involvement in-depth, dynamically changing user requirements and feedback bring new problems to the design process, and the traditional linear solving process cannot perceive such variations timely, which causes hysteresis in the solution. The design solution’s hysteresis affects the consensus achievement process between the designer and user, further prolonging the iteration cycle. To address this issue, a human-centric product conceptual design model is proposed for the timely translation of such variations into design solutions. In this model, design problems are formed by centering on user requirements, designer and user collaboratively solve the problems to form design solutions. Through a cycle of problem-driven, knowledge-supported, and solution evaluation, new problems are solved promptly to achieve progressive solution convergence, which clarifies the iterative evolution process and improves iterative efficiency. To verify the effectiveness of the model, a natural gas well foaming agent automatic filling device design is presented.

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Journal of Central South University•2025

Mechanism of confining pressure-induced failure mode transition in granite: Implications from acoustic emission and numerical simulation

Authors: XU Meng-ling, XU Nu-wen, LI Zhuang, HE Yi-fan, SUN Ling-feng, JIA Nai-ze

To elucidate the influence of confining pressure on microcrack evolution and macroscopic failure mechanisms in granite, a multi-perspective approach was adopted. This approach combined triaxial compression tests, acoustic emission (AE) monitoring, and PFC simulations. The results show that: 1) Confining pressure exhibits a pronounced linear correlation with both yield strength and compressive strength. The enhancement of confining pressure significantly improves the deformability of granite and promotes a progressive shift in failure mechanism from brittle rupture to ductile deformation; 2) Increasing confining pressure elevates the stress threshold for microcrack initiation and suppresses crack propagation. As a result, the proportion of shear cracks increases (based on AE analysis) from 18.71% to 61.2%, marking a transition in the dominant failure mode from tensile to shear; 3) Confining pressure facilitates the development of grain boundary shear cracks (GBSCs), establishing the primary damage pathways. In addition, local stress concentrations under high confinement conditions trigger intragranular cracking. This highlights the regulatory effect of confining pressure on microcrack evolution.

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