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1.
The NW‐SE trending Cantarell structure in the Gulf of Campeche hosts the largest oilfield in Mexico. The oil occurs predominantly in latest Cretaceous – earliest Tertiary breccias with subsidiary reserves in Upper Jurassic (Oxfordian and Kimmeridgian) and Lower Cretaceous oolitic and partially dolomitized limestones, dolomites and shaly limestones. Cantarell has been interpreted both as a fold‐and‐thrust zone and as a dextral transpressional structure. Analysis of structure contours at 100m intervals, on the tops of the Tertiary breccia and the Kimmeridgian (Upper Jurassic) dolomite, indicates that the structure is an upright cylindrical fold with gently plunging conical terminations; there is also a conical portion in the central part of the structure. The axes of the central, NW and SE cones are subvertical. This geometry indicates that the two fold terminations and the central cone are aprons rather than points, with the NW and central cone axes intersecting the cylindrical fold axis at the point where the geometry switches from conical to cylindrical. The apical angle (i.e. the angle between the fold and cone axes) varies as follows: (i) in the NW cone, it is ~70° in the breccia and ~76° in the Kimmeridgian dolomite; (ii) in the central cone, it is ~77° in the breccia and ~73° in the Kimmeridgian dolomite; and (iii) in the SE cone, it is ~64° in the breccia and ~57° in the Kimmeridgian dolomite. This indicates that whereas the fold opens with depth in the NW cone, it tightens with depth in the central and SE cones. Assuming a parallel fold geometry, these apical angles indicate an increase in volume in the NW cone (i.e. larger hydrocarbon reservoirs), compared to the central and SE cones. Theoretical considerations indicate that the curvature increases dramatically towards the point of the cone. In the case of the Cantarell structure, the apices of the cones are located at the conical‐cylindrical fold junctions, where the highest curvature may have resulted in a higher degree of fracturing. The coincidence of maximum curvature and the intersection of the conical and cylindrical fold axes in the fold culminations with porous and permeable reservoir rocks may have made these locations favourable for the accumulation of hydrocarbons. 相似文献
2.
用于X光激光实验的反射式线聚焦光学系统的设计和分析 总被引:1,自引:1,他引:0
基于三维光线追迹的象差计算,对卢瑟福实验室用离轴球面反射线聚焦系统作了分析。然后,首次提出了用于X光激光实验的两类新的反射式线聚焦构型,即反射式光楔列阵和光锥列阵系统,并作了计算。最后,对所得结果作了比较和讨论。 相似文献
3.
高精度视觉贴片机拾放程序设计编程 总被引:3,自引:0,他引:3
龙绪明 《电子工业专用设备》2002,31(3):151-155,183
探讨了SMT高精度视觉贴片机难点之一拾放程序设计编程 ,重点介绍示教编程和CAD输入编程设计方法。 相似文献
4.
本文对非线性锥形梯度折射率透镜进行了分析,根据稳态自聚焦理论以及ABCD定律,导出了高斯光束通过这种透镜光斑尺寸及其位置的公式。讨论了几种特殊的情况,得到了一些重要的结果。 相似文献
5.
Effects of circumferential pick spacing on boom type roadheader cutting head performance 总被引:4,自引:0,他引:4
E. Mustafa Eyyuboglu Naci Bolukbasi 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2005,20(5):418-425
Effects of equal and unequal circumferential pick spacing on the performance of boom type roadheaders having cylindrical cutting heads are investigated. For this purpose, two experimental cutting heads with equal and unequal circumferential spacing are designed and manufactured. The cutting head with unequal circumferential spacing is specifically designed to prevent tool-holder overlap at the nose section. Manufacturing difficulties associated with equal circumferential pick spacing due to tool-holder overlap are discussed with solid modeling and practical applications. The heads are tested at Park Cayirhan Coal Mine in Turkey and their cutting performances are analysed. Although better cutting performance for equal circumferential spacing are predicted by force–balance analysis, in situ measurements of instantaneous (net) traversing speed and cutting rate, pick consumption rate and machine vibration show that no significant difference exists between the performances of the two cutting heads. 相似文献
6.
7.
我们研制了一种8毫米波变张角、半径突变的多模圆锥馈源。计算出其模比并推导出其辐射方向图公式;给出其在两个主平面——E平面与H平面上的辐射方向图和波束场分布特性的测试结果以及电压驻波比VSWR的测量结果;同时给出频带和旁瓣特性。分析与测试共同表明,在34.5GHz~37GHz频带里,该多模馈源的辐射图在大于24dB范围内获得幅度等化且不出现旁瓣,因此具有一定的应用价值。 相似文献
8.
聚合物熔体在圆锥短口模的挤出胀大方程 总被引:3,自引:1,他引:3
深入讨论了聚合物熔体在不同长径比、不同角度圆锥短口模的挤出胀大现象及机理,利用生产用挤出机进行不同角度的圆锥短口模实验。结果表明,圆锥短口模挤出过程中,熔体在收敛流道受到拉伸流变,导致强烈的入口弹性效应,表现为熔体在短口模挤出时显著的挤出胀大。理论和实验研究结果进一步表明不同圆锥口模入口角对实验材料表现出有不同的挤出胀大值。 相似文献
9.
Experimental investigations have been carried out for spherical and non-spherical particles using beds comprised of single-sized particles and mixtures in the size and particle density ranges of 439 to 1524 μm and 1303 to 4948 kg/m3, respectively. Five conical fluidizers with varying apex angles of 8.86, 14.77, 19.60, 32.0 and 43.2 degrees were used. Experimental values of minimum velocity and bed pressure drop with air as the fluidizing medium have been compared with their respective values obtained from different models available in the literature. Deviations for each chosen model have been presented. 相似文献
10.
以工程实例为依据,论述国内以往较少采用的大型梁柱式支承锥顶贮罐的结构,介绍了国内外相关设计标准,给出了贮罐的典型结构-斜椽,横梁和立柱的计算公式,并用Excel电子表格编制了计算书。 相似文献