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Evaluating the mechanical properties of anisotropic shale containing bedding and natural fractures with discrete element modeling

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International Journal of Coal Science & Technology 2022年第2期9卷 91-106页

作者： Yingjie Li Lihong Song Yuanjun Tang Jianping Zuo dongjie xue School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Natural fracture data from one of the Carboniferous shale masses in the eastern Qaidam Basin were used to establish a stochastic model of a discrete fracture network and to perform discrete element simulation research on the size efect and mechanical parameters of shale.Analytical solutions of fctitious joints in transversely isotropic media were derived,which made it possible for the proposed numerical model to simulate the bedding and natural fractures in shale masses.The results indicate that there are two main factors infuencing the representative elementary volume(REV)size of a shale mass.The frst and most decisive factor is the presence of natural fractures in the block itself.The second is the anisotropy ratio:the greater the anisotropy is,the larger the REV.The bedding angle has little infuence on the REV size,whereas it has a certain infuence on the mechanical parameters of the rock mass.When the bedding angle approaches the average orientation of the natural fractures,the mechanical parameters of the shale blocks decrease greatly.The REV representing the mechanical properties of the Carboniferous shale masses in the eastern Qaidam Basin were comprehensively identifed by considering the infuence of bedding and natural fractures.When the numerical model size is larger than the REV,the fractured rock mass discontinuities can be transformed into equivalent continuities,which provides a method for simulating shale with natural fractures and bedding to analyze the stability of a borehole wall in shale.

关键词： Shale Discrete fracture network Natural fracture Anisotropy Discrete element modeling

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Creep behavior and permeability evolution of coal pillar dam for underground water reservoir

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International Journal of Coal Science & Technology 2023年第1期10卷 136-141页

作者： Yulong Chen Xianjie Hao dongjie xue Zhe Li Xiaoran Ma State Key Laboratory of Water Resource Protection andUtilization in Coal Mining BeijingChina China University of Mining and Technology BeijingBeijingChina

Using goof as water storage space plays a vital role in the ecological environment and economic development of arid mining areas,while the rock strength and the stability of coal pillars in underground water reservoirs are closely related to creep process.In this work,triaxial creep-seepage tests were conducted for coal samples to develop new insights into the creep behavior and permeability evolution.The results showed that the creep deformation and permeability evolution of coal samples exhibit three stages,namely,the compaction hardening stage before the stress threshold,volumetric compaction stage,and volumetric dilatancy stage.The coal permeability decreases first and then increases with the creep strain and it is well correlated with the variation of volumetric strain.

关键词： Coal Creep Permeability Volumetric strain

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Cluster modeling of the short-range correlation of acoustically emitted scattering signals

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International Journal of Coal Science & Technology 2021年第4期8卷 575-589页

作者： dongjie xue Lele Lu Jie Zhou Lan Lu Yintong Liu School of Mechanics and Civil Engineering China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China Key Laboratory of Safety and High-efficiency Coal Mining Anhui University of Science and TechnologyHuainan 232001China

As a widely used measurement technique in rock mechanics,spatial correlation modeling of acoustic emission(AE)scattering signals is attracting increasing focus for describing mechanical behavior quantitatively.Unlike the statistical description of the spatial distribution of randomly generated AE signals,spatial correlation modeling is based mainly on short-range correlation considering the interrelationship of adjacent signals.As a new idea from percolation models,the covering strategy is used to build the most representative cube cluster,which corresponds to the critical scale at peak stress.Its modeling process of critical cube cluster depends strongly on the full connection of the main fracture network,and the corresponding cube for coverage is termed the critical cube.The criticality pertains to not only the transition of local-to-whole connection of the fracture network but also the increasing-to-decreasing transition of the deviatoric stress with an obvious stress drop in the brittle failure of granite.Determining a reasonable critical cube guarantees the best observation scale for investigating the failure process.Besides,the topological connection induces the geometric criticality of three descriptors,namely anisotropy,pore fraction,and specific surface area,which are evaluated separately and effectively.The results show that cluster modeling based on the critical cube is effective and has criticality in both topology and geometry,as well as the triaxial behavior.Furthermore,the critical cube length presents a high confidence probability of being correlated to the mineral particle size.Besides,its pore fraction of cube cluster is influenced strongly by the critical cube length and confining pressure.

