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51.
Multimedia Tools and Applications - In recent years, various chaotic maps have been used for image encryption. However, most of these image encryption algorithms entail a lot of floating-point... 相似文献
52.
空调器采用翅片管式换热器作为蒸发器,在制冷工况下换热器表面发生析湿及粉尘沉积,导致性能衰减。建立湿翅片表面粉尘颗粒物沉积过程的数学模型,模拟冷凝水捕集颗粒物以及湿积灰层黏附颗粒物的过程。被冷凝水捕集的颗粒物数量等于运动轨迹与水表面轮廓会出现相交的入射颗粒物的数量;后续的入射颗粒物与湿积灰层碰撞时,部分入射颗粒物会发生沉积且部分被碰撞的已沉积湿颗粒物会发生移除,这两部分的颗粒物数量相减即为被湿积灰层黏附的颗粒物数量。模拟与实验结果的对比表明,预测的湿积灰层形状与实验照片的吻合度较好,预测的单位面积颗粒物沉积质量与91%的实验数据之间的误差在±20%之间,平均误差为11.8%。 相似文献
53.
Yejun Wu Bowen Yan Juan Zhou Huizhang Lian Xiaojun Yu Jianxin Zhao Hao Zhang Wei Chen Daming Fan 《Journal of food science》2020,85(10):3282-3292
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Although Mg alloy possesses high specific strength, low density, and good biocompatibility, poor corrosion resistance hinders its further applications. In the present study, an innovative protective layer against corrosion was prepared on the AZ31 Mg alloy via alkali pretreatment followed by vanillic acid treatment. The alkali pretreatment supplied –OH for the AZ31 Mg alloy surface to react with vanillic acid. The vanillic acid treatment played a crucial role in enhancing the corrosion resistance due to the excellent ability to act as a barrier and retard aqueous solution penetration, which effectively isolated the underlying Mg alloy from the corrosive environment. The corrosion current density of alkali and vanillic acid-treated Mg alloy (AZ31V) almost showed two orders of magnitude lower values in comparison with that of the AZ31 Mg alloy, and the corrosion potential of AZ31V Mg alloy increased from −1.41 to −1.25 V. The immersion tests proved that there was no occurrence of severe corrosion. Hence, the alkali pretreatment and vanillic acid treatment may represent a promising method to improve the corrosion resistance of Mg alloy. 相似文献
56.
Weihong Tian Hao Su Chuansong Wu 《The International Journal of Advanced Manufacturing Technology》2020,107(1):59-71
Al/Cu dissimilar joint has been widely produced by using friction stir welding (FSW), but the weld quality remains limited. A recently developed ultrasonic 相似文献
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Machine Learning - Recently, the $${ Tensor}~{ Nuclear}~{ Norm}~{ (TNN)}$$ regularization based on t-SVD has been widely used in various low tubal-rank tensor recovery tasks. However, these models... 相似文献
59.
AbstractThe reabsorption characteristics of the lignite treated by low and high temperature drying process were addressed in the paper. The information about the moisture form, functional groups, effective water-filled porosities and equilibrium moisture content of the lignite before and after the drying process was investigated using Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and a self-made reabsorption device, respectively. The results show that the low drying temperature (140, 190, 230?°C, 10?min, N2) has little impact on the effective water-filled porosities of the resulted samples, whereas it has a great influence on the main oxygen-containing functional groups, which amount firstly decreases and then increases with the drying temperature increasing. In the case of the lignite samples dried under high-temperature (600, 700, 800?°C, 30?s, N2), the amount of the effective water-filled porosity of the sample decreases and the amount of oxygen-containing functional groups increases as the temperature increasing. The reabsorption capability of the high temperature dried sample is much lower than that of the sample treated under low drying temperature. The reabsorption characteristics of the low-temperature dried samples are affected by the amount of the oxygen-containing functional groups, while the effective water-filled porosity is main factor for the lignite samples derived from high temperature drying process. Moreover, the work gives a good evidence that the high-temperature drying process is an effective choose for lignite upgrading. 相似文献
60.
以板状刚玉、尖晶石细粉和活性α-Al2O3微粉为主要原料,使用HiPerCem水泥作为结合剂制备刚玉-尖晶石浇注料,对比研究了HiPerCem水泥与Secar71及CMA72水泥在浇注料中的凝结行为及其对浇注料常温物理性能、抗渣性能的影响.结果 表明,在保持引入浇注料中一铝酸钙含量为1.8%,尖晶石含量为10%的情况下,HiPerCem水泥结合浇注料的凝结速度居中,脱模及烘干强度较另外2种水泥结合浇注料的低.抗渣侵蚀实验表明,以HiPerCem水泥为结合剂的浇注料因引入的CaO含量较CMA72和Secar71水泥结合浇注料低,大尺寸气孔少,具有较好的抗渣性;而CMA72水泥结合浇注料因试样中大尺寸气孔比例较高,熔渣渗透严重,未能发挥出其水泥中微晶尖晶石相改善抗渣性的优势. 相似文献