检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1229-1245页

作者： SHANG Minggang FENG Qiong ZHANG Yunsheng HE Zhongmao QIAO Hongxia XUE Cuizhen WANG Jinpen HAN Yuehui School of civil Engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Advanced civil Engineering Materials Engineering Research Center Lanzhou 730050China college of Science&Technology Ningbo UniversityNingbo 315211China

Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength,axial compressive strength,flexural strength,microhardness,total number of pores,pore area,and pore *** results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens,whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical *** analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration,resulting in a denser microstructure than that of ordinary *** results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25%MSWIT-LA was superior to that of an equivalent ordinary *** was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources.

关键词： municipal solid waste incineration tailings X-ray computed tomography lightweight aggregate microhardness principal component analysis

An extended micromechanical-based plastic damage model for understanding water effects on quasi-brittle rocks

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第3期34卷 289-304页

作者： Qiaojuan Yu Shigui Du Qizhi Zhu Zhanyou Luo Sili Liu Lunyang Zhao Institute of Rock Mechanics Ningbo UniversityNingbo 315211China Ningbo Key Laboratory of Energy Geostructure Ningbo UniversityNingbo 315211China college of civil and Transportation Engineering Hohai UniversityNanjing 210098China college of civil Engineering Jiangsu Open UniversityNanjing 210036China South China Institution of Geotechnical Engineering School of Civil Engineering and TransportationSouth China University of TechnologyGuangzhou 510641China

Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical ***,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of *** this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics *** the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock *** proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental *** model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.

关键词： Water Micro-crack Damage Micro-mechanics Constitutive model Cohesive force

Factors affecting college students’attitudes towards carpooling

在线全文

学校读者我要写书评

暂无评论

Transportation Safety and Environment 2024年第2期6卷 55-62页

作者： Linchao Li Huali Zhang Zuoxian Gan college of civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China college of Transportation Engineering Dalian Maritime UniversityDalian 116026LiaoningChina

As a sustainable mode of travel,carpooling is an effective solution to environmental and energy problems,but it has not been fully *** research on carpooling attitudes,especially for college students,still needs to be *** response to this problem,this paper aims to investigate the effect of personal attributes,travel attributes,attitude attributes and other attributes of students on carpooling attitudes in *** collect the data,an online questionnaire survey was implemented at Shenzhen University,and 514 students *** on the samples,the multinomial logit model is used to explore the contribution of all *** model results showed that personal attributes such as sex and age had no significant effect on the attitude of college students towards *** safety of carpooling and its high cost make college students have a neutral attitude towards *** most concerning factor for college students in carpooling is *** findings can provide valuable suggestions for measures to be taken in response to different attributes affecting students’attitudes and are particularly important for the university and government to make optimal decisions to motivate students to select carpooling.

关键词： carpooling attitudes college students multinomial logit traffic environment

Hollow cathode effect in radio frequency hollow electrode discharge in argon

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 496-502页

作者：贺柳良何锋欧阳吉庭 college of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China School of Physics Beijing Institute of TechnologyBeijing 100081China

Radio frequency capacitively coupled plasma source(RF-CCP)with a hollow electrode can increase the electron density through the hollow cathode effect(HCE),which offers a method to modify the spatial profiles of the plasma *** this work,the variations of the HCE in one RF period are investigated by using a two-dimensional particle-in-cell/Monte-Carlo collision(PIC/MCC)*** results show that the sheath electric field,the sheath potential drop,the sheath thickness,the radial plasma bulk width,the electron energy distribution function(EEDF),and the average electron energy in the cavity vary in one RF *** the hollow electrode sheath's expansion phase,the secondary electron heating and sheath oscillation heating in the cavity are gradually enhanced,and the frequency of the electron pendular motion in the cavity gradually increases,hence the HCE is gradually ***,during the hollow electrode sheath's collapse phase,the secondary electron heating is gradually *** addition,when interacting with the gradually collapsed hollow electrode sheaths,high-energy plasma bulk electrons in the cavity will lose some ***,the frequency of the electron pendular motion in the cavity gradually ***,during the hollow electrode sheath's collapse phase,the HCE is gradually attenuated.

