检索结果-南通市图书馆

Journal of Transportation Technologies 2024年第2期14卷 179-194页

作者： Shauna Hallmark Guillermo Basulto-Elias Nicole Oneyear Omar Smadi institute for Transportation 2711 S. Loop Drive Suite 4700 Ames Iowa Iowa Division Federal Highway Administration Ames Iowa

The SHRP2 Naturalistic Driving Study was used to evaluate the impact of various work zone and driver characteristics on back of queue safety critical events (crash, near-crash, or conflicts) The model included 43 SCE and 209 “normal” events which were used as controls. The traces included representing 209 unique drivers. A Mixed-Effects Logistic Regression model was developed with probability of a SCE as the response variable and driver and work zone characteristics as predictor variables. The final model indicated glances over 1 second away from the driving task and following closely increased risk of an SCE by 3.8 times and 2.9 times, respectively. Average speed was negatively correlated to crash risk. This is counterintuitive since in most cases, it is expected that higher speeds are related to back of queue crashes. However, most queues form under congested conditions. As a result, vehicles encountering a back of queue would be more likely to be traveling at lower speeds.

关键词： Safety Critical Events Speed Following Closely Glance Behavior

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan(Siberia)

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 Forestry research 2024年第3期35卷 13-27页

作者： Elena A.Babushkina Dmitry R.Dergunov Mikhail S.Zharkov Liliana V.Belokopytova Dina F.Zhirnova Bao Yang Jingjing Liu Xiaomei Peng Eugene A.Vaganov Khakass Technical institute Siberian Federal UniversityAbakan 655017Russia institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660036Russia Mathematical Methods and IT Department Siberian Federal UniversityKrasnoyarsk 660036Russia Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000People's Republic of China School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210093People's Republic of China Department of Dendroecology V.N.Sukachev Institute of ForestSiberian Branch of the Russian Academy of ScienceKrasnoyarsk 660036Russia

Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronologies of tracheid measurements, indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width). To fill gaps in understanding the impact of climate on conifer xylem structure, Scots pine(Pinus sylvestris L.)trees > 200 years old were selected within the forest-steppe zone in southern Siberia. Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes. Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree *** a low level of climatogenic stress, components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation. Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat), maximum cell size formed late June. A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July. Secondary wall deposition lasted until mid-September, suppressed by end of season temperatures. Generally, anatomical climatic responses were modulated by a less dry May and September compared with summer months.

关键词： Quantitative wood anatomy Cell radial size Cell wall thickness Pinus sylvestris Climatic response

Portable Structure Surface Crack Detection System Based on Android Platform

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2024年第2期29卷 154-164页

作者： WANG Huifeng PENG Haonan TANG Yu GUAN Yueyuan LIANG Yaru WANG Lisha ZHAO Yu WANG Xiaoyan GAO Rong HUANG He School of Electronics and Control Engineering Chang'an UniversityXi'an 710000ShaanxiChina research institute of highway Ministry of Transport Beijing 100000China State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610000SichuanChina highway School Chang'an UniversityXi'an 710000ShaanxiChina

Cracks,potholes,and other defects often occur on infrastructure such as bridges,among which cracks are one of the most frequent *** have diverse shapes and are difficult to *** manual inspection methods are inefficient and have low accuracy,while automated inspection machines are bulky and inconvenient to carry and *** on the shortcomings of existing detection technologies,this paper proposes a portable structural surface crack detection system based on the Android platform using a portable hand-held image acquisition *** system captures cracks on the structure's surface and obtains high-definition crack ***,these images are transmitted to portable smartphone terminals through ***,the image is pre-processed using weighted averaging,grayscale linear transformation,and adaptive median ***,the improved Canny edge detection algorithm is applied to identify crack information,and the edge segmentation algorithm is used to determine the crack ***,based on camera calibration,the pixels are converted into the length data required for actual *** results show that the system is easy to operate,and it not only has crack storage and tracking functions,but also can effectively measure the crack width on the surface of *** measurement accuracy of this system reaches the sub-pixel level,and in actual testing,compared with the crack width gauge,the maximum relative error does notexceed6.25%.

关键词： structural crack portable image processing detection accuracy crack parameter

Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry research 2024年第2期35卷 70-80页

作者： Aleksey S.Ilintsev Elena N.Nakvasina Alexander P.Bogdanov Northern research institute of Forestry 13 Nikitova Str.Arkhangelsk 163062Russian Federation Department of Silviculture and Forest Management Northern(Arctic)Federal University Named After M.V.LomonosovSevernoy Dviny Emb.17Arkhangelsk 163002Russian Federation

This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of *** study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess *** the rooting layer,240 soil samples were taken to determine physical *** study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina ***,reduced soil moisture was noted,particularly in mounds,resulting in increased *** Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the *** treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration *** the Myrtillus and Polytrichum sites,patch scarification had no effects on physical *** Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to *** Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil *** conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.

关键词： Boreal forests Mechanical site preparation Patch scarification Mounding Soil properties Containerised seedlings Bareroot seedlings

Parasites of the liver:A global problem?

