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Recent Advances in Computational Simulation of Macro-,Meso-,and Micro-Scale Biomimetics Related Fluid Flow Problems 被引量:5
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作者 Y. Y. Yan 《Journal of Bionic Engineering》 SCIE EI CSCD 2007年第2期97-107,共11页
Over the last decade, computational methods have been intensively applied to a variety of scientific researches and engineering designs. Although the computational fluid dynamics (CFD) method has played a dominant r... Over the last decade, computational methods have been intensively applied to a variety of scientific researches and engineering designs. Although the computational fluid dynamics (CFD) method has played a dominant role in studying and simulating transport phenomena involving fluid flow and heat and mass transfers, in recent years, other numerical methods for the simulations at meso- and micro-scales have also been actively applied to solve the physics of complex flow and fluid-interface interactions. This paper presents a review of recent advances in multi-scale computational simulation of biomimetics related fluid flow problems. The state-of-the-art numerical techniques, such as lattice Boltzmann method (LBM), molecular dynamics (MD), and conventional CFD, applied to different problems such as fish flow, electro-osmosis effect of earthworm motion, and self-cleaning hydrophobic surface, and the numerical approaches are introduced. The new challenging of modelling biomimetics problems in developing the physical conditions of self-clean hydrophobic surfaces is discussed. 展开更多
关键词 biomimetics computational simulation macro- meso- MICRO-SCALE HYDROPHOBIC SURFACES
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Macro-and Micro-Properties of Two Natural Marine Clays in China 被引量:6
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作者 蒋明镜 彭立才 +2 位作者 朱合华 林奕禧 黄良机 《China Ocean Engineering》 SCIE EI 2009年第2期329-344,共16页
In this paper,macro-and micro-properties of natural marine clay in two different and representative regions of China are investigated in detail.In addition to in-situ tests,soil samples are collected by use of Shelby ... In this paper,macro-and micro-properties of natural marine clay in two different and representative regions of China are investigated in detail.In addition to in-situ tests,soil samples are collected by use of Shelby tubes for laboratory examination in Shanghai and Zhuhai respectively,two coastal cities in China.In the laboratory tests,macro-properties such as consolidation characteristics and undrained shear strength are measured.Moreover,X-ray diffraction test,scanning electron microscope test,and mercury intrusion test are carried out for the investigation of their micro-properties including clay minerals and microstructure.The study shows that:(1)both clays are Holocene series formations,classified as either normal or underconsolidated soils.The initial gradient of the stress-strain curves shows their increase with increasing consolidation pressure;however,the Shanghai and the Zhuhai clays are both structural soils with the latter shown to be more structured than the former.As a result,the Zhuhai clay shows strain softening behavior at low confining pressures,but strain hardening at high pressures.In contrast,the Shanghai clay mainly manifests strain-hardening.(2)An activity ranges from 0.75 to 1.30 for the Shanghai marine clay and from 0.5 to 0.85 for the Zhuhai marine clay.The main clay mineral is illite in the Shanghai clay and kaolinite in the Zhuhai clay.The Zhuhai clay is mainly characterized by a flocculated structure,while the typical Shanghai clay shows a dispersed structure.The porous structure of the Shanghai clay is characterized mainly by large and medium-sized pores,while the Zhuhai clay porous structure is mainly featured by small and medium-sized pores.The differences in their macro-and micro-properties can be attributed to different sedimentation environments. 展开更多
关键词 marine clay macro- and micro- properties comparison MICROSTRUCTURE
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Turbulence,aeration and bubble features of air-water flows in macro-and intermediate roughness conditions 被引量:2
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作者 Stefano PAGLIARA Thendiyath ROSHNI Iacopo CARNACINA 《Water Science and Engineering》 EI CAS 2011年第2期170-184,共15页