关键词： hollow cathode effect radio frequency hollow electrode particle-in-cell/Monte-Carlo collision(PIC/MCC)model

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

在线全文

学校读者我要写书评

暂无评论

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

Infiltration,runoff,and slope stability behaviors of infinite slope with macropores based on an improved Green–Ampt model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第7期21卷 2220-2235页

作者： LI Shanghui WU Guoxiong QUE Yun JIANG Zhenliang CHENG Gaoyun college of Intelligent Construction Fuzhou University of International Studies and TradeFuzhou 350202China college of civil Engineering Chongqing Jiao Tong UniversityChongqing 400074China Chongqing Vocational college of Architectural Engineering Chongqing 400072China college of civil Engineering Fuzhou UniversityFuzhou 350000China Department of civil and Environmental Engineering Hong Kong University of Science and TechnologyHong Kong 999077China T.Y.Lin International Engineering Consulting(China)Co.Ltd Chongqing 401120China

Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is *** paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation *** show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative *** wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall ***,macropores benefit the slope stability in the early rainfall but not in the *** flow does not occur initially but becomes pronounced with increasing rainfall *** equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore *** analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows ***,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.

关键词： Macropore slope Green–Ampt infiltration model Equivalent wetting front Ponding response time Slope stability

The Analysis of the Correlation between SPT and CPT Based on CNN-GA and Liquefaction Discrimination Research

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第2期138卷 1159-1182页

作者： Ruihan Bai Feng Shen Zihao Zhao Zhiping Zhang Qisi Yu Key Laboratory of the Ministry of Education for Geomechanics and Embankment Engineering College of Civil and Transportation EngineeringHohai UniversityNanjing210098China School of civil Engineering Suzhou University of Science and TechnologySuzhou215011China School of civil Engineering Shenyang Jianzhu UniversityShenyang110168China college of civil Engineering Tongji UniversityShanghai200092China

The objective of this study is to investigate themethods for soil liquefaction discrimination. Typically, predicting soilliquefaction potential involves conducting the standard penetration test (SPT), which requires field testing and canbe time-consuming and labor-intensive. In contrast, the cone penetration test (CPT) provides a more convenientmethod and offers detailed and continuous information about soil layers. In this study, the feature matrix based onCPT data is proposed to predict the standard penetration test blow count N. The featurematrix comprises the CPTcharacteristic parameters at specific depths, such as tip resistance qc, sleeve resistance f s, and depth H. To fuse thefeatures on the matrix, the convolutional neural network (CNN) is employed for feature extraction. Additionally,Genetic Algorithm (GA) is utilized to obtain the best combination of convolutional kernels and the number ofneurons. The study evaluated the robustness of the proposed model using multiple engineering field data *** demonstrated that the proposed model outperformed conventional methods in predicting N values forvarious soil categories, including sandy silt, silty sand, and clayey silt. Finally, the proposed model was employedfor liquefaction discrimination. The liquefaction discrimination based on the predicted N values was comparedwith the measured N values, and the results showed that the discrimination results were in 75% agreement. Thestudy has important practical application value for foundation liquefaction engineering. Also, the novel methodadopted in this research provides new ideas and methods for research in related fields, which is of great academicsignificance.

关键词： CNN liquefaction discrimination SPT CPT

Catalytic upgrading biomass-derived ethanol and acetic acid into C4 chemicals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3588-3613页

作者： Tingting Yan Mengting Zhang Runzhi Yuan Weili Dai college of Science Civil Aviation University of China School of Materials Science and Engineering & National Institute for Advanced Materials Nankai University

Synthesis of value-added chemicals from biomass is an essential strategy to mitigate the global dependency on fossil resources and achieve the aim of carbon neutrality. Thereinto, ethanol and acetic acid are crucial biomass-derived platform ***, catalytic upgrading ethanol and acetic acid into C4 energy-intensive fuels and chemicals via the elongation of carbon backbone has received widespread attention. The primary focus of this review is to systematically describe the recent breakthrough in the conversion of ethanol or acetic acid to C4 chemicals including 1,3-butadiene, n-butenes, isobutene or *** attentions will be given to heterogeneous catalyst design strategies, reaction parameters on the catalytic performance along with the relevant mechanism investigations, as well as their future challenges and opportunities. The present review will provide the detailed insights into the synthesis of C4 chemicals from biomass-derived ethanol and acetic acid and shed a light on the development of highly efficient catalysts.

