共查询到18条相似文献,搜索用时 109 毫秒
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研制了新型的液体表面张力系数测试仪,测量了不同流速时液体的表面张力系数。随液体流速增加,液体的表面张力系数先减小,后迅速增加,当液体流速达到3.0ml/s时,液体的表面张力趋于稳定,该值与理论值较接近。 相似文献
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《物理与工程》2016,(1)
基于特殊性能的磁性液体增设了综合性设计性实验项目,根据项目式教学法初步实现了以学生自我训练为主的教学模式.本文设计了磁性液体磁表面张力系数智能测试仪,研究了均匀磁场中4种不同类型磁性液体的磁表面张力系数随磁感应强度的变化规律.随外加磁场磁感应强度的增强,磁性液体的磁表面张力系数增大,主要是磁场增强了磁性颗粒之间的相互作用力.磁感应强度相同时,载液质量对磁性液体的磁表面张力系数影响较大,载液质量越小,单位体积内融入的磁性颗粒数量越多,导致磁性液体的磁表面张力系数越大.表面活性剂种类对磁性液体磁表面张力系数的影响也较大,由于油酸对磁性颗粒的吸附作用比PBSI-941表面活性剂强,油酸官能团较早吸附在磁性颗粒表面,限制了磁性颗粒进一步长大,导致MFO-4磁性液体磁表面张力系数较小. 相似文献
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A linear free hydroelastic vibration analysis of a frictionless liquid with a free surface contained in a cylindrical tank with a flexible bottom has been performed. The side-wall has been treated as rigid and the effect of surface tension taken into consideration. The container bottom was treated as a membrane, while for the free liquid surface the effect of two contact line conditions has been investigated. One edge condition was that of a slipping contact line, while the other one treated the contact line as fixed, ie., an anchored edge. The vibration characteristics of a membrane-liquid coupled system have been investigated for various system parameters, i.e., membrane tension parameter T, liquid surface tension parameter σ, material density parameter ρ, liquid height ratio ?0 and vibration mode numbers m and n. The degree of coupling between a membrane and a liquid was represented with vibration mode diagrams as well as with frequency diagrams. For axisymmetric coupled vibrations with anchored edge condition, vibration mode exchanging of both a membrane and liquid free surface with membrane bottom tension parameter T has been investigated. An interesting phenomenon which is only observed for a flexible bottom container and an anchored edge free surface condition is presented. 相似文献
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在液膜拉脱过程中,对吊环的受力以及受力的变化情况进行分析,以便正确测量求得液体表面张力,减少α的实验测量误差。 相似文献
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A simple model for size-dependent surface tension of liquid binary alloy droplets has been established based on Bulter’s equation and our model for size-dependent surface tension of pure liquid component. As an example, the surface tension of liquid Bi–Sn alloy droplets are calculated and discussed. The results show that as the size of the liquid alloy droplets decreases, the corresponding surface tension decreases. The component with lower surface tension is enriched in the surface layer at all times while relatively more another component with higher surface tension appear in the surface region when the size decreases. The effect of decreasing size on liquid alloy surface tension is like that of increasing temperature. When size is larger than about 12 nm, the size effect is small and negligible. 相似文献
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Raul E. Ayala Paul A. Hartley Geoffrey D. Parfitt 《Particle & Particle Systems Characterization》1986,3(1):26-31
Particle size enlargement operations often involve the use of a liquid to improve powder cohesiveness. Capillary suction and surface tension forces acting through liquid menisci between particles are the primary source of the cohesive bonding. The strength of these forces, and consequently the strength of the wet agglomerate, is dependent upon the total liquid content, its distribution within the agglomerate, and the powder wettability (characterized by the liquid surface tension and powder/liquid contact angle). The tensile strength of powder compacts containing submicron carbon black particles has been measured as a function of saturation level for several liquids. It is found that the compact strength increases with increasing surface tension for liquids that exhibit a zero contact angle. Above the critical surface tension for wetting a more complicated situation exists where both the surface tension and contact angle are important. 相似文献
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Local pressure is known to be anisotropic across the interfaces separating fluids in equilibrium. Tangential pressure profiles show characteristic negative peaks as a result of surface tension forces parallel to the interface. Nearby attractive forces parallel to the interface are larger than the repulsive forces and, hence, constitute the surface tension. In this work, using molecular dynamics simulations of methane inside nano-scale pores, we show this surface tension behaviour could be significantly influenced by confinement effects. The layering structure, characterised by damped oscillations in local liquid density and tangential pressures, extends deep into the pore and can be a few nanometers thick. The surface tension is measured numerically using local pressures across the interface. Results show that the tension is smaller under confinement and becomes a variable in small pores, mainly controlled by the thickness of the liquid density layering (or liquid saturation) and the pore width. If the liquid saturation inside the pore is high enough, the vapour–liquid interface is not interfered by the pore wall and the surface tension remains the same as the bulk values. The results are important for understanding phase change and multi-phase transport phenomena in nanoporous materials. 相似文献
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Expressions of the radius and the surface tension of surface of tension in terms of the pressure distribution for nanoscale liquid threads
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The expressions of the radius and the surface tension of surface of tension Rs and γs in terms of the pressure distribution for nanoscale liquid threads are of great importance for molecular dynamics (MD) simulations of the interfacial phenomena of nanoscale fluids; these two basic expressions are derived in this paper. Although these expressions were derived first in the literature[Kim B G, Lee J S, Han M H, and Park S, 2006 Nanoscale and Microscale Thermophysical Engineering, 10, 283] and used widely thereafter, the derivation is wrong both in logical structure and physical thought. In view of the importance of these basic expressions, the logic and physical mistakes appearing in that derivation are pointed out. 相似文献
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针对用拉脱法测液体表面张力系数的系统误差较大的系列问题,提出了自动降拉双π丝补偿法.用自动化降拉代替手动提拉,提高了操作过程的稳定性;用双π丝代替π丝,消除了拉膜丝的不光滑点;用突变初态和补偿态作为测量状态,有效地排除了浮力、膜重以及侧丝上的表面张力对实验结果的影响.自动降拉双π丝补偿法得到的实验结果,其精度比拉脱法提高3%. 相似文献