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Properties and Hydration Mechanism on High-strength Anchorage Grouting Material for Highway Slope

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Journal of Wuhan University of Technology(Materials Science) 2013年第6期28卷 1181-1185页

作者： TANG Hua LI Xiangguo ZHANG Fachun HE Chao TAN Hongbo FANG Rui State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of Sciences State Key Laboratory of Silicate Materials for Architectures (Wuhan University of Technology) National Engineering Laboratory for land transport Meteorological Disaster Control Technology

The rheological and mechanical properties of high-strength anchorage grouting materials for highway slope were investigated to optimize the mix proportion. The experimental results showed that the optimized mix proportion of high-strength anchorage grouting material （HAGM） was C3 （FA：SP-SF= 1：2：2; AGI：AG2=3：7 and 0.03% FC）, which is agreement with the limitation of JCT 986-2005. Moreover, the XRD and FTIR results showed the addition of expansive components was in favor of the formation of ettringite. The intensity of AFt oeak of the samnles increased with the increasing of hydration time.

关键词： grouting material fluidity strength hydration slope

Reviewing trip purpose imputation in GPS-based travel surveys

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Journal of Traffic and transportation Engineering(English Edition) 2020年第4期7卷 395-412页

作者： Minh Hieu Nguyen Jimmy Armoogum Jean-Loup Madre Cedric Garcia Universite Gustave Eiffel/AME/DEST Marne la ValleeF-77447France Faculty of transport Economics University of Transport and CommunicationsHanoiVietnam

The global positioning system(GPS)has motivated rapid advances in mobility data collection.A massive amount of spatio-temporal information has made it possible to know where a person was and when,but not how and why(s)he travelled,creating the need for inference *** with mode detection,purpose imputation has been insufficiently ***,the relative lack of attention to purpose identification does not mean that this field has not *** this paper,which is the first review dedicated to inferringtrip purposes from GPS data,1162 non-duplicate papers from four databases(Scopus,Web of Science,ScienceDirect and TRID)were screened,and a corpus of 25 publications was selected for *** on these papers,the purpose imputation problem is defined in the contexts of the evolution of GPS-based travel surveys and two research domains,transportation science(TS)and human geography(HG).Subsequently,three steps of the purpose detection process,namely trip end detection,input feature selection and main algorithms and validation,are *** these procedures,the differences between studies in TS and those in HG are ***,unresolved issues related to data and feature selection,algorithms and assessment are discussed substantially to provide potential research *** review may be an inform ative reference for those newly accessing the GPS-based purpose imputation field and/or intending to develop solutions to this problem.

关键词： transportation engineering Travel survey GPS Purpose imputation Human geography Activity inference

Laterites-bearing REEs,Wadi Natash,Southeastern Desert,Egypt

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Journal of Rare Earths 2010年第3期28卷 471-476页

作者： Mohamed El-Ahmady Ibrahim Nuclear Materials authority P.O.Box530EL MaadiCairoEgypt

The present paper recorded the occurrence of laterites-bearing REEs in Natash *** laterite deposits occur as horizons(5-15 m in thickness) at the boundary between the Cretaceous sandstones,and Natash *** was recorded in more than twenty six occurrence distributed over an area of about 500 km2 along and around Wadi *** ranges in color from light-grey,dark-grey to *** distribution of laterite deposits is structural *** results of laterites proved the...

关键词： Natash flows laterites clay minerals REEs

Predicting shear strength of slender beams without reinforcement using hybrid gradient boosting trees and optimization algorithms

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Frontiers of Structural and Civil Engineering 2022年第10期16卷 1267-1286页

作者： Thuy-Anh NGUYEN Hai-Bang LY Van Quan TRAN Department of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam

Shear failure of slender reinforced concrete beams without stirrups has surely been a complicated occurrence that has proven challenging to adequately *** primary purpose of this work is to develop machine learning models capable of reliably predicting the shear strength of non-shear-reinforced slender beams(SB).A database encompassing 1118 experimental findings from the relevant literature was compiled,containing eight distinct *** Boosting(GB)technique was developed and evaluated in combination with three different optimization algorithms,namely Particle Swarm Optimization(PSO),Random Annealing Optimization(RA),and Simulated Annealing Optimization(SA).The findings suggested that GB-SA could deliver strong prediction results and effectively generalizes the connection between the input and output *** values and two-dimensional PDP analysis were then carried *** may use the findings in this work to define beam’s geometrical components and material used to achieve the desired shear strength of SB without reinforcement.