关键词： ethanol acetic acid C4 chemicals catalytic upgrading aldol condensation

Quantitative characterization of fusion state of virgin and aged asphalt using nano-ferrous ferric oxide tracer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 467-480页

作者： Qiang Li Song Liu Huameng Wen Zhou Zhou college of civil Engineering Nanjing Forestry UniversityNanjing 210037China School of Transportation Southeast UniversityNanjing 211189China

The exact evaluation of the fusion rate of virgin and aged asphalt is essential to optimize the performance of the recycled asphalt *** fusion rate index was developed by tracing the distribution of tracer asphalt,which contains nano-ferrous ferric oxide(nano-Fe_(3)O_(4))*** fusion simulation tests were performed on three types of asphalt to obtain different fusion states,and fatigue tests were performed to evaluate the influence of the fusion rate on the fatigue life of the recycled *** was found that the tracer asphalt containing 4%nano-Fe_(3)O_(4)shows the optimal trace effect,and the developed fusion rate index can quantitatively characterize the influence of different factors on the fusion state of the recycled *** fusion state is closely related to the fatigue performance of recycled asphalt,and the fusion rate index can fairly evaluate its fatigue *** relationship between the fusion rate and the fatigue life of recycled asphalt depends on the factors that cause the fusion rate *** the influence of the amount of rejuvenator,the fatigue life of recycled asphalt grows exponentially with increasing fusion rate due to enhancement of molecular motion as well as a supplement of lightweight *** the influence of heat preservation treatment,fatigue life increases linearly with increasing fusion *** proposed fusion rate index can be utilized to quantitatively characterize the fusion state of virgin and aged asphalt,thus providing a simple way to guide the practical application of recycled asphalt.

关键词： Recycled asphalt Rejuvenator Tracing technique Fusion rate Fatigue

Fluid-solid coupling numerical simulation of micro-disturbance grouting treatment for excessive deformation of shield tunnel

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第6期19卷 87-100页

作者： Yanjie Zhang Zheng Cao Chun Liu Hongwei Huang college of civil Engineering and Architecture Henan University of TechnologyZhengzhou 450001China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Micro-disturbance grouting is a recovery technique to reduce the excessive deformation of operational shield tunnels in urban *** grout mass behaves as a fluid in the ground before hardening to form a grout–soil mixture,which highlights the necessity of using fluid–solid coupling method in the simulation of grouting *** a discrete element modeling environment,this paper proposes a novel fluid-solid coupling method based on the pore density flow *** demonstrate the effectiveness of this method,it is applied to numerical simulation of micro-disturbance grouting process for treatment of large transverse deformation of a shield tunnel in Shanghai Metro,*** simulation results reveal the mechanism of recovering tunnel convergence by micro-disturbance grouting in terms of compaction and fracture of soil,energy analysis during grouting,and mechanical response of soil-tunnel interaction ***,the influence of the three main grouting parameters(i.e.,grouting pressure,grouting distance,and grouting height)on tunnel deformation recovery efficiency is evaluated through parametric *** order to efficiently recover large transverse deformation of shield tunnel in Shanghai Metro,it is suggested that the grouting pressure should be about 0.55 MPa,the grouting height should be in the range of 6.2–7.0 m,and the grouting distance should be in the range of 3.0–3.6 *** results provide a valuable reference for grouting treatment projects of over-deformed shield tunnel in soft soil areas.

关键词： Fluid-solid coupling Discrete element method Pore density flow Micro-disturbance grouting Soil-tunnel interaction