Experimental study on mechanical properties of gas hydrate-bearing sediments using kaolin clay     

李洋辉  宋永臣  于锋  刘卫国  赵佳飞 《中国海洋工程》2011,25(1):113-122

A triaxial system is designed with a temperature range from-20 ℃ to 25 ℃ and a pressure range from 0 MPa to 30 MPa in order to improve the understanding of the mechanical properties of gas hydrate-bearing sediments.The mechanical properties of synthetic gas hydrate-bearing sediments (gas hydrate-kaolin clay mixture) were measured by using current experimental apparatus.The results indicate that:(1) the failure strength of gas hydrate-bearing sediments strongly depends on the temperature.The sediment’s strength increases with the decreases of temperature.(2) The maximum deviator stress increases linearly with the confining pressure at a low-pressure stage.However,it fluctuates at a high-pressure stage.(3) Maximum deviator stress increases with increasing strain rate,whereas the strain-stress curve has no tremendous change until the axial strain reaches approximately 0.5%.(4) The internal friction angles of gas hydrate-bearing sediments are not sensitive to kaolin volume ratio.The cohesion shows a high kaolin volume ratio dependency.  相似文献   

关于定量监测悬浮泥沙浓度方法的回顾和展望     

匡良  于华明  丁扬  李希彬  匡华 《海洋通报(英文版)》2011,13(2):51-61

获取近岸水体中悬浮物浓度及相关信息对于理解和管理海洋环境相当重要。历史上对于悬浮物浓度的监测往往通过费时费力的出海观测,而这种观测具有很大的局限性,每次观测只能获取一个站位的信息。为了更快更有效的获得即时悬浮物浓度相关信息,很多新的监测手段及相关科技被开发及应用。各种机载,卫星载遥感设各被用于获得及时,全面的沉积物信息...  相似文献   

海岸带区域SPOT卫星数据大气校正处理     

王小飞  毛志华  陈建裕 《海洋学研究》2011,29(1):68-72

将SPOT卫星自身近红外波段的数据作为气溶胶信息的来源,假设近红外波段暗像元受到大气影响较弱,卫星表观反射率近似等于地表反射率,且近红外波段暗像元与红光波段具备近似的线性关系,通过开源6S大气辐射传输模型的调试运行,并结合敏感性实验建立大气校正所需的查找表,最后通过一定的算法,实现了SPOT卫星Level_0级数据的大...  相似文献   

渤中凹陷A2—1构造东营组储层物性控制因素分析     

朱文森  王清斌  刘士磊  宋章强  王雪莲  陈延芳 《海洋地质译丛》2011,(4):59-62

根据岩石薄片、扫描电镜、物性和测井等资料,分析了渤中凹陷A2—1构造东营组砂岩储层品质控制因素,探讨了测试段产能差异的原因。通过分析认为：渤中凹陷古近系东营组储层物性主要受压实作用、沉积条件、碳酸盐胶结、溶蚀作用和黏土转化阶段控制。在负胶结物投点图上,犬部分砂岩都落在压实作用区间,显示了压实作用是减少孔隙的主要因素;沉积条件对储层物性的影响突出体现在粒度和泥质含量方面的影响,随着粒度变细、泥质含量增加,渗透率明显降低。储层中普遍含碳酸盐胶结物且含量较高,是DST2测试段渗透率低、产能差的重要原因之一。两测试段储层中溶蚀作用普遍存在,主要体现在对长石的溶蚀,DST2测试段是强超压的半封闭系统,溶出物不能有效带出系统而沉淀在孔隙和喉道中,对储层物性破坏较大。黏土转化阶段与渗透率的快速降低段有较好的对应关系,渗透率变差段主要出现在伊蒙混层有序混层带以下。  相似文献   

