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INTRODUCTION Oil and water well is an important basic estab- lishment in oilfields. In many oilfields, there are many different damages in the well’s casing walls after its development for a period of time. They will affect the normal production of damaged wells and adversely influence the neighbouring wells and the block, and threaten steady production. There are different kinds of damages due to multiple problems in the casing walls, for example, corrosion, perforation, decreased diame… 相似文献
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在气液两相流研究中,相分布、相速度等流场特征信息对深入了解流动机理、提高模型计算精度有重要意义,但由于气液流动的复杂性与随机性,使得它们的准确测量较为困难。该研究基于快速电阻层析成像技术,首先对垂直向上气液管流中弹状流流型下多种工况的流动结构进行图像数据采集与重建;然后通过互相关算法得到轴向速度场分布,并与漂移流模型进行对比;再对按时序排列的横截面图像序列进行调整得到正确比例的空间三维图像;最后获得段塞长度、频率等特征信息。结果表明,快速电阻层析成像技术可以测得速度场分布、段塞长度、频率等特征信息,可用于优化与这些参数相关的理论模型和经验关系式,有助于提高气液两相流的模型计算精度。 相似文献
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高考英语复习，要遵循英语学科的特点和学生的思维方式。科学的指导思想、有机的组织教学过程和合理地运用方式方法，对于提高复习效率具有举足轻重的意义。学会学习是素质教育的重要目标之一，也是顺应时代发展的需要。让学生会学是教师必须担负的责任。在高三英语教学中同样必须指导学生掌握正确的学习英语的方法，使复习教学更高效。要使学法指导有效进行，必须培养学生良好的学习习惯，教师应充分利用教材进行学法指导。 相似文献
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数控技术是20世纪后半叶最重要、发展最快的工业技术之一。本文讨论了用数控技术改造普通机床的意义和必要性,并以典型车床为例,提出了的整体改造方案,为机床的数控改造提供参考。 相似文献
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INTRODUCTION The imaging and measurement of multiphase flows has received much attention in recent years, largely because of a need in the oil industry to measure the mass flow rates of oil, water and gas in production pipelines, and the ability to see through objects and make quantitative measurements of the enclosed ma- terials and structures has wide range of applications. However, measurement over a wide range of flow regimes and the ability to very accurately measure the mass flow rat… 相似文献
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李志彪 《中学生英语读写(高中版)》2002,(5)
先看下面两道高考题:1.__to take this adventure course will certainly learn a lot of usefulskills.(NMET2000-8) A.Brave enough students B.Enough brave students C.Students brave enough D.Students enough brave2.If I had__,I’d visit Europe,stopping at all the small interestingplaces.(NMET’98—11) 相似文献
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INTRODUCTION Oil-water-gas multiphase mixed transport in oil pipe is extensively used in ocean oil industries. How to measure the volumetric fractions of oil-water-gas multiphase flow is an important subject of study in the oil industry. Related research work was started in the 1980s. The measurement of component ratios in multiphase flows using γ-ray attenuation was first suggested by Abouelwafa and Kendall (1980), and the technique has been used in many current com- mercial multiphase… 相似文献
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溢流阀是重要的压力控制阀.作者针对溢流阀教学中存在的问题,结合自己的工作实践,提出了适合的教学方法,进行了有益的探索. 相似文献
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机械制图是机械工程专业最重要的专业基础课程之一.作者针对机械制图教学中存在的问题,结合自身工作实践,提出了自己的方法,做出了有益探索. 相似文献
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当前课堂教学评价中数据的处理以算术平均数来判断分数的高低,缺乏科学性。本文作者结合工作实际,将数理统计和教育测量技术有机地结合,建立了一种计算评价结果的数学模型,并提出了详细的计算方法。结果表明,该计算模型使得课堂教学评价更具科学性、合理性、客观性。 相似文献