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排序方式: 共有242条查询结果,搜索用时 15 毫秒
101.
Marko Milanez GregF. Naterer Geoff Venn Giles Richardson 《Particle & Particle Systems Characterization》2003,20(1):62-72
Analytical methods are developed and applied to droplet motion, as it relates to aircraft icing. Impinging droplets largely affect the heat balance at an iced aircraft surface, as well as the final ice shape. In this study, a similarity solution of the Eulerian droplet momentum equation is developed. Droplet motion near a flat plate is investigated with a similarity solution. By using scaling, sensitivity, order of magnitude and similarity methods, a momentum displacement of droplets (or particles) due to the presence of the solid surface is predicted. Self similarity of the droplet profiles is established, such that downstream propagation can be expressed in terms of a single independent coordinate. Limiting trends of momentum/drag induced and Blasius‐diffusion profiles are found to identify the spatial range encompassing the droplet motion. The predicted results are successfully compared against the scaling requirements. 相似文献
102.
C. -Q. Tu S. -L. Guo Y. -L. Wang X. -H. Hao C. -M. Chen J. -L. Su 《Radiation measurements》1997,28(1-6):159-162
Bubble damage detectors have been prepared by using polyacrylamide as detector solid and freon as detector liquid. Tests show that the prepared detectors are sensitive to fast neutrons and have proportionality between bubble number and neutron fluence within a certain range of neutron fluence. Therefore, it can be used as a fast neutron detector and a dosimeter. Our experiments also show that the sensitivity of the detector increases with temperature. 相似文献
103.
Jiaming YanAuthor Vitae Ruijin LiaoAuthor VitaeLijun YangAuthor Vitae Jian LiAuthor VitaeBin LiuAuthor Vitae 《Applied Surface Science》2011,257(13):5863-5870
Surface products of oil-impregnated insulation paper during the damage process caused by partial discharge (PD), as well as gas within the cavity, were studied. An optical microscope and a scanning electron microscope (SEM) were used to investigate surface morphology, while an infrared spectroscopy (IR) and an X-ray photoelectron spectroscopy (XPS) were used to study surface products and their components. The volume variation in cavity gas was also analyzed. Furthermore, gas constituents and their relevant contents were studied using a gas chromatography-mass spectrometer (GC-MS). The study results reveal the following: during the PD damage process, the total gas volume and the content of electronegative gasses alternately decline and increase, while discharge types alternate between pulse type and pseudo-glow type (or glow type); “surface droplets” and “crystalline solids” appear on the insulation surface one after another; surface droplets mainly consist of (CO)-group-containing compounds, whereas crystalline solids are mainly carboxylic acids, with carboxyl groups also found in cellulose chains; and the discharge type related to the oxidization of decomposition products is the main factor that determines the state (liquid or solid) of the surface products. 相似文献
104.
A new thermo-diffusive analysis of one-dimensional laminar lean or rich off-stoichiometric premixed spray flames has been performed using a chain branching/chain breaking chemical kinetic scheme and under the assumption that the fuel droplets evaporate in a sharp front. The sensitivity of the flame structure, speed and the location of the evaporation front to the initial droplet load have been demonstrated. A linear stability analysis reveals the way in which the spray's presence modifies the neutral stability curves. 相似文献
105.
106.
A numerical study on viscoelastic droplet migration on a solid substrate due to wettability gradient
This study investigates the viscoelastic effects on droplet migration induced by a wettability gradient on a rigid substrate by a numerical simulation based on OpenFOAM with the volume‐of‐fluid method. The droplets are set with different rheological properties to investigate the effect of the elastic parameters. The Oldroyd‐B model was employed. Quantitative differences in the migration and deformation between Newtonian and viscoelastic droplets were investigated by changing the degree of elasticity. The droplet migration shows conspicuously higher mobility for high elasticity, especially during the accelerating period. Moreover, the displacement and velocity increased with the decrease of a viscoelasticity parameter, and the velocity enhancement was regulated by the elastic instability shown at a high Weissenberg number. In addition, the velocity of the droplet changes more significantly over the range of contact angles of 130° to 60° compared to other wettability‐gradient surfaces. 相似文献
107.
Haixu Chen Weiran Li Youping Lin Dr. Lei Wang Dr. Xiaoman Liu Prof. Dr. Xin Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17101-17108
The biomimetic dynamic behaviours of emulsions are receiving increasing attention from the broad scientific community; however, the spatiotemporal control and functionalization of emulsions based on simple fusion-induced method is rarely mentioned. A design for protein-stabilized oil-in-water droplets and phospholipid-stabilized oil-in-water droplets is described and a substance-diffusion-mediated fusion mechanism proposed within these two different emulsion communities. Significantly, a range of fusion-induced high-order behaviours were successfully demonstrated including competitive fusion, fusion-induced evolution in membrane complexity, and diversified structures with the formation of Janus or various patchy morphologies, fusion-induced membrane maturation, as well as fusion-induced multifunctionalization with a directional motility behaviour. These results highlight the fusion-induced diverse dynamic behaviours in complex emulsions communities and provide a platform for advancing versatile applications of emulsions. 相似文献
108.
《化学:亚洲杂志》2017,12(14):1704-1708
The use of fluorescent markers and probes greatly enhances biological investigations but relies on the provision of an array of fluorophores with diverse properties. Herein we report a novel carborane‐containing coumarin, 5 , which is sufficiently lipophilic to localise in cellular lipid droplets. In non‐polar solvents which show comparable polarities to those of a lipid environment, compound 5 exhibits a fluorescence quantum yield two orders of magnitude greater than found in aqueous solvents, adding a further degree of selectivity to lipid droplet imaging. Compound 5 can stain lipid droplets in ex vivo adipocytes as well as in cultured cells, and can be utilised in flow cytometry as well as confocal microscopy. 相似文献
109.
Han Chen Kaimin Wang Hongsheng Liu Shengqiang Shen 《International Journal of Computational Fluid Dynamics》2013,27(5):222-233
ABSTRACTThe coupled level set and volume of fluid method is applied to the numerical study on the successive impact of double droplets on a super-hydrophobic tube. The impact velocity varies from 0.25 to 2?m/s. These impact processes present spread, retract, rebound, breakup and splash. The out-of-phase impact takes place with the impact velocity from 0.25 to 1.25?m/s, while the in-phase impact takes place with the impact velocity from 1.44 to 2?m/s. With the impact velocity larger than 1.25?m/s, the liquid crown presents and deforms after the trailing droplet impact, then it would gather at the film edge, rebound or break up. When impact velocities range from 1.44 to 1.5?m/s, the finger liquid film presents before the liquid crown appearing. The finger head breaks with the impact velocity of 1.5?m/s during the leading droplet spreading. The zigzag liquid film becomes more obvious for larger velocities. 相似文献
110.
Clusters traverse a gas and collide with gas particles.
The gas particles are absorbed, and the clusters become hosts. If
the clusters are size-selected, the number of guests will be Poisson
distributed. We review this by showcasing four laboratory procedures
that all rely on the validity of the Poisson model. The effects of a
statistical distribution of the clusters' sizes in a beam of
clusters are discussed. We derive the average collision rates.
Additionally, we present Poisson mixture models that also involve
standard deviations. We derive the collision statistics for common
size distributions of hosts and also for some generalizations
thereof. The models can be applied to large noble gas clusters
traversing doping gas. While outlining how to fit a generalized
Poisson to the statistics, we still find even these Poisson models
to be often insufficient. 相似文献