Materials Literature
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We recently have shown that a negative streamer in a sufficiently high homogeneous field can branch spontaneously due to a Laplacian instability, rather than approach a stationary mode of propagation with fixed radius. In our previous simulations, the streamer started from a wide initial ionization seed on the cathode…
A method for incorporating electromagnetic fields into empirical tight-binding theory is derived from the principle of local gauge symmetry. Gauge invariance is shown to be incompatible with empirical tight-binding theory unless a representation exists in which the coordinate operator is diagonal. The present approach…
We review various isotope effects in the high-T_c cuprate superconductors to assess the role of the electron-phonon interaction in the basic physics of these materials. Of particular interest are the unconventional isotope effects on the supercarrier mass, on the charge-stripe formation temperature, on the pseudogap f…
Quantitatively-unexplained stationary waves or ridges often encircle icicles. Such waves form when roughly 0.1 mm-thick layers of water flow down the icicle. These waves typically have a wavelength of 1cm approximately independent of external temperature, icicle thickness, and the volumetric rate of water flow. In thi…
A pulse-modulated plasma irradiation technique was applied to hydrogenation of ZnO. Three kinds of ZnO samples were employed to investigate the electronic state of hydrogen in ZnO. Secondary-ion-mass-spectroscopy analysis using isotope tracer revealed that the surface layer to 100 nm was doped with hydrogen after the…
Preface.Introduction, Safety and Instrumentation. The Chemical Dissolution of Silicon. The Semiconductor--Electrolyte Junction. The Electrochemical Dissolution of Silicon. Anodic Oxidation. Electrochemical Pore Formation. Microporous Silicon. Mesoporous Silicon. Macroporous Silicon. Applications.AppendicesSupplier Ref…
Polymer Science and Technology, Chonbuk National University, Chonju, Chonbuk 561-756, KoreaDepartment of Chemistry, Kunsan National University, Kunsan, Chonbuk 573-701, KoreaReceived November 27, 2001Keywords : Raman, Liquid crystal, Intermolecular interaction, Coil effect, Hydrogen bonding.IntroductionLiquid crystall…
Carbon nanotubes were placed in magnetic fields of 80.0 kOe at temperatures of 231 K and 314 K. Scanning electron microscopy showed that nanotubes were oriented with the tube axis parallel to the fields. It was also observed that the probability of the orientation became higher, when the temperature was raised from…
Photocrosslinkable chalcone-epoxy compound comprising 1,3-bis-(4-hydroxy-phenyl)-propenone was synthe-sized for fabricating the photo-alignment layer of liquid crystals. Chalcone group was introduced into the main chain unit of the epoxy oligomer. We observed a photodimerization behavior and an optical anisotropy of t…
The development of the dynamic glass transition in styrene-butadiene copolymers has been investigated by dielectric spectroscopy in the frequency range from 10 -2 to 10 6 Hz. Two processes were detected and attributed to the α - and β - relaxations. The α relaxation time has a non-Arrhenius temperature behavior that i…
Time-resolved infrared spectral measurements were made successfully for studying the microscopic mechanism of water-induced solid-state phase transitions of poly(ethylene imine) (PEI) in the hydration process at room temperature. The initial sample, obtained by cooling the melt under a dry atmosphere, showed the infra…
We have used ab initio quantum chemical techniques to compute the (13)C(alpha) and (13)C(beta) shielding surfaces for the 14 amino acids not previously investigated (R. H. Havlin et al., J. Am. Chem. Soc. 1997, 119, 11951-11958) in their most popular conformations. The spans (Omega = sigma(33) - sigma(11)) of all the…
Negatively charged polystyrene latex was synthesized, and a copolymer shell of 2-(methyl-2‘-chloropropionato)ethyl acrylate (HEA-Cl) and styrene was added, from which poly( N, N -dimethylacrylamide) (PDMA) was polymerized by atom transfer radical polymerization in aqueous suspension at room temperature. Increasing mon…
We actuated poly(vinyl chloride) (PVC) gel by applying a do field, and found localized creeping deformation, which induced swift, huge bending like a joint. The bending angle reached ca.150° at maximum at the field of 1000 V mm-1 with the velocity of ca. 90° s-1. The electric current was very small and in the range of…
Novel binary-phase WS 2 −C nanotubes were generated by pyrolyzing WO 3 -coated multiwalled carbon nanotubes in an H 2 S/N 2 atmosphere at 900 °C. The WS 2 coating acts as an anti-oxidizing agent.
We have prepared a new discotic nematogen, bearing one functional tail and five methoxy substituents. The corresponding side chain polymers, prepared via a polymer analogous esterification reaction, exhibited N D phases from 50 °C until degradation above 200 °C. Addition of equimolar amounts of various trinitrofluoren…
New heterospin complexes of Cu(hfac)2 (hfac, hexafluoroacetylacetonate) with pyrazole-substituted nitronyl nitroxides have been found that in the solid state exhibit thermally induced spin transitions analogous to spin crossover. For the first complex, [Cu(hfac)2Li-Pr], at room temperature, the Cu—OL distances, where…
Bimetallic monolayer-protected nanoparticles have been synthesized by the core metal galvanic exchange reaction of dodecylthiolate monolayer-protected metal (Ag, Pd, Cu) clusters with the more noble metal metal thiolate complexes Au I [SCH 2 (C 6 H 4 )C(CH 3 ) 3 ] and Pd II [S(CH 2 ) 11 CH 3 ) 2 ]. The bimetal nanopar…
Exchanger-OsO(4) catalysts are prepared by an ion-exchange technique using layered double hydroxides and quaternary ammonium salts covalently bound to resin and silica as ion-exchangers. The ion-exchangers with different characteristics and opposite ion selectivities are specially chosen to produce the best heterogene…
X-ray diffraction, resistivity, ac susceptibility and magnetization studies on La0.67Ca0.33Mn1-xRuxO3 (0 x < 0.1) were carried out. A significant increase in the lattice parameters indicated the presence of mixed valance state of Ru: Ru3+ and Ru4+. The resistivity of the doped compounds exhibited two features: a broad…