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Temperature Effects on the Mechanical Response and Failure Mechanism of Anisotropic Shale in Direct Shear

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SSRN 2024年

作者： Zhou, Pengli Xie, Heping Wang, Jun Zou, Bingbing Hu, Jianjun Li, Cunbao State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen University Shenzhen518060 China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green Energy College of Civil and Transportation Engineering Shenzhen University Shenzhen518060 China Shenzhen Key Laboratory of Deep Engineering Sciences and Green Energy College of Civil and Transportation Engineering Shenzhen University Shenzhen518060 China Institute of New Energy and Low‐Carbon Technology United Kingdom

The stimulation of shale reservoirs often involves marked shear failure, which plays a pivotal role in creating fracture networks and enhancing permeability for increased production. This study presents, for the first time, direct shear experiments conducted on shales at four different temperatures and seven bedding angles. By employing acoustic emission (AE) and digital image correlation (DIC) techniques, the evolution of damage and the mechanism of crack propagation under anisotropic direct shear at varying temperatures is revealed. The results indicate that the shear displacement and strength of shale increase with the temperature under different bedding angles. In addition, shale exhibits distinct brittle failure characteristics under various conditions during direct shear tests. The anisotropic shear failure types of shale under the influence of temperature include central shearing fracture, central shearing with secondary fracture, and deflected slip along the bedding. Moreover, the temperature effect enhances shear-induced crack propagation along bedding planes. Shear failure in shale is observed to primarily occur during higher loading stages, coinciding with a large amount of AE signals. Finally, the introduction of the anisotropy index and temperature sensitivity coefficient further elucidates the interaction mechanism between the temperature effects and anisotropy. This study provides crucial theoretical and experimental evidence regarding shear failure behavior under shale reservoir stimulation. © 2024, The Authors. All rights reserved.

关键词： Image correlation

巧妙的稀掺杂策略实现高性能GeTe热电材料

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Science Bulletin 2024年第8期69卷 1037-1049页

作者：钟锦璇杨晓玉吕途梁格格张胜楠张朝华敖伟琴刘福生南鹏飞葛炳辉胡利鹏 College of Materials Science and Engineering Shenzhen Key Laboratory of Special Functional MaterialsGuangdong Research Center for Interfacial Engineering of Functional MaterialsGuangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and UtilizationInstitute of Deep Earth Sciences and Green EnergyShenzhen UniversityShenzhen 518060China Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Superconducting Materials Research Center Northwest Institute for Nonferrous Metal ResearchXi’an 710016China

In thermoelectrics,doping is essential to augment the figure of *** strategy,predomina ntly heavy doping,aims to optimize carrier concentration and restrain lattice thermal ***,this tactic can severely hamper carrier transport due to pronounced point defect scattering,particularly in materials with inherently low carrier ***,dilute doping,although minimally affecting carrier mobility,frequently fails to optimize other vital thermoelectric ***,we present a more nuanced dilute doping strategy in GeTe,leveraging the multifaceted roles of small-size metal atoms.A mere 4%CuPbSbTe_(3)introduction into GeTe swiftly suppresses rhombohedral distortion and optimizes carrier concentration through the aid of Cu ***,the formation of multiscale microstructures,including zero-dimensional Cu interstitials,one-dimensional dislocations,two-dimensional planar defects,and three-dimensional nanoscale amorphous GeO_(2)and Cu_(2)GeTe_(3)precipitates,along with the ensuing lattice softening,contributes to an ultralow lattice thermal ***,dilute CuPbSbTe_(3)doping incurs only a marginal decrease in carrier *** trace Cd doping,employed to alleviate the bipolar effect and align the valence bands,yields an impressive figure-of-merit of 2.03 at 623 K in(Ge_(0.97)Cd_(0.03)Te)_(0.96)(CuPbSbTe_(3))_(0.04).This leads to a high energyconversion efficiency of 7.9%and a significant power density of 3.44 W cm^(-2)at a temperature difference of 500 *** results underscore the invaluable insights gained into the constructive role of nuanced dilute doping in the concurrent tuning of carrier and phonon transport in GeTe and other thermoelectric materials.

关键词： Thermoelectric GeTe Dilute doping Interstitial atoms Lattice softening

Critical Heat Flux(CHF)Correlations for Subcooled Water Flow Boiling at High Pressure and High Heat Flux

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Journal of Thermal Science 2021年第1期30卷 279-293页

作者： LIU Ping GUO Yusheng DING Wenlong TANG Mingyun SONG Yuntao PENG Xuebing JI Jiadong CHEN Qinghua MAO Xin State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China School of Mechanical Engineering Anhui University of Science and TechnologyHuainan 232001China Anhui Key Laboratory of Mine Intelligent Equipment and Technology Anhui University of Science and TechnologyHuainan 232001China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China School of Mining and Safety Engineering Anhui University of Science and TechnologyHuainan 232001China

