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Change in Grain-Size Composition of Lignite under Cyclic Freezing-Thawing and Wetting-Drying
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作者 Natalia S. Batugina Vladislav I. Fedorov 《Natural Resources》 2024年第1期17-27,共11页
The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to... The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying. 展开更多
关键词 LIGNITE Freezing-Thawing Cycle Wetting-Drying Cycle Grain size composition Dust Coal Storage Loss Quality
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Grain size composition and transport of sedimentary organic carbon in the Changjiang River(Yangtze River) Estuary and Hangzhou Bay and their adjacent waters 被引量:4
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作者 ZHANG Weiyan JIN Haiyan +5 位作者 YAO Xuying JI Zhongqiang ZHANG Xiaoyu YU Xiaoguo ZHANG Fuyuan GAO Aigen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第10期46-56,共11页
Surface sediments from the Changjiang River (Yangtze River) Estuary, Hangzhou Bay, and their adjacent waters were analyzed for their grain size distribution, organic carbon (OC) concentration, and stable carbon is... Surface sediments from the Changjiang River (Yangtze River) Estuary, Hangzhou Bay, and their adjacent waters were analyzed for their grain size distribution, organic carbon (OC) concentration, and stable carbon isotope composition (δ13C). Based on this analysis, about 36 surface sediment samples were selected from various environments and separated into sand (〉0.250 ram, 0.125-0.250 ram, 0.063-0.125 mm) and silt (0.025-0.063 mm) fractions by wet-sieving fractionation methods, and further into silt- (0.004-0.025 mm) and clay-sized (〈0.004 mm) fractions by centrifugal fractionation. Sediments of six grain size categories were analyzed for their OC and 613C contents to explore the grain size composition and transport paths of sedimentary OC in the study area. From fine to coarse fractions, the OC content was 1.18%, 0.51%, 0.46%, 0.42%, 0.99%, and 0.48%, respectively, while the δ13C was -21.64‰, -22.03‰, -22.52‰, -22.46‰, -22.36‰, and -22.28%0, respectively. In each size category, the OC contribution was 42.96%, 26.06%, 9.82%, 5.75%, 7.09%, and 8.33%, respectively. The OC content in clay and fine silt fractions (〈0.025 ram) was about 69.02%. High OC concentrations were mainly found in offshore modern sediments in the northeast of the Changjiang River Estuary, in modern sediments in the lower estuary of the Changjiang River and Hangzhou Bay, and in Cyclonic Eddy modern sediments to the southwest of the Cheju Island. Integrating the distribution of terrestrial OC content of each grain size category with the δ13C of the bulk sediment indicated that the terrestrial organic material in the Changjiang River Estuary was transported seaward and dispersed to the Cyclonic Eddy modern sediments to the southwest of the Cheju Island via two pathways: one was a result of the Changjiang River Diluted Water (CDW) northeastward extending branch driven by the North Jiangsu Coastal Current and the Yellow Sea Coastal Current, while the other one was the result of the CDW southward extending branch driven by the Taiwan Warm Current. 展开更多
关键词 Changjiang River (Yangtze River) Estuary Hangzhou Bay grain size composition organic carbon material transport
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Material Composition and Engineering Characteristics of Red Clay in Guigang, Guangxi 被引量:4
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作者 XiaoMinggui WangJieguang ChenXuejun 《Journal of China University of Geosciences》 SCIE CSCD 2005年第1期84-88,共5页
There is fine and uniform clay with aluminous and ferrous cementation in the red clay found in Guigang, Guangxi. It has the characteristics of shrinkage outwardly, rigid upper but soft lower and well grown fissure. I... There is fine and uniform clay with aluminous and ferrous cementation in the red clay found in Guigang, Guangxi. It has the characteristics of shrinkage outwardly, rigid upper but soft lower and well grown fissure. In addition there are engineering characteristics such as high water content, low compactness and low compressibility, high strength and high contractility but slight expansibility. This paper discusses the red clay's engineering characteristics and its change regulation with depth by analyzing changes in the red clay's grain size composition, mineralogical constitution, and chemical composition. 展开更多
关键词 red clay engineering characteristics grain size composition mineralogical constitution chemical ingredients.
