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131.
利用X射线衍射等分析方法,对贵州威宁麻窝山岩溶盆地沉积物中粘土矿物进行研究,获得了粘土矿物的组成、相对含量、结晶度指数、化学指数以及相对含量比值等方面的信息,探讨该盆地的沉积环境演化特征。研究表明,粘土矿物以伊/蒙混层矿物(30%~75%)和绿泥石(10%~45%)为主,高岭石(5%~20%)和伊利石(10%)次之,基本不含蒙脱石。伊/蒙混层矿物和绿泥石含量呈负相关性。高岭石含量在剖面底部较稳定,在484cm上部出现较大的波动。伊利石结晶度和化学指数与伊/蒙混层矿物含量具有较好的正相关性,且在第Ⅰ阶段相对于其它指标较敏感,出现波动。通过综合对比分析,将研究区剖面划分为4个阶段,其是3个冷暖干湿的大循环和若干个小循环气候环境的物质记录。  相似文献   
132.
本文利用石岛湾海洋站实测的连续20年的波高和风暴潮增水的数据资料,计算取得异常水位资料,以二元Gumbel-Logsitic分布模型为基础,考虑波高和增水的相关性,运用联合概率法,推算石岛地区多年一遇设计异常水位组合,并与均取极值方法的结果作对比。结果显示,石岛地区应采用以波高为主的同时性资料为主要分析资料,本文的方法更加接近实际情况,使用方便,结果可靠。  相似文献   
133.
This paper presents numerical simulations of viscous flow past a submarine model in steady turn by solving the Reynolds-Averaged Navier?Stokes Equations (RANSE) for incompressible, steady flows. The rotating coordinate system was adopted to deal with the rotation problem. The Coriolis force and centrifugal force due to the computation in a body-fixed rotating frame of reference were treated explicitly and added to momentum equations as source terms. Furthermore, velocities of entrances were coded to give the correct magnitude and direction needed. Two turbulence closure models (TCMs), the RNG model with wall functions and curvature correction and the Shear Stress Transport (SST) model without the use of wall functions, but with curvature correction and low-Re correction were introduced, respectively. Take DARPA SUBOFF model as the test case, a series of drift angle varying between 0° and 16° at a Reynolds number of 6.53×106 undergoing rotating arm test simulations were conducted. The computed forces and moment as a function of drift angle during the steady turn are mostly in close agreement with available experimental data. Though the difference between the pressure coefficients around the hull form was observed, they always show the same trend. It was demonstrated that using sufficiently fine grids and advanced turbulence models will lead to accurate prediction of the flow field as well as the forces and moments on the hull.  相似文献   
134.
基于恐龙足迹重建攀西地区白垩纪恐龙动物群   总被引:2,自引:2,他引:0  
攀西地区没有白垩纪恐龙骨骼化石记录,对该区白垩纪恐龙动物群组合的认识尚属空白。1991年,攀西地区首次发现了恐龙足迹,此后陆续发现了8个足迹点。这些足迹点共发现9种不同的非鸟恐龙足迹(6种非鸟兽脚类、1种蜥脚类和2种鸟脚类足迹),以及翼龙和龟类足迹。共11种足迹形态类型由185道行迹(与孤立足迹)组成,可能代表着同等数量的造迹者。其中飞天山组的组合多样性最强,小坝组和雷打树组较弱。这个相对全面的足迹数据库,为该地区白垩纪四足类的古生态学普查提供了动物群的组成信息,这在该缺乏骨骼化石的地区显得尤为重要。  相似文献   
135.
陈严飞  张娟  张宏  李昕  周晶  曹静 《海洋工程》2016,(2):231-241
Based on Hencky’s total strain theory of plasticity, ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material, the simplified analytical solution is proposed as well. Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes. Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes. It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material. Thus, the ignorance of strain hardening effect, as commonly assumed in current codes, may underestimate the ultimate bending capacity of steel pipes. The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes, supports of offshore platforms and other tubular structural steel members.  相似文献   
136.
