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In situ modification of heavy oil catalyzed by nanosized metal-organic framework at mild temperature and its mechanism

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Chinese Journal of Chemical Engineering 2024年第3期67卷 166-173页

作者： Li Wang Ji-Xiang Guo Rui-Ying Xiong Chen-Hao Gao xiao-jun zhang Dan Luo The Unconventional Oil and Gas Institute China University of Petroleum-BeijingBeijing 102200China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Two catalysts, nano-sized cobalt-metal-organic framework(Co-MOF) and nickel(Ni)-MOF, were successfully prepared by the modification method. Tetralin(C10H12) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures(<300°C), leading to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was 0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280°C, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50°C from 15761.9 m Pa.s to 1266.2 m Pa.s,with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 m Pa.s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon-carbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

关键词： Nano-sized MOF Petroleum Viscosity reduction Catalyst Nanomaterials

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Geometric Error Identification of Gantry-Type CNC Machine Tool Based on Multi-Station Synchronization Laser Tracers

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 150-162页

作者： jun Zha Huijie zhang School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Xi’an Jiaotong University Suzhou Academy Suzhou 215123China

Laser tracers are a three-dimensional coordinate measurement system that are widely used in industrial *** propose a geometric error identification method based on multi-station synchronization laser tracers to enable the rapid and high-precision measurement of geometric errors for gantry-type computer numerical control(CNC)machine *** method also improves on the existing measurement efficiency issues in the single-base station measurement method and multi-base station time-sharing measurement *** consider a three-axis gantry-type CNC machine tool,and the geometric error mathematical model is derived and established based on the combination of screw theory and a topological analysis of the machine kinematic *** four-station laser tracers position and measurement points are realized based on the multi-point positioning principle.A self-calibration algorithm is proposed for the coordinate calibration process of a laser tracer using the Levenberg-Marquardt nonlinear least squares method,and the geometric error is solved using Taylor’s first-order linearization *** experimental results show that the geometric error calculated based on this modeling method is comparable to the results from the Etalon laser *** a volume of 800 mm×1000 mm×350 mm,the maximum differences of the linear,angular,and spatial position errors were 2.0μm,2.7μrad,and 12.0μm,respectively,which verifies the accuracy of the proposed *** research proposes a modeling method for the precise measurement of errors in machine tools,and the applied nature of this study also makes it relevant both to researchers and those in the industrial sector.

关键词： Multi-point positioning Multi-station synchronization CNC machine tool Geometric error Error separation

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Energy-efficient buffer and service rate allocation in manufacturing systems using hybrid machine learning and evolutionary algorithms

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Advances in Manufacturing 2024年第2期12卷 227-251页

作者： Si-xiao Gao Hui Liu jun Ota Key Laboratory of Traffic Safety on Track of Ministry of Education Institute of Artificial Intelligence and Robotics(IAIR)School of Traffic and Transportation EngineeringCentral South UniversityChangsha410075People’s Republic of China Research into Artifacts Center for Engineering School of EngineeringThe University of TokyoTokyoJapan

Currently,simultaneous buffer and service rate allocation is a topic of interest in the optimization of manufacturing *** allocation problems have been solved previously to satisfy economic requirements;however,owing to the progress of green manufacturing,energy conservation and environmental protection have become increasingly ***,an energy-efficient approach is developed to maximize the throughput and minimize the energy consumption of manufacturing systems,subject to the total buffer capacity,total service rate,and predefined energy *** energy-efficient approach integrates the simulated annealing-non-dominated sorting genetic algorithm-II with the honey badger algorithm-histogram-based gradient boosting regression *** former algorithm searches for Pareto-optimal solutions of sufficient *** latter algorithm builds prediction models to rapidly calculate the throughput,energy consumption,and energy *** examples show that the proposed hybrid approach can achieve a better solution quality compared with previously reported ***,the prediction models can rapidly evaluate manufacturing systems with sufficient *** study benefits the multi-objective optimization of green manufacturing systems.