Free surface flows aeration potential causing the in macro- and intermediate flow characteristics to vary roughness conditions have a high with slopes and discharges. The underlying mechanism of two-phase flow charact... Free surface flows aeration potential causing the in macro- and intermediate flow characteristics to vary roughness conditions have a high with slopes and discharges. The underlying mechanism of two-phase flow characteristics in macro- and intermediate roughness conditions were analyzed in an experimental setup assembled at the Laboratory of Hydraulic Protection of the Territory (PITLAB) of the University of Pisa, Italy. Crushed angular rocks and hemispherical boulders were used to intensify the roughness of the bed. Flow rates per unit width ranging between 0.03 m^2/s and 0.09 m^2/s and slopes between 0.26 and 0.46 were tested over different arrangements of a rough bed. Analyses were mainly carried out in the inner flow region, which consists of both bubbly and intermediate flow regions. The findings revealed that the two-phase flow properties over the rough bed were much affected by rough bed arrangements. Turbulence features of two-phase flows over the rough bed were compared with those of the stepped chute data under similar flow conditions. Overall, the results highlight the flow features in the inner layers of the two-phase flow, showing that the maximum turbulence intensity decreases with the relative submergence, while the bubble frequency distribution is affected by the rough bed elements. 展开更多
关键词 turbulent flow aeration characteristics BOULDER macro- and intermediate roughness correlation analysis two-phase flow
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In Situ Rb-Sr Dates of Muscovite and Sulfur Isotope of Pyrite from the Yangshan Gold Deposit in Western Qinling,China
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作者 HUANG Yong QI Xianmao +10 位作者 WU Qingsong LI Jianzhong REN Minghua DUAN Liu’an XIONG Tao YANG Zhonghu ZHAO Yang CIREN Lamu WEI Wei DUAN Jilin YAN Mengmeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第5期1475-1489,共15页
Located along the southern part of the West Qinling orogenic belt,the Yangshan gold deposit is one of the largest in China.The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor nati... Located along the southern part of the West Qinling orogenic belt,the Yangshan gold deposit is one of the largest in China.The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor native gold amounts in stibnite-gold quartz veins.Pyrite and arsenopyrite are the major Au-bearing minerals.Hydrothermal muscovite from gold-bearing quartz veins was dated using the in situ Rb-Sr method to determine the formation age of the Yangshan gold deposit.The Rb-Sr isochron date of the muscovite yielded 210.1±5.6 Ma(MSWD=1.2).This date is near the lower end of the period of the mineralized granitic dykes(210.49-213.10 Ma).Two stages of gold enriching process are recognized in the gold-bearing pyrite:the first is incorporated with the Co,Cu,As,Ni enrichment;and the second is accompanied by Bi,Co,Ni,Pb,Cu,Sb concentration.The in-situ sulfur isotopic values of pyrites show a restrictedΔ34s range of-1.43‰to 2.86‰with a mean value of 0.43‰.Trace-element mapping and in-situ sulfur isotopic analysis of pyrite suggest that the sulfur deposits are likely derived from a magmatic source and likely assimilated by sulfur from the sedimentary bedrock.Thus,magmatism plays a critical role in the formation of the Yangshan gold deposit. 展开更多
关键词 Rb-Sr dating trace-element mapping sulfur isotope gold deposit Yangshan Qinling orogenic belt
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The Study of the Behaviors of Zinc and Strontium in Caries-Affected Teeth by Laser-Induced Breakdown Spectroscopy(LIBS) Technique 被引量:1
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作者 R.Nouir S.Hamzaoui +1 位作者 H.Ghalila N.Ja dane 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2020年第3期980-984,共5页
We report on the application of Laser Induced Breakdown Spectroscopy(LIBS)technique to the study of Ca,P,Zn and Sr evolutions for adult caries-affected teeth using nanosecond laser pulses.The aim of this work is to be... We report on the application of Laser Induced Breakdown Spectroscopy(LIBS)technique to the study of Ca,P,Zn and Sr evolutions for adult caries-affected teeth using nanosecond laser pulses.The aim of this work is to better understand the behaviors of Zn and Sr as trace-elements in the caries eruption with respect to the behaviors of one of the main compounds of the hydroxyapatite crystal which is the calcium.The study was focused on the investigation of these elements’evolutions from three parts of the enamel surfaces of twenty two adult caries-affected