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Investigation of a non-explosive directional roof cutting technology for self-formed roadway

International Journal of Mining Science and Technology 2022年第5期32卷 997-1008页

作者： Quan Zhang Manchao He Jiong Wang Shan Guo chun zhu Zhigang Tao Chao Wang School of Mines China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Geomechanics&Deep Underground Engineering China University of Mining and Technology-BeijingBeijing 100083China School of Earth Sciences and Engineering Hohai UniversityNanjing 210098China

Traditional explosives have characteristics of high risk,large vibration,and poor directional fracturing.Consequently,an instantaneous expander with a single crack surface(IESCS),which is a novel nonexplosive directional rock-breaking technique,has been developed.The directional roof-cutting mechanism of the IESCS method,driven by high-pressure gas,was theoretically analyzed.Laboratory experiments and numerical simulations proved the directional slitting effect of the IESCS method to be excellent.Compared with shaped-charge blasting,the charge of IESCS was reduced by 8.9%,but the crack rate increased by 9%in field tests.After IESCS pre-splitting,the roof directionally collapsed along the cutting line,and the gangue filled the goaf.Moreover,the directional roof cutting by the IESCS could decrease roadway stress.The average pressure of hydraulic supports on the cutting side of the roof was 31%lower than that on the non-cutting side of the roof after pre-splitting.After the self-formed roadway constructed by the IESCS was stabilized,the final relative displacement of the roof and floor was 157.3 mm,meeting the required standard of the next working face.Thus,the IESCS was effectively applied to directional roof pre-splitting.The results demonstrate the promising potential of IESCS in the mining and geotechnical fields.

关键词： Instantaneous expander with a single crack surface Non-explosive Directional roof cutting Self-formed roadways Pillarless mining

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Experimental study on the shear performance of quasi-NPR steel bolted rock joints

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第2期15卷 350-362页

作者： Manchao He Shulin Ren Haotian Xu Senlin Luo Zhigang Tao chun zhu State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China

Quasi-NPR(negative Poisson’s ratio)steel is a new type of super bolt material with high strength,high ductility,and a micro-negative Poisson’s effect.This material overcomes the contrasting characteristics of the high strength and high ductility of steel and it has significant energy-absorbing characteristics,which is of high value in deep rock and soil support engineering.However,research on the shear resistance of quasi-NPR steel has not been carried out.To study the shear performance of quasi-NPR steel bolted rock joints,indoor shear tests of bolted rock joints under different normal stress conditions were carried out.Q235 steel and#45 steel,two representative ordinary bolt steels,were set up as a control group for comparative tests to compare and analyze the shear strength,deformation and instability mode,shear energy absorption characteristics,and bolting contribution of different types of bolts.The results show that the jointed rock masses without bolt reinforcement undergo brittle failure under shear load,while the bolted jointed rock masses show obvious ductile failure characteristics.The shear deformation ca-pacity of quasi-NPR steel is more than 3.5 times that of Q235 steel and#45 steel.No fracture occurs in the quasi-NPR steel during large shear deformation and it can provide stable shear resistance.However,the other two types of control bolts become fractured under the same conditions.Quasi-NPR steel has significant energy-absorbing characteristics under shear load and has obvious advantages in terms of absorbing the energy released by shear deformation of jointed rock masses as compared with ordinary steel.In particular,the shear force plays a major role in resisting the shear deformation of Q235 steel and#45 steel,therefore,fracture failure occurs under small bolt deformation.However,the axial force of quasi-NPR steel can be fully exerted when resisting joint shear deformation;the steel itself does not break when large shear deformation occurs,and the supporting effect of the jointed rock mass is ef

关键词： Energy absorption bolt Quasi-NPR(Negative Poisson’s ratio)steel Bolted rock joints Shear test Shear performance

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Fracture of two three-dimensional parallel internal cracks in brittle solid under ultrasonic fracturing

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 757-769页

作者： Haijun Wang Hanzhang Li Lei Tang Xuhua Ren Qingxiang Meng chun zhu State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing210029China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China

