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Hole cleaning evaluation and installation spacing optimization of cuttings bed remover in extended-reach drilling

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Petroleum Science 2024年第3期21卷 2005-2022页

作者： Shuo Peng Wen-Jun Huang De-Li Gao moe key laboratory of Petroleum Engineering China University of Petroleum-Beijing State key laboratory of Petroleum Resources and Engineering China University of Petroleum-Beijing

In extended-reach or long-horizontal drilling, cuttings usually deposit at the bottom of the annulus. Once cuttings accumulate to a certain thickness, complex problems such as excessive torque and drag, tubing buckling, and pipe stuck probably occur, which results in a lot of non-productive time and remedial operations. Cuttings bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring effects. This paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning effect. Firstly,a computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation, and a new type of cuttings bed remover was designed. Next, an evaluation method of hole cleaning effect of remover was established. After that, the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid, rotational speed of drillpipe, rate of penetration, wellbore size, rheological property of drilling fluid, and remover eccentricity on the performance of cuttings bed remover were investigated. The results demonstrate that the new type of remover with streamline blade performs better than conventional removers. The efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe, flow rate of drilling fluid, remover eccentricity, and 6 rpm Fann dial reading for drilling fluid. While higher rate of penetration and large wellbore size result in worse hole cleaning. These findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers.

关键词： Extended-reach drilling Drilling hydraulics Cuttings transport Hole cleaning Cuttings bed remover

Orbital-Ordering Driven Simultaneous Tunability of Magnetism and Electric Polarization in Strained Monolayer VCl_(3)

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Chinese Physics Letters 2024年第4期41卷 126-131页

作者：郭的坪王聪王侣锦陆赟豪吴骅张妍宁季威 Beijing key laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China key laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China Zhejiang Province key laboratory of Quantum Technology and Device State Key Laboratory of Silicon MaterialsDepartment of PhysicsZhejiang UniversityHangzhou 310027China laboratory for computational Physical Sciences(moe) State Key Laboratory of Surface Physicsand Department of PhysicsFudan UniversityShanghai 200433China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).

关键词： monolayer symmetry orbital

Suitable region of dynamic optimal interpolation for efficiently altimetry sea surface height mapping

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Geodesy and Geodynamics 2024年第2期15卷 142-149页

作者： Jiasheng Shi Taoyong Jin School of Geodesy and Geomatics Hubei Luojia LaboratoryWuhan UniversityWuhan 430079China moe key laboratory of Geospace Environment and Geodesy Wuhan UniversityWuhan 430079China

The dynamic optimal interpolation(DOI)method is a technique based on quasi-geostrophic dynamics for merging multi-satellite altimeter along-track observations to generate gridded absolute dynamic topography(ADT).Compared with the linear optimal interpolation(LOI)method,the DOI method can improve the accuracy of gridded ADT locally but with low computational efficiency.Consequently,considering both computational efficiency and accuracy,the DOI method is more suitable to be used only for regional applications.In this study,we propose to evaluate the suitable region for applying the DOI method based on the correlation between the absolute value of the Jacobian operator of the geostrophic stream function and the improvement achieved by the DOI method.After verifying the LOI and DOI methods,the suitable region was investigated in three typical areas:the Gulf Stream(25°N-50°N,55°W-80°W),the Japanese Kuroshio(25°N-45°N,135°E-155°E),and the South China Sea(5°N-25°N,100°E-125°E).We propose to use the DOI method only in regions outside the equatorial region and where the absolute value of the Jacobian operator of the geostrophic stream function is higher than1×10^(-11).

关键词： Dynamic optimal interpolation Linearoptimal interpolation Satellite altimetry Sea surface height Suitable region

Toward understanding the role of genomic repeat elements in neurodegenerative diseases

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Neural Regeneration Research 2025年第3期20卷 646-659页

作者： Zhengyu An Aidi Jiang Jingqi Chen Institute of Science and Technology for Brain-Inspired Intelligence Fudan UniversityShanghaiChina moe Frontiers Center for Brain Science Fudan UniversityShanghaiChina moe key laboratory of computational Neuroscience and Brain-Inspired Intelligence Fudan UniversityShanghaiChina Zhangjiang Fudan International Innovation Center ShanghaiChina

Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.

关键词： Alzheimer's disease ataxia deep learning long-read sequencing neurodegeneration neurodegenerative diseases Parkinson's disease repeat element structural variant

Deep Broad Learning for Emotion Classification in Textual Conversations

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Tsinghua Science and Technology 2024年第2期29卷 481-491页

作者： Sancheng Peng Rong Zeng Hongzhan Liu Lihong Cao Guojun Wang Jianguo Xie Center for linguistics and Applied linguistics and Laboratory of Language Engineering and ComputingGuangdong University of Foreign StudiesGuangzhou 510006China Guangdong Provincial key laboratory of Nanophotonic Functional Materials and Devices South China Normal UniversityGuangzhou 510006China School of Computer Science and Cyber Engineering Guangzhou UniversityGuangzhou 510006China Modern Education Technology Center Guangdong University of Foreign StudiesGuangzhou 510006China

Emotion classification in textual conversations focuses on classifying the emotion of each utterance from textual conversations.It is becoming one of the most important tasks for natural language processing in recent years.However,it is a challenging task for machines to conduct emotion classification in textual conversations because emotions rely heavily on textual context.To address the challenge,we propose a method to classify emotion in textual conversations,by integrating the advantages of deep learning and broad learning,namely DBL.It aims to provide a more effective solution to capture local contextual information(i.e.,utterance-level)in an utterance,as well as global contextual information(i.e.,speaker-level)in a conversation,based on Convolutional Neural Network(CNN),Bidirectional Long Short-Term Memory(Bi-LSTM),and broad learning.Extensive experiments have been conducted on three public textual conversation datasets,which show that the context in both utterance-level and speaker-level is consistently beneficial to the performance of emotion classification.In addition,the results show that our proposed method outperforms the baseline methods on most of the testing datasets in weighted-average F1.

