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11.
ODP204航次天然气水合物的可能有利储层——浊积层   总被引:3,自引:1,他引:3  
为了解岩性在天然气水合物分布中的作用, 利用岩矿鉴定、扫描电镜和能谱法对ODP204航次的 4个站位 10个钻孔共计 115个沉积物样品进行分析, 发现沉积物中矿物成分基本相近, 以粘土矿物为主, 含少量以石英为主的陆源碎屑。样品中含有丰富的硅藻和有孔虫等微体化石, 可形成硅藻粘土—硅藻土、有孔虫硅藻土或凝灰质硅质生物粘土。石英碎屑大多呈棱角状, 粒径小、含量少, 同时, 样品中可见透镜体、团块或旋涡状层状结构以及杂乱堆积的斑杂构造。上述特征表明沉积物为含有大量深海或半深海的浊流沉积物或其夹层。由于钻井岩心中有相当部分的天然气水合物样品分布在上述沉积物中, 推断这些浊流沉积物很可能是ODP204航次天然气水合物的有利储层。  相似文献   
12.
生态工法评估指标的建立   总被引:1,自引:0,他引:1       下载免费PDF全文
李锦育 《水科学进展》2005,16(3):361-367
基于集水区的尺度下,利用几种相关指标,以生物性与非生物性作一区隔,并进一步与生态工法施工准则加以结合,建立了一评估的方法论,探讨了工法施工之成效性。建立长期的河川水质监测计划,以了解在施工前、中及施工后的水质变动情形,避免工程对河川生态环境造成破坏。生态工法在指标的选择上应包含不同尺度的考量,以河川流域管理之完整性为主,藉由多样化的评估指标,提供决策者在拟定计划时能参考运用;另一方面也需运用生物指标的监测,提供具生态考量之工程规划参数,使工程施工能兼顾生态环境。  相似文献   
13.
A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion  相似文献   
14.
1 INTRODUCTION Evolution of the river bed in alluvial channels has been studied by many researchers using analytical and numerical approaches. The use of analytical approach alone is insufficient for solving natural river engineering problems. With rapid growth in computer technology, numerical models have become a popular means for the study of mobile bed hydraulics. During the past decade, several numerical models have been developed. Most of the computer codes, such as HEC2SR (Si…  相似文献   
15.
New morphologic information permits systematic revision of trilobites from the Middle Ordovician Klimoli Formation of the Zhuozishan area, Ordos Basin, Inner Mongolia. The new assemblage is composed of 10 species of the Raphiophoridae, Nileidae, Asaphidae, and Telephinidae.? An asaphid, aff. Mioptychopyge lashachungensis (previously Paraptychopyge lashachungensis) displays an intermediate morphology between the Chinese nobiliasaphine genera Mioptychopyge and Zhenganites. The pygidial doublure is regarded as the most significant character to differentiate Symphysurus klimoliensis (previously Nileus klimoliensis) of the Nileidae from such closely allied taxa as Poronileus. A nileid, cf. Peraspis kujandensis displays typical nileid morphology, unlike the type species, Peraspis lineolata, which might turn out to be an asaphid. Ampyx gongwusuensis sp. nov. of the Raphiophoridae is the first record of the genus in the Zhuozishan area and reveals morphologic details that might be employed to resolve Ampyx taxonomy in China. Morphologic differences between A. gongwusuensis and Abulbaspis ordosensis might represent a case of sexual dimorphism.  相似文献   
16.
17.
Rare earth elements (REEs: La-Lu) in surface sediments collected from the mouth and middle tidal flats of Gomso Bay, South Korea, in August 2011 and May 2012 were analyzed to investigate the fine-grained sediment provenance. The upper continental crust (UCC)-normalized light REEs (LREEs: La to Nd) were more enriched than the middle REEs (MREEs: Sm to Dy) and heavy REEs (HREEs: Ho to Lu), resulting in large (La/Yb)UCC (1.9 ± 0.4) to (Gd/Yb)UCC (1.4 ± 0.2) ratios. The monthly (La/Yb)UCC values differed between the mouth and middle tidal flats due to deposition of fine-grained sediments that originated from distant rivers (the Geum and Yeongsan) and the Jujin Stream, located on the southern shore of the inner bay. We observed relative reductions in the (La/Yb)UCC value and REE content in the sediments from the mouth of the bay compared with those from Jujin Stream sediments. Confined to the middle tidal flat around the KH Line of Jujin Stream, the sediments, most enriched in LREEs but depleted in Eu, were distributed in August as strong Jujin Stream runs. Here, we suggest that an increase in LREE/HREE and decrease in MREE/LREE ratios can be used as a proxy to identify the Jujin Stream provenance in mixed riverine sediments and to trace Jujin Stream sediments within the Gomso Bay tidal flat, especially in the summer rainy season.  相似文献   
18.
海洋环境立体监测系统的设计方法   总被引:10,自引:1,他引:9  
“九五”和“十五”期间,在国家海洋863计划的支持下,我国分别在上海和台湾海峡及毗邻海域建立了两个区域性海洋环境立体监测示范系统。在这两个示范系统的技术研究成果的基础上,通过分析国际海洋立体监测系统的设计模型,提出了区域性海洋环境立体监测系统的设计原则和设计方法,包括:系统结构、数据与信息服务通信网络、数据处理中心、数据流程以及系统功能等方面的设计方法。  相似文献   
19.
碳酸酐酶CA(EC 4.2.1.1)是含锌原子的金属蛋白酶,该酶的基本功能是催化CO2与HCO3-间的相互转换[1].该反应在许多生物过程中都发挥着重要的作用,例如离子交换、呼吸作用、pH稳定性、捕获CO2和光合作用等[2~5].CA广泛分布于各种生物中,已知的CA酶根据氨基酸序列被分为-αCA,-βCA和γ-CA三种类型[5~7].这3种类型的CA酶序列间的相似性很低,被认为是由不同的途径进化而来的[7].α-型的CA酶在动物、植物、绿藻、细菌和蓝细菌中都有发现[7],在藻类中报道的α-型CA还很少.迄今为止只在衣藻中发现2种异构体,在盐藻中发现3种[8,9],在红藻中还未见报道.  相似文献   
20.
This study evaluates the uncertainty involved in the determination of the flash flood guidance(FFG) of the flash flood warning system(FFWS) for a small mountainous region(FFWS_MR)in Korea. The sensitivity is evaluated both at each step to determine the FFG and for all steps together. The results show that the relative difference of the FFG is about 50% of the current system, most of which involves the channel width. Especially, the use of some specific empirical equations to estimate the major parameters results in a considerable amount of the relative difference of the FFG. In addition, though only four basins were field-surveyed, it is found that the indirect estimation of the major parameters always introduces some amount of additional uncertainty. In conclusion, accurate estimation of the major parameters must be the most important procedure to derive an accurate FFG, among which the channel cross-section at the exit of the basin lies at the center.  相似文献   
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