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通过对连云港碱厂厂外埋地钢质输水管网沿线土壤、水质的测量与分析,确定了埋地管网周围环境的腐蚀性,分析了埋地钢管的腐蚀原因,采用阴极保护抑制了埋地管线的腐蚀泄漏趋势。 相似文献
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随着气田建设规模的扩大,集、输气管线逐渐增多,如何选择埋地管道的外防腐方式是气田设计者面临的主要问题,本文详细地分析了庆深气田埋地管线腐蚀类型,介绍了国内外埋地钢质管道外防腐层的种类及其在管道中的应用情况,分析评价了不同的内防腐方式的技术经济状况,为庆深气田管道防腐的选择做出了有益的探索与建议。 相似文献
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为探明硐室爆破中的盲炮,在瞬变电磁法的基础上进行改进形成瞬态电磁耦合法,进行盲炮检测与识别的可行性理论分析与实验论证。在硐室内预置电磁灵敏感应器,在地表布置瞬态电磁耦合检测系统,检测炸药爆炸前后电磁场异常状况来实现硐室爆破盲炮检测与识别。结果表明,电磁灵敏感应器在感应耦合的作用下产生规则化涡流,在复杂的地形地质条件下,可以检测与识别出埋深不超过55m的单个盲炮;药室内的电雷管可能产生的感应电流远小于安全电流,可确保检测过程中电雷管的安全;但对于存在多个盲炮瞬态电磁耦合法难以精确的检测与识别。 相似文献
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由于土石坝结构的复杂性及其自身的特点,决定在探测技术上的困难很大。在现有的地球物理勘探方法当中,对于土石坝隐患的探测方法有很多,高密度电阻率法、探地雷达法等等都是较为成熟使用的隐患探测技术。鉴于在介绍土石坝自身特性后,采用瞬变电磁的方法通过对隐患模型进行实验研究分析,以便为在现场利用瞬变电磁法探测土石坝隐患奠定基础。 相似文献
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《中国新技术新产品》2020,(13)
由于城市进程快速推进,管道施工不规范,导致许多埋地燃气管道存在不可见的安全隐患,因此对城镇燃气管道的外防腐层检验检测工作势在必行。为了对管道安全进行检测及评估,避免隐患留存,该文主要以云南省昆明市埋地钢质管道防腐层现场检测项目为研究案例,分别从检测原理、整体防腐层检测及开挖破损点状况展开探究,具体采用"ACVG法"和电流衰减法对外腐蚀直接检验,并运用相关软件对检测数据进行处理,对管道整体质量状况进行评价及风险预警,保障管道安全稳定运行。 相似文献
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《中国新技术新产品》2015,(15)
本文首先简要分析了埋地钢质燃气管道的腐蚀机理,在此基础上提出埋地钢质燃气管道牺牲阳极阴极保护的设计思路。期望通过本文的研究能够对埋地钢质燃气管道使用寿命的延长有所帮助。 相似文献
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A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
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An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
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水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献
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Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献