关键词： Acoustic emission Spatial correlation modeling Cover strategy Criticality Critical cube Cluster modeling

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On the excavation-induced stress drop in damaged coal considering a coupled yield and failure criterion

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International Journal of Coal Science & Technology 2020年第1期7卷 58-67页

作者： dongjie xue Jie Zhou Yintong Liu Lie Gao School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China Key Laboratory of Safety and High-Efficiency Coal Mining Anhui University of Science and TechnologyHuainan 232001China

Investigating the stress drop of abutment pressure is the key to a deep quantitative analysis of the discontinuous stress redistribution under mining.In the present study,uniaxial and triaxial compression tests are carried out separately to determine the bulk and shear moduli,the cohesion,and the internal friction angle of the coal samples.By extending the meaning of Mohr’s circle referring to yield stress instead of the maximum principal stress,a yield line is introduced to illustrate the stress drop of Mohr’s circle referring to yield stress instead of the maximum principal stress at the elastoplastic boundary.Furthermore,a theoretical solution of the stress drop as a function of the damage is proposed to investigate how the abutment pressure differs considering the yield line and failure line.In addition,applying the stress drop at the yield line in non-pillar mining,top coal mining,and protective coal mining shows that the damage has a nonlinearly positive influence on the stress drop.The results shows that the bulk modulus and internal friction angle have a more sensitive influence on the stress drop than do the shear modulus and cohesion.Finally,the stress drop is divided into a discontinuous stress drop at the yield line and a structural stress drop at the failure line.The stress drop is effective in describing the discontinuous stress redistribution and shows a clear difference in the movement direction of Mohr’s circle considering the unloading pressure.

关键词： Stress drop Abutment pressure Mohr's circle Yield line Failure line

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Prediction of fracture and dilatancy in granite using acoustic emission signal cloud

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1059-1077页

作者： dongjie xue Lan Lu Lie Gao Lele Lu Cheng Chen School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400030China Key Laboratory of Safety and High-efficiency Coal Mining Anhui University of Science and TechnologyHuainan232001China

The invisibility of fracture network evolution in the rock under triaxial compression seriously restricts the correlation modeling between dilatancy behavior and fracture interconnectivity.The key to solving such a challenge is strongly dependent on the accurate modeling of the spatial correlation in fracture network,which could be indirectly re-constructed by the acoustic emission(AE)signal cloud.Considering the interaction of local fractures,a cube cluster approach is established to describe the spatial correlation.The evolutional cube clusters effectively present the geometric characteristics induced by the increasing dilatancy of fracture.Two descriptors(i.***.three-axis length sum and pore fraction)are introduced to correlate cluster model with dilatancy behavior.Most fitting results support the linear correlation between two descriptors and volumetric strain,which verifies the sensitiveness of the cube cluster model to dilatancy.More importantly,by the statistical analysis of cluster structure,the cluster model shows the potential of calculating fracture angle.Moreover,a comparison between dilatancybased damage and porosity-based damage is made not to prove the best but provide an AE-based prediction of local damage evolution.Finally,four classical models for calculating fracture angle are compared.The deviations prove the huge difficulty of describing the development of the fracture network uniquely dependent on a fracture angle.The proximity of measured angle and cluster-based angle supports the effectiveness of predication by the cube cluster approach.

