Materials Literature
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Interest in the naphthalene unit is increasing considerably. Recently, low and high molecular mass mesogens of naphthalene derivatives exhibiting attractive properties have been reported in the literature. In the present study, three mesogenic homologous series containing a naphthalene moiety have been synthesized. Al…
Research on metal diffusion into polymers and metal–polymer interfaces is mainly stimulated by applications of polyimide in microelectronics packaging and at the chip level. Since copper will increasingly replace aluminum in such applications as a result of miniaturization, the interfacial behavior of copper is of gre…
The structure of the (-)-(7S,8R,9S,10R)-N6-[10-(7,8,9, 10-tetrahydrobenzo[a]pyrenyl)]-2'-deoxyadenosyl adduct at A7 of 5'-d(CGGACAAGAAG)-3'.5'-d(CTTCTTGTCCG)-3', derived from trans addition of the exocyclic N6-amino group of dA to (-)-(7S,8R,9R, 10S)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(-)-DE2]…
The deposition of SiO2 films from novel alkoxysilane/O2 rf plasmas has been investigated using tetraethoxysilane and the novel alkoxysilanes, triethoxysilane, tetramethoxysilane, and trimethoxysilane. We have demonstrated that high quality SiO2 films can be deposited from each of these alkoxysilanes under similar cond…
Aspartate aminotransferase (AspAT) is a unique enzyme that can react with two types of substrate with quite different properties, acidic substrates, such as aspartate and glutamate, and neutral substrates, although the catalytic group Lys-258 acts on both types of substrate. The dynamic properties of the substrate-bin…
Acid phosphatase activity in the blood serum is usually separated into tartrate-resistant and tartrate-refractory, which is reported as the prostatic acid phosphatase level. Human prostatic acid phosphatase crystals soaked in N-propyl-L-tartramate were used to collect x-ray diffraction data to 2.9 A resolution under c…
Solvent excess chemical potentials in amorphous polymers were calculated by means of molecular dynamics simulations using two different methods, the thermodynamic integration method and an extended ensemble method, during which the coupling of a test particle with the rest of the system is continuously changing. The l…
Although known for more than thirty years, the physical nature of the glass-transition crossover region is still an open question. Heat capacity spectroscopy experiments in the crossover region of poly( n -hexyl methacrylate) are presented which indicate, for the first time, that the dynamic glass transition consists…
${\mathrm{B}}_{2}{\mathrm{O}}_{3}$ in glass and crystalline states have been subjected to \ensuremath{\gamma} irradiation at room temperature and subsequently studied by continuous-wave electron paramagnetic resonance and electron-spin-echo envelope modulation (ESEEM) spectroscopy at liquid-helium temperature. The ESE…
The nonlinear vibratory behavior of a 1-3 piezoceramic composite is characterized theoretically and experimentally. The developed theoretical model for the electroelastic behavior of the 1-3 composite follows conventional assumptions made by prior investigators but includes nonlinear terms to account for hysteresis in…
A numerical solution to the problem of existence and stability of topological solitons in a polyethylene chain surrounded by immovable neighboring chains is obtained. In the framework of a realistic model that takes into account deformations of valence bonds, valence and torsional angles, as well as intermolecular int…
Oversized dopant ions such as yttrium and lanthanum segregate to grain boundaries and reduce the tensile creep rate of α‐Al 2 O 3 by 2‐3 orders of magnitude. One explanation for this behavior is that the oversized segregants give rise to a “site‐blocking” effect for grain boundary diffusion. It has also been speculate…
By using polarized infrared absorption spectroscopy, we have determined the average inclination angle of the backbone structure of a series of polyimides with alkyl side chains induced by rubbing. We examined four polyimides. They have an identical backbone structure, but the number (n) of carbon atoms in the alkyl si…
D2AM is a french CRG beamline installed at the ESRF (European Synchrotron Radiation Facility) in Grenoble, with half of the time dedicated to biological macromolecule crystallography and half to materials science studies (diffraction, wide-angle and small-angle scattering). It is constructed at the front-end BM02 of t…
Optical absorption spectra of amorphous $\mathrm{CsPb}{X}_{3}$ films $(X=\mathrm{B}\mathrm{r},\mathrm{C}\mathrm{l})$ are characterized by two Gaussian bands near the fundamental edge, with the optical energy gap largely blueshifted and the absorption intensity strongly reduced as compared with the crystalline films. T…
The title selenocycle-fused tetrathiafulvalene derivatives (BES-TTF and DS-TTF) and tetraselenafulvalene derivative (BES-TSF) have been synthesized as novel electron donors, and their conducting molecular complexes have been studied. Although DS-TTF formed only semiconducting complexes, BES-TTF and BES-TSF gave metall…
The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropolymerization of the parent monomers has been investigated and has emphasized the critical importance of the solvent used. Indeed, the intensity of the inhibition peak, which is the electrochemical mark o…
Powder diffraction offers a wide spectrum of applications to solid-state scientists. The method traditionally used for phase analysis and the study of structural imperfections has benefited, in the last twenty years, from great advances in the instrumentation and computer-based approaches for pattern indexing and mode…
The incorporation of silicon into boron nitride films (BN:Si) has been achieved during ion beam assisted deposition growth. A gradual change from cubic boron nitride (c-BN) to hexagonal boron nitride (h-BN) was observed with increasing silicon concentration. Ultraviolet photoelectron spectroscopy, field emission, and…
Time-resolved crystallography has been successfully applied on the time scale from seconds via milliseconds and nanoseconds to picoseconds on a variety of systems. This brief review largely deals with macromolecular systems, on which there has been substantial recent progress. The strategies for design of a successful…