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Reasonable Ball Size of Ball Mill for Preparing Coal Water Fuel and Forecasting Productive Capacity 被引量:1
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作者 张荣曾 刘炯天 +1 位作者 徐志强 郑明 《Journal of China University of Mining and Technology》 2002年第2期115-119,共5页
By using the matrix theory, a 5 parameter grinding mathematical model is established. Based on the properties of feed coal and requirements for size distribution of final product, the model gives the required grinding... By using the matrix theory, a 5 parameter grinding mathematical model is established. Based on the properties of feed coal and requirements for size distribution of final product, the model gives the required grinding probability for various particles and corresponding ball size distribution. By using this model, 3 different sizes of ball mill are designed and put into commercial use for coal water fuel. The forecasted ball mill capacity, the particle sizes and particle size distribution as well as the coal water fuel quality parameters are all in line with industrial operation results, which have proved the suitability of the model. 展开更多
关键词 ball mill capacity ball size composition
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Composition-controlled synthesis of platinum and palladium nanoalloys as highly active electrocatalysts for methanol oxidation 被引量:4
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作者 Haiqiang Zhao Weihong Qi +2 位作者 Xinfeng Zhou Haofei Wu Yejun Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第2期342-349,共8页
Platinum and palladium(PtPd)alloy nanoparticles(NPs)are excellent catalysts for direct methanol fuel cells.In this study,we developed PtPd alloy NPs through the co‐reduction of K2PtCl4and Na2PdCl4in a polyol synthesi... Platinum and palladium(PtPd)alloy nanoparticles(NPs)are excellent catalysts for direct methanol fuel cells.In this study,we developed PtPd alloy NPs through the co‐reduction of K2PtCl4and Na2PdCl4in a polyol synthesis environment.During the reaction,the feed molar ratio of the two precursors was carried over to the final products,which have a narrow size distribution with a mean size of approximately4nm.The catalytic activity for methanol oxidation reactions possible depends closely on the composition of as‐prepared PtPd alloy NPs,and the NPs with a Pt atomic percentage of approximately75%result in higher activity and stability with a mass specific activity that is7times greater than that of commercial Pt/C catalysts.The results indicate that through composition control,PtPd alloy NPs can improve the effectiveness of catalytic performance. 展开更多
关键词 Platinum and palladium alloy nanoparticles composition and size control Methanol oxidation
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Comparative Study of Micro and Nano Size WO3/E44 Epoxy Composite as Gamma Radiation Shielding Using MCNP and Experiment 被引量:1
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作者 Shahryar Malekie Nahid Hajiloo 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第10期92-94,共3页
The radiation shielding characteristics of 50wt% WO3/E44 epoxy composite in various gamma energies from 80 keV to 1.33 MeV are investigated via the MCNP code. Thus two scales are considered for WOa filler particles: ... The radiation shielding characteristics of 50wt% WO3/E44 epoxy composite in various gamma energies from 80 keV to 1.33 MeV are investigated via the MCNP code. Thus two scales are considered for WOa filler particles: micro and nano with sizes of i #m and 5Onto, respectively. The simulation results show that W03 nano particles exhibit a larger increase in linear attenuation coefficient in comparison with micro size particles. Finally, validation of simulation results with the published experimental data shows a good agreement. 展开更多
关键词 Comparative Study of Micro and Nano size WO3/E44 Epoxy Composite as Gamma Radiation Shielding Using MCNP and Experiment
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Polygynous Mating System and Behavioural Reason of Black Crested Gibbon (Nomascus concolor jingdongensis) at Dazhaizi,Mt.Wuliang, Yunnan,China 被引量:12
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作者 范朋飞 蒋学龙 +1 位作者 刘长铭 罗文寿 《Zoological Research》 CAS CSCD 北大核心 2006年第2期216-220,共5页
The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females... The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2 - 5 sub-adults, juveniles and itfants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 (G3) and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3's territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3's territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi. 展开更多
关键词 Nomascus concolor jingdongensis Group size and composition Social structure Polygyny Local population Wuliang Mountain
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Significant Effects of Fishing Gear Selectivity on Fish Life History 被引量:4
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作者 LIANG Zhenlin SUN Peng +2 位作者 YAN Wei HUANG Liuyi TANG Yanli 《Journal of Ocean University of China》 SCIE CAS 2014年第3期467-471,共5页
Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller siz... Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller size-at-age, an earlier age-at-maturation and among others. Currently, the causes of these life history traits changes still require systematic analyses and empirical studies. The explanations that have been cited are merely expressed in terms of fish phenotypic adaptation. It has been claimed that the original traits of fish can be recovered once the intensity of exploitation of the fish is controlled. Sustained environmental and fishing pressure will change the life history traits of most fish species, so the fish individual's traits are still in small size-at-age and at earlier age-at-maturation in exploited fish populations. In this paper, we expressed our view of points that fishing gear has imposed selectivity on fish populations and individuals as various other environmental factors have done and such changes are unrecoverable. According to the existing tend of exploited fish individual's life history traits, we suggested further researches in this field and provided better methods of fishery management and thereby fishery resources protection than those available early. 展开更多
关键词 size composition life history fishing gear selectivity fishery management
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The application of stereo-video technology for the assessment on population change of black rockfish Sebastes schlegeli in a vessel reef area in Haizhou Bay,China 被引量:1
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作者 刘辉 许强 +2 位作者 徐勤增 张迎秋 杨红生 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第1期107-113,共7页
The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DO... The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs. 展开更多
关键词 black rockfish Sebastes schlegeli size composition ABUNDANCE stereo-video vessel reefs
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Size and elemental composition of dry-deposited particles during a severe dust storm at a coastal site of Eastern China 被引量:4
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作者 Hongya Niu Daizhou Zhang +5 位作者 Wei Hu Jinhui Shi Ruipeng Li Huiwang Gao Wei Pian Min Hu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第2期161-168,共8页
Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao(36.15°N, 120.49°E), a city located in Eastern China. The size, morpho... Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao(36.15°N, 120.49°E), a city located in Eastern China. The size, morphology, and elemental composition of the particles were quantified with a scanning electron microscope equipped with an energy dispersive X-ray instrument(SEM–EDX). The particles appeared in various shapes, and their size mainly varied from 0.4to 10 μm, with the mean diameters of 0.5, 1.5, and 1.0 μm before, during, and after the dust storm, respectively. The critical size of the mineral particles settling on the surface in the current case was about 0.3–0.4 μm before the dust storm and about 0.5–0.7 μm during the dust storm. Particles that appeared in high concentration but were smaller than the critical size deposited onto the surface at a small number flux. The elements Al, Si and Mg were frequently detected in all samples, indicating the dominance of mineral particles. The frequency of Al in particles collected before the dust storm was significantly lower than for those collected during and after the dust storm. The frequencies of Cl and Fe did not show obvious changes, while those of S, K and Ca decreased after the dust arrival. These results indicate that the dust particles deposited onto the surface were less influenced by anthropogenic pollutants in terms of particle number. 展开更多
关键词 Asian dust Dry deposition Morphology size distribution Elemental composition
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Mineralogical and Active Mechanical Excitation Characteristics of Filled Fly Ash Cementitious Materials 被引量:7
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作者 杜雨婷 WANG Hongfu +2 位作者 WANG Zhongchang WANG Zechuan XIA Hongchun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第2期413-416,共4页
To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of var... To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang's fly ash should be ground for 20 min. 展开更多
关键词 fly ash mineral composition the distribution of particle size milling time activity
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A plastidic ATP/ADP transporter gene, IbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato 被引量:3
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作者 WANG Yan-nan LI Yan +3 位作者 ZHANG Huan ZHAI Hong LIU Qing-chang HE Shao-zhen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第9期1968-1982,共15页
A plastidic adenosine triphosphate(ATP)/adenosine diphosphate(ADP) transporter(AATP) is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potentia... A plastidic adenosine triphosphate(ATP)/adenosine diphosphate(ADP) transporter(AATP) is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato(Ipomoea batatas(L.) Lam.). Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization(DP) of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants. 展开更多
关键词 sweetpotato Ib AATP starch content and composition starch granule size starch structure pasting properties
