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Design and flow field analysis of impregnated diamond bit for seafloor drill in soft-hard interlaced strata

Journal of engineering and Applied science 2022年第1期69卷 1-15页

作者： Wang, Jialiang Chen, Chen Qian, Dilei Peng, Fenfei Yu, Mengfei Sun, Yang Peng, Deping National Local Joint Engineering Laboratory of Marine Mineral Resources Exploration Equipment and Safety Technology Hunan University of Science and Technology Xiangtan411201 China Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Central South University Ministry of Education Changsha China School of Mechanical Engineering Hunan University of Science and Technology Xiangtan411201 China Xiangtan Huajin Heavy Equipment Co. Ltd. Shaoshan411300 China

According to the seafloor drill working conditions and the complex formation characteristics of the seafloor, this paper aims to improve the adaptability of the diamond bit to the formation and the coring quality. The cutter tooth design scheme of the impregnated diamond bit is proposed, and Fluent analyzes the flow field of drilling fluid at the bottom hole. The results show that the cone cutting tooth bit with the primary and assistant nozzles can directly avoid 85.33% drilling fluid flushing core and reduce the disturbance of drilling fluid to the core samples. The water passage structure of the bit is reasonable, and the upward return velocity of the drilling fluid can be stabilized between 0.7 and 1.8 m/s, which meets the requirements of the upward return of cuttings in seabed strata, and has a good hole wall protection performance. Based on the bottom-jet diamond bit, the assistant nozzles are added. The drilling fluid of the assistant nozzles can better cover the bit crown, conductive to cooling the bit crown. The drilling fluid of the main nozzles can timely up-return along the outer annulus hole wall, conducive to the up-return of the cuttings with drilling fluid. This study can extend existing designs of a seafloor coring bits and bottom hole flow field analysis methods. © 2022, The Author(s).

关键词： Drilling fluids

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Climate warming advances plant reproductive phenology in China’s northern grasslands

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Journal of Plant Ecology 2024年第6期17卷 225-240页

作者： Lu Bai Lei Tian Zhiguo Ren Xiaohui Song Kailiang Yu Lin Meng Zhanfeng Hou Haiyan Ren Key Laboratory of Grassland Resources of the Ministry of Education Key Laboratory of Forage CultivationProcessing and High Effcient Utilization of the Ministry of Agriculture and Rural AffairsInner Mongolia Key Laboratory of Grassland Management and UtilizationCollege of Grassland ScienceInner Mongolia Agricultural UniversityHohhot 010011China National Center of Pratacultural Technology Innovation(under preparation Mengcao Ecological Environment(Group)Co. Ltd.Hohhot 010070China New Path Education Co.Ltd Hohhot 010010China High Meadows Environmental Institute Princeton UniversityPrincetonNJ 08544USA Department of Earth and Environmental Sciences Vanderbilt UniversityNashvilleTN 37240USA College of Mechanical and Electrical Engineering Inner Mongolia Agricultural UniversityHohhot 010018China

Despite much recent progress,our understanding of plant phenology response to climate change remains *** particular,how and to what extent climate warming affects the vegetative and reproductive phenology of different plant functional groups in northern grassland ecosystems remains largely ***,we compiled data of 1758 observations from 25 individual studies and carried out a meta-analysis of plant phenology in relation to temperature changes across a range of plant species and functional groups in northern *** show that climate warming tended to extend the duration of reproductive phenology while having no effect on the duration of vegetative *** also identified specific temperature sensitivities for different phenological stages:1.73 days°C^(−1) for budding,−3.38 days°C^(−1) for leaf spreading and 0.56 days°C^(−1) for yellow withered stage,***,warming resulted in earlier leaf spreading in shrubs and semi-shrubs,but caused a delay in the budding time of *** terms of reproductive phenology,temperature sensitivity was−1.73 days°C^(−1) for flowering time,−2.53 days°C^(−1) for fruit ripening and−0.11 days°C^(−1) for fruit shedding,*** advanced the flowering and fruit repining time of all functional groups except for *** results indicate that elevated temperatures advanced reproductive phenology and extended its duration in northern grasslands,while showing no impact on vegetative *** findings demonstrate the differential responses of different functional groups to warming,highlighting the diverse growth strategies and adaptation of grassland plants in a warming world.