Similar to hydraulic fracturing(HF), the coalescence and fracture of cracks are induced within a rock under the action of an ultrasonic field, known as ultrasonic fracturing(UF). Investigating UF is important in both hard rock drilling and oil and gas recovery. A three-dimensional internal laser-engraved crack(3D-ILC) method was introduced to prefabricate two parallel internal cracks within the samples without any damage to the surface. The samples were subjected to UF. The mechanism of UF was elucidated by analyzing the characteristics of fracture surfaces. The crack propagation path under different ultrasonic parameters was obtained by numerical simulation based on the Paris fatigue model and compared to the experimental results of UF. The results show that the 3D-ILC method is a powerful tool for UF research.Under the action of an ultrasonic field, the fracture surface shows the characteristics of beach marks and contains powder locally, indicating that the UF mechanism includes high-cycle fatigue fracture, shear and friction, and temperature load. The two internal cracks become close under UF. The numerical result obtained by the Paris fatigue model also shows the attraction of the two cracks, consistent with the test results. The 3D-ILC method provides a new tool for the experimental study of UF. Compared to the conventional numerical methods based on the analysis of stress-strain and plastic zone, numerical simulation can be a good alternative method to obtain the crack path under UF.

关键词： Three-dimensional internal laser-engraved crack(3D-ILC) Interaction of cracks Ultrasonic fatigue Penny-shaped crack Fracture mechanics High-cycle fatigue

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用于重建物理和虚拟抓取的可重构数据手套

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Engineering 2024年第1期32卷 202-216页

作者： Hangxin Liu Zeyu Zhang Ziyuan Jiao Zhenliang Zhang Minchen Li Chenfanfu Jiang Yixin zhu Song-chun zhu National Key Laboratory of General Artificial Intelligence Beijing Institute for General Artificial Intelligence(BIGAI)Beijing 100080China Center for Vision CognitionLearning and AutonomyUniversity of CaliforniaLos AngelesCA 90095USA Multi-Physics Lagrangian-Eulerian Simulations Laboratory Department of MathematicsUniversity of CaliforniaLos AngelesCA 90095USA Institute for Artificial Intelligence Peking UniversityBeijing 100871China Department of Automation Tsinghua UniversityBeijing 100084China

In this work,we present a reconfigurable data glove design to capture different modes of human hand-object interactions,which are critical in training embodied artificial intelligence(AI)agents for fine manipulation tasks.To achieve various downstream tasks with distinct features,our reconfigurable data glove operates in three modes sharing a unified backbone design that reconstructs hand gestures in real time.In the tactile-sensing mode,the glove system aggregates manipulation force via customized force sensors made from a soft and thin piezoresistive material;this design minimizes interference during complex hand movements.The virtual reality(VR)mode enables real-time interaction in a physically plausible fashion:A caging-based approach is devised to determine stable grasps by detecting collision events.Leveraging a state-of-the-art finite element method,the simulation mode collects data on fine-grained four-dimensionalmanipulation events comprising hand and object motions in three-dimensional space and how the object's physical properties(e.g.,stress and energy)change in accordance with manipulation over time.Notably,the glove system presented here is the first to use high-fidelity simulation to investigate the unobservable physical and causal factors behind manipulation actions.In a series of experiments,we characterize our data glove in terms of individual sensors and the overall system.More specifically,we evaluate the system's three modes by①recording hand gestures and associated forces,②improving manipulation fluency in VR,and③producing realistic simulation effects of various tool uses,respectively.Based on these three modes,our reconfigurable data glove collects and reconstructs fine-grained human grasp data in both physical and virtual environments,thereby opening up new avenues for the learning of manipulation skills for embodied AI agents.

关键词： Data glove Tactile sensing Virtual reality Physics-based simulation

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Ultrastable nickel single-atom catalysts with high activity and selectivity for electrocatalytic CO_(2)methanation

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Nano Research 2023年第7期16卷 8987-8995页

作者： Ling-Chan Tian Jin-Nian Hu Yang Meng Jin-Xia Liang chun zhu Jun Li School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua UniversityBeijing 100084China