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第30期30卷 3554-3559页

作者： Vladislav V Tsukanov Alexander V Vasyutin Julia L Tonkikh Clinical Department of the Digestive System Pathology of Adults and Children Federal Research Center“Krasnoyarsk Science Center”of the Siberian Branch of the Russian Academy of SciencesScientific Research Institute of Medical Problems of the NorthKrasnoyarsk 660022Russia

Parasitic liver diseases can be caused by trematodes,cestodes,nematodes,and *** pathology is significant because millions of people in different parts of the world have liver parasites,which can manifest themselves in the development of inflammation,liver cysts,cholecystitis,cholelithiasis,pancreatitis and liver cirrhosis that are often threatening their *** International Agency for research on Cancer considers three species of trematodes,Schistosoma haematobium,Opisthorchis viverrini and Clonorchis sinensis,to be *** modern examination methods,in some cases including extensive screening of large populations,are required for diagnosing liver *** of parasitic liver diseases is differentiated and can involve a combination of surgical and therapeutic *** is no doubt that the clinical and epidemiological scale allows one to regard parasitic liver diseases as a global healthcare problem.

关键词： Liver Parasites Epidemiology Diagnosis Clinics Treatment Echinococcosis Opisthorchiasis Fascioliasis Schistosomiasis

Energy Planning of Beijing Towards Low-carbon,Clean and Efficient Development in 2035

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 913-928页

作者： Chengzhou Li Ningling Wang Xiaohu Shen Yumeng Zhang Zhiping Yang Xiaofeng Tong François Maréchal Ligang Wang Yongping Yang institute of Energy Power Innovation North China Electric Power UniversityBeijing 102206China School of Energy Power and Mechanical Engineering and National Research Center for Thermal Power Engineering and TechnologyNorth China Electric Power UniversityBeijing 102206China Industrial Process and Energy Systems Engineering Swiss Federal Institute of Technology in LausanneSionSwitzerland

Energy transition towards clean,efficient energy supply has been a common sense of the government and public in ***,lacking reasonable planning will lead to undisciplined development,resource waste,and excessive *** this context,this paper investigates potential pathways of Beijing energy transition towards a high-level low-carbon,clean and efficient energy system in 2035 with an extended energysocpe ***,based on available data,future energy demands are predicted by a newly proposed hybrid forecasting method,which combines the traditional regression model,grey model,and support vector machine model with an entropy-based weighted ***,the superstructure-based optimization model is employed to investigate the system configuration and operation strategy of the future Beijing energy ***,the uncertainty impact of electricity price,natural gas price,hydrogen price,and the capital expenditures of electrolyzer and steam methane reforming for hydrogen applications are *** forecasting results show that all walks of life will witness a continuously increasing energy demand in multiple sectors of Beijing towards *** planning results suggest that the imported electricity and natural gas will dominate the energy supply of Beijing in 2035 with a contribution of 86%of the energy resources consumption of 384 ***,the energy system presents a high end-use electrification level of 65%and high penetration of efficient technologies,which supply 119 TWh via combined heat and power,26 TWh via heat pump and 95 TWh via district heating *** energy use of various sectors of energy resources,technologies and end-use are closely *** will have an increased penetration in the private mobility sector,but the locally generated hydrogen is mainly from steam methane reforming technology.

关键词： Energy transition energy planning carbonneutral demand forecasting energyscope

Structural changes in the obese brain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration research 2024年第12期19卷 2561-2562页

作者： Anna R.R.Da Conceicao Marcelo N.N.Vieira Fernanda G.De Felice D’Or institute for research and Education Rio de JaneiroBrazil institute of Medical Biochemistry Leopoldo De Meis Federal University of Rio de JaneiroRio de JaneiroBrazil Centre for Neuroscience Studies Department of Biomedical and Molecular Sciences&Department of PsychiatryQueen’s UniversityKingstonONCanada

Obesity represents a major global health concern,with widespread growing prevalence and severe consequences for the quality of life and life expectancy of affected individuals and for the economic burden of healthcare systems(Prospective Studies Collaboration,2009).Obesity is a well-established risk factor for a variety of conditions including metabolic,vascula r,and heart diseases,and seve ral types of cancer(Prospective Studies Collaboration,2009).