关键词： Climate change grassland reproductive phenology vegetative phenology plant functional groups

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Bioresource Upgrade for Sustainable Energy,environment,and Biomedicine

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Nano-Micro Letters 2023年第3期15卷 48-97页

作者： Fanghua Li Yiwei Li KSNovoselov Feng Liang Jiashen Meng Shih‑Hsin Ho Tong Zhao Hui Zhou Awais Ahmad Yinlong Zhu Liangxing Hu Dongxiao Ji Litao Jia Rui Liu Seeram Ramakrishna Xingcai Zhang Center for Nanofibers and Nanotechnology National University of SingaporeSingapore 119260Singapore State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090People’s Republic of China School of Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA John A Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics–Department of Biomedical Engineering College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanHubei 430074People’s Republic of China Centre for Advanced 2D Materials National University of SingaporeSingapore 117546Singapore School of Physics and Astronomy The University of ManchesterManchester M139PLUK Department of Anesthesia Critical Care and Pain MedicineMassachusetts General Hospital and Harvard Medical SchoolBostonMA 02114USA Department of Energy and Power Engineering Tsinghua UniversityBeijing 100084People’s Republic of China Departamento de Quimica Organica Universidad de CordobaEdificio Marie Curie(C‑3)Ctra Nnal IV‑AKm 39614014 CordobaSpain Department of Chemical Engineering Monash UniversityClaytonVIC 3800Australia School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

We conceptualize bioresource upgrade for sustainable energy,environment,and biomedicine with a focus on circular economy,sustainability,and carbon neutrality using high availability and low utilization biomass(HALUB).We acme energy-efficient technologies for sustainable energy and material recovery and *** technologies of thermochemical conversion(TC),biochemical conversion(BC),electrochemical conversion(EC),and photochemical conversion(PTC)are summarized for *** biomass could contribute to a biofuel HHV of 35.72 MJ Kg^(-1)and total benefit of 749$/ton biomass via *** surface area of biochar reached 3000 m^(2)g^(-1)via pyrolytic carbonization of waste bean *** biomass can be effectively converted into bio-stimulants and biofertilizers via BC with a high conversion efficiency of more than 90%.Besides,lignocellulosic biomass can contribute to a current density of 672 mA m^(-2)via *** can be 100%selectively synthesized via electrocatalysis through EC and *** learning,techno-economic analysis,and life cycle analysis are essential to various upgrading approaches of *** biomaterials,sustainable living materials and technologies for biomedical and multifunctional applications like nano-catalysis,microfluidic and micro/nanomotors beyond are also *** techniques and systems for the complete conversion and utilization of HALUB for new energy and materials are further discussed.

关键词： High availability low utilization biomass(HALUB) Circular economy Machine learning Energy-efficient conversion Nano-catalysis

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RESEARCH ON THE MATURITY ASSESSMENT METHOD OF INTELLIGENT PHM FOR GROUNDWATER CIRCULATION WELL 13

RESEARCH ON THE MATURITY ASSESSMENT METHOD OF INTELLIGENT PH...

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13th International Conference on Quality, reliability, Risk, Maintenance, and Safety engineering, QR2MSE 2023

作者： Yang, Bingrui Zhang, Lianjie Yang, Ruifeng Miao, Zhu Wang, Peng Pu, Shengyan Xu, Huyang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu China College of Ecology and Environment Chengdu University of Technology Chengdu China College of Management Science Chengdu University of Technology Chengdu China BCEG Environmental Remediation Co. Ltd. National Engineering Laboratory for Site Remediation Technologies Beijing China Beijing GeoEnviron Engineering and Technology Inc. Beijing China

ISBN: (纸本)9781839539848

GCW system is one of the hot research objects of in-situ remediation of contaminated groundwater. However, the system will be difficult to maintain if there is a failure during underground operation. The uncertainty of the source of the failure will make it more difficult to perform maintenance on the system, which will delay the remediation process. Therefore, a method that can diagnose or predict system failures in a timely manner is needed. Based on RPL, this study designs an intelligent PHM system to predict potential failures of GCW systems based on the relationship between performance degradation and failure time of GCW systems. And the maturity of the intelligent PHM system is evaluated into 5 levels, and 15 maturity evaluation factors in 4 dimensions are proposed. The maturity model and its application process are obtained. This modeling method provides ideas for decision-makers and managers to carry out early maintenance, and estimate its development level in related fields. © The Institution of engineering & technology 2023.

