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Deep-Learning-Based Production Decline Curve Analysis in the Gas Reservoir through Sequence Learning Models

Computer Modeling in Engineering & Sciences 2022年第6期130卷 1579-1599页

作者： Shaohua Gu Jiabao Wang Liang Xue Bin Tu Mingjin Yang Yuetian Liu State Key Laboratory of Shale Oil and Gas Enrichment mechanisms and Effective Development Beijing100083China Sinopec Petroleum Exploration and Production Research Institute Beijing100083China Department of Oil-Gas Field Development Engineering College of Petroleum EngineeringChina University of PetroleumBeijing102249China

Production performance prediction of tight gas reservoirs is crucial to the estimation of ultimate recovery,which has an important impact on gas field development planning and economic *** to the model’s simplicity,the decline curve analysis method has been widely used to predict production *** advancement of deep-learning methods provides an intelligent way of analyzing production performance in tight gas *** this paper,a sequence learning method to improve the accuracy and efficiency of tight gas production forecasting is *** sequence learning methods used in production performance analysis herein include the recurrent neural network(RNN),long short-term memory(LSTM)neural network,and gated recurrent unit(GRU)neural network,and their performance in the tight gas reservoir production prediction is investigated and *** further improve the performance of the sequence learning method,the hyperparameters in the sequence learning methods are optimized through a particle swarm optimization algorithm,which can greatly simplify the optimization process of the neural network model in an automated *** show that the optimized GRU and RNN models have more compact neural network structures than the LSTM model and that the GRU is more efficiently *** predictive performance of LSTM and GRU is similar,and both are better than the RNN and the decline curve analysis model and thus can be used to predict tight gas production.

关键词： Tight gas production forecasting deep learning sequence learning models

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Geometric Design-based Dimensional Synthesis of a Novel Metamorphic Multi-fingered Hand with Maximal Workspace

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 211-225页

作者： Wei An Jun Wei Xiaoyu Lu Jian S.Dai Yanzeng Li MOE Key Laboratory for Mechanism Theory and Equipment Design International Centre for Advanced Mechanisms and RoboticsTianjin UniversityTianjinChina Advanced Kinematics and Reconfigurable Robotics Lab School of Natural and Mathematical SciencesKing’s College LondonLondonUK Rutgers The State University of New JerseyNew BrunswickNew JerseyUSA

Current research on robotic dexterous hands mainly focuses on designing new finger and palm structures,as well as developing smarter control *** the dimensional synthesis of dexterous hands with traditional rigid palms has been carried out,research on the dimensional synthesis of dexterous hands with metamorphic palms remains *** study investigated the dimensional synthesis of a palm of a novel metamorphic multi-fingered hand,and explored the geometric design for maximizing the precision manipulation *** indexes were used to value the workspace of the metamorphic hand,and the best proportions between the five links of the palm to obtain the optimal workspace of the metamorphic hand were *** on the fixed total length of the palm member,four nondimensional design parameters that determine the size of the palm were introduced;through the discretization method,the influence of the four design parameters on the workspace of the metamorphic hand with full-actuated fingers and under-actuated fingers was *** on the analysis of the metamorphic multi-fingered hand,the symmetrical structure of the palm was designed,resulting in the largest workspace of the multi-fingered hand,and proved that the metamorphic palm has a massive upgrade for the workspace of underactuated *** research contributed to the dimensional synthesis of metamorphic dexterous hands,with practical significance for the design and optimization of novel metamorphic hands.

