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Experimental study on the effect of unloading rate on gneiss rockburst

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2064-2076页

作者： Dongqiao liu Jie Sun ran Li Manchao He Binghao Cao Chongyuan Zhang Wen Meng State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China

Rockburst are often encountered in tunnel construction due to the complex geological *** study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in *** results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection *** mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of *** makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack ***,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation *** enlightenments of reducing the unloading rate for the project are also described *** rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

关键词： Rockburst Unloading rate Crack propagation Influence mechanisms

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Lead-free(Ba,Sr)TiO_(3)-based ceramics with superior tunable properties by the semi-solution method

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Journal of Advanced Ceramics 2024年第6期13卷 746-756页

作者： yi Zhao Wenfeng liu Dongsheng ran yihang Jin Zhiyuan Li Chengzhi Zhong Fanyi Kong Shengtao Li State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’an 710049China Jiaxing Electric Power Company State Grid Zhejiang Electric Power Co. Ltd.Jiaxing 314000China

High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable *** the present study,a new system,(Ba_(0.675)Sr_(0.325))_(1−x)La_(x)Ti_(1−x)MnxO_(3)(x=0.25%,0.5%,0.75%,and 1.0%),was *** acceptor dopant Mn was added to lower dielectric loss,while the donor dopant La was introduced to enhance dielectric *** samples were prepared using the conventional solid-state(CS)reaction method and the semi-solution(SS)*** experimental results showed that the morphology of the ceramics was optimized by further improving the processing *** microstructures,homogeneous grains,and uniform dopant distributions could be achieved successfully by the semi-solution ***,a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned *** optimum tunable properties occurred in the samples prepared by the semi-solution method at x=0.75%,with a high dielectric tunability of 85.0%,a low dielectric loss of 0.0011,and an excellent figure of merit(FOM)of *** tunable properties of(Ba,Sr)TiO_(3)(BST)ceramics were even superior to those of lead-based materials,with an FOM of approximately *** the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices.

关键词： microstructure tunable properties (Ba,Sr)TiO_(3)(BST)ceramics semi-solution(SS)method

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A Bitcoin Address Multi-Classification Mechanism Based on Bipartite Graph-Based Maximization Consensus

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 783-800页

作者： Lejun Zhang Junjie Zhang Kentaroh Toyoda yuan liu Jing Qiu Zhihong Tian ran Guo College of Information Engineering Yangzhou UniversityYangzhou225127China Cyberspace Institute Advanced Technology Guangzhou UniversityGuangzhou510006China Research and Development Center for E-Learning Ministry of EducationBeijing100039China Institute of High Performance Computing(IHPC) Agency for ScienceTechnology and Research(A∗STAR)Singapore138632Singapore School of Physics and Materials Science Guangzhou UniversityGuangzhou510006China

Bitcoin is widely used as the most classic electronic currency for various electronic services such as exchanges,gambling,marketplaces,and also scams such as high-yield investment *** the services operated by a Bitcoin address can help determine the risk level of that address and build an alert model *** engineering can also be used to flesh out labeled addresses and to analyze the current state of Bitcoin in a small *** this paper,we address the problem of identifying multiple classes of Bitcoin services,and for the poor classification of individual addresses that do not have significant features,we propose a Bitcoin address identification scheme based on joint multi-model prediction using the mapping relationship between addresses and *** innovation of the method is to(1)Extract as many valuable features as possible when an address is given to facilitate the multi-class service identification task.(2)Unlike the general supervised model approach,this paper proposes a joint prediction scheme for multiple learners based on address-entity mapping ***,after obtaining the overall features,the address classification and entity clustering tasks are performed separately,and the results are subjected to graph-basedmaximization *** final result ismade to baseline the individual address classification results while satisfying the constraint of having similarly behaving entities as far as *** testing and evaluating over 26,000 Bitcoin addresses,our feature extraction method captures more useful *** addition,the combined multi-learner model obtained results that exceeded the baseline classifier reaching an accuracy of 77.4%.