关键词： Groundwater

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Tianwen-1 MINPA observations in the solar wind

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Earth and Planetary Physics 2022年第1期6卷 1-9页

作者： AiBing Zhang LingGao Kong WenYa Li Lei Li BinBin Tang ZhaoJin Rong Yong Wei JiJie Ma YiTeng Zhang LiangHai Xie YuXian Wang JianSen He Bin Liu WenJing Wang Bin Su JiaWei Li Xu Tan Fang Wang TaiFeng Jin FuHao Qiao Peter Wurz Yan Zhu YunFei Bai YiRen Li XinBo Zhu YueQiang Sun YongLiao Zou Chi Wang National Space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on Space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China Lunar Exploration and Space Engineering Center Beijing 100190China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Physics Institute University of BernBern 3012Switzerland University of Science and Technology of China Hefei 230026China Shanghai Academy of Spaceflight Technology Shanghai 201109China

The Mars Ion and Neutral Particle Analyzer(MINPA)is one of the three scientific instruments onboard the Tianwen-1 orbiter to investigate the Martian space *** Tianwen-1’s transfer orbit to Mars,the MINPA was switched on to measure the solar wind ***,we present the first results of the MINPA observations in the solar *** cruise,nearly half of the MINPA ion field-of-view(FOV)was blocked by the lander capsule;thus only the solar-wind ions with azimuthal speeds pointing towards the unblocked FOV sectors could be *** perform a detailed comparison of the MINPA’s solar wind observations with data from Earth-based missions when MINPA reached its count-rate peak,finding a general consistency of the ion moments between *** blocking effect due to the lander is evaluated quantitatively under varying solar-wind velocity *** the blocking effect,the MINPA’s solar wind measurements during the transfer orbit suggest a good performance.

关键词： MINPA Tianwen-1 solar wind capsule blocking effect

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High-density/efficient surface active sites on modified separators to boost Li-S batteries via atomic Co^(3+)-Se termination

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Nano Research 2022年第8期15卷 7199-7208页

作者： Shujie Liu Xiaofei Liu Manfang Chen Dong Wang Xin Ge Wei Zhang Xiyang Wang Chunhui Wang Tingting Qin Haozhe Qin Liang Qiao Dan Zhang Xing Ou Weitao Zheng Key Laboratory of Automobile Materials of MOE School of Materials Science and Engineeringand Electron Microscopy Centerand International Center of Future ScienceJilin UniversityChangchun 130013China Key Laboratory of Materials Design and Quantum Simulation College of ScienceChangchun UniversityChangchun 130022China National Base for International Science&Technology Cooperation School of ChemistryXiangtan UniversityXiangtan 411105China State Key Laboratory of Chem/Bio-Sensing and Chemometrics Advanced Catalytic Engineering Research Center of the Ministry of EducationCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooN2L 3G1Canada School of Metallurgy and Environment Central South UniversityChangsha 410083China

Various and critical electrocatalytic processes are involved during the redox reactions in the Li-S batteries,which extremely depend on the surface structure and chemical ***,single-atom concept unlocks a route to maximize the use of surface-active atoms,however,further increasing the density of active site is still strictly limited by the inherent structure that single-atoms are only highly-dispersed on ***,we provide a viewpoint that an elaborate facet design with singlecrystalline structure engineering can harvest high-density surface active sites,which can significantly boost the electrocatalyst performance for excellent Li-S ***,the single-crystal CoSe_(2)(scCS)exhibits three-types of terminated(011)facet,efficiently obtaining the surface with a high-rich Co^(3+)–Se bond termination,in contrast with lots of surface grain boundaries and dangling bonds in polycrystalline CoSe_(2).Surprisingly,the surface active sites concentration can reach more than 69%.As anticipated,it can provide high-density and high-efficient active sites,enormously suppressing the shuttle effect and improving the reaction kinetics via accelerating the conversion and deposition of polysulfides and *** surface lattice strategy with element terminated mode is a promising approach for designing electrocatalyst effect-based energy system,not merely for Li-S batteries.

