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1.
Hana Macková Daniela Králová Daniel Horák 《Journal of polymer science. Part A, Polymer chemistry》2007,45(24):5884-5898
The aim of this study was to develop novel thermally responsive polymer microspheres with magnetic properties. Dispersion and inverse emulsion copolymerization of N‐isopropylacrylamide (NIPAAm) and N,N′‐methylenebisacrylamide (MBAAm) was investigated in the presence of γ‐Fe2O3 nanoparticles. The resulting microspheres were characterized in terms of morphology, size, polydispersity, iron content, and temperature‐dependent swelling using optical microscopy, transmission electron microscopy, scanning electron microscopy, QELS, and AAS. The effects of several variables, such as the concentration of γ‐Fe2O3, MBAAm crosslinking agent, Span 80 surfactant, 2,2′‐azobis(2‐methyloctanenitrile) (AMON) initiator, and polymerization temperature on the properties of the microspheres were studied. Swelling and thermoresponsive behavior of the microspheres containing γ‐Fe2O3 nanoparticles were also investigated. The microspheres contained about 8 wt % of iron. The presence of magnetic nanoparticles and their concentration changes did not have any significant effect on the temperature sensitivity of the composites. The particles gradually shrink into an increasingly collapsed state when the temperature is raised to 40 °C since the increase in temperature weakens the hydration and PNIPAAm chains gradually become more hydrophobic, which leads to the collapse of the particles. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5884–5898, 2007 相似文献
2.
A tree T is arbitrarily vertex decomposable if for any sequence τ of positive integers adding up to the order of T there is a sequence of vertex-disjoint subtrees of T whose orders are given by τ. An on-line version of the problem of characterizing arbitrarily vertex decomposable trees is completely solved here. 相似文献
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4.
A proper edge colouring of a graph G is neighbour-distinguishing provided that it distinguishes adjacent vertices by sets of colours of their incident edges.
It is proved that for any planar bipartite graph G with Δ(G)≥12 there is a neighbour-distinguishing edge colouring of G using at most Δ(G)+1 colours. Colourings distinguishing pairs of vertices that satisfy other requirements are also considered. 相似文献
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6.
Beverina L Abbotto A Landenna M Cerminara M Tubino R Meinardi F Bradamante S Pagani GA 《Organic letters》2005,7(19):4257-4260
[graph: see text] Condensation of squaric acid with a number of differently substituted 2-pyrrolyl derivatives afforded three new classes of squaraines. Their sharp and intense absorption bands in the biological window (700-900 nm), inherent singlet oxygen generation capabilities, together with proper functionalization allowing good water solubility make them suitable candidates as new non-porphyrinic singlet oxygen photosensitizers for photodynamic therapy (PDT). 相似文献
7.
A. Torrisi P. Horák J. Vacík A. Cannavò G. Ceccio J. Vaniš 《Phosphorus, sulfur, and silicon and the related elements》2020,195(11):932-935
AbstractOn the perspective to develop CuO–TiO2 MOS, multilayered Cu and Ti thin layers were alternatively deposited on silicon wafers using 25?keV Ar?+?ion beam sputtering and, subsequently, oxidized by thermal annealing in air at 400?°C for 24?h. The deposited films have variable ratios of the Cu and Ti % at. One of the main goal is to obtain such multilayers avoiding the presence of Cu–Ti–O compounds. The samples were characterized in terms of composition (by RBS and SIMS analyses) and morphology (by AFM and SEM investigations). In particular, SIMS maps allows to observe the spatial distribution and thickness of each phase of the Cu/Ti multilayers, and further to observe Cu diffusion and mixing with Ti, as well as phase separation of CuO and TiO2 in the samples. The reasons of this effect represent an open issue that has to investigated, in order to improve the MOS fabrication. 相似文献
8.
Precise values of energies and widths of low-lying resonances in some rare-gas atom systems (Ar-Ar, Ne-Kr, Ne-Xe) are reported. 相似文献
9.
The problem of calculation of Sturmian functions (positive energy Weinberg states) for nonlocal (exchange) interactions is considered. It is shown that the method of continued fractions proposed by Horáek and Sasakawa makes the calculation of Sturmian eigenfunctions and eigenvalues feasible even for complicated nonlocal interactions. As an example Sturmian functions and Sturmian eigenvalues for the low energy electron-hydrogen scattering in the static exchange approximation are calculated. In addition a very general proof of convergence of the method of continued fractions is presented.Dedicated to the memory of Professor Jozef Kvasnica. 相似文献
10.
G. Horányi 《Journal of Radioanalytical and Nuclear Chemistry》1989,137(1):23-28
The role of electrochemistry in the discovery and interpretation of the alleged cold nuclear fusion is discussed. 相似文献