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Effect of pipe installation and external load on buried steel pipe responses:Experimental and numerical investigations

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Underground Space 2024年第2期15卷 44-58页

作者： Yadong zhang Ron Chik-Kwong Wong Jianfeng Chen Wei su Department of Civil Engineering Schulich School of EngineeringUniversity of CalgaryCalgaryAB T2N 1N4Canada Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

During pipe installation,compacting soil at pipe sides causes an initial pipe deformation which is known as the"peaking"***,in conventional pipe design codes,only pipe deformation caused by vertical overburden is considered while the"peaking"effect is *** this study,a full-scale test was conducted on a Grade X52 steel pipe with a diameter of 600 mm to investigate the impacts of both soil compaction and vertical overburden on pipe *** compaction and external load were found to elongate and shorten the vertical pipe diameter,***"peaking"effect was observed during the installation procedure accompanied by the highest pipe stress measured at the pipe ***,a two-dimensional finite element model was created and validated based on the calculated pipe stresses from the experimental study.A parametric study was performed thereafter to numerically study the impacts of soil water content,pipe wall thickness,compaction pressure,and lift thickness on pipe responses due to soil compaction and external *** increase in the"peaking"effect is observed with increasing soil water content and compaction pressure,while an increase in pipe wall thickness or lift thickness would cause a decrease in the"peaking"effect.

关键词： X52 steel Soil compaction External load Peaking effect Pipe deflection Soil arching

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

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Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-Ming su jun-Gang Lu Jian Yu Zi-Xing Lu Shi-Jia Chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

Simple and effective:superlubricity behaviour of the G-quadruplex hydrogel with high selectivity for K+ions based on the ocular environment

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Friction 2024年第11期12卷 2548-2562页

作者： Hongdong WANG Jian WU Kunpeng WANG Yunjuan su Xiacong zhang Yuhong LIU Jianhua zhang School of Mechatronic Engineering and Automation and Key Laboratory of Advanced Display and System Application Ministry of EducationShanghai UniversityShanghai 200444China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

Hydrogels have been the subject of significant research in the field of friction due to their exceptional lubricating *** this study,the G-quadruplex hydrogel with high selectivity for K+ions was formed by introducing a mixture of G,2-formylphenylboronic acid,and polyethylene glycol diamine into simulated artificial tears solution with high transparency,and an ultra-low coefficient of friction(COF)of about 0.004 was obtained based on the simulated ocular environment,thus achieving macroscopic *** friction pairs simulating the ocular environment,to assess the frictional performance of the G-quadruplex hydrogel as both a lubricant and a friction pair based on the simulated ocular environment,we conducted experiments considering various factors such as concentration,sliding speed,and *** these experiments,it was found that superlubricity was achieved when the G-quadruplex hydrogel was applied as lubricant or friction *** effect was attributed to the three-dimensional network structure and hydrophilicity of the hydrogel,which facilitated the formation of a highly bearing and flowing hydration layer,promoting macroscopic *** to the G-quadruplex hydrogel with low concentration,the high concentration hydrogel(75 mM)exhibited increased mechanical strength and robustness in *** with biocompatibility experiments,our synthesized G-quadruplex hydrogel has excellent biocompatibility and offers a novel approach to achieve superlubricity in ocular drug delivery.

关键词： superlubricity ocular environment G-quadruplex hydrogel bio-compatibility

Molecular Mechanism and Molecular Design of Lubricating Oil Antioxidants

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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 135-145页

作者： su Shuo Long jun Duan Qinghua Zhou Han Zhao Yi SINOPEC Research Institute of Petroleum Processing Co.Ltd. Beijing 100083

To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established *** molecular mechanism of the antioxidant reaction of hindered phenol,diphenylamine,and alkyl sulfide are studied via molecular *** results show that the strong electron-donating ability and high hydrogen-donating activity of the antioxidant molecule and the low hydrogen-abstracting activity of free radicals formed after dehydrogenation are the internal molecular causes of the shielding of phenol and diphenylamine from scavenging peroxy free radicals,and the strong electron-donating ability is the internal molecular cause of the high activity of thioether in decomposing alkyl hydrogen *** on this antioxidant molecular mechanism,a molecular design rule of antioxidant is proposed,namely“high EHOMO,large Q(S),low bond dissociation energy BDE(O—H)and BDE(N—H)”.Two new antioxidants,PAS-I and PAS-II,are designed and prepared by chemical bonding of hindered phenol,diphenylamine,and sulfur *** results show that these antioxidants both have excellent antioxidant effects in lubricating oil,and that PAS-II is the superior antioxidant,consistent with theoretical predictions.