关键词： high-density surface active sites Co^(3+)-Se covalent bond atomic element terminated Li-S batteries single-crystalline strategy

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Using Load Transient Waveform to Analyze Fault Propagation Mechanism in DC-DC Switching Power Supply

Using Load Transient Waveform to Analyze Fault Propagation M...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Junliang Wan Pengfei Yu Qiang-Ming Cai Xin Cao Longjian Zhou Haoran Li Yuyu Zhu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Laboratory of Science and Technology on Reliability Physics and Application of Electronic Component Guangzhou China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

The degradation of certain components within DC-DC power supplies can lead to abnormal performance, resulting in the occurrence of faults. The degradation of components can cause changes in output voltage and current, and the different degradation characteristics of components have different impacts on the characteristics of output parameters. Therefore, it is necessary to master this impact relationship, that is, the fault propagation mechanism can be used to effectively diagnose faults and manage health. Studying the fault propagated mechanism is an important prerequisite for fault diagnosis. Output terminals of DC-DC power supply are usually connected in parallel with electrolytic capacitors. The function of electrolytic capacitors is to filter, filtering out most of the AC part of the output voltage, and reducing the ripple of the output voltage. Electrolytic capacitors are the most vulnerable components to failure in switching power supplies, with approximate 60% of failed components being electrolytic capacitors. Therefore, the fault propagation mechanism of electrolytic capacitors is a key research topic. Most research focuses on the fault propagation mechanism based on steady-state output signals. This article studies the fault propagation mechanism based on transient output signals. Through experimental testing, the impact of parameter degradation of electrolytic capacitors on the transient waveform of output voltage and the mapping relationship between capacitor degraded parameters and transient waveform are studied. The method is to analyze the voltage waveform when the current step changes using equivalent degradated experiments of capacitors. Its advantage lies in the fact that transient waveforms are more sensitive than steady-state waveforms and require lower sampling rates, making it easier to analyze the degradated characteristics of electrolytic capacitors. For power supplies with simple structures, data is collected through simulation. For commerc

关键词： Degradation Resistance Power supplies Capacitors Voltage Switches Capacitance

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Pre-Trained Large Language Model Based Remaining Useful Life Transfer Prediction of Bearing

arXiv

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arXiv 2025年

作者： Tao, Laifa Zhao, Zhengduo Wang, Xuesong Li, Bin Zhan, Wenchao Su, Xuanyuan Li, Shangyu Huang, Qixuan Liu, Haifei Lu, Chen Lian, Zhixuan Hangzhou International Innovation Institute Beihang University China Institute of Reliability Engineering Beihang University China National Key Laboratory of Science and Technology on Reliability and Environmental Engineering China School of Reliability and Systems Engineering Beihang University China China Electronics Information Industry Group Co. Ltd. Sixth Research Institute Beijing China

Accurately predicting the remaining useful life (RUL) of rotating machinery, such as bearings, is crucial for equipment reliability and minimizing unexpected failures in industrial systems. Despite recent advancements, data-driven deep learning methods face challenges in practical industrial settings due to inconsistent data distributions between training and testing phases, and limited generalization capabilities for long-term RUL predictions. To address these issues, we propose LM4RUL, a framework for RUL prediction based on pre-trained Large language Model (LLM). LM4RUL leverages the generalization and reasoning capabilities of LLM to transfer predictive knowledge from pre-training, effectively overcoming data inconsistencies and enhancing prediction accuracy. This represents a meaningful advancement in the artificial intelligence field, being among the first efforts to successfully apply LLM to RUL prediction tasks without the need for additional manual instruction, thereby extending the boundaries of AI applications beyond natural language processing and into complex industrial scenarios. The framework includes the local scale perception representation component, which captures fine-grained bearing degradation trends by tokenizing vibration data, and hybrid embedding learning, which selectively freezes and fine-tunes parameters to model complex nonlinear degradation. A two-stage fine-tuning approach further integrates pre-trained knowledge, enhancing adaptability without complex architectures. Experiments on authoritative datasets demonstrate that LM4RUL significantly improves long-term RUL prediction and adaptability, achieving high precision and robustness. This work bridges a critical gap in RUL prediction with advanced AI techniques and highlights its practical impact on equipment reliability and operational safety, showcasing its value for predictive maintenance in industrial AI applications. Copyright © 2025, The Authors. All rights reserved.