关键词： slender beam shear strength gradient boosting optimization algorithms

Effects of long-term organic fertilization on soil microbiologic characteristics,yield and sustainable production of winter wheat

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Journal of Integrative Agriculture 2018年第1期17卷 210-219页

作者： LI Chun-xi MA Shou-chen SHAO Yun MA Shou-tian ZHANG Ling-ling College of Life Science Henan Normal University Field Scientific Observation and Research Base of land Use Ministry of Land and Resources/Henan Polytechnic University

We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K （NPK） fertilizer was taken as the control （CK） and three organic fertilization treatments were used： NPK fertilizer＋pig manure （T1）, NPK fertilizer＋straw return （T2）, NPK fertilizer＋pig manure＋straw return （T3）. The results showed that all three organic fertilization treatments （T1, T2 and T3） significantly increased both soil total N （STN） and soil organic carbon （SOC） from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease （sucrase） and the soil respiration rate （SRS） for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon （SMBC） and microbial biomass nitrogen （SMBN）, the SMBC/SMBN ratio and the microbial quotient （qMB）. The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation （CV） of wheat yield and increased the sustainable yield index （SYI）. Wheat grain yield was significantly positively correlated with each of the soil microbial properties （P〈0.01）. These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.

关键词： winter wheat long-term organic fertilization soil microbial features yield stability yield sustainability

Assessment of different machine learning techniques in predicting the compressive strength of self-compacting concrete

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Frontiers of Structural and Civil Engineering 2022年第7期16卷 928-945页

作者： Van Quan TRAN Hai-Van Thi MAI Thuy-Anh NGUYEN Hai-Bang LY Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam

The compressive strength of self-compacting concrete(SCC)needs to be determined during the construction design *** paper shows that the compressive strength of SCC(CS of SCC)can be successfully predicted from mix design and curing age by a machine learning(ML)technique named the Extreme Gradient Boosting(XGB)algorithm,including non-hybrid and hybrid *** ML techniques,such as Linear regression(LR),K-Nearest Neighbors(KNN),Support Vector Machine(SVM),Decision Trees(DTR),Random Forest(RF),Gradient Boosting(GB),and Artificial Neural Network using two training algorithms LBFGS and SGD(denoted as ANN_LBFGS and ANN_SGD),are also compared with the XGB ***,the hybrid models of eight ML techniques and Particle Swarm Optimization(PSO)are constructed to highlight the reliability and accuracy of SCC compressive strength prediction by the XGB_PSO hybrid *** highest number of SCC samples available in the literature is collected for building the ML *** with previously published works’performance,the proposed XGB method,both hybrid and non-hybrid models,is the most reliable and robust of the examined techniques,and is more accurate than existing ML methods(R2=0.9644,RMSE=4.7801,and MAE=3.4832).Therefore,the XGB model can be used as a practical tool for engineers in predicting the CS of SCC.

关键词： compressive strength self-compacting concrete machine learning techniques particle swarm optimization extreme gradient boosting

A study on the rare earth ore containing scandium by high gradient magnetic separation

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Journal of Rare Earths 2010年第4期28卷 622-626页

作者：高利坤陈云 Faculty of land Resources Engineering Kunming University of Science and Technology

Scandium (Sc) concentration from the rare earth ore by high gradient magnetic separation (HGMS) was determined on the basis of Sc content, geophysical parameter determination and the magnetic analyses of the ore. Based on the condition experiments, expanding experiments were carried out. The results showed that the ore had a Sc grade of 48.90 g/t, and after removing iron by low-intensity magnetic separation, a Sc concentrate of 314.89 g/t grade and with 77.53% recovery was obtained by one-stage roughing-one...