Electrochemical conversion of CO_(2)into valuable hydrocarbon fuel is one of the key steps in solving carbon emission and energy issue.Herein,we report a non-noble metal catalyst,nickel single-atom catalyst(SAC)of Ni_(1)/UiO-66-NH_(2),with high stability and selectivity for electrochemical reduction of CO_(2)to CH_(4).Based on ab initio molecular dynamics(AIMD)simulations,the CO_(2)molecule is at first reduced into CO_(2)-when stably adsorbed on a Ni single atom with the bidentate coordination mode.To evaluate its activity and selectivity for electrocatalytic reduction of CO_(2)to different products(HCOOH,CO,CH3OH,and CH_(4))on Ni_(1)/UiO-66-NH_(2),we have used density functional theory(DFT)to study different reaction pathways.The results show that CH_(4) is generated preferentially on Ni_(1)/UiO-66-NH_(2)and the calculated limiting potential is as low as-0.24 V.Moreover,the competitive hydrogen evolution reaction is unfavorable at the activation site of Ni_(1)/UiO-66-NH_(2)owing to the higher limiting potential of-0.56 V.Furthermore,the change of Ni single atom valence state plays an important role in promoting CO_(2)reduction to CH_(4).This work provides a theoretical foundation for further experimental studies and practical applications of metal-organic framework(UiO-66)-based SAC electrocatalysts with high activity and selectivity for the CO_(2)reduction reaction.

关键词： single atom catalyst density functional theory CO_(2)reduction metal-organic framework electrocatalysis

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Chinese Medicine Prolongs Overall Survival of Chinese Patients with Advanced Gastric Cancer: Treatment Pattern and Survival Analysis of a 20-Year Real-World Study

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Chinese Journal of Integrative Medicine 2024年第6期30卷 489-498页

作者： CAO Ni-da zhu Xiao-hong MA Fang-qi XU Yan DONG Jia-huan QIN Meng-meng LIU Tian-shu zhu chun-chao GUO Wei-jian DING Hong-hua GUO Yuan-biao LIU Li-kun SONG Jin-jie WU Ji-ping CHENG Yue-lei ZENG Lin ZHAO Ai-guang Oncology Department I Longhua Hospital Shanghai University of Traditional Chinese MedicineShanghai200032China Oncology Department Zhongshan HospitalFudan UniversityShanghai200032China Gastrointestinal Surgery Department Renji HospitalShanghai Jiaotong University School of MedicineShanghai200127China Oncology Department Fudan University Shanghai Cancer CenterShanghai200032China Oncology Department Shanghai General HospitalShanghai Jiaotong University School of MedicineShanghai200080China Traditional Chinese Medicine Department Ruijin HospitalShanghai Jiaotong University School of MedicineShanghai200025China Oncology Department Shanxi Traditional Chinese Medicine HospitalTaiyuan030012China Oncology Department Xiyuan HospitalChina Academy of Chinese Medical ScienceBeijing102445China Oncology Department Yunnan Province Hospital of Traditional Chinese MedicineKunming650021China Oncology Department Shuguang HospitalShanghai University of Traditional Chinese MedicineShanghai201203China Shanghai NewCore Biotechnology Co. Ltd.Shanghai200240China

Objective To describe the treatment patterns and survival status of advanced gastric cancer(AGC)in China in the past two decades,and objectively evaluate the impact of standardized Chinese medicine(CM)treatment on the survival of AGC patients.Methods This multicenter registry designed and propensity score analysis study described the diagnosis characteristics,treatment-pattern development and survival status of AGC from 10 hospitals in China between January 1,2000 and July 31,2021.Overall survival(OS)was evaluated between non-CM cohort(standard medical treatment)and CM cohort(integrated standard CM treatment≥3 months).Propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)were performed to adjust any difference in average outcomes for bias.Results A total of 2,001 patients histologically confirmed locally advanced and/or metastasis stomach and gastroesophageal junction adenocarcinoma were enrolled.Among them,1,607 received systemic chemotherapy,215(10.74%)accepted molecular targeted therapy,44(2.2%)received checkpoint inhibitor therapy,and 769(38.43%)received CM.Two-drug regimen was the main choice for first-line treatment,with fluoropyrimidine plus platinum as the most common regimen(530 cases,60.09%).While 45.71%(16 cases)of patients with HER2 amplification received trastuzumab in first-line.The application of apatinib increased(33.33%)in third-line.The application of checkpoint inhibitors has increased since 2020.COX analysis showed that Lauren mixed type(P=0.017),cycles of first-line treatment>6(P=0.000),CM(P=0.000),palliative gastrectomy(P=0.000),trastuzumab(P=0.011),and apatinib(P=0.008)were independent prognostic factors for the OS of AGC.After PSM and IPTW,the median OS of CM cohort and non-CM cohort was 18.17 and 12.45 months,respectively(P<0.001).Conclusions In real-world practice for AGC in China,therapy choices consisted with guidelines.Two-drug regimen was the main first-line choice.Standardized CM treatment was an independent prognostic factor and could prolong the OS of C