关键词： Energy-efficient allocation Multi-objective optimization Energy efficiency Energy consumption Machine learning

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Mechanism of Ta on the microstructure and properties of Fe-Mn damping alloys

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Tungsten 2024年第4期6卷 767-777页

作者： Gui-Xiang Liu Kun zhang Chao Han xiao-Lin Shao jun Lu Lin zhang xiao-Song Jiang Zi-Xuan Wu Liu Yang The Second Sub-Institute Nuclear Power Institute of China Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiao tong University School of Engineering and Materials Science Queen Mary University of London Institute for Applied Materials (IAM-WK) Karlsruhe Institute of Technology (KIT)

Fe-Mn-Co-xTa alloys（x=0,1,2,3 wt.%） were fabricated using spark plasma sintering to explore the influence of Ta content on the microstructure,mechanical properties,and damping characteristics of Fe-17Mn-3Co damping *** micro structural analysis reveals the dominant presence of γ-austenite,ε-martensite,α'-martensite,and Co3Ta precipitates within the *** increments in Ta content exhibit proportional enhancements in hardness,tensile strength,and fracture elongation of the ***,these improvements in mechanical attributes are closely correlated with the generated second-phase *** the Ta content increases,there is a gradual augmentation in the formation of Co3Ta within the ***,the damping property initially experiences an ascent followed by a subsequent decline with rising Ta *** damping behavior finds its origins in multiple mechanisms,including grain boundary damping stemming from reduced grain size,interfacial damping induced by the generated Co3Ta,and dislocation *** is noteworthy that the emergence of the secondary phase wields a dual impact on damping *** the one hand,the proliferation of the second phase fosters increased interfaces for energy *** the other hand,these interfaces give rise to compressive stresses,constraining interface movement and thus impeding damping property enhancement.

关键词： Damping Fe–Mn–Co Mechanical properties Spark plasma sintering Ta

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Quantum state tomography from observable time traces in closed quantum systems

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Control Theory and Technology 2024年第2期22卷 222-234页

作者： Shuixin xiao Yuanlong Wang Qi Yu jun zhang Daoyi Dong Ian R.Petersen University of Michigan–Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai200240China School of Engineering The Australian National UniversityCanberraACT2601Australia Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China Centre for Quantum Computation and Communication Technology(Australian Research Council) Centre for Quantum DynamicsGriffith UniversityBrisbaneQLD4111Australia School of Engineering and Technology University of New South WalesCanberraACT2600Australia

The task to estimate all the parameters of an unknown quantum state, also called quantum state tomography, is essential for characterizing and controlling quantum systems. In this paper, we utilize observable time traces to identify the initial quantum state of a closed quantum system, based on the state space approach in the control theory. In the informationally complete scenario, we show that with a linear regression estimation (LRE), the mean squared error (MSE) scales as , where N is the resource number. In the informationally incomplete scenario, we introduce regularization LRE to perform the state tomography task. We employ PBH test to demonstrate that closed quantum systems with only one observable are informationally incomplete and propose using observables, where d is the dimension of the quantum state, for informational completeness. Numerical examples demonstrate the effectiveness of our method.

关键词： Quantum state tomography Time trace Quantum system identification

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The reservoir characteristics and their controlling factors of the sublacustrine fan in the Paleogene Dongying Formation, Bohai Sea,China

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Journal of Palaeogeography 2024年第1期13卷 127-148页

作者： xiao-jun Pang Guan-Min Wang Meng Zhao Qing-Bin Wang Xue-Fang zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Tianjin Branch of China National Offshore Oil Corporation Limited Tianjin 300459China

Sublacustrine fan is an important element in continental lacustrine basins and is significant for reservoir exploration. Oil and gas resources have been found in the sublacustrine fan sandstone reservoirs of the Paleogene Dongying Formation in the Bohai Sea. In this study, the characteristics of the sublacustrine fan reservoirs and the controlling factors are studied using information from logging, cores, physical properties,casting thin sections, X-ray diffraction of clay minerals, vitrinite reflectance, rock pyrolysis, manometry data,and 3D seismic data. The sublacustrine fans of the Dongying Formation in the LD10, QHD34, and BZ21 structures show high-quality reservoirs with porosity >15 % and permeability >5 m D. The main controlling factors of the high-quality reservoirs are attributed to the favorable sedimentary facies type and negligible compaction,and cementation, substantial dissolution of K-feldspar, overpressure, and the development of faults and fractures. A high-quality sublacustrine fan reservoir model has been established to explain how these factors affected the physical properties. The favorable targets for oil and gas exploration in the Dongying Formation of Bohai Sea include undercompacted sandy debris flow reservoirs showing the dissolution of K-feldspar, and the reservoirs which are connected to the source rocks by faults. This study provides insights to establish the relationship between sedimentology, diagenesis and reservoir quality. The results of this study are significant for the exploration and development of the sublacustrine fan sandstone reservoirs in the Bohai Sea and analogous sandstone reservoirs elsewhere.

