Materials Literature
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Abstract Variations I–XVIII of a trimerlike cross‐linked collagen model peptide were synthesized and used to investigate the cooperation of different neighboring Gly‐X‐Y tripeptides. The carboxy‐terminal decapentapeptide of the tripe‐helical part of collagen type I was chosen as the starting point of sequentially modi…
Time-resolved laser-induced fluorescence (LIF) measurements have been carried out on the kinetics of CN(v= 0) and CN(v= 1) radicals with O2, NH3 and NO at temperatures between 294 and 761 K. The radicals were generated by pulsed laser photolysis of NCNO at 532 nm, and the decays of concentration were monitored using a…
For binary aqueous solvent mixtures the solvent composition in the first solvation sphere of Eu3+ has been determined at 25 °C by measuring the luminescence lifetime. In the systems water–acetone, water–acetonitrile and water–1,4-dioxane the first solvation sphere of Eu3+ is exclusively occupied by water molecules eve…
Abstract We review the effects of temperature on conductance and viscosity in the liquid state of vitreous ionic conductors and show how differences may be best understood by comparison of relaxation times for electrical and mechanical stresses acting on liquid or glassy states of the material. This leads to the defin…
In microcanonical molecular dynamics the conservation of total momentum implies that the trajectories generate an ensemble with constant total momentum. We present the exact statistical mechanics of this microcanonical molecular dynamics ensemble. Using the adiabatic invariant phase volume to define the entropy, exact…
Poly(3-methylthiophene) thin films with conductivities in the range of 2000 S cm–1 have been prepared by electrochemical polymerization.
Abstract We report the first ion implantation doping studies on high‐temperature ladder polymers and show that insulting films of the benzimidazobenzophenanthroline‐type ladder polymer (BBL) can be doped by boron, argon, and krypton implantation to conductivities as high as 224 S/cm at a dose of 4.0 × 10 16 /cm 2 whil…
A phosphotungstate-anion (PT)-incorporated polypyrrole (PPy/PT) electrode has been prepared by electrochemical polymerization in water containing both pyrrole and the sodium salt of PT. The PPy/PT electrode showed two redox peaks accompanying electrochromism. The peak at higher potential corresponds to an oxidation–re…
Audio frequency electrical conductivity, DSC, DMA, and 23 Na NMR measurements have been carried out on Parel 58 elastomer complexed with sodium perchlorate. [As Parel 58 is primarily poly(propylene oxide), it will be referred to as PPO.] The DSC and DMA measurements yield similar values for which are about 72°C higher…
The purpose of the present work is to predict, from physical bases, the mechanical behaviour of amorphous polymers resulting from the application of a periodic stress through the glass transition range (a relaxation). A theory of the non elastic deformation is developed from a model of molecular mobility. The amorphou…
A complete solution of plane-wave scattering from a groove-corrugated surface of infinite extent for arbitrary incidence is presented. The electromagnetic wave is decomposed into fast and slow modal representation, and the solution is accomplished through the use of the mode-matching method. We solved for the zero-ord…
Résumé. 2014 Nous étudions les empilements denses de particules avec des interactions qui favorisent la symétrie pentagonale. Ces structures peuvent être obtenues par décoration de pavages de Penrose ou directement par une méthode de coupe et projection. Nous prouvons qu’elles forment l’état fondamental dégénéré, dans…
The complete amino acid sequence of 6-phospho-fructo-2-kinase/fructose-2,6-bisphosphatase from rat liver was determined by direct analysis of the S-carboxamidomethyl protein. A complete set of nonoverlapping peptides was produced by cleavage with a combination of cyanogen bromide and specific proteolytic enzymes. The…
Abstract
A yolk protein, egg-specific protein, synthesized and accumulated in the developing ovaries of Bombyx mori serves not only as the nutritive source for embryogenesis but also for the reorganization of the yolk system through limited degradation. Using the purified egg-specific protein as a substrate, a protease respons…
Methods to deduce the parameters of a multilayer X-ray mirror from its reflectivity curve are reviewed. Inversion methods are successful for coatings with few layers and give the thickness of each layer and the roughness of each interface. A statistical description of the coating is used for coatings with many layers,…
Abstract Liquid crystalline phthalocyanines with eight n ‐alkoxy chains have been synthesized and their mesophase structures determined by X‐ray diffraction. The mesophases appear to be of the D ho type. Reasons for the preference of ordered columns are discussed.
Organized monolayer structures prepared on polar solids via spontaneous adsoption from organic solutions (self-assembly) exhibit some rather unique features, particularly relevant with regard to possible technological applications of such systems.
A homogeneous dislocation distribution in deformed metals is unstable with respect to clustering of dislocation dipoles. The main reason for formation of the dislocation clusters is a net dipole drift to stress concentrations created by glide dislocations in a applied stress state. Linear stability analysis indicates…
The theory of electromigration is focused on the force acting on a lattice defect in a metallic sample that carries an electric current. Much work has been done to obtain a better understanding of the underlying physical mechanisms. The force has been calculated numerically for defects in several metals, and a qualita…