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91.
包气带介质截留不同龄垃圾渗滤液中的有机污染物 总被引:1,自引:0,他引:1
从渗滤液场龄和包气带岩性两方面着手,研究了不同岩性包气带介质对不同场龄渗滤液中有机污染物的截留作用规律。结果表明:新渗滤液经过以细砂、亚粘土为介质的包气带后,细砂和亚粘土中有机物的质量分数分别从0.70%和0.87%增大至0.80%和1.00%以上,而老渗滤液使细砂和亚粘土中有机物的质量分数降至0.70%和0.50%以下。新渗滤液经过包气带后,包气带介质中有机物的含量增大,而老渗滤液使包气带介质中有机物的含量降低,亚粘土较细砂更容易受到渗滤液污染的影响。即渗滤液性质对包气带介质中有机物含量具有方向性的影响作用,而包气带介质亚粘土比细砂更容易放大这种作用效果。 相似文献
92.
In this paper, the data on the paleoclimatic and paleoenvironmental changes during the Holocene are presented and a discussion
is made on a 225-cm-long sediment core from Ulungur Lake, located in Northwest China. The chronology is constructed from six
AMS radiocarbon dates on the bulk organic matter. On the basis of the analysis of ostracod assemblages and the shell stable
isotopes, the core is divided into three paleoclimatic and paleoenvironmental evolution stages: 9 985–5 250 cal.aB.P. stage
is the wettest phase of the core section. The climate changed from moderate-dry to cool-wet, and then to warm-wet in turn,
and the lake level rose accordingly, showing the characteristic of a high lake level. 5 250–1 255 cal.aB.P. stage was the
driest phase of the core sediment. The climate turned from the early warm-dry to the late warm-wet and the lake level fell
and rose again. Finally, the 1 255 cal.aB.P. stage was the medium stage of the section. The temperature was low and then increased
after the 1920s and the climate was dry. The whole climatic and environmental evolution records of Lake Ulungur were not only
in agreement with the sporopollen record of the same core but also in agreement with the record of environmental changes of
adjacent areas. It responded to regional environmental changes and global abrupt climate events, following the westerly climate
change mode on 100-year-scale, primarily with cold-wet and warmdry characteristics.
__________
Translated from Quaternary Sciences, 2007, 27(3):382–391 [译自:第四纪研究] 相似文献
93.
封闭体系有机质与有机碳氢氮恢复动力学研究 总被引:3,自引:0,他引:3
在封闭体系的条件下,对典型的Ⅰ、Ⅱ、Ⅲ型干酪根在热演化过程中的损失进行生烃动力学研究,获得了Ⅰ、Ⅱ、Ⅲ型干酪根的总量、有机碳、氢以及氮质量损失动力学参数。用Kinetics软件计算了封闭体系干酪根有机碳丰度、氢碳原子比和氮碳原子比的恢复系数。认为在对高成熟—过成熟干酪根进行生烃评价时,Ⅰ、Ⅲ型干酪根残余有机碳丰度需要进行恢复,而Ⅱ型干酪根残余有机碳丰度不需要恢复。三种类型干酪根的氢碳原子比均需要进行恢复。 相似文献
94.
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
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
95.
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
96.
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
97.
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
98.
在"碳中和"目标的驱动下,全球能源系统向清洁化、低碳化甚至无碳化发展已是大势所趋。针对向清洁能源转型的需求,采用了统计对比、分类汇总、综合分析等方法,分析研究了关键矿产在电池、电网、低碳发电和氢能等行业中的作用和需求。结合当前关键矿产产量的地理集中度高、项目开发周期长、资源质量下降等矿产供应和投资计划不能满足清洁能源转型的需求等问题,提出确保关键矿产多样性供应,推动价值链各环节的技术创新,扩大回收利用,增强供应链弹性和市场透明度,将更高的环境、社会和治理标准纳入主流程及加强生产者和消费者之间的国际合作等建议。 相似文献
99.
Particulate content of savanna fire emissions 总被引:9,自引:0,他引:9
Hélène Cachier Catherine Liousse Patrick Buat-Menard Annie Gaudichet 《Journal of Atmospheric Chemistry》1995,22(1-2):123-148
As part of the FOS-DECAFE experiment at Lamto (Ivory Coast) in January 1991, various aerosol samples were collected at ground level near prescribed fires or under local background conditions, to characterize the emissions of particulate matter from the burning of savanna vegetation. This paper deals with total aerosol (TPM) and carbon measurements. Detailed trace element and polycyclic hydrocarbon data are discussed in other papers presented in this issue.Near the fire plumes, the aerosols from biomass burning are primarily of a carbonaceous nature (C%70% of the aerosol mass) and consist predominantly of submicron particles (more than 90% in mass.) They are characterized by their organic nature (black to total carbon ratio Cb/Ct in the range 3–20%) and their high potassium content (K/Cb0.6). These aerosols undergo aging during their first minutes in the atmosphere causing slight alterations in their size distribution and chemical composition. However, they remain enriched in potassium (K/Cb=0.21) and pyrene, a polycyclic aromatic hydrocarbon, such that both of these species may be used as tracers of savanna burning aerosols. We show that during this period of the year, the background atmosphere experiences severe pollution from both terrigenous sources and regional biomass burning (44% of the aerosol). Daynight variations of the background carbon concentrations suggest that fire ignition and spreading occur primarily during the day. Simultaneous TPM and CO2 real-time measurements point to a temporal and spatial heterogeneity of the burning so that the ratio of the above background concentrations (TPM/CO2) varies from 2 to 400 g/kg C. Smoldering processes are intense sources of particles but particulate emissions may also be important during the rapidly spreading heading fires in connection with the generation of heavy brown smoke. We propose emission factor values (EF) for aerosols from the savanna biomass burning aerosols: EF (TPM)=11.4±4.6 and 69±25 g/kg Cdry plant and EF(Ct)=7.4±3.4 and 56±16 g C/kg Cdry plant for flaming and smoldering processes respectively. In these estimates, the range of uncertainty is mostly due to the intra-fire variability. These values are significantly lower than those reported in the literature for the combustion of other types of vegetation. But due to the large amounts of vegetation biomass being burnt in African savannas, the annual flux of particulate carbon into the atmosphere is estimated to be of the order of 8 Tg C, which rivals particulate carbon emissions from anthropogenic activities in temperate regions. 相似文献
100.
烂泥沟金矿是以浊积岩为容矿岩石的微细浸染型金矿。有机岩石学分析表明,矿石与围岩中干酪根类型无明显差别,同属腐泥-腐植型。与围岩相比,矿石中干酪根成熟度(R0=2.74%-3.06%)和含金性(6.15-24.8μg/g)均较高;干酪根总含金量在全岩中所占的比例是围岩高于矿石。氯仿沥青“A”的检测说明,矿石样品中可溶性有机质形成于强还原和高盐度环境,沥青质和含硫有机化合物发育。研究认为,干酪根含金性与碳的活化有关;不饱和的有机基因对金的动一定转换可能具有重要意义。 相似文献