teeth;the healthy part,the dental plaque part and the caries-affected part.The decrease rates of Zn,Sr and P was,also,compared to the Ca one.Comparison concerned normalized emission line intensities.For every species,normalization was done relatively to the emission line intensities of the healthy part.Results showed that abundances of these elements decrease similarly from the healthy parts to the affected-caries parts.The higher decrease rate was noticed for the calcium.The evolutions of Zn and Sr for the three parts of the teeth surfaces cannot inform about the substitution of the calcium by these trace-elements,however the comparison of their decrease rates to the calcium one can be considered as a valuable index of this substitution. 展开更多
关键词 Teeth CARIES trace-elements SUBSTITUTION LIBS
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The influence of macronitrogen (NO_3^- and NH_4^+) addition with U lva pertusa on dissolved inorganic carbon system 被引量:1
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作者 ZHANG Naixing SONG Jinming +4 位作者 CAO Conghua REN Rongzhu WU Fengcong ZHANG Shaoping SUN Xu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第1期73-82,共10页
The influence of macronitrogen (NO3 and NH+) addition with Ulva pertusa on dissolved inorganic carbon system in seawater was studied. The results indicate that p(C02) and HCO3 concentration decrease significantly... The influence of macronitrogen (NO3 and NH+) addition with Ulva pertusa on dissolved inorganic carbon system in seawater was studied. The results indicate that p(C02) and HCO3 concentration decrease significantly, while pH and CO32- concentration increase significantly. When the con- centration of NO3 was less than 71 μmol/dm3 or NH4+ was less than 49.7μmol/dm3, dissolved inorganic carbon (DIC) absorption rates by Ulva pertusa generally increased with the increasing of nitrogen concentration. The DIC decreased 151 μmol/dm3 with the addition of 71 μmol/dm3 NO3 and decreased 232 μmol/dm3 with the addition of 49.7 μmol/dm3 NH+ after the experiment compared with DIC measured without nitrogen addition. A significant negative-correlation was found between Ac(DIC) and growth rate (#) of Ulva pertusa (r =- 0.91, P 〈0.000 1, n=11). NH+ had more influence on the species of inorganic carbon system than NO3. 展开更多
关键词 dissolved inorganic carbon ALGAE simulated experiments Ulva pertusa macro- nitrogen the Jiaozhou Bay
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Whole-Rock Geochemistry and Mineralogy of Triassic Montney Formation, Northeastern British Columbia, Western Canada Sedimentary Basin 被引量:2
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作者 Edwin I. Egbobawaye 《International Journal of Geosciences》 2016年第1期91-114,共24页
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and ... Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Results from this study indicate that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval. 展开更多
关键词 Geochemistry Whole-Rock MINERALOGY Montney Formation Thin-Section PETROGRAPHY trace-elements ICP-MS XRD DOLOMITIZATION DIAGENESIS WCSB
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Assessing volcanic origins within detrital zircon populations——A case study from the Mesozoic non-volcanic margin of southern Australia
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作者 Milo Barham Christopher L. Kirkland Martin Danisík 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第4期1371-1381,共11页
Detrital zircon U/Pb geochronology is a common tool used to resolve stratigraphic questions,inform basin evolution and constrain regional geological histories.In favourable circumstances,detrital zircon populations ca... Detrital zircon U/Pb geochronology is a common tool used to resolve stratigraphic questions,inform basin evolution and constrain regional geological histories.In favourable circumstances,detrital zircon populations can contain a concomitant volcanic contribution that provides constraints on the age of deposition.However,for non-volcanic settings,proving isolated detrital zircon grains are from contemporaneous and potentially remote volcanism is challenging.Here we use same grain(U-Th)/He thermochronology coupled with U/Pb geochronology to identify detrital zircon grains of contemporary volcanic origin.(U-Th)/He ages from Cretaceous zircon grains in southern Australia define a single population with a weighted mean age of 104±6.1 Ma.indistinguishable from zircon U/Pb geochronology and palynology(~104.0-107.5 Ma).Detrital zircon trace-element geochemistry is consistent with a continental signature for parent rocks and coupled with detrital grain ages,supports derivation from a>2000 km distant early-to mid-Cretaceous Whitsunday Volcanic Province in eastern Australia.Thus,integration of biostratigraphy,single-grain zircon double-dating(geochronology and thermochronology)and grain geochemistry enhances fingerprinting of zircon source region and transport history.A distal volcanic source and rapid continental-scale transport to southern Australia is supported here. 展开更多
