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61.
高速搅拌对淀粉/聚乙烯醇共混物薄膜性能的影响 总被引:8,自引:0,他引:8
通过高速搅拌,将淀粉与聚乙烯醇进行溶液共混,制备了淀粉/PVA共混薄膜。测定了高速搅拌前后共混薄膜的力学性能。透明性,耐水性及生物降解性。结果表明,高速搅拌改善了淀粉/PVA薄膜的力学性能,透明性与耐水性,并可提高共混膜的全用稳定性。 相似文献
62.
In this paper, the unsteady heat transfer over an impulsively started wedge is investigated. The mixed convection, namely, the thermal boundary-layer growth is caused by the sudden increase of the surface temperature as it is set into motion. The analytic approximations with high accuracy are given using the Homotopy–Padé technique, which agree well with the numerical results using an implicit finite-difference method known as Keller–Box method. It is found that the Homotopy–Padé approximations have no relation to the auxiliary parameters ?f and ?g, which play important roles in the homotopy analysis method. 相似文献
63.
In order to tackle the shortcomings of high brittleness,hard graphitization,and poor oxidation resistance resulted from carbonization of phenolic resin of Mg O- C refractories, effects of 2 mass% spherical Ni, and2 mass% spherical Ni plus 7. 5 mass% Al composite powder on microstructure of the secondary carbon in Mg O- C refractories matrix were investigated. The results show that a large number of carbon whiskers form after the carbonization of phenolic resin with Ni powder;in the Mg O- C refractories matrix with only Ni powder,the carbon microspheres form at all treatment temperatures and change slightly with the temperature rising;the carbon whiskers begin to generate in the specimens with composite powder at 1 000 ℃,the diameter of the carbon whiskers is about 0. 4- 0. 5 μm,and the length is about 3- 4 μm,and the formed carbon whiskers increase gradually with the temperature rising. 相似文献
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阐述了中,高碳钢优质线材用方坯的表面质量要求,介绍了国外一些钢厂采用的表面清理工艺和表面缺陷在线检测与清理设备,提出了武钢添置优质线材用方坯表面清理设备的有关建议。 相似文献
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Based on the theory of plasma continuous radiation,the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained.During the development process of a return stroke of ground flash,the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments.The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity.It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak.The peak temperature of the two spectra is close to 25 000 K.To be compared with the result of discrete spectrum,the electron temperature is fitted by the O I line and N II line of the spectrum respectively.The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information,and the low temperature at the high band closes to the calculation result of the atomic line,at a low band is lower than the calculation of the atomic line,which reflects the temperature of the luminous channel of the outer corona. 相似文献
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锚杆支护是围岩加固的一种重要形式,而锚杆的预紧力则是提高加固质量的重要的环节。但根据现行的工程应用情况,对此重要环节反倒没有引起足够的重视,从而增加了工程质量潜在事故的可能性。因此,本文针对锚杆预紧力常常不足的情况,或者当时满足,而一段时间后又因应力松驰等其他作用所再次导致预紧力不足的现象,通过在锚杆顶端与靠近锚杆处的托盘上分别安装一个同向振动的加速度传感器,利用二者之间是否发生同步振动的动力响应,即相位频谱和振动频率差,对锚杆预紧力是否满足进行快速、准确地定性判断,从而为工程质量监管提供一种可行的简便方法。 相似文献
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