关键词： advancedgastriccancer real-world study treatment pattern survival analysis Chinese medicine

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Model test of negative Poisson’s ratio cable for supporting super-largespan tunnel using excavation compensation method

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1355-1369页

作者： Manchao He Aipeng Guo Zhifeng Du Songyuan Liu chun zhu Shiding Cao Zhigang Tao State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China Department of Civil and Mineral Engineering University of TorontoTorontoM5S 1A4Canada School of Earth Sciences and Engineering Hohai UniversityNanjing210098China Shenzhen General Integrated Transportation and Municipal Engineering Design and Research Institute Co.Ltd. Shenzhen518003China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

In recent years,there is a scenario in urban tunnel constructions to build super-large-span tunnels for traffic diversion and route optimization purposes.However,the increased size makes tunnel support more difficult.Unfortunately,there are few studies on the failure and support mechanism of the surrounding rocks in the excavation of supported tunnel,while most model tests of super-large-span tunnels focus on the failure characteristics of surrounding rocks in tunnel excavation without supports.Based on excavation compensation method(ECM),model tests of a super-large-span tunnel excavation by different anchor cable support methods in the initial support stage were carried out.The results indicate that during excavation of super-large-span tunnel,the stress and displacement of the shallow surrounding rocks decrease,following a step-shape pattern,and the tunnel failure is mainly concentrated on the vault and spandrel areas.Compared with conventional anchor cable supports,the NPR(negative Poisson’s ratio)anchor cable support is more suitable for the initial support stage of the super-large-span tunnels.The tunnel support theory,model test materials,methods,and the results obtained in this study could provide references for study of similar super-large-span tunnels。

关键词： Super-large-span tunnel Excavation compensation method(ECM) NPR(Negative Poisson’s ratio)anchor cable Model test

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Carbon cathode with heteroatom doping and ultrahigh surface area enabling enhanced capacitive behavior for potassium-ion hybrid capacitors

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Rare Metals 2024年第5期43卷 2136-2149页

作者： Yan Xiong Ya-Fei Zhang chun-Liu zhu Lei Yang Huan-Yu Liang Jing Shi Jing-Wei Chen Wei-Qian Tian Shuai Liu Zhi Li Jing-Yi Wu Huan-Lei Wang School of Materials Science and Engineering Ocean University of China Department of Chemical and Materials Engineering University of Alberta

Potassium-ion hybrid capacitors （PIHCs） are widely regarded as highly promising energy storage devices,due to their exceptional energy density,impressive power density,and abundant potassium resources.Unfortunately,restricted by the inherent capacitive storage mechanism,the carbon cathodes possess a much lower specific capacity than battery-type anodes.Therefore designing high-performance carbon cathodes is extremely urgent for the development of PIHCs.Herein,N,O codoped porous carbon （NOPC） was fabricated through the NaCl hard template method and combined KOH/melamine chemical activation technique,displaying the characteristics of abundant N/O content （4.7 at%/16.9 at%）,ultrahigh specific surface area (3092 m2·g-1) and hierarchical pore network.The designed NOPC cathode delivers a high specific capacity (164.4 mAh·g-1at 0.05 A·g-1) and superior cyclability (95.1%retention ratio at 2 A·g-1over2500 cycles).Notably,the adjustable ratio of micropores to mesopores facilitates the achievement of the optimal balance between capacity and rate capability.Moreover,the pseudocapacitance can be further augmented through the incorporation of N/O functional groups.As expected,the graphite//NOPC based PIHC possesses a high energy density of 113 Wh·kg-1at 747 W·kg-1and excellen capacity retention of 84.4%after 4000 cycles at 1.0 A·g-1This work introduces a novel strategy for designing carbon cathodes that enhances the electrochemical performance of PIHCs.

