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51.
南海流花碳酸盐岩台地近年来利用高精度3D地震资料处理解释技术,新发现珠江组礁灰岩地层发育数量众多的灰岩坑,平面上沿NWW向断层分布。由于灰岩坑的形成导致该区储层非均质性增强,油气成藏更加复杂,给油气勘探带来诸多困难和挑战。以岩心抽提物GC、GC/MS分析为基础,结合区域构造运动史、地层水动力特征等,分析该区埋藏酸性流体的成因与来源;并对"白垩状"灰岩成因提出新的认识,探讨了研究区埋藏酸性流体溶蚀模式。研究认为,埋藏酸性流体主要来源于:(1)烃源岩内有机质热演化作用及其生成的烃类与矿物和水的有机无机氧化作用,(2)原油运移过程中在输导层内的有机无机氧化作用,(3)油藏内原油的生物降解作用等形成的有机酸性流体。研究表明原油生物降解成因有机酸浓度可达4 300μg/g油以上。流花碳酸盐岩台地上发育的"白垩状"结构灰岩,是在活跃地层水动力条件下,由有机酸性流体长期溶蚀、浸泡和淘洗形成。在含油层段内发育的致密夹层,仅外部受酸性流体溶蚀改造而内部未受影响部分仍保留致密结构而未能形成"白垩状"灰岩。埋藏可溶性有机酸性流体在活跃的地层水动力条件下,通过复杂的裂缝网络发生运移,在断层和裂缝最发育区岩体破碎,酸-岩反应空间最大,速率最高,造成碳酸盐岩地层溶蚀垮塌,从而形成沿NWW向断裂体系分布的灰岩坑。  相似文献   
52.
以流花地区珠江组碳酸盐岩储集层抽提物GC、GC/MS分析为基础,结合区域构造运动史、地层水动力特征等,分析了该区埋藏酸性流体的成因与来源,探讨了"白垩状"灰岩的形成以及该区的埋藏酸性流体溶蚀模式。研究认为,埋藏酸性流体主要来自惠州凹陷文昌组烃源岩热演化成因有机酸,原油生物降解成因有机酸,岩浆活动生成的CO2等酸性流体。"白垩状"灰岩是在活跃油田底水环境下,主要由有机酸性流体长期溶蚀、浸泡和淘洗作用的结果。埋藏酸性流体以东沙构造运动形成的深大断裂及伴生的复杂裂缝网络为运移通道和物质交换空间,在流花低势汇流的强水动力条件下,与碳酸盐岩发生强烈的酸—岩反应,造成地层溶蚀垮塌,形成了现今流花地区灰岩坑的分布面貌。研究还排除了该区灰岩坑大气淡水溶蚀作用和白云岩化溶蚀作用成因的可能性。  相似文献   
53.
In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states (such as the European Union), but also those in- ter-governmental organizations (IGOs), international non-governmental organizations (INGOs) and diplomatic representatives and delegations that today also manage and regulate relations between and among states.  相似文献   
54.
�Ͷ�����ǰ���ʵ��Ա仯����   总被引:1,自引:0,他引:1  
???ü???????2013??12?°??Ms5.1???????????????????????????????????????о??????????о?300 km??Χ???????????·??????????????仯??????????????2012??????????????????????????????·??????????????????????????????????·????????????????????????????????  相似文献   
55.
Acidic polysaccharide, which has various biological activities, is one of the most important components of sea cucumber. In the present study, crude polysaccharide was extracted from four species of sea cucumber from three different geographical zones, Pearsonothuria graeffei (Pg) from Indo-Pacific, Holothuria vagabunda (Hv) from Norwegian Coast, Stichopus tremulu (St) from Western Indian Ocean, and Isostichopus badionotu (Ib) from Western Atlantic. The polysaccharide extract was separated and purified with a cellulose DEAE anion-exchange column to obtain corresponding sea cucumber fucans (SC-Fucs). The chemical property of these SC-Fucs, including molecular weight, monosaccharide composition and sulfate content, was determined. Their structure was compared simply with fourier infrared spectrum analyzer and identified with high temperature 1H nuclear magnetic resonance spectrum analyzer (NMR) and room temperature 13C NMR. The results indicated that Fuc-Pg obtained from the torrid zone mainly contained 2,4-O-disulfated and non-sulfated fucose residue, whereas Fuc-Ib from the temperate zone contained non-, 2-O- and 2,4-O-disulfated fucose residue; Fuc-St from the frigid zone and Fuc-Hv from the torrid zone contained mainly non-sulfated fucose residue. The proton of SC-Fucs was better resolved via high temperature 1H NMR than via room temperature 1H NMR. The fingerprint of sea cucumber in different sea regions was established based on the index of anomer hydrogen signal in SC-Fucs. Further work will help to understand whether there exists a close relationship between the geographical area of sea cucumber and the sulfation pattern of SC-Fucs.  相似文献   
56.