关键词： Fracture network Acoustic emission(AE) Spatial correlation Dilatancy Damage Fracture angle

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燕麦β-葡聚糖的功效研究进展

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中国粮油学报 2024年第2期39卷 196-205页

作者：孟彦彤张东杰薛勇沈群中国农业大学食品科学与营养工程学院国家粮食产业(青稞深加工)技术创新中心国家果蔬加工工程技术研究中心中国农业大学北京100083 黑龙江八一农垦大学食品学院大庆163319

燕麦β-葡聚糖是主要存在于燕麦胚乳和糊粉层细胞壁中的非淀粉多糖,同时也是一种可溶性膳食纤维,是燕麦中的重要活性成分。本文对燕麦β-葡聚糖在减肥、调节血糖和血脂水平、改善心血管疾病、抗肿瘤以及调节免疫功能方面发挥作用的路径... 详细信息

燕麦β-葡聚糖是主要存在于燕麦胚乳和糊粉层细胞壁中的非淀粉多糖,同时也是一种可溶性膳食纤维,是燕麦中的重要活性成分。本文对燕麦β-葡聚糖在减肥、调节血糖和血脂水平、改善心血管疾病、抗肿瘤以及调节免疫功能方面发挥作用的路径及分子机制进行综述,以期为疾病的预防与治疗提供参考,为功能食品的开发和应用提供参考。

关键词：燕麦β-葡聚糖降糖降脂心血管疾病肠道菌群

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钢脚裂纹原因分析

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金属热处理 2024年第6期49卷 305-307页

作者：毕廉刘冬杰薛峰鞍钢集团北京研究院有限公司

通过金相显微镜、布氏硬度计和电感耦合等离子体发射光谱仪对钢脚裂纹进行分析。结果表明，钢脚非金属夹杂物较少，显微组织为调质态索氏体，与热处理工艺相符，化学成分满足GB/T 3077—2015要求。断口形貌呈细瓷状，未见疲劳开裂特点... 详细信息

通过金相显微镜、布氏硬度计和电感耦合等离子体发射光谱仪对钢脚裂纹进行分析。结果表明，钢脚非金属夹杂物较少，显微组织为调质态索氏体，与热处理工艺相符，化学成分满足GB/T 3077—2015要求。断口形貌呈细瓷状，未见疲劳开裂特点。整个裂纹两侧均未见脱碳、氧化、折叠形貌，为典型淬火裂纹形貌。开裂原因为大小工件同炉处理，造成小工件冷速过快，应力过大，进而形成开裂。

关键词：钢脚淬火裂纹原因分析

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Spatial correlation-based characterization of acoustic emission signal-cloud in a granite sample by a cube clustering approach

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International Journal of Mining Science and Technology 2021年第4期31卷 535-551页

作者： dongjie xue Zepeng Zhang Cheng Chen Jie Zhou Lan Lu Xiaotong Sun Yintong Liu School of Mechanics and Civil Engineering China University of Mining and Technology-BeijingBeijing 100083China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China State Key Laboratory of Coal Resource and Safe Mining China University of Mining and Technology-BeijingBeijing 100083China

To extract more in-depth information of acoustic emission(AE)signal-cloud in rock failure under triaxial compression,the spatial correlation of scattering AE events in a granite sample is effectively described by the cube-cluster model.First,the complete connection of the fracture network is regarded as a critical state.Then,according to the Hoshen-Kopelman(HK)algorithm,the real-time estimation of fracture con-nection is effectively made and a dichotomy between cube size and pore fraction is suggested to solve such a challenge of the one-to-one match between complete connection and cluster size.After,the 3D cube clusters are decomposed into orthogonal layer clusters,which are then transformed into the ellip-soid models.Correspondingly,the anisotropy evolution of fracture network could be visualized by three orthogonal ellipsoids and quantitatively described by aspect ratio.Besides,the other three quantities of centroid axis length,porosity,and fracture angle are analyzed to evaluate the evolution of cube cluster.The result shows the sample dilatancy is strongly correlated to four quantities of aspect ratio,centroid axis length,and porosity as well as fracture angle.Besides,the cube cluster model shows a potential pos-sibility to predict the evolution of fracture angle.So,the cube cluster model provides an in-depth view of spatial correlation to describe the AE signal-cloud.