关键词 PROVENANCE Grain history THERMOCHRONOLOGY Geochronology Source to sink trace-elements
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Geochemical,mineralogical,and petrological analyses for the interpretation of the sedimentary environment of the Middle-Late Ordovician Majiagou Formation(northern China)as a tool for more effective gas exploration
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作者 Jie Gao Da-Wei Lv +1 位作者 A.J.(Tom) van Loon Dun Wu 《Petroleum Science》 SCIE CAS CSCD 2022年第6期2519-2532,共14页
Core samples from the deeply buried Ordovician Majiagou Formation below the Huainan Coalfield(E China) have been investigated for their carbonate types,major and trace elements(including rare earth elements) and C and... Core samples from the deeply buried Ordovician Majiagou Formation below the Huainan Coalfield(E China) have been investigated for their carbonate types,major and trace elements(including rare earth elements) and C and O isotopes,The objective was to get a better insight into the possible occurrences of gas(and possibly oil) derived from Carboniferous coals.It was found that the carbonates are dolomites with strongly varying amounts of CaO and MgO.The low concentrations of SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)indicate deposition in a normal marine environment with little terrigenous input,The Na_(2)O/K_(2)O,Fe/Mn and Sr/Ba ratios,as well as the Ga values indicate mainly a marine salinity and a hot and humid climate.The slight depletion of Ce and Eu,the depletion of heavy rare earth elements(HREE) and the enrichment of light rare earth elements(LREE) indicate deposition in a reducing environment.It thus appears that the Majiagou Formation below the Huainan Coalfield closely resembles that in the eastern part of the Ordos Basin,where several gas reservoirs are present,so that the Majiagou Formation under the Huainan Coalfield represents a promising target for hydrocarbon exploration. 展开更多
关键词 Majiagou Formation Middle Ordovician Major-element analysis REE analysis trace-element analysis Hydrocarbon exploration
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Modeling and Mapping Forest Floor Distributions of Common Bryophytes Using a LiDAR-Derived Depth-to-Water Index
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作者 Monique Goguen Paul A. Arp 《American Journal of Plant Sciences》 2017年第4期867-890,共24页
This article describes how the cartographic depth-to-water (DTW) index in combination with other variables can be used to quantify, model and map the distribution of common forest floor bryophytes, at 1 m resolution. ... This article describes how the cartographic depth-to-water (DTW) index in combination with other variables can be used to quantify, model and map the distribution of common forest floor bryophytes, at 1 m resolution. This was done by way of a case study, using 12 terrain and climate representative locations across New Brunswick, Canada. The presence/absence by moss species was determined at each location along upland-to-wetland transects within >10-m spaced 1-m2 forest floor plots. It was found that Bazzania trilobata, Dicranum polysetum, Polytrichum commune, Hylocomium splendens, and Pleurozium schreberi had greater probabilities of occurrence in well-drained forested areas, whereas Sphagnum fuscum and Sphagnum girgensohnii dominated in low-lying wet areas. The presence/absence of each species was quantified by way of logistic regression analyses, using DTW, slope, canopy closure, forest litter depth, ecosite type (8 classes), nutrient regime (4 classes, poor to rich);vegetation type (deciduous, coniferous, mixed, and shrubs), and macro- and micro-topography (upland, wetland;mounds, pits) as predictor variables. Among these, log10DTW and forest litter depth were the most consistent predictor variables, followed by mound versus pit. For the mapping purpose, only log10DTW and already mapped classifications for upland versus wetland and vegetation type were used to predict the probability of occurrences for the most frequent moss species, namely, D. polysetum, P. schreberi and Sphagnum spp. The overall accuracy for doing this ranged from 67% to 83%, with false positives and negatives amounting to 18% to 42%. The overall classification accuracy exceeded the probability by chance alone at 76.8%, with the significance level reached at 75.3%. The average level of probability by chance alone was 60.3%. 展开更多
