Mass Concentration and Mineralogical Characteristics of Aerosol Particles Collected at Dunhuang During ACE-Asia     

沈振兴  曹军骥  李旭祥  王亚强  张小曳 《大气科学进展》2006,23(2):291-298

Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The mean mass concentrations of total suspended particle matter during the spring of 2001 and 2002 were 317 μg m?3 and 307 μg m?3, respectively. Eleven dust storm events were observed with a mean aerosol concentration of 1095 μg m?3, while the non-dusty days with calm or weak wind speed had a background aerosol loading of 196 μgm?3 on average in the springtime. The main minerals detected in the aerosol samples by X-ray diffraction were illite, kaolinite, chlorite, quartz, feldspar, calcite and dolomite. Gypsum, halite and amphibole were also detected in a few samples. The mineralogical data also show that Asian dust is characterized by a kaolinite to chlorite (K/C) ratio lower than 1 whereas Saharan dust exhibits a K/C ratio larger than 2. Air mass back-trajectory analysis show that three families of pathways are associated with the aerosol particle transport to Dunhuang, but these have similar K/C ratios, which further demonstrates that the mineralogical characteristics of Asian dust are different from African dust.  相似文献   

柞水银铅矿地表径流沉积物中污染物相态分析     

李英  曹军骥 《地球科学与环境学报》1998,20(1):9

采自柞水银铅矿地表径流６个沉积物样品,用连续提取法提取了金属元素的５种化学相态（可交换相、碳酸盐相,铁锰氧化物结合相,有机质－硫化物结合相及残渣相）,测定了各相中铜铅锌含量,分析了其分布特征。结果表明,在河流沉积物中,铜主要以残渣相和有机质相存在,铅、锌主要为铁锰水合氧化物相和碳酸盐相。在此基础上,对矿山开采中环境影响进行了讨论。  相似文献   

任丘油田开发过程中油田水水质演化特征研究     

陈锁忠  余俊吉 《高校地质学报》1998,4(3):338-345

对任丘油田开发过程中油田水水质特征及演化规律进行了初步分析,探讨了人工注水对油田水质的演化影响,其结果表明,注入水对油田水泊稀释混合作用明显,破坏了油层内部水－岩作用平衡,改变了井下原来的水文地球化学环境,根据诺模图求得的一些离子含量与其实际值之间存在明显差异,表明机械混合与水－岩相互作用并存,这与实际情况是吻合的。  相似文献   

Clinoamphibole lamellae in diopside of garnet lherzolite from Alpe Arami,Bellinzona, Switzerland     

Yoshiaki Yamaguchi  Junji Akai  Katsutoshi Tomita 《Contributions to Mineralogy and Petrology》1978,66(3):263-270

Porphyroclastic diopside in garnet lherzolite from Alpe Arami, Bellinzona, Switzerland includes optically-visible clinoamphibole lamellae with a composition intermediate between pargasite and edenite. X-ray and electron microscopic observations show that the diopside crystal contains sub-microscopic thin clinoamphibole lamellae parallel to (010), which have coherent interfaces to the host. A kind of planar defect parallel to (010) in clinopyroxene structure, as suggested by Chisholm (1973), is shown here to correspond to intercalation of a 9 Å lattice fringe of double-chain structure in the electron micrograph of the diopside. The thin clinoamphibole lamellae are observed to be segregated domains consisting of two and more 9 Å fringes.From the chemical characteristics and textural relations of the development of such clinoamphiboles, the chemical change required to form them is considered to have been caused principally by decreasing solubility of atoms such as Na, Al and Cr in clinopyroxene structure during the retrogressive reequilibration. Also, a possibility of finite solid solution of clinoamphibole in clinopyroxene is discussed.  相似文献   

Early diagenesis of fatty acids in lacustrine sediments—II. A statistical approach to changes in fatty acid composition from recent sediments and some source materials     

Hiromi Matsuda  Tadashiro Koyama 《Geochimica et cosmochimica acta》1977,41(12):1825-1834

The percentage composition and total amounts of fatty acids from plankton, live and dead plants (waterweeds and higher plants) and a forest soil, considered as possible origins of autochthonous and allochthonous organic materials in lacustrine sediments, have been determined by gas-liquid chromatography. Statistical analyses were carried out by computing distance index of the fatty acid composition between these source materials and the uppermost sediment from Lake Suwa, and the composition diversity index (CDI) of fatty acids in the recent sediments from Lake Suwa.The distance index indicated that the fatty acid composition in the uppermost sediment is similar to those in diatoms, Zooplankton and forest soil, and the values for dead leaves were smaller than for live ones. It suggests that the autolysis and/or decomposition processes prior to deposition onto the top sediment makes the fatty acid composition of organic debris similar to the uppermost sediment. The CPI in recent sediments varied irregularly, whereas the CDI increased during early diagenesis to yield a value comparable to ancient sediments.  相似文献   

