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鄯科 1井是吐鲁番—哈密盆地台北凹陷首次钻穿三叠系的一口科学探索井 ,并首次在三叠系发现轻质油流。文内以鄯科 1井为例 ,运用孢粉组合、岩性组合、地震剖面、倾角测井、无机元素、地球化学等多种方法从不同侧面分析了鄯科 1井三叠系内部地层重复的现象 ,这些方法有机的结合和相互的补充打破了单一方法进行地层划分的旧模式 ,初步进行了多方法交互使用进行地质分层的尝试 ,从而有效地消除了地层划分与对比中的多解性 ,使地层划分更可靠 ,相信这些方法的交互使用在其他地区和单井的地层划分对比中也同样有较好的使用价值 相似文献
114.
Jing Zhang 《Aquatic Geochemistry》1995,1(3):241-275
Water and suspended sediment samples from the Huanghe and its delta region were analyzed to determine arsenic concentrations. Comparison with the data of previous studies and other world pristine and less disturbed rivers reveals high levels of both dissolved and particulate As in this high turbidity river. Relatively stable distribution along the river course and in delta sediment cores shows that antrhopogenic activities have not altered As concentrations by any significant magnitude since the 1940s. Therefore, high levels of As in the Huanghe should be controlled by natural weathering and lithology. In the estuary, biological removal/regeneration and abiotic events (e.g. remobilization) have been identified to cause the active (non-conservative) As distributions. With the limited data set of the present study, the abiotic and biological contributions cannot be assessed accurately, however. 相似文献
115.
Żaneta Polkowska Aleksander Astel Marzena Grynkiewicz Tadeusz Górecki Jacek Namieśnik 《Journal of Atmospheric Chemistry》2002,41(3):239-264
The paper presents monitoring results and environmental pollution assessment for the Gdask-Sopot-Gdynia Tricity (Poland), based onanalysis of precipitation. Precipitation samples were collected over a period of 12 months (January–December 1998) at ten locations in the Tricity. The following selected ions were determined in the samples:SO4
2–, F–, Cl–, NO3
–,PO4
3–, NH4
+, Na+,Mg2+, Ca2+, K+. The results were subjected to full statistical evaluation. Values of the parameters determined were correlated with each other. An attempt was made to explain co-occurrences of certain ions and the significance of their mutual effects. Pollutant concentrations and loads in precipitation were also correlated with data on wind direction and temperature in the region.Deposition of pollutants was very high in spring due to the prevailing air circulation patterns and low temperatures. Analysis of the correlations between co-occurring ions confirmed the significant impact of the location (sea coast) on the composition of rain water. Ionic ratios in rainwater were similar to those observed for sea salt samples. In addition, heavy traffic was most probably responsible for high concentrations of various forms of nitrogen and sulphates in the vicinity of major highways. 相似文献
116.
A River Water Quality Model for Chlorophyll and Dissolved Oxygen that Accommodates Zebra Mussel Metabolism 总被引:1,自引:0,他引:1
The development, testing and application of a dynamic two-dimensional (longitudinal-vertical) mass balance model for dissolved oxygen (DO) and chlorophyll (Chl) for rivers is documented that for the first time accommodates both the oxygen demand and filtering effects of zebra mussels. The test system is a phytoplankton-rich section ( 15 km long) of the Seneca River, NY, that is believed to represent an upper bound of the impact of this exotic invader. Changes in common measures of water quality of the river brought about by the zebra mussel invasion are reviewed and related longitudinal patterns in DO, Chl, and Secchi disc transparency are documented. Model testing is supported by comprehensive measurements of DO, Chl, and various forcing conditions over a three-month period, and independent determinations of several model coefficients. Wide variations in the areal consumption rate of DO (ZOD; g·m–2·d–1) and filtering rate (m3·m–2·d–1) of zebra mussels, as determined through model calibration, occurred over the study period. Values of ZOD in areas with dense zebra mussel populations at times (e.g., > 50 g·m–2·d–1) were an order of magnitude greater than the sediment oxygen demand associated with organically enriched deposits. The value of determinations of these fluxes from model calibration procedures is evaluated within the context of the limitations of protocols presently available to support independent specification of these rates. Model analyses are conducted to evaluate the relative magnitude of source and sink processes for DO and Chl, the potential operation and implications of feedback from low DO levels on oxygen consumption by zebra mussels, and the sensitivity of model simulations to selected sources of uncertainty and variability. Model projections of oxygen resources of the river are presented in a probabilistic format in evaluating reductions in zebra mussel biomass that would be necessary to eliminate violations of standards and regain assimilative capacity. 相似文献
117.
