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基于物理信息神经网络的盾构隧道诱发地表沉降预测

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工程力学 2024年第4期41卷 161-173页

作者：张子龙潘秋景仉文岗黄阜中南大学土木工程学院湖南长沙410075 中南大学隧地工程研究中心湖南长沙410075 重庆大学土木工程学院重庆400045 长沙理工大学土木工程学院湖南长沙410004

地表沉降是城市复杂环境下盾构隧道施工重点关注的问题。传统机器学习方法在预测隧道施工诱发地表沉降时忽略了其内在的物理机理,存在对训练样本需求量较大的弊端。基于深度神经网络(deep neural networks, DNN)对Verruijt-Booker解的... 详细信息

地表沉降是城市复杂环境下盾构隧道施工重点关注的问题。传统机器学习方法在预测隧道施工诱发地表沉降时忽略了其内在的物理机理,存在对训练样本需求量较大的弊端。基于深度神经网络(deep neural networks, DNN)对Verruijt-Booker解的围岩位移因子进行修正,构建地表沉降与隧道开挖面空间位置的关联。将修正后的Verruijt-Booker解的物理方程耦合至另一并行的DNN框架中,构建数据-物理双驱动的物理信息神经网络模型(physics-informed neural networks, PINN),从而约束神经网络在满足物理机制的空间中进行训练。算例分析的结果表明:在同等配置的条件下,提出的PINN模型的预测效果显著优于单一数据驱动的传统DNN模型,其外推泛化性能得到显著提升。工程应用的结果表明:PINN模型可以利用施工前期的实测数据,准确预测后续施工过程中开挖面在不同位置时监测断面的地表沉降值。提出的方法有助于提高盾构隧道施工过程中地表沉降控制的智慧化程度,可为工程的潜在风险及施工决策提供预警和指导。

关键词：盾构隧道地表沉降物理信息神经网络物理机理数据物理双驱动

Influence of excavation schemes on slope stability: A DEM study

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Journal of Mountain Science 2020年第6期17卷 1509-1522页

作者： WANG Zhen-yu GU Dong-ming zhang wen-gang Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China School of Civil Engineering Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China

Slope failure due to improper excavation is one of common engineering disasters in *** explore the failure mechanism of soil slope induced by toe excavation,especially to investigate the influence of excavation unloading path and rate on slope stability,a numerical slope model was built via particle flow code PFC2 *** development of crack and strain during excavation were obtained and used to evaluate the deformation ***,excavation types representing different unloading paths and rates were compared in terms of crack number and strain *** indicate that crack number and strain level induced by horizontal column excavation are much greater than those of vertical column excavation and oblique *** crack number and strain level increase with excavation unloading ***,the feasibility of taking the average strain of slope surface and the average value of maximum strain along monitoring lines to represent the global deformation characteristics were *** study can provide a theoretical guidance for slope monitoring and preliminary optimal selection of excavation scheme in the design and construction of slope engineering.

关键词： Slope toe excavation Unloading path Unloading rate Strain distribution Slope stability Discrete element method

Probabilistic stability analysis of embankment slopes considering the spatial variability of soil properties and seismic randomness

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Journal of Mountain Science 2022年第5期19卷 1464-1474页

作者： zhang wen-gang WU Jia-hao GU Xin HAN Liang WANG Lin School of Civil Engineering Chongqing UniversityChongqing 400045China

The safety of embankments under seismic conditions is a primary concern for geotechnical engineering *** reliability analysis approach offers an effective tool to quantify the safety margin of geotechnical structures from a probabilistic perspective and has gained increasing popularity in geotechnical *** study presents an approach for probabilistic stability analysis of embankment slopes under transient seepage considering both the spatial variability of soil parameters and seismic *** spatial varying soil parameters are firstly characterized by the random field theory,where a large number of random field samples of the soil parameters can be readily ***,the factor of safety(FS)of the embankment slope under seismic conditions corresponding to each random field sample is evaluated through performing seismic stability analysis based on the pseudo-static method.A hypothetical embankment example is adopted in this study for illustration,and the influences of shear strength parameters,seismic coefficient,and the external water level on the embankment slope failure probability are systematically *** show that the coefficient of variation of the friction angle and the horizontal scale of fluctuation have more significant effects on the embankment slope failure ***,the seismic coefficient also affects the embankment slope failure probability *** a given external water level,the failure probability corresponding to the downstream slope of the embankment is larger than that in the upstream slope.

关键词： Embankment Reliability analysis Spatial variability Seismic condition Pseudo-static method

Long-term outcomes of peroral endoscopic myotomy in achalasia patients with a minimum follow-up of 7 years

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Chinese Medical Journal 2020年第8期133卷 996-998页

作者： wen-gang zhang Ning-Li Chai Ya-Qi Zhai En-Qiang Linghu Hui-Kai Li Department of Gastroenterology Chinese People's Liberation Army General HospitalBeijing 100853China.

There was an enormous increase in reports confirming the safety and efficacy of using peroral endoscopic myotomy(POEM)to treat achalasia since the pioneering of the technique in 2010.[1]However,the reports focused on short to medium-term follow-ups,and data on long-term outcomes of POEM for achalasia were very *** still remains unknown whether the satisfactory short-term outcomes are long ***,some achalasia patients receiving POEM noted that they could benefit from post-operative dietary recommendations that would be helpful for symptom ***,this study aimed to determine the long-term treatment outcomes of using POEM to treat achalasia,and to assess postoperative Eckardt scores over this *** also crafted a set of post-POEM dietary recommendations according to the feedback from achalasia patients who underwent this treatment to achieve better symptom remission for post-POEM patients.