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Microstructure and Properties of Cement Foams Prepared by Magnesium Oxychloride Cement 被引量:6
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作者 王发洲 YANG Lu +1 位作者 GUAN Lingyue HU Shuguang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期331-337,共7页
Microstructural features including pore size distribution, cell walls and phase compositions of magnesium oxychloride cement foams(MOCF) with various MgO powders and water mixture ratios were studied. Their infl uen... Microstructural features including pore size distribution, cell walls and phase compositions of magnesium oxychloride cement foams(MOCF) with various MgO powders and water mixture ratios were studied. Their infl uences on compressive strength, water absorption and resistance of MOCF were also discussed in detail. The experimental results indicated that moderate and slight excess MgO powders(MgO/MgCl2 molar ratios from 5.1 to 7) were beneficial to the formation of excellent microstructure of MOCF, but increasing water contents(H2O/MgO mass ratios from 0.9 to 1.29) might result in opposite conclusions. The microstructure of MOCF produced with moderate and slight excess MgO powders could enhance the compressive strength, while serious excess MgO powders addition(MgO/MgCl2 molar ratios = 9) would destroy the cell wall structures, and therefore decrease the strength of the system. Although MOCF produced with excess MgO powders could decrease the water absorption, its softening coefficient was lower than that of the material produced with moderate MgO powders. This might be due to the instability of phase 5, the volume expansion and cracking of cell walls as immersed the sample into water. 展开更多
关键词 magnesium oxychloride cement foams pore size distribution weibull distribution function cell walls phase compositions properties
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Influence of microstructure on the corrosion resistance of Fe–44Ni thin films
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作者 Lin Lu Tian-cheng Liu Xiao-gang Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第6期691-697,共7页
An Fe–44Ni nanocrystalline(NC) alloy thin film was prepared through electrodeposition. The relation between the microstructure and corrosion behavior of the NC film was investigated using electrochemical methods an... An Fe–44Ni nanocrystalline(NC) alloy thin film was prepared through electrodeposition. The relation between the microstructure and corrosion behavior of the NC film was investigated using electrochemical methods and chemical analysis approaches. The results show that the NC film is composed of a face-centered cubic phase(γ-(Fe,Ni)) and a body-centered cubic phase(α-(Fe,Ni)) when it is annealed at temperatures less than 400℃. The corrosion resistance increases with the increase in grain size, and the corresponding corrosion process is controlled by oxygen reduction. The NC films annealed at 500℃ and 600℃ do not exhibit the same pattern, although their grain sizes are considerably large. This result is attributed to the existence of an anodic phase, Fe0.947Ni0.054, in these films. Under this condition, the related corrosion process is synthetically controlled by anodic dissolution and depolarization. 展开更多
关键词 iron nickel alloys nanocrystalline alloys thin films phase composition corrosion resistance annealing temperature grain size
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Effect of lubricant sulfur on the morphology and elemental composition of diesel exhaust particles 被引量:3
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作者 Piqiang Tan Yuan Li Hanyan Shen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第5期354-362,共9页
This work investigates the effects of lubricant sulfur contents on the morphology,nanostructure,size distribution and elemental composition of diesel exhaust particle on a light-duty diesel engine. Three kinds of lubr... This work investigates the effects of lubricant sulfur contents on the morphology,nanostructure,size distribution and elemental composition of diesel exhaust particle on a light-duty diesel engine. Three kinds of lubricant(LS-oil,MS-oil and HS-oil,all of which have different sulfur contents:0.182%,0.583% and 1.06%,respectively)were used in this study. The morphologies and nanostructures of exhaust particles were analyzed using high-resolution transmission electron microscopy(TEM). Size distributions of primary particles were determined through advanced image-processing software. Elemental compositions of exhaust particles were obtained through X-ray energy dispersive spectroscopy(EDS). Results show that as lubricant sulfur contents increase,the macroscopic structure of diesel exhaust particles turn from chain-like to a more complex agglomerate. The inner cores of the core-shell structure belonging to these primary particles change little; the shell thickness decreases,and the spacing of carbon layer gradually descends,and amorphous materials that attached onto outer carbon layer of primary particles increase. Size distributions of primary particles present a unimodal and normal distribution,and higher sulfur contents lead to larger size primary particles. The sulfur content in lubricants directly affects the chemical composition in the particles. The content of C(carbon)decreases as sulfur increases in the lubricants,while the contents of O(oxygen),S(sulfur)and trace elements(including S,Si(silicon),Fe(ferrum),P(phosphorus),Ca(calcium),Zn(zinc),Mg(magnesium),Cl(chlorine)and Ni(nickel))all increase in particles. 展开更多
