金岭寺—羊山盆地北票组烃源岩特征   总被引：2，自引：0，他引：2  

何保李茂丰  刘颖鑫 《中国煤炭地质》2008,20(3):25-27

通过对采集的岩样进行地球化学综合分析,得出金羊盆地北票组为盆地主要烃源岩,为盆地油气生成提供了物质基础;北票组烃源岩有机质丰度不高,属差一中等烃源岩;干酪根类型以腐殖型为主,成烃母质为陆地高等植物：金羊盆地北票组烃源岩已经进入成烃门限．并处于成熟阶段中的低成熟到中成熟阶段。  相似文献   

A dynamic box model of bioactive elements in the southern Taiwan Strait   总被引：3，自引：0，他引：3  

洪华生  商少凌 《中国海洋湖沼学报》1994,12(2):120-129

A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO_4-P,NO_3-N,AOU,POC and PON in the southern Taiwan Strait region based on field data of the"Minnan Taiwan Bank Fishing Ground Upwelling Ecosystem Study" during the period of Dec.1987-Nov.1988.According to the unique hydrological and topographical features of the region,six boxesand three layers were considered in the model.The variation rates and fluxes of elements induced by hor-izontal current,upwelling,by diffusion,sinking of particles and biogeochemical processes were estimatedrespectively.Results further confirmed that upwellings had important effects in this region.Thenearshore upwelling areas had net input fluxes of nutrients brought by upwelling water,also had high de-pletion rates of nutrients and production rates of particulate organic matter and dissolved oxygen.Theabnormal net production of nutrients in the middle layer(10-30m) indicated the important role of bacte-ria in this high production region.Th  相似文献   

Molecular and bulk isotopic analyses of organic matter in marls of the Mulhouse Basin (Tertiary, Alsace, France)     

Hollander DJ  Sinninghe Damste JS  Hayes JM  de Leeuw JW  Huc AY 《Organic Geochemistry》1993,20(8):1253-1263

Contents of 13C in kerogens and carbonates in 21 samples from a core of the MAX borehole, Mulhouse Evaporite Basin, range from -27.3 to -23.5 and -3.7 to -1.8% vs PDB, respectively. Organic nitrogen in the same samples is enriched in 15N relative to atmospheric N2 by 12.2-15.7%. Hydrogen indices and delta values for kerogens vary systematically with facies, averaging 493 mg HC/g Corg and -25.7% in the most saline facies (dominated by inputs from aquatic sources) and 267 mg HC/g Corg and -23.7% in the least saline facies (50/50 aquatic/terrigenous). Values of delta were measured for individual aliphatic hydrocarbons from three samples representing three different organic facies. For all samples, terrigenous inputs were unusually rich in 13C, the estimated delta value for bulk terrigenous debris, apparently derived partly from CAM plants, being -22.5%. In the most saline facies, isotopic evidence indicates the mixing of 13C-depleted products of photosynthetic bacteria with 13C-enriched products of halotolerant eukaryotic algae. At lower salinities, a change in the producer community is marked by a decrease in the 13C content of algal lipids. The content of 13C in algal lipids increases in the least saline facies, due either to succession of different organisms or to decreased concentrations of dissolved CO2.  相似文献   

The “Zero-order Model” revisited: Paul Schindler's influence on the development of trace metal scavenging models     

Santschi  Peter H.  Honeyman  Bruce D.  Quigley  Matthew S. 《Aquatic Sciences - Research Across Boundaries》1993,55(4):230-239

In 1975 Paul Schindler produced the first oceanic trace metal scavenging model to explicitly include the role of surface chemistry as a control on trace metal water column residence times. The eighteen years that have elapsed since the publication of Schindler's seminal paper have seen the development of a variety of oceanic scavenging models; yet, the fundamental insight of his Zero-order Model remains the benchmark. This paper describes the role of Paul Schindler's work on surface chemistry in providing a framework for the current generation of trace element scavenging models.  相似文献   

Diagenesis of vascular plant organic matter components during burial in lake sediments   总被引：12，自引：0，他引：12  

Philip A. Meyers  Mary J. Leenheer  Richard A. Bourbonniere 《Aquatic Geochemistry》1995,1(1):35-52

Diagenetic changes are difficult to distinguish from variations in sources of organic matter to sediments. Organic geochemical comparisons of samples of wood, bark, and needles from a white spruce (Picea glauca) living today and one buried for 10,000 years in lake sediments have been used to identify the effects of diagenesis on vascular plant matter. Important biogeochemical changes are evident in the aged spruce components, even though the cellular structures of the samples are well preserved. Concentrations of total fatty acids dramatically diminish; unsaturated and shorter chainlength components are preferentially lost from the molecular distributions. Concentrations of total alcohols are similar in the modern and 10,000-year-old wood and bark but markedly lowered in the aged needles. Hydrocarbon concentrations and distributions show little diagenetic change in the 10,000-year-old plant materials. Cellulose components in the wood decrease relative to lignin components, although both types of materials remain in high concentration in comparison to other organic components. Aromatization of abietic acid proceeds more rapidly in buried spruce wood than in bark; retene is the dominant polyaromatic hydrocarbon in the aged wood. In contrast to the variety of changes evident in molecular compositions, neither ¹³C values nor C/N ratios differ significantly in the bulk organic matter of modern and aged spruce components.  相似文献   

我国藻菌生物成因的金矿研究   总被引：1，自引：0，他引：1  

帅德权  胡晓强 《黄金地质》1995,1(2):1-8

生物成矿作用分为生物直接成矿作用和生物间接成矿作用,生物直接成矿作用的标志结构为生物有机胶体结构。生物间接成矿作用的标志结构为“矿交代生物”结构,我国陕西二台子－半仓沟金矿,四川东北寨金矿、川甘拉尔玛金矿和云南金厂金矿等均为典型为实例,矿石中普遍含有多种金属矿物生物结构,还含多种生物有机组分。成矿物质具有多源性特征,硫同位素具混合型特征,矿床成型机制可与“人工碳吸附系统”聚金机制相类比,含金层位可  相似文献   