吲哚乙酸对微拟球藻生长和脂肪酸含量的影响     

焦媛媛  俞建中  潘克厚 《中国海洋大学学报(自然科学版)》2011,41(4):57-60

研究不同浓度吲哚乙酸(Indole-3-Acetic Acid,IAA)对微拟球藻(Nannochloropsis oculata)生长和脂肪酸组成的影响。结果表明:在0.1 mg/L时,低于0.5 mg/L时IAA促进微拟球藻生长,但不影响叶绿素和不饱和脂肪酸合成;IAA促进生长作用最显著,最大比生长率为2.33 d-1。随浓度进一步增加,IAA促生长作用越来越小,并抑制叶绿素和不饱和脂肪酸合成;在5 mg/L时,IAA极显著抑制EPA合成。添加适当浓度IAA可促进藻细胞生长,缩短其生长周期。  相似文献   

三种金银矿物的初步研究及其意义     

孙启松 《湖南地质》1994,13(4):201-204

湘西某金矿区发现的三种金银矿物，其化学成分分别为金银汞互化物和银汞互化物。本文就其镜下特征、产出形态、共生矿物、成因等作一简要介绍，期望引起关注，促进深入研究。  相似文献   

冰云光学特性与等效球Mie理论的误差分析     

张国栋 《成都信息工程学院学报》1997,(4)

用改进的射线光学理论和等效球Ｍｉｅ理论，计算了若干冰晶和冰晶尺度分布在太阳光谱区中一系列波长上的光学特性和散射特性，详细分析了Ｍｉｅ散射计算的误差，并假定冰云光学特性有１０％误差的情况下，用Ｄｅｌｔａ－Ｅｄｄｉｎｇｔｏｎ近似对所引起的冰云辐射特性的误差进行了数值试验。结果表明，沿用已久的等效球Ｍｉｅ理论因计算冰云光学特性在波长小于２．６μｍ波段误差过大，将引起冰云辐射特性有显著误差，最后提出了计算冰云光学特性的新方案。  相似文献   

Terraced fills of Pleistocene and Holocene age in the Rheidol Valley,Wales     

Mark G. Macklin  John Lewin 《第四纪科学杂志》1986,1(1):21-34

The legacy of repeated Pleistocene glaciations has endowed many Welsh river valleys with locally thick successions of glacial and alluvial sediments. Investigations of a well-preserved flight of terraced sediments with good exposures at Capel Bangor, on the Afon Rheidol, mid-Wales, has allowed its Quaternary valley fill stratigraphy to be examined in detail. Study has revealed five terraced fills consisting of seven distinct sedimentary units. These range from Late Devensian ice-contact and ice-marginal deposits, to Holocene high-sinuosity stream sediments with episodes of man-induced accelerated deposition of fine-grained alluvium, and to aggradation and subsequent incision associated with historic metal mining. Examination of general sedimentary properties (e.g., granulometry, sedimentary structures, terrace surface morphology) show both differences in the pattern and controls of deposition and also progressive changes over Late Devensian and Holocene times. The sediments of the Rheidol Valley record the response and subsequent recovery of a drainage basin to glaciation, and the increasing influence of man on sediment yields, channel processes, and sediment quality.  相似文献   

Optical positions of 3C 273     

Wang Shu-he  Xu Tong-qi  Lu Pei-zhen 《Chinese Astronomy and Astrophysics》1990,14(4):449-453

We have measured an optical position of 3C 273 in the AGK3 system using the 40cm astrograph of Shanghai Observatory. Combining with others' observations, we have derived a “proper motion”. A comparison with other results is made.  相似文献   

An easy-to-use Model for the Optical Thickness and Ambient Illumination within Cometary Dust Comae     

Müller  Michael  Green  Simon F.  McBride  Neil 《Earth, Moon, and Planets》2002,90(1-4):99-108

We define a procedure which allows estimation of the optical thickness of a cometarydust coma and the ambient illumination of the nucleus for any given comet, if estimatesof the nucleus radius and the dust activity (Afρ) are available. The calculation isperformed for a singly scattering coma with a cos(ϑ) distribution of dust overits day side. We find that the ambient illumination is of the same order as the incidentsunlight if the optical thickness is of order one. The optical thickness increases, all elseequal, linearly with the nucleus radius. Therefore the effect of the presence of the comamay be neglected for small (≈ 1 km diameter) comets, but is important forcomets such as 1P/Halley and Hale–Bopp.  相似文献