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浸渍法测量片状结晶性塑料密度的不确定度评估 总被引:1,自引:0,他引:1
按照GB1033—186中的浸渍法测量5种片状结晶性塑料的密度,分析了塑料密度测量的影响因素,如浸渍浓度、测量温度、样品称量等。利用测试数据及JJF1059—1999对浸渍法测量片状结晶性塑料密度的不确定度进行分析评估,得出测量结果的扩展不确定度为0.0073g/cm3。 相似文献
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依据GB1033-80塑料密度和相对密度试验方法分析了PVC-U管材密度测量过程中不确定度的来源,对密度测量不确定度进行了评估。该测量过程所产生的测量不确定度主要来源于砝码误差和天平横梁不等臂性误差。 相似文献
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依据GB1033-1986《塑料密度和相对密度试验方法》分析了PVC-U管材密度测量过程中不确定度的来源,对不确定度进行了评估,结果表明:测量不确定度主要来源于砝码误差和横梁不等臂性误差,测量重复性误差和天平示值变动性误差对测量不确定度的影响较小。 相似文献
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依据GB/T 1463-2005纤维增强塑料密度和相对密度试验方法分析了电缆用玻璃钢保护管密度测量过程中不确定度的来源,对密度测量不确定度进行了评估。该测量过程所产生的测量不确定度主要来源于试样在空气中的质量、试样悬挂在水中的质量和电子天平式示值误差。 相似文献
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《高科技纤维与应用》2016,(1)
采用氯化锌溶液配置密度梯度柱测定碳纤维密度,并评定其测量不确定度。结果表明:密度测量不确定度来源于密度梯度管内浮子间距、刻度读数精度、浮子密度校准精度和相邻两浮子密度差;减小密度梯度管配置时高低密度溶液密度差,可以有效降低测量不确定度。 相似文献
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采用《测量不确定度评定与表示》对密度梯度柱法测定聚乙烯密度的不确定度进行了评定。分析了不确定度的主要来源,包括标准曲线引入的不确定度、测量重复性引起的不确定度、温度不确定度及标准浮子的不确定度,并评估了一个样品测量结果的合成标准不确定度和扩展不确定度。 相似文献
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徐振荣 《化工自动化及仪表》1982,(5)
高压聚乙烯装置高压分离器γ射线液位测量中,随机的气相密度使γ射线强度造成大量衰减。本文用最小二乘法原理确定密度校正式中的系数,由常规仪表组成带有密度校正的液位测量控制系统,有效地提高了测量精度。 相似文献
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As part of the Big Bend Regional Aerosol Visibility and Observation study (BRAVO) in July-October 1999, dry aerosol size distributions were measured over the size range of 0.05 < Dp < 20 w m using a TSI differential mobility analyzer (DMA), a PMS LASAIR 1003 optical particle counter (OPC), and a TSI aerodynamic particle sizer 3320 (APS). Extensive calibrations were performed to characterize the response of the OPC and APS to particles of different size and composition. This paper describes a new method that was developed to align size distributions in the instrument overlap regions, allowing for the retrieval of aerosol real refractive index and effective density. To validate the method, retrieved particle real refractive index was compared with volumeweighted model estimates based on measured PM 2.5 chemical composition. The study average retrieved real refractive index was m r = 1.566 - 0.012, and the average computed PM 2.5 refractive index was m r = 1.56 - 0.02; the agreement is well within experimental uncertainties. The average value of computed PM 2.5 bulk density was 1.85 - 0.14 g cm -3 . The average value of retrieved effective density, a function of particle dynamic shape factor, was 1.56 - 0.12 g cm -3 . The comparisons of effective density to computed bulk density suggested an average particle dynamic shape factor of h = 1.2. Sensitivity studies showed that real refractive index could be retrieved with uncertainties on the order of 2-3%, and effective density was retrieved with uncertainties on the order of 20-30%. 相似文献
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球形锂离子电池正极材料-LiCoO2、LiNiO2、LiMn2O4及其掺杂材料具有堆积密度大、体积比容量高、电化学性能和加工性能优异等突出优点,是锂离子电池正极材料的重要发展方向。对以上球形正极材料的制备方法进行了归纳研究,希望能够为从事电池材料的研究者提供借鉴。 相似文献
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新型云爆剂的加速热老化行为及寿命预估 总被引:1,自引:0,他引:1
采用加速老化试验方法,研究了新型云爆剂在高温加速老化条件下的老化行为,并对其使用寿命进行预估。结果表明,随老化时间的增加,新型云爆剂密度均匀性明显降低,而交联密度值呈现先减小后增大再减小的趋势,且老化温度越高,交联密度峰值越大。在55、65、75和85℃老化温度下,样品交联密度的最大值分别为3.084 3×10~(-5)、3.093 2×10~(-5)、3.196 4×10~(-5)、3.288 1×10~(-5)mol/mL。以铝粉活性降低8%作为新型云爆剂的失效判据进行寿命预估时,推算新型云爆剂在25℃下的使用寿命大于14年。 相似文献
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用稳态法研究岩矿棉隔热材料热系数与密度及温度的关系,结果表明,在一定的工艺条件下,对于化学组成稳定确定的岩矿棉隔热材料,在一个大气压及确定的温度下,在80-100kg/m^3的密度范围将出现导热系数最小值;其导热系数随着温度的增加而非线性地增大,并从理论上提高其经济性的途径,这为陶瓷窑炉保温结构的热设计提供了科学依据。 相似文献
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A method is proposed for reconstruction of a non-negative piecewise continuous density distribution from a solution obtained by the high order moment conserving method of classes (HMMC), presented in our earlier papers [Alopaeus, V., Laakkonen, M., Aittamaa, J., 2006]. Solution of population balances with breakage and agglomeration by high order moment-conserving method of classes. Chemical Engineering Science 61, 6732-6752; Alopaeus, V., Laakkonen, M., Aittamaa, J., 2007. Solution of population balances with growth and nucleation by high order moment-conserving method of classes. Chemical Engineering Science 62, 2277-2289.]. The resulting distribution is strictly non-negative, and the overall distribution moments obtained by HMMC are conserved very accurately. The distribution is reconstructed by using the positive region of HMMC as an initial estimate for the continuous density distribution. This estimate is then refined by transforming the abscissas and scaling the ordinates of the density distribution so that the distribution moments are as close to the original solution as possible. The method is tested with a number of numerical examples. These cases are chosen due to their tendency to produce oscillations in HMMC, or due to their nature of producing multimodal distributions. It is shown that when the reconstruction algorithm is applied to the HMMC solution, the analytical density distribution is captured extremely well. This is true even in cases where the width of the analytical distribution is only a fraction of the original HMMC grid size. Multimodal population density distributions can also be reconstructed accurately from a HMMC solution with a reasonably small number of grid points, without a need to assume any basis functions for the reconstruction. 相似文献