关键词： Metamorphic hands Dimensional synthesis Maximal workspace Discretization

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Bifurcation analysis of dual-sidestay landing gear locking performance considering joint clearance

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Chinese Journal of Aeronautics 2022年第7期35卷 209-226页

作者： Kui XU Yin YIN Yixin YANG Hong NIE Xiaohui WEI State Key Laboratory of Mechanics and Control of Mechanical structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Sidestay lock mechanism is an important part of landing gear system,and the locking performance can be analyzed based on changes in its ***,during numerical continuation analysis of fully-rigid dual-sidestay landing gear without clearance,it has been found that the appearance of bifurcation points does not necessarily imply that both sidestay links can be locked *** problem reveals the limitations of fully-rigid model with ideally-articulated in solving dual-sidestay mechanisms with extremely high motion ***,this study proposes a bifurcation analysis method for synchronous locking of dual-sidestay landing gears,which takes into consideration the joint *** in-depth analysis of this problem,we initially build kinematic and mechanical models of a landing gear mechanism that consider joint ***,the models are solved based on *** fundamental causes of synchronous locking are discussed in detail,and the number of bifurcation points is found to be closely related to whether the landing gear is completely ***,the effects of structural parameters on the synchronous locking are analyzed,and the feasible region of parameters satisfying synchronous locking condition is given,which agrees well with the test results.

关键词： Bifurcation Clearance Dual-sidestay landing gear Numerical continuation Synchronous locking

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Stabilizing mechanism of single-atom catalysts on a defective carbon surface

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npj Computational Materials 2020年第1期6卷 1469-1476页

作者： Lianping Wu Shuling Hu Wenshan Yu Shengping Shen Teng Li Department of Mechanical Engineering University of MarylandCollege ParkMD 20742USA State Key Laboratory for Strength and Vibration of Mechanical structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Single-atom(SA)catalysts represent the ultimate limit of atom use efficiency for *** experimental progress in synthesizing SA catalysts aside,the atomic-scale transformation mechanism from metal nanoparticles(NPs)to metal SAs and the stabilization mechanism of SA catalysts at high temperature remain *** systematic molecular dynamics simulations,for the first time,we reveal the atomic-scale mechanisms associated with the transformation of a metal NP into an array of stable SAs on a defective carbon surface at a high temperature,using Au as a model *** reveal the pivotal role of defects in the carbon surface in trapping and stabilizing the Au-SAs at high temperatures,which well explain previous experimental ***,reactive simulations demonstrate that the thermally stable Au-SAs exhibit much better catalyst activity than Au-NPs for the methane oxidation at high temperatures,in which the substantially reduced energy barriers for oxidation reaction steps are the *** in this study offer mechanistic and quantitative guidance for material selection and optimal synthesis conditions to stabilize metal SA catalysts at high temperatures.

关键词： material mechanism steps

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The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

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Journal of Advanced Ceramics 2021年第5期10卷 885-932页

作者： Hongcheng YANG Shuren ZHANG Hongyu YANG Qingyu WEN Qiu YANG Ling GUI Qian ZHAO Enzhu LI National Engineering Research Center of Electromagnetic Radiation Control Materials University of Electronic Science and Technology of ChinaChengdu 610054China Key Laboratory of Multi-Spectral Absorbing Materials and structures of Ministry of Education University of Electronic Science and Technology of ChinaChengdu 610054China

The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization *** review provides the summary of the study of microwave dielectric ceramics(MWDCs)sintered higher than 1000℃ from 2010 up to now,with the purpose of taking a broad and historical view of these ceramics and illustrating research *** date,researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric *** are variety of factors that impact the permittivity,dielectric loss,and temperature stability of dielectric materials,covering intrinsic and extrinsic *** of these factors are often intertwined,which can complicate new dielectric material discovery and the mechanism *** of the various ceramics systems,pseudo phase diagram was used to classify the dielectric materials based on the *** this review,the ceramics were firstly divided into ternary systems,and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was ***,some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method,characterization techniques,and significant theory developments.

