Materials Literature
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X-ray photoemission and synchrotron-radiation photoemission were used to study the reaction of metals and molecular oxygen at low temperatures. Combined core-level and valence-band measurements permit the identification of various oxygen species. When Li, Cs, K, and La are deposited on solid oxygen, an O 1s feature ne…
We develop a model to explain the universal low-temperature properties of glasses in the 1T10 K temperature range. Our model consists of elastic dipole ``defects'' which are placed randomly in an elastic continuum. We derive a Hamiltonian for defects interacting via their long-range strain fields. We simulate a system…
We derived equations for the target-strength term used in the modified hydrodynamic model that describes long rod penetration into ceramic targets. Since ceramics have tensile strengths that are usually an order of magnitude lower than their compressive strength, this model allows for tensile cracking. In addition, ou…
As many as thirty-seven $^{2\mathit{S}+1}$${\mathit{L}}_{\mathit{J}}$ multiplet manifolds of ${\mathrm{Nd}}^{3+}$(4${\mathit{f}}^{3}$) have been analyzed in the garnets ${\mathrm{Y}}_{3}$${\mathrm{Al}}_{5}$${\mathrm{O}}_{12}$ (YAG), ${\mathrm{Y}}_{3}$${\mathrm{Sc}}_{2}$${\mathrm{Al}}_{3}$${\mathrm{O}}_{12}$ (YSAG), ${…
We have reinvestigated the use of ionizing radiations to measure the molecular mass of water-soluble or membrane proteins. The test was performed by using the most straightforward aspect of the technique, which consists of SDS/PAGE analysis of the protein-fragmentation process. We found that exposure of purified stand…
High-purity silicas synthesized by various manufacturing methods were studied by electron-spin resonance after being irradiated by ArF excimer laser (6.4 eV) at room temperature. E' centers (?Si\ensuremath{\cdot}) are induced in all samples, while nonbridging oxygen hole centers (?Si-O\ensuremath{\cdot}) appear only i…
Affinement dans P nam avec a=23,490, b=21,245, c=4,020 A, Z=4, R=0,077. Discussion de l'arrangement de base des atomes et de la distribution des cations determines par l'affinement d'occupation de site et par l'analyse des liaisons de valence. Comparaison avec les resultats obtenus auparavant
A computational technique is proposed for the analysis of optical absorption spectra for a variety of materials in terms of the well established power law for the optical absorption coefficient. Values of the power index n and optical energy gap E 0 can be obtained from a linear plot using the standard method of numer…
Fabrication and characterisation of photoelectrochemical solar cells employing flux-grown copper tungstate single crystals have been accomplished. Mott-Schottky plots have been drawn to provide a useful estimation of the properties of CuWO 4 from the measurements, and thus the nature and the values of the parameters N…
A synthetic five-part molecular device has been prepared that uses a multistep electron transfer strategy similar to that of photosynthetic organisms to capture light energy and convert it to chemical potential in the form of long-lived charge separation. It consists of two covalently linked porphyrin moieties, one co…
Introduction Molecules have been found to exist in a rich variety of astrophysical environments, including stellar atmospheres, comets, planetary atmospheres, and the dense and diffuse clouds in the interstellar medium. An understanding of molecular structure, spectroscopy, and photoabsorption processes is thus of cri…
The structural bovine eye lens protein alpha-crystallin was dissociated in 7 M urea and its four subunits, A1, A2, B1, and B2, were separated by means of ion-exchange chromatography. Homopolymeric reaggregates of these subunits were prepared by removal of the denaturant via dialysis. It was found that subunits were ex…
We have previously shown [Goto, Y., Calciano, L. J., & Fink, A. L. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 573-577] that beta-lactamase, cytochrome c, and apomyoglobin are maximally unfolded at pH 2 under conditions of low ionic strength, but a further decrease in pH, by increasing the concentration of HCl, refolds t…
Hydrogen passivation of deep traps in diamond is demonstrated. Current-voltage (I-V) characteristics of polycrystalline thin film and bulk diamond were studied before and after hydrogenation. On hydrogenation, all the samples showed several orders of magnitude increase in conductivity. Hydrogenation was carried out un…
Abstract Understanding the rate dependencies of the tensile strength of reinforcing fibres is a key for the understanding of the rate dependencies of the properties of the corresponding composite materials. Hence, in this study it is attempted to clarify the mechanical responses of aramid and carbon fibres at differen…
Ultraviolet photoelectron spectra (UPS) have been measured for bare unsupported copper clusters in the 1--410 atom size range as mass selected from a supersonic, negatively charged, cluster ion beam. Using an ${\mathrm{F}}_{2}$ excimer laser at 7.9 eV, the UPS patterns display the evolution of the 3d band structure as…
Theoretical and experimental results are reported which provide the first evidence for biexciton states in semiconductor quantum dots. The theory predicts an increasing biexciton binding energy with decreasing dot size. Unlike bulk semiconductors, quantum dots have excited biexciton states which are stable. These biex…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotosensitized electron-transfer reactions and hydrogen evolution in organized microheterogeneous environments: separation of ground-state xanthene-bipyridinium complexes by silica colloidsI. Willner, Y. Eichen, and E. JoselevichCite this: J. Phys. Chem. 1990, 94, 7, 3092–3…
Abstract Composite latex particles based on natural rubber latex have been synthesized to yield materials which may be formally regarded as interpenetrating polymer networks and semiinterpenetrating polymer networks. Methyl methacrylate was added to a carefully stabilized natural rubber latex and polymerized in situ u…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOptical nonlinearities of organometallic structures: aryl and vinyl derivatives of ferroceneSaswati. Ghosal, Marek. Samoc, Paras N. Prasad, and Joseph J. TufarielloCite this: J. Phys. Chem. 1990, 94, 7, 2847–2851Publication Date (Print):April 5, 1990Publication History Publi…