关键词 BRYOPHYTES Wet Areas macro- and MICRO-TOPOGRAPHY FOREST Floor FOREST LITTER Mound And Pit Canopy Closure Digital Elevation MODELING Logistic Regression
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Whole-Rock Geochemistry and Mineralogy of Triassic Montney Formation, Northeastern British Columbia, Western Canada Sedimentary Basin
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作者 Edwin I. Egbobawaye 《International Journal of Geosciences》 2016年第1期91-114,共24页
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)<span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"> </span></span><s... Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)<span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:12px;font-family:Verdana;">was used to analyze </span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">chemical elements—</span><span style="font-size:12px;font-family:Verdana;">major, trace and rare earth elements</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">(REE) concentrations, </span></span><span style="font-size:10.0pt;font-family:" color:#222222;"=""><span style="font-size:12px;font-family:Verdana;">augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for</span><span style="font-size:12px;font-family:Verdana;"> </span></span><span style="font-size:10pt;font-family:'}', serif;"><span style="font-size:12px;font-family:Verdana;">mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">Basin (WCSB). Results from this study indicate</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances</span><span style="font-size:12px;font-family:Verdana;"> </span><span style="font-size:12px;font-family:Verdana;">in the interpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are interpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, Th, U, and Cs are related to the organic matter—kerogen in the clay component of the Montney Formation source rock;and 3) transition metals—Sc, V, Co, Cr, Zn show strong affinity with diagenesis in the study interval.</span></span> 展开更多
关键词 Geochemistry Whole-Rock MINERALOGY Montney Formation Thin-Section PETROGRAPHY trace-elements ICP-MS XRD DOLOMITIZATION DIAGENESIS WCSB
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3D ordered macro-/mesoporous Ni_(x)Co_(100-x ) alloys as high-performance bifunctional electrocatalysts for overall water splitting 被引量:2
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作者 Chenhui Niu Yixin Zhang +3 位作者 Jing Dong Ruixue Yuan Wei Kou Lianbin Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第8期2484-2488,共5页
Electrochemical water splitting is a facile and effective route to generate pure hydrogen and oxygen.However,the sluggish kinetics of hydrogen evolution reaction(HER) and especially oxygen evolution reaction(OER) hind... Electrochemical water splitting is a facile and effective route to generate pure hydrogen and oxygen.However,the sluggish kinetics of hydrogen evolution reaction(HER) and especially oxygen evolution reaction(OER) hinder the water splitting efficiency.Meanwhile,the high-cost of noble-metal catalysts limit their actual application.It is thus highly urgent to exploit an economical and earthabundant bifunctional HER and OER electrocatalyst to simplify procedure and reduce cost.Herein,we synthesize the three-dimensionally ordered macro-/mesoporous(3 DOM/m) Ni_(x)Co_(100-x) alloys with distinctive structure and large surface area via a dual-templating technique.Among them,the3 DOM/m Ni61Co39 shows the lowest overpotentials of 121 mV and 241 mV at 10 mA/cm^(2) for HER and OER,respectively.Furthermore,when employed for water splitting,the Ni_(61)Co_(39) only requires 1.60 V to approach 10 mA/cm^(2) and presents excellent stability.These encouraging performances of the Ni_(61)Co_(39) render it a promising bifunctional catalyst for overall water splitting. 展开更多
关键词 macro-/mesoporous structure Ni-Co alloys Dual-templating technique ELECTROCATALYSTS Water splitting
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Macro-and Micro-Structures of Heavy Fogs and Visibility in the Dayaoshan Expressway 被引量:2
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作者 吴兑 邓雪娇 +3 位作者 毛节泰 毛伟康 叶燕翔 毕雪岩 《Acta meteorologica Sinica》 SCIE 2007年第3期342-352,共11页
