检索结果-南通市图书馆

Size distributions of aerosol and water-soluble ions in Nanjing during a crop residual burning event

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 Environmental Sciences 2012年第8期24卷 1457-1465页

作者： honglei wang Bin Zhu Lijuan Shen Hanqing Kang Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and TechnologyNanjing 210044China.

To investigate the impact on urban air pollution by crop residual burning outside Nanjing, aerosol concentration, pollution gas concentration, mass concentration, and water-soluble ion size distribution were observed during one event of November 4-9, 2010. Results show that the size distribution of aerosol concentration is bimodal on pollution days and normal days, with peak values at 60- 70 and 200-300 nm, respectively. Aerosol concentration is 104 ***-1 on pollution days. The peak value of spectrum distribution of aerosol concentration on pollution days is 1.5-3.3 times higher than that on a normal day. Crop residual burning has a great impact on the concentration of fine particles. Diurnal variation of aerosol concentration is trimodal on pollution days and normal days, with peak values at 03：00, 09：00 and 19：00 local standard time. The first peak is impacted by meteorological elements, while the second and third peaks are due to human activities, such as rush hour traffic. Crop residual burning has the greatest impact on SO2 concentration, followed by NO2, 03 is hardly affected. The impact of crop residual burning on fine particles （〈 2.1 μm） is larger than on coarse particles （〉 2.1 μm）, thus ion concentration in fine particles is higher than that in coarse particles. Crop residual burning leads to similar increase in all ion components, thus it has a small impact on the water-soluble ions order. Crop residual burning has a strong impact on the size distribution of K^＋, Cl^-, Na^＋, and F- and has a weak impact on the size distributions of NH4^＋, Ca^2＋, NO3^- and SO4^2-.

关键词： crop residual burning atmospheric aerosol number concentration mass concentration water-soluble ions size distribution

6G:Ubiquitously Extending to the Vast Underwater World of the Oceans

在线全文

学校读者我要写书评

暂无评论

Engineering 2022年第1期8卷 12-17页

作者： Yuanliang Ma Qunfei Zhang honglei wang School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China

*** There is a significant gap between atmospheric space and undersea space for wireless radio *** interface between air and seawater is a barrier to prevent radio wave transmission across the *** is because seawater is an electrically conducting medium,and radio waves suffer significant absorptive attenuation *** a result,there is no internet,reliable mobile communication,high-quality video,and long-distance duplex wireless communication in the underwater world of *** is pitiful since the oceans share 71%of the surface of our planet and are of great importance to our economy,ecology,and living environment.

关键词： communication wireless planet

Mixing state of individual carbonaceous particles during a severe haze episode in January 2013,Nanjing,China

在线全文

学校读者我要写书评

暂无评论

Particuology 2015年第3期13卷 16-23页

作者： honglei wang Bin Zhu Zefeng Zhang Junlin An Lijuan Shen Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science and Technology Jiaxing Environmental Monitoring Station

Chemical composition, hourly counts, and sizes of atmospheric carbonaceous particles were measured to investigate their mixing state on clear and hazy days. 823,122 carbonaceous particles with sizes 0.2-2.0μm was analyzed using a single-particle aerosol mass spectrometer from 1st to 17th January 2013. Particle types included biomass/biofuel burning particles （biomass）, element carbon （EC-dominant） particles that were also mixed with biomass/biofuel burning species （EC-biomass） or secondary species （EC-secondary）, organic carbon （OC）, internally mixed OC and EC （OCEC）, ammonium-containing （ammo- nium） and sodium-containing （sodium） particles. On clear days the top ranked carbonaceous particle types were biomass （48.2%）, EC-biomass （15.7%）, OCEC （11.1%）, and sodium （9.6%）, while on hazy days they were biomass （37.3%）, EC-biomass （17,6%）, EC-secondary （16.6%）, and sodium （12.7%）. The fractions of EC-secondary, ammonium （10%）, and sodium particle types were elevated on hazy days. Numbers of EC-secondary particles were more than four times those on clear days （4.1%）. Thus, carbonaceous particles mixed with ammonium, nitrate and sulfate during aging and transport, enhancing their light extinction effects and hygroscopic growth under high relative humidity on hazy days, further reducing visibility. Our real-time single-particle data showed that changes to mixing state had a significant impact on light extinction during haze events in Nanjing.

