A new and simple method for the fabrication of densely packed magnetic nanodot arrays was developed using conventional sputtering deposition at room temperature. An anodized alumina template was employed for the formation of nanodot assemblies, consisting of carbon nanotubes (CNTs) and magnetic nanodot arrays. Each nanodot was formed exactly on top of a CNT and was arranged with a well-ordered structure in a wide range of area. It was also found that the size of dots and the distance between dots can be tailored by changing the length of CNTs, inducing a change of strength of dipolar interaction between nanodots.

High‐resolution 13Carbon nuclear magnetic resonance (NMR) spectra of Nylons 4, 6, and 66 in the solid state were measured over a wide range of temperature. From the results, it was found that resonance lines of crystalline and noncrystalline components were separable and their chemical shifts were determined. The 13C chemical shift behavior is closely related to their conformation. The origin of the conformational effects on the chemical shifts is discussed.

High resolution 13C‐NMR spectra of nylon 6 samples crystallized under various conditions and of a drawn sample were measured at room temperature by the cross polarization/magic angle spinning (CP/MAS) and pulse saturation transfer/magic angle spinning techniques. Additionally, 13C‐NMR spectra of the drawn sample were measured at temperatures from 20 to 100°C by the CP/MAS technique and at 20 and 100°C by the low‐power decoupling/magic angle spinning technique. The nylon 6 structure in the solid‐state is discussed on the basis of these results. The solid‐state 13C chemical shift data are used for reference in a study of conformation in solution.

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Tsukiji 2-chome, Chuo-ku, Tokyo, 104 Japan) The branching degree of natural rubber (NR) estimated by GPC/LALLS measurement is higher than that of synthetic isoprene rubber (IR). Branched polymer chains and the gel networks of NR are easily decomposed by various means such as mechanical force, solvent power and enzymic deproteinization reaction. This decomposition leads to the increase of linear polymer chains.13C NMR spectrum of the low molecular weight fraction of NR gives small signals which are characteristics of an ester group. From these facts we estimate that the NR gel consists of weak linkages such as hydrogen bonds between an ester group in NR and an amino group in protein. Since the IR gel is formed by chemical bonds, it can be randomly decomposed only by mechanical force; this results in the increase of branched polymer chains. The gel structures of NR and IR are directly observed by transmission electron microscopy. The networks of NR gel show looser than those of IR gels.