关键词： lubricating oil antioxidant molecular mechanism molecular design antioxidant performance

Analytical Models of on-Chip Hardware Trojan Detection Based on Radiated Emission Characteristics

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Chinese Journal of Electronics 2024年第2期33卷 385-392页

作者： Fan zhang Dongrong zhang Qiang REN Aixin CHEN Donglin su School of Electronics and Information Engineering Beihang University Zhongguancun Laboratory The Research Institute for Frontier Science Beihang University

Since many third parties involved in integrated circuit(IC) manufacturing, hardware Trojans malicious implantation have become a threat to the IC industry. Therefore, varieties of reliable hardware Trojan detection methods are needed. Since electromagnetic radiation is an inherent phenomenon of electronic devices, there are significant differences in the electromagnetic radiated characteristics for circuits with different structures and operating states. In this paper, a novel hardware Trojan detection method is proposed, which considers the electromagnetic radiation differences caused by hardware Trojan implantation. Experiments of detecting hardware Trojan in field programmable gate arrays show that the proposed method can effectively distinguish the ICs with Trojan from the ones without Trojan by the radiated emission.

关键词： Electromagnetic radiation Propagation losses Hardware System-on-chip Registers Manufacturing Trojan horses

Directly predicting N_(2) electroreduction reaction free energy using interpretable machine learning with non-DFT calculated features

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Journal of Energy Chemistry 2024年第10期97卷 139-148,I0004页

作者： Yaqin zhang Yuhang Wang Ninggui Ma jun Fan Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Center for Advanced Nuclear Safety and sustainable Development City University of Hong KongHong Kong 9077China Department of Mechanical Engineering City University of Hong KongHong Kong 999077China

Electrocatalytic nitrogen reduction to ammonia has garnered significant attention with the blooming of single-atom catalysts(SACs),showcasing their potential for sustainable and energy-efficient ammonia ***,cost-effectively designing and screening efficient electrocatalysts remains a *** this study,we have successfully established interpretable machine learning(ML)models to evaluate the catalytic activity of SACs by directly and accurately predicting reaction Gibbs free *** models were trained using non-density functional theory(DFT)calculated features from a dataset comprising 90 graphene-supported *** results underscore the superior prediction accuracy of the gradient boosting regression(GBR)model for bothΔg(N_(2)→NNH)andΔG(NH_(2)→NH_(3)),boasting coefficient of determination(R^(2))score of 0.972 and 0.984,along with root mean square error(RMSE)of 0.051 and 0.085 eV,***,feature importance analysis elucidates that the high accuracy of GBR model stems from its adept capture of characteristics pertinent to the active center and coordination environment,unveilling the significance of elementary descriptors,with the colvalent radius playing a dominant ***,Shapley additive explanations(SHAP)analysis provides global and local interpretation of the working mechanism of the GBR *** analysis identifies that a pyrrole-type coordination(flag=0),d-orbitals with a moderate occupation(N_(d)=5),and a moderate difference in covalent radius(r_(TM-ave)near 140 pm)are conducive to achieving high ***,we extend the prediction of activity to more catalysts without additional DFT calculations,validating the reliability of our feature engineering,model training,and design *** findings not only highlight new opportunity for accelerating catalyst design using non-DFT calculated features,but also shed light on the working mechanism of"black box"ML ***,the model provides valuable g

关键词： Nitrogen reduction Single-atom catalyst Interpretable machine learning Graphene Non-DFT features

Mesoporous molecular sieve confined phase change materials with high absorption,enhanced thermal conductivity,and cooling energy charging/discharging capacity