关键词： Sublacustrine fan High-quality reservoir Dissolution Overpressure Fault Bohai Sea

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Physics of cavitation near particles

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Journal of Hydrodynamics 2024年第1期36卷 102-118页

作者： Jia-xin Yu xiao-yu Wang jun-wei Shen Jin-sen Hu Xiang-qing zhang Da-qing He Yu-ning zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

The combined effect of cavitation and silt abrasion presents a great challenge and threat to secure the operation and the efficiency of hydraulic machineries working in sediment-laden *** present paper critically reviews the current research progress on the interaction mechanisms of the bubbles and the ***,the analytical models including boundary treatment methods for predicting the jet dynamics of the bubble collapse near particles are ***,the bubble collapsing dynamics,jet dynamics and shock wave characteristics near particles are revealed both experimentally and ***,the bubble-particle-wall system is investigated with a focus on microjets.

关键词： Cavitation bubble particle jet shock wave

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Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

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Chinese Journal of Electronics 2024年第1期33卷 303-312页

作者： Tao zhang Ying FU jun zhang School of Computer Science and Technology Beijing Institute of Technology Advanced Reasearch Institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to conduct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Training Visualization Inverse problems Green products Noise reduction Pipelines Signal processing

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Triboelectric nanogenerators for self-powered neurostimulation

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Nano Research 2024年第10期17卷 8926-8941页

作者： Shumao Xu Farid Manshaii xiao xiao junyi Yin jun Chen Department of Bioengineering University of CaliforniaLos AngelesLos AngelesCA 90095USA

The burgeoning field of soft bioelectronics heralds a new dawn in medical treatment for neurological and psychiatric conditions,presenting innovative methods for the stimulation,inhibition,and precise sensing of neuronal *** to these advancements is the challenge of power supply;devices dependent on traditional batteries face limitations regarding miniaturization and require invasive surgeries for battery *** nanogenerators(TENGs),which generate power from biomechanical movements,offer a promising solution for developing self-powered neurostimulation devices without the need for an external power *** review delves into recent progress in TENGs,with a focus on their application in selfpowered neurostimulation *** utility of TENGs across various nervous systems—including the center,autonomic,and somatic nervous systems—is explored and presented,highlighting the potential for these devices to facilitate neurological *** summarizing TENGs’operational details and the potential for clinical translation,this review also identifies challenges associated with the implantation and integration of neural electrodes and presents recent advances in solutions,aiming to reshape electric treatments for neurological diseases.

关键词： triboelectric nanogenerators neurostimulation self-powered soft bioelectronics biomechanical energy harvesting

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Self-assembly of differentiated dental pulp stem cells facilitates spheroid human dental organoid formation and prevascularization

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World Journal of Stem Cells 2024年第3期16卷 287-304页

作者： Fei Liu Jing xiao Lei-Hui Chen Yu-Yue Pan jun-zhang Tian Zhi-Ren zhang xiao-Chun Bai School of Basic Medical Sciences Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of Health Management Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment Zhuhai People’s Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Centre of Reproduction Development and AgingFaculty of Health SciencesUniversity of MacaoMacao 999078China Department of Stomatology Guangdong Second Provincial General HospitalGuangzhou 510317Guangdong ProvinceChina Zhuhai Institute of Translational Medicine Zhuhai Hospital Affiliated with Jinan UniversityZhuhai 519000Guangdong ProvinceChina Department of Cell Biology School of Basic Medical SciencesSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

BACKGROUND The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative *** cells can self-organise into microsized organ units,partially modelling tissue function and *** pulp organoids have been used to recapitulate the processes of tooth development and related ***,the lack of vasculature limits the utility of dental pulp *** To improve survival and aid in recovery after stem cell transplantation,we demonstrated the three-dimensional(3D)self-assembly of adult stem cell-human dental pulp stem cells(hDPSCs)and endothelial cells(ECs)into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium(CM).METHODS During culture,primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and *** hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp *** biological characteristics of the organoids were analysed,and the regulatory pathways associated with angiogenesis were *** The combination of these two agents resulted in prevascularized human dental pulp organoids(Vorganoids)that more closely resembled dental pulp tissue in terms of morphology and ***-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with *** biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of *** In this innovative study,we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration,facilitating the development of clinical treatment strategies.

关键词： Human dental pulp stem cells Prevascularized organoids Integrated analyses Angiogenesis Forkhead box protein O1

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