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91.
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Shashank S. Tiwari Swapnil V. Ghatage Jyeshtharaj B. Joshi Bo Kong 《American Institute of Chemical Engineers》2022,68(8):e17725
Multifluid model (MFM) simulations have been carried out on liquid–solid fluidized beds (LSFB) consisting of binary and higher-order polydisperse particle mixtures. The role of particle–particle interactions was found to be as crucial as the drag force under laminar and homogenous LSFB flow regimes. The commonly used particle–particle closure models are designed for turbulent and heterogeneous gas–solid flow regimes and thus exhibit limited to no success when implemented for LSFB operating under laminar and homogenous conditions. A need is perceived to carry out direct numerical simulations of liquid–solid flows and extract data from them to develop rational closure terms to account for the physics of LSFB. Finally, a recommendation flow regime map signifying the performance of the MFM has been proposed. This map will act as a potential guideline to identify whether or not the bed expansion characteristics of a given polydisperse LSFB can be correctly simulated using MFM closures tested. 相似文献
93.
Xue Zhang Jin Du Guosheng Su Peirong Zhang Yujing Sun Chongyan Zhang Xiangmin Kong 《International Journal of Applied Ceramic Technology》2022,19(3):1354-1366
Mo2NiB2 is a kind of cermet with excellent mechanical properties, stable chemical properties, and excellent corrosion resistance and is often used in wear-resistant application fields, such as injection molding machine parts, can making tools and hot copper extruding dies. The brittleness of Mo2NiB2-based cermets limits their wide application. Mo2NiB2-based cermets were prepared by the vacuum sintering method, the effect of SiC whiskers (SiCw) on the microstructure and mechanical properties of cermets was investigated, and the toughening mechanism of SiCw on cermets was further discussed. The results indicate that with increasing SiCw content, the indentation fracture toughness (KIC), transverse fracture strength (TRS), and Vickers hardness (HV) of the cermets first increase and then decrease. The HV, TRS, and indentation fracture toughness of Mo2NiB2-based cermets with 0.5 wt% SiCw are 1 113 HV, 1 620 MPa, and 27.97 MPa·m1/2, respectively, which are 16.8%, 22.7%, and 25% higher than those without SiCw. In the sliding friction tests, Mo2NiB2-based cermets with 0.5 wt% SiCw have the smallest friction coefficient, low wear rate, and high wear resistance. SEM observation and analysis of the crack path and fracture surface showed that the toughening mechanism is whisker bridging, crack deflection, microcrack toughening, and whisker pull-out. The results indicate that the addition of 0.5 wt% SiCw can effectively improve the mechanical properties of Mo2NiB2-based cermets and further expand the application space of Mo2NiB2-based cermets. 相似文献
94.
Xuxin Zhao Kunling Yang Zhou Liu Ho Cheung Shum Tiantian Kong 《Frontiers of Chemical Science and Engineering》2022,16(11):1681
Bubbles and foams are ubiquitous in daily life and industrial processes. Studying their dynamic behaviors is of key importance for foam manufacturing processes in food packaging, cosmetics and pharmaceuticals. Bare bubbles are inherently fragile and transient; enhancing their robustness and shelf lives is an ongoing challenge. Their rupture can be attributed to liquid evaporation, thin film drainage and the nuclei of environmental dust. Inspired by particle-stabilized interfaces in Pickering emulsions, armored bubbles and liquid marble, bubbles are protected by an enclosed particle-entrapping liquid thin film, and the resultant soft object is termed gas marble. The gas marble exhibits mechanical strength orders of magnitude higher than that of soap bubbles when subjected to overpressure and underpressure, owing to the compact particle monolayer straddling the surface liquid film. By using a water-absorbent glycerol solution, the resulting gas marble can persist for 465 d in normal atmospheric settings. This particle-stabilizing approach not only has practical implications for foam manufacturing processes but also can inspire the new design and fabrication of functional biomaterials and biomedicines. 相似文献
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结合沈阳金秋医院新建疗养病房楼单体设计,对现代医疗建筑中亲和力的塑造进行了有意义的探讨,以寻找医疗建筑中失落的人文关怀;试图从功能、空间、形式、光影、细部的角度阐述亲和力塑造的必要性,以期构建当代人性化的建筑空间。 相似文献
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98.
城市固体废弃物的动力特性及参数确定 总被引:1,自引:0,他引:1
参照杭州天子岭填埋场城市固体废弃物(MSW)主要成分,人工配制固体废弃物试样,利用中型动三轴试验仪研究其在较大应变范围内MSW的动力特性。由于MSW的高压缩性,初始孔隙比不同对试样的动力特性影响不大。建议了归一化动剪切模量和阻尼比与动剪应变依赖关系的取值范围和平均值曲线,并将其与不同塑性指数黏土的动力特性进行对比,可以发现MSW材料剪切模量衰减和阻尼比曲线较好的呈现出中塑性黏土的特征。最后,对城市固体废弃物的动剪切模量Gd和阻尼比D随动剪应变dγ的变化曲线进行了拟合,并给出了拟合公式的参数取值。 相似文献
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100.