Belonging to the southern subtropical moist type of monsoon climate, the Nanling mountainous area experiences heavy fogs whenever quasi-stationary fronts appear there from September to May. There can be as many as 15-... Belonging to the southern subtropical moist type of monsoon climate, the Nanling mountainous area experiences heavy fogs whenever quasi-stationary fronts appear there from September to May. There can be as many as 15-18 days of heavy fogs per month. Fogs have more serious consequences in the Lechang-Ruyuan section of the Beijing-Zhuhai Expressway (the longest expressway in China) that passes through the main part of the Nanling Mts., where the road rises from 200 m to more than 800 m above sea level (ASL). For a major motorway in the mountainous areas of Nanling Mts., two multidisciplinary integrated field observations were carried out, which measured visibility by the naked eyes, visibility by instrument, spectrum of fogdrops, liquid water content (LWC) of fog, tethered sounding, dual-parameter low-level sounding, turbulence diffusion within fog layers, aerosol spectra of size and composition, sampled fog water compositions, and sampled rainwater compositions. Typical cases were probed for their analyses of synoptics, micro- and macro-structures and microphysics. It is understood that heavy fogs take place with high frequency in the area and bring about serious consequences. Being typical advection and upslope fogs, they are in essence low-lying clouds appearing at high altitudes, which are closely related with the activity of South China frontal processes, especially the South China quasi-stationary fronts, and reflect on the role of local terrain as well. The heavy fogs are characteristic of long duration, extremely low visibility, well-organized lumpshaped structure, large-size fog-drops, moderate concentration, high LWC, and stronger turbulent diffusion within the fog layers than in fine sky. They differ much from radiation fogs, which are better documented in previous study in China. It is found that fog LWC is in significant anti-correlation with visibility so that large LWC is associated with small visual range. It is also noted that one of the reasons for the fluctuation of characteristic quantities of micro-structure such as the LWC of fog in the area is, in addition to the inhomogeneous structure of the fog itself, the effect of advection and inhomogeneous underlying surface; during the translation of fog with the ambient wind, irregular upslope and cross-over movement is another reason for the inhomogeneous structure and fluctuation of fog. The spectrum of the aerosol size displays itself as the power function of monotonous descent. The concentration of submicrometer particles is even higher. The high-concentration sulfate particles found in the aerosols of Nanling Mts. are actually good nuclei for condensation, which are favorable for the formation of fog. The presence of fog can help cleanse the trace compositions in the atmosphere so that fog droplets contain high levels of polluting elements. In the meantime, compared to cloud droplets, fog droplets are easier to be captured by the vertical surfaces of objects on the land surface, such as vegetation and buildings to constitute another kind of cleansing process. In vast stretches of forest like the Nanling Mts., this kind of cleansing may be quite important. Studying the characteristic variation of fogs in the area realistically assists in setting up a forecast and warning system for local fogs and provides basic information for fog dispersal experiments. 展开更多
关键词 Nanling mountainous areas heavy fogs VISIBILITY macro- and micro-physical features size distribution of aerosols
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Enhanced performances in catalytic oxidation of o-xylene over hierarchical macro-/mesoporous silica-supported palladium catalysts 被引量:1
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作者 Nanli QIAO Xin ZHANG +4 位作者 Chi HE Yang LI Zhongshen ZHANG Jie CHENG Zhengping HAO 《Frontiers of Environmental Science & Engineering》 CSCD 2016年第3期458-466,共9页
