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93.
长庆气田奥陶系风化壳气藏、气源研究 总被引:18,自引:4,他引:18
对10年来长庆气田奥陶系风化充气藏气源问题存在的不同观点(上古生界煤成气和奥陶系海相碳酸盐岩气何者为主)及相应的证据进行了总结和讨论,认为“奥陶系自生自储为主”的观点对地质和地球化学现象的解释存在疑问,包括用次要组分来判别混源天然气的主要来源,用不确切的端员气地球化学特征来计算混源比,对本溪组底部岩石的封盖性和下奥陶统碳酸盐岩的原始生烃潜力评价偏高,忽略了石炭系存在能够生成油型气的海相源岩。因此,长庆气田不能作为海相贫有机质的碳酸盐岩生成的大、中型油气田的实例。根据天然气及气源岩的地球化学特征,提出长庆气田奥陶系风化壳气藏气是以上古生界煤成气为主、石炭系海相源岩生成的油型气为辅的混合气。 相似文献
94.
Analysis on hydrochemical characteristics of groundwater in strongly exploited area in Hutuo River Plain 下载免费PDF全文
The Hutuo River alluvial-proluvial fan is located in North China Plain, and groundwater is the main source of water supply for agriculture and domestic water. Shijiazhuang depression funnels due to the long-term excessive exploitation are the bottleneck of the regional economic development. Analyzing the chemical characteristics of groundwater under the condition of strong human activities, can provide a scientific basis for further study of strong groundwater mining area environmental change. 143 groups of shallow groundwater samples are collected during the period of 2007-2008. In this paper, the hydrochemical characteristics of groundwater in the Hutuo River Plain area are analyzed systematically, using hydrogeochemical theory, combined with statistical methods and hydrochemical methods. Results are shown as follows: HCO_3~- and Ca~(2+) are major anion and cation. The variation coefficients of K~+, Ca~(2+), Mg~(2+) and HCO_3~- between 0.25 and 0.52, which means small and stable relatively. The variation coefficient of are Na~+, NO_3~-, Cl-, SO2-4 were large(0.89-1.01). They are sensitive and vulnerable to environmental change affect. Due to the impact of human activities, from the top to the edge of the alluvial-proluvial fan, the hydrochemical types of groundwater change from single to multiple, followed by HCO_3~-Ca·Mg, HCO_3·SO_4-Ca·Mg, HCO_3·SO_4·Cl-Ca·Mg, HCO_3·Cl-Ca·Mg and other types. 相似文献
95.
大尺度水循环模拟系统不确定性研究进展(英文) 总被引:1,自引:1,他引:1
The regional hydrological system is extremely complex because it is affected not only by physical factors but also by human dimensions.And the hydrological models play a very important role in simulating the complex system.However,there have not been effective methods for the model reliability and uncertainty analysis due to its complexity and difficulty.The uncertainties in hydrological modeling come from four important aspects:uncertainties in input data and parameters,uncertainties in model structure,uncertainties in analysis method and the initial and boundary conditions.This paper systematically reviewed the recent advances in the study of the uncertainty analysis approaches in the large-scale complex hydrological model on the basis of uncertainty sources.Also,the shortcomings and insufficiencies in the uncertainty analysis for complex hydrological models are pointed out.And then a new uncertainty quantification platform PSUADE and its uncertainty quantification methods were introduced,which will be a powerful tool and platform for uncertainty analysis of large-scale complex hydrological models.Finally,some future perspectives on uncertainty quantification are put forward. 相似文献
96.
为揭示波浪扰动对湖泊底泥磷释放的影响,在波浪水槽中模拟了不同波高情况下扰动对水体、水土界面、底泥间隙水的磷、溶解氧等的影响.结果显示,在大波扰动下,沉积物大量悬浮,水体总磷随之增加,溶解性磷增加却不显著;波浪扰动显著增加了水体和沉积物界面的溶解氧浓度,并增加了溶解氧在沉积物的侵蚀深度;波浪扰动降低了沉积物表层10 cm内间隙水中的磷浓度,而10 cm以下沉积物中间隙水中磷浓度基本保持不变.研究表明,波浪扰动可迅速增加水体中颗粒态的营养盐,但是对于溶解态营养盐,尤其是水体中活性磷浓度的影响,则受沉积物性质、水-沉积物间隙水磷浓度差,以及水-沉积物中氧含量等多方面因素的影响. 相似文献
97.
Early Cambrian and Mid-Late Neoproterozoic volcanic rocks in China are widespread on several Precambrian continental blocks,which had aggregated to form part of the Rodinia supercontinent by ca.900 Ma.... 相似文献
98.
Characteristics of dry-wet abrupt alternation events in the middle and lower reaches of the Yangtze River Basin and the relationship with ENSO 总被引:1,自引:0,他引:1
During recent decades, more frequent flood-drought alternations have been seen in China as a result of global climate change and intensive human activities, which have significant implications on water and food security. To better identify the characteristics of flood-drought alternations, we proposed a modified dry-wet abrupt alternation index (DWAAI) and applied the new method in the middle and lower reaches of the Yangtze River Basin (YRB-ML) to analyze the long-term spatio-temporal characteristics of dry-wet abrupt alternation (DWAA) events based on the daily precipitation observations at 75 rainfall stations in summer from 1960 to 2015. We found that the DWAA events have been spreading in the study area with higher frequency and intensity since 1960. In particular, the DWAA events mainly occurred in May and June in the northwest of the YRB-ML, including Hanjiang River Basin, the middle reaches of the YRB, north of Dongting Lake and northwest of Poyang Lake. In addition, we also analyzed the impact of El Niño Southern Oscillation (ENSO) on DWAA events in the YRB-ML. The results showed that around 41.04% of DWAA events occurred during the declining stages of La Niña or within the subsequent 8 months after La Niña, which implies that La Niña events could be predictive signals of DWAA events. Besides, significant negative correlations have been found between the modified DWAAI values of all the rainfall stations and the sea surface temperature anomalies in the Nino3.4 region within the 6 months prior to the DWAA events, particularly for the Poyang Lake watershed and the middle reaches of the YRB. This study has significant implications on the flood and drought control and water resources management in the YRB-ML under the challenge of future climate change. 相似文献
99.
封装型的特征选择算法相对于过滤算法而言更有助于提高分类精度,因此在当前计算技术及效率快速发展的背景下必将成为未来之趋势。本文以支持向量机(SVM)为分类器,遗传算法(GA)为特征子集的搜索算法,构建了封装型的特征选择算法GA-SVM,并用ENVI/IDL语言编程实现,最后以HYPERION高光谱数据为例对算法予以应用。结果表明,GA-SVM算法可从196个波段中选择出13个波段,同时分类精度较不做特征选择时提高了约4%。由此可见,GA-SVM封装型特征选择算法具有较好的同时优化特征子集和SVM核函数的性能,可为当前高光谱数据的特征选择提供一个较好的算法。 相似文献
100.