关键词： scandium high gradient magnetic separation rare earths

Effect of Soil C,N and P Stoichiometry on Soil Organic C Fractions After Afforestation

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Pedosphere 2017年第4期27卷 705-713页

作者： ZHAO Fazhu ZHANG Lu SUN Jiao REN Chengjie HAN Xinhui YANG Gaihe PANG Guowei BAI Hongying WANG Jun College of Urban and Environmental Sciences Northwest University Shaanxi land Construction Group Shaanxi LCG Land Project Technology InstituteKey Laboratory of Degraded and Unused Land Consolidation Engineeringthe Ministry of Land and Resources of China Institute of Agricultural Resources and Environment Ningxia Academy of Agriculture and Forestry Sciences College of Agronomy Northwest A&F University

Afforestation is recognized as an important driving force for soil organic C(SOC) dynamics and soil element *** evaluate the relationships between soil C:N:P stoichiometry and SOC fractions,soil C:N:P stoichiometry distributions at 0–200 cm soil depths were analyzed and the contents of SOC fractions were evaluated in 9 typical land-use systems on the Loess Plateau of *** contents of light fraction organic C,particulate organic C(>53,53–2 000,and>2 000 μm),labile organic C,microbial biomass C,and dissolved organic C decreased with increasing soil depth and were higher in afforested soil than in slope cropland *** with the slope cropland,different vegetation types influenced soil C:N,C:P,and N:P ratios,especially when C:P and N:P ratios were significantly higher(P<0.05).Moreover,SOC fractions at the 0–10 and 10–40 cm depths were particularly affected by soil C:P ratio,whereas those at the 40–100 and 100–200 cm soil depths were significantly affected(P<0.05) by soil N:P *** results indicate that changes in SOC fractions are largely driven by soil C:P and N:P ratios at different soil depths after afforestation.

关键词： dissolved organic C, labile organic C, light fraction organic C, microbial biomass C, particulate organic C

Traffic flow of connected and automated vehicles at lane drop on two-lane highway: An optimization-based control algorithm versus a heuristic rules-based algorithm

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Chinese Physics B 2023年第1期32卷 380-391页

作者：刘华清姜锐田钧方朱凯旋 Key Laboratory of transport Industry of Big Data Application Technologies for Comprehensive transport Ministry of TransportBeijing Jiaotong UniversityBeijing 100044China College of Management and Economics Tianjin UniversityTianjin 300072China Suzhou Institute of Technology Jiangsu University of Science and TechnologyZhangjiagang 215600China

This paper investigates traffic flow of connected and automated vehicles at lane drop on two-lane highway. We evaluate and compare performance of an optimization-based control algorithm(OCA) with that of a heuristic rules-based algorithm(HRA). In the OCA, the average speed of each vehicle is maximized. In the HRA, virtual vehicle and restriction of the command acceleration caused by the virtual vehicle are introduced. It is found that(i) capacity under the HRA(denoted as C_(H)) is smaller than capacity under the OCA;(ii) the travel delay is always smaller under the OCA, but driving is always much more comfortable under the HRA;(iii) when the inflow rate is smaller than C_(H), the HRA outperforms the OCA with respect to the fuel consumption and the monetary cost;(iv) when the inflow rate is larger than C_(H), the HRA initially performs better with respect to the fuel consumption and the monetary cost, but the OCA would become better after certain time. The spatiotemporal pattern and speed profile of traffic flow are presented, which explains the reason underlying the different performance. The study is expected to help for better understanding of the two different types of algorithm.

关键词： traffic flow connected and automated vehicles(CAVs) lane drop optimization-based control algorithm Heuristic rules-based algorithm