排序方式: 共有16条查询结果,搜索用时 31 毫秒
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通过酸碱中和反应制备了阴/阳离子表面活性剂十四烷基三甲基月桂酸铵, 发现其对石蜡油/水体系具有很强的乳化能力, 通过简单振荡便能形成均一、稳定的乳液. 光学显微镜观察发现乳液液滴的直径从几微米到几百微米不等, 形成密堆积结构. 增大表面活性剂含量使液滴的平均尺寸和多分散度降低. 流变学研究表明, 乳液具有明显的剪切稀释行为, 在同一水体积百分含量下, 随表面活性剂含量的增加, 乳液粘度增大, 且表现出一定的屈服应力. 振荡剪切结果表明乳液具有明显的粘弹性, 在整个频率测量范围内, 弹性模量均高于粘性模量. 此外, 我们还考察了水体积百分含量对乳液性能的影响. 相似文献
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In the presence of closely located inclusions of the extreme material property, the physical fields, such as the electric field and the stress tensor, may be concentrated and arbitrarily large in the narrow region between two inclusions. Recently there has been significant progress on the quantitative characterization of the field concentration in the contexts of electrostatics(Laplace equation), linear elasticity(Lamé system), and viscous flow(Stokes system). This paper is to review such progress in a coherent way. 相似文献
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Kazuya Okada 《Molecular physics》2017,115(6):683-701
We have investigated the aggregate structure of a suspension composed of magnetic particles with a cubic geometry by means of Monte Carlo simulations. From the viewpoint of application to the technology of surface modification, we have considered a quasi-two-dimensional suspension in thermodynamic equilibrium. As the magnetic interaction strength is increased, the effects of the thermal energy are reduced and the particles tend to aggregate together. These aggregates of cubic particles are not chain-like, but are designated as closely packed clusters. An applied magnetic field tends to enhance the formation of clusters along the field direction but does not significantly regularise the internal structure of the cluster. This is mainly due to the preference of a face-to-face contact configuration for the alignment of particles with cubic geometry. The regime of the internal structure of aggregates has a significant effect on the characteristics of the alignment of the magnetic moments with regard to the external magnetic field direction. Our simulations indicate that larger closely packed clusters are formed with increasing volumetric fraction, whereas the internal structure of the closely packed clusters is not found to be significantly influenced by the change in the volumetric fraction. 相似文献
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We report a comprehensive analysis of the ground-state properties of axisymmetric toroidal crystals based on the elastic theory
of defects on curved substrates. The ground state is analyzed as a function of the aspect ratio of the torus, which provides
a non-local measure of the underlying Gaussian curvature, and the ratio of the defect core energy to the Young modulus. Several
structural features are discussed, including a spectacular example of curvature-driven amorphization in the limit of the aspect
ratio approaching one. The outcome of the elastic theory is then compared with the results of a numerical study of a system
of point-like particles constrained on the surface of a torus and interacting via a short-range potential.
Electronic supplementary material Supplementary material in the form of a pdf file available from the journal web page at
and are accessible for authorised users. 相似文献
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文[1]证明了定义在有界闭集上的函数K<1集压缩映象是紧压缩映象,本文主要对定义在有界开集的闭包上的函数K<1集压缩映象场的拓扑度数的性质进行讨论. 相似文献
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The closely coupled approach combined with the finite volume method (FVM) solver and the finite element method (FEM) solver is used to investigate the fluid-structure interaction (FSI) of a three-dimensional cantilevered hydrofoil in the water tunnel. The FVM solver and the coupled approach are verified and validated by comparing the numerical predictions with the experimental measurements, and good agreement is obtained concerning both the lift on the foil and the tip displacement. In the noncavitating flow, the result indicates that the growth of the initial incidence angle and the Reynolds number improves the deformation of the foil, and the lift on the foil is increased by the twist deformation. The normalized twist angle and displacement along the span of the hydrofoil for different incidence angles and Reynolds numbers are almost uniform. For the cavitation flow, it is shown that the small amplitude vibration of the foil has limited influence on the developing process of the partial cavity, and the quasi two-dimensional cavity shedding does not change the deformation mode of the hydrofoil. However, the frequency spectrum of the lift on the foil contains the frequency which is associated with the first bend frequency of the hydrofoil. 相似文献
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密频近线性系统2阶超谐共振Hopf分叉 总被引:1,自引:0,他引:1
研究了一个两自由度密频近线性系统2阶超谐共振Hopf分叉,揭示出由于密频内共振的作用,系统将存在较复杂的动力学行为。 相似文献
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A Universal Matrix Perturbation Technique for Complex Modes 总被引:1,自引:0,他引:1
IntroductionMatrixperturbationmethodsforthedynamicreanalysisofself_adjointsystemshavebeenwelldeveloped[1] .However,manysystemsgiverisetogeneralnon_self_adjointformulations.Importantexamplesareaeroelasticstabilityofsystems,arbitrarilydampedorgyroscopicsys… 相似文献