分析了单纯用地震波振幅作为报警阈值的缺点,通过数字地震仪与模拟地震仪报警机制的对比,提出用检测周期和振幅相结合的方法来实现地震报警。  相似文献   
57.
采用从1988-1999年的现代技术测定的高精度极移序列EOP(IERS97C04)推导出激发函数χ^m)和美国国家环境预测中心和美国国家大气研究中心(CNEP/NCAR)提供的大气角动量激发函数χp和χib^p,使用几种数据分析方法,分析了大气对极移高频振荡(12-42cpy)激发贡献,复数小波变换和功率谱分析表明,χ^m和χ^p序列在高频段内呈现比较强的谱峰,它们具有相似的谱特征,比较而言,χib^p在这个频率段内比χ^p要弱些,χ^m和χ^p之间的相关系数分别为0.75(逆向)和0.6(顺向),两个序列之间的平方相关谱的估计值分别在0.5-0.9之间(负频)和0.4-0.6(正频),相位谱表明χ^p(AAM)超前x^m一天左右,这些大气是极移高频变化的主要激发源,特别是在逆向运动上具有更大的贡献,由于它们之间位相差和振幅变化的不稳定性,说明可能存在AAM以外的其他激发源,这个问题有待进一步深入研究。χ  相似文献   
58.
59.
罗优  简鸿福  罗琳  邓亮  周念 《水科学进展》2018,29(3):348-356
多沙河流河口输沙不平衡带来的淤积演变过程,动态调整着上游河道控制基面,影响通航和防洪安全等。开展水槽试验,控制上游水沙条件和下游水位不变,研究河口三角洲自生性过程的形成机理、波动性和趋势性演变特征。试验中观测到淤积朵体迁移、溯源冲淤和河道摆动等自生性调整现象,其中朵体发育和迁移起控制作用。研究结果表明:自生性过程具有内在临界性,不同水沙条件下淤积朵体临界尺度不同,相应的水位波动周期、溯源波能量、水位涨落规律和三角洲形态亦有所差异。结合试验成果探讨了自生性过程形成的内在动力、临界性及其与三角洲形态的内在联系。  相似文献   
60.
Studies on the characteristics of relative humidity annual cycle change include the frequency, phase, and amplitude of the time series and their changes. The effective diagnosis of the relative humidity annual cycle can provide important help in the monitoring and regulation of seasonal haze, the spatial distribution of epidemic outbreaks and their prevention and control, and the real-time forecasting and decision-making of monsoon precipitation. Different from studies on the trend of the relative humidity, the diagnosis in the annual cycle is scarce. This paper summarized the research status of relative humidity and its annual cycle, introduced several current methods for extracting common signals, and evaluated the feasibility of these methods for extracting annual cycle signals. Due to the time-varying characteristics of the annual cycle of relative humidity and complex structures such as asymmetric triangular waves, square-like waves, and state transients, harmonic-based extraction methods are difficult to succeed. The nonlinear signal extraction method with high noise immunity will solve this problem. At present, the relative humidity annual cycle studies urgently need to be improved and improve the quality of relative humidity observation data, accurately extract and quantify the time-varying characteristics and complex structure of the annual cycle. Moreover, combining the dynamic process and statistical analysis, we also need to study the physical mechanism of the change of relative humidity annual cycle (frequency, phase, amplitude, etc.) in China.  相似文献   
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