共查询到20条相似文献,搜索用时 78 毫秒
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低温绝热气瓶漏放气性能的研究 总被引:1,自引:0,他引:1
以低温绝热气瓶为研究对象,设计并搭建气瓶漏放气及残余气体分析实验台,开展了室温和低温下容器漏放气和残气分析的实验研究。通过理论分析与实验研究相结合得出:室温下,气瓶真空夹层内残余气体中H2的含量约为70%,可以利用复合材料扩散放气模型预测低温绝热气瓶的漏放气;低温下,气瓶真空夹层内残余气体中H2的平均含量达到81%,可以利用金属材料扩散放气模型预测低温绝热气瓶的漏放气。本文的研究有助于推动真空维持技术的应用,对于提高高真空多层绝热低温容器产品的寿命、降低成本和确保产品的可靠性,都具有十分积极的意义。 相似文献
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为了确保低温传输管线的设计质量,采用高真空多层绝热方式减少管线的漏热。通过分析多层绝热和支撑表面辐射,对低温传输管线进行了传热模拟研究,得到了内管道壁面间的辐射换热量和支撑总体漏热量。分析了三角形和正方形支撑漏热量的不同;同时对比了不同发射率支撑表面下,支撑辐射换热量、导热量和温度分布的变化。结果表明:在满足支撑强度条件下,应当增大热传导距离,减小支撑的接触面积以及辐射换热面积;随着支撑表面发射率增大,支撑表面辐射换热量增加,导热量减少,总体漏热量增大,当发射率为1时,模拟得到的漏热量仍小于1 W/m。 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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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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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
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由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。 相似文献
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M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
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V. T. Kornienko 《Strength of Materials》1991,23(7):760-765
The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991. 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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