华北陆块东南缘凤台组的底部和中部存在磷结核.这些磷结核的发现表明,凤台组(至少有部分地层)可能形成于温暖的海相环境.凤台组底部与中部磷结核的地球化学特征分析表明,2个层位磷结核的沉积构造环境存在差异,凤台组底部形成于地幔活动较强的海相环境,而中部形成于地幔活动性较弱的闭塞环境. 相似文献
118.
微波辅助提取-氢化物发生原子荧光光谱法测定土壤中无机砷 总被引:1,自引:1,他引:1
建立了微波辅助提取-氢化物发生原子荧光光谱法测定土壤中无机砷的分析方法。用正交试验设计结合单因素试验优化了样品粒度、提取温度、提取时间、固液比等微波提取条件,研究了共存离子对无机砷测定的干扰情况。方法的线性范围为0.25~40.0μg/g,无机砷的检出限为0.05μg/g,样品加标回收率为92.9%~105.0%。方法的精密度(RSD,n=11)为0.3%。与水浴提取法相比,微波辅助提取法具有快速、高效的优势。方法已用于分析3个不同产地有代表性土壤中无机砷含量。 相似文献
119.
笔者是在“五国编图项目”(中国、俄罗斯、哈萨斯坦、蒙古国、韩国)的中国北方磷矿床资料研究基础之上完成本论文的。中国北方磷矿床分为“沉积型”、“沉积变质型”和“岩浆型”三大类型。沉积型磷矿床主要产生于晚震旦纪陡山沱期和早古生代寒武纪早期,磷质来源以海洋生物磷为主;沉积变质型磷矿床主要产生于中元古代,磷质来源以火山磷质为主,也可能有生物磷质参与;沉积型和沉积变质型磷矿都包含陆地风化迁入盆地中的磷成分;岩浆磷矿床主要产生于海西期和加里东期的超镁铁岩浆岩,多与铁、钒、钛成为成矿系列。沉积型磷矿在华北地台南缘和塔里木地块北缘应重视,而沉积变质型在华北地台北缘有远景;岩浆型则主要勘查超镁铁岩系列。 相似文献
120.
Robert J. Kieber Joan D. Willey Robert F. Whitehead Seth N. Reid 《Journal of Atmospheric Chemistry》2007,58(3):219-235
Significant photodegradation of chromophoric dissolved organic matter (CDOM) in rainwater was observed after exposure to simulated
sunlight. Fluorescence excitation emission spectra (EEMS) of precipitation revealed the presence of four major peaks all of
which degraded upon photolysis with the greatest loss in the region characteristic of marine CDOM. Photobleaching of absorbance
also occurred in the wavelength region between 250 and 375 nm with the greatest loss of absorbance in the upper end of the
UV-A region near 275 nm. There was a strong positive correlation between absorbance loss and total integrated fluorescence
loss suggesting these optical properties and the degree to which they are photobleached in rainwater are directly related.
The quantum yield of CDOM photodegradation in rainwater decreased dramatically with increasing wavelength and decreasing energy
of incoming radiation with the average quantum yield at 325 nm approximately an order of magnitude greater than at 460 nm.
The similarity of photolytic response between rainwater and Cape Fear estuarine CDOM indicates that some fraction of the compounds
that make up rainwater CDOM may be derived from surface sources and/or that the processes that produce or modify humic-like
substances in the atmosphere result in similar types of compounds as non-atmospheric processes. 相似文献