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structure parameters, including coordination number, aspect ratio and shape factor, on gas-water flow, was investigated. The present simulation results show that with the increment of coordination number, gas flow ability in network improves and the effect of invading water on blocking gas flow weakens. The smaller the aspect ratio is, the stronger the anisotropy of the network is, resulting......
: T-shaped spur dike; flow pattern; submergence ratio; SSIIM model 1 Introduction Spur dikes are hydraulic engineering structures for preserving the desired water depth, deflecting the main current..., but by increasing the submergence ratio, due to passing of flow over the spur crest, the longitudinal velocity increases at upstream and downstream sections and even at the spur dike axis section. So......
, it cannot basically improve the metal flow and avoid the defects; after the guiding angle is employed, the metal in the deforming area is extruded twice with a lower extrusion ratio, which greatly...J. Cent. South Univ. Technol. (2009) 16: 0738-0742 DOI: 10.1007/s11771-009-0122-3 Deformation division of metal flow behavior during extrusion process of 7075 aluminum alloy LI Feng(李 峰)1, CHU......
, and the dimensionless permeability coefficient (the ratio of measured instantaneous permeability to the absolute permeability in the range of [0, 1]) was introduced to achieve the nonlinear flow process by correcting...J. Cent. South Univ. (2012) 19: 1980-1987 DOI: 10.1007/s11771-012-1235-7 Nonlinear flow numerical simulation of low-permeability reservoir YU Rong-ze(于荣泽)1, BIAN Ya-nan(卞亚南)1, ZHOU Shu(周舒)2......
CH4检测元件中Pd/Al2O3催化剂的制备及反应性能 刘建周1,刘凤丽1,于海蔚1,刘军1 (1.中国矿业大学,化工学院,江苏,徐州,221008) 摘要:为提高矿井CH4浓度检测中催化元件的稳定性和可靠性,针对催化元件中催化剂性能这一核心问题进行研究是解决问题的关键.对催化剂结构的表征以及对催化元件工作性能和催化剂反应性能进行了测试,结果表明:经900℃焙烧处理的催化剂载体Al2O3具有适宜于反应的颗粒分散度与孔径分布,催化元件表现出较好工作性能.采用真空干燥处理制备的负载量为3%的Pd/Al2O3催化剂具有较高的反应活性;但助剂的加入使得反应活性有所降低;采用HCl作竞争吸附剂可使活性组分均匀分布于Al2O3内孔;载体的二次成型工艺在一定程度上降低了电桥的零点漂移,提高了催化元件的稳定性. 关键词:催化元件; CH4检测; Pd/Al2O3催化剂; [全文内容正在添加中] ......
J. Cent. South Univ. (2021) 28: 1534-1545 DOI: https://doi.org/10.1007/s11771-021-4713-y Improved designed method of pervious concrete based on optimal volume ratio of paste to aggregate BA Ming... concrete. The improved design method is mainly based on the optimal volume ratio of paste to aggregate (VRPA), which was determined by testing the average thickness of cement paste coating aggregate......
shows that the filling ratio of 60% gives the highest inside pressure magnitude at maximum number of pressure frequency at any of set evaporator temperature and the lowest heat flow resistance is achieved at 60% filling ratio. Key words: oscillating heat pipe; pressure fluctuation; heat flow resistance; filling ratio 1 Introduction It is well established that oscillating heat pipes (OHPs) are widely......
New approach for modeling flow stress of aluminum alloy 6A10 considering temperature variation LI Xue-song(李雪松), WU Lai-zhi(伍来智), CHEN Jun(陈 军), ZHANG Hong-bing(张鸿冰) National Die...; Abstract: The flow stress behavior of aluminum alloy 6A10 was studied......
Discussion and prediction on decreasing flow stress scale effect SHEN Yu(申 昱), YU Hu-ping(于沪平), RUAN Xue-yu(阮雪榆) National Die and Mold CAD Engineering Research Center, Shanghai Jiaotong... theory and surface layer model, relation of flow stress to billet dimension and grain size was built, and rationality of derived relation was verified with tensile tests of different size billets......
aspect ratio (ratio of flow length to diameter). A micro precision casting technology based on investment casting using centrifugal method was investigated. The micro parts of Zn-4%Al alloy with an aspect ratio up to 200 was produced at the centrifugal speed of 1 500 r/min and the mold temperature of 270 ℃. The investigations on the relationship between flow length and rotational speed were carried......