关键词 Diesel exhaust particle Lubricant sulfur Morphology Nanostructure Primary particle size Elemental composition
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Sources and characteristics of fine particles over the Yellow Sea and Bohai Sea using online single particle aerosol mass spectrometer 被引量:12
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作者 Huaiyu Fu Mei Zheng +5 位作者 Caiqing Yan Xiaoying Li Huiwang Gao Xiaohong Yao Zhigang Guo Yuanhang Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第3期62-70,共9页
Marine aerosols over the East China Seas are heavily polluted by continental sources. During the Chinese Comprehensive Ocean Experiment in November 2012, size and mass spectra of individual atmospheric particles in th... Marine aerosols over the East China Seas are heavily polluted by continental sources. During the Chinese Comprehensive Ocean Experiment in November 2012, size and mass spectra of individual atmospheric particles in the size range from 0.2 to 2.0 μm were measured on board by a single particle aerosol mass spectrometer (SPAMS). The average hourly particle number (PN) was around 4560 + 3240 in the South Yellow Sea (SYS), 2900 ± 3970 in the North Yellow Sea (NYS), and 1700 ± 2220 in the Bohai Sea (BS). PN in NYS and BS varied greatly over 3 orders of magnitude, while that in SYS varied shghtly. The size distributions were fitted with two log-normal modes. Accumulation mode dominated in NYS and BS, especially during episodic periods. Coarse mode particles played an important role in SYS. Particles were dassifled using an adaptive resonance theory based neural network algorithm (ART-2a). Six particle types were identified with secondary-containing, aged sea-salt, soot-like, biomass burning, fresh sea-salt, and lead-containing particles accounting for 32%, 21%, 18%, 16%, 4%, and 3% of total PN, respectively. Aerosols in BS were relatively enriched in particles from anthropogenic sources compared to SYS, probably due to emissions from more developed upwind regions and indicating stronger influence of continental outflow on marine environment. Variation of source types depended mainly on origins of transported air masses. This study examined rapid changes in PN, size distribution and source types of fine particles in marine atmospheres. It also demonstrated the effectiveness of hi,h-time-resolution source apportionment by ART-2a. 展开更多
关键词 Source apportionment Marine aerosol size and chemical composition SPAMS East China Sea
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Haze insights and mitigation in China: An overview 被引量:12
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作者 Xuliang Zhuang Yuesi Wang +7 位作者 Hong He Jianguo Liu Xinming Wang Tingyu Zhu Maofa Ge Ju Zhou Guiqian Tang Jinzhu Ma 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第1期2-12,共11页
The present article provides an overview of the chemical and physical features of haze in China, focusing on the relationship between haze and atmospheric fine particles, and the formation mechanism of haze. It also s... The present article provides an overview of the chemical and physical features of haze in China, focusing on the relationship between haze and atmospheric fine particles, and the formation mechanism of haze. It also summarizes several of control technologies and strategies to mitigate the occurrence of haze. The development of instruments and the analysis of measurements of ambient particles and precursor concentrations have provided important information about haze formation. Indeed, the use of new instruments has greatly facilitated current haze research in China. Examples of insightful results include the relationship between fine particles and haze, the chemical compositions and sources of particles, the impacts of the aging process on haze formation, and the application of technologies that control the formation of haze. Based on these results, two relevant issues need to be addressed: understanding the relationship between haze and fine particles and understanding how to control PM2.5. 展开更多
关键词 haze secondary aerosols size distribution particles chemical composition
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Overprint of neotectonism along the course of River Chel,North Bengal,India 被引量:1
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作者 Sunipa Mandal Subir Sarkar 《Journal of Palaeogeography》 SCIE CSCD 2016年第3期221-240,共20页