Associations and mobility of uranium in soils near a depleted uranium （DU） weapons testing site, SW Scotland     

Margaret C. Graham John G. Farmer Ian W. Oliver Angus B. MacKenzie Robert M. Ellam 《中国地球化学学报》2006,25(B08):112-112

Natural uranium has three isotopes, ^238U, ^235U and ^234U, with natural abundances of 99.27 atom %, 0.72% and 0.0055%, respectively. Only ^235U is fissile and the production of nuclear fuel and nuclear weapons involves enrichment of uranium in ^235U. This process also results in separation of ^234U from ^238U, leaving depleted uranium （DU）, with typical ^234U/^238U and ^235U/^238U activity ratios of about 0.19 and 0.013, respectively, as a waste product. The high density, high melting and boiling points and chemical stability of uranium and the availability of DU in relatively pure form mean that DU has many uses, including armour-piercing munitions. Such munitions have been developed in the UK since the 1960s and testing has been carried out by the Ministry of Defence （MoD） at firing ranges such as Dundrennan, SW Scotland and Eskmeals, NW England. The firing of DU munitions can result in the dispersion of DU and its combustion products （oxides） as aerosols or as larger fragments, with the potential for human exposure either directly at the site of detonation or via post-depositional migration in the environment. The aim of this work was to investigate the potential environmental mobility of DU by characterizing the associations of U in soil porewaters with increasing distance from a firing site. To this end, several soil cores located down-wind of the firing site at Dundrennan, near Kirkcudbright, SW Scotland, were collected in May 2006. These were sectioned on-site into 1- or 2-cm depth intervals and porewaters were isolated by centfifugation （10 minutes; 8873 g） on return to the laboratory. Following filtration through 0.2-micron cellulose nitrate filters, the porewaters were analyzed by ICP-QMS （U concentration） and ICP-OES （Fe, Al, Ca, Mg, Mn concentrations）. Sub-samples were also subjected to centrifugal ultrafiltration （100, 30, and 3 kD） and to gel electrophoretic fractionation （agarose; 0.045 M Tris-borate; 20 mA, 30 minutes）. Results showed that U was present at up to 4 μg/L in the soil porewater and that the associations of U varied with sample location and soil depth.  相似文献   

Effects of low molecular weight organic acids on sorption and desorption behavior of p-chlorophenol by yellow earth     

Daoyong ZHANG Xiangliang PAN Shuimu LIAO Chenglin HUANG Jingmei ZHANG 《中国地球化学学报》2006,25(B08):133-133

Low molecular weight organic acids （LMWOAs） are important components of root exudates. They play an important role in immobilizing and remobilizing contaminants in rhizospheric soil. Effects of four LMWOAs on the sorption and desorption behavior of p-chlorophenol by yellow earth was studied in batch mode. The results showed that the previous application of LMWOAs to enhanced adsorption capacity of p-chlorophenol of the soil in the order of maleic acid〉malic acid〉oxalic acid〉citric acid. However, when LMWOAs were applied to soil where p-chlorophenol had been previously adsorbed, substantial p-chlorophenol was desorbed from soil by oxalic acid, whereas citric acid, malic acid and maleic acid didn＇t desorb as much p-chlorophenol from soil as deionized water.  相似文献   

Origin and three-dimensional fluorescence spectrum of the chromophoric dissolved organic matter in Yangtze estuary, East China     

Fan YANG Qinghui HUANG Jianhua LI Xiaomin ZHU 《中国地球化学学报》2006,25(B08):262-262

Dissolved organic matter （DOM） is an important chemical component in natural water. Chromophoric dissolved organic matter （CDOM）, a fraction of optical properties, plays art important role in the biogeochemical cycle of nutrients in aquatic environment. People realized that DOM cycle is crucial in the global carbon and nitrogen flux, and also is inherently related to nutrients and trace metal elements. Therefore, CDOM was concerned by scientists in global oceanography and limnology fields. Water samples were collected from three sections （North Channel, South Channel and Zhuyuan） of the Yangtze （Changjiang River） estuary in March 2006 Three-dimensional excitation emission matrix （3-DEEM） fluorescence spectra were analyzed for those filtrates through Whatman GF/F filters. Dissolved organic carbon （DOC） was also measured by TOC analyzer. The tidal variety was also taken into account. The 3-D EEM fluorescence scans suggested the fluorescence characteristics of humic acid （Ex=332-344 nm, Em=439-451 nm） and fulvic acid （Ex=250-254 nm, Em=472-478 nm） were obvious, and the fluorescence group of protein-like and tyrosine （Ex=230 nm, Em=283 nm） was also found. They are mainly composed of CDOM in the Yangtze estuary. Further data analysis, especially the fluorescence index （f 450/500）, showed that terrestrial signal was rather strong （1.41-1.65） in the surface water, however, some terrestrial CDOM signals of bottom water showed excursions （1.28-1.39）. On the other hand, anthropogenic sign was impressed in the waters of Zhuyuan, which is one of the main drain outlets of Shanghai Metropolis. DOC concentrations ranged from 2.2 mg/L to 3.4 mg/L in Zhuyuan and South Channel, and from 2.0 mg/L to 2.4 mg/L in North Channel. The tide effect played a role in the composition of the CDOM measured by 3-D fluorescence scan technology.  相似文献   

紫色丘陵区不同土地利用方式下土壤活性有机碳垂直分布特征     

《山地学报》2006,24(B10):21-26

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