Dependence of the build-up of the colour–magnitude relation on cluster richness at z∼ 0.8     

Yusei Koyama  Tadayuki Kodama  Masayuki Tanaka  Kazuhiro Shimasaku  Sadanori Okamura 《Monthly notices of the Royal Astronomical Society》2007,382(4):1719-1728

  相似文献   

岱海与太湖沉积物焦碳和烟炱最近200年历史对比研究   总被引：2，自引：0，他引：2       下载免费PDF全文

韩永明  曹军骥  金章东  刘随心  安芷生 《第四纪研究》2010,30(3)

黑碳是不完全燃烧产生的一种难熔的含碳物质的连续统一体,由焦碳(char)和烟炱(soot)组成.岱海与太湖沉积物焦碳和烟炱浓度对比显示,两个湖泊焦碳浓度和通量变化受局地火事件影响,无明显的规律; 而烟炱具有相似的变化历史,主要反映在1970年代后期急剧升高,与中国工业化历史一致.烟炱粒径细小,具区域传输特点,可以通过沉积物指示大气烟炱.结合当前大气气溶胶烟炱浓度,恢复了岱海与太湖地区最近200年来的大气烟炱浓度.其变化趋势与200年来北半球温度对比显示,大气烟炱中的高浓度对应于高温,低浓度对应低温.这种历史关系进一步证实大气烟炱在全球增温中具有极其重要的作用.  相似文献   

Construction of Structural Geological Model Using Monte Carlo Simulation     

Xavier  Bruna Catarino  Egydio-Silva  Marcos  Sadowski  Georg Robert  de Assis Silva  Bruno  Takara  Victor Junji 《Geotechnical and Geological Engineering》2022,40(3):1345-1361

Geotechnical and Geological Engineering - To optimize the prediction of structural geological conditions in the underground as of data collected at the surface, due to the usual great uncertainties...  相似文献   

The heterogeneous condensation of interstellar ice grains     

Junji Seki  Hiroichi Hasegawa 《Astrophysics and Space Science》1983,94(1):177-189

Processes of heterogeneous condensation are investigated. We consider the situation that vapor and solid grains of which material is other than that of the vapor coexist and the saturation of the vapor increases with time. If the contact angle of the condensate to the solid is small (?90°), the condensate will be formed as mantles coating the solid grains but only a fraction of the solid grains will be coated by mantles. The ratio of core-mantle grains to bare solid grains in number will be smaller as the density of the vapor and the time scale of saturation increase are large. Actual calculations are made by adopting H₂O ice as the mantle material and magnesium silicate as the core material.  相似文献   

Continuous Measurement of Number Concentrations and Elemental Composition of Aerosol Particles for a Dust Storm Event in Beijing   总被引：1，自引：0，他引：1  

ZHANG Renjian  HAN Zhiwei  SHEN Zhenxing  CAO Junji 《大气科学进展》2008,25(1):89-95

A continuous measurement of number size distributions and chemical composition of aerosol particles was conducted in Beijing in a dust storm event during 21-26 March 2001. The number concentration of coarse particles （ 〉2μm） increased more significantly than fine particles （ 〈2μm） during the dust storm due to dust weather, while the anthropogenic aerosols collected during the non-dust-storm period tended to be associated with fine particles. Elemental compositions were analyzed by using proton-induced X-ray emission （PIXE）. The results show that 20 elements in the dust storm were much higher than in the non-dust-storm period. The calculated soil dust concentration during the dust storm was, on average, 251.8μg m^-3, while it was only 52.1μg m^-3 on non-dust-storm days. The enrichment factors for Mg, A1, P, K, Ca, Ti, Mn, Fe, C1, Cu, Pb, and Zn show small variations between the dust storm and the non-dust-storm period, while those for Ca, Ni and Cr in the dust storm were much lower than those in the non-dust-storm period due to significant local emission sources. A high concentration and enrichment factor for S were observed during the dust storm, which implies that the dust particles were contaminated by aerosol particles from anthropogenic emissions during the long-range transport. A statistical analysis shows that the elemental composition of particles collected during the dust storm in Beijing were better correlated with those of desert soil colleted from desert regions in Inner Mongolia. Air mass back-trajectory analysis further confirmed that this dust storm event could be identified as streaks of dust plumes originating from Inner Mongolia.  相似文献