This paper aims to unveit neotectonic imprints in topography, drainage and sediments in the 46.25 km tong course of the River Chet from its source down to its attuvial fan at the base of the Himatayan Mountain Front i... This paper aims to unveit neotectonic imprints in topography, drainage and sediments in the 46.25 km tong course of the River Chet from its source down to its attuvial fan at the base of the Himatayan Mountain Front in the Darjeeting-Jatpaiguri districts of India. A semi-circutar ridge detimits its primary catchment. Within confinement of this watershed basin the drainage pattern is composite being convergent atong the periphery and divergent on a butte inside. AtE these geomorphic neotectonic imprints are accom- panied by ramp and fiat structures and spectacutar mytonitization of rocks. High hypsometric index and convex shape of the hypsometric curve derived from the centrat near-straight course of the river between the primary catchment and the Main Frontat Thrust (MFT) atso reftects tectonic youthfutness of the river course. It is wett manifested atso in widety variabte stream index and stream gradient index ratios (SL/K) often exceeding 2. In response to neotectonism, this river course as a whore shifted westward between 1962 and 2007. Maximum reduction of the stream gradient on top of the MFT is etoquent enough about recent uptift of the thrust ridge. The high average stope gradient of canyon watt about 45.68° is wett consistent with this uptift. Very tow channet-width/vaUey-height ratio along the river further corroborates the uptift. The attuviat fan system of the River Chet is comprised of five morphogenetic fans stacked one above another with a tendency to shrink and shift progressively upstope. They differ from each other in terms of titt, axiat orientation, primary depositionat surface gradient and convexity in transverse section and thus present a writ of ongoing tectonism. Progressive upward increase in the share of distat crystattine rocks in ctast composition within attuviat fan package is a dear proxy for southerty advancement of the MFT. Concomitant increase in maximum ctast size is in good agreement with sediment source uptift. Art the five fans are, however, dormant now. Present-day River Chet deeply incises through ate of them and suggests further basement uplift in the context of frequent evidences of neotectonism att around, atthough the rote of climate remains uncertain in absence of adequate data. 展开更多
关键词 Uptift of Main Frontat Thrust Neotectonism Hypsometric index Stream-sradient index Atluviat fan system evotution Fan attributes Ctast size and composition
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Effects of road dust on the growth characteristics of Sophora japonica L.seedlings 被引量:1
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作者 Le Bao Laiye Qu +1 位作者 Keming Ma Lin Lin 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第8期147-155,共9页
Road dust is one of the most common pollutants and causes a series of negative effects on plant physiology. Dust's impacts on plants can be regarded as a combination of load,composition and grain size impacts on plan... Road dust is one of the most common pollutants and causes a series of negative effects on plant physiology. Dust's impacts on plants can be regarded as a combination of load,composition and grain size impacts on plants; however, there is a lack of integrated dust effect studies involving these three aspects. In our study, Sophora japonica seedlings were artificially dusted with road dust collected from the road surface of Beijing so that we could study the impacts of this dust on nitrogen/carbon allocation, biomass allocation and photosynthetic pigments from the three aspects of composition, load and grain size. The results showed that the growth characteristics of S. japonica seedlings were mostly influenced by dust composition and load. Leaf N, root–shoot ratio and chlorophyll a/b were significantly affected by dust composition and load; leaf C/N, shoot biomass, total chlorophyll and carotenoid were significantly affected by dust load; stem N and stem C/N were significantly affected by dust composition; while the dust grain size alone did not affect any of the growth characteristics. Road dust did influence the growth characteristics more extensively than loam. Therefore, a higher dust load could increase the differences between road dust and loam treatments. The elements in dust are well correlated to the shoot N, shoot C/N, and root–shoot ratio of S. japonica seedlings. This knowledge could benefit the management of urban green spaces. 展开更多
关键词 Dust composition Dust load Dust grain size Nitrogen Biomass
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PM_(2.5) in China:Measurements,sources,visibility and health effects,and mitigation 被引量:179
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作者 David Y.H.Pui Sheng-Chieh Chen Zhili Zuo 《Particuology》 SCIE EI CAS CSCD 2014年第2期1-26,共26页
Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 (particulate matter less than 2.5 μm) in 1997. The P... Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 (particulate matter less than 2.5 μm) in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices (PECD) such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s pollution in China. 展开更多
关键词 PM2.5 in ChinaAtmospheric particle size distributionPM2.5 samplingChemical composition of PM2.sSource apportionment modelsPM2.5 health impactPM2.s mitigationCoal-fired power plantParticle emission control devices (PECD)Baghouse filtrationIntegrative approach
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