关键词： diseases consequences prevalence

Structural correlation and chemistry of molten NaF-ScF_(3) with dissolved metal aluminium:TG/DTA,XRD,NMR and molecular dynamics simulations

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3356-3369页

作者： Aydar Rakhmatullin Frantisek simko Didier Zanghi Zuzana Netriová Ilya BPolovov Ayrat Dimiev Konstantin V.Maksimtsev Catherine Bessada Michal Korenko Conditions Extrêmes et Materiaux:Haute Température et Irradiation CEMHTIUPR 3079-CNRS Univ Orleans45071 OrleansFrance Department of Molten Systems Institute of Inorganic ChemistrySlovak Academy of Sciencess84536BratislavaSlovakia Centre of Excellence for Advanced Materials Application-CEMEA Slovak Academy of Sciences84511Bratislava.Slovakia Department of Rare Metals and Nanomaterials Institute of Physics and TechnologyUral Federal UniversityUral Federal University620002 EkaterinburgRussia Alexander Butlerov institute of Chemistry Kazan Federal University420008KazanRussia

For the first time,the mechanism of metal aluminum dissolution in NaF-ScF_(3) eutectic melts and the chemical interaction between the constituents of this mixture have been thoroughly studied by a combination of differential thermal analysis(DTA),high temperature and solid-state nuclear magnetic resonance(NMR),and X-ray diffraction(XRD) coupled with the molecular dynamic *** formation of an insoluble Al_(3)Sc alloy in molten(NaF-ScF_(3))_(eut)system was proven,and the chemical mechanism of this aluminothermic Al_(3)Sc alloy production was *** ex situ examinations bring to light the formation of NaScF_4 and solid solution of Na_(3)(Al,Sc)F_(6) in cooled *** molecular dynamics calculations of the bath allow us to construct the structural model and to predict viscosity,density and electrical conductivity of the reagent melt to help to optimize the conditions of the alloy synthesis.

关键词： Scandium Alloy Molten salts NMR Molecular dynamics

Three dimensional discrete element modelling of the conventional compression behavior of gas hydrate bearing coal

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2024年第1期11卷 61-77页

作者： Xia Gao Nannan Wang Baoyong Zhang Qiqi Lin Qiang Wu Wei Meng Xia Liu Department of Architecture and Civil Engineering Heilongjiang University of Science and TechnologyHarbin150022China School of Qilu Transportation Shandong UniversityJinan250061China Department of Safety Engineering Heilongjiang University of Science and TechnologyHarbin150022China Jining Hongxiang highway Survey Design and research institute Co.Ltd Jining272000China

To analyze the relationship between macro and meso parameters of the gas hydrate bearing coal(GHBC)and to calibrate the meso-parameters,the numerical tests were conducted to simulate the laboratory triaxial compression tests by PFC3D,with the parallel bond model employed as the particle contact constitutive ***,twenty simulation tests were conducted to quantify the relationship between the macro–meso ***,nine orthogonal simulation tests were performed using four meso-mechanical parameters in a three-level to evaluate the sensitivity of the meso-mechanical ***,the calibration method of the meso-parameters were then ***,the contact force chain,the contact force and the contact number were examined to investigate the saturation effect on the meso-mechanical behavior of *** results show that:(1)The elastic modulus linearly increases with the bonding stiffness ratio and the friction coefficient while exponentially increasing with the normal bonding strength and the bonding radius *** failure strength increases exponentially with the increase of the friction coefficient,the normal bonding strength and the bonding radius coefficient,and remains constant with the increase of bond stiffness ratio;(2)The friction coefficient and the bond radius coefficient are most sensitive to the elastic modulus and the failure strength;(3)The number of the force chains,the contact force,and the bond strength between particles will increase with the increase of the hydrate saturation,which leads to the larger failure strength.

关键词： Gas hydrate bearing coal Discrete element method Triaxial compression test Macro-meso mechanical propertie

Deformation and stability of the seawall,considering the strength uncertainty of cement mixing piles

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 Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 483-501页

作者： Yuansheng YU Lingling LI Xiangmiao KONG Chengyuan LI Zhen GUO Key Laboratory of Offshore Geotechnics and Material of Zhejiang Province College of Civil Engineering and ArchitectureZhejiang UniversityHangzhou310058China Hainan institute Zhejiang UniversitySanya572000China Ninghai highway and Transportation Management Center Ningbo315600China Ninghai Traffic Engineering Construction Management institute Ningbo315600China

The cement mixing (CM) pile is a common method of improving soft offshore ground. The strength growth of CM piles under complex conditions is affected by many factors, especially the cement and moisture contents, and shows significant uncertainty. To investigate the stochasticity of the early strength of CM piles and its impact on the displacement and stability of a seawall, a series of laboratory tests and numerical analyses were carried out in this study. Vane shear tests were conducted on the cement-solidified soil to determine the relationships between the undrained shear strength s_(u) of the cement soil curing in the seawater and the cement content a_(c), as well as the in situ soil moisture content w. It can be inferred that the 24 h undrained shear strength follows a normal distribution. A numerical model considering the random CM pile strength was established to investigate the deformation of the seawall. Due to the uncertainty of CM pile strength, the displacement of the seawall demonstrates a certain discreteness. The decrease of the mean undrained shear strength of CM piles causes a corresponding increase in the average displacement of the seawall. When the mean strength of CM piles is lower than a certain threshold, there is a risk of instability. Furthermore, the heterogeneity of the strength within an individual CM pile also has an impact on seawall displacement. Attention should be paid to the uncertainty of CM pile strength to control displacement and stability.

关键词： Construction uncertainty Cement mixing(CM)pile Strength of cement soil Seawall stability Random finite element method(RFEM) Monte Carlo simulation(MCS)