A series of hierarchical macro-/mesoporous silica supports (MMSs) were successfully synthesized using dual-templating technique employing polystyrene (PS) spheres and the Pluronic P123 surfactant. Pd was next load... A series of hierarchical macro-/mesoporous silica supports (MMSs) were successfully synthesized using dual-templating technique employing polystyrene (PS) spheres and the Pluronic P123 surfactant. Pd was next loaded on the hierarchical silica supports via colloids precipitation method. Physicochemical properties of the synthesized samples were characterized by various techniques and all catalysts were tested for the total oxidation of o-xylene. Among them, the Pd/MMS-b catalyst with tetraethoxysilane/polystyrene weight ratio of 1.0 exhibited superior catalytic activity, and under a higher gas hourly space velocity (GHSV) of 70000 h^-1, the 90% conversion of o-xylene has been obtained at around 200℃. The BET and SEM results indicated that Pd/MMS- b catalyst possesses high surface area and large pore volume, and well-ordered, interconnected macropores and 2D hexagonally mesopores hybrid network. This novel ordered hierarchical porous structure was highly beneficial to the dispersion of active sites Pd nanoparticles with less aggregation, and facilitates diffusion of reactants and products. Furthermore, the Pd/MMS-b catalyst possessed good stability and durability. 展开更多
关键词 hierarchical macro-/mesoporous silica palladium VOCs catalytic oxidation
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Element enrichment and U-series isotopic characteristics of the hydrothermal sulfides at Jade site in the Okinawa Trough 被引量:6
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作者 ZENG ZhiGangYU ShaoXiong YIN XueBo +3 位作者 WANG XiaoYuan ZHANG GuoLiang WANG XiaoMei CHEN DaiGeng 《Science China Earth Sciences》 SCIE EI CAS 2009年第7期913-924,共12页
The geochemical and U-series isotopic characteristics of hydrothermal sulfide samples from the Jade site (127°04.5′E, 27°15′N, water depth 1300-1450 m) at Jade site in the Okinawa Trough were analyzed. In ... The geochemical and U-series isotopic characteristics of hydrothermal sulfide samples from the Jade site (127°04.5′E, 27°15′N, water depth 1300-1450 m) at Jade site in the Okinawa Trough were analyzed. In the hydrothermal sulfide samples bearing sulfate (samples HOK1 and HOK2), the LREEs are relatively enriched. All the hydrothermal sulfide samples except HOK1 belong to Zn-rich hydrothermal sulfide. In comparison with Zn-rich hydrothermal sulfides from other fields, the contents of Zn, Pb, Ag, Cd, Au and Hg are higher, the contents of Fe, Al, Cr, Co, Ni, Sr, Te, Cs, Ti and U lower, and the 210Pb radioactivity ratios and 210Pb/Pb ratios very low. In the hydrothermal sulfide mainly composed of sphalerite, the correlations between rare elements Hf and U, and Hf and Mn as well as that between dispersive elements Ga and Zn, are strongly positive; also the contents of Au and Ag are related to Fe-sulfide, because the low temperature promotes enrichment of Au and Ag. Meanwhile, the positive correlations between Fe and Bi and between Zn and Cd are not affected by the change of mineral assemblage. Based on the 210Pb/Pb ratios of hydrothermal sulfide samples (3.99×10-5-5.42×10?5), their U isotopic composition (238U content 1.15-2.53 ppm, 238U activity 1.07-1.87 dpm/g, 234U activity 1.15-2.09 dpm/g and 234U/238U ratio 1.07-1.14) and their 232Th and 230Th contents are at base level, and the chronological age of hydrothermal sulfide at Jade site in the Okinawa Trough is between 200 and 2000 yr. 展开更多
关键词 U-SERIES isotope trace-element constituents hydrothermal sulfide JADE SITE OKINAWA TROUGH
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The antisymmetry bending theory of generalized equivalent of functionally gradient materials structure 被引量:2
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作者 李永 宋健 张志民 《Science China(Technological Sciences)》 SCIE EI CAS 2002年第4期383-394,共12页
FGM structure is defined as a kind of generalized equivalent structure according to the structure and properties of materials. This paper uses the mature plate theory and the composite material laminate theory in the ... FGM structure is defined as a kind of generalized equivalent structure according to the structure and properties of materials. This paper uses the mature plate theory and the composite material laminate theory in the analysis of FGM structure and thus puts forward a kind of new concept and a new idea. A brand-new theory, the generalized equivalent antisymmetry bending theory, which can be used to analyze the structure and properties of FGM, is formed. In addition, the correctness, reliability and foresightedness of the theory are testified through concrete analysis and calculation of the applicable FGM structure by utilizing the generalized double Fourier series solution on one hand; on the other hand, it is compared with the existing theories and experiments. 展开更多
关键词 functional gradient generalized EQUIVALENT antisymmetry macro- or meso-scopic.