关键词： Deep learning

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3D reconstruction of coal pore network and its application in CO_(2)-ECBM process simulation at laboratory scale

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Frontiers of Earth science 2022年第2期16卷 523-539页

作者： Huihuang FANG Hongjie XU Shuxun SANG Shiqi Liu Shuailiang SONG Huihu LIU State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China School of Earth and Environment Anhui University of Science and TechnologyHuainan 232001China Institute of Energy Hefei Comprehensive National Science CenterHefei 230000China Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhou 221008China Low Carbon Energy Institute China University of Mining and TechnologyXuzhou 221008China Shandong Provincial Lunan Geo-engineering Exploration Institute Jining 272100China

Three-dimensional(3D)reconstruction of the equivalent pore network model(PNM)using X-ray computed tomography(CT)data are of significance for studying the CO_(2)-enhanced coalbed methane recovery(CO_(2)-ECBM).The docking among X-ray CT technology,MATLAB,with COMSOL software not only can realize the 3D reconstruction of PNM,but also the CO_(2)-ECBM process *** results show that the Median filtering algorithm enabled the de-noising of the original 2D CT slices,the image segmentation of all slices was realized based on the selected threshold,and the PNM can be constructed based on the Maximum Sphere *** mathematical model of CO_(2)-ECBM process fully coupled the expanded Langmuir *** the same time for CO_(2)injection,CH_(4)pressure tends to decrease with the increase of CO_(2)pressure,but its difference is not *** CH_(4)pressure in the slice center changed a lot,while at the edge it changed a little under different CO_(2)*** injected CO_(2)was transported to matrix along the macro and micro-fractures with continuous *** injected CO_(2)first replaced the adsorbed CH_(4)by covering the inner surface of macro-pores and meso-pores to form the single molecular layer adsorption of CO_(2).Then they migrated to micro-pores by Fick’s diffusion,sliding flow,and surface ***,the CO_(2)replaced CH_(4)adsorbed by volumetric filling in micro-pores,and formed the multi-molecular layer adsorption of CO_(2).The gas pressure and migration path between CO_(2)and CH_(4)are *** study can provide a theoretical basis for studying digital rock physics technology and enrich the development of CO_(2)-ECBM technology.

关键词： CO_(2)-ECBM 3D reconstruction numerical simulation X-ray CT COMSOL Qinshui Basin

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In-situ observation of wave-induced pore water pressure in seabed silt in the yellow river estuary of China

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Journal of Marine environmental engineering 2021年第4期10卷 305-317页

作者： Du, Xing Sun, Yongfu Song, Yupeng Zhu, Chaoqi First Institute of Oceanography MNR Qingdao266061 China Pilot National Laboratory for Marine Science and Technology Qingdao266000 China National Deep Sea Center Qingdao266237 China College of Earth Science and Engineering Shandong University of Science and Technology Qingdao266590 China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of China Qingdao266100 China Hainan Key Laboratory of Marine Geological Resources and Environment Haikou570206 China

Variation of pore water pressure in soil grains, caused by the force of waves repeatedly acting on the seabed, is the main reason for soil liq-uefaction. In the study of wave-induced pore pressure response, field monitoring is closer to the real situation than other research methods. In this study, pore pressure in the easily liq-uefied zone of the Yellow River Estuary was measured in a long-term, high-precision way using self-designed pore pressure observation equipment. Both total and excess pore pressure were analyzed by comparison with the hydrodynamic conditions. Results showed that the total pore pressure was influenced by waves and tides, whereas excess pore pressure was influenced only by waves. Transient liquefaction occurred at a seabed depth of 0.5 meters (m), but no residual liquefaction occurred during the observation period. The maximum depth at which waves influenced pore pressure was between 0.5 and 1.5 m. The factors influencing pore pressure and the reason there was no residual liquefaction are discussed. The effects of pore water pressure response are mainly determined by the rela-tionship between hydrodynamic action and the soil’s liquefaction resistance. By comparing normalized in situ observation data and water flume test data, we found that the effect of waves on pore water pressure under actual marine conditions is much smaller than that in water flume tests with equal scale reduction. To better represent the wave-induced pore pressure response results, the relationships between pore pressure increments induced by waves and decrements due to seepage are summarized in a graph and divided into three categories: no response, oscillatory without accumulation, and affective accumulation. © 2021 Old City Publishing, Inc.

关键词： Pore pressure

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