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191.
192.
The Occurrence of Oleananes in the Beibuwan Basin and Its Application to the Study of Maturity and Oil-Source Rock Correlation 总被引:3,自引:0,他引:3
LI Meijun WANG Tieguan State Key Laboratory of Petroleum Resource Prospecting Earth Sciences Geoinformatics School China University of Petroleum Beijing China LIU Ju ZHANG Meizhu MA Qinglin GAO Lihui Southern Oil Exploration Development Company PetroChina Guangzhou China LU Hong Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China 《《地质学报》英文版》2008,82(3):585-595
The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance (Ro/%), the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins. 相似文献
193.
作者认为,一切与灾害有关的地质问题,都是地质环境诸因素综合作用的结果。通过对环境因素作用机理和机制分析,可以解释一切地质灾害问题,可以剖析灾害性地质现象的孕育和激发过程。通过调整和改善地质环境中的某些环境因素,可以减轻或消除某些地质灾害,从而为工程建设的稳定和人类生活安全提供保障。众多学者在寻求新的能够科学地反映地质灾害规律的理论,而作者提出了环境因素控制论。 相似文献
194.
The objective of this research was to assess the characteristics of seismic induced damage and the deformation patterns of pre-stressed cement-grouted cables that are used for rock slope stabilization projects subjected to quasi-static cyclic loading. The experimental configuration includes the installation of 15 pre-stressed cables in a slope model made of concrete blocks (theoretically rigid rock mass) on top of a pre-existing sliding surface. The study showed that: (i) The pre-stressed cables exhibited great seismic performance. Rapid displacement of the model blocks was observed after the complete loss of the initial pre-stress load under continued applied cyclic loads and exceedance of the state of equilibrium, which implies the higher the initial pre-stress load, the better the seismic performance of the rock anchor; (ii) The failure of the pre-stressed cables was due to fracture at the connection of the tendons and cable heads under cyclic loading. The sequence of failure had a distinct pattern. Failure was first observed at the upper row of cables, which experienced the most severe damage, including the ejection of cable heads. No evidence of de-bonding was observed during the cyclic loading; (iii) The stress distribution of the bond length for pre-stressed cables was highly non-uniform. High stress concentrations were observed at both the fixed end and the free end of the bond length both before and immediately after the state of equilibrium is exceeded. The results obtained can be used to evaluate the overall performance of pre-stressed rock anchors subject to seismic loading and their potential as rockfall prevention and stabilization measures. 相似文献
195.
选取长江流域沿线及三峡库区12个代表站,根据中国500年旱涝图集等级和各站建站以来5—9月降水量资料,按照旱涝等级标准,分别得到长江全流域、上游流域、中游流域、下游流域及其三峡库区1470—2011年旱涝等级序列。结果表明:长江各流域及其三峡库区均呈现较为明显的旱涝交替阶段,20世纪偏旱频率强烈增加,19世纪和20世纪偏涝频率明显增加。长江流域和三峡库区偏旱以上等级具有准160年周期震荡,全流域偏涝以上存在准140年的周期震荡,但20世纪后有所减弱,三峡库区偏涝以上等级存在准百年的周期震荡。三峡建坝蓄水前后库区降水EOF时空分布呈一致减少趋势,与此同时长江上游降水呈下降趋势,反映了长江上游流域及三峡库区气候趋旱;M-K突变检验显示水库蓄水前后流域上游和库区降水均未发生显著变化。在全球气候变化的背景下,三峡库区旱涝演变并不是孤立事件,而是与长江上游乃至整个长江流域旱涝背景密不可分。 相似文献
196.
197.
采用结合匹配法和经验正交函数法的射线声层析反演方法,针对流场水平分布不均匀特点,使用距离等效分段方法对反演算法进行改进,利用三个断面声层析数据,对胶州湾口潮流场的垂直和水平分布进行反演。与传统方法比较,大大降低与实测流速垂直分布间的偏差,平均偏差小于0.02 m/s,流场垂直分布间的相关系数提高到0.85以上。分析了声传播断面上不同的流场结构,以及涨潮期间在胶州湾团岛附近出现的涡流现象,并计算得到湾口海水流量变化。结果表明,改进的射线声层析反演方法可有效地用于水平分布不均匀流场监测,仅采用少量声学观测站位,即可获得大范围的复杂流场三维信息,有利于近海海洋资源开发、海洋环境保护和船舶航行安全。 相似文献
198.
An index of relative importance (IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling (NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only Amblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types: (1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others; (2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and (3) narrow niche breadth species, including Atrobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Differences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships affected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution differences compared with other species. 相似文献
199.
P. A. Stunzhas P. Ya. Tishchenko V. V. Ivin Yu. A. Barabanshchikov T. I. Volkova D. I. Vyshkvartsev V. I. Zvalinskii T. A. Mikhailik P. Ju. Semkin P. P. Tishchenko N. D. Khodorenko M. G. Shvetsova F. M. Golovchenko 《Doklady Earth Sciences》2016,467(1):295-298
In August 2013, anoxia of the bottom waters was established in the southern region of the Far East Marine Biosphere Reserve, Far East Branch, Russian Academy of Science, in the depression between Furugelm Island and coastal waters. Death of the benthic community was registered using a remotely operated underwater vehicle. The hydrochemical studies revealed that the area of the absence and/or presence of low oxygen contents corresponds to an area of anomalously high contents of ammonium, phosphates, and silicates, a high partial pressure of carbon dioxide and normalized alkalinity, and the presence of hydrogen sulfide. The microbiological decomposition of diatoms precipitated on the seafloor in the absence of oxygen regeneration was the reason for anoxia. Its formation in summer of 2013 was caused by anomalously abundant precipitates in the Far East. 相似文献
200.
随着卫星遥感获取技术的发展,运用遥感技术获取的影像资源日益丰富,特别是高分辨率遥感影像被列入国家重大工程建设以来,其在制作正射影像、三维模型、对地观测系统等方面作用突出,能够真实地反映研究地区地表的各种地理信息特点。与此同时,高分辨率遥感影像能够在实时状态下获取地理信息,可满足未来信息化战争、非战争军事行动等对地理环境保障提出的新要求。本文结合工作实际,对高分辨率遥感影像制作方法,以及影像制作中方案的改进进行探讨,取得了事半功倍的效果。 相似文献