The subcooled water flow boiling is beneficial for removing the high heat flux from the divertor in the fusion reactor,for which an accurate critical heat flux(CHF)correlation is *** to now,there are many CHF correlations mentioned for subcooled water flow boiling in the open ***,the CHF correlations’accuracies for the prediction of subcooled water flow boiling are not satisfactory at high heat flux and high pressure for reactor *** present paper compiled 1356 CHF experimental data points from 15 independent open literatures and evaluated 10 existing CHF correlations in subcooled water flow *** the evaluation,the W-2 CHF correlation performs best for the experimental CHF data in all existing critical heat flux ***,the predicted mean absolute error(MAE)of the W-2 correlation is not very ideal for all database and the MAE of the W-2 correlation is from 30%to 50%for some *** order to enhance the CHF prediction accuracy in subcooled water flow boiling at high heat flux and high pressure,the present paper developed a new CHF *** with other existing CHF correlations,the new CHF correlation greatly enhances the prediction accuracy over a broad range of pressures and heat fluxes which are desired in the cooling of high heat flux devices,such as those in the fusion reactor *** validation results show that the new correlation has a MAE of 10.05%and a root mean squared error(RMSE)of 16.61%,predicting 68.1%of the entire database within±10%and 81.5%within±15%.The MAE of the new CHF correlation is 7.4%less than that of the best existing one(W-2 correlation),further confirming its superior prediction accuracy and ***,the new CHF correlation works well not only for a uniform power profile but also for a non-uniform power profile in subcooled water flow boiling at high pressure and high heat flux.

关键词： reactor divertor correlations subcooled water flow boiling critical heat flux(CHF) high heat flux high pressure

A Shear Strength Criterion of Rock Joints Under Dynamic Normal Load

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SSRN 2024年

作者： Zhang, Qiang Gu, Qiuxin Li, Shuchen Wang, Hongying Han, Guilei School of Mechanics & Civil Engineering China University of Mining & Technology Xuzhou221116 China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and Technology Jiangsu Xuzhou221116 China School of Transportation Engineering Jiangsu Vocational Institute of Architectural Technology Xuzhou221116 China North China Engineering Investigation Institute Shijiazhuang050021 China

The shear strength of rock joints under dynamic normal load (DNL) conditions is quite different from that under constant normal loading (CNL) conditions. The commonly used shear strength criterion can’t predict the mechanical behavior of rock joints under DNL conditions. Therefore, a series of shear tests for rock joints under DNL condition were carried out. The evolutions of the shear strength parameters, including both cohesion and internal friction angle, with dynamic loading amplitude and frequency were investigated according to the experimental results. A shear strength criterion for rock joints under DNL condition was developed. The proposed model was verified by comparing its theoretically predicted shear strength with experimental results, both of which showed excellent agreement. Additionally, the strength criterion is utilized to predict the peak shear strength under CNL and new DNL conditions. These prediction results were further validated by experimental methods, which extend the applicability of the proposed strength criterion. The research results can provide theoretical guidance for the evaluation of rock formation engineering stability under dynamic load disturbance. © 2024, The Authors. All rights reserved.

关键词： Dynamic loads

Research on Active Temperature-Preserved Coring Method for Natural Gas Hydrate Based on Phase Change Materials

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SSRN 2024年

作者： Hu, Yunqi Xie, Heping Gao, Mingzhong Chen, Ling He, Zhiqiang Fu, Chenghang Xu, Meng Institute of New Energy and Low‐Carbon Technology United Kingdom State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Civil and Transportation Engineering Shenzhen University Shenzhen518060 China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and Hydropower Sichuan University Chengdu610065 China School of Mechanical Engineering Sichuan University Chengdu610065 China

Natural gas hydrates (NGH) as a clean energy source with vast reserves have a broad prospect. Coring is the most direct method 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 address this deficiency, this paper innovatively proposes an active temperature-preserved coring method for NGH based on phase change materials, designs and manufactures the active temperature-preserved corer (ATPC) and establishes an indoor experimental testing system for coring heat transfer. Referring to the in-situ environmental parameters of the NGH at the Haima cold seep, indoor experimental tests of the temperature-preserved performance of the corer were carried out, and a heat transfer model for the coring process was established. 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 °C, 20 °C, 25 °C, and 30 °C, the duration of low-temperature state for the NGH core is 53.85 min, 32.87 min, 20.32 min, and 11.83 min, respectively. These research findings provide a new perspective for NGH temperature-preserved coring and offer technical support for the exploration and developme

关键词： Temperature

Corrigendum to "Numerical analysis of the heat extraction performance of mine backfill heat exchanger based on phase change heat storage (PCHS-BFHE)" [Case Stud. Therm. Eng. 66 (2025) 105721]

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Case Studies in Thermal engineering 2025年 69卷

作者： Ning, Pai Ju, Feng Xu, Juan Xiao, Meng Wang, Tengfei Wang, Dong Si, Lu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and Technology Xuzhou 221116 China Ministry of Education Urumqi 830023 China School of Mining and Geological Engineering Xinjiang Institute of Engineering Urumqi Xinjiang 830023 China School of Mechanics and Civil Engineering China University of Mining and Technology Xuzhou 221116 China

Bridging Trajectory-Aware Evolutionary Graph Learning and Large Language Models for Enhancing Navigability in Social Internet of Things

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IEEE Internet of Things Journal 2025年