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Frontiers of Materials Science 2024年第1期18卷 1-14页

作者： Qi zhang Chongyang Liu Xuehong Wu Xueling zhang jun Song School of Energy and Power Engineering Zhengzhou University of Light IndustryZhengzhou 450007China

The biggest challenge for organic phase change materials(PCMs)used in cold energy storage is to maintain high heat storage capacity while reducing the leakage risk of PCMs during the phase transition *** is crucial for expanding their applications in the more demanding cold storage *** this study,novel formstable low-temperature composite PCMs are prepared with mesoporous materials,namely SBA-15 and CMK-3(which are prepared using the template method),as supporting matrices and dodecane as the *** to the combined effects of capillary forces within mesoporous materials and interactions among dodecane molecules,both dodecane/SBA-15 and dodecane/CMK-3 exhibit outstanding shape stability and thermal cycling stability even after 200 heating/cooling *** comparison to those of dodecane/SBA-15,dodecane/CMK-3 exhibits superior cold storage performance and higher thermal ***,the phase transition temperature of dodecane/CMK-3 is-8.81℃ with a latent heat of 122.4 J·g^(-1).Additionally,it has a thermal conductivity of 1.21 W·m^(-1)·K^(-1),which is 9.45 times that of dodecane *** these highlight its significant potential for applications in the area of cold energy storage.

关键词： cold energy storage phase change material mesoporous molecular sieve CMK-3 SBA-15 cooling energy charging/discharging capacity

Diminishing the Perception Bias in the Working Environment Using a Network Generation-Based Framework

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Tsinghua Science and Technology 2024年第3期29卷 671-683页

作者： jun Qian Tongda zhang Xiao sun Yueting Chai Department of Automation Tsinghua UniversityBeijing 100084China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055Chinaand with Systems Optimization LaboratoryStanford UniversityPalo AltoCA 94305USA

Income inequality is widespread in human society and has important implications for human ***’s perception of the environment bridges income inequality and individual behavioral *** research suggests that social income inequality is usually biased,either overestimated or ***,such phenomena have not been fully explored with quantitive prove,especially in the working environment based on performance data of actual *** fact,the correct perception of people is the basis of a fair environment for their production ***,the perception bias may weaken the adaptability and competitiveness of a company in the *** paper first confirms the prevalence of individual perception bias of income inequality within the working environment based on actual production *** results show that people tend to underestimate income inequity around them,and this underestimation grows with the real unfairness of the working ***,this paper proposes a network generation-based framework with a three-layer structure to correct perception bias using a cooperative network reengineering *** the framework,a homophily-based generative network model is proposed as the key *** simulation results show that our proposed framework effectively reduces individuals’perception bias of income inequality.

关键词： income inequality perception bias Gini coefficient factory production cooperative networkreengineering homophily-based generative network model

超高韧性水泥基材料增强框架节点抗震性能有限元分析

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世界地震工程 2016年第4期32卷 50-55页

作者：苏骏李威张晋湖北工业大学土木工程与建筑学院湖北武汉430068

为了研究超高韧性水泥基材料增强框架梁柱节点的抗震性能,采用Opensees有限元软件对3榀框架梁柱中节点进行了非线性有限元分析。通过调整混凝土本构模型中抗拉阶段的荷载-位移关系,模拟了超高韧性水泥基材料的应变硬化性能。计算得到了... 详细信息

为了研究超高韧性水泥基材料增强框架梁柱节点的抗震性能,采用Opensees有限元软件对3榀框架梁柱中节点进行了非线性有限元分析。通过调整混凝土本构模型中抗拉阶段的荷载-位移关系,模拟了超高韧性水泥基材料的应变硬化性能。计算得到了试件的滞回曲线、骨架曲线和能量耗散系数,并与试验结果进行了对比。两者吻合良好,表明所采用的材料本构关系和建立的非线性有限元模型能够较准确的模拟超高韧性水泥基材料增强框架节点的抗震性能。

关键词：超高韧性水泥基材料梁柱节点 Opensees 抗震性能非线性有限元分析