关键词： high-temperature microwave dielectric ceramics(MWDCs) pseudo phase diagram developments and challenges composition-structure-property relationship

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Progressive Crushing of Polymer Matrix Composite Tubular structures: Review

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Open Journal of Composite Materials 2017年第1期7卷 14-48页

作者： Ali Rabiee Hessam Ghasemnejad Centre for structures Assembly and Intelligent Automation Cranfield University Cranfield UK

The present paper reviews crushing process of fibre-reinforced polymer (FRPs) composites tubular structures. Working with anisotropic material requires consideration of specific parameter definition in order to tailor a well-engineered composite structure. These parameters include geometry design, strain rate sensitivity, material properties, laminate design, interlaminar fracture toughness and off-axis loading conditions which are reviewed in this paper to create a comprehensive data base for researchers, engineers and scientists in the field. Each of these parameters influences the structural integrity and progressive crushing behaviour. In this extensive review each of these parameters is introduced, explained and evaluated. Construction of a well-engineered composite structure and triggering mechanism to strain rate sensitivity and testing conditions followed by failure mechanisms are extensively reviewed. Furthermore, this paper has mainly focused on experimental analysis that has been carried out on different types of FRP composites in the past two decades.

关键词： Crashworthiness Fibre-Reinforced Polymer Composites (FRPs) Metal Tube

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Electrospun carbon nanofibre-assisted patterning of metal oxide nanostructures

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Microsystems & Nanoengineering 2022年第3期8卷 263-276页

作者： Monsur Islam Christian Dolle Ahsana Sadaf Peter G.Weidler Bharat Sharma Yolita M.Eggeler Dario Mager Jan G.Korvink Institute of Microstructure Technology Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Microscopy of Nanoscale structures&mechanisms(MNM) Laboratory for Electron Microscopy(LEM)Karlsruhe Institute of TechnologyEngesserstr.7D-76131 KarlsruheGermany Institut fur Funktionlle Grenzflachen Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany

This work establishes carbon nanofibre-mediated patterning of metal oxide nanostructures,through the combination of electrospinning and vapor-phase transport *** of a suitable precursor with subsequent carbonization results in the patterning of catalyst gold nanoparticles embedded within carbon *** vapor-phase transport growth,these nanofibres allow preferential growth of one-dimensional metal oxide nanostructures,which grow radilly outward from the nanofibril axis,ielding a hairy caterpilr-ike *** synthesis of metal oxide caterpilars is demonstrated using zinc oxide,indium oxide,and tin *** and substrate temperatures play the most crucial role in determining the morphology of the metal oxide caterpillars,whereas the distribution of the nanofibres also has a significant impact on the overall *** the current methodology with near-field electrospinning further facilitates user-defined custom patterning of metal oxide caterpllr-like structures.

关键词： fibre carbon patterning

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Mechanism and control of the long-term performance evolution of structures

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Frontiers of Structural and Civil Engineering 2020年第5期14卷 1039-1048页

作者： Zhiqiang DONG Gang WU Hong ZHU Haitao WANG Yihua ZENG Key Laboratory of Concrete and Prestressed Concrete structures of Ministry of Education Southeast UniversityNanjing 210096China National and Local Joint Engineering Research Center for Intelligent Construction and Maintenance Nanjing 210096China College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China

It is well known that structural properties degrade under long-term environmental exposure and loading and that the degradation rate is controlled by inherent physical and chemical degradation *** elucidation of the degradation mechanisms and the realization of effective long-term performance degradation control have been a research frontier in the field of civil engineering in recent ***,the major topics that concern this research frontier include revealing the physical and chemical mechanisms of structural performance evolution under long-term environmental exposure and loading and developing structural performance degradation control technologies based on fiber-reinforced materials,for example,fiber-reinforced polymers(FRPs)and fabric-reinforced cementitious matrix(FRCM).In addition,there are novel structural performance control technologies,such as using a shape memory alloy(SMA)and self-healing *** paper presents a brief state-of-the-art review of this topic,and it is expected to provide a reference for subsequent research.