关键词： emotion classification textual conversation Convolutional Neural Network(CNN) Bidirectional Long Short-Term Memory(Bi-LSTM) broad learning

机器学习方法及应用:光电半导体材料计算设计

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Science China Materials 2024年第4期67卷 1042-1081页

作者：杨晓雨周琨贺欣张立军 State key laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOEKey Laboratory of Material Simulation Methods&Software of MOEand School of Materials Science and EngineeringJilin UniversityChangchun 130012China

高通量计算与材料数据库推动了数据驱动的机器学习方法的发展.机器学习已经成为材料计算研究的重要方法,在分析材料数据、加速材料计算、预测材料性质、推进新材料发现、筛选和设计等方面展现出极大的潜力.众多与材料计算相交叉的机器... 详细信息

高通量计算与材料数据库推动了数据驱动的机器学习方法的发展.机器学习已经成为材料计算研究的重要方法,在分析材料数据、加速材料计算、预测材料性质、推进新材料发现、筛选和设计等方面展现出极大的潜力.众多与材料计算相交叉的机器学习方法、模型以及框架不断涌现.本文综述了近年来光电半导体材料计算设计领域内机器学习方法的最新进展与应用.介绍了机器学习的流程与类型,基于不同材料表示方法的浅层模型、集成模型和深度神经网络,以及相关材料数据库和相关工具.我们还讨论了这些模型在预测材料稳定性与光电性质、材料逆向设计、构建材料构效关系等方面的应用.最后,本文对目前机器学习方法存在的机遇与挑战,即数据数量与质量、材料的表示、材料逆向设计做了进一步总结与讨论.

关键词：材料数据库机器学习深度神经网络逆向设计数据驱动材料计算集成模型光电性质

Cooperative activation of sodium channels for downgrading the energy efficiency in neuronal information processing

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Chinese Physics B 2024年第5期33卷 758-763页

作者：严浩然颜家琦俞连春邵玉峰 School of Physical Science and Technology Lanzhou Center for Theoretical PhysicsLanzhou UniversityLanzhou 730000China key laboratory of Theoretical Physics of Gansu Province and Key Laboratory of Quantum Theory and Applications of MoELanzhou UniversityLanzhou 730000China Department of Neuroscience AnatomyHistologyand EmbryologyKey Laboratory of Preclinical Study for New Drugs of Gansu ProvinceSchool of Basic Medical SciencesLanzhou UniversityLanzhou 730000China

The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel activation.In this study,we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy consumption.Simulations of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that,while cooperative activation enhances neuronal information processing capacity,it greatly increases the neuron’s energy consumption.As a result,cooperative activation of sodium channel degrades the energy efficiency for neuronal information processing.This discovery improves our understanding of the design principles for neural systems,and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases.

关键词： energy efficiency ion channel noise action potential generation neuronal dynamics

Effect of bipolar-plates design on corrosion,mass and heat transfer in proton-exchange membrane fuel cells and water electrolyzers:A review

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1599-1616页

作者： Jiuhong Zhang Xiejing Luo Yingyu Ding Luqi Chang Chaofang Dong key laboratory for Corrosion and Protection(moe) Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing 100083China

Attaining a decarbonized and sustainable energy system,which is the core solution to global energy issues,is accessible through the development of hydrogen energy.Proton-exchange membrane water electrolyzers(PEMWEs)are promising devices for hydrogen production,given their high efficiency,rapid responsiveness,and compactness.Bipolar plates account for a relatively high percentage of the total cost and weight compared with other components of PEMWEs.Thus,optimization of their design may accelerate the promotion of PEMWEs.This paper reviews the advances in materials and flow-field design for bipolar plates.First,the working conditions of proton-exchange membrane fuel cells(PEMFCs)and PEMWEs are compared,including reaction direction,operating temperature,pressure,input/output,and potential.Then,the current research status of bipolar-plate substrates and surface coatings is summarized,and some typical channel-rib flow fields and porous flow fields are presented.Furthermore,the effects of materials on mass and heat transfer and the possibility of reducing corrosion by improving the flow field structure are explored.Finally,this review discusses the potential directions of the development of bipolar-plate design,including material fabrication,flow-field geometry optimization using threedimensional printing,and surface-coating composition optimization based on computational materials science.

关键词： bipolar-plates flow design mass and heat transfer corrosion water electrolyzers fuel cells

Effect of bubble morphology and behavior on power consumption in non-Newtonian fluids’aeration process

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Chinese Journal of Chemical Engineering 2024年第1期65卷 243-254页

作者： Xiemin Liu Jing Wan Jinnan Sun Lin Zhang Feng Zhang Zhibing Zhang Xinyao Li Zheng Zhou key laboratory of Mesoscopic Chemistry of Ministry of Education(moe) School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116045China

Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.

关键词： Non-Newtonian fluids aeration process Power consumption Volumetric mass transfer rate Bubble size