关键词： HazeSingle particleMixing stateSPAMSCarbonaceous particleSecondary aerosols

Highly conductive wear resistant Cu/Ti3SiC2(TiC/SiC) co-continuous composites via vacuum infiltration process

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2020年第1期9卷 83-93页

作者： Dexuan YANG Yu ZHOU Xingheng YAN honglei wang Xingui ZHOU Science and Technology on Advanced Ceramic Fibers and Composites Laboratory National University of Defense TechnologyChangsha 410073China Department of Mechanical Materials and Aerospace EngineeringIllinois Institute of TechnologyChicago 60616USA

The MAX phase Ti3SiC2 has broad application prospects in the field of rail transit,nuclear protective materials and electrode materials due to its excellent electrical conductivity,selflubricating properties and wear ***–Ti3SiC2 co-continuous composites have superior performance due to the continuous distribution of 3 D network *** this paper,the Cu/Ti3SiC2(Ti C/Si C)co-continuous composites are formed via vacuum infiltration process from Cu and Ti3SiC2 porous *** co-continuous composites have significantly improved the flexural strength and conductivity of Ti3SiC2 due to the addition of Cu,with the conductivity up to 5.73×10^5 S/m,twice as high as the Ti3SiC2 porous ceramics and five times higher than *** reaction between ingredients leads to an increase in the friction coefficient,while the hard reaction products(Ti Cx,Si C)lower the overall wear rate(1×10^–3 mm^3/(N·m)).Excellent electrical conductivity and wear resistance make co-continuous composites more advantageous in areas such as rail transit.

关键词： Ti3SiC2 metal–ceramic co-continuous composites vacuum infiltration high conductive

Synthesis and Characterization of Novel UV-curable Fluorinated Polyurethane-acrylate Copolymer

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2016年第2期32卷 311-317页

作者： wang honglei LIU Weiqu TAN Jianquan XIAHOU Guolun Guangzhou Institute of Chemistry Chinese Academy of Sciences Guangzhou 510650 P. R. China Key Laboratory of Cellulose and Lignocellulosics Chemistry Chinese Academy of Sciences Guangzhou 510650 P R. China University of Chinese Academy of Sciences Beijing 100049 P. R. China

A series of UV-curable fluorinated polyurethane-acrylate（PUA） has been developed by incorporating octafluoropentyl alcohol into the segment of UV-curable polyurethane-acrylate to improve the thermal property and surface property of the copolymer material. The structures of the synthesized polymers were characterized by Fourier transform infrared（FTIR） spectrometry. In order to find out the effect of incorporated fluorine on the UV-cured films, the properties of the UV-cured films were tested through contact angle, water absorption, and thermogravimetric analysis （TGA）. The fractured-surface morphologies of the UV-cured coatings were investigated by scanning electron microscopy（SEM）. With increasing the content of fluorine segments, the contact angle of the UV-cured films increased and the water absorption decreased, suggesting the fluorine segments migrated and formed a fluorine-covered surface to avoid water penetration. The observation of the fractured-surface morphology through SEM test showed that the fluori- nated UV-cured films gained rough fractured-surface compared with the pure UV-cured polyacrylate film, demonstrating the migrating of the fluorine segments. The TGA curves show that the fluorinated UV-cured films gained higher thermal degradation temperature than the virgin UV-cured polyacrylate film. And as increasing the fluorine content, the thermal degradation temperature increased. These phenomena could be reasonably explained by the enrichment of fluorinecontained segment on the surface of the film and the high thermal property due to fluorine atom.

关键词： Fluorinated polyurethane Functional acrylate oligomer UV-cured film Hydrophobic surface

Experimental and numerical interpretation on composite foundation consisting of soil-cement column within warm and ice-rich frozen soil

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1期21卷 313-321页

作者： wang honglei ZHANG Jianming WEI Shoucai SUN Zhizhong ZHANG Hu School of Civil Engineering Hebei University of EngineeringHandan 056038China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Second Geological Brigade Bureau of Geology and Mineral Resources Exploration and DevelopmentLhasa 850000China Da Xing’anling Observation and Research Station of Frozen Ground Engineering and Environment Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesJiagedaqi 165100China School of Civil Engineering Northeast Forestry UniversityHarbin 150040China

Affected by climate warming and anthropogenic disturbances, the thermo-mechanical stability of warm and ice-rich frozen ground along the Qinghai-Tibet engineering corridor(QTEC) is continuously decreased, which may delay the construction of major projects in the future. In this study, based on chemical stabilization of warm and icerich frozen ground, the soil-cement column(SCC) for ground improvement was recommended to reinforce the foundations in warm and ice-rich permafrost regions. To explore the validity of countermeasures mentioned above, both the original foundation and the composite foundation consisting of SCC with soil temperature of -1.0℃ were prepared in the laboratory, and then the plate loading tests were carried out. The laboratory investigations indicated that the bearing capacity of composite foundation consisting of SCC was higher than that of original foundation, and the total deformation of original foundation was greater than that of composite foundation, meaning that overall stability of foundation with warm and ice-rich frozen soil can be improved by SCC installation. Meanwhile, a numerical model considering the interface interaction between frozen soil and SCC was established for interpretating the bearing mechanism of composite foundation. The numerical investigations revealed that the SCC within composite foundation was responsible for the more applied load, and the applied load can be delivered to deeper zone in depth due to the SCC installation, which was favorable for improving the bearing characteristic of composite foundation. The investigations provide the valuable guideline for the choice of engineering supporting techniques to major projects within the QTEC.

