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891.
The influence of casting parameters on the surface morphology of PS‐b‐P4VP honeycomb films 下载免费PDF全文
Ao Chen Idriss Blakey Andrew K. Whittaker Hui Peng 《Journal of polymer science. Part A, Polymer chemistry》2016,54(23):3721-3732
The “breath figures” method provides an efficient and cost‐effective method to produce highly ordered honeycomb patterns in polymeric films at micrometer and sub‐micrometer dimensions. The size and regularity of the pores can be adjusted through a series of physical and chemical parameters. In this study, amphiphilic diblock copolymers, polystyrene‐block‐poly(4‐vinyl pyridine) (PS‐b‐P4VP) with different lengths of P4VP, were synthesized through Reversible Addition‐Fragmentation Chain Transfer polymerization. The honeycomb‐patterned films were prepared from these well‐defined polymers through the dynamic breath figures method. A series of physical parameters including solution concentration, flow rate, humidity of the flow, and the humidity of the casting environment, were delicately adjusted to systematically investigate their effects on the morphology of the films. These studies identified four key factors which were found to influence the formation of the pattern. No obvious effect was found on the pore size by changing the length of P4VP block. The result provides clear direction on the fabrication of PS‐b‐P4VP honeycomb‐patterned films and more broadly contributes a deeper understanding of the processes involved in the formation of honeycomb patterns. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3721–3732 相似文献
892.
Acta Mathematica Sinica, English Series - Let X be a regular curve and n be a positive integer such that for every nonempty open set U ⊂ X, there is a nonempty connected open set V ⊂ U... 相似文献
893.
Ya‐Guang Sun Prof. Dr. Shu‐Ting Rong Wan Yu Yong‐Li Wu Fu Ding En‐Jun Gao Wan‐Zhong Zhang Francis Verpoort 《无机化学与普通化学杂志》2009,635(15):2585-2591
4‐Hydroxypyridine‐2,6‐dicarboxylic acid (H3CAM) reacts with Ln2O3(Ln = La, Ce) or Ln(NO3)3 (Ln = Sm, Dy, Gd, Ho) in hydrothermal reactions to form a series of lanthanide coordination polymers 1 – 6 . Elemental analysis, IR spectra and X‐ray crystal structure analysis were carried out to determine the composition and crystal structure of 1 – 6 . Compounds 1 and 2 are isostructural and contain tetranuclear metallic ring unit and 3D framework. 4 – 6 are isostructural contain 2D network. Furthermore, the photoluminescent properties of 3 and 4 at room temperature were also studied. 相似文献
894.
采用水热法,以3 mol/L的KOH作为矿化剂,在260℃下,保温24 h左右,进行Ni掺杂(x=0.1 mol),合成Zn1-xNixO稀磁半导体晶体。XRD测试表征以KOH作为矿化剂能够制备出发育良好的Zn0.9Ni0.1O稀磁半导体晶体,没有其它杂质相的产生。通过UV/Vis测试进一步说明掺杂的效果,掺杂使ZnO的禁带宽度降低至3.18 eV。FE-SEM测试显示所制备的晶体呈现长柱状。VSM测试表明,所制备的样品Zn0.9Ni0.1O在室温下表现出铁磁性。文章采用水热法制备出了具有铁磁性能的稀磁半导体粉体。 相似文献
895.
N-doped TiO2 nanotube arrays (NTN) were prepared by anodization and dip-calcination method. Hydrazine hydrate was used as nitrogen source. The surface morphology of samples was characterized by SEM. It showed that the mean size of inner diameter was 65 nm and wall thickness was 15 nm for NTN. The ordered TiO2 nanotube arrays on Ti substrate can sustain the impact of doping process and post-heat treatment. The atomic ratio of N/Ti was 8/25, which was calculated by EDX. Photoelectrochemical property of NTN was examined by anodic photocurrent response. Results indicated the photocurrent of NTN was nearly twice as that of non-doped TiO2 nanotube arrays (TN). Photocatalytic activity of NTN was investigated by degrading dye X-3B under visible light. As a result, 99% of X-3B was decomposed by NTN in 105 min, while that of TN was 59%. 相似文献
896.
用原子力显微镜观察了阴阳离子菁染料及对应的阴离子菁染料和阳离子菁染料吸附在立方体(100)和八面体(111)溴碘化银乳剂颗粒表面形成的J-聚集体的微观结构,得到了3种不同排列的J-聚集体结构。研究结果表明,菁染料分子在溴碘化银颗粒表面不是单层吸附,而是以一定的形状聚集在溴碘化银表面。阴阳离子菁染料形成的J-聚集体为"鱼骨"状;阴离子菁染料的J-聚集体以"卡片堆积"式排列;阳离子菁染料J-聚集体为"磁砖"式结构。 相似文献
897.
898.
钚因放射性衰变而出现老化效应.钚中点缺陷的性质和行为是理解钚老化效应的一个基础和前提.运用分子动力学模拟技术,计算了金属钚中点缺陷和点缺陷团簇的形成能和结合能.其中钚-钚、钚-氦和氦-氦相互作用势分别采用嵌入原子多体势、Morse对势和Lennard-Jones对势.计算结果表明,单个自间隙原子易以〈100〉哑铃状形态存在;间隙氦原子在理想晶格的八面体间隙位置相对较为稳定;氦原子与空位的结合能较大,在钚的自辐照过程中两者易于结合并形成氦-空位团簇;氦-空位团簇的形成能随氦原子数的增加而增大,当氦与空位的数 相似文献
899.
Weiwei Ao Hardy Chan Azahara DelaTorre Marco A. Fontelos Marí a del Mar Gonzá lez & Juncheng Wei 《数学研究》2020,53(4):370-401
Non-local equations cannot be treated using classical ODE theorems. Nevertheless, several new methods have been introduced in the non-local gluing scheme
of our previous article; we survey and improve those, and present new applications as
well. First, from the explicit symbol of the conformal fractional Laplacian, a variation
of constants formula is obtained for fractional Hardy operators. We thus develop, in
addition to a suitable extension in the spirit of Caffarelli–Silvestre, an equivalent formulation as an infinite system of second order constant coefficient ODEs. Classical
ODE quantities like the Hamiltonian and Wrońskian may then be utilized. As applications, we obtain a Frobenius theorem and establish new Pohožaev identities. We also give a detailed proof for the non-degeneracy of the fast-decay singular solution of the
fractional Lane–Emden equation. 相似文献
900.
By using the variational Lyapunov method and Razumikhin technique, the stability criteria in terms of two measures for impulsive delay differential systems are established. The known results are generalized and improved. An example is worked out to illustrate the advantages of the theorems. 相似文献