关键词： Bitcoin multi-service classification graph maximization consensus data security

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Unmanned Ship Identification Based on Improved yOLOv8s Algorithm

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Computers, Materials & Continua 2024年第3期78卷 3071-3088页

作者： Chun-Ming Wu Jin Lei Wu-Kai liu Mei-Ling Ren Ling-Li ran Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology School of Electrical EngineeringNortheast Electric Power UniversityJilin132012China School of Biomedical Engineering Taiyuan University of TechnologyTaiyuan030600China

Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved yOLOv8 algorithm(R_yOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model *** algorithm is validated in detail on two vessel *** comprehensive experimental results demonstrate that,in the infrared dataset,the yOLOv8s algorithm exhibits improvements in various performance ***,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_yOLO ***,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%.

关键词： Unmanned ships R_yOLO EMA CSPStage yOLOv8s

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Comprehensive evaluations of heat transfer performance with conjugate heat dissipation effect in high-speed rotating free-disk modeling of aero-engines

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Fundamental Research 2024年第3期4卷 611-623页

作者： Aqiang Lin Gaowen liu ran Chang yan Chen Qing Feng School of Power and Energy Northwestern Polytechnical UniversityXi'an 710129China Shaanxi Key Laboratory of Thermal Science in Aero-engine System Northwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwester

Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in *** study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various ***,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical *** particular,a novel combined solution method is proposed to simplify the complex heat transfer *** results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature *** heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds *** reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine ***,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.

关键词： Aero-engine Rotating turbine disk Dimensional analysis Compressibility Heat dissipation Dorfman empirical solution

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Systematical High-Pressure Study of Praseodymium Nitrides in N-Rich Region

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Chinese Physics Letters 2024年第6期41卷 67-87页

作者：刘冉刘爽张盈王鹏姚震 State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

We investigate high-pressure phase diagrams of Pr–N compounds by proposing five stable structures(PnmaPr N,Ⅰ4/mmm-PrN_(2),C2/m-PrN_(3),P■-PrN_(4),and R3-PrN_(8))and two metastable structures(P■-PrN_(6)and P■-PrN_(10)).The P■-PrN_(6)with the N14-ring layer and R3-PrN_(8)with the N18-ring layer can be quenched to ambient *** the P■-PrN_(10),the N_(22)-ring layer structure transfers into infinite chains with the pressure quenched to ambient ***,a novel polynitrogen h R8-N designed by the excision of Pr atoms from R3-PrN_(8)is obtained and can be quenched to ambient *** N-rich structures of P■-PrN_(6),R3-PrN_(8),c-PrN_(10)and the solid pure nitrogen structure exhibit outstanding properties of energy density and explosive performance.

关键词： ambient structure layer

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Prospective life cycle assessment of CO2 conversion by photocatalytic reaction

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Green Chemical Engineering 2024年第3期5卷 383-389页

作者： Jun-Qi Wang Xiang-Jun liu Jing-Jing Ma Shuai Zhang Hao-ran liu yong-Li Dong Qing-yuan yang School of Human Settlements and Civil Engineering Xi'an Jiaotong University School of Chemical Engineering and Technology Xi'an Jiaotong University

CO2conversion is gradually seen as a better way for society to effectively use carbon sources and avoid climate crisis associated with fossil CO2emissions. And the decision to deploy CO2technology scale should be relied on its environmental impact. In this work, life cycle assessment model evaluates the environmental performance of CO2conversion by photocatalytic reaction process with two different catalysts（NiAl-LDH and Co-ZIF-9）. Six impact categories considered in this analysis, including climate change, acidification potential, depletion of abiotic resources, eutrophication potential, ozone layer depletion potential, and photochemical oxidation potential. Results indicated that CO2conversion with Co-ZIF-9 photocatalyst has a better environmental impact than the NiAl-LDH photocatalyst route. Moreover, the Co-ZIF-9 catalyst scenario also has a lower total environmental burden than the conventional CO production route. Sensitivity analysis shows that recycle performance of the catalyst is highly sensitive to the production process in two scenarios. This study could provide a framework for robust decisions in CO2conversion by photocatalytic reaction, which is useful for policymakers to decide the feasibility of industrialization.