关键词： Acoustic emission Triaxial compression Fracture connection Spatial correlation Cube cluster model Dilatancy

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杂豆中抗营养因子的检测及其消除方法研究进展

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食品工业科技 2024年第7期45卷 335-343页

作者：薛璐璐阮长青张东杰李志江黑龙江八一农垦大学食品学院黑龙江省农产品加工与质量安全重点实验室国家杂粮工程技术中心黑龙江大庆163319

杂豆中除了含有丰富的营养及生物活性物质外,还含有植酸、皂苷、胰蛋白酶抑制剂、凝集素等抗营养因子,这些物质种类多、检测过程复杂、检测能力各不相同。采用一定的处理方法不仅可以破坏它们的结构、降低含量,而且能在加工过程中最大... 详细信息

杂豆中除了含有丰富的营养及生物活性物质外,还含有植酸、皂苷、胰蛋白酶抑制剂、凝集素等抗营养因子,这些物质种类多、检测过程复杂、检测能力各不相同。采用一定的处理方法不仅可以破坏它们的结构、降低含量,而且能在加工过程中最大程度保留杂豆中的营养成分。本文详细评价了抗营养因子的检测方法,分析、比较了多种检测方法的优缺点、适用范围、灵敏度,并介绍了以热处理为主的几种常见抗营养因子消除方法的原理、流程、抑制效果、优缺点。旨在为杂豆中抗营养因子的分析方法选择、改进及其控制提供一些参考。

关键词：杂豆抗营养因子热处理检测方法食品安全

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A Self-Powered Optogenetic System for Implantable Blood Glucose Control

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Research 2022年第4期2022卷 295-307页

作者： Zhuo Liu Yang Zhou xuecheng Qu Lingling Xu Yang Zou Yizhu Shan Jiawei Shao Chan Wang Ying Liu Jiangtao xue dongjie Jiang Yubo Fan Zhou Li Haifeng Ye Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education Beijing Advanced Innovation Centre for Biomedical EngineeringSchool of Biological Science and Medical EngineeringSchool of Engineering MedicineBeihang UniversityBeijing 100191China CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and Sensor Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 101400China Shanghai Frontiers Science Center of Genome Editing and Cell Therapy Biomedical Synthetic Biology Research CenterShanghai Key Laboratory of Regulatory BiologyInstitute of Biomedical Sciences and School of Life SciencesEast China Normal UniversityDongchuan Road 500Shanghai 200241China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Center of Nanoenergy Research School of Physical Science and TechnologyGuangxi UniversityNanning 53004China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Chongqing Key Laboratory of Precision Optics Chongqing Institute of East China Normal UniversityChongqing 401120China

Diabetes treatment and rehabilitation are usually a lifetime process.Optogenetic engineered designer cell-therapy holds great promise in regulating blood glucose homeostasis.However,portable,sustainable,and long-term energy supplementation has previously presented a challenge for the use of optogenetic stimulation in vivo.Herein,we_purpose a self-powered optogenetic system(SOS)for implantable blood glucose control.The SOS consists of a biocompatible far-red light(FRL)source,FRL-triggered transgene-expressing cells,a power management unit,and a flexible implantable piezoelectric nanogenerator(i-PENG)to supply long-term energy by converting biomechanical energy into electricity.Our results show that this system can harvest energy from body movement and power the FRL source,which then significantly enhanced production of a short variant of human glucagon-like peptide 1(shGLP-1)in vitro and in vivo.Indeed,diabetic mice equipped with the SOS showed rapid restoration of blood glucose homeostasis,improved glucose,and insulin tolerance.Our results suggest that the SOs is sufficiently effective in self-powering the modulation of therapeutic outputs to control glucose homeostasis and,furthermore,present a new strategy for providing energy in optogenetic-based cell therapy.

关键词： homeostasis Blood furthermore

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