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冰柜门玻璃用低辐射薄膜的防结露性能的理论和实验研究 总被引:1,自引:0,他引:1
通过模拟二个无限大平行平面之间的热交换方式,深入研究了可视冰柜单层门玻璃内外表面之间的热交换过程。分析了低辐射薄膜防止可视冰柜门玻璃表面结露的性能并进行了实验研究。提出了低辐射薄膜的置向原则和其发射率的适宜取值范围。 相似文献
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通过实地测试,在三个不同通风发热工况下,分析了某抽水蓄能电站交通进风洞对进入空气的热湿处理能力状况,重点叙述了交通进风洞的全热交换量和除湿量,以及洞深的不同对其热湿处理能力的影响,同时简单分析了实测过程中存在的冷热平衡问题及结露问题. 相似文献
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通过模拟二个无限大平行平面之间的热交换方式 ,深入研究了可视冰柜单层门玻璃内外表面之间的热交换过程。分析了低辐射薄膜防止可视冰柜门玻璃表面结露的性能并进行了实验研究。提出了低辐射薄膜的置向原则和其发射率的适宜取值范围。 相似文献
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水电站地下厂房的通风空调系统对维持厂房内的热湿环境,使其满足人员工作及设备运行的要求有着重要作用。为了对某抽水蓄能电站地下厂房的热湿环境进行评估,对主厂房各层空间空气的热湿参数及通风量进行测试,并结合室外天气状况得出室外天气对厂房内的热湿环境的影响。在测试过程中发现,其蜗壳层设备及管路表面结露问题严重。根据对结露现象的分析,提出相应的解决方案,为水电站地下厂房的热湿环境的调控提供参考。 相似文献
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钱贤青 《中国新技术新产品》2019,(10)
悬索桥能够充分利用材料的强度,用料省、自重轻,跨越能力最大。近些年来,悬索桥在大跨径桥梁建设中取得快速发展。某钢桁架悬索桥技术状况较差,承载能力不满足规范要求,需对原桥进行拆除。该文通过有限元分析模拟悬索桥不同拆除工况,根据不同工况计算结果确定悬索桥实际拆除方案,保证拆除过程中结构整体稳定性及安全性,并明确悬索桥实际拆除方案中具体施工流程及施工要点,为类似工程提供参考。 相似文献
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子模型法在超大跨悬索桥钢箱梁应力分析中的应用 总被引:5,自引:0,他引:5
以国内第一大跨桥梁——润扬长江公路大桥南汊悬索桥为背景,在对大桥整体结构进行非线性有限元分析的基础上,运用子模型法计算了该桥扁平钢箱梁各关键部位的应力。与实测数据的对比表明:子模型法计算结果准确可靠,能够较真实的反映大桥钢箱梁在各种工况下的受力状态,是分析超大跨悬索桥钢箱梁应力水平及其分布的有效方法。最后分析了该桥钢箱梁的受力特点,为同类流线形扁平钢箱梁的应力分析和设计提供参考依据。 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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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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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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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