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91.
92.
Observation of Newton black film (NBF) in foam film is possible only with a certain probability W which depends on the concentration C of surfactant in the solution and on the time ta during which adsorption of surfactant at the solution/air interface has taken place. In the paper, the W(C,ta) dependence is derived and used to analyze the effect of ta on the critical surfactant concentration Cc below which NBF in foam film practically cannot be observed. An expression for the Cc(ta) function is obtained which reveals that Cc decreases substantially with increasing ta. This expression is found to describe well experimental Cc(ta) data for foam films obtained from aqueous solution of the therapeutic surfactant INFASURF. 相似文献
93.
Effects of film structure on electrochromic properties of the multilayer films containing polyoxometalates 总被引:2,自引:0,他引:2
Bingbing Xu Lin Xu Guanggang Gao Weihua Guo Shuping Liu 《Journal of colloid and interface science》2009,330(2):408-414
Multilayer films of tungstophosphate anion (P2W18) and poly(allylamine hydrochloride) (PAH) were fabricated on quartz and ITO substrates by layer-by-layer self-assembly method. These films were characterized by UV–vis spectroscopy, cyclic voltammetry (CV), chronoamperometric (CA), chronocoulometry (CC) and atomic force microscopy (AFM). The effects of film structure on multilayer electrochromic properties were investigated. The electrochromic responses of the composite films were related to the surface coverage of anion and multilayer thickness. It was found that higher concentration of polycation and anion, or adding salt to the polycation solution used for multilayer film preparation led to thicker and denser film structure which improved optical contrast and coloration efficiency whereas prolonged response time. 相似文献
94.
A process has been developed by which mean velocity and concentration measurements can be used to determine optimal turbulent diffusivity values for an angled jet in cross-flow configuration. This configuration has applications in film cooling for gas turbine blades. The measurements, obtained by magnetic resonance imaging techniques, provide 3D time-averaged velocity and concentration fields. The mean velocity field is fed into a Reynolds-Averaged Advection Diffusion solver, which uses a turbulent diffusivity model to solve for the mean coolant concentration distribution. This distribution can be compared to the experimentally-obtained concentration field by means of an error metric that quantifies the difference between the computational and experimental concentration fields. By minimizing this error, an optimal value of the turbulent diffusivity can be determined. This optimized distribution is then compared to a RANS simulation to evaluate the relative contribution to error of the turbulent momentum flux model versus the turbulent scalar flux model. 相似文献
95.
96.
红外光谱分析丙烯酸树脂包膜尿素膜降解特征 总被引:1,自引:0,他引:1
采用傅里叶变换红外光谱吸收(FTIR)方法分析丙烯酸树脂包膜尿素及与生化抑制剂结合的四种肥料在棕壤中膜降解特征,尝试利用红外光谱技术分析丙烯酸树脂膜降解特征,为包膜尿素肥料的应用提供科学依据。分析表明,成膜的化学成分,分子结构和膜组成没有因不同种生化抑制剂的加入而受到影响。膜特征峰出现在3 479~3 195,2 993~2 873,1 741~1 564,1 461~925和850~650cm-1之间,主要是CH3,CH2的—C—H,—OH,C—O,C—C,C—O—C,CO,CC的不对称、对称伸缩振动吸收,峰面随时间变化由平到尖,由宽到窄,吸收强度因化学键量变强弱不一。60d前四种肥料膜红外吸收光谱没有明显区别,膜降解缓慢;而60d后降解速度加快,以120d降解速度最快,310d后四种肥料膜主要分子结构没有实质性改变,膜材料主要成分在棕壤中降解十分缓慢,降解速度并没有明显受到不同生化抑制剂的影响。降解特征可以用红外吸收光谱测定与描述,红外光谱能够描绘膜降解动态,物质化学基团变化,降解速度的差别。 相似文献
97.
红外光谱分析醋酸酯淀粉包膜尿素膜降解特征 总被引:1,自引:0,他引:1
采用傅里叶变换红外吸收光谱(FTIR)方法分析醋酸酯淀粉包膜尿素及与生化抑制剂结合的四种肥料在棕壤中膜降解特征,为包膜尿素肥料的应用提供科学依据。分析表明,膜化学成分,分子结构和膜组成没有因加入不同的抑制剂而改变。膜特征峰主要是H-O,—OH,CO2,C=O,—CH2,—CH3,C—O,C—O—H,C—O—C的不对称、对称伸缩振动吸收。在棕壤中,最高峰吸收强度总趋势0>15>30>60>90>120>150>310d,前15d降解相对缓慢。150d大部分膜物质已降解。经过310d,膜主要官能团或分子结构发生了实质性改变,不同抑制剂对膜降解速度没有显著影响。红外吸收光谱完全可以测定与描述醋酸酯淀粉膜降解特征,并可揭示膜降解速度差异。 相似文献
98.
Polymeric surfactants are amongst the most widespread of all polymers. In nature, proteins and polysaccharidescause self organization as a result of this surfactancy; in industry, polymeric surfactants play key roles in the food, explosivesand surface coatings sectors. The generation of useful nano- and micro-structures in films and emulsions as a result ofpolymer amphiphilicity and the application of mechanical stress is discussed. The use of X-ray and neutron small anglescattering and reflectivity to measure these structures and their dynamic properties will be described. New results on linear and dendritic polymer surfactants are presented. 相似文献
99.
《Analytical letters》2012,45(10):1796-1806
In this paper, we present a one-step aqueous self-polymerization strategy to prepare surface molecularly imprinted poly(dopamine) (PDA) film. The method is simple and convenient compared with the “template-guided” surface molecularly imprinted synthesis method and the layer-by-layer self-assembly and the surface-grafted molecularly imprinted synthesis methods. The molecularly imprinted PDA films could selectively bind the template molecules (4-Hydroxybenzoic acid as a model), and bisphenol A (BPA) imprinted PDA films were also investigated. Meanwhile, the 2-dimension imprinted film material was used very conveniently. 相似文献
100.
In this paper, a new two-fluid two-component computational fluid dynamics (CFD) model is developed to simulate vertical upward two-phase annular flow. The two-phase VOF scheme is utilized to model the roll wave flow, and the gas core is described by a two-component phase consisting of liquid droplets and gas phase. The entrainment and deposition processes are taken into account by source terms of the governing equations. Unlike the previous models, the newly developed model includes the effect of liquid roll waves directly determined from the CFD code, which is able to provide more detailed and, the most important, more self-standing information for both the gas core flow and the film flow as well as their interactions. Predicted results are compared with experimental data, and a good agreement is achieved. 相似文献