关键词： Life cycle assessment (LCA) CO 2 Photocatalytic reaction Sensitivity analysis Uncertainty analysis

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Groundwater Quality and Vulnerability Assessment in a Semiarid Karst Region of Northern China

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Journal of Earth Science 2024年第1期35卷 313-316页

作者： ran An Shu Wang Zongjun Gao Zhenyan Wang Wei Li Qijun Deng Lü Lin yuanqing liu Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Shandong University of Science and Technology Qingdao 266510China Center for Hydrogeology and Environmental Geology Survey China Geological SurveyBaoding 071051China

Groundwater plays a critical role in maintaining ecological balance and ensuring social operations,especially in arid and semiarid regions(Hu et al.,2023;Han et al.,2022;Ma et al.,2014).The over-exploitation of groundwater,coupled with the influx of pollutants from human activities into the soil,significantly degrades the environment in certain regions(Jia et al.,2019;Famiglietti,2014;Giordano,2009;Konikow and Kendy,2005;Bohlke,2002;Shah et al.,2000).

关键词： groundwater Groundwater Vul

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Biochar alleviates apple replant disease by reducing the growth of Fusarium oxysporum and regulating microbial communities

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Horticultural Plant Journal 2024年第3期10卷 657-671页

作者： yinghao liu Can Wang ran Chen Weitao Jiang yun Li Chengmiao yin yanfang Wang Zhiquan Mao College of Chemistry and Material Science Shandong Agricultural UniversityTaianShandong 271018China State Key Laboratory of Crop Biology/College of Horticultural Science and Engineering Shandong Agricultural UniversityTaianShandong 271018China

Apple replant disease(ARD)negatively affects plant growth and reduces yields in replanted *** this study,biochar was applied to apple replant soil with Fusarium *** aim was to investigate whether biochar could promote plant growth and alleviate apple replant disease by reducing the growth of harmful soil microorganisms,changing soil microbial community structure and improving the soil *** experiment included five treatments:apple replant soil(CK),methyl bromide fumigation apple replant soil(FM),replant soil with biochar addition(2%),replant soil with *** spore solution(8×10^(7)spores·mL^(-1)),and replant soil with biochar and *** spore solution *** biomass,the activity of antioxidant enzymes in the leaves and roots,and soil environmental variables were *** community composition and community structure were analyzed using 16SrDNA and ITS2 gene *** significantly reduced the abundance of *** and increased soil microbial diversity and *** also increased the soil enzyme activities(urease,invertase,neutral phosphatase,and catalase),the biomass(plant height,fresh weight,dry weight)and the activity of antioxidant enzymes(superoxide dismutase,peroxidase,and catalase).The root indexes of apple seedlings was also increased in replant soil by *** sum,biochar promoted the growth of plants,improved the replant soil environment,and alleviated apple replant disease.

关键词： Biochar Fusarium oxysporum Apple replant disease Soil environment

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Advances in brain tumor therapy: from molecular diagnostics to novel treatments

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Science China Life Sciences 2024年

作者： Junwen Zhang ran Mu Fusheng liu Brain Tumor Research Center Beijing Neurosurgical Institute Capital Medical University Department of Neurosurgery Beijing Tiantan Hospital Capital Medical University

With the rapid increase in incidence and mortality, brain tumors have become a major social, economic, and public health problem worldwide. According to the latest report from the International Agency for Research on Cancer (IARC),there are approximately 320,000 new cases and 250,000 deaths from brain and central nervous system (CNS) tumors each year. The incidence and mortality rates rank 19th and 12th among all cancers (Bray et al., 2024), respectively,and are particularly prevalent in East Asia, Western Europe, and South *** like San Marino, Denmark, and Norway have the highest age-standardized incidence rates, while Central Europe and tropical Latin America have the highest age-standardized mortality and disability-adjusted life-year (DALy) rates.

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