关键词： Template method N/O co-doping High specific surface area Carbon cathode Potassium-ion capacitors

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Shear sliding of rough-walled fracture surfaces under unloading normal stress

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2658-2675页

作者： Qian Yin chun zhu Jiangyu Wu Hai Pu Qi Wang Yuanchao Zhang Hongwen Jing Tianci Deng State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing100083China College of Civil Engineering Fuzhou UniversityFuzhou350108China

Through high-precision engraving,self-affine sandstone joint surfaces with various joint roughness coefficients(JRC=3.21e12.16)were replicated and the shear sliding tests under unloading normal stress were conducted regarding various initial normal stresses(1e7 MPa)and numbers of shearing cycles(1 e5).The peak shear stress of fractures decreased with shear cycles due to progressively smooth surface morphologies,while increased with both JRC and initial normal stress and could be verified using the nonlinear Barton-Bandis failure criterion.The joint friction angle of fractures exponentially increased by 62.22%e64.87%with JRC while decreased by 22.1%e24.85%with shearing cycles.After unloading normal stress,the sliding initiation time of fractures increased with both JRC and initial normal stress due to more tortuous fracture morphologies and enhanced shearing resistance capacity.The surface resistance index(SRI)of fractures decreased by 4.35%e32.02%with increasing shearing cycles due to a more significant reduction of sliding initiation shear stress than that for sliding initiation normal stress,but increased by a factor of 0.41e1.64 with JRC.After sliding initiation,the shear displacement of fractures showed an increase in power function.By defining a sliding rate threshold of 5105 m/s,transition from“quasi-static”to“dynamic”sliding of fractures was identified,and the increase of sliding acceleration steepened with JRC while slowed down with shearing cycles.The normal displacement experienced a slight increase before shear sliding due to deformation recovery as the unloading stress was unloaded,and then enhanced shear dilation after sliding initiation due to climbing effects of surface asperities.Dilation was positively related to the shear sliding velocity of fractures.Wear characteristics of the fracture surfaces after shearing failure were evaluated using binary calculation,indicating an increasing shear area ratio by 45.24%e91.02%with normal stress.

关键词： Unloading normal stress Rough fracture surface Shear sliding Normal displacement Shear wear characteristics

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通智测试——基于动态具身物理社会交互环境的通用人工智能测试

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Engineering 2024年第3期34卷 12-22页

作者： Yujia Peng Jiaheng Han Zhenliang Zhang Lifeng Fan Tengyu Liu Siyuan Qi Xue Feng Yuxi Ma Yizhou Wang Song-chun zhu National Key Laboratory of General Artificial Intelligence Beijing Institute for General Artificial IntelligenceBeijing 100086China Institute for Artificial Intelligence Peking UniversityBeijing 100871China Beijing Key Laboratory of Behavior and Mental Health School of Psychological and Cognitive SciencesPeking UniversityBeijing 100871China School of Intelligence Science and Technology Peking UniversityBeijing 100871China School of Computer Science Peking UniversityBeijing 100871China

The release of the generative pre-trained transformer(GPT)series has brought artificial general intelligence(AGI)to the forefront of the artificial intelligence(AI)field once again.However,the questions of how to define and evaluate AGI remain unclear.This perspective article proposes that the evaluation of AGI should be rooted in dynamic embodied physical and social interactions(DEPSI).More specifically,we propose five critical characteristics to be considered as AGI benchmarks and suggest the Tong test as an AGI evaluation system.The Tong test describes a value-and ability-oriented testing system that delineates five levels of AGI milestones through a virtual environment with DEPSI,allowing for infinite task generation.We contrast the Tong test with classical AI testing systems in terms of various aspects and propose a systematic evaluation system to promote standardized,quantitative,and objective benchmarks and evaluation of AGI.

关键词： Artificial general intelligence Artificial intelligence benchmark Artificial intelligence evaluation Embodied artificial intelligence Value alignment Turing test Causality

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