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空心玻璃微珠填充固体浮力材料的制备及性能研究 总被引:1,自引:0,他引:1
以双酚A环氧树脂E51为基质原料,甲基四氢苯酐为固化剂,K25空心玻璃微珠为轻质填充物,采用模压成形的方法制备了空心玻璃微珠填充固体浮力材料。研究了玻璃微珠的填充率对体系粘度、浮力材料的密度、抗压强度及耐静水压件能的影响。结果表明,低密度空心微珠的引入,有效降低了固体浮力材料的密度,并且随着玻璃微珠填充量的增大,材料的理论计算密度与实际密度的偏差逐渐变大;浮力材料的单轴压缩强度和耐静水压强度随着空心玻璃微珠填充量的增大而降低,当玻璃微珠填充量超过18%时,材料性能下降幅度增大。 相似文献
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以双酚A环氧树脂E51为基质原料,甲基四氢苯酐为固化剂,K25空心玻璃微珠为轻质填充物,采用模压成形的方法制备了空心玻璃微珠填充固体浮力材料。研究了玻璃微珠的填充率对体系粘度、浮力材料的密度、抗压强度及耐静水压性能的影响。结果表明,低密度空心微珠的引入,有效降低了固体浮力材料的密度,并且随着玻璃微珠填充量的增大,材料的理论计算密度与实际密度的偏差逐渐变大;浮力材料的单轴压缩强度和耐静水压强度随着空心玻璃微珠填充量的增大而降低,当玻璃微珠填充量超过18%时,材料性能下降幅度增大。 相似文献
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环氧树脂基固体浮力材料的制备及性能研究 总被引:1,自引:0,他引:1
实验采用低密度空心玻璃微珠(HGMS)填充脂环族环氧树脂E-4221制备固体浮力材料。讨论了环氧树脂E-4221体系的固化工艺制度和树脂体系配方对固化环氧树脂材料强度的影响,测得固化树脂产物压缩强度范围值100~150 MPa。分析了树脂配方以及玻璃微珠体积含量对最终固体浮力材料性能的影响,通过优化条件制备出抗压强度在40~70 MPa之间,密度范围在0.5~0.7 g/cm3,吸水率低于0.2%的固体浮力材料,最后对浮力材料的压缩断面做了简要分析。 相似文献
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使用浓H_2SO_4/浓HNO_3的混酸体系对碳纤维(CF)的表面进行处理得到氧化碳纤维(OCF)。采用超声分散和模具浇注成型法制备氧化碳纤维/空心玻璃微珠(HGMs)/环氧树脂固体浮力材料,研究了材料的密度、抗压强度、吸水率和断面形貌。使用ABAQUS数值模拟软件,建立了碳纤维增强固体浮力材料的模型,研究了碳纤维对材料应力分布的影响。结果表明,碳纤维经过氧化后,表面形成了羟基和羧基等基团,提高了自身与环氧树脂的界面结合状态。随着氧化碳纤维含量的增加,复合材料的占空比逐渐提高,但密度变化不大,而其抗压强度呈现先升高后降低的趋势。当碳纤维含量为5%(质量分数)时,抗压强度达41MPa,提高约13.8%。固体浮力材料吸水率随碳纤维含量增加而提高,但所有试样的吸水率均小于2%。复合材料模型受压后的应力云图表明,碳纤维能够有效代替固体浮力材料基体承载很大一部分载荷,空心玻璃微珠球壳所受应力降低,减少了空心玻璃微珠破碎和裂纹源的产生,从而对固体浮力材料起到增强作用。 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