关键词： patients operative treatment

Total ionizing dose effect modeling method for CMOS digital-integrated circuit

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Nuclear Science and Techniques 2024年第2期35卷 32-46页

作者： Bo Liang Jin-Hui Liu Xiao-Peng zhang gang Liu wen-Dan Tan Xin-Dan zhang School of Computer Science and Technology Xidian UniversityXi’an 710071China

Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was *** digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional *** of these three parts was separately *** the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using *** the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area ***,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital *** experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose *** confirms the practicality and accuracy of the proposed modeling *** TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.

关键词： CMOS digital-integrated circuit Total ionizing dose IBIS model Behavior-physical hybrid model Physical parameters

Classification of knowledge graph completeness measurement techniques

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Journal of Systems Engineering and Electronics 2024年第1期35卷 154-162页

作者： zhang Ying XIAO gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and *** assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same ***,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge *** them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among *** this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness *** purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption

Formation of free-surface vortex and vortex suppression by rotating stopper-rod at end of tundish casting

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Journal of Iron and Steel Research International 2024年第5期31卷 1104-1116页

作者： Qing Fang Peng Zhao Hua zhang wen-hao Zhou gang Yu Jia-hui Wang Hong-wei Ni The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Hunan Valin Xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina

A rotating stopper-rod technique was proposed to suppress the formation of free-surface vortex in the *** large eddy simulation model coupled with volume of fluid model was developed to study the steel–slag–gas three-phase flow *** critical slag entrapment height of the free-surface vortex and mass of residual steel were predicted at different rotating speeds(30,60,90 and 120 r/min)of the rotating *** numerical model was verified by water model *** results showed that by rotating the stopper-rod in the opposite direction of the vortex above the submerged entry nozzle,the formation of vortex can be effectively disturbed and the critical height of the free-surface vortex can be *** for the 2nd strand,when the rotating speeds are 30,60,90 and 120 r/min,the critical height of the free-surface vortex above the 2nd strand is 7.3,4.7,6.3 and 7.4 cm,respectively.A reasonable rotating speed should be 60 r/min,which can reduce about 2 tons of residual *** rotating speeds just can reduce about 1.6 tons of residual steel.

关键词： Tundish Free-surface vortex Stopper-rod Numerical simulation Multiphase flow

Nanophononic metamaterials induced proximity effect in heat flux regulation

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Frontiers of physics 2024年第2期19卷 149-156页

作者： Jian zhang Haochun zhang gang zhang School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of High Performance Computing Agency for ScienceTechnology and Research(A*STAR)Singapore 138632Singapore

Recent studies have shown that the construction of nanophononic metamaterials can reduce thermal conductivity without affecting electrical properties,making them promising in many fields of application,such as energy conversion and thermal ***,although extensive studies have been carried out on thermal conductivity reduction in nanophononic metamaterials,the local heat flux characteristic is still *** this work,we construct a heat flux regulator which includes a silicon nanofilm with silicon *** regulator has remarkable heat flux regulation ability,and various impacts on the regulation ability are ***,even in the region without nanopillars,the local heat current is still lower than that in pristine silicon nanofilms,reduced by the neighboring nanopillars through the thermal proximity *** combine the analysis of the phonon participation ratio with the intensity of localized phonon modes to provide a clear *** findings not only provide insights into the mechanisms of heat flux regulation by nanophononic metamaterials,but also will open up new research directions to control local heat flux for a broad range of applications,including heat management,thermoelectric energy conversion,thermal cloak,and thermal concentrator.

关键词： nanophononic metamaterials proximity effect

Autophagy and its role in gastrointestinal diseases

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World Journal of Gastroenterology 2024年第36期30卷 4014-4020页

作者： Bo-Zong Shao wen-gang zhang Zhen-Yu Liu En-Qiang Linghu Department of Gastroenterology First Medical Center of Chinese People’s Liberation Army General HospitalBeijing 100853China

Gastrointestinal disorders encompass a spectrum of conditions affecting various organs within the digestive system,such as the esophagus,stomach,colon,rectum,pancreas,liver,small intestine,and bile *** role of autophagy in the etiology and progression of gastrointestinal diseases has garnered significant *** paper seeks to evaluate the impact and mechanisms of autophagy in gastrointestinal disorders by synthesizing recent research ***,we delve into inflammation-related gastrointestinal conditions,including ulcerative colitis,Crohn’s disease,and pancreatitis,as well as gastrointestinal cancers such as esophageal,gastric,and colorectal ***,we provide commentary on a recent publication by Chang et al in the World Journal of *** objective is to offer fresh perspectives on the mechanisms and therapeutic approaches for these gastrointestinal *** review aims to offer new perspectives on the mechanisms and therapeutic strategies for gastrointestinal disorders by critically analyzing relevant *** discussed,the role of autophagy in gastrointestinal diseases is complex and,at times,*** harness the full therapeutic potential of autophagy in treating these conditions,more in-depth research is imperative.

关键词： Autophagy Inflammation Cancer Inflammatory bowel disease Pancreatitis