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Multiple Pharmacological Actions of Yiqi Huatan Decoction(益气化痰方) in A Model of Depression in Rats 被引量:2
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作者 周海虹 陈少东 +2 位作者 徐银 韩咏竹 胡纪源 《Chinese Journal of Integrative Medicine》 SCIE CAS 2013年第3期200-205,共6页
Objective: To investigate the influence of Yiqi Huatan Decoction (益气化痰方, YHD) on a model of depression in rats under different pathological conditions. Methods: Thirty-two male SD rats were randomly divided i... Objective: To investigate the influence of Yiqi Huatan Decoction (益气化痰方, YHD) on a model of depression in rats under different pathological conditions. Methods: Thirty-two male SD rats were randomly divided into 4 groups of 8: normal, model, YHD, and maprotiline. The model group, YHD group and maprotiline group used separate feeding and rats were exposed to chronic and unpredictable stress to build the depression model. From day 2, the YHD group and maprotiline group were respectively given YHD (7 g/kg) and maprotiline (10 mg/kg) by gastrogavage once daily. The normal and model groups were given the same volume of drinking water. The medication duration were 21 days. At the end of the experiment, the serum levels of copper and zinc were determined by atomic absorption spectroscopy, plasma concentrations of adrenocorticotropic hormone (ACTH) and cortisol (COR) were detected by radioimmunoassay, and levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT) in the hypothalamus were analysed by high performance liquid chromatography-eletricochemistry. Results: Compared with the content of copper and zinc in the serum of rats in the normal group, serum copper levels in model rats were significantly increased and zinc content was significantly reduced (both P〈0.05). Plasma concentrations of ACTH and COR in the model group were significantly increased compared with those in the normal group (P〈0.05, P〈0.01). The contents of NE, DA, and 5-HT in the hypothalamus of rats in the model group were significantly reduced compared with those of the normal group (P〈0.05 or P〈0.01). Compared with those in the model group, the serum copper content and plasma concentrations of ACTH and COR were significantly decreased (all P〈0.05); meanwhile, serum zinc content and hypothalamic contents of NE, DA, and 5-HT were significantly increased in rats of the YHD group (all P〈0.05). The same effects were also shown in the maprotiline group except for 5-HT (all P〈0.05). Conclusion: The pharmacological actions of YHD for depression might be related to improving trace-element anomalies, reversing endocrine dysfunction, and modulating the disorders of monoaminergic neurotransmitters. 展开更多
关键词 Yiqi Huatan Decoction DEPRESSION endocrine dysfunction trace-element anomalies disorders of monoamine neurotransmitters
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Characterization of soil fauna under the influence of mercury atmospheric deposition in Atlantic Forest, Rio de Janeiro, Brazil 被引量:3
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作者 Andressa Cristhy Buch Maria Elizabeth Fernandes Correia +1 位作者 Daniel Cabral Teixeira Emmanoel Vieira Silva-Filho 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第6期217-227,共11页
The increasing levels of mercury(Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh count... The increasing levels of mercury(Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere.The major input of Hg to ecosystems is through atmospheric deposition(wet and dry), being transported in the atmosphere over large distances. The forest biomes are of strong importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transference to the soil through litter, playing an important role as sink of this element. Soil microarthropods are keys to understanding the soil ecosystem, and for such purpose were characterized by the soil fauna of two Units of Forest Conservation of the state of the Rio de Janeiro, inwhich one of the areas suffer quite interference from petrochemicals and industrial anthropogenic activities and other area almost exempts of these perturbations. The results showed that soil and litter of the Atlantic Forest in Brazil tend to stock high mercury concentrations, which could affect the abundance and richness of soil fauna, endangering its biodiversity and thereby the functioning of ecosystems. 展开更多
关键词 Biodiversity Litter Microarthropods Soil trace-element
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A new analytical mode and application of the laser ablation inductively coupled plasma mass spectrometer in the earth sciences 被引量:2
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作者 Yantong FENG Wen ZHANG +5 位作者 Zhaochu HU Yongsheng LIU Tao LUO Tao HE Hong LIU Kun YU 《Science China Earth Sciences》 SCIE EI CSCD 2022年第1期182-196,共15页
We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate element... We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate elemental or isotopic ratios.In order to assess the performance of the new laser analytical mode for the application in the field of earth science,we systematically investigated the elemental quantitative analysis with high spatial resolution(10μm),rapid U-Pb dating in zircons and accurate Sr-Hf isotope analysis in geological samples.The new high-frequency laser analysis technology(20 Hz,100 pulses)reduced the limit of detection(LOD)of 25 elements to 0.005-0.16μg g^(-1) with crater diameters of 10μm,which are significantly lower(decrease to 2-20%)than previous researches.The quantitative analysis of five silicate glass reference materials showed that the precision and accuracy of the 25 trace elements(with the concentration ranging from 0.17 to 683μg g^(-1))were better than 16% and 15%,respectively.The new methods raised the analytical throughput of zircon U-Pb dating,Sr isotope ratios and Hf isotope ratios to 250 analyses per hour,144 analyses per hour and 120 analyses per hour in theory,while the analytical accuracy and precision were not affected.The detailed investigations showed that the proposed new laser analytical mode has good application effects in the field of earth sciences. 展开更多
关键词 LA-ICP-MS New laser analytical mode trace-element analysis Rapid U-Pb dating Sr and Hf isotope analysis
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