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911.
The surface-deformation characteristics of uniaxially drawn poly(ethylene terephthalate) (PET) film were successfully evaluated with multiline scratch tests using scanning probe microscopy (SPM) on a nanometer scale. The PET film was prepared by compression molding from the melt, followed by quenching in ice water. The obtained amorphous film was drawn uniaxially below its glass-transition temperature, and the resultant surface roughness could be reduced to within 5 nm. A multiline scratch with the Si(3)N(4) tip of an SPM on the oriented PET surface was made parallel and perpendicular to the drawing axis under applied loads of 5-30 nN. The perpendicular scratching generated a characteristic periodic pattern on the film surface, but the parallel scratching induced a tearing of the surface. These results suggest that surface-deformation mechanisms were dominated by molecular anisotropy. The surface-deformation properties, as evaluated from scratch-angle dependences on morphological changes on a nanometer scale, were similar to the mechanical properties of the bulk.  相似文献   
912.
Flexible honeycomb gold films supported by polymer sheets are fabricated by using polystyrene particle monolayers. The surfaces of the flexible gold films are covered with self-assembled monolayers (SAMs) of hydrophobic or hydrophilic thiol compounds, and the wettability of the modified surface is evaluated by measurements of the contact angles of water droplets. The contact angle of the film covered with hydrophobic SAM is ca. 150 degrees, which is greater than the value of 112 degrees for a flat gold surface, while the values for hydrophilic SAM are below 10 degrees.  相似文献   
913.
To build up finely designed patterns on solid surfaces, consecutive vapor-phase assisted surface photo-polymerization (VASP) of methyl methacrylate and styrene was carried out under UV-irradiation through a stripe-patterned photo-mask on Si-wafer and Au-plate surfaces, resulting in the reproduction of designed and multi-layered patterns made of block copolymer chains grafted from the surfaces.  相似文献   
914.
Photoinduced electron transfer between a porphyrin and a new guest cyclodextrin bearing viologen occurs by a supramolecular formation with conformational change of a guest molecule.  相似文献   
915.
916.
917.
We show here that La@C72 has a non-IPR cage, unique electronic properties, and high reactivity by the spectroscopic and X-ray crystallographic analysis and the theoretical study. The isolation of La@C72 as a stable derivative might constitute an important stepping-stone on the way to isolation of these unknown metallofullerenes and open new material science of metallofullerenes.  相似文献   
918.
The structural analysis of natural protein fibers with mixed parallel and antiparallel beta-sheet structures by solid-state NMR is reported. To obtain NMR parameters that can characterize these beta-sheet structures, (13)C solid-state NMR experiments were performed on two alanine tripeptide samples: one with 100% parallel beta-sheet structure and the other with 100% antiparallel beta-sheet structure. All (13)C resonances of the tripeptides could be assigned by a comparison of the methyl (13)C resonances of Ala(3) with different [3-(13)C]Ala labeling schemes and also by a series of RFDR (radio frequency driven recoupling) spectra observed by changing mixing times. Two (13)C resonances observed for each Ala residue could be assigned to two nonequivalent molecules per unit cell. Differences in the (13)C chemical shifts and (13)C spin-lattice relaxation times (T(1)) were observed between the two beta-sheet structures. Especially, about 3 times longer T(1) values were obtained for parallel beta-sheet structure as compared to those of antiparallel beta-sheet structure, which could be explicable by the difference in the hydrogen-bond networks of both structures. This very large difference in T(1) becomes a good measure to differentiate between parallel or antiparallel beta-sheet structures. These differences in the NMR parameters found for the tripeptides may be applied to assign the parallel and antiparallel beta-sheet (13)C resonances in the asymmetric and broad methyl spectra of [3-(13)C]Ala silk protein fiber of a wild silkworm, Samia cynthia ricini.  相似文献   
919.
A single-component molecular conductor [Au(tmdt)2] (tmdt = trimethylenetetrathiafulvalenedithiolate) undergoes an antiferromagnetic phase transition at unprecedentedly high temperature (TN = 110 K). Black microcrystals of alloys, [Ni1-xAux(tmdt)2] (0.0 < x < 1.0) were prepared. The Au-rich system exhibited an antiferromagnetic transition. Metallic single crystal was obtained for x = 0.25.  相似文献   
920.
Complexation behavior of the paramagnetic La@C82 metallofullerene with organic donor molecules (D) in solution is investigated. It is revealed that La@C82 and D form a 1:1 complex as a result of electron transfer. La@C82 and D are in equilibrium with [La@C82]-/[D]*+ in solution, which is readily controllable by changing the temperature and solvent.  相似文献   
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