正Objective During the Permian,at least four mafic continental large igneous provinces(LIPs)were formed in eastern Asia,i.e.,the Siberian traps(~251 Ma),Emeishan LIP(~260 Ma),Tarim LIP(~290–270 Ma)and Panjal traps(~290 Ma)(Shellnutt et al.,2015).The Emeishan and Tarim LIPs in China are both known for the presence of several magmatic Fe-Ti-V oxide deposits hosted in layered maficultramafic intrusions.The origin of such magmatic Fe-Ti-  相似文献   
137.
正Objective The Tibetan Plateau is the largest continent-to-continent collision belt in the world.Two orogenic gold mineralisation belts have been recognized in this collision belt,which are as follows:the Indus-Yarlung Zangbo suture zone orogenic gold belt(IYOG),represented by the Mayoumu and Bangbu gold deposits,and the Ailaoshan  相似文献   
138.
To understand the influence of the diagenetic water medium on the isotopic compositions of thermogenic coalbed gas, both hydrous and anhydrous closed-system pyrolyses were performed at temperatures of 250°C to 650°C on an herbaceous marsh peat. Compared to the results of anhydrous pyrolysis, the hydrocarbon gases generated from hydrous pyrolyses have very different hydrogen isotopic compositions. However, the carbon isotopic compositions of the hydrocarbon gases became only slightly heavier in hydrous pyrolysis, compared to that from anhydrous pyrolysis. With the progress of thermal evolution from peat to a more advanced thermal maturity of vitrinite reflectance values (Ro) of 5.5% during the pyrolysis, the difference in the average δD value increased from 52‰ to 64‰ between the hydrous pyrolysis with saltwater and anhydrous pyrolysis and increased from 18‰ to 29‰ between the hydrous pyrolysis with freshwater and anhydrous pyrolysis, respectively. The difference in the average δ13C value was only 1‰–2‰ between the hydrous and anhydrous pyrolysis. The relationships between the δD values of the generated hydrocarbon gases and Ro values as well as among δD values of the hydrocarbon gas species are established. The close relationships among these parameters suggest that the water medium had a significant effect on the hydrogen isotopic composition and a minimal effect on the carbon isotopic composition of the hydrocarbon gases. The results of these pyrolyses may provide information for the understanding of the genesis of coalbed gas from herbaceous marsh material with the participation of different diagenetic water media.  相似文献   
139.
受界面效应影响,毛细水在层状土中运移规律还难以用描述均质土中水分运移规律的Lucas-Washburn(LW)渗吸模型进行描述。基于此,本文设计了层状土室内模型试验,采用分布式的主动加热光纤法(简称AHFO)监测毛细水上升过程。根据AHFO测试结果,进一步对LW模型进行了修正,提出了适用于描述层状土中毛细水上升规律的ILW模型,并对ILW模型进行了试验验证。试验结果表明:(1)当毛细水湿润锋抵达“黏土(下部)-砂土(上部)”界面时,会产生“毛细屏障作用”,从而导致上部砂土中毛细水含水率急剧下降;(2)“毛细屏障作用”由砂土和黏土中的基质吸力不均衡造成,基质吸力大小由含水率决定;(3)当毛细水湿润锋抵达“砂土(下部)-黏土(上部)”界面时,在界面处出现“反毛细屏障作用”,从而导致上部黏土层中的含水率比相邻下部砂土层含水率更高;(4)虽然常见的LW模型可准确预测均质土中毛细水上升高度及速率,但受“毛细屏障作用”和“反毛细屏障作用”影响,LW模型在层状土中失效;(5)相比LW模型,ILW模型精度更高,能够更加准确地描述层状土中毛细水上升规律。  相似文献   
140.
松科二井2013年正式启动,2018年5月完井,历时6年,最终井深7018 m。项目执行过程中,形成合同700多个、文件200多个、汇款流水1000多笔、报账流水1600多笔。针对松科二井合同、文件繁多,财务流程繁杂,涉及项目多的特点,基于LabVIEW平台设计了一套项目管理系统。该系统可全程记录松科二井上述合同、文件、汇款和报账信息,建立合同及对应批次汇款和报销的勾稽关系,具有模糊查询、修改、超链接等功能。  相似文献   
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