关键词： Chemical stabilization Ground improvement Composite foundation Frozen soil engineering Qinghai-Tibet engineering corridor

Mechanical behaviors of warm and ice-rich frozen soil stabilized with sulphoaluminate cement

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 335-345页

作者： wang honglei ZHANG Hu ZHANG Jianming ZHANG Qi YIN Zhenhua State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China School of Civil Engineering and Transportation Northeast Forestry UniversityHarbin 150040China National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment CCCC First Highway Consultants Co.LtdXi'an 710065China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China

The warm and ice-rich frozen soil is characterized by high unfrozen water content, low shear strength and large compressibility, which is unreliable to meet the stability requirements of engineering infrastructures and foundations in permafrost regions. In this study, a novel approach for stabilizing the warm and ice-rich frozen soil with sulphoaluminate cement was proposed based on chemical stabilization. The mechanical behaviors of the stabilized soil, such as strength and stress-strain relationship, were investigated through a series of triaxial compression tests conducted at -1.0℃, and the mechanism of strength variations of the stabilized soil was also explained based on scanning electron microscope test. The investigations indicated that the strength of stabilized soil to resist failure has been improved, and the linear Mohr-Coulomb criteria can accurately reflect the shear strength of stabilized soil under various applied confining pressure. The increase in both curing age and cement mixing ratio were favorable to the growth of cohesion and internal friction angle. More importantly, the strength improvement mechanism of the stabilized soil is attributed to the formation of structural skeleton and the generation of cementitious hydration products within itself. Therefore, the investigations conducted in this study provide valuable references for chemical stabilization of warm and ice-rich frozen ground, thereby providing a basis for in-situ ground improvement for reinforcing warm and ice-rich permafrost foundations by soil-cement column installation.

关键词： Permafrost regions Frozen soil Mechanical behavior Chemical stabilization Ground improvement Ground modification

Precise quantification of the antibacterial activity of chitosan by NB medium neutralizer

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第11期70卷 224-232页

作者： Mengyang wang Shichao Bi Jianhui Pang Zhongzheng Zhou Di Qin honglei wang Xiaojie Cheng Xiguang Chen College of Marine Life Science Ocean University of ChinaQingdao 266003China Qingdao National Laboratory for Marine Science and Technology Qingdao 266000China The Key Laboratory of Plant Development and Environmental Adaptation Biology Ministry of EducationSchool of Life ScienceShandong UniversityQingdao 266237China

In the present research,nutrient broth(NB)medium was identified to be able to neutralize the antibacterial activity of chitosan and its ***,an improved test method independent of NB medium was proposed to precisely quantify the antibacterial effectiveness and efficiency of *** minimum bactericidal concentration(MBC)of chitosan was 60μg m L^(-1) against *** and ***,and 0.01%(w/v)chitosan could kill 100%of bacteria within 3 *** another point of view,the neutralizing efficiency of NB could be tripled by adding 25 g L^(-1) of sodium *** the neutralizing mechanism of NB medium was ascribed to flocculation between chitosan and *** extra sodium chloride could significantly reduce the size of floccules,and smaller floccules would lose the ability of binding with bacteria directly,showing higher neutralizing rate on the macro scale.

关键词： Chitosan Antibacterial activity Neutralizer Flocculation

Rheological mechanical properties and its constitutive relation of soft rock considering influence of clay mineral composition and content

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2023年第4期10卷 62-76页

作者： Xuebin Li Xuesheng Liu Yunliang Tan Ai Chen honglei wang Xin wang Shenglong Yang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China Ningxia Coal Industry Co. Ltd.of China Energy GroupYinchuan 750000China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China

Rheological mechanical properties of the soft rock are afected signifcantly by its main physical characteristics-clay *** this study,taking the mudstone on the roof and foor in four typical mining regions as the research object,frstly,the clay mineral characteristic was analyzed by the X-ray difraction ***,rheological mechanical properties of mudstone samples under diferent confning pressures are studied through triaxial compression and creep *** results show that the clay mineral content of mudstone in diferent regions is diferent,which leads to signifcant diferences in its rheological properties,and these diferences have a good correlation with the content of montmorillonite and illite-montmorillonite mixed *** the montmorillonite content as an example,compared with the sample with 3.56%under the lower stress level,the initial creep deformation of the sample with 11.19%increased by 3.25 times,the viscosity coefcient and longterm strength decreased by 80.59%and 53.94%,***,based on the test results,the damage variation is constructed considering the montmorillonite content and stress level,and the M–S creep damage constitutive model of soft rock is ***,the test results can be ftted with determination coefcients ranging from 0.9020 to 0.9741,which proves that the constitutive relation can refect the infuence of the clay mineral content in the samples *** study has an important reference for revealing the long-term stability control mechanism of soft rock roadway rich in clay minerals.

关键词： Clay mineral Physical characteristic Creep Damage Constitutive model