关键词： degradation mechanism performance evaluation strengthening FRP FRCM

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Effects of twin orientation and twin boundary spacing on the plastic deformation behaviors in Ni nanowires

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Journal of Materials Science & Technology 2023年第4期135卷 231-240页

作者： Ying Zhang Yuxuan Hou He Zheng Ligong Zhao Shuangfeng Jia Kaixuan Li Huayu Peng Peili Zhao Lei Li Weiwei Meng Renhui Jiang Jianbo Wang School of Physics and Technology Center for Electron MicroscopyMOE Key Laboratory of Artificial Micro-and Nano-structures and Institute for Advanced StudiesWuhan UniversityWuhan 430072China Suzhou Institute of Wuhan University Suzhou 215123China Wuhan University Shenzhen Research Institute Shenzhen 518057China

Spreading twins throughout nano metals has been proved to effectively mediate the mechanical behaviors in face-centered-cubic(fcc)***,the experimental investigation concerning the roles of twin boundary(TB)during deformation is rarely ***,with the joint efforts of in-situ nanomechani-cal testing and theoretical studies,we provide a systematic investigation regarding the effects of TB orien-tation(θ,the angle between tensile loading direction and the normal of TB)and spacing on deformation mechanisms in Ni nanowires(NWs).As compared with single-crystalline counterparts,it is found that nano-twinned(nt)NWs withθ∼0°exhibit limited ductility,whereas TB can serve as an effective block-age to the dislocation *** contrast,in nt NWs withθ∼20°and 55°,TB migration/detwinning induced by TB-dislocation reaction or partial dislocation movement dominates the plasticity,which con-tributes to enhanced NW *** nt NWs withθ∼90°,dislocations are found to be able to transmit through the TBs,suggesting the limited effect of TB on the NW ***,de-creasing TB spacing(λ)can facilitate the detwinning process and thus greatly enhance the ductility of NW withθ∼55°.This study uncovers the distinct roles that TB can play during mechanical deforma-tions in fcc NWs and provides an atomistic view into the direct linkage between macroscopic mechanical properties and microscopic deformation modes.

关键词： In-situ tension test Twin orientation Twin boundary migration Ductility Nano-twinned Ni nanowires

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The race to the nociceptor: mechanical versus temperature effects in thermal pain of dental neurons

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Acta Mechanica Sinica 2017年第2期33卷 260-266页

作者： Min Lin Fusheng Liu Shaobao Liu Changchun Ji Ang Li Tian Jian Lu Feng Xu The Key Laboratory of Biomedical Information Engineering of the Ministry of Education School of Life Science and Technology Xi’an Jiaotong University Xi’an 710049 China Bioinspired Engineering and Biomechanics Center (BEBC) Xi’an Jiaotong University Xi’an 710049 China State Key Laboratory for Strength and Vibration of Mechanical structures Xi’an Jiaotong UniversityXi’an 710049 China MOE Key Laboratory for Multifunctional Materials and structures Xi’an Jiaotong University Xi’an 710049 China Department of Acupuncture Shaanxi Hospital of Traditional Chinese Medicine Xi’an 710003 China Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of Stomatology Xi’an Jiaotong University Xi’an 710049 China

The sensing of hot and cold stimuli by dental neurons differs in several fundamental ways. These sensations have been characterized quantitatively through the measured time course of neural discharge signals that result from hot or cold stimuli applied to the teeth of animal models. Although various hypotheses have been proposed to explain the underlying mechanism, the ability to test competing hypotheses against experimental recorded data using biophysical models has been hindered by limitations in our understanding of the specific ion channels involved in nociception of dental neurons. Here we apply recent advances in established biophysical models to test the competing hypotheses. We show that a sharp shooting pain sensation experienced shortly following cold stimulation cannot be attributed to the activation of thermosensitive ion channels, thereby falsifying the so-called neuronal hypothesis, which states that rapidly transduced sensations of coldness are related to thermosensitive ion channels. Our results support a central role of mechanosensitive ion channels and the associated hydrodynamic hypothesis. In addition to the hydrodynamic hypothesis, we also demonstrate that the long time delay of dental neuron responses after hot stimulation could be attributed to the neuronal hypothesis-that a relatively long time is required for the temperature around nociceptors to reach some threshold. The results are useful as a model of how multiphysical phenomena can be combined to provide mechanistic insight into different mechanisms underlying pain sensations.

关键词： Thermomechanics Dentinal fluid flow Dental neuron Neural discharge pattern Time delay

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