作者： Bi, Xin Han, Zhubin Yao, Xin Zhao, Xiangguo Wang, Yu-Ping Yuan, Ye State Key Laboratory of Intelligent Deep Metal Mining and Equipment China Northeastern University School of Computer Science and Engineering Shenyang110819 China Northeastern University College of Software Shenyang110819 China Beijing Institute of Technology School of Computer Science and Technology Beijing100091 China

Social Internet of Things (SIoT) has emerged as a novel paradigm that enhances IoT service capabilities by leveraging device-level social relationships. However, the explosive growth of heterogeneous devices, the dynamic mobile device trajectories, and complex spatiotemporal interaction patterns severely hinder SIoT network navigability. Particularly, the device mobility and contextual diversity pose significant challenges to social relation classification, a critical task for efficient routing and service discovery. Existing approaches, primarily designed for static or homogeneous networks, fail to adequately capture the evolving contextual dependencies and the spatiotemporal heterogeneity in SIoT. To address these challenges, we propose Trajectory-Aware Graph LLM (TAGLLM), a novel framework that enhances SIoT navigability through context-aware relation classification. TAGLLM introduces a multi-feature fusion trajectory evolutionary graph encoder to jointly model complex device attributes, social relations, and dynamic trajectories. Furthermore, a structural graph-text token alignment strategy is designed to exploit the generalization ability and contextual understanding capabilities of Large Language Models (LLMs), enabling more effective modeling of heterogeneous and dynamic SIoT scenarios. Extensive experiments on real-world SIoT datasets demonstrate that TAGLLM outperforms state-of-the-art baselines across multiple evaluation metrics, highlighting its potential to push the frontier of graph learning and LLM integration in SIoT applications. © 2014 IEEE.

关键词： Network theory (graphs)

Fabrication of the Designed Horn Antenna Using 3D Printing technology 15

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Fabrication of the Designed Horn Antenna Using 3D Printing T...

15th International Conference on Microwave and Millimeter Wave technology, ICMMT 2023

作者： Ma, Zhipeng Feng, Linping Zhou, Huan Hu, Wanyi Zhang, Yongliang Inner Mongolia University School of Electronic Information Engineering Inner Mongolia Hohhot010000 China Xian Jiaotong University Shaanxi Key Laboratory of Deep Space Exploration Intelligent Information Technology Xi'an710049 China Xian Jiaotong University School of Microelectronics Xi'an710049 China Inner Mongolia University School of Transportation Institute Inner Mongolia Hohhot010000 China

ISBN: (纸本)9798350338874

In this paper, a high-gain rectangular aperture horn antenna operating at 6-11 GHz is designed, processed using the SLM (Selective Laser Melting) 3D printing technology, and experimental results are measured. By comparison, the measured performance of the 3D printed antenna is found to be essentially consistent with the simulated performance, confirming the feasibility of using 3D printing technology to fabricate the horn antenna and potentially providing a new solution for the commercial application of horn antenna. © 2023 IEEE.

关键词： 3D printing

A Recovery Method of Large-Scale Isolated Stopes Supported by Pre-Stressed Expandable Props in deep Resource Mining: A Case Study

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SSRN 2023年

作者： Li, Kunmeng Li, Yuanhui Xiong, Zhipeng Li, Zhengrong Xiao, Guixuan Wang, Xin Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering Northeastern University Shenyang110819 China Institute of Deep Engineering and Intelligent Technology School of Resources and Civil Engineering Northeastern University Shenyang110819 China China-Canada Centre of Deep Mining Innovation Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering Northeastern University Shenyang110819 China

This study proposes a recovery method for large-scale isolated stopes supported by pre-stressed expandable props in deep resource mining. Using a large isolated stope of the Danyin gold mine in Dandong, China as the case study, the field-tested isolated stope stability is analysed by numerical simulation and field monitoring. The numerical simulation results show that, compared to unsupported, the vertical deformation could be effectively limited by the expandable props with a maximum value of 39 mm and plastic failure of the stope roof. Field industrial test shows that, the load on the expandable props and the roof deformation increase during the mining of the isolated stope. Especially when the top layer of the isolated stope is completely excavated to penetrate the entire goaf, the increment of the roof stress and deformation is significant. After the isolated stope is mined, the closer the location of the expandable prop is to the lower boundary of the isolated stope or the central axis of the entire goaf, the larger the load on the expandable prop will be;here, the maximum force on the expandable props is 1864 kN. The roof vertical and tangential deformations in the upper portion of the isolated stope are larger than those of the lower portion, resulting in dislocation and slippage of expandable props. The maximum roof vertical deformation of the isolated stope is about 21.5 mm, compared with the numerical simulation, the deviation is only 0.5 mm. The stress concentration area shifts from the isolated stope to the deeper portion of the orebody, inducing the roof collapse and the roadway barriers spalling. Although the adjacent goaf near the isolated stope collapses, the expandable props and the isolated stope are visually stable and safe except for the cracked pumice in the bolt nets. In the field of economic benefits, the large-scale isolated stope can achieve a profit of US$16.4 million. The conclusions of this study can provide a theoretical and technical ba

关键词： Roofs